prepare for the transition to linux 2.6.22 - make it possible to override the kernel...

[openwrt.git] / target / linux / generic-2.6 / patches-2.6.22 / 510-Yaffs.patch

diff -urN linux-2.6.21.1/fs/Kconfig linux-2.6.21.1.new/fs/Kconfig
--- linux-2.6.21.1/fs/Kconfig   2007-06-08 14:07:09.000000000 +0200
+++ linux-2.6.21.1.new/fs/Kconfig       2007-06-08 14:09:26.000000000 +0200
@@ -419,6 +419,7 @@
 
 source "fs/xfs/Kconfig"
 source "fs/gfs2/Kconfig"
+source "fs/yaffs2/Kconfig"
 
 config OCFS2_FS
        tristate "OCFS2 file system support"
diff -urN linux-2.6.21.1/fs/Makefile linux-2.6.21.1.new/fs/Makefile
--- linux-2.6.21.1/fs/Makefile  2007-06-08 14:07:09.000000000 +0200
+++ linux-2.6.21.1.new/fs/Makefile      2007-06-08 14:09:51.000000000 +0200
@@ -116,3 +116,4 @@
 obj-$(CONFIG_DEBUG_FS)         += debugfs/
 obj-$(CONFIG_OCFS2_FS)         += ocfs2/
 obj-$(CONFIG_GFS2_FS)           += gfs2/
+obj-$(CONFIG_YAFFS_FS)         += yaffs2/
diff -urN linux-2.6.21.1/fs/yaffs2/Kconfig linux-2.6.21.1.new/fs/yaffs2/Kconfig
--- linux-2.6.21.1/fs/yaffs2/Kconfig    1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/Kconfig        2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,175 @@
+#
+# YAFFS file system configurations
+#
+
+config YAFFS_FS
+       tristate "YAFFS2 file system support"
+       default n
+       depends on MTD
+       select YAFFS_YAFFS1
+       select YAFFS_YAFFS2
+       help
+         YAFFS2, or Yet Another Flash Filing System, is a filing system
+         optimised for NAND Flash chips.
+
+         To compile the YAFFS2 file system support as a module, choose M
+         here: the module will be called yaffs2.
+
+         If unsure, say N.
+
+         Further information on YAFFS2 is available at
+         <http://www.aleph1.co.uk/yaffs/>.
+
+config YAFFS_YAFFS1
+       bool "512 byte / page devices"
+       depends on YAFFS_FS
+       default y
+       help
+         Enable YAFFS1 support -- yaffs for 512 byte / page devices
+         
+         Not needed for 2K-page devices.
+
+         If unsure, say Y.
+
+config YAFFS_9BYTE_TAGS
+       bool "Use older-style on-NAND data format with pageStatus byte"
+       depends on YAFFS_YAFFS1
+       default n
+       help
+
+         Older-style on-NAND data format has a "pageStatus" byte to record
+         chunk/page state.  This byte is zero when the page is discarded.
+         Choose this option if you have existing on-NAND data using this
+         format that you need to continue to support.  New data written
+         also uses the older-style format.  Note: Use of this option
+         generally requires that MTD's oob layout be adjusted to use the
+         older-style format.  See notes on tags formats and MTD versions.
+
+         If unsure, say N.
+
+config YAFFS_DOES_ECC
+       bool "Lets Yaffs do its own ECC"
+       depends on YAFFS_FS && YAFFS_YAFFS1 && !YAFFS_9BYTE_TAGS
+       default n
+       help
+         This enables Yaffs to use its own ECC functions instead of using
+         the ones from the generic MTD-NAND driver.
+
+         If unsure, say N.
+
+config YAFFS_ECC_WRONG_ORDER
+       bool "Use the same ecc byte order as Steven Hill's nand_ecc.c"
+       depends on YAFFS_FS && YAFFS_DOES_ECC && !YAFFS_9BYTE_TAGS
+       default n
+       help
+         This makes yaffs_ecc.c use the same ecc byte order as Steven
+         Hill's nand_ecc.c. If not set, then you get the same ecc byte
+         order as SmartMedia.
+
+         If unsure, say N.
+
+config YAFFS_YAFFS2
+       bool "2048 byte (or larger) / page devices"
+       depends on YAFFS_FS
+       default y
+       help
+         Enable YAFFS2 support -- yaffs for >= 2K bytes per page devices
+
+         If unsure, say Y.
+
+config YAFFS_AUTO_YAFFS2
+       bool "Autoselect yaffs2 format"
+       depends on YAFFS_YAFFS2
+       default y
+       help
+         Without this, you need to explicitely use yaffs2 as the file
+         system type. With this, you can say "yaffs" and yaffs or yaffs2
+         will be used depending on the device page size (yaffs on
+         512-byte page devices, yaffs2 on 2K page devices).
+
+         If unsure, say Y.
+
+config YAFFS_DISABLE_LAZY_LOAD
+       bool "Disable lazy loading"
+       depends on YAFFS_YAFFS2
+       default n
+       help
+         "Lazy loading" defers loading file details until they are
+         required. This saves mount time, but makes the first look-up
+         a bit longer.
+
+         Lazy loading will only happen if enabled by this option being 'n'
+         and if the appropriate tags are available, else yaffs2 will
+         automatically fall back to immediate loading and do the right
+         thing.
+
+         Lazy laoding will be required by checkpointing.
+
+         Setting this to 'y' will disable lazy loading.
+
+         If unsure, say N.
+
+config YAFFS_CHECKPOINT_RESERVED_BLOCKS
+       int "Reserved blocks for checkpointing"
+       depends on YAFFS_YAFFS2
+       default 10
+       help
+          Give the number of Blocks to reserve for checkpointing.
+         Checkpointing saves the state at unmount so that mounting is
+         much faster as a scan of all the flash to regenerate this state
+         is not needed.  These Blocks are reserved per partition, so if
+         you have very small partitions the default (10) may be a mess
+         for you.  You can set this value to 0, but that does not mean
+         checkpointing is disabled at all. There only won't be any
+         specially reserved blocks for checkpointing, so if there is
+         enough free space on the filesystem, it will be used for
+         checkpointing.
+
+         If unsure, leave at default (10), but don't wonder if there are
+         always 2MB used on your large page device partition (10 x 2k
+         pagesize). When using small partitions or when being very small
+         on space, you probably want to set this to zero.
+
+config YAFFS_DISABLE_WIDE_TNODES
+       bool "Turn off wide tnodes"
+       depends on YAFFS_FS
+       default n
+       help
+         Wide tnodes are only used for NAND arrays >=32MB for 512-byte
+         page devices and >=128MB for 2k page devices. They use slightly
+         more RAM but are faster since they eliminate chunk group
+         searching.
+
+         Setting this to 'y' will force tnode width to 16 bits and save
+         memory but make large arrays slower.
+
+         If unsure, say N.
+
+config YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+       bool "Force chunk erase check"
+       depends on YAFFS_FS
+       default n
+       help
+          Normally YAFFS only checks chunks before writing until an erased
+         chunk is found. This helps to detect any partially written
+         chunks that might have happened due to power loss.
+
+         Enabling this forces on the test that chunks are erased in flash
+         before writing to them. This takes more time but is potentially
+         a bit more secure.
+ 
+         Suggest setting Y during development and ironing out driver
+         issues etc. Suggest setting to N if you want faster writing.  
+
+         If unsure, say Y.
+
+config YAFFS_SHORT_NAMES_IN_RAM
+       bool "Cache short names in RAM"
+       depends on YAFFS_FS
+       default y
+       help
+         If this config is set, then short names are stored with the
+         yaffs_Object.  This costs an extra 16 bytes of RAM per object,
+         but makes look-ups faster.
+
+         If unsure, say Y.
diff -urN linux-2.6.21.1/fs/yaffs2/Makefile linux-2.6.21.1.new/fs/yaffs2/Makefile
--- linux-2.6.21.1/fs/yaffs2/Makefile   1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/Makefile       2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,11 @@
+#
+# Makefile for the linux YAFFS filesystem routines.
+#
+
+obj-$(CONFIG_YAFFS_FS) += yaffs.o
+
+yaffs-y := yaffs_ecc.o yaffs_fs.o yaffs_guts.o yaffs_checkptrw.o
+yaffs-y += yaffs_packedtags2.o yaffs_nand.o yaffs_qsort.o
+yaffs-y += yaffs_tagscompat.o yaffs_tagsvalidity.o
+yaffs-y += yaffs_mtdif1.o yaffs_packedtags1.o
+yaffs-y += yaffs_mtdif.o yaffs_mtdif2.o
diff -urN linux-2.6.21.1/fs/yaffs2/devextras.h linux-2.6.21.1.new/fs/yaffs2/devextras.h
--- linux-2.6.21.1/fs/yaffs2/devextras.h        1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/devextras.h    2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,264 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/*
+ * This file is just holds extra declarations used during development.
+ * Most of these are from kernel includes placed here so we can use them in 
+ * applications.
+ *
+ */
+
+#ifndef __EXTRAS_H__
+#define __EXTRAS_H__
+
+#if defined WIN32
+#define __inline__ __inline
+#define new newHack
+#endif
+
+#if !(defined __KERNEL__) || (defined WIN32)
+
+/* User space defines */
+
+typedef unsigned char __u8;
+typedef unsigned short __u16;
+typedef unsigned __u32;
+
+/*
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+#define prefetch(x) 1
+
+struct list_head {
+       struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+       struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+       (ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static __inline__ void __list_add(struct list_head *new,
+                                 struct list_head *prev,
+                                 struct list_head *next)
+{
+       next->prev = new;
+       new->next = next;
+       new->prev = prev;
+       prev->next = new;
+}
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+static __inline__ void list_add(struct list_head *new, struct list_head *head)
+{
+       __list_add(new, head, head->next);
+}
+
+/**
+ * list_add_tail - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ */
+static __inline__ void list_add_tail(struct list_head *new,
+                                    struct list_head *head)
+{
+       __list_add(new, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static __inline__ void __list_del(struct list_head *prev,
+                                 struct list_head *next)
+{
+       next->prev = prev;
+       prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is
+ * in an undefined state.
+ */
+static __inline__ void list_del(struct list_head *entry)
+{
+       __list_del(entry->prev, entry->next);
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry: the element to delete from the list.
+ */
+static __inline__ void list_del_init(struct list_head *entry)
+{
+       __list_del(entry->prev, entry->next);
+       INIT_LIST_HEAD(entry);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head: the list to test.
+ */
+static __inline__ int list_empty(struct list_head *head)
+{
+       return head->next == head;
+}
+
+/**
+ * list_splice - join two lists
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static __inline__ void list_splice(struct list_head *list,
+                                  struct list_head *head)
+{
+       struct list_head *first = list->next;
+
+       if (first != list) {
+               struct list_head *last = list->prev;
+               struct list_head *at = head->next;
+
+               first->prev = head;
+               head->next = first;
+
+               last->next = at;
+               at->prev = last;
+       }
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr:       the &struct list_head pointer.
+ * @type:      the type of the struct this is embedded in.
+ * @member:    the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+       ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
+
+/**
+ * list_for_each       -       iterate over a list
+ * @pos:       the &struct list_head to use as a loop counter.
+ * @head:      the head for your list.
+ */
+#define list_for_each(pos, head) \
+       for (pos = (head)->next, prefetch(pos->next); pos != (head); \
+               pos = pos->next, prefetch(pos->next))
+
+/**
+ * list_for_each_safe  -       iterate over a list safe against removal
+ *                              of list entry
+ * @pos:       the &struct list_head to use as a loop counter.
+ * @n:         another &struct list_head to use as temporary storage
+ * @head:      the head for your list.
+ */
+#define list_for_each_safe(pos, n, head) \
+       for (pos = (head)->next, n = pos->next; pos != (head); \
+               pos = n, n = pos->next)
+
+/*
+ * File types
+ */
+#define DT_UNKNOWN     0
+#define DT_FIFO                1
+#define DT_CHR         2
+#define DT_DIR         4
+#define DT_BLK         6
+#define DT_REG         8
+#define DT_LNK         10
+#define DT_SOCK                12
+#define DT_WHT         14
+
+#ifndef WIN32
+#include <sys/stat.h>
+#endif
+
+/*
+ * Attribute flags.  These should be or-ed together to figure out what
+ * has been changed!
+ */
+#define ATTR_MODE      1
+#define ATTR_UID       2
+#define ATTR_GID       4
+#define ATTR_SIZE      8
+#define ATTR_ATIME     16
+#define ATTR_MTIME     32
+#define ATTR_CTIME     64
+#define ATTR_ATIME_SET 128
+#define ATTR_MTIME_SET 256
+#define ATTR_FORCE     512     /* Not a change, but a change it */
+#define ATTR_ATTR_FLAG 1024
+
+struct iattr {
+       unsigned int ia_valid;
+       unsigned ia_mode;
+       unsigned ia_uid;
+       unsigned ia_gid;
+       unsigned ia_size;
+       unsigned ia_atime;
+       unsigned ia_mtime;
+       unsigned ia_ctime;
+       unsigned int ia_attr_flags;
+};
+
+#define KERN_DEBUG
+
+#else
+
+#ifndef WIN32
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#endif
+
+#endif
+
+#if defined WIN32
+#undef new
+#endif
+
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/moduleconfig.h linux-2.6.21.1.new/fs/yaffs2/moduleconfig.h
--- linux-2.6.21.1/fs/yaffs2/moduleconfig.h     1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/moduleconfig.h 2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,65 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Martin Fouts <Martin.Fouts@palmsource.com> 
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_CONFIG_H__
+#define __YAFFS_CONFIG_H__
+
+#ifdef YAFFS_OUT_OF_TREE
+
+/* DO NOT UNSET THESE THREE. YAFFS2 will not compile if you do. */
+#define CONFIG_YAFFS_FS
+#define CONFIG_YAFFS_YAFFS1
+#define CONFIG_YAFFS_YAFFS2
+
+/* These options are independent of each other.  Select those that matter. */
+
+/* Default: Not selected */
+/* Meaning: Yaffs does its own ECC, rather than using MTD ECC */
+//#define CONFIG_YAFFS_DOES_ECC
+
+/* Default: Not selected */
+/* Meaning: ECC byte order is 'wrong'.  Only meaningful if */
+/*          CONFIG_YAFFS_DOES_ECC is set */
+//#define CONFIG_YAFFS_ECC_WRONG_ORDER
+
+/* Default: Selected */
+/* Meaning: Disables testing whether chunks are erased before writing to them*/
+#define CONFIG_YAFFS_DISABLE_CHUNK_ERASED_CHECK
+
+/* Default: Selected */
+/* Meaning: Cache short names, taking more RAM, but faster look-ups */
+#define CONFIG_YAFFS_SHORT_NAMES_IN_RAM
+
+/* Default: 10 */
+/* Meaning: set the count of blocks to reserve for checkpointing */
+#define CONFIG_YAFFS_CHECKPOINT_RESERVED_BLOCKS 10
+
+/*
+Older-style on-NAND data format has a "pageStatus" byte to record
+chunk/page state.  This byte is zeroed when the page is discarded.
+Choose this option if you have existing on-NAND data in this format
+that you need to continue to support.  New data written also uses the
+older-style format.
+Note: Use of this option generally requires that MTD's oob layout be
+adjusted to use the older-style format.  See notes on tags formats and
+MTD versions.
+*/
+/* Default: Not selected */
+/* Meaning: Use older-style on-NAND data format with pageStatus byte */
+#define CONFIG_YAFFS_9BYTE_TAGS
+
+#endif /* YAFFS_OUT_OF_TREE */
+
+#endif /* __YAFFS_CONFIG_H__ */
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_checkptrw.c linux-2.6.21.1.new/fs/yaffs2/yaffs_checkptrw.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_checkptrw.c  1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_checkptrw.c      2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,404 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+const char *yaffs_checkptrw_c_version =
+    "$Id: yaffs_checkptrw.c,v 1.14 2007-05-15 20:07:40 charles Exp $";
+
+
+#include "yaffs_checkptrw.h"
+
+
+static int yaffs_CheckpointSpaceOk(yaffs_Device *dev)
+{
+
+       int blocksAvailable = dev->nErasedBlocks - dev->nReservedBlocks;
+       
+       T(YAFFS_TRACE_CHECKPOINT,
+               (TSTR("checkpt blocks available = %d" TENDSTR),
+               blocksAvailable));
+               
+       
+       return (blocksAvailable <= 0) ? 0 : 1;
+}
+
+
+static int yaffs_CheckpointErase(yaffs_Device *dev)
+{
+       
+       int i;
+       
+
+       if(!dev->eraseBlockInNAND)      
+               return 0;
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("checking blocks %d to %d"TENDSTR),
+               dev->internalStartBlock,dev->internalEndBlock));
+               
+       for(i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
+               yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,i);
+               if(bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT){
+                       T(YAFFS_TRACE_CHECKPOINT,(TSTR("erasing checkpt block %d"TENDSTR),i));
+                       if(dev->eraseBlockInNAND(dev,i- dev->blockOffset /* realign */)){
+                               bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
+                               dev->nErasedBlocks++;
+                               dev->nFreeChunks += dev->nChunksPerBlock;
+                       }
+                       else {
+                               dev->markNANDBlockBad(dev,i);
+                               bi->blockState = YAFFS_BLOCK_STATE_DEAD;
+                       }
+               }
+       }
+       
+       dev->blocksInCheckpoint = 0;
+       
+       return 1;
+}
+
+
+static void yaffs_CheckpointFindNextErasedBlock(yaffs_Device *dev)
+{
+       int  i;
+       int blocksAvailable = dev->nErasedBlocks - dev->nReservedBlocks;
+       T(YAFFS_TRACE_CHECKPOINT,
+               (TSTR("allocating checkpt block: erased %d reserved %d avail %d next %d "TENDSTR),
+               dev->nErasedBlocks,dev->nReservedBlocks,blocksAvailable,dev->checkpointNextBlock));
+               
+       if(dev->checkpointNextBlock >= 0 &&
+          dev->checkpointNextBlock <= dev->internalEndBlock &&
+          blocksAvailable > 0){
+       
+               for(i = dev->checkpointNextBlock; i <= dev->internalEndBlock; i++){
+                       yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,i);
+                       if(bi->blockState == YAFFS_BLOCK_STATE_EMPTY){
+                               dev->checkpointNextBlock = i + 1;
+                               dev->checkpointCurrentBlock = i;
+                               T(YAFFS_TRACE_CHECKPOINT,(TSTR("allocating checkpt block %d"TENDSTR),i));
+                               return;
+                       }
+               }
+       }
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("out of checkpt blocks"TENDSTR)));
+       
+       dev->checkpointNextBlock = -1;
+       dev->checkpointCurrentBlock = -1;
+}
+
+static void yaffs_CheckpointFindNextCheckpointBlock(yaffs_Device *dev)
+{
+       int  i;
+       yaffs_ExtendedTags tags;
+       
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("find next checkpt block: start:  blocks %d next %d" TENDSTR),
+               dev->blocksInCheckpoint, dev->checkpointNextBlock));
+               
+       if(dev->blocksInCheckpoint < dev->checkpointMaxBlocks) 
+               for(i = dev->checkpointNextBlock; i <= dev->internalEndBlock; i++){
+                       int chunk = i * dev->nChunksPerBlock;
+                       int realignedChunk = chunk - dev->chunkOffset;
+
+                       dev->readChunkWithTagsFromNAND(dev,realignedChunk,NULL,&tags);
+                       T(YAFFS_TRACE_CHECKPOINT,(TSTR("find next checkpt block: search: block %d oid %d seq %d eccr %d" TENDSTR), 
+                               i, tags.objectId,tags.sequenceNumber,tags.eccResult));
+                                                     
+                       if(tags.sequenceNumber == YAFFS_SEQUENCE_CHECKPOINT_DATA){
+                               /* Right kind of block */
+                               dev->checkpointNextBlock = tags.objectId;
+                               dev->checkpointCurrentBlock = i;
+                               dev->checkpointBlockList[dev->blocksInCheckpoint] = i;
+                               dev->blocksInCheckpoint++;
+                               T(YAFFS_TRACE_CHECKPOINT,(TSTR("found checkpt block %d"TENDSTR),i));
+                               return;
+                       }
+               }
+
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("found no more checkpt blocks"TENDSTR)));
+
+       dev->checkpointNextBlock = -1;
+       dev->checkpointCurrentBlock = -1;
+}
+
+
+int yaffs_CheckpointOpen(yaffs_Device *dev, int forWriting)
+{
+       
+       /* Got the functions we need? */
+       if (!dev->writeChunkWithTagsToNAND ||
+           !dev->readChunkWithTagsFromNAND ||
+           !dev->eraseBlockInNAND ||
+           !dev->markNANDBlockBad)
+               return 0;
+
+       if(forWriting && !yaffs_CheckpointSpaceOk(dev))
+               return 0;
+                       
+       if(!dev->checkpointBuffer)
+               dev->checkpointBuffer = YMALLOC_DMA(dev->nDataBytesPerChunk);
+       if(!dev->checkpointBuffer)
+               return 0;
+
+       
+       dev->checkpointPageSequence = 0;
+       
+       dev->checkpointOpenForWrite = forWriting;
+       
+       dev->checkpointByteCount = 0;
+       dev->checkpointSum = 0;
+       dev->checkpointXor = 0;
+       dev->checkpointCurrentBlock = -1;
+       dev->checkpointCurrentChunk = -1;
+       dev->checkpointNextBlock = dev->internalStartBlock;
+       
+       /* Erase all the blocks in the checkpoint area */
+       if(forWriting){
+               memset(dev->checkpointBuffer,0,dev->nDataBytesPerChunk);
+               dev->checkpointByteOffset = 0;
+               return yaffs_CheckpointErase(dev);
+               
+               
+       } else {
+               int i;
+               /* Set to a value that will kick off a read */
+               dev->checkpointByteOffset = dev->nDataBytesPerChunk;
+               /* A checkpoint block list of 1 checkpoint block per 16 block is (hopefully)
+                * going to be way more than we need */
+               dev->blocksInCheckpoint = 0;
+               dev->checkpointMaxBlocks = (dev->internalEndBlock - dev->internalStartBlock)/16 + 2;
+               dev->checkpointBlockList = YMALLOC(sizeof(int) * dev->checkpointMaxBlocks);
+               for(i = 0; i < dev->checkpointMaxBlocks; i++)
+                       dev->checkpointBlockList[i] = -1;
+       }
+       
+       return 1;
+}
+
+int yaffs_GetCheckpointSum(yaffs_Device *dev, __u32 *sum)
+{
+       __u32 compositeSum;
+       compositeSum =  (dev->checkpointSum << 8) | (dev->checkpointXor & 0xFF);
+       *sum = compositeSum;
+       return 1;
+}
+
+static int yaffs_CheckpointFlushBuffer(yaffs_Device *dev)
+{
+
+       int chunk;
+       int realignedChunk;
+
+       yaffs_ExtendedTags tags;
+       
+       if(dev->checkpointCurrentBlock < 0){
+               yaffs_CheckpointFindNextErasedBlock(dev);
+               dev->checkpointCurrentChunk = 0;
+       }
+       
+       if(dev->checkpointCurrentBlock < 0)
+               return 0;
+       
+       tags.chunkDeleted = 0;
+       tags.objectId = dev->checkpointNextBlock; /* Hint to next place to look */
+       tags.chunkId = dev->checkpointPageSequence + 1;
+       tags.sequenceNumber =  YAFFS_SEQUENCE_CHECKPOINT_DATA;
+       tags.byteCount = dev->nDataBytesPerChunk;
+       if(dev->checkpointCurrentChunk == 0){
+               /* First chunk we write for the block? Set block state to
+                  checkpoint */
+               yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,dev->checkpointCurrentBlock);
+               bi->blockState = YAFFS_BLOCK_STATE_CHECKPOINT;
+               dev->blocksInCheckpoint++;
+       }
+       
+       chunk = dev->checkpointCurrentBlock * dev->nChunksPerBlock + dev->checkpointCurrentChunk;
+
+       
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("checkpoint wite buffer nand %d(%d:%d) objid %d chId %d" TENDSTR),
+               chunk, dev->checkpointCurrentBlock, dev->checkpointCurrentChunk,tags.objectId,tags.chunkId)); 
+       
+       realignedChunk = chunk - dev->chunkOffset;
+       
+       dev->writeChunkWithTagsToNAND(dev,realignedChunk,dev->checkpointBuffer,&tags);
+       dev->checkpointByteOffset = 0;
+       dev->checkpointPageSequence++;     
+       dev->checkpointCurrentChunk++;
+       if(dev->checkpointCurrentChunk >= dev->nChunksPerBlock){
+               dev->checkpointCurrentChunk = 0;
+               dev->checkpointCurrentBlock = -1;
+       }
+       memset(dev->checkpointBuffer,0,dev->nDataBytesPerChunk);
+       
+       return 1;
+}
+
+
+int yaffs_CheckpointWrite(yaffs_Device *dev,const void *data, int nBytes)
+{
+       int i=0;
+       int ok = 1;
+
+       
+       __u8 * dataBytes = (__u8 *)data;
+       
+       
+
+       if(!dev->checkpointBuffer)
+               return 0;
+               
+       if(!dev->checkpointOpenForWrite)
+               return -1;
+
+       while(i < nBytes && ok) {
+               
+
+               
+               dev->checkpointBuffer[dev->checkpointByteOffset] = *dataBytes ;
+               dev->checkpointSum += *dataBytes;
+               dev->checkpointXor ^= *dataBytes;
+                
+               dev->checkpointByteOffset++;
+               i++;
+               dataBytes++;
+               dev->checkpointByteCount++;
+               
+               
+               if(dev->checkpointByteOffset < 0 ||
+                  dev->checkpointByteOffset >= dev->nDataBytesPerChunk) 
+                       ok = yaffs_CheckpointFlushBuffer(dev);
+
+       }
+       
+       return  i;
+}
+
+int yaffs_CheckpointRead(yaffs_Device *dev, void *data, int nBytes)
+{
+       int i=0;
+       int ok = 1;
+       yaffs_ExtendedTags tags;
+
+       
+       int chunk;
+       int realignedChunk;
+
+       __u8 *dataBytes = (__u8 *)data;
+               
+       if(!dev->checkpointBuffer)
+               return 0;
+
+       if(dev->checkpointOpenForWrite)
+               return -1;
+
+       while(i < nBytes && ok) {
+       
+       
+               if(dev->checkpointByteOffset < 0 ||
+                  dev->checkpointByteOffset >= dev->nDataBytesPerChunk) {
+                  
+                       if(dev->checkpointCurrentBlock < 0){
+                               yaffs_CheckpointFindNextCheckpointBlock(dev);
+                               dev->checkpointCurrentChunk = 0;
+                       }
+                       
+                       if(dev->checkpointCurrentBlock < 0)
+                               ok = 0;
+                       else {
+                       
+                               chunk = dev->checkpointCurrentBlock * dev->nChunksPerBlock + 
+                                         dev->checkpointCurrentChunk;
+
+                               realignedChunk = chunk - dev->chunkOffset;
+
+                               /* read in the next chunk */
+                               /* printf("read checkpoint page %d\n",dev->checkpointPage); */
+                               dev->readChunkWithTagsFromNAND(dev, realignedChunk, 
+                                                              dev->checkpointBuffer,
+                                                             &tags);
+                                                     
+                               if(tags.chunkId != (dev->checkpointPageSequence + 1) ||
+                                  tags.sequenceNumber != YAFFS_SEQUENCE_CHECKPOINT_DATA)
+                                  ok = 0;
+
+                               dev->checkpointByteOffset = 0;
+                               dev->checkpointPageSequence++;
+                               dev->checkpointCurrentChunk++;
+                       
+                               if(dev->checkpointCurrentChunk >= dev->nChunksPerBlock)
+                                       dev->checkpointCurrentBlock = -1;
+                       }
+               }
+               
+               if(ok){
+                       *dataBytes = dev->checkpointBuffer[dev->checkpointByteOffset];
+                       dev->checkpointSum += *dataBytes;
+                       dev->checkpointXor ^= *dataBytes;
+                       dev->checkpointByteOffset++;
+                       i++;
+                       dataBytes++;
+                       dev->checkpointByteCount++;
+               }
+       }
+       
+       return  i;
+}
+
+int yaffs_CheckpointClose(yaffs_Device *dev)
+{
+
+       if(dev->checkpointOpenForWrite){        
+               if(dev->checkpointByteOffset != 0)
+                       yaffs_CheckpointFlushBuffer(dev);
+       } else {
+               int i;
+               for(i = 0; i < dev->blocksInCheckpoint && dev->checkpointBlockList[i] >= 0; i++){
+                       yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,dev->checkpointBlockList[i]);
+                       if(bi->blockState == YAFFS_BLOCK_STATE_EMPTY)
+                               bi->blockState = YAFFS_BLOCK_STATE_CHECKPOINT;
+                       else {
+                               // Todo this looks odd...
+                       }
+               }
+               YFREE(dev->checkpointBlockList);
+               dev->checkpointBlockList = NULL;
+       }
+
+       dev->nFreeChunks -= dev->blocksInCheckpoint * dev->nChunksPerBlock;
+       dev->nErasedBlocks -= dev->blocksInCheckpoint;
+
+               
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("checkpoint byte count %d" TENDSTR),
+                       dev->checkpointByteCount));
+                       
+       if(dev->checkpointBuffer){
+               /* free the buffer */   
+               YFREE(dev->checkpointBuffer);
+               dev->checkpointBuffer = NULL;
+               return 1;
+       }
+       else
+               return 0;
+       
+}
+
+int yaffs_CheckpointInvalidateStream(yaffs_Device *dev)
+{
+       /* Erase the first checksum block */
+
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("checkpoint invalidate"TENDSTR)));
+
+       if(!yaffs_CheckpointSpaceOk(dev))
+               return 0;
+
+       return yaffs_CheckpointErase(dev);
+}
+
+
+
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_checkptrw.h linux-2.6.21.1.new/fs/yaffs2/yaffs_checkptrw.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_checkptrw.h  1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_checkptrw.h      2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,35 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_CHECKPTRW_H__
+#define __YAFFS_CHECKPTRW_H__
+
+#include "yaffs_guts.h"
+
+int yaffs_CheckpointOpen(yaffs_Device *dev, int forWriting);
+
+int yaffs_CheckpointWrite(yaffs_Device *dev,const void *data, int nBytes);
+
+int yaffs_CheckpointRead(yaffs_Device *dev,void *data, int nBytes);
+
+int yaffs_GetCheckpointSum(yaffs_Device *dev, __u32 *sum);
+
+int yaffs_CheckpointClose(yaffs_Device *dev);
+
+int yaffs_CheckpointInvalidateStream(yaffs_Device *dev);
+
+
+#endif
+
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_ecc.c linux-2.6.21.1.new/fs/yaffs2/yaffs_ecc.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_ecc.c        1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_ecc.c    2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,331 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This code implements the ECC algorithm used in SmartMedia.
+ *
+ * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes. 
+ * The two unused bit are set to 1.
+ * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC 
+ * blocks are used on a 512-byte NAND page.
+ *
+ */
+
+/* Table generated by gen-ecc.c
+ * Using a table means we do not have to calculate p1..p4 and p1'..p4'
+ * for each byte of data. These are instead provided in a table in bits7..2.
+ * Bit 0 of each entry indicates whether the entry has an odd or even parity, and therefore
+ * this bytes influence on the line parity.
+ */
+
+const char *yaffs_ecc_c_version =
+    "$Id: yaffs_ecc.c,v 1.9 2007-02-14 01:09:06 wookey Exp $";
+
+#include "yportenv.h"
+
+#include "yaffs_ecc.h"
+
+static const unsigned char column_parity_table[] = {
+       0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+       0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+       0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+       0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+       0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+       0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+       0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+       0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+       0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+       0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+       0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+       0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+       0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+       0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+       0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+       0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+       0xa9, 0xfc, 0xf0, 0xa5, 0xcc, 0x99, 0x95, 0xc0,
+       0xc0, 0x95, 0x99, 0xcc, 0xa5, 0xf0, 0xfc, 0xa9,
+       0x3c, 0x69, 0x65, 0x30, 0x59, 0x0c, 0x00, 0x55,
+       0x55, 0x00, 0x0c, 0x59, 0x30, 0x65, 0x69, 0x3c,
+       0x30, 0x65, 0x69, 0x3c, 0x55, 0x00, 0x0c, 0x59,
+       0x59, 0x0c, 0x00, 0x55, 0x3c, 0x69, 0x65, 0x30,
+       0xa5, 0xf0, 0xfc, 0xa9, 0xc0, 0x95, 0x99, 0xcc,
+       0xcc, 0x99, 0x95, 0xc0, 0xa9, 0xfc, 0xf0, 0xa5,
+       0x0c, 0x59, 0x55, 0x00, 0x69, 0x3c, 0x30, 0x65,
+       0x65, 0x30, 0x3c, 0x69, 0x00, 0x55, 0x59, 0x0c,
+       0x99, 0xcc, 0xc0, 0x95, 0xfc, 0xa9, 0xa5, 0xf0,
+       0xf0, 0xa5, 0xa9, 0xfc, 0x95, 0xc0, 0xcc, 0x99,
+       0x95, 0xc0, 0xcc, 0x99, 0xf0, 0xa5, 0xa9, 0xfc,
+       0xfc, 0xa9, 0xa5, 0xf0, 0x99, 0xcc, 0xc0, 0x95,
+       0x00, 0x55, 0x59, 0x0c, 0x65, 0x30, 0x3c, 0x69,
+       0x69, 0x3c, 0x30, 0x65, 0x0c, 0x59, 0x55, 0x00,
+};
+
+/* Count the bits in an unsigned char or a U32 */
+
+static int yaffs_CountBits(unsigned char x)
+{
+       int r = 0;
+       while (x) {
+               if (x & 1)
+                       r++;
+               x >>= 1;
+       }
+       return r;
+}
+
+static int yaffs_CountBits32(unsigned x)
+{
+       int r = 0;
+       while (x) {
+               if (x & 1)
+                       r++;
+               x >>= 1;
+       }
+       return r;
+}
+
+/* Calculate the ECC for a 256-byte block of data */
+void yaffs_ECCCalculate(const unsigned char *data, unsigned char *ecc)
+{
+       unsigned int i;
+
+       unsigned char col_parity = 0;
+       unsigned char line_parity = 0;
+       unsigned char line_parity_prime = 0;
+       unsigned char t;
+       unsigned char b;
+
+       for (i = 0; i < 256; i++) {
+               b = column_parity_table[*data++];
+               col_parity ^= b;
+
+               if (b & 0x01)   // odd number of bits in the byte
+               {
+                       line_parity ^= i;
+                       line_parity_prime ^= ~i;
+               }
+
+       }
+
+       ecc[2] = (~col_parity) | 0x03;
+
+       t = 0;
+       if (line_parity & 0x80)
+               t |= 0x80;
+       if (line_parity_prime & 0x80)
+               t |= 0x40;
+       if (line_parity & 0x40)
+               t |= 0x20;
+       if (line_parity_prime & 0x40)
+               t |= 0x10;
+       if (line_parity & 0x20)
+               t |= 0x08;
+       if (line_parity_prime & 0x20)
+               t |= 0x04;
+       if (line_parity & 0x10)
+               t |= 0x02;
+       if (line_parity_prime & 0x10)
+               t |= 0x01;
+       ecc[1] = ~t;
+
+       t = 0;
+       if (line_parity & 0x08)
+               t |= 0x80;
+       if (line_parity_prime & 0x08)
+               t |= 0x40;
+       if (line_parity & 0x04)
+               t |= 0x20;
+       if (line_parity_prime & 0x04)
+               t |= 0x10;
+       if (line_parity & 0x02)
+               t |= 0x08;
+       if (line_parity_prime & 0x02)
+               t |= 0x04;
+       if (line_parity & 0x01)
+               t |= 0x02;
+       if (line_parity_prime & 0x01)
+               t |= 0x01;
+       ecc[0] = ~t;
+
+#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
+       // Swap the bytes into the wrong order
+       t = ecc[0];
+       ecc[0] = ecc[1];
+       ecc[1] = t;
+#endif
+}
+
+
+/* Correct the ECC on a 256 byte block of data */
+
+int yaffs_ECCCorrect(unsigned char *data, unsigned char *read_ecc,
+                    const unsigned char *test_ecc)
+{
+       unsigned char d0, d1, d2;       /* deltas */
+
+       d0 = read_ecc[0] ^ test_ecc[0];
+       d1 = read_ecc[1] ^ test_ecc[1];
+       d2 = read_ecc[2] ^ test_ecc[2];
+
+       if ((d0 | d1 | d2) == 0)
+               return 0; /* no error */
+
+       if (((d0 ^ (d0 >> 1)) & 0x55) == 0x55 &&
+           ((d1 ^ (d1 >> 1)) & 0x55) == 0x55 &&
+           ((d2 ^ (d2 >> 1)) & 0x54) == 0x54) {
+               /* Single bit (recoverable) error in data */
+
+               unsigned byte;
+               unsigned bit;
+
+#ifdef CONFIG_YAFFS_ECC_WRONG_ORDER
+               // swap the bytes to correct for the wrong order
+               unsigned char t;
+
+               t = d0;
+               d0 = d1;
+               d1 = t;
+#endif
+
+               bit = byte = 0;
+
+               if (d1 & 0x80)
+                       byte |= 0x80;
+               if (d1 & 0x20)
+                       byte |= 0x40;
+               if (d1 & 0x08)
+                       byte |= 0x20;
+               if (d1 & 0x02)
+                       byte |= 0x10;
+               if (d0 & 0x80)
+                       byte |= 0x08;
+               if (d0 & 0x20)
+                       byte |= 0x04;
+               if (d0 & 0x08)
+                       byte |= 0x02;
+               if (d0 & 0x02)
+                       byte |= 0x01;
+
+               if (d2 & 0x80)
+                       bit |= 0x04;
+               if (d2 & 0x20)
+                       bit |= 0x02;
+               if (d2 & 0x08)
+                       bit |= 0x01;
+
+               data[byte] ^= (1 << bit);
+
+               return 1; /* Corrected the error */
+       }
+
+       if ((yaffs_CountBits(d0) + 
+            yaffs_CountBits(d1) + 
+            yaffs_CountBits(d2)) ==  1) {
+               /* Reccoverable error in ecc */
+
+               read_ecc[0] = test_ecc[0];
+               read_ecc[1] = test_ecc[1];
+               read_ecc[2] = test_ecc[2];
+
+               return 1; /* Corrected the error */
+       }
+       
+       /* Unrecoverable error */
+
+       return -1;
+
+}
+
+
+/*
+ * ECCxxxOther does ECC calcs on arbitrary n bytes of data
+ */
+void yaffs_ECCCalculateOther(const unsigned char *data, unsigned nBytes,
+                            yaffs_ECCOther * eccOther)
+{
+       unsigned int i;
+
+       unsigned char col_parity = 0;
+       unsigned line_parity = 0;
+       unsigned line_parity_prime = 0;
+       unsigned char b;
+
+       for (i = 0; i < nBytes; i++) {
+               b = column_parity_table[*data++];
+               col_parity ^= b;
+
+               if (b & 0x01)    {
+                       /* odd number of bits in the byte */
+                       line_parity ^= i;
+                       line_parity_prime ^= ~i;
+               }
+
+       }
+
+       eccOther->colParity = (col_parity >> 2) & 0x3f;
+       eccOther->lineParity = line_parity;
+       eccOther->lineParityPrime = line_parity_prime;
+}
+
+int yaffs_ECCCorrectOther(unsigned char *data, unsigned nBytes,
+                         yaffs_ECCOther * read_ecc,
+                         const yaffs_ECCOther * test_ecc)
+{
+       unsigned char cDelta;   /* column parity delta */
+       unsigned lDelta;        /* line parity delta */
+       unsigned lDeltaPrime;   /* line parity delta */
+       unsigned bit;
+
+       cDelta = read_ecc->colParity ^ test_ecc->colParity;
+       lDelta = read_ecc->lineParity ^ test_ecc->lineParity;
+       lDeltaPrime = read_ecc->lineParityPrime ^ test_ecc->lineParityPrime;
+
+       if ((cDelta | lDelta | lDeltaPrime) == 0)
+               return 0; /* no error */
+
+       if (lDelta == ~lDeltaPrime && 
+           (((cDelta ^ (cDelta >> 1)) & 0x15) == 0x15))
+       {
+               /* Single bit (recoverable) error in data */
+
+               bit = 0;
+
+               if (cDelta & 0x20)
+                       bit |= 0x04;
+               if (cDelta & 0x08)
+                       bit |= 0x02;
+               if (cDelta & 0x02)
+                       bit |= 0x01;
+
+               if(lDelta >= nBytes)
+                       return -1;
+                       
+               data[lDelta] ^= (1 << bit);
+
+               return 1; /* corrected */
+       }
+
+       if ((yaffs_CountBits32(lDelta) + yaffs_CountBits32(lDeltaPrime) +
+            yaffs_CountBits(cDelta)) == 1) {
+               /* Reccoverable error in ecc */
+
+               *read_ecc = *test_ecc;
+               return 1; /* corrected */
+       }
+
+       /* Unrecoverable error */
+
+       return -1;
+
+}
+
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_ecc.h linux-2.6.21.1.new/fs/yaffs2/yaffs_ecc.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_ecc.h        1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_ecc.h    2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,44 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+ /*
+  * This code implements the ECC algorithm used in SmartMedia.
+  *
+  * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes. 
+  * The two unused bit are set to 1.
+  * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC 
+  * blocks are used on a 512-byte NAND page.
+  *
+  */
+
+#ifndef __YAFFS_ECC_H__
+#define __YAFFS_ECC_H__
+
+typedef struct {
+       unsigned char colParity;
+       unsigned lineParity;
+       unsigned lineParityPrime;
+} yaffs_ECCOther;
+
+void yaffs_ECCCalculate(const unsigned char *data, unsigned char *ecc);
+int yaffs_ECCCorrect(unsigned char *data, unsigned char *read_ecc,
+                    const unsigned char *test_ecc);
+
+void yaffs_ECCCalculateOther(const unsigned char *data, unsigned nBytes,
+                            yaffs_ECCOther * ecc);
+int yaffs_ECCCorrectOther(unsigned char *data, unsigned nBytes,
+                         yaffs_ECCOther * read_ecc,
+                         const yaffs_ECCOther * test_ecc);
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_fs.c linux-2.6.21.1.new/fs/yaffs2/yaffs_fs.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_fs.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_fs.c     2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,2278 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ * Acknowledgements:
+ * Luc van OostenRyck for numerous patches.
+ * Nick Bane for numerous patches.
+ * Nick Bane for 2.5/2.6 integration.
+ * Andras Toth for mknod rdev issue.
+ * Michael Fischer for finding the problem with inode inconsistency.
+ * Some code bodily lifted from JFFS
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ *
+ * This is the file system front-end to YAFFS that hooks it up to
+ * the VFS.
+ *
+ * Special notes: 
+ * >> 2.4: sb->u.generic_sbp points to the yaffs_Device associated with
+ *         this superblock
+ * >> 2.6: sb->s_fs_info  points to the yaffs_Device associated with this
+ *         superblock
+ * >> inode->u.generic_ip points to the associated yaffs_Object.
+ */
+
+const char *yaffs_fs_c_version =
+    "$Id: yaffs_fs.c,v 1.60 2007-05-15 20:07:40 charles Exp $";
+extern const char *yaffs_guts_c_version;
+
+#include <linux/version.h>
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
+#include <linux/config.h>
+#endif
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/smp_lock.h>
+#include <linux/pagemap.h>
+#include <linux/mtd/mtd.h>
+#include <linux/interrupt.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+
+#include <linux/statfs.h>      /* Added NCB 15-8-2003 */
+#include <asm/statfs.h>
+#define UnlockPage(p) unlock_page(p)
+#define Page_Uptodate(page)    test_bit(PG_uptodate, &(page)->flags)
+
+/* FIXME: use sb->s_id instead ? */
+#define yaffs_devname(sb, buf) bdevname(sb->s_bdev, buf)
+
+#else
+
+#include <linux/locks.h>
+#define        BDEVNAME_SIZE           0
+#define        yaffs_devname(sb, buf)  kdevname(sb->s_dev)
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
+/* added NCB 26/5/2006 for 2.4.25-vrs2-tcl1 kernel */
+#define __user
+#endif
+
+#endif
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+#define WRITE_SIZE_STR "writesize"
+#define WRITE_SIZE(mtd) (mtd)->writesize
+#else
+#define WRITE_SIZE_STR "oobblock"
+#define WRITE_SIZE(mtd) (mtd)->oobblock
+#endif
+
+#include <asm/uaccess.h>
+
+#include "yportenv.h"
+#include "yaffs_guts.h"
+
+#include <linux/mtd/mtd.h>
+#include "yaffs_mtdif.h"
+#include "yaffs_mtdif1.h"
+#include "yaffs_mtdif2.h"
+
+unsigned int yaffs_traceMask = YAFFS_TRACE_BAD_BLOCKS;
+unsigned int yaffs_wr_attempts = YAFFS_WR_ATTEMPTS;
+
+/* Module Parameters */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+module_param(yaffs_traceMask,uint,0644);
+module_param(yaffs_wr_attempts,uint,0644);
+#else
+MODULE_PARM(yaffs_traceMask,"i");
+MODULE_PARM(yaffs_wr_attempts,"i");
+#endif
+
+/*#define T(x) printk x */
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18))
+#define yaffs_InodeToObjectLV(iptr) (iptr)->i_private
+#else
+#define yaffs_InodeToObjectLV(iptr) (iptr)->u.generic_ip
+#endif
+
+#define yaffs_InodeToObject(iptr) ((yaffs_Object *)(yaffs_InodeToObjectLV(iptr)))
+#define yaffs_DentryToObject(dptr) yaffs_InodeToObject((dptr)->d_inode)
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+#define yaffs_SuperToDevice(sb)        ((yaffs_Device *)sb->s_fs_info)
+#else
+#define yaffs_SuperToDevice(sb)        ((yaffs_Device *)sb->u.generic_sbp)
+#endif
+
+static void yaffs_put_super(struct super_block *sb);
+
+static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
+                               loff_t * pos);
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static int yaffs_file_flush(struct file *file, fl_owner_t id);
+#else
+static int yaffs_file_flush(struct file *file);
+#endif
+
+static int yaffs_sync_object(struct file *file, struct dentry *dentry,
+                            int datasync);
+
+static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir);
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode,
+                       struct nameidata *n);
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry,
+                                  struct nameidata *n);
+#else
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode);
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry);
+#endif
+static int yaffs_link(struct dentry *old_dentry, struct inode *dir,
+                     struct dentry *dentry);
+static int yaffs_unlink(struct inode *dir, struct dentry *dentry);
+static int yaffs_symlink(struct inode *dir, struct dentry *dentry,
+                        const char *symname);
+static int yaffs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+                      dev_t dev);
+#else
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+                      int dev);
+#endif
+static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
+                       struct inode *new_dir, struct dentry *new_dentry);
+static int yaffs_setattr(struct dentry *dentry, struct iattr *attr);
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static int yaffs_sync_fs(struct super_block *sb, int wait);
+static void yaffs_write_super(struct super_block *sb);
+#else
+static int yaffs_sync_fs(struct super_block *sb);
+static int yaffs_write_super(struct super_block *sb);
+#endif
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static int yaffs_statfs(struct dentry *dentry, struct kstatfs *buf);
+#elif (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs_statfs(struct super_block *sb, struct kstatfs *buf);
+#else
+static int yaffs_statfs(struct super_block *sb, struct statfs *buf);
+#endif
+static void yaffs_read_inode(struct inode *inode);
+
+static void yaffs_put_inode(struct inode *inode);
+static void yaffs_delete_inode(struct inode *);
+static void yaffs_clear_inode(struct inode *);
+
+static int yaffs_readpage(struct file *file, struct page *page);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs_writepage(struct page *page, struct writeback_control *wbc);
+#else
+static int yaffs_writepage(struct page *page);
+#endif
+static int yaffs_prepare_write(struct file *f, struct page *pg,
+                              unsigned offset, unsigned to);
+static int yaffs_commit_write(struct file *f, struct page *pg, unsigned offset,
+                             unsigned to);
+
+static int yaffs_readlink(struct dentry *dentry, char __user * buffer,
+                         int buflen);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,13))
+static void *yaffs_follow_link(struct dentry *dentry, struct nameidata *nd);
+#else
+static int yaffs_follow_link(struct dentry *dentry, struct nameidata *nd);
+#endif
+
+static struct address_space_operations yaffs_file_address_operations = {
+       .readpage = yaffs_readpage,
+       .writepage = yaffs_writepage,
+       .prepare_write = yaffs_prepare_write,
+       .commit_write = yaffs_commit_write,
+};
+
+static struct file_operations yaffs_file_operations = {
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18))
+       .read = do_sync_read,
+       .write = do_sync_write,
+       .aio_read = generic_file_aio_read,
+       .aio_write = generic_file_aio_write,
+#else
+       .read = generic_file_read,
+       .write = generic_file_write,
+#endif
+       .mmap = generic_file_mmap,
+       .flush = yaffs_file_flush,
+       .fsync = yaffs_sync_object,
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+       .sendfile = generic_file_sendfile,
+#endif
+
+};
+
+static struct inode_operations yaffs_file_inode_operations = {
+       .setattr = yaffs_setattr,
+};
+
+static struct inode_operations yaffs_symlink_inode_operations = {
+       .readlink = yaffs_readlink,
+       .follow_link = yaffs_follow_link,
+       .setattr = yaffs_setattr,
+};
+
+static struct inode_operations yaffs_dir_inode_operations = {
+       .create = yaffs_create,
+       .lookup = yaffs_lookup,
+       .link = yaffs_link,
+       .unlink = yaffs_unlink,
+       .symlink = yaffs_symlink,
+       .mkdir = yaffs_mkdir,
+       .rmdir = yaffs_unlink,
+       .mknod = yaffs_mknod,
+       .rename = yaffs_rename,
+       .setattr = yaffs_setattr,
+};
+
+static struct file_operations yaffs_dir_operations = {
+       .read = generic_read_dir,
+       .readdir = yaffs_readdir,
+       .fsync = yaffs_sync_object,
+};
+
+static struct super_operations yaffs_super_ops = {
+       .statfs = yaffs_statfs,
+       .read_inode = yaffs_read_inode,
+       .put_inode = yaffs_put_inode,
+       .put_super = yaffs_put_super,
+       .delete_inode = yaffs_delete_inode,
+       .clear_inode = yaffs_clear_inode,
+       .sync_fs = yaffs_sync_fs,
+       .write_super = yaffs_write_super,
+};
+
+static void yaffs_GrossLock(yaffs_Device * dev)
+{
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs locking\n"));
+
+       down(&dev->grossLock);
+}
+
+static void yaffs_GrossUnlock(yaffs_Device * dev)
+{
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs unlocking\n"));
+       up(&dev->grossLock);
+
+}
+
+static int yaffs_readlink(struct dentry *dentry, char __user * buffer,
+                         int buflen)
+{
+       unsigned char *alias;
+       int ret;
+
+       yaffs_Device *dev = yaffs_DentryToObject(dentry)->myDev;
+
+       yaffs_GrossLock(dev);
+
+       alias = yaffs_GetSymlinkAlias(yaffs_DentryToObject(dentry));
+
+       yaffs_GrossUnlock(dev);
+
+       if (!alias)
+               return -ENOMEM;
+
+       ret = vfs_readlink(dentry, buffer, buflen, alias);
+       kfree(alias);
+       return ret;
+}
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,13))
+static void *yaffs_follow_link(struct dentry *dentry, struct nameidata *nd)
+#else
+static int yaffs_follow_link(struct dentry *dentry, struct nameidata *nd)
+#endif
+{
+       unsigned char *alias;
+       int ret;
+       yaffs_Device *dev = yaffs_DentryToObject(dentry)->myDev;
+
+       yaffs_GrossLock(dev);
+
+       alias = yaffs_GetSymlinkAlias(yaffs_DentryToObject(dentry));
+
+       yaffs_GrossUnlock(dev);
+
+       if (!alias)
+        {
+               ret = -ENOMEM;
+               goto out;
+        }
+
+       ret = vfs_follow_link(nd, alias);
+       kfree(alias);
+out:
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,13))
+       return ERR_PTR (ret);
+#else
+       return ret;
+#endif
+}
+
+struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,
+                             yaffs_Object * obj);
+
+/*
+ * Lookup is used to find objects in the fs
+ */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry,
+                                  struct nameidata *n)
+#else
+static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry)
+#endif
+{
+       yaffs_Object *obj;
+       struct inode *inode = NULL;     /* NCB 2.5/2.6 needs NULL here */
+
+       yaffs_Device *dev = yaffs_InodeToObject(dir)->myDev;
+
+       yaffs_GrossLock(dev);
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_lookup for %d:%s\n",
+          yaffs_InodeToObject(dir)->objectId, dentry->d_name.name));
+
+       obj =
+           yaffs_FindObjectByName(yaffs_InodeToObject(dir),
+                                  dentry->d_name.name);
+
+       obj = yaffs_GetEquivalentObject(obj);   /* in case it was a hardlink */
+       
+       /* Can't hold gross lock when calling yaffs_get_inode() */
+       yaffs_GrossUnlock(dev);
+
+       if (obj) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_lookup found %d\n", obj->objectId));
+
+               inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
+
+               if (inode) {
+                       T(YAFFS_TRACE_OS,
+                         (KERN_DEBUG "yaffs_loookup dentry \n"));
+/* #if 0 asserted by NCB for 2.5/6 compatability - falls through to
+ * d_add even if NULL inode */
+#if 0
+                       /*dget(dentry); // try to solve directory bug */
+                       d_add(dentry, inode);
+
+                       /* return dentry; */
+                       return NULL;
+#endif
+               }
+
+       } else {
+               T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_lookup not found\n"));
+
+       }
+
+/* added NCB for 2.5/6 compatability - forces add even if inode is
+ * NULL which creates dentry hash */
+       d_add(dentry, inode);
+
+       return NULL;
+       /*      return (ERR_PTR(-EIO)); */
+
+}
+
+/* For now put inode is just for debugging
+ * Put inode is called when the inode **structure** is put.
+ */
+static void yaffs_put_inode(struct inode *inode)
+{
+       T(YAFFS_TRACE_OS,
+         ("yaffs_put_inode: ino %d, count %d\n", (int)inode->i_ino,
+          atomic_read(&inode->i_count)));
+
+}
+
+/* clear is called to tell the fs to release any per-inode data it holds */
+static void yaffs_clear_inode(struct inode *inode)
+{
+       yaffs_Object *obj;
+       yaffs_Device *dev;
+
+       obj = yaffs_InodeToObject(inode);
+
+       T(YAFFS_TRACE_OS,
+         ("yaffs_clear_inode: ino %d, count %d %s\n", (int)inode->i_ino,
+          atomic_read(&inode->i_count),
+          obj ? "object exists" : "null object"));
+
+       if (obj) {
+               dev = obj->myDev;
+               yaffs_GrossLock(dev);
+
+               /* Clear the association between the inode and
+                * the yaffs_Object.
+                */
+               obj->myInode = NULL;
+               yaffs_InodeToObjectLV(inode) = NULL;
+
+               /* If the object freeing was deferred, then the real
+                * free happens now.
+                * This should fix the inode inconsistency problem.
+                */
+
+               yaffs_HandleDeferedFree(obj);
+
+               yaffs_GrossUnlock(dev);
+       }
+
+}
+
+/* delete is called when the link count is zero and the inode
+ * is put (ie. nobody wants to know about it anymore, time to
+ * delete the file).
+ * NB Must call clear_inode()
+ */
+static void yaffs_delete_inode(struct inode *inode)
+{
+       yaffs_Object *obj = yaffs_InodeToObject(inode);
+       yaffs_Device *dev;
+
+       T(YAFFS_TRACE_OS,
+         ("yaffs_delete_inode: ino %d, count %d %s\n", (int)inode->i_ino,
+          atomic_read(&inode->i_count),
+          obj ? "object exists" : "null object"));
+
+       if (obj) {
+               dev = obj->myDev;
+               yaffs_GrossLock(dev);
+               yaffs_DeleteFile(obj);
+               yaffs_GrossUnlock(dev);
+       }
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,13))
+        truncate_inode_pages (&inode->i_data, 0);
+#endif
+       clear_inode(inode);
+}
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static int yaffs_file_flush(struct file *file, fl_owner_t id)
+#else
+static int yaffs_file_flush(struct file *file)
+#endif
+{
+       yaffs_Object *obj = yaffs_DentryToObject(file->f_dentry);
+
+       yaffs_Device *dev = obj->myDev;
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_file_flush object %d (%s)\n", obj->objectId,
+          obj->dirty ? "dirty" : "clean"));
+
+       yaffs_GrossLock(dev);
+
+       yaffs_FlushFile(obj, 1);
+
+       yaffs_GrossUnlock(dev);
+
+       return 0;
+}
+
+static int yaffs_readpage_nolock(struct file *f, struct page *pg)
+{
+       /* Lifted from jffs2 */
+
+       yaffs_Object *obj;
+       unsigned char *pg_buf;
+       int ret;
+
+       yaffs_Device *dev;
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_readpage at %08x, size %08x\n",
+                          (unsigned)(pg->index << PAGE_CACHE_SHIFT),
+                          (unsigned)PAGE_CACHE_SIZE));
+
+       obj = yaffs_DentryToObject(f->f_dentry);
+
+       dev = obj->myDev;
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+       BUG_ON(!PageLocked(pg));
+#else
+       if (!PageLocked(pg))
+               PAGE_BUG(pg);
+#endif
+
+       pg_buf = kmap(pg);
+       /* FIXME: Can kmap fail? */
+
+       yaffs_GrossLock(dev);
+
+       ret =
+           yaffs_ReadDataFromFile(obj, pg_buf, pg->index << PAGE_CACHE_SHIFT,
+                                  PAGE_CACHE_SIZE);
+
+       yaffs_GrossUnlock(dev);
+
+       if (ret >= 0)
+               ret = 0;
+
+       if (ret) {
+               ClearPageUptodate(pg);
+               SetPageError(pg);
+       } else {
+               SetPageUptodate(pg);
+               ClearPageError(pg);
+       }
+
+       flush_dcache_page(pg);
+       kunmap(pg);
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_readpage done\n"));
+       return ret;
+}
+
+static int yaffs_readpage_unlock(struct file *f, struct page *pg)
+{
+       int ret = yaffs_readpage_nolock(f, pg);
+       UnlockPage(pg);
+       return ret;
+}
+
+static int yaffs_readpage(struct file *f, struct page *pg)
+{
+       return yaffs_readpage_unlock(f, pg);
+}
+
+/* writepage inspired by/stolen from smbfs */
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs_writepage(struct page *page, struct writeback_control *wbc)
+#else
+static int yaffs_writepage(struct page *page)
+#endif
+{
+       struct address_space *mapping = page->mapping;
+       loff_t offset = (loff_t) page->index << PAGE_CACHE_SHIFT;
+       struct inode *inode;
+       unsigned long end_index;
+       char *buffer;
+       yaffs_Object *obj;
+       int nWritten = 0;
+       unsigned nBytes;
+
+       if (!mapping)
+               BUG();
+       inode = mapping->host;
+       if (!inode)
+               BUG();
+
+       if (offset > inode->i_size) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG
+                  "yaffs_writepage at %08x, inode size = %08x!!!\n",
+                  (unsigned)(page->index << PAGE_CACHE_SHIFT),
+                  (unsigned)inode->i_size));
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "                -> don't care!!\n"));
+               unlock_page(page);
+               return 0;
+       }
+
+       end_index = inode->i_size >> PAGE_CACHE_SHIFT;
+
+       /* easy case */
+       if (page->index < end_index) {
+               nBytes = PAGE_CACHE_SIZE;
+       } else {
+               nBytes = inode->i_size & (PAGE_CACHE_SIZE - 1);
+       }
+
+       get_page(page);
+
+       buffer = kmap(page);
+
+       obj = yaffs_InodeToObject(inode);
+       yaffs_GrossLock(obj->myDev);
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_writepage at %08x, size %08x\n",
+          (unsigned)(page->index << PAGE_CACHE_SHIFT), nBytes));
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "writepag0: obj = %05x, ino = %05x\n",
+          (int)obj->variant.fileVariant.fileSize, (int)inode->i_size));
+
+       nWritten =
+           yaffs_WriteDataToFile(obj, buffer, page->index << PAGE_CACHE_SHIFT,
+                                 nBytes, 0);
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "writepag1: obj = %05x, ino = %05x\n",
+          (int)obj->variant.fileVariant.fileSize, (int)inode->i_size));
+
+       yaffs_GrossUnlock(obj->myDev);
+
+       kunmap(page);
+       SetPageUptodate(page);
+       UnlockPage(page);
+       put_page(page);
+
+       return (nWritten == nBytes) ? 0 : -ENOSPC;
+}
+
+static int yaffs_prepare_write(struct file *f, struct page *pg,
+                              unsigned offset, unsigned to)
+{
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_prepair_write\n"));
+       if (!Page_Uptodate(pg) && (offset || to < PAGE_CACHE_SIZE))
+               return yaffs_readpage_nolock(f, pg);
+
+       return 0;
+
+}
+
+static int yaffs_commit_write(struct file *f, struct page *pg, unsigned offset,
+                             unsigned to)
+{
+
+       void *addr = page_address(pg) + offset;
+       loff_t pos = (((loff_t) pg->index) << PAGE_CACHE_SHIFT) + offset;
+       int nBytes = to - offset;
+       int nWritten;
+
+       unsigned spos = pos;
+       unsigned saddr = (unsigned)addr;
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_commit_write addr %x pos %x nBytes %d\n", saddr,
+          spos, nBytes));
+
+       nWritten = yaffs_file_write(f, addr, nBytes, &pos);
+
+       if (nWritten != nBytes) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG
+                  "yaffs_commit_write not same size nWritten %d  nBytes %d\n",
+                  nWritten, nBytes));
+               SetPageError(pg);
+               ClearPageUptodate(pg);
+       } else {
+               SetPageUptodate(pg);
+       }
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_commit_write returning %d\n",
+          nWritten == nBytes ? 0 : nWritten));
+
+       return nWritten == nBytes ? 0 : nWritten;
+
+}
+
+static void yaffs_FillInodeFromObject(struct inode *inode, yaffs_Object * obj)
+{
+       if (inode && obj) {
+
+
+               /* Check mode against the variant type and attempt to repair if broken. */
+               __u32 mode = obj->yst_mode;
+               switch( obj->variantType ){
+               case YAFFS_OBJECT_TYPE_FILE :
+                       if( ! S_ISREG(mode) ){
+                               obj->yst_mode &= ~S_IFMT;
+                               obj->yst_mode |= S_IFREG;
+                       }
+ 
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK :
+                       if( ! S_ISLNK(mode) ){
+                               obj->yst_mode &= ~S_IFMT;
+                               obj->yst_mode |= S_IFLNK;
+                       }
+ 
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY :
+                       if( ! S_ISDIR(mode) ){
+                               obj->yst_mode &= ~S_IFMT;
+                               obj->yst_mode |= S_IFDIR;
+                       }
+ 
+                       break;
+               case YAFFS_OBJECT_TYPE_UNKNOWN :
+               case YAFFS_OBJECT_TYPE_HARDLINK :
+               case YAFFS_OBJECT_TYPE_SPECIAL :
+               default:
+                       /* TODO? */
+                       break;
+               }
+
+               inode->i_ino = obj->objectId;
+               inode->i_mode = obj->yst_mode;
+               inode->i_uid = obj->yst_uid;
+               inode->i_gid = obj->yst_gid;
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
+               inode->i_blksize = inode->i_sb->s_blocksize;
+#endif
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+
+               inode->i_rdev = old_decode_dev(obj->yst_rdev);
+               inode->i_atime.tv_sec = (time_t) (obj->yst_atime);
+               inode->i_atime.tv_nsec = 0;
+               inode->i_mtime.tv_sec = (time_t) obj->yst_mtime;
+               inode->i_mtime.tv_nsec = 0;
+               inode->i_ctime.tv_sec = (time_t) obj->yst_ctime;
+               inode->i_ctime.tv_nsec = 0;
+#else
+               inode->i_rdev = obj->yst_rdev;
+               inode->i_atime = obj->yst_atime;
+               inode->i_mtime = obj->yst_mtime;
+               inode->i_ctime = obj->yst_ctime;
+#endif
+               inode->i_size = yaffs_GetObjectFileLength(obj);
+               inode->i_blocks = (inode->i_size + 511) >> 9;
+
+               inode->i_nlink = yaffs_GetObjectLinkCount(obj);
+
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG
+                  "yaffs_FillInode mode %x uid %d gid %d size %d count %d\n",
+                  inode->i_mode, inode->i_uid, inode->i_gid,
+                  (int)inode->i_size, atomic_read(&inode->i_count)));
+
+               switch (obj->yst_mode & S_IFMT) {
+               default:        /* fifo, device or socket */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+                       init_special_inode(inode, obj->yst_mode,
+                                          old_decode_dev(obj->yst_rdev));
+#else
+                       init_special_inode(inode, obj->yst_mode,
+                                          (dev_t) (obj->yst_rdev));
+#endif
+                       break;
+               case S_IFREG:   /* file */
+                       inode->i_op = &yaffs_file_inode_operations;
+                       inode->i_fop = &yaffs_file_operations;
+                       inode->i_mapping->a_ops =
+                           &yaffs_file_address_operations;
+                       break;
+               case S_IFDIR:   /* directory */
+                       inode->i_op = &yaffs_dir_inode_operations;
+                       inode->i_fop = &yaffs_dir_operations;
+                       break;
+               case S_IFLNK:   /* symlink */
+                       inode->i_op = &yaffs_symlink_inode_operations;
+                       break;
+               }
+
+               yaffs_InodeToObjectLV(inode) = obj;
+
+               obj->myInode = inode;
+
+       } else {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_FileInode invalid parameters\n"));
+       }
+
+}
+
+struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,
+                             yaffs_Object * obj)
+{
+       struct inode *inode;
+
+       if (!sb) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_get_inode for NULL super_block!!\n"));
+               return NULL;
+
+       }
+
+       if (!obj) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_get_inode for NULL object!!\n"));
+               return NULL;
+
+       }
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_get_inode for object %d\n", obj->objectId));
+
+       inode = iget(sb, obj->objectId);
+
+       /* NB Side effect: iget calls back to yaffs_read_inode(). */
+       /* iget also increments the inode's i_count */
+       /* NB You can't be holding grossLock or deadlock will happen! */
+
+       return inode;
+}
+
+static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
+                               loff_t * pos)
+{
+       yaffs_Object *obj;
+       int nWritten, ipos;
+       struct inode *inode;
+       yaffs_Device *dev;
+
+       obj = yaffs_DentryToObject(f->f_dentry);
+
+       dev = obj->myDev;
+
+       yaffs_GrossLock(dev);
+
+       inode = f->f_dentry->d_inode;
+
+       if (!S_ISBLK(inode->i_mode) && f->f_flags & O_APPEND) {
+               ipos = inode->i_size;
+       } else {
+               ipos = *pos;
+       }
+
+       if (!obj) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_file_write: hey obj is null!\n"));
+       } else {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG
+                  "yaffs_file_write about to write writing %d bytes"
+                  "to object %d at %d\n",
+                  n, obj->objectId, ipos));
+       }
+
+       nWritten = yaffs_WriteDataToFile(obj, buf, ipos, n, 0);
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_file_write writing %d bytes, %d written at %d\n",
+          n, nWritten, ipos));
+       if (nWritten > 0) {
+               ipos += nWritten;
+               *pos = ipos;
+               if (ipos > inode->i_size) {
+                       inode->i_size = ipos;
+                       inode->i_blocks = (ipos + 511) >> 9;
+
+                       T(YAFFS_TRACE_OS,
+                         (KERN_DEBUG
+                          "yaffs_file_write size updated to %d bytes, "
+                          "%d blocks\n",
+                          ipos, (int)(inode->i_blocks)));
+               }
+
+       }
+       yaffs_GrossUnlock(dev);
+       return nWritten == 0 ? -ENOSPC : nWritten;
+}
+
+static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
+{
+       yaffs_Object *obj;
+       yaffs_Device *dev;
+       struct inode *inode = f->f_dentry->d_inode;
+       unsigned long offset, curoffs;
+       struct list_head *i;
+       yaffs_Object *l;
+
+       char name[YAFFS_MAX_NAME_LENGTH + 1];
+
+       obj = yaffs_DentryToObject(f->f_dentry);
+       dev = obj->myDev;
+
+       yaffs_GrossLock(dev);
+
+       offset = f->f_pos;
+
+       T(YAFFS_TRACE_OS, ("yaffs_readdir: starting at %d\n", (int)offset));
+
+       if (offset == 0) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_readdir: entry . ino %d \n",
+                  (int)inode->i_ino));
+               if (filldir(dirent, ".", 1, offset, inode->i_ino, DT_DIR)
+                   < 0) {
+                       goto out;
+               }
+               offset++;
+               f->f_pos++;
+       }
+       if (offset == 1) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_readdir: entry .. ino %d \n",
+                  (int)f->f_dentry->d_parent->d_inode->i_ino));
+               if (filldir
+                   (dirent, "..", 2, offset,
+                    f->f_dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
+                       goto out;
+               }
+               offset++;
+               f->f_pos++;
+       }
+
+       curoffs = 1;
+
+       /* If the directory has changed since the open or last call to
+          readdir, rewind to after the 2 canned entries. */
+
+       if (f->f_version != inode->i_version) {
+               offset = 2;
+               f->f_pos = offset;
+               f->f_version = inode->i_version;
+       }
+
+       list_for_each(i, &obj->variant.directoryVariant.children) {
+               curoffs++;
+               if (curoffs >= offset) {
+                       l = list_entry(i, yaffs_Object, siblings);
+
+                       yaffs_GetObjectName(l, name,
+                                           YAFFS_MAX_NAME_LENGTH + 1);
+                       T(YAFFS_TRACE_OS,
+                         (KERN_DEBUG "yaffs_readdir: %s inode %d\n", name,
+                          yaffs_GetObjectInode(l)));
+
+                       if (filldir(dirent,
+                                   name,
+                                   strlen(name),
+                                   offset,
+                                   yaffs_GetObjectInode(l),
+                                   yaffs_GetObjectType(l))
+                           < 0) {
+                               goto up_and_out;
+                       }
+
+                       offset++;
+                       f->f_pos++;
+               }
+       }
+
+      up_and_out:
+      out:
+
+       yaffs_GrossUnlock(dev);
+
+       return 0;
+}
+
+/*
+ * File creation. Allocate an inode, and we're done..
+ */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+                      dev_t rdev)
+#else
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+                      int rdev)
+#endif
+{
+       struct inode *inode;
+
+       yaffs_Object *obj = NULL;
+       yaffs_Device *dev;
+
+       yaffs_Object *parent = yaffs_InodeToObject(dir);
+
+       int error = -ENOSPC;
+       uid_t uid = current->fsuid;
+       gid_t gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
+       
+       if((dir->i_mode & S_ISGID) && S_ISDIR(mode))
+               mode |= S_ISGID;
+
+       if (parent) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_mknod: parent object %d type %d\n",
+                  parent->objectId, parent->variantType));
+       } else {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_mknod: could not get parent object\n"));
+               return -EPERM;
+       }
+
+       T(YAFFS_TRACE_OS, ("yaffs_mknod: making oject for %s, "
+                          "mode %x dev %x\n",
+                          dentry->d_name.name, mode, rdev));
+
+       dev = parent->myDev;
+
+       yaffs_GrossLock(dev);
+
+       switch (mode & S_IFMT) {
+       default:
+               /* Special (socket, fifo, device...) */
+               T(YAFFS_TRACE_OS, (KERN_DEBUG
+                                  "yaffs_mknod: making special\n"));
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+               obj =
+                   yaffs_MknodSpecial(parent, dentry->d_name.name, mode, uid,
+                                      gid, old_encode_dev(rdev));
+#else
+               obj =
+                   yaffs_MknodSpecial(parent, dentry->d_name.name, mode, uid,
+                                      gid, rdev);
+#endif
+               break;
+       case S_IFREG:           /* file          */
+               T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_mknod: making file\n"));
+               obj =
+                   yaffs_MknodFile(parent, dentry->d_name.name, mode, uid,
+                                   gid);
+               break;
+       case S_IFDIR:           /* directory */
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_mknod: making directory\n"));
+               obj =
+                   yaffs_MknodDirectory(parent, dentry->d_name.name, mode,
+                                        uid, gid);
+               break;
+       case S_IFLNK:           /* symlink */
+               T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_mknod: making file\n"));
+               obj = NULL;     /* Do we ever get here? */
+               break;
+       }
+       
+       /* Can not call yaffs_get_inode() with gross lock held */
+       yaffs_GrossUnlock(dev);
+
+       if (obj) {
+               inode = yaffs_get_inode(dir->i_sb, mode, rdev, obj);
+               d_instantiate(dentry, inode);
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_mknod created object %d count = %d\n",
+                  obj->objectId, atomic_read(&inode->i_count)));
+               error = 0;
+       } else {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_mknod failed making object\n"));
+               error = -ENOMEM;
+       }
+
+       return error;
+}
+
+static int yaffs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+       int retVal;
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_mkdir\n"));
+       retVal = yaffs_mknod(dir, dentry, mode | S_IFDIR, 0);
+#if 0
+       /* attempt to fix dir bug - didn't work */
+       if (!retVal) {
+               dget(dentry);
+       }
+#endif
+       return retVal;
+}
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode,
+                       struct nameidata *n)
+#else
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode)
+#endif
+{
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_create\n"));
+       return yaffs_mknod(dir, dentry, mode | S_IFREG, 0);
+}
+
+static int yaffs_unlink(struct inode *dir, struct dentry *dentry)
+{
+       int retVal;
+
+       yaffs_Device *dev;
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_unlink %d:%s\n", (int)(dir->i_ino),
+          dentry->d_name.name));
+
+       dev = yaffs_InodeToObject(dir)->myDev;
+
+       yaffs_GrossLock(dev);
+
+       retVal = yaffs_Unlink(yaffs_InodeToObject(dir), dentry->d_name.name);
+
+       if (retVal == YAFFS_OK) {
+               dentry->d_inode->i_nlink--;
+               dir->i_version++;
+               yaffs_GrossUnlock(dev);
+               mark_inode_dirty(dentry->d_inode);
+               return 0;
+       }
+       yaffs_GrossUnlock(dev);
+       return -ENOTEMPTY;
+}
+
+/*
+ * Create a link...
+ */
+static int yaffs_link(struct dentry *old_dentry, struct inode *dir,
+                     struct dentry *dentry)
+{
+       struct inode *inode = old_dentry->d_inode;
+       yaffs_Object *obj = NULL;
+       yaffs_Object *link = NULL;
+       yaffs_Device *dev;
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_link\n"));
+
+       obj = yaffs_InodeToObject(inode);
+       dev = obj->myDev;
+
+       yaffs_GrossLock(dev);
+
+       if (!S_ISDIR(inode->i_mode))    /* Don't link directories */
+       {
+               link =
+                   yaffs_Link(yaffs_InodeToObject(dir), dentry->d_name.name,
+                              obj);
+       }
+
+       if (link) {
+               old_dentry->d_inode->i_nlink = yaffs_GetObjectLinkCount(obj);
+               d_instantiate(dentry, old_dentry->d_inode);
+               atomic_inc(&old_dentry->d_inode->i_count);
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG "yaffs_link link count %d i_count %d\n",
+                  old_dentry->d_inode->i_nlink,
+                  atomic_read(&old_dentry->d_inode->i_count)));
+
+       }
+
+       yaffs_GrossUnlock(dev);
+
+       if (link) {
+
+               return 0;
+       }
+
+       return -EPERM;
+}
+
+static int yaffs_symlink(struct inode *dir, struct dentry *dentry,
+                        const char *symname)
+{
+       yaffs_Object *obj;
+       yaffs_Device *dev;
+       uid_t uid = current->fsuid;
+       gid_t gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_symlink\n"));
+
+       dev = yaffs_InodeToObject(dir)->myDev;
+       yaffs_GrossLock(dev);
+       obj = yaffs_MknodSymLink(yaffs_InodeToObject(dir), dentry->d_name.name,
+                                S_IFLNK | S_IRWXUGO, uid, gid, symname);
+       yaffs_GrossUnlock(dev);
+
+       if (obj) {
+
+               struct inode *inode;
+
+               inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
+               d_instantiate(dentry, inode);
+               T(YAFFS_TRACE_OS, (KERN_DEBUG "symlink created OK\n"));
+               return 0;
+       } else {
+               T(YAFFS_TRACE_OS, (KERN_DEBUG "symlink not created\n"));
+
+       }
+
+       return -ENOMEM;
+}
+
+static int yaffs_sync_object(struct file *file, struct dentry *dentry,
+                            int datasync)
+{
+
+       yaffs_Object *obj;
+       yaffs_Device *dev;
+
+       obj = yaffs_DentryToObject(dentry);
+
+       dev = obj->myDev;
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_sync_object\n"));
+       yaffs_GrossLock(dev);
+       yaffs_FlushFile(obj, 1);
+       yaffs_GrossUnlock(dev);
+       return 0;
+}
+
+/*
+ * The VFS layer already does all the dentry stuff for rename.
+ *
+ * NB: POSIX says you can rename an object over an old object of the same name
+ */
+static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
+                       struct inode *new_dir, struct dentry *new_dentry)
+{
+       yaffs_Device *dev;
+       int retVal = YAFFS_FAIL;
+       yaffs_Object *target;
+
+        T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_rename\n"));
+       dev = yaffs_InodeToObject(old_dir)->myDev;
+
+       yaffs_GrossLock(dev);
+
+       /* Check if the target is an existing directory that is not empty. */
+       target =
+           yaffs_FindObjectByName(yaffs_InodeToObject(new_dir),
+                                  new_dentry->d_name.name);
+       
+       
+
+       if (target &&
+           target->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
+           !list_empty(&target->variant.directoryVariant.children)) {
+           
+               T(YAFFS_TRACE_OS, (KERN_DEBUG "target is non-empty dir\n"));
+
+               retVal = YAFFS_FAIL;
+       } else {
+
+               /* Now does unlinking internally using shadowing mechanism */
+               T(YAFFS_TRACE_OS, (KERN_DEBUG "calling yaffs_RenameObject\n"));
+               
+               retVal =
+                   yaffs_RenameObject(yaffs_InodeToObject(old_dir),
+                                      old_dentry->d_name.name,
+                                      yaffs_InodeToObject(new_dir),
+                                      new_dentry->d_name.name);
+
+       }
+       yaffs_GrossUnlock(dev);
+
+       if (retVal == YAFFS_OK) {
+               if(target) {
+                       new_dentry->d_inode->i_nlink--;
+                       mark_inode_dirty(new_dentry->d_inode);
+               }
+
+               return 0;
+       } else {
+               return -ENOTEMPTY;
+       }
+
+}
+
+static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+       struct inode *inode = dentry->d_inode;
+       int error;
+       yaffs_Device *dev;
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_setattr of object %d\n",
+          yaffs_InodeToObject(inode)->objectId));
+
+       if ((error = inode_change_ok(inode, attr)) == 0) {
+
+               dev = yaffs_InodeToObject(inode)->myDev;
+               yaffs_GrossLock(dev);
+               if (yaffs_SetAttributes(yaffs_InodeToObject(inode), attr) ==
+                   YAFFS_OK) {
+                       error = 0;
+               } else {
+                       error = -EPERM;
+               }
+               yaffs_GrossUnlock(dev);
+               if (!error)
+                       error = inode_setattr(inode, attr);
+       }
+       return error;
+}
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static int yaffs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+       yaffs_Device *dev = yaffs_DentryToObject(dentry)->myDev;
+       struct super_block *sb = dentry->d_sb;
+#elif (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs_statfs(struct super_block *sb, struct kstatfs *buf)
+{
+       yaffs_Device *dev = yaffs_SuperToDevice(sb);
+#else
+static int yaffs_statfs(struct super_block *sb, struct statfs *buf)
+{
+       yaffs_Device *dev = yaffs_SuperToDevice(sb);
+#endif
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_statfs\n"));
+
+       yaffs_GrossLock(dev);
+
+       buf->f_type = YAFFS_MAGIC;
+       buf->f_bsize = sb->s_blocksize;
+       buf->f_namelen = 255;
+       if (sb->s_blocksize > dev->nDataBytesPerChunk) {
+
+               buf->f_blocks =
+                   (dev->endBlock - dev->startBlock +
+                    1) * dev->nChunksPerBlock / (sb->s_blocksize /
+                                                 dev->nDataBytesPerChunk);
+               buf->f_bfree =
+                   yaffs_GetNumberOfFreeChunks(dev) / (sb->s_blocksize /
+                                                       dev->nDataBytesPerChunk);
+       } else {
+
+               buf->f_blocks =
+                   (dev->endBlock - dev->startBlock +
+                    1) * dev->nChunksPerBlock * (dev->nDataBytesPerChunk /
+                                                 sb->s_blocksize);
+               buf->f_bfree =
+                   yaffs_GetNumberOfFreeChunks(dev) * (dev->nDataBytesPerChunk /
+                                                       sb->s_blocksize);
+       }
+       buf->f_files = 0;
+       buf->f_ffree = 0;
+       buf->f_bavail = buf->f_bfree;
+
+       yaffs_GrossUnlock(dev);
+       return 0;
+}
+
+
+/**
+static int yaffs_do_sync_fs(struct super_block *sb)
+{
+
+       yaffs_Device *dev = yaffs_SuperToDevice(sb);
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_do_sync_fs\n"));
+
+       if(sb->s_dirt) {
+               yaffs_GrossLock(dev);
+
+               if(dev)
+                       yaffs_CheckpointSave(dev);
+               
+               yaffs_GrossUnlock(dev);
+
+               sb->s_dirt = 0;
+       }
+       return 0;
+}
+**/
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static void yaffs_write_super(struct super_block *sb)
+#else
+static int yaffs_write_super(struct super_block *sb)
+#endif
+{
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_write_super\n"));
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18))
+       return 0; /* yaffs_do_sync_fs(sb);*/
+#endif
+}
+
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static int yaffs_sync_fs(struct super_block *sb, int wait)
+#else
+static int yaffs_sync_fs(struct super_block *sb)
+#endif
+{
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_sync_fs\n"));
+       
+       return 0; /* yaffs_do_sync_fs(sb);*/
+       
+}
+
+
+static void yaffs_read_inode(struct inode *inode)
+{
+       /* NB This is called as a side effect of other functions, but
+        * we had to release the lock to prevent deadlocks, so 
+        * need to lock again.
+        */
+
+       yaffs_Object *obj;
+       yaffs_Device *dev = yaffs_SuperToDevice(inode->i_sb);
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_read_inode for %d\n", (int)inode->i_ino));
+
+       yaffs_GrossLock(dev);
+       
+       obj = yaffs_FindObjectByNumber(dev, inode->i_ino);
+
+       yaffs_FillInodeFromObject(inode, obj);
+
+       yaffs_GrossUnlock(dev);
+}
+
+static LIST_HEAD(yaffs_dev_list);
+
+static int yaffs_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+       yaffs_Device    *dev = yaffs_SuperToDevice(sb);
+
+       if( *flags & MS_RDONLY ) {
+               struct mtd_info *mtd = yaffs_SuperToDevice(sb)->genericDevice;
+           
+               T(YAFFS_TRACE_OS,
+                       (KERN_DEBUG "yaffs_remount_fs: %s: RO\n", dev->name ));
+
+               yaffs_GrossLock(dev);
+        
+               yaffs_FlushEntireDeviceCache(dev);
+       
+               yaffs_CheckpointSave(dev);
+ 
+               if (mtd->sync)
+                       mtd->sync(mtd);
+
+               yaffs_GrossUnlock(dev);
+       }
+       else {
+               T(YAFFS_TRACE_OS, 
+                       (KERN_DEBUG "yaffs_remount_fs: %s: RW\n", dev->name ));
+       }
+ 
+       return 0;
+}
+
+static void yaffs_put_super(struct super_block *sb)
+{
+       yaffs_Device *dev = yaffs_SuperToDevice(sb);
+
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_put_super\n"));
+
+       yaffs_GrossLock(dev);
+       
+       yaffs_FlushEntireDeviceCache(dev);
+
+       yaffs_CheckpointSave(dev);
+
+       if (dev->putSuperFunc) {
+               dev->putSuperFunc(sb);
+       }
+
+       yaffs_Deinitialise(dev);
+       
+       yaffs_GrossUnlock(dev);
+
+       /* we assume this is protected by lock_kernel() in mount/umount */
+       list_del(&dev->devList);
+       
+       if(dev->spareBuffer){
+               YFREE(dev->spareBuffer);
+               dev->spareBuffer = NULL;
+       }
+
+       kfree(dev);
+}
+
+
+static void yaffs_MTDPutSuper(struct super_block *sb)
+{
+
+       struct mtd_info *mtd = yaffs_SuperToDevice(sb)->genericDevice;
+
+       if (mtd->sync) {
+               mtd->sync(mtd);
+       }
+
+       put_mtd_device(mtd);
+}
+
+
+static void yaffs_MarkSuperBlockDirty(void *vsb)
+{
+       struct super_block *sb = (struct super_block *)vsb;
+       
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_MarkSuperBlockDirty() sb = %p\n",sb));
+//     if(sb)
+//             sb->s_dirt = 1;
+}
+
+typedef struct {
+       int inband_tags;
+       int skip_checkpoint_read;
+       int skip_checkpoint_write;
+       int no_cache;
+} yaffs_options;
+
+#define MAX_OPT_LEN 20
+static int yaffs_parse_options(yaffs_options *options, const char *options_str)
+{
+       char cur_opt[MAX_OPT_LEN+1];
+       int p;
+       int error = 0;
+       
+       /* Parse through the options which is a comma seperated list */
+       
+       while(options_str && *options_str && !error){
+               memset(cur_opt,0,MAX_OPT_LEN+1);
+               p = 0;
+               
+               while(*options_str && *options_str != ','){
+                       if(p < MAX_OPT_LEN){
+                               cur_opt[p] = *options_str;
+                               p++;
+                       }
+                       options_str++;
+               }
+               
+               if(!strcmp(cur_opt,"inband-tags"))
+                       options->inband_tags = 1;
+               else if(!strcmp(cur_opt,"no-cache"))
+                       options->no_cache = 1;
+               else if(!strcmp(cur_opt,"no-checkpoint-read"))
+                       options->skip_checkpoint_read = 1;
+               else if(!strcmp(cur_opt,"no-checkpoint-write"))
+                       options->skip_checkpoint_write = 1;
+               else if(!strcmp(cur_opt,"no-checkpoint")){
+                       options->skip_checkpoint_read = 1;
+                       options->skip_checkpoint_write = 1;
+               } else {
+                       printk(KERN_INFO "yaffs: Bad mount option \"%s\"\n",cur_opt);
+                       error = 1;
+               }
+               
+       }
+
+       return error;
+}
+
+static struct super_block *yaffs_internal_read_super(int yaffsVersion,
+                                                    struct super_block *sb,
+                                                    void *data, int silent)
+{
+       int nBlocks;
+       struct inode *inode = NULL;
+       struct dentry *root;
+       yaffs_Device *dev = 0;
+       char devname_buf[BDEVNAME_SIZE + 1];
+       struct mtd_info *mtd;
+       int err;
+       char *data_str = (char *)data;
+       
+       yaffs_options options;
+
+       sb->s_magic = YAFFS_MAGIC;
+       sb->s_op = &yaffs_super_ops;
+
+       if (!sb)
+               printk(KERN_INFO "yaffs: sb is NULL\n");
+       else if (!sb->s_dev)
+               printk(KERN_INFO "yaffs: sb->s_dev is NULL\n");
+       else if (!yaffs_devname(sb, devname_buf))
+               printk(KERN_INFO "yaffs: devname is NULL\n");
+       else
+               printk(KERN_INFO "yaffs: dev is %d name is \"%s\"\n",
+                      sb->s_dev,
+                      yaffs_devname(sb, devname_buf));
+                   
+       if(!data_str)
+               data_str = "";
+   
+       printk(KERN_INFO "yaffs: passed flags \"%s\"\n",data_str);
+       
+       memset(&options,0,sizeof(options));
+       
+       if(yaffs_parse_options(&options,data_str)){
+               /* Option parsing failed */
+               return NULL;
+       }
+
+
+       sb->s_blocksize = PAGE_CACHE_SIZE;
+       sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+       T(YAFFS_TRACE_OS, ("yaffs_read_super: Using yaffs%d\n", yaffsVersion));
+       T(YAFFS_TRACE_OS,
+         ("yaffs_read_super: block size %d\n", (int)(sb->s_blocksize)));
+
+#ifdef CONFIG_YAFFS_DISABLE_WRITE_VERIFY
+       T(YAFFS_TRACE_OS,
+         ("yaffs: Write verification disabled. All guarantees "
+          "null and void\n"));
+#endif
+
+       T(YAFFS_TRACE_ALWAYS, ("yaffs: Attempting MTD mount on %u.%u, "
+                              "\"%s\"\n",
+                              MAJOR(sb->s_dev), MINOR(sb->s_dev),
+                              yaffs_devname(sb, devname_buf)));
+
+       /* Check it's an mtd device..... */
+       if (MAJOR(sb->s_dev) != MTD_BLOCK_MAJOR) {
+               return NULL;    /* This isn't an mtd device */
+       }
+       /* Get the device */
+       mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
+       if (!mtd) {
+               T(YAFFS_TRACE_ALWAYS,
+                 ("yaffs: MTD device #%u doesn't appear to exist\n",
+                  MINOR(sb->s_dev)));
+               return NULL;
+       }
+       /* Check it's NAND */
+       if (mtd->type != MTD_NANDFLASH) {
+               T(YAFFS_TRACE_ALWAYS,
+                 ("yaffs: MTD device is not NAND it's type %d\n", mtd->type));
+               return NULL;
+       }
+
+       T(YAFFS_TRACE_OS, (" erase %p\n", mtd->erase));
+       T(YAFFS_TRACE_OS, (" read %p\n", mtd->read));
+       T(YAFFS_TRACE_OS, (" write %p\n", mtd->write));
+       T(YAFFS_TRACE_OS, (" readoob %p\n", mtd->read_oob));
+       T(YAFFS_TRACE_OS, (" writeoob %p\n", mtd->write_oob));
+       T(YAFFS_TRACE_OS, (" block_isbad %p\n", mtd->block_isbad));
+       T(YAFFS_TRACE_OS, (" block_markbad %p\n", mtd->block_markbad));
+       T(YAFFS_TRACE_OS, (" %s %d\n", WRITE_SIZE_STR, WRITE_SIZE(mtd)));
+       T(YAFFS_TRACE_OS, (" oobsize %d\n", mtd->oobsize));
+       T(YAFFS_TRACE_OS, (" erasesize %d\n", mtd->erasesize));
+       T(YAFFS_TRACE_OS, (" size %d\n", mtd->size));
+       
+#ifdef CONFIG_YAFFS_AUTO_YAFFS2
+
+       if (yaffsVersion == 1 && 
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+           mtd->writesize >= 2048) {
+#else
+           mtd->oobblock >= 2048) {
+#endif
+           T(YAFFS_TRACE_ALWAYS,("yaffs: auto selecting yaffs2\n"));
+           yaffsVersion = 2;
+       }       
+       
+       /* Added NCB 26/5/2006 for completeness */
+       if (yaffsVersion == 2 && 
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+           mtd->writesize == 512) {
+#else
+           mtd->oobblock == 512) {
+#endif
+           T(YAFFS_TRACE_ALWAYS,("yaffs: auto selecting yaffs1\n"));
+           yaffsVersion = 1;
+       }       
+
+#endif
+
+       if (yaffsVersion == 2) {
+               /* Check for version 2 style functions */
+               if (!mtd->erase ||
+                   !mtd->block_isbad ||
+                   !mtd->block_markbad ||
+                   !mtd->read ||
+                   !mtd->write ||
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+                   !mtd->read_oob || !mtd->write_oob) {
+#else
+                   !mtd->write_ecc ||
+                   !mtd->read_ecc || !mtd->read_oob || !mtd->write_oob) {
+#endif
+                       T(YAFFS_TRACE_ALWAYS,
+                         ("yaffs: MTD device does not support required "
+                          "functions\n"));;
+                       return NULL;
+               }
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+               if (mtd->writesize < YAFFS_MIN_YAFFS2_CHUNK_SIZE ||
+#else
+               if (mtd->oobblock < YAFFS_MIN_YAFFS2_CHUNK_SIZE ||
+#endif
+                   mtd->oobsize < YAFFS_MIN_YAFFS2_SPARE_SIZE) {
+                       T(YAFFS_TRACE_ALWAYS,
+                         ("yaffs: MTD device does not have the "
+                          "right page sizes\n"));
+                       return NULL;
+               }
+       } else {
+               /* Check for V1 style functions */
+               if (!mtd->erase ||
+                   !mtd->read ||
+                   !mtd->write ||
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+                   !mtd->read_oob || !mtd->write_oob) {
+#else
+                   !mtd->write_ecc ||
+                   !mtd->read_ecc || !mtd->read_oob || !mtd->write_oob) {
+#endif
+                       T(YAFFS_TRACE_ALWAYS,
+                         ("yaffs: MTD device does not support required "
+                          "functions\n"));;
+                       return NULL;
+               }
+
+               if (WRITE_SIZE(mtd) < YAFFS_BYTES_PER_CHUNK ||
+                   mtd->oobsize != YAFFS_BYTES_PER_SPARE) {
+                       T(YAFFS_TRACE_ALWAYS,
+                         ("yaffs: MTD device does not support have the "
+                          "right page sizes\n"));
+                       return NULL;
+               }
+       }
+
+       /* OK, so if we got here, we have an MTD that's NAND and looks
+        * like it has the right capabilities
+        * Set the yaffs_Device up for mtd
+        */
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+       sb->s_fs_info = dev = kmalloc(sizeof(yaffs_Device), GFP_KERNEL);
+#else
+       sb->u.generic_sbp = dev = kmalloc(sizeof(yaffs_Device), GFP_KERNEL);
+#endif
+       if (!dev) {
+               /* Deep shit could not allocate device structure */
+               T(YAFFS_TRACE_ALWAYS,
+                 ("yaffs_read_super: Failed trying to allocate "
+                  "yaffs_Device. \n"));
+               return NULL;
+       }
+
+       memset(dev, 0, sizeof(yaffs_Device));
+       dev->genericDevice = mtd;
+       dev->name = mtd->name;
+
+       /* Set up the memory size parameters.... */
+
+       nBlocks = mtd->size / (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK);
+       dev->startBlock = 0;
+       dev->endBlock = nBlocks - 1;
+       dev->nChunksPerBlock = YAFFS_CHUNKS_PER_BLOCK;
+       dev->nDataBytesPerChunk = YAFFS_BYTES_PER_CHUNK;
+       dev->nReservedBlocks = 5;
+       dev->nShortOpCaches = (options.no_cache) ? 0 : 10;
+
+       /* ... and the functions. */
+       if (yaffsVersion == 2) {
+               dev->writeChunkWithTagsToNAND =
+                   nandmtd2_WriteChunkWithTagsToNAND;
+               dev->readChunkWithTagsFromNAND =
+                   nandmtd2_ReadChunkWithTagsFromNAND;
+               dev->markNANDBlockBad = nandmtd2_MarkNANDBlockBad;
+               dev->queryNANDBlock = nandmtd2_QueryNANDBlock;
+               dev->spareBuffer = YMALLOC(mtd->oobsize);
+               dev->isYaffs2 = 1;
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+               dev->nDataBytesPerChunk = mtd->writesize;
+               dev->nChunksPerBlock = mtd->erasesize / mtd->writesize;
+#else
+               dev->nDataBytesPerChunk = mtd->oobblock;
+               dev->nChunksPerBlock = mtd->erasesize / mtd->oobblock;
+#endif
+               nBlocks = mtd->size / mtd->erasesize;
+
+               dev->nCheckpointReservedBlocks = CONFIG_YAFFS_CHECKPOINT_RESERVED_BLOCKS;
+               dev->startBlock = 0;
+               dev->endBlock = nBlocks - 1;
+       } else {
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+               /* use the MTD interface in yaffs_mtdif1.c */
+               dev->writeChunkWithTagsToNAND =
+                       nandmtd1_WriteChunkWithTagsToNAND;
+               dev->readChunkWithTagsFromNAND =
+                       nandmtd1_ReadChunkWithTagsFromNAND;
+               dev->markNANDBlockBad = nandmtd1_MarkNANDBlockBad;
+               dev->queryNANDBlock = nandmtd1_QueryNANDBlock;
+#else
+               dev->writeChunkToNAND = nandmtd_WriteChunkToNAND;
+               dev->readChunkFromNAND = nandmtd_ReadChunkFromNAND;
+#endif
+               dev->isYaffs2 = 0;
+       }
+       /* ... and common functions */
+       dev->eraseBlockInNAND = nandmtd_EraseBlockInNAND;
+       dev->initialiseNAND = nandmtd_InitialiseNAND;
+
+       dev->putSuperFunc = yaffs_MTDPutSuper;
+       
+       dev->superBlock = (void *)sb;
+       dev->markSuperBlockDirty = yaffs_MarkSuperBlockDirty;
+       
+
+#ifndef CONFIG_YAFFS_DOES_ECC
+       dev->useNANDECC = 1;
+#endif
+
+#ifdef CONFIG_YAFFS_DISABLE_WIDE_TNODES
+       dev->wideTnodesDisabled = 1;
+#endif
+
+       dev->skipCheckpointRead = options.skip_checkpoint_read;
+       dev->skipCheckpointWrite = options.skip_checkpoint_write;
+       
+       /* we assume this is protected by lock_kernel() in mount/umount */
+       list_add_tail(&dev->devList, &yaffs_dev_list);
+
+       init_MUTEX(&dev->grossLock);
+
+       yaffs_GrossLock(dev);
+
+       err = yaffs_GutsInitialise(dev);
+
+       T(YAFFS_TRACE_OS,
+         ("yaffs_read_super: guts initialised %s\n",
+          (err == YAFFS_OK) ? "OK" : "FAILED"));
+       
+       /* Release lock before yaffs_get_inode() */
+       yaffs_GrossUnlock(dev);
+
+       /* Create root inode */
+       if (err == YAFFS_OK)
+               inode = yaffs_get_inode(sb, S_IFDIR | 0755, 0,
+                                       yaffs_Root(dev));
+
+       if (!inode)
+               return NULL;
+
+       inode->i_op = &yaffs_dir_inode_operations;
+       inode->i_fop = &yaffs_dir_operations;
+
+       T(YAFFS_TRACE_OS, ("yaffs_read_super: got root inode\n"));
+
+       root = d_alloc_root(inode);
+
+       T(YAFFS_TRACE_OS, ("yaffs_read_super: d_alloc_root done\n"));
+
+       if (!root) {
+               iput(inode);
+               return NULL;
+       }
+       sb->s_root = root;
+
+       T(YAFFS_TRACE_OS, ("yaffs_read_super: done\n"));
+       return sb;
+}
+
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs_internal_read_super_mtd(struct super_block *sb, void *data,
+                                        int silent)
+{
+       return yaffs_internal_read_super(1, sb, data, silent) ? 0 : -EINVAL;
+}
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static int yaffs_read_super(struct file_system_type *fs,
+                           int flags, const char *dev_name,
+                           void *data, struct vfsmount *mnt)
+{
+
+       return get_sb_bdev(fs, flags, dev_name, data,
+                          yaffs_internal_read_super_mtd, mnt);
+}
+#else
+static struct super_block *yaffs_read_super(struct file_system_type *fs,
+                                           int flags, const char *dev_name,
+                                           void *data)
+{
+
+       return get_sb_bdev(fs, flags, dev_name, data,
+                          yaffs_internal_read_super_mtd);
+}
+#endif
+
+static struct file_system_type yaffs_fs_type = {
+       .owner = THIS_MODULE,
+       .name = "yaffs",
+       .get_sb = yaffs_read_super,
+       .kill_sb = kill_block_super,
+       .fs_flags = FS_REQUIRES_DEV,
+};
+#else
+static struct super_block *yaffs_read_super(struct super_block *sb, void *data,
+                                           int silent)
+{
+       return yaffs_internal_read_super(1, sb, data, silent);
+}
+
+static DECLARE_FSTYPE(yaffs_fs_type, "yaffs", yaffs_read_super,
+                     FS_REQUIRES_DEV);
+#endif
+
+
+#ifdef CONFIG_YAFFS_YAFFS2
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+static int yaffs2_internal_read_super_mtd(struct super_block *sb, void *data,
+                                         int silent)
+{
+       return yaffs_internal_read_super(2, sb, data, silent) ? 0 : -EINVAL;
+}
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static int yaffs2_read_super(struct file_system_type *fs,
+                       int flags, const char *dev_name, void *data,
+                       struct vfsmount *mnt)
+{
+       return get_sb_bdev(fs, flags, dev_name, data,
+                       yaffs2_internal_read_super_mtd, mnt);
+}
+#else
+static struct super_block *yaffs2_read_super(struct file_system_type *fs,
+                                            int flags, const char *dev_name,
+                                            void *data)
+{
+
+       return get_sb_bdev(fs, flags, dev_name, data,
+                          yaffs2_internal_read_super_mtd);
+}
+#endif
+
+static struct file_system_type yaffs2_fs_type = {
+       .owner = THIS_MODULE,
+       .name = "yaffs2",
+       .get_sb = yaffs2_read_super,
+       .kill_sb = kill_block_super,
+       .fs_flags = FS_REQUIRES_DEV,
+};
+#else
+static struct super_block *yaffs2_read_super(struct super_block *sb,
+                                            void *data, int silent)
+{
+       return yaffs_internal_read_super(2, sb, data, silent);
+}
+
+static DECLARE_FSTYPE(yaffs2_fs_type, "yaffs2", yaffs2_read_super,
+                     FS_REQUIRES_DEV);
+#endif
+
+#endif                         /* CONFIG_YAFFS_YAFFS2 */
+
+static struct proc_dir_entry *my_proc_entry;
+
+static char *yaffs_dump_dev(char *buf, yaffs_Device * dev)
+{
+       buf += sprintf(buf, "startBlock......... %d\n", dev->startBlock);
+       buf += sprintf(buf, "endBlock........... %d\n", dev->endBlock);
+       buf += sprintf(buf, "nDataBytesPerChunk. %d\n", dev->nDataBytesPerChunk);
+       buf += sprintf(buf, "chunkGroupBits..... %d\n", dev->chunkGroupBits);
+       buf += sprintf(buf, "chunkGroupSize..... %d\n", dev->chunkGroupSize);
+       buf += sprintf(buf, "nErasedBlocks...... %d\n", dev->nErasedBlocks);
+       buf += sprintf(buf, "nReservedBlocks.... %d\n", dev->nReservedBlocks);
+       buf += sprintf(buf, "nCheckptResBlocks.. %d\n", dev->nCheckpointReservedBlocks);
+       buf += sprintf(buf, "blocksInCheckpoint. %d\n", dev->blocksInCheckpoint);
+       buf += sprintf(buf, "nTnodesCreated..... %d\n", dev->nTnodesCreated);
+       buf += sprintf(buf, "nFreeTnodes........ %d\n", dev->nFreeTnodes);
+       buf += sprintf(buf, "nObjectsCreated.... %d\n", dev->nObjectsCreated);
+       buf += sprintf(buf, "nFreeObjects....... %d\n", dev->nFreeObjects);
+       buf += sprintf(buf, "nFreeChunks........ %d\n", dev->nFreeChunks);
+       buf += sprintf(buf, "nPageWrites........ %d\n", dev->nPageWrites);
+       buf += sprintf(buf, "nPageReads......... %d\n", dev->nPageReads);
+       buf += sprintf(buf, "nBlockErasures..... %d\n", dev->nBlockErasures);
+       buf += sprintf(buf, "nGCCopies.......... %d\n", dev->nGCCopies);
+       buf +=
+           sprintf(buf, "garbageCollections. %d\n", dev->garbageCollections);
+       buf +=
+           sprintf(buf, "passiveGCs......... %d\n",
+                   dev->passiveGarbageCollections);
+       buf += sprintf(buf, "nRetriedWrites..... %d\n", dev->nRetriedWrites);
+       buf += sprintf(buf, "nShortOpCaches..... %d\n", dev->nShortOpCaches);
+       buf += sprintf(buf, "nRetireBlocks...... %d\n", dev->nRetiredBlocks);
+       buf += sprintf(buf, "eccFixed........... %d\n", dev->eccFixed);
+       buf += sprintf(buf, "eccUnfixed......... %d\n", dev->eccUnfixed);
+       buf += sprintf(buf, "tagsEccFixed....... %d\n", dev->tagsEccFixed);
+       buf += sprintf(buf, "tagsEccUnfixed..... %d\n", dev->tagsEccUnfixed);
+       buf += sprintf(buf, "cacheHits.......... %d\n", dev->cacheHits);
+       buf += sprintf(buf, "nDeletedFiles...... %d\n", dev->nDeletedFiles);
+       buf += sprintf(buf, "nUnlinkedFiles..... %d\n", dev->nUnlinkedFiles);
+       buf +=
+           sprintf(buf, "nBackgroudDeletions %d\n", dev->nBackgroundDeletions);
+       buf += sprintf(buf, "useNANDECC......... %d\n", dev->useNANDECC);
+       buf += sprintf(buf, "isYaffs2........... %d\n", dev->isYaffs2);
+
+       return buf;
+}
+
+static int yaffs_proc_read(char *page,
+                          char **start,
+                          off_t offset, int count, int *eof, void *data)
+{
+       struct list_head *item;
+       char *buf = page;
+       int step = offset;
+       int n = 0;
+
+       /* Get proc_file_read() to step 'offset' by one on each sucessive call.
+        * We use 'offset' (*ppos) to indicate where we are in devList.
+        * This also assumes the user has posted a read buffer large
+        * enough to hold the complete output; but that's life in /proc.
+        */
+
+       *(int *)start = 1;
+
+       /* Print header first */
+       if (step == 0) {
+               buf += sprintf(buf, "YAFFS built:" __DATE__ " " __TIME__
+                              "\n%s\n%s\n", yaffs_fs_c_version,
+                              yaffs_guts_c_version);
+       }
+
+       /* hold lock_kernel while traversing yaffs_dev_list */
+       lock_kernel();
+
+       /* Locate and print the Nth entry.  Order N-squared but N is small. */
+       list_for_each(item, &yaffs_dev_list) {
+               yaffs_Device *dev = list_entry(item, yaffs_Device, devList);
+               if (n < step) {
+                       n++;
+                       continue;
+               }
+               buf += sprintf(buf, "\nDevice %d \"%s\"\n", n, dev->name);
+               buf = yaffs_dump_dev(buf, dev);
+               break;
+       }
+       unlock_kernel();
+
+       return buf - page < count ? buf - page : count;
+}
+
+/**
+ * Set the verbosity of the warnings and error messages.
+ *
+ * Note that the names can only be a..z or _ with the current code.
+ */
+
+static struct {
+       char *mask_name;
+       unsigned mask_bitfield;
+} mask_flags[] = {
+       {"allocate", YAFFS_TRACE_ALLOCATE},
+       {"always", YAFFS_TRACE_ALWAYS},
+       {"bad_blocks", YAFFS_TRACE_BAD_BLOCKS},
+       {"buffers", YAFFS_TRACE_BUFFERS},
+       {"bug", YAFFS_TRACE_BUG},
+       {"checkpt", YAFFS_TRACE_CHECKPOINT},
+       {"deletion", YAFFS_TRACE_DELETION},
+       {"erase", YAFFS_TRACE_ERASE},
+       {"error", YAFFS_TRACE_ERROR},
+       {"gc_detail", YAFFS_TRACE_GC_DETAIL},
+       {"gc", YAFFS_TRACE_GC},
+       {"mtd", YAFFS_TRACE_MTD},
+       {"nandaccess", YAFFS_TRACE_NANDACCESS},
+       {"os", YAFFS_TRACE_OS},
+       {"scan_debug", YAFFS_TRACE_SCAN_DEBUG},
+       {"scan", YAFFS_TRACE_SCAN},
+       {"tracing", YAFFS_TRACE_TRACING},
+
+       {"verify", YAFFS_TRACE_VERIFY},
+       {"verify_nand", YAFFS_TRACE_VERIFY_NAND},
+       {"verify_full", YAFFS_TRACE_VERIFY_FULL},
+       {"verify_all", YAFFS_TRACE_VERIFY_ALL},
+
+       {"write", YAFFS_TRACE_WRITE},
+       {"all", 0xffffffff},
+       {"none", 0},
+       {NULL, 0},
+};
+
+#define MAX_MASK_NAME_LENGTH 40
+static int yaffs_proc_write(struct file *file, const char *buf,
+                                        unsigned long count, void *data)
+{
+       unsigned rg = 0, mask_bitfield;
+       char *end;
+       char *mask_name;
+       char *x; 
+       char substring[MAX_MASK_NAME_LENGTH+1];
+       int i;
+       int done = 0;
+       int add, len = 0;
+       int pos = 0;
+
+       rg = yaffs_traceMask;
+
+       while (!done && (pos < count)) {
+               done = 1;
+               while ((pos < count) && isspace(buf[pos])) {
+                       pos++;
+               }
+
+               switch (buf[pos]) {
+               case '+':
+               case '-':
+               case '=':
+                       add = buf[pos];
+                       pos++;
+                       break;
+
+               default:
+                       add = ' ';
+                       break;
+               }
+               mask_name = NULL;
+               
+               mask_bitfield = simple_strtoul(buf + pos, &end, 0);
+               if (end > buf + pos) {
+                       mask_name = "numeral";
+                       len = end - (buf + pos);
+                       done = 0;
+               } else {
+                       for(x = buf + pos, i = 0; 
+                           (*x == '_' || (*x >='a' && *x <= 'z')) &&
+                           i <MAX_MASK_NAME_LENGTH; x++, i++, pos++)
+                           substring[i] = *x;
+                       substring[i] = '\0';
+                       
+                       for (i = 0; mask_flags[i].mask_name != NULL; i++) {
+                               //len = strlen(mask_flags[i].mask_name);
+                               //if (strncmp(buf + pos, mask_flags[i].mask_name, len) == 0) {
+                               if(strcmp(substring,mask_flags[i].mask_name) == 0){
+                                       mask_name = mask_flags[i].mask_name;
+                                       mask_bitfield = mask_flags[i].mask_bitfield;
+                                       done = 0;
+                                       break;
+                               }
+                       }
+               }
+
+               if (mask_name != NULL) {
+                       // pos += len;
+                       done = 0;
+                       switch(add) {
+                       case '-':
+                               rg &= ~mask_bitfield;
+                               break;
+                       case '+':
+                               rg |= mask_bitfield;
+                               break;
+                       case '=':
+                               rg = mask_bitfield;
+                               break;
+                       default:
+                               rg |= mask_bitfield;
+                               break;
+                       }
+               }
+       }
+
+       yaffs_traceMask = rg | YAFFS_TRACE_ALWAYS;
+       
+       printk("new trace = 0x%08X\n",yaffs_traceMask);
+       
+       if (rg & YAFFS_TRACE_ALWAYS) {
+               for (i = 0; mask_flags[i].mask_name != NULL; i++) {
+                       char flag;
+                       flag = ((rg & mask_flags[i].mask_bitfield) == mask_flags[i].mask_bitfield) ? '+' : '-';
+                       printk("%c%s\n", flag, mask_flags[i].mask_name);
+               }
+       }
+
+       return count;
+}
+
+/* Stuff to handle installation of file systems */
+struct file_system_to_install {
+       struct file_system_type *fst;
+       int installed;
+};
+
+static struct file_system_to_install fs_to_install[] = {
+//#ifdef CONFIG_YAFFS_YAFFS1
+       {&yaffs_fs_type, 0},
+//#endif
+//#ifdef CONFIG_YAFFS_YAFFS2
+       {&yaffs2_fs_type, 0},
+//#endif
+       {NULL, 0}
+};
+
+static int __init init_yaffs_fs(void)
+{
+       int error = 0;
+       struct file_system_to_install *fsinst;
+
+       T(YAFFS_TRACE_ALWAYS,
+         ("yaffs " __DATE__ " " __TIME__ " Installing. \n"));
+
+       /* Install the proc_fs entry */
+       my_proc_entry = create_proc_entry("yaffs",
+                                              S_IRUGO | S_IFREG,
+                                              &proc_root);
+
+       if (my_proc_entry) {
+               my_proc_entry->write_proc = yaffs_proc_write;
+               my_proc_entry->read_proc = yaffs_proc_read;
+               my_proc_entry->data = NULL;
+       } else {
+               return -ENOMEM;
+       }
+
+       /* Now add the file system entries */
+
+       fsinst = fs_to_install;
+
+       while (fsinst->fst && !error) {
+               error = register_filesystem(fsinst->fst);
+               if (!error) {
+                       fsinst->installed = 1;
+               }
+               fsinst++;
+       }
+
+       /* Any errors? uninstall  */
+       if (error) {
+               fsinst = fs_to_install;
+
+               while (fsinst->fst) {
+                       if (fsinst->installed) {
+                               unregister_filesystem(fsinst->fst);
+                               fsinst->installed = 0;
+                       }
+                       fsinst++;
+               }
+       }
+
+       return error;
+}
+
+static void __exit exit_yaffs_fs(void)
+{
+
+       struct file_system_to_install *fsinst;
+
+       T(YAFFS_TRACE_ALWAYS, ("yaffs " __DATE__ " " __TIME__
+                              " removing. \n"));
+
+       remove_proc_entry("yaffs", &proc_root);
+
+       fsinst = fs_to_install;
+
+       while (fsinst->fst) {
+               if (fsinst->installed) {
+                       unregister_filesystem(fsinst->fst);
+                       fsinst->installed = 0;
+               }
+               fsinst++;
+       }
+
+}
+
+module_init(init_yaffs_fs)
+module_exit(exit_yaffs_fs)
+
+MODULE_DESCRIPTION("YAFFS2 - a NAND specific flash file system");
+MODULE_AUTHOR("Charles Manning, Aleph One Ltd., 2002-2006");
+MODULE_LICENSE("GPL");
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_guts.c linux-2.6.21.1.new/fs/yaffs2/yaffs_guts.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_guts.c       1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_guts.c   2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,7469 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+const char *yaffs_guts_c_version =
+    "$Id: yaffs_guts.c,v 1.49 2007-05-15 20:07:40 charles Exp $";
+
+#include "yportenv.h"
+
+#include "yaffsinterface.h"
+#include "yaffs_guts.h"
+#include "yaffs_tagsvalidity.h"
+
+#include "yaffs_tagscompat.h"
+#ifndef  CONFIG_YAFFS_USE_OWN_SORT
+#include "yaffs_qsort.h"
+#endif
+#include "yaffs_nand.h"
+
+#include "yaffs_checkptrw.h"
+
+#include "yaffs_nand.h"
+#include "yaffs_packedtags2.h"
+
+
+#ifdef CONFIG_YAFFS_WINCE
+void yfsd_LockYAFFS(BOOL fsLockOnly);
+void yfsd_UnlockYAFFS(BOOL fsLockOnly);
+#endif
+
+#define YAFFS_PASSIVE_GC_CHUNKS 2
+
+#include "yaffs_ecc.h"
+
+
+/* Robustification (if it ever comes about...) */
+static void yaffs_RetireBlock(yaffs_Device * dev, int blockInNAND);
+static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND, int erasedOk);
+static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
+                                    const __u8 * data,
+                                    const yaffs_ExtendedTags * tags);
+static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
+                                   const yaffs_ExtendedTags * tags);
+
+/* Other local prototypes */
+static int yaffs_UnlinkObject( yaffs_Object *obj);
+static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj);
+
+static void yaffs_HardlinkFixup(yaffs_Device *dev, yaffs_Object *hardList);
+
+static int yaffs_WriteNewChunkWithTagsToNAND(yaffs_Device * dev,
+                                            const __u8 * buffer,
+                                            yaffs_ExtendedTags * tags,
+                                            int useReserve);
+static int yaffs_PutChunkIntoFile(yaffs_Object * in, int chunkInInode,
+                                 int chunkInNAND, int inScan);
+
+static yaffs_Object *yaffs_CreateNewObject(yaffs_Device * dev, int number,
+                                          yaffs_ObjectType type);
+static void yaffs_AddObjectToDirectory(yaffs_Object * directory,
+                                      yaffs_Object * obj);
+static int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name,
+                                   int force, int isShrink, int shadows);
+static void yaffs_RemoveObjectFromDirectory(yaffs_Object * obj);
+static int yaffs_CheckStructures(void);
+static int yaffs_DeleteWorker(yaffs_Object * in, yaffs_Tnode * tn, __u32 level,
+                             int chunkOffset, int *limit);
+static int yaffs_DoGenericObjectDeletion(yaffs_Object * in);
+
+static yaffs_BlockInfo *yaffs_GetBlockInfo(yaffs_Device * dev, int blockNo);
+
+static __u8 *yaffs_GetTempBuffer(yaffs_Device * dev, int lineNo);
+static void yaffs_ReleaseTempBuffer(yaffs_Device * dev, __u8 * buffer,
+                                   int lineNo);
+
+static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
+                                 int chunkInNAND);
+
+static int yaffs_UnlinkWorker(yaffs_Object * obj);
+static void yaffs_DestroyObject(yaffs_Object * obj);
+
+static int yaffs_TagsMatch(const yaffs_ExtendedTags * tags, int objectId,
+                          int chunkInObject);
+
+loff_t yaffs_GetFileSize(yaffs_Object * obj);
+
+static int yaffs_AllocateChunk(yaffs_Device * dev, int useReserve, yaffs_BlockInfo **blockUsedPtr);
+
+static void yaffs_VerifyFreeChunks(yaffs_Device * dev);
+
+static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in);
+
+#ifdef YAFFS_PARANOID
+static int yaffs_CheckFileSanity(yaffs_Object * in);
+#else
+#define yaffs_CheckFileSanity(in)
+#endif
+
+static void yaffs_InvalidateWholeChunkCache(yaffs_Object * in);
+static void yaffs_InvalidateChunkCache(yaffs_Object * object, int chunkId);
+
+static void yaffs_InvalidateCheckpoint(yaffs_Device *dev);
+
+static int yaffs_FindChunkInFile(yaffs_Object * in, int chunkInInode,
+                                yaffs_ExtendedTags * tags);
+
+static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos);
+static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device * dev,
+                                         yaffs_FileStructure * fStruct,
+                                         __u32 chunkId);
+
+
+/* Function to calculate chunk and offset */
+
+static void yaffs_AddrToChunk(yaffs_Device *dev, loff_t addr, __u32 *chunk, __u32 *offset)
+{
+       if(dev->chunkShift){
+               /* Easy-peasy power of 2 case */
+               *chunk  = (__u32)(addr >> dev->chunkShift);
+               *offset = (__u32)(addr & dev->chunkMask);
+       }
+       else if(dev->crumbsPerChunk)
+       {
+               /* Case where we're using "crumbs" */
+               *offset = (__u32)(addr & dev->crumbMask);
+               addr >>= dev->crumbShift;
+               *chunk = ((__u32)addr)/dev->crumbsPerChunk;
+               *offset += ((addr - (*chunk * dev->crumbsPerChunk)) << dev->crumbShift);
+       }
+       else
+               YBUG();
+}
+
+/* Function to return the number of shifts for a power of 2 greater than or equal 
+ * to the given number
+ * Note we don't try to cater for all possible numbers and this does not have to
+ * be hellishly efficient.
+ */
+ 
+static __u32 ShiftsGE(__u32 x)
+{
+       int extraBits;
+       int nShifts;
+       
+       nShifts = extraBits = 0;
+       
+       while(x>1){
+               if(x & 1) extraBits++;
+               x>>=1;
+               nShifts++;
+       }
+
+       if(extraBits) 
+               nShifts++;
+               
+       return nShifts;
+}
+
+/* Function to return the number of shifts to get a 1 in bit 0
+ */
+ 
+static __u32 ShiftDiv(__u32 x)
+{
+       int nShifts;
+       
+       nShifts =  0;
+       
+       if(!x) return 0;
+       
+       while( !(x&1)){
+               x>>=1;
+               nShifts++;
+       }
+               
+       return nShifts;
+}
+
+
+
+/* 
+ * Temporary buffer manipulations.
+ */
+
+static int yaffs_InitialiseTempBuffers(yaffs_Device *dev)      
+{
+       int i;
+       __u8 *buf = (__u8 *)1;
+               
+       memset(dev->tempBuffer,0,sizeof(dev->tempBuffer));
+               
+       for (i = 0; buf && i < YAFFS_N_TEMP_BUFFERS; i++) {
+               dev->tempBuffer[i].line = 0;    /* not in use */
+               dev->tempBuffer[i].buffer = buf =
+                   YMALLOC_DMA(dev->nDataBytesPerChunk);
+       }
+               
+       return buf ? YAFFS_OK : YAFFS_FAIL;
+       
+}
+
+static __u8 *yaffs_GetTempBuffer(yaffs_Device * dev, int lineNo)
+{
+       int i, j;
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               if (dev->tempBuffer[i].line == 0) {
+                       dev->tempBuffer[i].line = lineNo;
+                       if ((i + 1) > dev->maxTemp) {
+                               dev->maxTemp = i + 1;
+                               for (j = 0; j <= i; j++)
+                                       dev->tempBuffer[j].maxLine =
+                                           dev->tempBuffer[j].line;
+                       }
+
+                       return dev->tempBuffer[i].buffer;
+               }
+       }
+
+       T(YAFFS_TRACE_BUFFERS,
+         (TSTR("Out of temp buffers at line %d, other held by lines:"),
+          lineNo));
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               T(YAFFS_TRACE_BUFFERS, (TSTR(" %d "), dev->tempBuffer[i].line));
+       }
+       T(YAFFS_TRACE_BUFFERS, (TSTR(" " TENDSTR)));
+
+       /*
+        * If we got here then we have to allocate an unmanaged one
+        * This is not good.
+        */
+
+       dev->unmanagedTempAllocations++;
+       return YMALLOC(dev->nDataBytesPerChunk);
+
+}
+
+static void yaffs_ReleaseTempBuffer(yaffs_Device * dev, __u8 * buffer,
+                                   int lineNo)
+{
+       int i;
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               if (dev->tempBuffer[i].buffer == buffer) {
+                       dev->tempBuffer[i].line = 0;
+                       return;
+               }
+       }
+
+       if (buffer) {
+               /* assume it is an unmanaged one. */
+               T(YAFFS_TRACE_BUFFERS,
+                 (TSTR("Releasing unmanaged temp buffer in line %d" TENDSTR),
+                  lineNo));
+               YFREE(buffer);
+               dev->unmanagedTempDeallocations++;
+       }
+
+}
+
+/*
+ * Determine if we have a managed buffer.
+ */
+int yaffs_IsManagedTempBuffer(yaffs_Device * dev, const __u8 * buffer)
+{
+       int i;
+       for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+               if (dev->tempBuffer[i].buffer == buffer)
+                       return 1;
+
+       }
+
+    for (i = 0; i < dev->nShortOpCaches; i++) {
+        if( dev->srCache[i].data == buffer )
+            return 1;
+
+    }
+
+    if (buffer == dev->checkpointBuffer)
+      return 1;
+
+    T(YAFFS_TRACE_ALWAYS,
+         (TSTR("yaffs: unmaged buffer detected.\n" TENDSTR)));
+    return 0;
+}
+
+
+
+/*
+ * Chunk bitmap manipulations
+ */
+
+static Y_INLINE __u8 *yaffs_BlockBits(yaffs_Device * dev, int blk)
+{
+       if (blk < dev->internalStartBlock || blk > dev->internalEndBlock) {
+               T(YAFFS_TRACE_ERROR,
+                 (TSTR("**>> yaffs: BlockBits block %d is not valid" TENDSTR),
+                  blk));
+               YBUG();
+       }
+       return dev->chunkBits +
+           (dev->chunkBitmapStride * (blk - dev->internalStartBlock));
+}
+
+static Y_INLINE void yaffs_VerifyChunkBitId(yaffs_Device *dev, int blk, int chunk)
+{
+       if(blk < dev->internalStartBlock || blk > dev->internalEndBlock ||
+          chunk < 0 || chunk >= dev->nChunksPerBlock) {
+          T(YAFFS_TRACE_ERROR,
+           (TSTR("**>> yaffs: Chunk Id (%d:%d) invalid"TENDSTR),blk,chunk));
+           YBUG();
+       }
+}
+
+static Y_INLINE void yaffs_ClearChunkBits(yaffs_Device * dev, int blk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+
+       memset(blkBits, 0, dev->chunkBitmapStride);
+}
+
+static Y_INLINE void yaffs_ClearChunkBit(yaffs_Device * dev, int blk, int chunk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+
+       yaffs_VerifyChunkBitId(dev,blk,chunk);
+
+       blkBits[chunk / 8] &= ~(1 << (chunk & 7));
+}
+
+static Y_INLINE void yaffs_SetChunkBit(yaffs_Device * dev, int blk, int chunk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       
+       yaffs_VerifyChunkBitId(dev,blk,chunk);
+
+       blkBits[chunk / 8] |= (1 << (chunk & 7));
+}
+
+static Y_INLINE int yaffs_CheckChunkBit(yaffs_Device * dev, int blk, int chunk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       yaffs_VerifyChunkBitId(dev,blk,chunk);
+
+       return (blkBits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
+}
+
+static Y_INLINE int yaffs_StillSomeChunkBits(yaffs_Device * dev, int blk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       int i;
+       for (i = 0; i < dev->chunkBitmapStride; i++) {
+               if (*blkBits)
+                       return 1;
+               blkBits++;
+       }
+       return 0;
+}
+
+static int yaffs_CountChunkBits(yaffs_Device * dev, int blk)
+{
+       __u8 *blkBits = yaffs_BlockBits(dev, blk);
+       int i;
+       int n = 0;
+       for (i = 0; i < dev->chunkBitmapStride; i++) {
+               __u8 x = *blkBits;
+               while(x){
+                       if(x & 1)
+                               n++;
+                       x >>=1;
+               }
+                       
+               blkBits++;
+       }
+       return n;
+}
+
+/* 
+ * Verification code
+ */
+ 
+static int yaffs_SkipVerification(yaffs_Device *dev)
+{
+       return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY | YAFFS_TRACE_VERIFY_FULL));
+}
+
+static int yaffs_SkipFullVerification(yaffs_Device *dev)
+{
+       return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_FULL));
+}
+
+static int yaffs_SkipNANDVerification(yaffs_Device *dev)
+{
+       return !(yaffs_traceMask & (YAFFS_TRACE_VERIFY_NAND));
+}
+
+static const char * blockStateName[] = {
+"Unknown",
+"Needs scanning",
+"Scanning",
+"Empty",
+"Allocating",
+"Full",
+"Dirty",
+"Checkpoint",
+"Collecting",
+"Dead"
+};
+
+static void yaffs_VerifyBlock(yaffs_Device *dev,yaffs_BlockInfo *bi,int n)
+{
+       int actuallyUsed;
+       int inUse;
+       
+       if(yaffs_SkipVerification(dev))
+               return;
+               
+       /* Report illegal runtime states */
+       if(bi->blockState <0 || bi->blockState >= YAFFS_NUMBER_OF_BLOCK_STATES)
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has undefined state %d"TENDSTR),n,bi->blockState));
+               
+       switch(bi->blockState){
+        case YAFFS_BLOCK_STATE_UNKNOWN:
+        case YAFFS_BLOCK_STATE_SCANNING:
+        case YAFFS_BLOCK_STATE_NEEDS_SCANNING:
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has bad run-state %s"TENDSTR),
+               n,blockStateName[bi->blockState]));
+       }
+       
+       /* Check pages in use and soft deletions are legal */
+       
+       actuallyUsed = bi->pagesInUse - bi->softDeletions;
+       
+       if(bi->pagesInUse < 0 || bi->pagesInUse > dev->nChunksPerBlock ||
+          bi->softDeletions < 0 || bi->softDeletions > dev->nChunksPerBlock ||
+          actuallyUsed < 0 || actuallyUsed > dev->nChunksPerBlock)
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has illegal values pagesInUsed %d softDeletions %d"TENDSTR),
+               n,bi->pagesInUse,bi->softDeletions));
+       
+               
+       /* Check chunk bitmap legal */
+       inUse = yaffs_CountChunkBits(dev,n);
+       if(inUse != bi->pagesInUse)
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has inconsistent values pagesInUse %d counted chunk bits %d"TENDSTR),
+                       n,bi->pagesInUse,inUse));
+       
+       /* Check that the sequence number is valid.
+        * Ten million is legal, but is very unlikely 
+        */
+       if(dev->isYaffs2 && 
+          (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING || bi->blockState == YAFFS_BLOCK_STATE_FULL) &&
+          (bi->sequenceNumber < YAFFS_LOWEST_SEQUENCE_NUMBER || bi->sequenceNumber > 10000000 ))
+               T(YAFFS_TRACE_VERIFY,(TSTR("Block %d has suspect sequence number of %d"TENDSTR),
+               n,bi->sequenceNumber));
+               
+}
+
+static void yaffs_VerifyCollectedBlock(yaffs_Device *dev,yaffs_BlockInfo *bi,int n)
+{
+       yaffs_VerifyBlock(dev,bi,n);
+       
+       /* After collection the block should be in the erased state */
+       /* TODO: This will need to change if we do partial gc */
+       
+       if(bi->blockState != YAFFS_BLOCK_STATE_EMPTY){
+               T(YAFFS_TRACE_ERROR,(TSTR("Block %d is in state %d after gc, should be erased"TENDSTR),
+                       n,bi->blockState));
+       }
+}
+
+static void yaffs_VerifyBlocks(yaffs_Device *dev)
+{
+       int i;
+       int nBlocksPerState[YAFFS_NUMBER_OF_BLOCK_STATES];
+       int nIllegalBlockStates = 0;
+       
+
+       if(yaffs_SkipVerification(dev))
+               return;
+
+       memset(nBlocksPerState,0,sizeof(nBlocksPerState));
+
+               
+       for(i = dev->internalStartBlock; i <= dev->internalEndBlock; i++){
+               yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev,i);
+               yaffs_VerifyBlock(dev,bi,i);
+
+               if(bi->blockState >=0 && bi->blockState < YAFFS_NUMBER_OF_BLOCK_STATES)
+                       nBlocksPerState[bi->blockState]++;
+               else
+                       nIllegalBlockStates++;
+                                       
+       }
+       
+       T(YAFFS_TRACE_VERIFY,(TSTR(""TENDSTR)));
+       T(YAFFS_TRACE_VERIFY,(TSTR("Block summary"TENDSTR)));
+       
+       T(YAFFS_TRACE_VERIFY,(TSTR("%d blocks have illegal states"TENDSTR),nIllegalBlockStates));
+       if(nBlocksPerState[YAFFS_BLOCK_STATE_ALLOCATING] > 1)
+               T(YAFFS_TRACE_VERIFY,(TSTR("Too many allocating blocks"TENDSTR)));
+
+       for(i = 0; i < YAFFS_NUMBER_OF_BLOCK_STATES; i++)
+               T(YAFFS_TRACE_VERIFY,
+                 (TSTR("%s %d blocks"TENDSTR),
+                 blockStateName[i],nBlocksPerState[i]));
+       
+       if(dev->blocksInCheckpoint != nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT])
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Checkpoint block count wrong dev %d count %d"TENDSTR),
+                dev->blocksInCheckpoint, nBlocksPerState[YAFFS_BLOCK_STATE_CHECKPOINT]));
+                
+       if(dev->nErasedBlocks != nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY])
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Erased block count wrong dev %d count %d"TENDSTR),
+                dev->nErasedBlocks, nBlocksPerState[YAFFS_BLOCK_STATE_EMPTY]));
+                
+       if(nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING] > 1)
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Too many collecting blocks %d (max is 1)"TENDSTR),
+                nBlocksPerState[YAFFS_BLOCK_STATE_COLLECTING]));
+
+       T(YAFFS_TRACE_VERIFY,(TSTR(""TENDSTR)));
+
+}
+
+/*
+ * Verify the object header. oh must be valid, but obj and tags may be NULL in which
+ * case those tests will not be performed.
+ */
+static void yaffs_VerifyObjectHeader(yaffs_Object *obj, yaffs_ObjectHeader *oh, yaffs_ExtendedTags *tags, int parentCheck)
+{
+       if(yaffs_SkipVerification(obj->myDev))
+               return;
+               
+       if(!(tags && obj && oh)){
+               T(YAFFS_TRACE_VERIFY,
+                               (TSTR("Verifying object header tags %x obj %x oh %x"TENDSTR),
+                               (__u32)tags,(__u32)obj,(__u32)oh));
+               return;
+       }
+       
+       if(oh->type <= YAFFS_OBJECT_TYPE_UNKNOWN ||
+          oh->type > YAFFS_OBJECT_TYPE_MAX)
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Obj %d header type is illegal value 0x%x"TENDSTR),
+                tags->objectId, oh->type));
+
+       if(tags->objectId != obj->objectId)
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Obj %d header mismatch objectId %d"TENDSTR),
+                tags->objectId, obj->objectId));
+
+
+       /*
+        * Check that the object's parent ids match if parentCheck requested.
+        * 
+        * Tests do not apply to the root object.
+        */
+       
+       if(parentCheck && tags->objectId > 1 && !obj->parent)
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Obj %d header mismatch parentId %d obj->parent is NULL"TENDSTR),
+                tags->objectId, oh->parentObjectId));
+               
+       
+       if(parentCheck && obj->parent &&
+          oh->parentObjectId != obj->parent->objectId && 
+          (oh->parentObjectId != YAFFS_OBJECTID_UNLINKED ||
+           obj->parent->objectId != YAFFS_OBJECTID_DELETED))
+               T(YAFFS_TRACE_VERIFY,
+                (TSTR("Obj %d header mismatch parentId %d parentObjectId %d"TENDSTR),
+                tags->objectId, oh->parentObjectId, obj->parent->objectId));
+               
+       
+       if(tags->objectId > 1 && oh->name[0] == 0) /* Null name */
+               T(YAFFS_TRACE_VERIFY,
+               (TSTR("Obj %d header name is NULL"TENDSTR),
+                obj->objectId));
+
+       if(tags->objectId > 1 && ((__u8)(oh->name[0])) == 0xff) /* Trashed name */
+               T(YAFFS_TRACE_VERIFY,
+               (TSTR("Obj %d header name is 0xFF"TENDSTR),
+                obj->objectId));
+}
+
+
+
+static int yaffs_VerifyTnodeWorker(yaffs_Object * obj, yaffs_Tnode * tn,
+                                       __u32 level, int chunkOffset)
+{
+       int i;
+       yaffs_Device *dev = obj->myDev;
+       int ok = 1;
+       int nTnodeBytes = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
+
+       if (tn) {
+               if (level > 0) {
+
+                       for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++){
+                               if (tn->internal[i]) {
+                                       ok = yaffs_VerifyTnodeWorker(obj,
+                                                       tn->internal[i],
+                                                       level - 1,
+                                                       (chunkOffset<<YAFFS_TNODES_INTERNAL_BITS) + i);
+                               }
+                       }
+               } else if (level == 0) {
+                       int i;
+                       yaffs_ExtendedTags tags;
+                       __u32 objectId = obj->objectId;
+                       
+                       chunkOffset <<=  YAFFS_TNODES_LEVEL0_BITS;
+                       
+                       for(i = 0; i < YAFFS_NTNODES_LEVEL0; i++){
+                               __u32 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
+                               
+                               if(theChunk > 0){
+                                       /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),tags.objectId,tags.chunkId,theChunk)); */
+                                       yaffs_ReadChunkWithTagsFromNAND(dev,theChunk,NULL, &tags);
+                                       if(tags.objectId != objectId || tags.chunkId != chunkOffset){
+                                               T(~0,(TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
+                                                       objectId, chunkOffset, theChunk,
+                                                       tags.objectId, tags.chunkId));
+                                       }
+                               }
+                               chunkOffset++;
+                       }
+               }
+       }
+
+       return ok;
+
+}
+
+
+static void yaffs_VerifyFile(yaffs_Object *obj)
+{
+       int requiredTallness;
+       int actualTallness;
+       __u32 lastChunk;
+       __u32 x;
+       __u32 i;
+       int ok;
+       yaffs_Device *dev;
+       yaffs_ExtendedTags tags;
+       yaffs_Tnode *tn;
+       __u32 objectId;
+       
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+       
+       dev = obj->myDev;
+       objectId = obj->objectId;
+       
+       /* Check file size is consistent with tnode depth */
+       lastChunk =  obj->variant.fileVariant.fileSize / dev->nDataBytesPerChunk + 1;
+       x = lastChunk >> YAFFS_TNODES_LEVEL0_BITS;
+       requiredTallness = 0;
+       while (x> 0) {
+               x >>= YAFFS_TNODES_INTERNAL_BITS;
+               requiredTallness++;
+       }
+       
+       actualTallness = obj->variant.fileVariant.topLevel;
+       
+       if(requiredTallness > actualTallness )
+               T(YAFFS_TRACE_VERIFY,
+               (TSTR("Obj %d had tnode tallness %d, needs to be %d"TENDSTR),
+                obj->objectId,actualTallness, requiredTallness));
+       
+       
+       /* Check that the chunks in the tnode tree are all correct. 
+        * We do this by scanning through the tnode tree and
+        * checking the tags for every chunk match.
+        */
+
+       if(yaffs_SkipNANDVerification(dev))
+               return;
+               
+       for(i = 1; i <= lastChunk; i++){
+               tn = yaffs_FindLevel0Tnode(dev, &obj->variant.fileVariant,i);
+
+               if (tn) {
+                       __u32 theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
+                       if(theChunk > 0){
+                               /* T(~0,(TSTR("verifying (%d:%d) %d"TENDSTR),objectId,i,theChunk)); */
+                               yaffs_ReadChunkWithTagsFromNAND(dev,theChunk,NULL, &tags);
+                               if(tags.objectId != objectId || tags.chunkId != i){
+                                       T(~0,(TSTR("Object %d chunkId %d NAND mismatch chunk %d tags (%d:%d)"TENDSTR),
+                                               objectId, i, theChunk,
+                                               tags.objectId, tags.chunkId));
+                               }
+                       }
+               }
+
+       }
+
+}
+
+static void yaffs_VerifyDirectory(yaffs_Object *obj)
+{
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+       
+}
+
+static void yaffs_VerifyHardLink(yaffs_Object *obj)
+{
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+               
+       /* Verify sane equivalent object */
+}
+
+static void yaffs_VerifySymlink(yaffs_Object *obj)
+{
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+               
+       /* Verify symlink string */
+}
+
+static void yaffs_VerifySpecial(yaffs_Object *obj)
+{
+       if(obj && yaffs_SkipVerification(obj->myDev))
+               return;
+}
+
+static void yaffs_VerifyObject(yaffs_Object *obj)
+{
+       yaffs_Device *dev;
+       
+       __u32 chunkMin;
+       __u32 chunkMax;
+       
+       __u32 chunkIdOk;
+       __u32 chunkIsLive;
+       
+       if(!obj)
+               return;
+       
+       dev = obj->myDev;
+       
+       if(yaffs_SkipVerification(dev))
+               return;
+               
+       /* Check sane object header chunk */
+       
+       chunkMin = dev->internalStartBlock * dev->nChunksPerBlock;
+       chunkMax = (dev->internalEndBlock+1) * dev->nChunksPerBlock - 1;
+       
+       chunkIdOk = (obj->chunkId >= chunkMin && obj->chunkId <= chunkMax);
+       chunkIsLive = chunkIdOk && 
+                       yaffs_CheckChunkBit(dev, 
+                                           obj->chunkId / dev->nChunksPerBlock,
+                                           obj->chunkId % dev->nChunksPerBlock);
+       if(!obj->fake && 
+           (!chunkIdOk || !chunkIsLive)) {
+          T(YAFFS_TRACE_VERIFY,
+          (TSTR("Obj %d has chunkId %d %s %s"TENDSTR),
+          obj->objectId,obj->chunkId,
+          chunkIdOk ? "" : ",out of range",
+          chunkIsLive || !chunkIdOk ? "" : ",marked as deleted"));
+       }
+       
+       if(chunkIdOk && chunkIsLive &&!yaffs_SkipNANDVerification(dev)) {
+               yaffs_ExtendedTags tags;
+               yaffs_ObjectHeader *oh;
+               __u8 *buffer = yaffs_GetTempBuffer(dev,__LINE__);
+               
+               oh = (yaffs_ObjectHeader *)buffer;
+               
+               yaffs_ReadChunkWithTagsFromNAND(dev, obj->chunkId,buffer, &tags);
+               
+               yaffs_VerifyObjectHeader(obj,oh,&tags,1);
+               
+               yaffs_ReleaseTempBuffer(dev,buffer,__LINE__);
+       }
+       
+       /* Verify it has a parent */
+       if(obj && !obj->fake &&
+          (!obj->parent || obj->parent->myDev != dev)){
+          T(YAFFS_TRACE_VERIFY,
+          (TSTR("Obj %d has parent pointer %p which does not look like an object"TENDSTR),
+          obj->objectId,obj->parent));    
+       }
+       
+       /* Verify parent is a directory */
+       if(obj->parent && obj->parent->variantType != YAFFS_OBJECT_TYPE_DIRECTORY){
+          T(YAFFS_TRACE_VERIFY,
+          (TSTR("Obj %d's parent is not a directory (type %d)"TENDSTR),
+          obj->objectId,obj->parent->variantType));       
+       }
+       
+       switch(obj->variantType){
+       case YAFFS_OBJECT_TYPE_FILE:
+               yaffs_VerifyFile(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               yaffs_VerifySymlink(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_DIRECTORY:
+               yaffs_VerifyDirectory(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_HARDLINK:
+               yaffs_VerifyHardLink(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SPECIAL:
+               yaffs_VerifySpecial(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_UNKNOWN:
+       default:
+               T(YAFFS_TRACE_VERIFY,
+               (TSTR("Obj %d has illegaltype %d"TENDSTR),
+               obj->objectId,obj->variantType));          
+               break;
+       }
+       
+       
+}
+
+static void yaffs_VerifyObjects(yaffs_Device *dev)
+{
+       yaffs_Object *obj;
+       int i;
+       struct list_head *lh;
+
+       if(yaffs_SkipVerification(dev))
+               return;
+       
+       /* Iterate through the objects in each hash entry */
+        
+        for(i = 0; i <  YAFFS_NOBJECT_BUCKETS; i++){
+               list_for_each(lh, &dev->objectBucket[i].list) {
+                       if (lh) {
+                               obj = list_entry(lh, yaffs_Object, hashLink);
+                               yaffs_VerifyObject(obj);
+                       }
+               }
+        }
+
+}
+
+
+/*
+ *  Simple hash function. Needs to have a reasonable spread
+ */
+ 
+static Y_INLINE int yaffs_HashFunction(int n)
+{
+       n = abs(n);
+       return (n % YAFFS_NOBJECT_BUCKETS);
+}
+
+/*
+ * Access functions to useful fake objects
+ */
+ 
+yaffs_Object *yaffs_Root(yaffs_Device * dev)
+{
+       return dev->rootDir;
+}
+
+yaffs_Object *yaffs_LostNFound(yaffs_Device * dev)
+{
+       return dev->lostNFoundDir;
+}
+
+
+/*
+ *  Erased NAND checking functions
+ */
+ 
+int yaffs_CheckFF(__u8 * buffer, int nBytes)
+{
+       /* Horrible, slow implementation */
+       while (nBytes--) {
+               if (*buffer != 0xFF)
+                       return 0;
+               buffer++;
+       }
+       return 1;
+}
+
+static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
+                                 int chunkInNAND)
+{
+
+       int retval = YAFFS_OK;
+       __u8 *data = yaffs_GetTempBuffer(dev, __LINE__);
+       yaffs_ExtendedTags tags;
+       int result;
+
+       result = yaffs_ReadChunkWithTagsFromNAND(dev, chunkInNAND, data, &tags);
+       
+       if(tags.eccResult > YAFFS_ECC_RESULT_NO_ERROR)
+               retval = YAFFS_FAIL;
+               
+
+       if (!yaffs_CheckFF(data, dev->nDataBytesPerChunk) || tags.chunkUsed) {
+               T(YAFFS_TRACE_NANDACCESS,
+                 (TSTR("Chunk %d not erased" TENDSTR), chunkInNAND));
+               retval = YAFFS_FAIL;
+       }
+
+       yaffs_ReleaseTempBuffer(dev, data, __LINE__);
+
+       return retval;
+
+}
+
+
+static int yaffs_WriteNewChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
+                                            const __u8 * data,
+                                            yaffs_ExtendedTags * tags,
+                                            int useReserve)
+{
+       int attempts = 0;
+       int writeOk = 0;
+       int chunk;
+
+       yaffs_InvalidateCheckpoint(dev);
+
+       do {
+               yaffs_BlockInfo *bi = 0;
+               int erasedOk = 0;
+
+               chunk = yaffs_AllocateChunk(dev, useReserve, &bi);
+               if (chunk < 0) {
+                       /* no space */
+                       break;
+               }
+
+               /* First check this chunk is erased, if it needs
+                * checking.  The checking policy (unless forced
+                * always on) is as follows:
+                *
+                * Check the first page we try to write in a block.
+                * If the check passes then we don't need to check any
+                * more.        If the check fails, we check again...
+                * If the block has been erased, we don't need to check.
+                *
+                * However, if the block has been prioritised for gc,
+                * then we think there might be something odd about
+                * this block and stop using it.
+                *
+                * Rationale: We should only ever see chunks that have
+                * not been erased if there was a partially written
+                * chunk due to power loss.  This checking policy should
+                * catch that case with very few checks and thus save a
+                * lot of checks that are most likely not needed.
+                */
+               if (bi->gcPrioritise) {
+                       yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
+                       /* try another chunk */
+                       continue;
+               }
+
+               /* let's give it a try */
+               attempts++;
+
+#ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
+               bi->skipErasedCheck = 0;
+#endif
+               if (!bi->skipErasedCheck) {
+                       erasedOk = yaffs_CheckChunkErased(dev, chunk);
+                       if (erasedOk != YAFFS_OK) {
+                               T(YAFFS_TRACE_ERROR,
+                               (TSTR ("**>> yaffs chunk %d was not erased"
+                               TENDSTR), chunk));
+
+                               /* try another chunk */
+                               continue;
+                       }
+                       bi->skipErasedCheck = 1;
+               }
+
+               writeOk = yaffs_WriteChunkWithTagsToNAND(dev, chunk,
+                               data, tags);
+               if (writeOk != YAFFS_OK) {
+                       yaffs_HandleWriteChunkError(dev, chunk, erasedOk);
+                       /* try another chunk */
+                       continue;
+               }
+
+               /* Copy the data into the robustification buffer */
+               yaffs_HandleWriteChunkOk(dev, chunk, data, tags);
+
+       } while (writeOk != YAFFS_OK && attempts < yaffs_wr_attempts);
+
+       if (attempts > 1) {
+               T(YAFFS_TRACE_ERROR,
+                       (TSTR("**>> yaffs write required %d attempts" TENDSTR),
+                       attempts));
+
+               dev->nRetriedWrites += (attempts - 1);
+       }
+
+       return chunk;
+}
+
+/*
+ * Block retiring for handling a broken block.
+ */
+ 
+static void yaffs_RetireBlock(yaffs_Device * dev, int blockInNAND)
+{
+       yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
+
+       yaffs_InvalidateCheckpoint(dev);
+       
+       yaffs_MarkBlockBad(dev, blockInNAND);
+
+       bi->blockState = YAFFS_BLOCK_STATE_DEAD;
+       bi->gcPrioritise = 0;
+       bi->needsRetiring = 0;
+
+       dev->nRetiredBlocks++;
+}
+
+/*
+ * Functions for robustisizing TODO
+ *
+ */
+ 
+static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
+                                    const __u8 * data,
+                                    const yaffs_ExtendedTags * tags)
+{
+}
+
+static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
+                                   const yaffs_ExtendedTags * tags)
+{
+}
+
+void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi)
+{
+       if(!bi->gcPrioritise){
+               bi->gcPrioritise = 1;
+               dev->hasPendingPrioritisedGCs = 1;
+               bi->chunkErrorStrikes ++;
+               
+               if(bi->chunkErrorStrikes > 3){
+                       bi->needsRetiring = 1; /* Too many stikes, so retire this */
+                       T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Block struck out" TENDSTR)));
+
+               }
+               
+       }
+}
+
+static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND, int erasedOk)
+{
+
+       int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
+       yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockInNAND);
+
+       yaffs_HandleChunkError(dev,bi);
+               
+       
+       if(erasedOk ) {
+               /* Was an actual write failure, so mark the block for retirement  */
+               bi->needsRetiring = 1;
+               T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                 (TSTR("**>> Block %d needs retiring" TENDSTR), blockInNAND));
+
+               
+       }
+       
+       /* Delete the chunk */
+       yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
+}
+
+
+/*---------------- Name handling functions ------------*/ 
+
+static __u16 yaffs_CalcNameSum(const YCHAR * name)
+{
+       __u16 sum = 0;
+       __u16 i = 1;
+
+       YUCHAR *bname = (YUCHAR *) name;
+       if (bname) {
+               while ((*bname) && (i < (YAFFS_MAX_NAME_LENGTH/2))) {
+
+#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
+                       sum += yaffs_toupper(*bname) * i;
+#else
+                       sum += (*bname) * i;
+#endif
+                       i++;
+                       bname++;
+               }
+       }
+       return sum;
+}
+
+static void yaffs_SetObjectName(yaffs_Object * obj, const YCHAR * name)
+{
+#ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
+       if (name && yaffs_strlen(name) <= YAFFS_SHORT_NAME_LENGTH) {
+               yaffs_strcpy(obj->shortName, name);
+       } else {
+               obj->shortName[0] = _Y('\0');
+       }
+#endif
+       obj->sum = yaffs_CalcNameSum(name);
+}
+
+/*-------------------- TNODES -------------------
+
+ * List of spare tnodes
+ * The list is hooked together using the first pointer
+ * in the tnode.
+ */
+ 
+/* yaffs_CreateTnodes creates a bunch more tnodes and
+ * adds them to the tnode free list.
+ * Don't use this function directly
+ */
+
+static int yaffs_CreateTnodes(yaffs_Device * dev, int nTnodes)
+{
+       int i;
+       int tnodeSize;
+       yaffs_Tnode *newTnodes;
+       __u8 *mem;
+       yaffs_Tnode *curr;
+       yaffs_Tnode *next;
+       yaffs_TnodeList *tnl;
+
+       if (nTnodes < 1)
+               return YAFFS_OK;
+               
+       /* Calculate the tnode size in bytes for variable width tnode support.
+        * Must be a multiple of 32-bits  */
+       tnodeSize = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
+
+       /* make these things */
+
+       newTnodes = YMALLOC(nTnodes * tnodeSize);
+       mem = (__u8 *)newTnodes;
+
+       if (!newTnodes) {
+               T(YAFFS_TRACE_ERROR,
+                 (TSTR("yaffs: Could not allocate Tnodes" TENDSTR)));
+               return YAFFS_FAIL;
+       }
+
+       /* Hook them into the free list */
+#if 0
+       for (i = 0; i < nTnodes - 1; i++) {
+               newTnodes[i].internal[0] = &newTnodes[i + 1];
+#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
+               newTnodes[i].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
+#endif
+       }
+
+       newTnodes[nTnodes - 1].internal[0] = dev->freeTnodes;
+#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
+       newTnodes[nTnodes - 1].internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
+#endif
+       dev->freeTnodes = newTnodes;
+#else
+       /* New hookup for wide tnodes */
+       for(i = 0; i < nTnodes -1; i++) {
+               curr = (yaffs_Tnode *) &mem[i * tnodeSize];
+               next = (yaffs_Tnode *) &mem[(i+1) * tnodeSize];
+               curr->internal[0] = next;
+       }
+       
+       curr = (yaffs_Tnode *) &mem[(nTnodes - 1) * tnodeSize];
+       curr->internal[0] = dev->freeTnodes;
+       dev->freeTnodes = (yaffs_Tnode *)mem;
+
+#endif
+
+
+       dev->nFreeTnodes += nTnodes;
+       dev->nTnodesCreated += nTnodes;
+
+       /* Now add this bunch of tnodes to a list for freeing up.
+        * NB If we can't add this to the management list it isn't fatal
+        * but it just means we can't free this bunch of tnodes later.
+        */
+        
+       tnl = YMALLOC(sizeof(yaffs_TnodeList));
+       if (!tnl) {
+               T(YAFFS_TRACE_ERROR,
+                 (TSTR
+                  ("yaffs: Could not add tnodes to management list" TENDSTR)));
+                  return YAFFS_FAIL;
+
+       } else {
+               tnl->tnodes = newTnodes;
+               tnl->next = dev->allocatedTnodeList;
+               dev->allocatedTnodeList = tnl;
+       }
+
+       T(YAFFS_TRACE_ALLOCATE, (TSTR("yaffs: Tnodes added" TENDSTR)));
+
+       return YAFFS_OK;
+}
+
+/* GetTnode gets us a clean tnode. Tries to make allocate more if we run out */
+
+static yaffs_Tnode *yaffs_GetTnodeRaw(yaffs_Device * dev)
+{
+       yaffs_Tnode *tn = NULL;
+
+       /* If there are none left make more */
+       if (!dev->freeTnodes) {
+               yaffs_CreateTnodes(dev, YAFFS_ALLOCATION_NTNODES);
+       }
+
+       if (dev->freeTnodes) {
+               tn = dev->freeTnodes;
+#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
+               if (tn->internal[YAFFS_NTNODES_INTERNAL] != (void *)1) {
+                       /* Hoosterman, this thing looks like it isn't in the list */
+                       T(YAFFS_TRACE_ALWAYS,
+                         (TSTR("yaffs: Tnode list bug 1" TENDSTR)));
+               }
+#endif
+               dev->freeTnodes = dev->freeTnodes->internal[0];
+               dev->nFreeTnodes--;
+       }
+
+       return tn;
+}
+
+static yaffs_Tnode *yaffs_GetTnode(yaffs_Device * dev)
+{
+       yaffs_Tnode *tn = yaffs_GetTnodeRaw(dev);
+       
+       if(tn)
+               memset(tn, 0, (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);
+
+       return tn;      
+}
+
+/* FreeTnode frees up a tnode and puts it back on the free list */
+static void yaffs_FreeTnode(yaffs_Device * dev, yaffs_Tnode * tn)
+{
+       if (tn) {
+#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
+               if (tn->internal[YAFFS_NTNODES_INTERNAL] != 0) {
+                       /* Hoosterman, this thing looks like it is already in the list */
+                       T(YAFFS_TRACE_ALWAYS,
+                         (TSTR("yaffs: Tnode list bug 2" TENDSTR)));
+               }
+               tn->internal[YAFFS_NTNODES_INTERNAL] = (void *)1;
+#endif
+               tn->internal[0] = dev->freeTnodes;
+               dev->freeTnodes = tn;
+               dev->nFreeTnodes++;
+       }
+}
+
+static void yaffs_DeinitialiseTnodes(yaffs_Device * dev)
+{
+       /* Free the list of allocated tnodes */
+       yaffs_TnodeList *tmp;
+
+       while (dev->allocatedTnodeList) {
+               tmp = dev->allocatedTnodeList->next;
+
+               YFREE(dev->allocatedTnodeList->tnodes);
+               YFREE(dev->allocatedTnodeList);
+               dev->allocatedTnodeList = tmp;
+
+       }
+
+       dev->freeTnodes = NULL;
+       dev->nFreeTnodes = 0;
+}
+
+static void yaffs_InitialiseTnodes(yaffs_Device * dev)
+{
+       dev->allocatedTnodeList = NULL;
+       dev->freeTnodes = NULL;
+       dev->nFreeTnodes = 0;
+       dev->nTnodesCreated = 0;
+
+}
+
+
+void yaffs_PutLevel0Tnode(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos, unsigned val)
+{
+  __u32 *map = (__u32 *)tn;
+  __u32 bitInMap;
+  __u32 bitInWord;
+  __u32 wordInMap;
+  __u32 mask;
+  
+  pos &= YAFFS_TNODES_LEVEL0_MASK;
+  val >>= dev->chunkGroupBits;
+  
+  bitInMap = pos * dev->tnodeWidth;
+  wordInMap = bitInMap /32;
+  bitInWord = bitInMap & (32 -1);
+  
+  mask = dev->tnodeMask << bitInWord;
+  
+  map[wordInMap] &= ~mask;
+  map[wordInMap] |= (mask & (val << bitInWord));
+  
+  if(dev->tnodeWidth > (32-bitInWord)) {
+    bitInWord = (32 - bitInWord);
+    wordInMap++;;
+    mask = dev->tnodeMask >> (/*dev->tnodeWidth -*/ bitInWord);
+    map[wordInMap] &= ~mask;
+    map[wordInMap] |= (mask & (val >> bitInWord));
+  }
+}
+
+static __u32 yaffs_GetChunkGroupBase(yaffs_Device *dev, yaffs_Tnode *tn, unsigned pos)
+{
+  __u32 *map = (__u32 *)tn;
+  __u32 bitInMap;
+  __u32 bitInWord;
+  __u32 wordInMap;
+  __u32 val;
+  
+  pos &= YAFFS_TNODES_LEVEL0_MASK;
+  
+  bitInMap = pos * dev->tnodeWidth;
+  wordInMap = bitInMap /32;
+  bitInWord = bitInMap & (32 -1);
+  
+  val = map[wordInMap] >> bitInWord;
+  
+  if(dev->tnodeWidth > (32-bitInWord)) {
+    bitInWord = (32 - bitInWord);
+    wordInMap++;;
+    val |= (map[wordInMap] << bitInWord);
+  }
+  
+  val &= dev->tnodeMask;
+  val <<= dev->chunkGroupBits;
+  
+  return val;
+}
+
+/* ------------------- End of individual tnode manipulation -----------------*/
+
+/* ---------Functions to manipulate the look-up tree (made up of tnodes) ------
+ * The look up tree is represented by the top tnode and the number of topLevel
+ * in the tree. 0 means only the level 0 tnode is in the tree.
+ */
+
+/* FindLevel0Tnode finds the level 0 tnode, if one exists. */
+static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device * dev,
+                                         yaffs_FileStructure * fStruct,
+                                         __u32 chunkId)
+{
+
+       yaffs_Tnode *tn = fStruct->top;
+       __u32 i;
+       int requiredTallness;
+       int level = fStruct->topLevel;
+
+       /* Check sane level and chunk Id */
+       if (level < 0 || level > YAFFS_TNODES_MAX_LEVEL) {
+               return NULL;
+       }
+
+       if (chunkId > YAFFS_MAX_CHUNK_ID) {
+               return NULL;
+       }
+
+       /* First check we're tall enough (ie enough topLevel) */
+
+       i = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
+       requiredTallness = 0;
+       while (i) {
+               i >>= YAFFS_TNODES_INTERNAL_BITS;
+               requiredTallness++;
+       }
+
+       if (requiredTallness > fStruct->topLevel) {
+               /* Not tall enough, so we can't find it, return NULL. */
+               return NULL;
+       }
+
+       /* Traverse down to level 0 */
+       while (level > 0 && tn) {
+               tn = tn->
+                   internal[(chunkId >>
+                              ( YAFFS_TNODES_LEVEL0_BITS + 
+                                (level - 1) *
+                                YAFFS_TNODES_INTERNAL_BITS)
+                             ) &
+                            YAFFS_TNODES_INTERNAL_MASK];
+               level--;
+
+       }
+
+       return tn;
+}
+
+/* AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
+ * This happens in two steps:
+ *  1. If the tree isn't tall enough, then make it taller.
+ *  2. Scan down the tree towards the level 0 tnode adding tnodes if required.
+ *
+ * Used when modifying the tree.
+ *
+ *  If the tn argument is NULL, then a fresh tnode will be added otherwise the specified tn will
+ *  be plugged into the ttree.
+ */
+ 
+static yaffs_Tnode *yaffs_AddOrFindLevel0Tnode(yaffs_Device * dev,
+                                              yaffs_FileStructure * fStruct,
+                                              __u32 chunkId,
+                                              yaffs_Tnode *passedTn)
+{
+
+       int requiredTallness;
+       int i;
+       int l;
+       yaffs_Tnode *tn;
+
+       __u32 x;
+
+
+       /* Check sane level and page Id */
+       if (fStruct->topLevel < 0 || fStruct->topLevel > YAFFS_TNODES_MAX_LEVEL) {
+               return NULL;
+       }
+
+       if (chunkId > YAFFS_MAX_CHUNK_ID) {
+               return NULL;
+       }
+
+       /* First check we're tall enough (ie enough topLevel) */
+
+       x = chunkId >> YAFFS_TNODES_LEVEL0_BITS;
+       requiredTallness = 0;
+       while (x) {
+               x >>= YAFFS_TNODES_INTERNAL_BITS;
+               requiredTallness++;
+       }
+
+
+       if (requiredTallness > fStruct->topLevel) {
+               /* Not tall enough,gotta make the tree taller */
+               for (i = fStruct->topLevel; i < requiredTallness; i++) {
+               
+                       tn = yaffs_GetTnode(dev);
+
+                       if (tn) {
+                               tn->internal[0] = fStruct->top;
+                               fStruct->top = tn;
+                       } else {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR("yaffs: no more tnodes" TENDSTR)));
+                       }
+               }
+
+               fStruct->topLevel = requiredTallness;
+       }
+
+       /* Traverse down to level 0, adding anything we need */
+
+       l = fStruct->topLevel;
+       tn = fStruct->top;
+       
+       if(l > 0) {
+               while (l > 0 && tn) {
+                       x = (chunkId >>
+                            ( YAFFS_TNODES_LEVEL0_BITS +
+                             (l - 1) * YAFFS_TNODES_INTERNAL_BITS)) &
+                           YAFFS_TNODES_INTERNAL_MASK;
+
+
+                       if((l>1) && !tn->internal[x]){
+                               /* Add missing non-level-zero tnode */
+                               tn->internal[x] = yaffs_GetTnode(dev);
+
+                       } else if(l == 1) {
+                               /* Looking from level 1 at level 0 */
+                               if (passedTn) {
+                                       /* If we already have one, then release it.*/
+                                       if(tn->internal[x])
+                                               yaffs_FreeTnode(dev,tn->internal[x]);
+                                       tn->internal[x] = passedTn;
+                       
+                               } else if(!tn->internal[x]) {
+                                       /* Don't have one, none passed in */
+                                       tn->internal[x] = yaffs_GetTnode(dev);
+                               }
+                       }
+               
+                       tn = tn->internal[x];
+                       l--;
+               }
+       } else {
+               /* top is level 0 */
+               if(passedTn) {
+                       memcpy(tn,passedTn,(dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);
+                       yaffs_FreeTnode(dev,passedTn);
+               }
+       }
+
+       return tn;
+}
+
+static int yaffs_FindChunkInGroup(yaffs_Device * dev, int theChunk,
+                                 yaffs_ExtendedTags * tags, int objectId,
+                                 int chunkInInode)
+{
+       int j;
+
+       for (j = 0; theChunk && j < dev->chunkGroupSize; j++) {
+               if (yaffs_CheckChunkBit
+                   (dev, theChunk / dev->nChunksPerBlock,
+                    theChunk % dev->nChunksPerBlock)) {
+                       yaffs_ReadChunkWithTagsFromNAND(dev, theChunk, NULL,
+                                                       tags);
+                       if (yaffs_TagsMatch(tags, objectId, chunkInInode)) {
+                               /* found it; */
+                               return theChunk;
+
+                       }
+               }
+               theChunk++;
+       }
+       return -1;
+}
+
+
+/* DeleteWorker scans backwards through the tnode tree and deletes all the
+ * chunks and tnodes in the file
+ * Returns 1 if the tree was deleted. 
+ * Returns 0 if it stopped early due to hitting the limit and the delete is incomplete.
+ */
+
+static int yaffs_DeleteWorker(yaffs_Object * in, yaffs_Tnode * tn, __u32 level,
+                             int chunkOffset, int *limit)
+{
+       int i;
+       int chunkInInode;
+       int theChunk;
+       yaffs_ExtendedTags tags;
+       int foundChunk;
+       yaffs_Device *dev = in->myDev;
+
+       int allDone = 1;
+
+       if (tn) {
+               if (level > 0) {
+
+                       for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
+                            i--) {
+                               if (tn->internal[i]) {
+                                       if (limit && (*limit) < 0) {
+                                               allDone = 0;
+                                       } else {
+                                               allDone =
+                                                   yaffs_DeleteWorker(in,
+                                                                      tn->
+                                                                      internal
+                                                                      [i],
+                                                                      level -
+                                                                      1,
+                                                                      (chunkOffset
+                                                                       <<
+                                                                       YAFFS_TNODES_INTERNAL_BITS)
+                                                                      + i,
+                                                                      limit);
+                                       }
+                                       if (allDone) {
+                                               yaffs_FreeTnode(dev,
+                                                               tn->
+                                                               internal[i]);
+                                               tn->internal[i] = NULL;
+                                       }
+                               }
+
+                       }
+                       return (allDone) ? 1 : 0;
+               } else if (level == 0) {
+                       int hitLimit = 0;
+
+                       for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0 && !hitLimit;
+                            i--) {
+                               theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
+                               if (theChunk) {
+
+                                       chunkInInode =
+                                           (chunkOffset <<
+                                            YAFFS_TNODES_LEVEL0_BITS) + i;
+
+                                       foundChunk =
+                                           yaffs_FindChunkInGroup(dev,
+                                                                  theChunk,
+                                                                  &tags,
+                                                                  in->objectId,
+                                                                  chunkInInode);
+
+                                       if (foundChunk > 0) {
+                                               yaffs_DeleteChunk(dev,
+                                                                 foundChunk, 1,
+                                                                 __LINE__);
+                                               in->nDataChunks--;
+                                               if (limit) {
+                                                       *limit = *limit - 1;
+                                                       if (*limit <= 0) {
+                                                               hitLimit = 1;
+                                                       }
+                                               }
+
+                                       }
+
+                                       yaffs_PutLevel0Tnode(dev,tn,i,0);
+                               }
+
+                       }
+                       return (i < 0) ? 1 : 0;
+
+               }
+
+       }
+
+       return 1;
+
+}
+
+static void yaffs_SoftDeleteChunk(yaffs_Device * dev, int chunk)
+{
+
+       yaffs_BlockInfo *theBlock;
+
+       T(YAFFS_TRACE_DELETION, (TSTR("soft delete chunk %d" TENDSTR), chunk));
+
+       theBlock = yaffs_GetBlockInfo(dev, chunk / dev->nChunksPerBlock);
+       if (theBlock) {
+               theBlock->softDeletions++;
+               dev->nFreeChunks++;
+       }
+}
+
+/* SoftDeleteWorker scans backwards through the tnode tree and soft deletes all the chunks in the file.
+ * All soft deleting does is increment the block's softdelete count and pulls the chunk out
+ * of the tnode.
+ * Thus, essentially this is the same as DeleteWorker except that the chunks are soft deleted.
+ */
+ 
+static int yaffs_SoftDeleteWorker(yaffs_Object * in, yaffs_Tnode * tn,
+                                 __u32 level, int chunkOffset)
+{
+       int i;
+       int theChunk;
+       int allDone = 1;
+       yaffs_Device *dev = in->myDev;
+
+       if (tn) {
+               if (level > 0) {
+
+                       for (i = YAFFS_NTNODES_INTERNAL - 1; allDone && i >= 0;
+                            i--) {
+                               if (tn->internal[i]) {
+                                       allDone =
+                                           yaffs_SoftDeleteWorker(in,
+                                                                  tn->
+                                                                  internal[i],
+                                                                  level - 1,
+                                                                  (chunkOffset
+                                                                   <<
+                                                                   YAFFS_TNODES_INTERNAL_BITS)
+                                                                  + i);
+                                       if (allDone) {
+                                               yaffs_FreeTnode(dev,
+                                                               tn->
+                                                               internal[i]);
+                                               tn->internal[i] = NULL;
+                                       } else {
+                                               /* Hoosterman... how could this happen? */
+                                       }
+                               }
+                       }
+                       return (allDone) ? 1 : 0;
+               } else if (level == 0) {
+
+                       for (i = YAFFS_NTNODES_LEVEL0 - 1; i >= 0; i--) {
+                               theChunk = yaffs_GetChunkGroupBase(dev,tn,i);
+                               if (theChunk) {
+                                       /* Note this does not find the real chunk, only the chunk group.
+                                        * We make an assumption that a chunk group is not larger than 
+                                        * a block.
+                                        */
+                                       yaffs_SoftDeleteChunk(dev, theChunk);
+                                       yaffs_PutLevel0Tnode(dev,tn,i,0);
+                               }
+
+                       }
+                       return 1;
+
+               }
+
+       }
+
+       return 1;
+
+}
+
+static void yaffs_SoftDeleteFile(yaffs_Object * obj)
+{
+       if (obj->deleted &&
+           obj->variantType == YAFFS_OBJECT_TYPE_FILE && !obj->softDeleted) {
+               if (obj->nDataChunks <= 0) {
+                       /* Empty file with no duplicate object headers, just delete it immediately */
+                       yaffs_FreeTnode(obj->myDev,
+                                       obj->variant.fileVariant.top);
+                       obj->variant.fileVariant.top = NULL;
+                       T(YAFFS_TRACE_TRACING,
+                         (TSTR("yaffs: Deleting empty file %d" TENDSTR),
+                          obj->objectId));
+                       yaffs_DoGenericObjectDeletion(obj);
+               } else {
+                       yaffs_SoftDeleteWorker(obj,
+                                              obj->variant.fileVariant.top,
+                                              obj->variant.fileVariant.
+                                              topLevel, 0);
+                       obj->softDeleted = 1;
+               }
+       }
+}
+
+/* Pruning removes any part of the file structure tree that is beyond the
+ * bounds of the file (ie that does not point to chunks).
+ *
+ * A file should only get pruned when its size is reduced.
+ *
+ * Before pruning, the chunks must be pulled from the tree and the
+ * level 0 tnode entries must be zeroed out.
+ * Could also use this for file deletion, but that's probably better handled
+ * by a special case.
+ */
+
+static yaffs_Tnode *yaffs_PruneWorker(yaffs_Device * dev, yaffs_Tnode * tn,
+                                     __u32 level, int del0)
+{
+       int i;
+       int hasData;
+
+       if (tn) {
+               hasData = 0;
+
+               for (i = 0; i < YAFFS_NTNODES_INTERNAL; i++) {
+                       if (tn->internal[i] && level > 0) {
+                               tn->internal[i] =
+                                   yaffs_PruneWorker(dev, tn->internal[i],
+                                                     level - 1,
+                                                     (i == 0) ? del0 : 1);
+                       }
+
+                       if (tn->internal[i]) {
+                               hasData++;
+                       }
+               }
+
+               if (hasData == 0 && del0) {
+                       /* Free and return NULL */
+
+                       yaffs_FreeTnode(dev, tn);
+                       tn = NULL;
+               }
+
+       }
+
+       return tn;
+
+}
+
+static int yaffs_PruneFileStructure(yaffs_Device * dev,
+                                   yaffs_FileStructure * fStruct)
+{
+       int i;
+       int hasData;
+       int done = 0;
+       yaffs_Tnode *tn;
+
+       if (fStruct->topLevel > 0) {
+               fStruct->top =
+                   yaffs_PruneWorker(dev, fStruct->top, fStruct->topLevel, 0);
+
+               /* Now we have a tree with all the non-zero branches NULL but the height
+                * is the same as it was.
+                * Let's see if we can trim internal tnodes to shorten the tree.
+                * We can do this if only the 0th element in the tnode is in use 
+                * (ie all the non-zero are NULL)
+                */
+
+               while (fStruct->topLevel && !done) {
+                       tn = fStruct->top;
+
+                       hasData = 0;
+                       for (i = 1; i < YAFFS_NTNODES_INTERNAL; i++) {
+                               if (tn->internal[i]) {
+                                       hasData++;
+                               }
+                       }
+
+                       if (!hasData) {
+                               fStruct->top = tn->internal[0];
+                               fStruct->topLevel--;
+                               yaffs_FreeTnode(dev, tn);
+                       } else {
+                               done = 1;
+                       }
+               }
+       }
+
+       return YAFFS_OK;
+}
+
+/*-------------------- End of File Structure functions.-------------------*/
+
+/* yaffs_CreateFreeObjects creates a bunch more objects and
+ * adds them to the object free list.
+ */
+static int yaffs_CreateFreeObjects(yaffs_Device * dev, int nObjects)
+{
+       int i;
+       yaffs_Object *newObjects;
+       yaffs_ObjectList *list;
+
+       if (nObjects < 1)
+               return YAFFS_OK;
+
+       /* make these things */
+       newObjects = YMALLOC(nObjects * sizeof(yaffs_Object));
+       list = YMALLOC(sizeof(yaffs_ObjectList));
+
+       if (!newObjects || !list) {
+               if(newObjects)
+                       YFREE(newObjects);
+               if(list)
+                       YFREE(list);
+               T(YAFFS_TRACE_ALLOCATE,
+                 (TSTR("yaffs: Could not allocate more objects" TENDSTR)));
+               return YAFFS_FAIL;
+       }
+       
+       /* Hook them into the free list */
+       for (i = 0; i < nObjects - 1; i++) {
+               newObjects[i].siblings.next =
+                   (struct list_head *)(&newObjects[i + 1]);
+       }
+
+       newObjects[nObjects - 1].siblings.next = (void *)dev->freeObjects;
+       dev->freeObjects = newObjects;
+       dev->nFreeObjects += nObjects;
+       dev->nObjectsCreated += nObjects;
+
+       /* Now add this bunch of Objects to a list for freeing up. */
+
+       list->objects = newObjects;
+       list->next = dev->allocatedObjectList;
+       dev->allocatedObjectList = list;
+
+       return YAFFS_OK;
+}
+
+
+/* AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out */
+static yaffs_Object *yaffs_AllocateEmptyObject(yaffs_Device * dev)
+{
+       yaffs_Object *tn = NULL;
+
+       /* If there are none left make more */
+       if (!dev->freeObjects) {
+               yaffs_CreateFreeObjects(dev, YAFFS_ALLOCATION_NOBJECTS);
+       }
+
+       if (dev->freeObjects) {
+               tn = dev->freeObjects;
+               dev->freeObjects =
+                   (yaffs_Object *) (dev->freeObjects->siblings.next);
+               dev->nFreeObjects--;
+
+               /* Now sweeten it up... */
+
+               memset(tn, 0, sizeof(yaffs_Object));
+               tn->myDev = dev;
+               tn->chunkId = -1;
+               tn->variantType = YAFFS_OBJECT_TYPE_UNKNOWN;
+               INIT_LIST_HEAD(&(tn->hardLinks));
+               INIT_LIST_HEAD(&(tn->hashLink));
+               INIT_LIST_HEAD(&tn->siblings);
+
+               /* Add it to the lost and found directory.
+                * NB Can't put root or lostNFound in lostNFound so
+                * check if lostNFound exists first
+                */
+               if (dev->lostNFoundDir) {
+                       yaffs_AddObjectToDirectory(dev->lostNFoundDir, tn);
+               }
+       }
+
+       return tn;
+}
+
+static yaffs_Object *yaffs_CreateFakeDirectory(yaffs_Device * dev, int number,
+                                              __u32 mode)
+{
+
+       yaffs_Object *obj =
+           yaffs_CreateNewObject(dev, number, YAFFS_OBJECT_TYPE_DIRECTORY);
+       if (obj) {
+               obj->fake = 1;          /* it is fake so it has no NAND presence... */
+               obj->renameAllowed = 0; /* ... and we're not allowed to rename it... */
+               obj->unlinkAllowed = 0; /* ... or unlink it */
+               obj->deleted = 0;
+               obj->unlinked = 0;
+               obj->yst_mode = mode;
+               obj->myDev = dev;
+               obj->chunkId = 0;       /* Not a valid chunk. */
+       }
+
+       return obj;
+
+}
+
+static void yaffs_UnhashObject(yaffs_Object * tn)
+{
+       int bucket;
+       yaffs_Device *dev = tn->myDev;
+
+       /* If it is still linked into the bucket list, free from the list */
+       if (!list_empty(&tn->hashLink)) {
+               list_del_init(&tn->hashLink);
+               bucket = yaffs_HashFunction(tn->objectId);
+               dev->objectBucket[bucket].count--;
+       }
+
+}
+
+/*  FreeObject frees up a Object and puts it back on the free list */
+static void yaffs_FreeObject(yaffs_Object * tn)
+{
+
+       yaffs_Device *dev = tn->myDev;
+
+#ifdef  __KERNEL__
+       if (tn->myInode) {
+               /* We're still hooked up to a cached inode.
+                * Don't delete now, but mark for later deletion
+                */
+               tn->deferedFree = 1;
+               return;
+       }
+#endif
+
+       yaffs_UnhashObject(tn);
+
+       /* Link into the free list. */
+       tn->siblings.next = (struct list_head *)(dev->freeObjects);
+       dev->freeObjects = tn;
+       dev->nFreeObjects++;
+}
+
+#ifdef __KERNEL__
+
+void yaffs_HandleDeferedFree(yaffs_Object * obj)
+{
+       if (obj->deferedFree) {
+               yaffs_FreeObject(obj);
+       }
+}
+
+#endif
+
+static void yaffs_DeinitialiseObjects(yaffs_Device * dev)
+{
+       /* Free the list of allocated Objects */
+
+       yaffs_ObjectList *tmp;
+
+       while (dev->allocatedObjectList) {
+               tmp = dev->allocatedObjectList->next;
+               YFREE(dev->allocatedObjectList->objects);
+               YFREE(dev->allocatedObjectList);
+
+               dev->allocatedObjectList = tmp;
+       }
+
+       dev->freeObjects = NULL;
+       dev->nFreeObjects = 0;
+}
+
+static void yaffs_InitialiseObjects(yaffs_Device * dev)
+{
+       int i;
+
+       dev->allocatedObjectList = NULL;
+       dev->freeObjects = NULL;
+       dev->nFreeObjects = 0;
+
+       for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
+               INIT_LIST_HEAD(&dev->objectBucket[i].list);
+               dev->objectBucket[i].count = 0;
+       }
+
+}
+
+static int yaffs_FindNiceObjectBucket(yaffs_Device * dev)
+{
+       static int x = 0;
+       int i;
+       int l = 999;
+       int lowest = 999999;
+
+       /* First let's see if we can find one that's empty. */
+
+       for (i = 0; i < 10 && lowest > 0; i++) {
+               x++;
+               x %= YAFFS_NOBJECT_BUCKETS;
+               if (dev->objectBucket[x].count < lowest) {
+                       lowest = dev->objectBucket[x].count;
+                       l = x;
+               }
+
+       }
+
+       /* If we didn't find an empty list, then try
+        * looking a bit further for a short one
+        */
+
+       for (i = 0; i < 10 && lowest > 3; i++) {
+               x++;
+               x %= YAFFS_NOBJECT_BUCKETS;
+               if (dev->objectBucket[x].count < lowest) {
+                       lowest = dev->objectBucket[x].count;
+                       l = x;
+               }
+
+       }
+
+       return l;
+}
+
+static int yaffs_CreateNewObjectNumber(yaffs_Device * dev)
+{
+       int bucket = yaffs_FindNiceObjectBucket(dev);
+
+       /* Now find an object value that has not already been taken
+        * by scanning the list.
+        */
+
+       int found = 0;
+       struct list_head *i;
+
+       __u32 n = (__u32) bucket;
+
+       /* yaffs_CheckObjectHashSanity();  */
+
+       while (!found) {
+               found = 1;
+               n += YAFFS_NOBJECT_BUCKETS;
+               if (1 || dev->objectBucket[bucket].count > 0) {
+                       list_for_each(i, &dev->objectBucket[bucket].list) {
+                               /* If there is already one in the list */
+                               if (i
+                                   && list_entry(i, yaffs_Object,
+                                                 hashLink)->objectId == n) {
+                                       found = 0;
+                               }
+                       }
+               }
+       }
+
+
+       return n;
+}
+
+static void yaffs_HashObject(yaffs_Object * in)
+{
+       int bucket = yaffs_HashFunction(in->objectId);
+       yaffs_Device *dev = in->myDev;
+
+       list_add(&in->hashLink, &dev->objectBucket[bucket].list);
+       dev->objectBucket[bucket].count++;
+
+}
+
+yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device * dev, __u32 number)
+{
+       int bucket = yaffs_HashFunction(number);
+       struct list_head *i;
+       yaffs_Object *in;
+
+       list_for_each(i, &dev->objectBucket[bucket].list) {
+               /* Look if it is in the list */
+               if (i) {
+                       in = list_entry(i, yaffs_Object, hashLink);
+                       if (in->objectId == number) {
+#ifdef __KERNEL__
+                               /* Don't tell the VFS about this one if it is defered free */
+                               if (in->deferedFree)
+                                       return NULL;
+#endif
+
+                               return in;
+                       }
+               }
+       }
+
+       return NULL;
+}
+
+yaffs_Object *yaffs_CreateNewObject(yaffs_Device * dev, int number,
+                                   yaffs_ObjectType type)
+{
+
+       yaffs_Object *theObject;
+       yaffs_Tnode *tn;
+
+       if (number < 0) {
+               number = yaffs_CreateNewObjectNumber(dev);
+       }
+
+       theObject = yaffs_AllocateEmptyObject(dev);
+       if(!theObject)
+               return NULL;
+               
+       if(type == YAFFS_OBJECT_TYPE_FILE){
+               tn = yaffs_GetTnode(dev);
+               if(!tn){
+                       yaffs_FreeObject(theObject);
+                       return NULL;
+               }
+       }
+               
+       
+
+       if (theObject) {
+               theObject->fake = 0;
+               theObject->renameAllowed = 1;
+               theObject->unlinkAllowed = 1;
+               theObject->objectId = number;
+               yaffs_HashObject(theObject);
+               theObject->variantType = type;
+#ifdef CONFIG_YAFFS_WINCE
+               yfsd_WinFileTimeNow(theObject->win_atime);
+               theObject->win_ctime[0] = theObject->win_mtime[0] =
+                   theObject->win_atime[0];
+               theObject->win_ctime[1] = theObject->win_mtime[1] =
+                   theObject->win_atime[1];
+
+#else
+
+               theObject->yst_atime = theObject->yst_mtime =
+                   theObject->yst_ctime = Y_CURRENT_TIME;
+#endif
+               switch (type) {
+               case YAFFS_OBJECT_TYPE_FILE:
+                       theObject->variant.fileVariant.fileSize = 0;
+                       theObject->variant.fileVariant.scannedFileSize = 0;
+                       theObject->variant.fileVariant.shrinkSize = 0xFFFFFFFF; /* max __u32 */
+                       theObject->variant.fileVariant.topLevel = 0;
+                       theObject->variant.fileVariant.top = tn;
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       INIT_LIST_HEAD(&theObject->variant.directoryVariant.
+                                      children);
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+                       /* No action required */
+                       break;
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+                       /* todo this should not happen */
+                       break;
+               }
+       }
+
+       return theObject;
+}
+
+static yaffs_Object *yaffs_FindOrCreateObjectByNumber(yaffs_Device * dev,
+                                                     int number,
+                                                     yaffs_ObjectType type)
+{
+       yaffs_Object *theObject = NULL;
+
+       if (number > 0) {
+               theObject = yaffs_FindObjectByNumber(dev, number);
+       }
+
+       if (!theObject) {
+               theObject = yaffs_CreateNewObject(dev, number, type);
+       }
+
+       return theObject;
+
+}
+                       
+
+static YCHAR *yaffs_CloneString(const YCHAR * str)
+{
+       YCHAR *newStr = NULL;
+
+       if (str && *str) {
+               newStr = YMALLOC((yaffs_strlen(str) + 1) * sizeof(YCHAR));
+               if(newStr)
+                       yaffs_strcpy(newStr, str);
+       }
+
+       return newStr;
+
+}
+
+/*
+ * Mknod (create) a new object.
+ * equivalentObject only has meaning for a hard link;
+ * aliasString only has meaning for a sumlink.
+ * rdev only has meaning for devices (a subset of special objects)
+ */
+ 
+static yaffs_Object *yaffs_MknodObject(yaffs_ObjectType type,
+                                      yaffs_Object * parent,
+                                      const YCHAR * name,
+                                      __u32 mode,
+                                      __u32 uid,
+                                      __u32 gid,
+                                      yaffs_Object * equivalentObject,
+                                      const YCHAR * aliasString, __u32 rdev)
+{
+       yaffs_Object *in;
+       YCHAR *str;
+
+       yaffs_Device *dev = parent->myDev;
+
+       /* Check if the entry exists. If it does then fail the call since we don't want a dup.*/
+       if (yaffs_FindObjectByName(parent, name)) {
+               return NULL;
+       }
+
+       in = yaffs_CreateNewObject(dev, -1, type);
+       
+       if(type == YAFFS_OBJECT_TYPE_SYMLINK){
+               str = yaffs_CloneString(aliasString);
+               if(!str){
+                       yaffs_FreeObject(in);
+                       return NULL;
+               }
+       }
+       
+       
+
+       if (in) {
+               in->chunkId = -1;
+               in->valid = 1;
+               in->variantType = type;
+
+               in->yst_mode = mode;
+
+#ifdef CONFIG_YAFFS_WINCE
+               yfsd_WinFileTimeNow(in->win_atime);
+               in->win_ctime[0] = in->win_mtime[0] = in->win_atime[0];
+               in->win_ctime[1] = in->win_mtime[1] = in->win_atime[1];
+
+#else
+               in->yst_atime = in->yst_mtime = in->yst_ctime = Y_CURRENT_TIME;
+
+               in->yst_rdev = rdev;
+               in->yst_uid = uid;
+               in->yst_gid = gid;
+#endif
+               in->nDataChunks = 0;
+
+               yaffs_SetObjectName(in, name);
+               in->dirty = 1;
+
+               yaffs_AddObjectToDirectory(parent, in);
+
+               in->myDev = parent->myDev;
+
+               switch (type) {
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       in->variant.symLinkVariant.alias = str;
+                       break;
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+                       in->variant.hardLinkVariant.equivalentObject =
+                           equivalentObject;
+                       in->variant.hardLinkVariant.equivalentObjectId =
+                           equivalentObject->objectId;
+                       list_add(&in->hardLinks, &equivalentObject->hardLinks);
+                       break;
+               case YAFFS_OBJECT_TYPE_FILE:    
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+                       /* do nothing */
+                       break;
+               }
+
+               if (yaffs_UpdateObjectHeader(in, name, 0, 0, 0) < 0) {
+                       /* Could not create the object header, fail the creation */
+                       yaffs_DestroyObject(in);
+                       in = NULL;
+               }
+
+       }
+
+       return in;
+}
+
+yaffs_Object *yaffs_MknodFile(yaffs_Object * parent, const YCHAR * name,
+                             __u32 mode, __u32 uid, __u32 gid)
+{
+       return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE, parent, name, mode,
+                                uid, gid, NULL, NULL, 0);
+}
+
+yaffs_Object *yaffs_MknodDirectory(yaffs_Object * parent, const YCHAR * name,
+                                  __u32 mode, __u32 uid, __u32 gid)
+{
+       return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY, parent, name,
+                                mode, uid, gid, NULL, NULL, 0);
+}
+
+yaffs_Object *yaffs_MknodSpecial(yaffs_Object * parent, const YCHAR * name,
+                                __u32 mode, __u32 uid, __u32 gid, __u32 rdev)
+{
+       return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SPECIAL, parent, name, mode,
+                                uid, gid, NULL, NULL, rdev);
+}
+
+yaffs_Object *yaffs_MknodSymLink(yaffs_Object * parent, const YCHAR * name,
+                                __u32 mode, __u32 uid, __u32 gid,
+                                const YCHAR * alias)
+{
+       return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK, parent, name, mode,
+                                uid, gid, NULL, alias, 0);
+}
+
+/* yaffs_Link returns the object id of the equivalent object.*/
+yaffs_Object *yaffs_Link(yaffs_Object * parent, const YCHAR * name,
+                        yaffs_Object * equivalentObject)
+{
+       /* Get the real object in case we were fed a hard link as an equivalent object */
+       equivalentObject = yaffs_GetEquivalentObject(equivalentObject);
+
+       if (yaffs_MknodObject
+           (YAFFS_OBJECT_TYPE_HARDLINK, parent, name, 0, 0, 0,
+            equivalentObject, NULL, 0)) {
+               return equivalentObject;
+       } else {
+               return NULL;
+       }
+
+}
+
+static int yaffs_ChangeObjectName(yaffs_Object * obj, yaffs_Object * newDir,
+                                 const YCHAR * newName, int force, int shadows)
+{
+       int unlinkOp;
+       int deleteOp;
+
+       yaffs_Object *existingTarget;
+
+       if (newDir == NULL) {
+               newDir = obj->parent;   /* use the old directory */
+       }
+
+       if (newDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR
+                  ("tragendy: yaffs_ChangeObjectName: newDir is not a directory"
+                   TENDSTR)));
+               YBUG();
+       }
+       
+       /* TODO: Do we need this different handling for YAFFS2 and YAFFS1?? */
+       if (obj->myDev->isYaffs2) {
+               unlinkOp = (newDir == obj->myDev->unlinkedDir);
+       } else {
+               unlinkOp = (newDir == obj->myDev->unlinkedDir
+                           && obj->variantType == YAFFS_OBJECT_TYPE_FILE);
+       }
+
+       deleteOp = (newDir == obj->myDev->deletedDir);
+
+       existingTarget = yaffs_FindObjectByName(newDir, newName);
+
+       /* If the object is a file going into the unlinked directory, 
+        *   then it is OK to just stuff it in since duplicate names are allowed.
+        *   else only proceed if the new name does not exist and if we're putting 
+        *   it into a directory.
+        */
+       if ((unlinkOp ||
+            deleteOp ||
+            force ||
+            (shadows > 0) ||
+            !existingTarget) &&
+           newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY) {
+               yaffs_SetObjectName(obj, newName);
+               obj->dirty = 1;
+
+               yaffs_AddObjectToDirectory(newDir, obj);
+
+               if (unlinkOp)
+                       obj->unlinked = 1;
+
+               /* If it is a deletion then we mark it as a shrink for gc purposes. */
+               if (yaffs_UpdateObjectHeader(obj, newName, 0, deleteOp, shadows)>= 0)
+                       return YAFFS_OK;
+       }
+
+       return YAFFS_FAIL;
+}
+
+int yaffs_RenameObject(yaffs_Object * oldDir, const YCHAR * oldName,
+                      yaffs_Object * newDir, const YCHAR * newName)
+{
+       yaffs_Object *obj;
+       yaffs_Object *existingTarget;
+       int force = 0;
+
+#ifdef CONFIG_YAFFS_CASE_INSENSITIVE
+       /* Special case for case insemsitive systems (eg. WinCE).
+        * While look-up is case insensitive, the name isn't.
+        * Therefore we might want to change x.txt to X.txt
+       */
+       if (oldDir == newDir && yaffs_strcmp(oldName, newName) == 0) {
+               force = 1;
+       }
+#endif
+
+       obj = yaffs_FindObjectByName(oldDir, oldName);
+       /* Check new name to long. */
+       if (obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK &&
+           yaffs_strlen(newName) > YAFFS_MAX_ALIAS_LENGTH)
+         /* ENAMETOOLONG */
+         return YAFFS_FAIL;
+       else if (obj->variantType != YAFFS_OBJECT_TYPE_SYMLINK &&
+                yaffs_strlen(newName) > YAFFS_MAX_NAME_LENGTH)
+         /* ENAMETOOLONG */
+         return YAFFS_FAIL;
+
+       if (obj && obj->renameAllowed) {
+
+               /* Now do the handling for an existing target, if there is one */
+
+               existingTarget = yaffs_FindObjectByName(newDir, newName);
+               if (existingTarget &&
+                   existingTarget->variantType == YAFFS_OBJECT_TYPE_DIRECTORY &&
+                   !list_empty(&existingTarget->variant.directoryVariant.children)) {
+                       /* There is a target that is a non-empty directory, so we fail */
+                       return YAFFS_FAIL;      /* EEXIST or ENOTEMPTY */
+               } else if (existingTarget && existingTarget != obj) {
+                       /* Nuke the target first, using shadowing, 
+                        * but only if it isn't the same object
+                        */
+                       yaffs_ChangeObjectName(obj, newDir, newName, force,
+                                              existingTarget->objectId);
+                       yaffs_UnlinkObject(existingTarget);
+               }
+
+               return yaffs_ChangeObjectName(obj, newDir, newName, 1, 0);
+       }
+       return YAFFS_FAIL;
+}
+
+/*------------------------- Block Management and Page Allocation ----------------*/
+
+static int yaffs_InitialiseBlocks(yaffs_Device * dev)
+{
+       int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
+       
+       dev->blockInfo = NULL;
+       dev->chunkBits = NULL;
+       
+       dev->allocationBlock = -1;      /* force it to get a new one */
+
+       /* If the first allocation strategy fails, thry the alternate one */
+       dev->blockInfo = YMALLOC(nBlocks * sizeof(yaffs_BlockInfo));
+       if(!dev->blockInfo){
+               dev->blockInfo = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockInfo));
+               dev->blockInfoAlt = 1;
+       }
+       else
+               dev->blockInfoAlt = 0;
+               
+       if(dev->blockInfo){
+       
+               /* Set up dynamic blockinfo stuff. */
+               dev->chunkBitmapStride = (dev->nChunksPerBlock + 7) / 8; /* round up bytes */
+               dev->chunkBits = YMALLOC(dev->chunkBitmapStride * nBlocks);
+               if(!dev->chunkBits){
+                       dev->chunkBits = YMALLOC_ALT(dev->chunkBitmapStride * nBlocks);
+                       dev->chunkBitsAlt = 1;
+               }
+               else
+                       dev->chunkBitsAlt = 0;
+       }
+       
+       if (dev->blockInfo && dev->chunkBits) {
+               memset(dev->blockInfo, 0, nBlocks * sizeof(yaffs_BlockInfo));
+               memset(dev->chunkBits, 0, dev->chunkBitmapStride * nBlocks);
+               return YAFFS_OK;
+       }
+
+       return YAFFS_FAIL;
+
+}
+
+static void yaffs_DeinitialiseBlocks(yaffs_Device * dev)
+{
+       if(dev->blockInfoAlt && dev->blockInfo)
+               YFREE_ALT(dev->blockInfo);
+       else if(dev->blockInfo)
+               YFREE(dev->blockInfo);
+
+       dev->blockInfoAlt = 0;
+
+       dev->blockInfo = NULL;
+       
+       if(dev->chunkBitsAlt && dev->chunkBits)
+               YFREE_ALT(dev->chunkBits);
+       else if(dev->chunkBits)
+               YFREE(dev->chunkBits);
+       dev->chunkBitsAlt = 0;
+       dev->chunkBits = NULL;
+}
+
+static int yaffs_BlockNotDisqualifiedFromGC(yaffs_Device * dev,
+                                           yaffs_BlockInfo * bi)
+{
+       int i;
+       __u32 seq;
+       yaffs_BlockInfo *b;
+
+       if (!dev->isYaffs2)
+               return 1;       /* disqualification only applies to yaffs2. */
+
+       if (!bi->hasShrinkHeader)
+               return 1;       /* can gc */
+
+       /* Find the oldest dirty sequence number if we don't know it and save it
+        * so we don't have to keep recomputing it.
+        */
+       if (!dev->oldestDirtySequence) {
+               seq = dev->sequenceNumber;
+
+               for (i = dev->internalStartBlock; i <= dev->internalEndBlock;
+                    i++) {
+                       b = yaffs_GetBlockInfo(dev, i);
+                       if (b->blockState == YAFFS_BLOCK_STATE_FULL &&
+                           (b->pagesInUse - b->softDeletions) <
+                           dev->nChunksPerBlock && b->sequenceNumber < seq) {
+                               seq = b->sequenceNumber;
+                       }
+               }
+               dev->oldestDirtySequence = seq;
+       }
+
+       /* Can't do gc of this block if there are any blocks older than this one that have
+        * discarded pages.
+        */
+       return (bi->sequenceNumber <= dev->oldestDirtySequence);
+
+}
+
+/* FindDiretiestBlock is used to select the dirtiest block (or close enough)
+ * for garbage collection.
+ */
+
+static int yaffs_FindBlockForGarbageCollection(yaffs_Device * dev,
+                                              int aggressive)
+{
+
+       int b = dev->currentDirtyChecker;
+
+       int i;
+       int iterations;
+       int dirtiest = -1;
+       int pagesInUse = 0;
+       int prioritised=0;
+       yaffs_BlockInfo *bi;
+       int pendingPrioritisedExist = 0;
+       
+       /* First let's see if we need to grab a prioritised block */
+       if(dev->hasPendingPrioritisedGCs){
+               for(i = dev->internalStartBlock; i < dev->internalEndBlock && !prioritised; i++){
+
+                       bi = yaffs_GetBlockInfo(dev, i);
+                       //yaffs_VerifyBlock(dev,bi,i);
+                       
+                       if(bi->gcPrioritise) {
+                               pendingPrioritisedExist = 1;
+                               if(bi->blockState == YAFFS_BLOCK_STATE_FULL &&
+                                  yaffs_BlockNotDisqualifiedFromGC(dev, bi)){
+                                       pagesInUse = (bi->pagesInUse - bi->softDeletions);
+                                       dirtiest = i;
+                                       prioritised = 1;
+                                       aggressive = 1; /* Fool the non-aggressive skip logiv below */
+                               }
+                       }
+               }
+               
+               if(!pendingPrioritisedExist) /* None found, so we can clear this */
+                       dev->hasPendingPrioritisedGCs = 0;
+       }
+
+       /* If we're doing aggressive GC then we are happy to take a less-dirty block, and
+        * search harder.
+        * else (we're doing a leasurely gc), then we only bother to do this if the
+        * block has only a few pages in use.
+        */
+
+       dev->nonAggressiveSkip--;
+
+       if (!aggressive && (dev->nonAggressiveSkip > 0)) {
+               return -1;
+       }
+
+       if(!prioritised)
+               pagesInUse =
+                       (aggressive) ? dev->nChunksPerBlock : YAFFS_PASSIVE_GC_CHUNKS + 1;
+
+       if (aggressive) {
+               iterations =
+                   dev->internalEndBlock - dev->internalStartBlock + 1;
+       } else {
+               iterations =
+                   dev->internalEndBlock - dev->internalStartBlock + 1;
+               iterations = iterations / 16;
+               if (iterations > 200) {
+                       iterations = 200;
+               }
+       }
+
+       for (i = 0; i <= iterations && pagesInUse > 0 && !prioritised; i++) {
+               b++;
+               if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
+                       b = dev->internalStartBlock;
+               }
+
+               if (b < dev->internalStartBlock || b > dev->internalEndBlock) {
+                       T(YAFFS_TRACE_ERROR,
+                         (TSTR("**>> Block %d is not valid" TENDSTR), b));
+                       YBUG();
+               }
+
+               bi = yaffs_GetBlockInfo(dev, b);
+
+#if 0
+               if (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT) {
+                       dirtiest = b;
+                       pagesInUse = 0;
+               }
+               else 
+#endif
+
+               if (bi->blockState == YAFFS_BLOCK_STATE_FULL &&
+                      (bi->pagesInUse - bi->softDeletions) < pagesInUse &&
+                       yaffs_BlockNotDisqualifiedFromGC(dev, bi)) {
+                       dirtiest = b;
+                       pagesInUse = (bi->pagesInUse - bi->softDeletions);
+               }
+       }
+
+       dev->currentDirtyChecker = b;
+
+       if (dirtiest > 0) {
+               T(YAFFS_TRACE_GC,
+                 (TSTR("GC Selected block %d with %d free, prioritised:%d" TENDSTR), dirtiest,
+                  dev->nChunksPerBlock - pagesInUse,prioritised));
+       }
+
+       dev->oldestDirtySequence = 0;
+
+       if (dirtiest > 0) {
+               dev->nonAggressiveSkip = 4;
+       }
+
+       return dirtiest;
+}
+
+static void yaffs_BlockBecameDirty(yaffs_Device * dev, int blockNo)
+{
+       yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, blockNo);
+
+       int erasedOk = 0;
+
+       /* If the block is still healthy erase it and mark as clean.
+        * If the block has had a data failure, then retire it.
+        */
+        
+       T(YAFFS_TRACE_GC | YAFFS_TRACE_ERASE,
+               (TSTR("yaffs_BlockBecameDirty block %d state %d %s"TENDSTR),
+               blockNo, bi->blockState, (bi->needsRetiring) ? "needs retiring" : ""));
+               
+       bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
+
+       if (!bi->needsRetiring) {
+               yaffs_InvalidateCheckpoint(dev);
+               erasedOk = yaffs_EraseBlockInNAND(dev, blockNo);
+               if (!erasedOk) {
+                       dev->nErasureFailures++;
+                       T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                         (TSTR("**>> Erasure failed %d" TENDSTR), blockNo));
+               }
+       }
+
+       if (erasedOk && 
+           ((yaffs_traceMask & YAFFS_TRACE_ERASE) || !yaffs_SkipVerification(dev))) {
+               int i;
+               for (i = 0; i < dev->nChunksPerBlock; i++) {
+                       if (!yaffs_CheckChunkErased
+                           (dev, blockNo * dev->nChunksPerBlock + i)) {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  (">>Block %d erasure supposedly OK, but chunk %d not erased"
+                                   TENDSTR), blockNo, i));
+                       }
+               }
+       }
+
+       if (erasedOk) {
+               /* Clean it up... */
+               bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
+               dev->nErasedBlocks++;
+               bi->pagesInUse = 0;
+               bi->softDeletions = 0;
+               bi->hasShrinkHeader = 0;
+               bi->skipErasedCheck = 1;  /* This is clean, so no need to check */
+               bi->gcPrioritise = 0;
+               yaffs_ClearChunkBits(dev, blockNo);
+
+               T(YAFFS_TRACE_ERASE,
+                 (TSTR("Erased block %d" TENDSTR), blockNo));
+       } else {
+               dev->nFreeChunks -= dev->nChunksPerBlock;       /* We lost a block of free space */
+
+               yaffs_RetireBlock(dev, blockNo);
+               T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+                 (TSTR("**>> Block %d retired" TENDSTR), blockNo));
+       }
+}
+
+static int yaffs_FindBlockForAllocation(yaffs_Device * dev)
+{
+       int i;
+
+       yaffs_BlockInfo *bi;
+
+       if (dev->nErasedBlocks < 1) {
+               /* Hoosterman we've got a problem.
+                * Can't get space to gc
+                */
+               T(YAFFS_TRACE_ERROR,
+                 (TSTR("yaffs tragedy: no more eraased blocks" TENDSTR)));
+
+               return -1;
+       }
+       
+       /* Find an empty block. */
+
+       for (i = dev->internalStartBlock; i <= dev->internalEndBlock; i++) {
+               dev->allocationBlockFinder++;
+               if (dev->allocationBlockFinder < dev->internalStartBlock
+                   || dev->allocationBlockFinder > dev->internalEndBlock) {
+                       dev->allocationBlockFinder = dev->internalStartBlock;
+               }
+
+               bi = yaffs_GetBlockInfo(dev, dev->allocationBlockFinder);
+
+               if (bi->blockState == YAFFS_BLOCK_STATE_EMPTY) {
+                       bi->blockState = YAFFS_BLOCK_STATE_ALLOCATING;
+                       dev->sequenceNumber++;
+                       bi->sequenceNumber = dev->sequenceNumber;
+                       dev->nErasedBlocks--;
+                       T(YAFFS_TRACE_ALLOCATE,
+                         (TSTR("Allocated block %d, seq  %d, %d left" TENDSTR),
+                          dev->allocationBlockFinder, dev->sequenceNumber,
+                          dev->nErasedBlocks));
+                       return dev->allocationBlockFinder;
+               }
+       }
+
+       T(YAFFS_TRACE_ALWAYS,
+         (TSTR
+          ("yaffs tragedy: no more eraased blocks, but there should have been %d"
+           TENDSTR), dev->nErasedBlocks));
+
+       return -1;
+}
+
+
+// Check if there's space to allocate...
+// Thinks.... do we need top make this ths same as yaffs_GetFreeChunks()?
+static int yaffs_CheckSpaceForAllocation(yaffs_Device * dev)
+{
+       int reservedChunks;
+       int reservedBlocks = dev->nReservedBlocks;
+       int checkpointBlocks;
+       
+       checkpointBlocks =  dev->nCheckpointReservedBlocks - dev->blocksInCheckpoint;
+       if(checkpointBlocks < 0)
+               checkpointBlocks = 0;
+       
+       reservedChunks = ((reservedBlocks + checkpointBlocks) * dev->nChunksPerBlock);
+       
+       return (dev->nFreeChunks > reservedChunks);
+}
+
+static int yaffs_AllocateChunk(yaffs_Device * dev, int useReserve, yaffs_BlockInfo **blockUsedPtr)
+{
+       int retVal;
+       yaffs_BlockInfo *bi;
+
+       if (dev->allocationBlock < 0) {
+               /* Get next block to allocate off */
+               dev->allocationBlock = yaffs_FindBlockForAllocation(dev);
+               dev->allocationPage = 0;
+       }
+
+       if (!useReserve && !yaffs_CheckSpaceForAllocation(dev)) {
+               /* Not enough space to allocate unless we're allowed to use the reserve. */
+               return -1;
+       }
+
+       if (dev->nErasedBlocks < dev->nReservedBlocks
+           && dev->allocationPage == 0) {
+               T(YAFFS_TRACE_ALLOCATE, (TSTR("Allocating reserve" TENDSTR)));
+       }
+
+       /* Next page please.... */
+       if (dev->allocationBlock >= 0) {
+               bi = yaffs_GetBlockInfo(dev, dev->allocationBlock);
+
+               retVal = (dev->allocationBlock * dev->nChunksPerBlock) +
+                   dev->allocationPage;
+               bi->pagesInUse++;
+               yaffs_SetChunkBit(dev, dev->allocationBlock,
+                                 dev->allocationPage);
+
+               dev->allocationPage++;
+
+               dev->nFreeChunks--;
+
+               /* If the block is full set the state to full */
+               if (dev->allocationPage >= dev->nChunksPerBlock) {
+                       bi->blockState = YAFFS_BLOCK_STATE_FULL;
+                       dev->allocationBlock = -1;
+               }
+
+               if(blockUsedPtr)
+                       *blockUsedPtr = bi;
+                       
+               return retVal;
+       }
+       
+       T(YAFFS_TRACE_ERROR,
+         (TSTR("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!" TENDSTR)));
+
+       return -1;
+}
+
+static int yaffs_GetErasedChunks(yaffs_Device * dev)
+{
+       int n;
+
+       n = dev->nErasedBlocks * dev->nChunksPerBlock;
+
+       if (dev->allocationBlock > 0) {
+               n += (dev->nChunksPerBlock - dev->allocationPage);
+       }
+
+       return n;
+
+}
+
+static int yaffs_GarbageCollectBlock(yaffs_Device * dev, int block)
+{
+       int oldChunk;
+       int newChunk;
+       int chunkInBlock;
+       int markNAND;
+       int retVal = YAFFS_OK;
+       int cleanups = 0;
+       int i;
+       int isCheckpointBlock;
+       int matchingChunk;
+
+       int chunksBefore = yaffs_GetErasedChunks(dev);
+       int chunksAfter;
+
+       yaffs_ExtendedTags tags;
+
+       yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, block);
+
+       yaffs_Object *object;
+
+       isCheckpointBlock = (bi->blockState == YAFFS_BLOCK_STATE_CHECKPOINT);
+       
+       bi->blockState = YAFFS_BLOCK_STATE_COLLECTING;
+
+       T(YAFFS_TRACE_TRACING,
+         (TSTR("Collecting block %d, in use %d, shrink %d, " TENDSTR), block,
+          bi->pagesInUse, bi->hasShrinkHeader));
+
+       /*yaffs_VerifyFreeChunks(dev); */
+
+       bi->hasShrinkHeader = 0;        /* clear the flag so that the block can erase */
+
+       /* Take off the number of soft deleted entries because
+        * they're going to get really deleted during GC.
+        */
+       dev->nFreeChunks -= bi->softDeletions;
+
+       dev->isDoingGC = 1;
+
+       if (isCheckpointBlock ||
+           !yaffs_StillSomeChunkBits(dev, block)) {
+               T(YAFFS_TRACE_TRACING,
+                 (TSTR
+                  ("Collecting block %d that has no chunks in use" TENDSTR),
+                  block));
+               yaffs_BlockBecameDirty(dev, block);
+       } else {
+
+               __u8 *buffer = yaffs_GetTempBuffer(dev, __LINE__);
+               
+               yaffs_VerifyBlock(dev,bi,block);
+
+               for (chunkInBlock = 0, oldChunk = block * dev->nChunksPerBlock;
+                    chunkInBlock < dev->nChunksPerBlock
+                    && yaffs_StillSomeChunkBits(dev, block);
+                    chunkInBlock++, oldChunk++) {
+                       if (yaffs_CheckChunkBit(dev, block, chunkInBlock)) {
+
+                               /* This page is in use and might need to be copied off */
+
+                               markNAND = 1;
+
+                               yaffs_InitialiseTags(&tags);
+
+                               yaffs_ReadChunkWithTagsFromNAND(dev, oldChunk,
+                                                               buffer, &tags);
+
+                               object =
+                                   yaffs_FindObjectByNumber(dev,
+                                                            tags.objectId);
+
+                               T(YAFFS_TRACE_GC_DETAIL,
+                                 (TSTR
+                                  ("Collecting page %d, %d %d %d " TENDSTR),
+                                  chunkInBlock, tags.objectId, tags.chunkId,
+                                  tags.byteCount));
+                                  
+                               if(object && !yaffs_SkipVerification(dev)){
+                                       if(tags.chunkId == 0)
+                                               matchingChunk = object->chunkId;
+                                       else if(object->softDeleted)
+                                               matchingChunk = oldChunk; /* Defeat the test */
+                                       else
+                                               matchingChunk = yaffs_FindChunkInFile(object,tags.chunkId,NULL);
+                                       
+                                       if(oldChunk != matchingChunk)
+                                               T(YAFFS_TRACE_ERROR,
+                                                 (TSTR("gc: page in gc mismatch: %d %d %d %d"TENDSTR),
+                                                 oldChunk,matchingChunk,tags.objectId, tags.chunkId));
+                                               
+                               }
+
+                               if (!object) {
+                                       T(YAFFS_TRACE_ERROR,
+                                         (TSTR
+                                          ("page %d in gc has no object: %d %d %d "
+                                           TENDSTR), oldChunk,
+                                           tags.objectId, tags.chunkId, tags.byteCount));
+                               }
+
+                               if (object && object->deleted
+                                   && tags.chunkId != 0) {
+                                       /* Data chunk in a deleted file, throw it away
+                                        * It's a soft deleted data chunk,
+                                        * No need to copy this, just forget about it and 
+                                        * fix up the object.
+                                        */
+
+                                       object->nDataChunks--;
+
+                                       if (object->nDataChunks <= 0) {
+                                               /* remeber to clean up the object */
+                                               dev->gcCleanupList[cleanups] =
+                                                   tags.objectId;
+                                               cleanups++;
+                                       }
+                                       markNAND = 0;
+                               } else if (0
+                                          /* Todo object && object->deleted && object->nDataChunks == 0 */
+                                          ) {
+                                       /* Deleted object header with no data chunks.
+                                        * Can be discarded and the file deleted.
+                                        */
+                                       object->chunkId = 0;
+                                       yaffs_FreeTnode(object->myDev,
+                                                       object->variant.
+                                                       fileVariant.top);
+                                       object->variant.fileVariant.top = NULL;
+                                       yaffs_DoGenericObjectDeletion(object);
+
+                               } else if (object) {
+                                       /* It's either a data chunk in a live file or
+                                        * an ObjectHeader, so we're interested in it.
+                                        * NB Need to keep the ObjectHeaders of deleted files
+                                        * until the whole file has been deleted off
+                                        */
+                                       tags.serialNumber++;
+
+                                       dev->nGCCopies++;
+
+                                       if (tags.chunkId == 0) {
+                                               /* It is an object Id,
+                                                * We need to nuke the shrinkheader flags first
+                                                * We no longer want the shrinkHeader flag since its work is done
+                                                * and if it is left in place it will mess up scanning.
+                                                * Also, clear out any shadowing stuff
+                                                */
+
+                                               yaffs_ObjectHeader *oh;
+                                               oh = (yaffs_ObjectHeader *)buffer;
+                                               oh->isShrink = 0;
+                                               oh->shadowsObject = -1;
+                                               tags.extraShadows = 0;
+                                               tags.extraIsShrinkHeader = 0;
+                                               
+                                               yaffs_VerifyObjectHeader(object,oh,&tags,1);
+                                       }
+
+                                       newChunk =
+                                           yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &tags, 1);
+
+                                       if (newChunk < 0) {
+                                               retVal = YAFFS_FAIL;
+                                       } else {
+
+                                               /* Ok, now fix up the Tnodes etc. */
+
+                                               if (tags.chunkId == 0) {
+                                                       /* It's a header */
+                                                       object->chunkId =  newChunk;
+                                                       object->serial =   tags.serialNumber;
+                                               } else {
+                                                       /* It's a data chunk */
+                                                       yaffs_PutChunkIntoFile
+                                                           (object,
+                                                            tags.chunkId,
+                                                            newChunk, 0);
+                                               }
+                                       }
+                               }
+
+                               yaffs_DeleteChunk(dev, oldChunk, markNAND, __LINE__);
+
+                       }
+               }
+
+               yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
+
+
+               /* Do any required cleanups */
+               for (i = 0; i < cleanups; i++) {
+                       /* Time to delete the file too */
+                       object =
+                           yaffs_FindObjectByNumber(dev,
+                                                    dev->gcCleanupList[i]);
+                       if (object) {
+                               yaffs_FreeTnode(dev,
+                                               object->variant.fileVariant.
+                                               top);
+                               object->variant.fileVariant.top = NULL;
+                               T(YAFFS_TRACE_GC,
+                                 (TSTR
+                                  ("yaffs: About to finally delete object %d"
+                                   TENDSTR), object->objectId));
+                               yaffs_DoGenericObjectDeletion(object);
+                               object->myDev->nDeletedFiles--;
+                       }
+
+               }
+
+       }
+
+       yaffs_VerifyCollectedBlock(dev,bi,block);
+         
+       if (chunksBefore >= (chunksAfter = yaffs_GetErasedChunks(dev))) {
+               T(YAFFS_TRACE_GC,
+                 (TSTR
+                  ("gc did not increase free chunks before %d after %d"
+                   TENDSTR), chunksBefore, chunksAfter));
+       }
+
+       dev->isDoingGC = 0;
+
+       return YAFFS_OK;
+}
+
+/* New garbage collector
+ * If we're very low on erased blocks then we do aggressive garbage collection
+ * otherwise we do "leasurely" garbage collection.
+ * Aggressive gc looks further (whole array) and will accept less dirty blocks.
+ * Passive gc only inspects smaller areas and will only accept more dirty blocks.
+ *
+ * The idea is to help clear out space in a more spread-out manner.
+ * Dunno if it really does anything useful.
+ */
+static int yaffs_CheckGarbageCollection(yaffs_Device * dev)
+{
+       int block;
+       int aggressive;
+       int gcOk = YAFFS_OK;
+       int maxTries = 0;
+       
+       int checkpointBlockAdjust;
+
+       if (dev->isDoingGC) {
+               /* Bail out so we don't get recursive gc */
+               return YAFFS_OK;
+       }
+       
+       /* This loop should pass the first time.
+        * We'll only see looping here if the erase of the collected block fails.
+        */
+
+       do {
+               maxTries++;
+               
+               checkpointBlockAdjust = (dev->nCheckpointReservedBlocks - dev->blocksInCheckpoint);
+               if(checkpointBlockAdjust < 0)
+                       checkpointBlockAdjust = 0;
+
+               if (dev->nErasedBlocks < (dev->nReservedBlocks + checkpointBlockAdjust + 2)) {
+                       /* We need a block soon...*/
+                       aggressive = 1;
+               } else {
+                       /* We're in no hurry */
+                       aggressive = 0;
+               }
+
+               block = yaffs_FindBlockForGarbageCollection(dev, aggressive);
+
+               if (block > 0) {
+                       dev->garbageCollections++;
+                       if (!aggressive) {
+                               dev->passiveGarbageCollections++;
+                       }
+
+                       T(YAFFS_TRACE_GC,
+                         (TSTR
+                          ("yaffs: GC erasedBlocks %d aggressive %d" TENDSTR),
+                          dev->nErasedBlocks, aggressive));
+
+                       gcOk = yaffs_GarbageCollectBlock(dev, block);
+               }
+
+               if (dev->nErasedBlocks < (dev->nReservedBlocks) && block > 0) {
+                       T(YAFFS_TRACE_GC,
+                         (TSTR
+                          ("yaffs: GC !!!no reclaim!!! erasedBlocks %d after try %d block %d"
+                           TENDSTR), dev->nErasedBlocks, maxTries, block));
+               }
+       } while ((dev->nErasedBlocks < dev->nReservedBlocks) && (block > 0)
+                && (maxTries < 2));
+
+       return aggressive ? gcOk : YAFFS_OK;
+}
+
+/*-------------------------  TAGS --------------------------------*/
+
+static int yaffs_TagsMatch(const yaffs_ExtendedTags * tags, int objectId,
+                          int chunkInObject)
+{
+       return (tags->chunkId == chunkInObject &&
+               tags->objectId == objectId && !tags->chunkDeleted) ? 1 : 0;
+
+}
+
+
+/*-------------------- Data file manipulation -----------------*/
+
+static int yaffs_FindChunkInFile(yaffs_Object * in, int chunkInInode,
+                                yaffs_ExtendedTags * tags)
+{
+       /*Get the Tnode, then get the level 0 offset chunk offset */
+       yaffs_Tnode *tn;
+       int theChunk = -1;
+       yaffs_ExtendedTags localTags;
+       int retVal = -1;
+
+       yaffs_Device *dev = in->myDev;
+
+       if (!tags) {
+               /* Passed a NULL, so use our own tags space */
+               tags = &localTags;
+       }
+
+       tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
+
+       if (tn) {
+               theChunk = yaffs_GetChunkGroupBase(dev,tn,chunkInInode);
+
+               retVal =
+                   yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
+                                          chunkInInode);
+       }
+       return retVal;
+}
+
+static int yaffs_FindAndDeleteChunkInFile(yaffs_Object * in, int chunkInInode,
+                                         yaffs_ExtendedTags * tags)
+{
+       /* Get the Tnode, then get the level 0 offset chunk offset */
+       yaffs_Tnode *tn;
+       int theChunk = -1;
+       yaffs_ExtendedTags localTags;
+
+       yaffs_Device *dev = in->myDev;
+       int retVal = -1;
+
+       if (!tags) {
+               /* Passed a NULL, so use our own tags space */
+               tags = &localTags;
+       }
+
+       tn = yaffs_FindLevel0Tnode(dev, &in->variant.fileVariant, chunkInInode);
+
+       if (tn) {
+
+               theChunk = yaffs_GetChunkGroupBase(dev,tn,chunkInInode);
+
+               retVal =
+                   yaffs_FindChunkInGroup(dev, theChunk, tags, in->objectId,
+                                          chunkInInode);
+
+               /* Delete the entry in the filestructure (if found) */
+               if (retVal != -1) {
+                       yaffs_PutLevel0Tnode(dev,tn,chunkInInode,0);
+               }
+       } else {
+               /*T(("No level 0 found for %d\n", chunkInInode)); */
+       }
+
+       if (retVal == -1) {
+               /* T(("Could not find %d to delete\n",chunkInInode)); */
+       }
+       return retVal;
+}
+
+#ifdef YAFFS_PARANOID
+
+static int yaffs_CheckFileSanity(yaffs_Object * in)
+{
+       int chunk;
+       int nChunks;
+       int fSize;
+       int failed = 0;
+       int objId;
+       yaffs_Tnode *tn;
+       yaffs_Tags localTags;
+       yaffs_Tags *tags = &localTags;
+       int theChunk;
+       int chunkDeleted;
+
+       if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
+               /* T(("Object not a file\n")); */
+               return YAFFS_FAIL;
+       }
+
+       objId = in->objectId;
+       fSize = in->variant.fileVariant.fileSize;
+       nChunks =
+           (fSize + in->myDev->nDataBytesPerChunk - 1) / in->myDev->nDataBytesPerChunk;
+
+       for (chunk = 1; chunk <= nChunks; chunk++) {
+               tn = yaffs_FindLevel0Tnode(in->myDev, &in->variant.fileVariant,
+                                          chunk);
+
+               if (tn) {
+
+                       theChunk = yaffs_GetChunkGroupBase(dev,tn,chunk);
+
+                       if (yaffs_CheckChunkBits
+                           (dev, theChunk / dev->nChunksPerBlock,
+                            theChunk % dev->nChunksPerBlock)) {
+
+                               yaffs_ReadChunkTagsFromNAND(in->myDev, theChunk,
+                                                           tags,
+                                                           &chunkDeleted);
+                               if (yaffs_TagsMatch
+                                   (tags, in->objectId, chunk, chunkDeleted)) {
+                                       /* found it; */
+
+                               }
+                       } else {
+
+                               failed = 1;
+                       }
+
+               } else {
+                       /* T(("No level 0 found for %d\n", chunk)); */
+               }
+       }
+
+       return failed ? YAFFS_FAIL : YAFFS_OK;
+}
+
+#endif
+
+static int yaffs_PutChunkIntoFile(yaffs_Object * in, int chunkInInode,
+                                 int chunkInNAND, int inScan)
+{
+       /* NB inScan is zero unless scanning. 
+        * For forward scanning, inScan is > 0; 
+        * for backward scanning inScan is < 0
+        */
+        
+       yaffs_Tnode *tn;
+       yaffs_Device *dev = in->myDev;
+       int existingChunk;
+       yaffs_ExtendedTags existingTags;
+       yaffs_ExtendedTags newTags;
+       unsigned existingSerial, newSerial;
+
+       if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
+               /* Just ignore an attempt at putting a chunk into a non-file during scanning
+                * If it is not during Scanning then something went wrong!
+                */
+               if (!inScan) {
+                       T(YAFFS_TRACE_ERROR,
+                         (TSTR
+                          ("yaffs tragedy:attempt to put data chunk into a non-file"
+                           TENDSTR)));
+                       YBUG();
+               }
+
+               yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
+               return YAFFS_OK;
+       }
+
+       tn = yaffs_AddOrFindLevel0Tnode(dev, 
+                                       &in->variant.fileVariant,
+                                       chunkInInode,
+                                       NULL);
+       if (!tn) {
+               return YAFFS_FAIL;
+       }
+
+       existingChunk = yaffs_GetChunkGroupBase(dev,tn,chunkInInode);
+
+       if (inScan != 0) {
+               /* If we're scanning then we need to test for duplicates
+                * NB This does not need to be efficient since it should only ever 
+                * happen when the power fails during a write, then only one
+                * chunk should ever be affected.
+                *
+                * Correction for YAFFS2: This could happen quite a lot and we need to think about efficiency! TODO
+                * Update: For backward scanning we don't need to re-read tags so this is quite cheap.
+                */
+
+               if (existingChunk != 0) {
+                       /* NB Right now existing chunk will not be real chunkId if the device >= 32MB
+                        *    thus we have to do a FindChunkInFile to get the real chunk id.
+                        *
+                        * We have a duplicate now we need to decide which one to use:
+                        *
+                        * Backwards scanning YAFFS2: The old one is what we use, dump the new one.
+                        * Forward scanning YAFFS2: The new one is what we use, dump the old one.
+                        * YAFFS1: Get both sets of tags and compare serial numbers.
+                        */
+
+                       if (inScan > 0) {
+                               /* Only do this for forward scanning */
+                               yaffs_ReadChunkWithTagsFromNAND(dev,
+                                                               chunkInNAND,
+                                                               NULL, &newTags);
+
+                               /* Do a proper find */
+                               existingChunk =
+                                   yaffs_FindChunkInFile(in, chunkInInode,
+                                                         &existingTags);
+                       }
+
+                       if (existingChunk <= 0) {
+                               /*Hoosterman - how did this happen? */
+
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  ("yaffs tragedy: existing chunk < 0 in scan"
+                                   TENDSTR)));
+
+                       }
+
+                       /* NB The deleted flags should be false, otherwise the chunks will 
+                        * not be loaded during a scan
+                        */
+
+                       newSerial = newTags.serialNumber;
+                       existingSerial = existingTags.serialNumber;
+
+                       if ((inScan > 0) &&
+                           (in->myDev->isYaffs2 ||
+                            existingChunk <= 0 ||
+                            ((existingSerial + 1) & 3) == newSerial)) {
+                               /* Forward scanning.                            
+                                * Use new
+                                * Delete the old one and drop through to update the tnode
+                                */
+                               yaffs_DeleteChunk(dev, existingChunk, 1,
+                                                 __LINE__);
+                       } else {
+                               /* Backward scanning or we want to use the existing one
+                                * Use existing.
+                                * Delete the new one and return early so that the tnode isn't changed
+                                */
+                               yaffs_DeleteChunk(dev, chunkInNAND, 1,
+                                                 __LINE__);
+                               return YAFFS_OK;
+                       }
+               }
+
+       }
+
+       if (existingChunk == 0) {
+               in->nDataChunks++;
+       }
+
+       yaffs_PutLevel0Tnode(dev,tn,chunkInInode,chunkInNAND);
+
+       return YAFFS_OK;
+}
+
+static int yaffs_ReadChunkDataFromObject(yaffs_Object * in, int chunkInInode,
+                                        __u8 * buffer)
+{
+       int chunkInNAND = yaffs_FindChunkInFile(in, chunkInInode, NULL);
+
+       if (chunkInNAND >= 0) {
+               return yaffs_ReadChunkWithTagsFromNAND(in->myDev, chunkInNAND,
+                                                      buffer,NULL);
+       } else {
+               T(YAFFS_TRACE_NANDACCESS,
+                 (TSTR("Chunk %d not found zero instead" TENDSTR),
+                  chunkInNAND));
+               /* get sane (zero) data if you read a hole */
+               memset(buffer, 0, in->myDev->nDataBytesPerChunk);       
+               return 0;
+       }
+
+}
+
+void yaffs_DeleteChunk(yaffs_Device * dev, int chunkId, int markNAND, int lyn)
+{
+       int block;
+       int page;
+       yaffs_ExtendedTags tags;
+       yaffs_BlockInfo *bi;
+
+       if (chunkId <= 0)
+               return;
+               
+
+       dev->nDeletions++;
+       block = chunkId / dev->nChunksPerBlock;
+       page = chunkId % dev->nChunksPerBlock;
+
+
+       if(!yaffs_CheckChunkBit(dev,block,page))
+               T(YAFFS_TRACE_VERIFY,
+                       (TSTR("Deleting invalid chunk %d"TENDSTR),
+                        chunkId));
+
+       bi = yaffs_GetBlockInfo(dev, block);
+
+       T(YAFFS_TRACE_DELETION,
+         (TSTR("line %d delete of chunk %d" TENDSTR), lyn, chunkId));
+
+       if (markNAND &&
+           bi->blockState != YAFFS_BLOCK_STATE_COLLECTING && !dev->isYaffs2) {
+
+               yaffs_InitialiseTags(&tags);
+
+               tags.chunkDeleted = 1;
+
+               yaffs_WriteChunkWithTagsToNAND(dev, chunkId, NULL, &tags);
+               yaffs_HandleUpdateChunk(dev, chunkId, &tags);
+       } else {
+               dev->nUnmarkedDeletions++;
+       }
+
+       /* Pull out of the management area.
+        * If the whole block became dirty, this will kick off an erasure.
+        */
+       if (bi->blockState == YAFFS_BLOCK_STATE_ALLOCATING ||
+           bi->blockState == YAFFS_BLOCK_STATE_FULL ||
+           bi->blockState == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
+           bi->blockState == YAFFS_BLOCK_STATE_COLLECTING) {
+               dev->nFreeChunks++;
+
+               yaffs_ClearChunkBit(dev, block, page);
+
+               bi->pagesInUse--;
+
+               if (bi->pagesInUse == 0 &&
+                   !bi->hasShrinkHeader &&
+                   bi->blockState != YAFFS_BLOCK_STATE_ALLOCATING &&
+                   bi->blockState != YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                       yaffs_BlockBecameDirty(dev, block);
+               }
+
+       } else {
+               /* T(("Bad news deleting chunk %d\n",chunkId)); */
+       }
+
+}
+
+static int yaffs_WriteChunkDataToObject(yaffs_Object * in, int chunkInInode,
+                                       const __u8 * buffer, int nBytes,
+                                       int useReserve)
+{
+       /* Find old chunk Need to do this to get serial number
+        * Write new one and patch into tree.
+        * Invalidate old tags.
+        */
+
+       int prevChunkId;
+       yaffs_ExtendedTags prevTags;
+
+       int newChunkId;
+       yaffs_ExtendedTags newTags;
+
+       yaffs_Device *dev = in->myDev;
+
+       yaffs_CheckGarbageCollection(dev);
+
+       /* Get the previous chunk at this location in the file if it exists */
+       prevChunkId = yaffs_FindChunkInFile(in, chunkInInode, &prevTags);
+
+       /* Set up new tags */
+       yaffs_InitialiseTags(&newTags);
+
+       newTags.chunkId = chunkInInode;
+       newTags.objectId = in->objectId;
+       newTags.serialNumber =
+           (prevChunkId >= 0) ? prevTags.serialNumber + 1 : 1;
+       newTags.byteCount = nBytes;
+
+       newChunkId =
+           yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
+                                             useReserve);
+
+       if (newChunkId >= 0) {
+               yaffs_PutChunkIntoFile(in, chunkInInode, newChunkId, 0);
+
+               if (prevChunkId >= 0) {
+                       yaffs_DeleteChunk(dev, prevChunkId, 1, __LINE__);
+
+               }
+
+               yaffs_CheckFileSanity(in);
+       }
+       return newChunkId;
+
+}
+
+/* UpdateObjectHeader updates the header on NAND for an object.
+ * If name is not NULL, then that new name is used.
+ */
+int yaffs_UpdateObjectHeader(yaffs_Object * in, const YCHAR * name, int force,
+                            int isShrink, int shadows)
+{
+
+       yaffs_BlockInfo *bi;
+
+       yaffs_Device *dev = in->myDev;
+
+       int prevChunkId;
+       int retVal = 0;
+       int result = 0;
+
+       int newChunkId;
+       yaffs_ExtendedTags newTags;
+       yaffs_ExtendedTags oldTags;
+
+       __u8 *buffer = NULL;
+       YCHAR oldName[YAFFS_MAX_NAME_LENGTH + 1];
+
+       yaffs_ObjectHeader *oh = NULL;
+       
+       yaffs_strcpy(oldName,"silly old name");
+
+       if (!in->fake || force) {
+
+               yaffs_CheckGarbageCollection(dev);
+               yaffs_CheckObjectDetailsLoaded(in);
+
+               buffer = yaffs_GetTempBuffer(in->myDev, __LINE__);
+               oh = (yaffs_ObjectHeader *) buffer;
+
+               prevChunkId = in->chunkId;
+
+               if (prevChunkId >= 0) {
+                       result = yaffs_ReadChunkWithTagsFromNAND(dev, prevChunkId,
+                                                       buffer, &oldTags);
+                       
+                       yaffs_VerifyObjectHeader(in,oh,&oldTags,0);
+                                                                               
+                       memcpy(oldName, oh->name, sizeof(oh->name));
+               }
+
+               memset(buffer, 0xFF, dev->nDataBytesPerChunk);
+
+               oh->type = in->variantType;
+               oh->yst_mode = in->yst_mode;
+               oh->shadowsObject = shadows;
+
+#ifdef CONFIG_YAFFS_WINCE
+               oh->win_atime[0] = in->win_atime[0];
+               oh->win_ctime[0] = in->win_ctime[0];
+               oh->win_mtime[0] = in->win_mtime[0];
+               oh->win_atime[1] = in->win_atime[1];
+               oh->win_ctime[1] = in->win_ctime[1];
+               oh->win_mtime[1] = in->win_mtime[1];
+#else
+               oh->yst_uid = in->yst_uid;
+               oh->yst_gid = in->yst_gid;
+               oh->yst_atime = in->yst_atime;
+               oh->yst_mtime = in->yst_mtime;
+               oh->yst_ctime = in->yst_ctime;
+               oh->yst_rdev = in->yst_rdev;
+#endif
+               if (in->parent) {
+                       oh->parentObjectId = in->parent->objectId;
+               } else {
+                       oh->parentObjectId = 0;
+               }
+
+               if (name && *name) {
+                       memset(oh->name, 0, sizeof(oh->name));
+                       yaffs_strncpy(oh->name, name, YAFFS_MAX_NAME_LENGTH);
+               } else if (prevChunkId>=0) {
+                       memcpy(oh->name, oldName, sizeof(oh->name));
+               } else {
+                       memset(oh->name, 0, sizeof(oh->name));
+               }
+
+               oh->isShrink = isShrink;
+
+               switch (in->variantType) {
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+                       /* Should not happen */
+                       break;
+               case YAFFS_OBJECT_TYPE_FILE:
+                       oh->fileSize =
+                           (oh->parentObjectId == YAFFS_OBJECTID_DELETED
+                            || oh->parentObjectId ==
+                            YAFFS_OBJECTID_UNLINKED) ? 0 : in->variant.
+                           fileVariant.fileSize;
+                       break;
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+                       oh->equivalentObjectId =
+                           in->variant.hardLinkVariant.equivalentObjectId;
+                       break;
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+                       /* Do nothing */
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       /* Do nothing */
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       yaffs_strncpy(oh->alias,
+                                     in->variant.symLinkVariant.alias,
+                                     YAFFS_MAX_ALIAS_LENGTH);
+                       oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
+                       break;
+               }
+
+               /* Tags */
+               yaffs_InitialiseTags(&newTags);
+               in->serial++;
+               newTags.chunkId = 0;
+               newTags.objectId = in->objectId;
+               newTags.serialNumber = in->serial;
+
+               /* Add extra info for file header */
+
+               newTags.extraHeaderInfoAvailable = 1;
+               newTags.extraParentObjectId = oh->parentObjectId;
+               newTags.extraFileLength = oh->fileSize;
+               newTags.extraIsShrinkHeader = oh->isShrink;
+               newTags.extraEquivalentObjectId = oh->equivalentObjectId;
+               newTags.extraShadows = (oh->shadowsObject > 0) ? 1 : 0;
+               newTags.extraObjectType = in->variantType;
+
+               yaffs_VerifyObjectHeader(in,oh,&newTags,1);
+
+               /* Create new chunk in NAND */
+               newChunkId =
+                   yaffs_WriteNewChunkWithTagsToNAND(dev, buffer, &newTags,
+                                                     (prevChunkId >= 0) ? 1 : 0);
+
+               if (newChunkId >= 0) {
+
+                       in->chunkId = newChunkId;
+
+                       if (prevChunkId >= 0) {
+                               yaffs_DeleteChunk(dev, prevChunkId, 1,
+                                                 __LINE__);
+                       }
+
+                       if(!yaffs_ObjectHasCachedWriteData(in))
+                               in->dirty = 0;
+
+                       /* If this was a shrink, then mark the block that the chunk lives on */
+                       if (isShrink) {
+                               bi = yaffs_GetBlockInfo(in->myDev,
+                                                       newChunkId /in->myDev-> nChunksPerBlock);
+                               bi->hasShrinkHeader = 1;
+                       }
+
+               }
+
+               retVal = newChunkId;
+
+       }
+
+       if (buffer)
+               yaffs_ReleaseTempBuffer(dev, buffer, __LINE__);
+
+       return retVal;
+}
+
+/*------------------------ Short Operations Cache ----------------------------------------
+ *   In many situations where there is no high level buffering (eg WinCE) a lot of
+ *   reads might be short sequential reads, and a lot of writes may be short 
+ *   sequential writes. eg. scanning/writing a jpeg file.
+ *   In these cases, a short read/write cache can provide a huge perfomance benefit 
+ *   with dumb-as-a-rock code.
+ *   In Linux, the page cache provides read buffering aand the short op cache provides write 
+ *   buffering.
+ *
+ *   There are a limited number (~10) of cache chunks per device so that we don't
+ *   need a very intelligent search.
+ */
+
+static int yaffs_ObjectHasCachedWriteData(yaffs_Object *obj)
+{
+       yaffs_Device *dev = obj->myDev;
+       int i;
+       yaffs_ChunkCache *cache;
+       int nCaches = obj->myDev->nShortOpCaches;
+       
+       for(i = 0; i < nCaches; i++){
+               cache = &dev->srCache[i];
+               if (cache->object == obj &&
+                   cache->dirty)
+                       return 1;
+       }
+       
+       return 0;
+}
+
+
+static void yaffs_FlushFilesChunkCache(yaffs_Object * obj)
+{
+       yaffs_Device *dev = obj->myDev;
+       int lowest = -99;       /* Stop compiler whining. */
+       int i;
+       yaffs_ChunkCache *cache;
+       int chunkWritten = 0;
+       int nCaches = obj->myDev->nShortOpCaches;
+
+       if (nCaches > 0) {
+               do {
+                       cache = NULL;
+
+                       /* Find the dirty cache for this object with the lowest chunk id. */
+                       for (i = 0; i < nCaches; i++) {
+                               if (dev->srCache[i].object == obj &&
+                                   dev->srCache[i].dirty) {
+                                       if (!cache
+                                           || dev->srCache[i].chunkId <
+                                           lowest) {
+                                               cache = &dev->srCache[i];
+                                               lowest = cache->chunkId;
+                                       }
+                               }
+                       }
+
+                       if (cache && !cache->locked) {
+                               /* Write it out and free it up */
+
+                               chunkWritten =
+                                   yaffs_WriteChunkDataToObject(cache->object,
+                                                                cache->chunkId,
+                                                                cache->data,
+                                                                cache->nBytes,
+                                                                1);
+                               cache->dirty = 0;
+                               cache->object = NULL;
+                       }
+
+               } while (cache && chunkWritten > 0);
+
+               if (cache) {
+                       /* Hoosterman, disk full while writing cache out. */
+                       T(YAFFS_TRACE_ERROR,
+                         (TSTR("yaffs tragedy: no space during cache write" TENDSTR)));
+
+               }
+       }
+
+}
+
+/*yaffs_FlushEntireDeviceCache(dev)
+ *
+ *
+ */
+
+void yaffs_FlushEntireDeviceCache(yaffs_Device *dev)
+{
+       yaffs_Object *obj;
+       int nCaches = dev->nShortOpCaches;
+       int i;
+       
+       /* Find a dirty object in the cache and flush it...
+        * until there are no further dirty objects.
+        */
+       do {
+               obj = NULL;
+               for( i = 0; i < nCaches && !obj; i++) {
+                       if (dev->srCache[i].object &&
+                           dev->srCache[i].dirty)
+                               obj = dev->srCache[i].object;
+                           
+               }
+               if(obj)
+                       yaffs_FlushFilesChunkCache(obj);
+                       
+       } while(obj);
+       
+}
+
+
+/* Grab us a cache chunk for use.
+ * First look for an empty one. 
+ * Then look for the least recently used non-dirty one.
+ * Then look for the least recently used dirty one...., flush and look again.
+ */
+static yaffs_ChunkCache *yaffs_GrabChunkCacheWorker(yaffs_Device * dev)
+{
+       int i;
+       int usage;
+       int theOne;
+
+       if (dev->nShortOpCaches > 0) {
+               for (i = 0; i < dev->nShortOpCaches; i++) {
+                       if (!dev->srCache[i].object) 
+                               return &dev->srCache[i];
+               }
+
+               return NULL;
+
+               theOne = -1;
+               usage = 0;      /* just to stop the compiler grizzling */
+
+               for (i = 0; i < dev->nShortOpCaches; i++) {
+                       if (!dev->srCache[i].dirty &&
+                           ((dev->srCache[i].lastUse < usage && theOne >= 0) ||
+                            theOne < 0)) {
+                               usage = dev->srCache[i].lastUse;
+                               theOne = i;
+                       }
+               }
+
+
+               return theOne >= 0 ? &dev->srCache[theOne] : NULL;
+       } else {
+               return NULL;
+       }
+
+}
+
+static yaffs_ChunkCache *yaffs_GrabChunkCache(yaffs_Device * dev)
+{
+       yaffs_ChunkCache *cache;
+       yaffs_Object *theObj;
+       int usage;
+       int i;
+       int pushout;
+
+       if (dev->nShortOpCaches > 0) {
+               /* Try find a non-dirty one... */
+
+               cache = yaffs_GrabChunkCacheWorker(dev);
+
+               if (!cache) {
+                       /* They were all dirty, find the last recently used object and flush
+                        * its cache, then  find again.
+                        * NB what's here is not very accurate, we actually flush the object
+                        * the last recently used page.
+                        */
+
+                       /* With locking we can't assume we can use entry zero */
+
+                       theObj = NULL;
+                       usage = -1;
+                       cache = NULL;
+                       pushout = -1;
+
+                       for (i = 0; i < dev->nShortOpCaches; i++) {
+                               if (dev->srCache[i].object &&
+                                   !dev->srCache[i].locked &&
+                                   (dev->srCache[i].lastUse < usage || !cache))
+                               {
+                                       usage = dev->srCache[i].lastUse;
+                                       theObj = dev->srCache[i].object;
+                                       cache = &dev->srCache[i];
+                                       pushout = i;
+                               }
+                       }
+
+                       if (!cache || cache->dirty) {
+                               /* Flush and try again */
+                               yaffs_FlushFilesChunkCache(theObj);
+                               cache = yaffs_GrabChunkCacheWorker(dev);
+                       }
+
+               }
+               return cache;
+       } else
+               return NULL;
+
+}
+
+/* Find a cached chunk */
+static yaffs_ChunkCache *yaffs_FindChunkCache(const yaffs_Object * obj,
+                                             int chunkId)
+{
+       yaffs_Device *dev = obj->myDev;
+       int i;
+       if (dev->nShortOpCaches > 0) {
+               for (i = 0; i < dev->nShortOpCaches; i++) {
+                       if (dev->srCache[i].object == obj &&
+                           dev->srCache[i].chunkId == chunkId) {
+                               dev->cacheHits++;
+
+                               return &dev->srCache[i];
+                       }
+               }
+       }
+       return NULL;
+}
+
+/* Mark the chunk for the least recently used algorithym */
+static void yaffs_UseChunkCache(yaffs_Device * dev, yaffs_ChunkCache * cache,
+                               int isAWrite)
+{
+
+       if (dev->nShortOpCaches > 0) {
+               if (dev->srLastUse < 0 || dev->srLastUse > 100000000) {
+                       /* Reset the cache usages */
+                       int i;
+                       for (i = 1; i < dev->nShortOpCaches; i++) {
+                               dev->srCache[i].lastUse = 0;
+                       }
+                       dev->srLastUse = 0;
+               }
+
+               dev->srLastUse++;
+
+               cache->lastUse = dev->srLastUse;
+
+               if (isAWrite) {
+                       cache->dirty = 1;
+               }
+       }
+}
+
+/* Invalidate a single cache page.
+ * Do this when a whole page gets written,
+ * ie the short cache for this page is no longer valid.
+ */
+static void yaffs_InvalidateChunkCache(yaffs_Object * object, int chunkId)
+{
+       if (object->myDev->nShortOpCaches > 0) {
+               yaffs_ChunkCache *cache = yaffs_FindChunkCache(object, chunkId);
+
+               if (cache) {
+                       cache->object = NULL;
+               }
+       }
+}
+
+/* Invalidate all the cache pages associated with this object
+ * Do this whenever ther file is deleted or resized.
+ */
+static void yaffs_InvalidateWholeChunkCache(yaffs_Object * in)
+{
+       int i;
+       yaffs_Device *dev = in->myDev;
+
+       if (dev->nShortOpCaches > 0) {
+               /* Invalidate it. */
+               for (i = 0; i < dev->nShortOpCaches; i++) {
+                       if (dev->srCache[i].object == in) {
+                               dev->srCache[i].object = NULL;
+                       }
+               }
+       }
+}
+
+/*--------------------- Checkpointing --------------------*/
+
+
+static int yaffs_WriteCheckpointValidityMarker(yaffs_Device *dev,int head)
+{
+       yaffs_CheckpointValidity cp;
+       
+       memset(&cp,0,sizeof(cp));
+       
+       cp.structType = sizeof(cp);
+       cp.magic = YAFFS_MAGIC;
+       cp.version = YAFFS_CHECKPOINT_VERSION;
+       cp.head = (head) ? 1 : 0;
+       
+       return (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp))?
+               1 : 0;
+}
+
+static int yaffs_ReadCheckpointValidityMarker(yaffs_Device *dev, int head)
+{
+       yaffs_CheckpointValidity cp;
+       int ok;
+       
+       ok = (yaffs_CheckpointRead(dev,&cp,sizeof(cp)) == sizeof(cp));
+       
+       if(ok)
+               ok = (cp.structType == sizeof(cp)) &&
+                    (cp.magic == YAFFS_MAGIC) &&
+                    (cp.version == YAFFS_CHECKPOINT_VERSION) &&
+                    (cp.head == ((head) ? 1 : 0));
+       return ok ? 1 : 0;
+}
+
+static void yaffs_DeviceToCheckpointDevice(yaffs_CheckpointDevice *cp, 
+                                          yaffs_Device *dev)
+{
+       cp->nErasedBlocks = dev->nErasedBlocks;
+       cp->allocationBlock = dev->allocationBlock;
+       cp->allocationPage = dev->allocationPage;
+       cp->nFreeChunks = dev->nFreeChunks;
+       
+       cp->nDeletedFiles = dev->nDeletedFiles;
+       cp->nUnlinkedFiles = dev->nUnlinkedFiles;
+       cp->nBackgroundDeletions = dev->nBackgroundDeletions;
+       cp->sequenceNumber = dev->sequenceNumber;
+       cp->oldestDirtySequence = dev->oldestDirtySequence;
+       
+}
+
+static void yaffs_CheckpointDeviceToDevice(yaffs_Device *dev,
+                                          yaffs_CheckpointDevice *cp)
+{
+       dev->nErasedBlocks = cp->nErasedBlocks;
+       dev->allocationBlock = cp->allocationBlock;
+       dev->allocationPage = cp->allocationPage;
+       dev->nFreeChunks = cp->nFreeChunks;
+       
+       dev->nDeletedFiles = cp->nDeletedFiles;
+       dev->nUnlinkedFiles = cp->nUnlinkedFiles;
+       dev->nBackgroundDeletions = cp->nBackgroundDeletions;
+       dev->sequenceNumber = cp->sequenceNumber;
+       dev->oldestDirtySequence = cp->oldestDirtySequence;
+}
+
+
+static int yaffs_WriteCheckpointDevice(yaffs_Device *dev)
+{
+       yaffs_CheckpointDevice cp;
+       __u32 nBytes;
+       __u32 nBlocks = (dev->internalEndBlock - dev->internalStartBlock + 1);
+
+       int ok;
+               
+       /* Write device runtime values*/
+       yaffs_DeviceToCheckpointDevice(&cp,dev);
+       cp.structType = sizeof(cp);
+       
+       ok = (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp));
+       
+       /* Write block info */
+       if(ok) {
+               nBytes = nBlocks * sizeof(yaffs_BlockInfo);
+               ok = (yaffs_CheckpointWrite(dev,dev->blockInfo,nBytes) == nBytes);
+       }
+               
+       /* Write chunk bits */          
+       if(ok) {
+               nBytes = nBlocks * dev->chunkBitmapStride;
+               ok = (yaffs_CheckpointWrite(dev,dev->chunkBits,nBytes) == nBytes);
+       }
+       return   ok ? 1 : 0;
+
+}
+
+static int yaffs_ReadCheckpointDevice(yaffs_Device *dev)
+{
+       yaffs_CheckpointDevice cp;
+       __u32 nBytes;
+       __u32 nBlocks = (dev->internalEndBlock - dev->internalStartBlock + 1);
+
+       int ok; 
+       
+       ok = (yaffs_CheckpointRead(dev,&cp,sizeof(cp)) == sizeof(cp));
+       if(!ok)
+               return 0;
+               
+       if(cp.structType != sizeof(cp))
+               return 0;
+               
+       
+       yaffs_CheckpointDeviceToDevice(dev,&cp);
+       
+       nBytes = nBlocks * sizeof(yaffs_BlockInfo);
+       
+       ok = (yaffs_CheckpointRead(dev,dev->blockInfo,nBytes) == nBytes);
+       
+       if(!ok)
+               return 0;
+       nBytes = nBlocks * dev->chunkBitmapStride;
+       
+       ok = (yaffs_CheckpointRead(dev,dev->chunkBits,nBytes) == nBytes);
+       
+       return ok ? 1 : 0;
+}
+
+static void yaffs_ObjectToCheckpointObject(yaffs_CheckpointObject *cp,
+                                          yaffs_Object *obj)
+{
+
+       cp->objectId = obj->objectId;
+       cp->parentId = (obj->parent) ? obj->parent->objectId : 0;
+       cp->chunkId = obj->chunkId;
+       cp->variantType = obj->variantType;                     
+       cp->deleted = obj->deleted;
+       cp->softDeleted = obj->softDeleted;
+       cp->unlinked = obj->unlinked;
+       cp->fake = obj->fake;
+       cp->renameAllowed = obj->renameAllowed;
+       cp->unlinkAllowed = obj->unlinkAllowed;
+       cp->serial = obj->serial;
+       cp->nDataChunks = obj->nDataChunks;
+       
+       if(obj->variantType == YAFFS_OBJECT_TYPE_FILE)
+               cp->fileSizeOrEquivalentObjectId = obj->variant.fileVariant.fileSize;
+       else if(obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK)
+               cp->fileSizeOrEquivalentObjectId = obj->variant.hardLinkVariant.equivalentObjectId;
+}
+
+static void yaffs_CheckpointObjectToObject( yaffs_Object *obj,yaffs_CheckpointObject *cp)
+{
+
+       yaffs_Object *parent;
+       
+       obj->objectId = cp->objectId;
+       
+       if(cp->parentId)
+               parent = yaffs_FindOrCreateObjectByNumber(
+                                       obj->myDev,
+                                       cp->parentId,
+                                       YAFFS_OBJECT_TYPE_DIRECTORY);
+       else
+               parent = NULL;
+               
+       if(parent)
+               yaffs_AddObjectToDirectory(parent, obj);
+               
+       obj->chunkId = cp->chunkId;
+       obj->variantType = cp->variantType;                     
+       obj->deleted = cp->deleted;
+       obj->softDeleted = cp->softDeleted;
+       obj->unlinked = cp->unlinked;
+       obj->fake = cp->fake;
+       obj->renameAllowed = cp->renameAllowed;
+       obj->unlinkAllowed = cp->unlinkAllowed;
+       obj->serial = cp->serial;
+       obj->nDataChunks = cp->nDataChunks;
+       
+       if(obj->variantType == YAFFS_OBJECT_TYPE_FILE)
+               obj->variant.fileVariant.fileSize = cp->fileSizeOrEquivalentObjectId;
+       else if(obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK)
+               obj->variant.hardLinkVariant.equivalentObjectId = cp->fileSizeOrEquivalentObjectId;
+               
+       if(obj->objectId >= YAFFS_NOBJECT_BUCKETS)
+               obj->lazyLoaded = 1;
+}
+
+
+
+static int yaffs_CheckpointTnodeWorker(yaffs_Object * in, yaffs_Tnode * tn,
+                                       __u32 level, int chunkOffset)
+{
+       int i;
+       yaffs_Device *dev = in->myDev;
+       int ok = 1;
+       int nTnodeBytes = (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8;
+
+       if (tn) {
+               if (level > 0) {
+
+                       for (i = 0; i < YAFFS_NTNODES_INTERNAL && ok; i++){
+                               if (tn->internal[i]) {
+                                       ok = yaffs_CheckpointTnodeWorker(in,
+                                                       tn->internal[i],
+                                                       level - 1,
+                                                       (chunkOffset<<YAFFS_TNODES_INTERNAL_BITS) + i);
+                               }
+                       }
+               } else if (level == 0) {
+                       __u32 baseOffset = chunkOffset <<  YAFFS_TNODES_LEVEL0_BITS;
+                       /* printf("write tnode at %d\n",baseOffset); */
+                       ok = (yaffs_CheckpointWrite(dev,&baseOffset,sizeof(baseOffset)) == sizeof(baseOffset));
+                       if(ok)
+                               ok = (yaffs_CheckpointWrite(dev,tn,nTnodeBytes) == nTnodeBytes);
+               }
+       }
+
+       return ok;
+
+}
+
+static int yaffs_WriteCheckpointTnodes(yaffs_Object *obj)
+{
+       __u32 endMarker = ~0;
+       int ok = 1;
+       
+       if(obj->variantType == YAFFS_OBJECT_TYPE_FILE){
+               ok = yaffs_CheckpointTnodeWorker(obj,
+                                           obj->variant.fileVariant.top,
+                                           obj->variant.fileVariant.topLevel,
+                                           0);
+               if(ok)
+                       ok = (yaffs_CheckpointWrite(obj->myDev,&endMarker,sizeof(endMarker)) == 
+                               sizeof(endMarker));
+       }
+       
+       return ok ? 1 : 0;
+}
+
+static int yaffs_ReadCheckpointTnodes(yaffs_Object *obj)
+{
+       __u32 baseChunk;
+       int ok = 1;
+       yaffs_Device *dev = obj->myDev;
+       yaffs_FileStructure *fileStructPtr = &obj->variant.fileVariant;
+       yaffs_Tnode *tn;
+       int nread = 0;
+       
+       ok = (yaffs_CheckpointRead(dev,&baseChunk,sizeof(baseChunk)) == sizeof(baseChunk));
+       
+       while(ok && (~baseChunk)){
+               nread++;
+               /* Read level 0 tnode */
+               
+               
+               /* printf("read  tnode at %d\n",baseChunk); */
+               tn = yaffs_GetTnodeRaw(dev);
+               if(tn)
+                       ok = (yaffs_CheckpointRead(dev,tn,(dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8) ==
+                             (dev->tnodeWidth * YAFFS_NTNODES_LEVEL0)/8);
+               else
+                       ok = 0;
+                       
+               if(tn && ok){
+                       ok = yaffs_AddOrFindLevel0Tnode(dev,
+                                                       fileStructPtr,
+                                                       baseChunk,
+                                                       tn) ? 1 : 0;
+                                                       
+               }
+                       
+               if(ok)
+                       ok = (yaffs_CheckpointRead(dev,&baseChunk,sizeof(baseChunk)) == sizeof(baseChunk));
+               
+       }
+
+       T(YAFFS_TRACE_CHECKPOINT,(
+               TSTR("Checkpoint read tnodes %d records, last %d. ok %d" TENDSTR),
+               nread,baseChunk,ok));
+
+       return ok ? 1 : 0;      
+}
+ 
+
+static int yaffs_WriteCheckpointObjects(yaffs_Device *dev)
+{
+       yaffs_Object *obj;
+       yaffs_CheckpointObject cp;
+       int i;
+       int ok = 1;
+       struct list_head *lh;
+
+       
+       /* Iterate through the objects in each hash entry,
+        * dumping them to the checkpointing stream.
+        */
+        
+        for(i = 0; ok &&  i <  YAFFS_NOBJECT_BUCKETS; i++){
+               list_for_each(lh, &dev->objectBucket[i].list) {
+                       if (lh) {
+                               obj = list_entry(lh, yaffs_Object, hashLink);
+                               if (!obj->deferedFree) {
+                                       yaffs_ObjectToCheckpointObject(&cp,obj);
+                                       cp.structType = sizeof(cp);
+
+                                       T(YAFFS_TRACE_CHECKPOINT,(
+                                               TSTR("Checkpoint write object %d parent %d type %d chunk %d obj addr %x" TENDSTR),
+                                               cp.objectId,cp.parentId,cp.variantType,cp.chunkId,(unsigned) obj));
+                                               
+                                       ok = (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp));
+                                       
+                                       if(ok && obj->variantType == YAFFS_OBJECT_TYPE_FILE){
+                                               ok = yaffs_WriteCheckpointTnodes(obj);
+                                       }
+                               }
+                       }
+               }
+        }
+        
+        /* Dump end of list */
+       memset(&cp,0xFF,sizeof(yaffs_CheckpointObject));
+       cp.structType = sizeof(cp);
+       
+       if(ok)
+               ok = (yaffs_CheckpointWrite(dev,&cp,sizeof(cp)) == sizeof(cp));
+               
+       return ok ? 1 : 0;
+}
+
+static int yaffs_ReadCheckpointObjects(yaffs_Device *dev)
+{
+       yaffs_Object *obj;
+       yaffs_CheckpointObject cp;
+       int ok = 1;
+       int done = 0;
+       yaffs_Object *hardList = NULL;
+       
+       while(ok && !done) {
+               ok = (yaffs_CheckpointRead(dev,&cp,sizeof(cp)) == sizeof(cp));
+               if(cp.structType != sizeof(cp)) {
+                       T(YAFFS_TRACE_CHECKPOINT,(TSTR("struct size %d instead of %d ok %d"TENDSTR),
+                               cp.structType,sizeof(cp),ok));
+                       ok = 0;
+               }
+                       
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("Checkpoint read object %d parent %d type %d chunk %d " TENDSTR),
+                       cp.objectId,cp.parentId,cp.variantType,cp.chunkId));
+                       
+               if(ok && cp.objectId == ~0)
+                       done = 1;
+               else if(ok){
+                       obj = yaffs_FindOrCreateObjectByNumber(dev,cp.objectId, cp.variantType);
+                       if(obj) {
+                               yaffs_CheckpointObjectToObject(obj,&cp);
+                               if(obj->variantType == YAFFS_OBJECT_TYPE_FILE) {
+                                       ok = yaffs_ReadCheckpointTnodes(obj);
+                               } else if(obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK) {
+                                       obj->hardLinks.next =
+                                                   (struct list_head *)
+                                                   hardList;
+                                       hardList = obj;
+                               }
+                          
+                       }
+               }
+       }
+       
+       if(ok)
+               yaffs_HardlinkFixup(dev,hardList);
+       
+       return ok ? 1 : 0;
+}
+
+static int yaffs_WriteCheckpointSum(yaffs_Device *dev)
+{
+       __u32 checkpointSum;
+       int ok;
+       
+       yaffs_GetCheckpointSum(dev,&checkpointSum);
+       
+       ok = (yaffs_CheckpointWrite(dev,&checkpointSum,sizeof(checkpointSum)) == sizeof(checkpointSum));
+       
+       if(!ok)
+               return 0;
+       
+       return 1;
+}
+
+static int yaffs_ReadCheckpointSum(yaffs_Device *dev)
+{
+       __u32 checkpointSum0;
+       __u32 checkpointSum1;
+       int ok;
+       
+       yaffs_GetCheckpointSum(dev,&checkpointSum0);
+       
+       ok = (yaffs_CheckpointRead(dev,&checkpointSum1,sizeof(checkpointSum1)) == sizeof(checkpointSum1));
+       
+       if(!ok)
+               return 0;
+               
+       if(checkpointSum0 != checkpointSum1)
+               return 0;
+       
+       return 1;
+}
+
+
+static int yaffs_WriteCheckpointData(yaffs_Device *dev)
+{
+
+       int ok = 1;
+       
+       if(dev->skipCheckpointWrite || !dev->isYaffs2){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("skipping checkpoint write" TENDSTR)));
+               ok = 0;
+       }
+               
+       if(ok)
+               ok = yaffs_CheckpointOpen(dev,1);
+       
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint validity" TENDSTR)));
+               ok = yaffs_WriteCheckpointValidityMarker(dev,1);
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint device" TENDSTR)));
+               ok = yaffs_WriteCheckpointDevice(dev);
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint objects" TENDSTR)));
+               ok = yaffs_WriteCheckpointObjects(dev);
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("write checkpoint validity" TENDSTR)));
+               ok = yaffs_WriteCheckpointValidityMarker(dev,0);
+       }
+       
+       if(ok){
+               ok = yaffs_WriteCheckpointSum(dev);
+       }
+       
+       
+       if(!yaffs_CheckpointClose(dev))
+                ok = 0;
+                
+       if(ok)
+               dev->isCheckpointed = 1;
+        else 
+               dev->isCheckpointed = 0;
+
+       return dev->isCheckpointed;
+}
+
+static int yaffs_ReadCheckpointData(yaffs_Device *dev)
+{
+       int ok = 1;
+       
+       if(dev->skipCheckpointRead || !dev->isYaffs2){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("skipping checkpoint read" TENDSTR)));
+               ok = 0;
+       }
+       
+       if(ok)
+               ok = yaffs_CheckpointOpen(dev,0); /* open for read */
+       
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint validity" TENDSTR)));   
+               ok = yaffs_ReadCheckpointValidityMarker(dev,1);
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint device" TENDSTR)));
+               ok = yaffs_ReadCheckpointDevice(dev);
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint objects" TENDSTR)));    
+               ok = yaffs_ReadCheckpointObjects(dev);
+       }
+       if(ok){
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint validity" TENDSTR)));
+               ok = yaffs_ReadCheckpointValidityMarker(dev,0);
+       }
+       
+       if(ok){
+               ok = yaffs_ReadCheckpointSum(dev);
+               T(YAFFS_TRACE_CHECKPOINT,(TSTR("read checkpoint checksum %d" TENDSTR),ok));
+       }
+
+       if(!yaffs_CheckpointClose(dev))
+               ok = 0;
+
+       if(ok)
+               dev->isCheckpointed = 1;
+        else 
+               dev->isCheckpointed = 0;
+
+       return ok ? 1 : 0;
+
+}
+
+static void yaffs_InvalidateCheckpoint(yaffs_Device *dev)
+{
+       if(dev->isCheckpointed || 
+          dev->blocksInCheckpoint > 0){
+               dev->isCheckpointed = 0;
+               yaffs_CheckpointInvalidateStream(dev);
+               if(dev->superBlock && dev->markSuperBlockDirty)
+                       dev->markSuperBlockDirty(dev->superBlock);
+       }
+}
+
+
+int yaffs_CheckpointSave(yaffs_Device *dev)
+{
+
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("save entry: isCheckpointed %d"TENDSTR),dev->isCheckpointed));
+
+       yaffs_VerifyObjects(dev);
+       yaffs_VerifyBlocks(dev);
+       yaffs_VerifyFreeChunks(dev);
+
+       if(!dev->isCheckpointed) {
+               yaffs_InvalidateCheckpoint(dev);
+               yaffs_WriteCheckpointData(dev);
+       }
+       
+       T(YAFFS_TRACE_ALWAYS,(TSTR("save exit: isCheckpointed %d"TENDSTR),dev->isCheckpointed));
+
+       return dev->isCheckpointed;
+}
+
+int yaffs_CheckpointRestore(yaffs_Device *dev)
+{
+       int retval;
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("restore entry: isCheckpointed %d"TENDSTR),dev->isCheckpointed));
+               
+       retval = yaffs_ReadCheckpointData(dev);
+
+       if(dev->isCheckpointed){
+               yaffs_VerifyObjects(dev);
+               yaffs_VerifyBlocks(dev);
+               yaffs_VerifyFreeChunks(dev);
+       }
+
+       T(YAFFS_TRACE_CHECKPOINT,(TSTR("restore exit: isCheckpointed %d"TENDSTR),dev->isCheckpointed));
+       
+       return retval;
+}
+
+/*--------------------- File read/write ------------------------
+ * Read and write have very similar structures.
+ * In general the read/write has three parts to it
+ * An incomplete chunk to start with (if the read/write is not chunk-aligned)
+ * Some complete chunks
+ * An incomplete chunk to end off with
+ *
+ * Curve-balls: the first chunk might also be the last chunk.
+ */
+
+int yaffs_ReadDataFromFile(yaffs_Object * in, __u8 * buffer, loff_t offset,
+                          int nBytes)
+{
+
+       int chunk;
+       int start;
+       int nToCopy;
+       int n = nBytes;
+       int nDone = 0;
+       yaffs_ChunkCache *cache;
+
+       yaffs_Device *dev;
+
+       dev = in->myDev;
+
+       while (n > 0) {
+               //chunk = offset / dev->nDataBytesPerChunk + 1;
+               //start = offset % dev->nDataBytesPerChunk;
+               yaffs_AddrToChunk(dev,offset,&chunk,&start);
+               chunk++;
+
+               /* OK now check for the curveball where the start and end are in
+                * the same chunk.      
+                */
+               if ((start + n) < dev->nDataBytesPerChunk) {
+                       nToCopy = n;
+               } else {
+                       nToCopy = dev->nDataBytesPerChunk - start;
+               }
+
+               cache = yaffs_FindChunkCache(in, chunk);
+
+               /* If the chunk is already in the cache or it is less than a whole chunk
+                * then use the cache (if there is caching)
+                * else bypass the cache.
+                */
+               if (cache || nToCopy != dev->nDataBytesPerChunk) {
+                       if (dev->nShortOpCaches > 0) {
+
+                               /* If we can't find the data in the cache, then load it up. */
+
+                               if (!cache) {
+                                       cache = yaffs_GrabChunkCache(in->myDev);
+                                       cache->object = in;
+                                       cache->chunkId = chunk;
+                                       cache->dirty = 0;
+                                       cache->locked = 0;
+                                       yaffs_ReadChunkDataFromObject(in, chunk,
+                                                                     cache->
+                                                                     data);
+                                       cache->nBytes = 0;
+                               }
+
+                               yaffs_UseChunkCache(dev, cache, 0);
+
+                               cache->locked = 1;
+
+#ifdef CONFIG_YAFFS_WINCE
+                               yfsd_UnlockYAFFS(TRUE);
+#endif
+                               memcpy(buffer, &cache->data[start], nToCopy);
+
+#ifdef CONFIG_YAFFS_WINCE
+                               yfsd_LockYAFFS(TRUE);
+#endif
+                               cache->locked = 0;
+                       } else {
+                               /* Read into the local buffer then copy..*/
+
+                               __u8 *localBuffer =
+                                   yaffs_GetTempBuffer(dev, __LINE__);
+                               yaffs_ReadChunkDataFromObject(in, chunk,
+                                                             localBuffer);
+#ifdef CONFIG_YAFFS_WINCE
+                               yfsd_UnlockYAFFS(TRUE);
+#endif
+                               memcpy(buffer, &localBuffer[start], nToCopy);
+
+#ifdef CONFIG_YAFFS_WINCE
+                               yfsd_LockYAFFS(TRUE);
+#endif
+                               yaffs_ReleaseTempBuffer(dev, localBuffer,
+                                                       __LINE__);
+                       }
+
+               } else {
+#ifdef CONFIG_YAFFS_WINCE
+                       __u8 *localBuffer = yaffs_GetTempBuffer(dev, __LINE__);
+
+                       /* Under WinCE can't do direct transfer. Need to use a local buffer.
+                        * This is because we otherwise screw up WinCE's memory mapper
+                        */
+                       yaffs_ReadChunkDataFromObject(in, chunk, localBuffer);
+
+#ifdef CONFIG_YAFFS_WINCE
+                       yfsd_UnlockYAFFS(TRUE);
+#endif
+                       memcpy(buffer, localBuffer, dev->nDataBytesPerChunk);
+
+#ifdef CONFIG_YAFFS_WINCE
+                       yfsd_LockYAFFS(TRUE);
+                       yaffs_ReleaseTempBuffer(dev, localBuffer, __LINE__);
+#endif
+
+#else
+                       /* A full chunk. Read directly into the supplied buffer. */
+                       yaffs_ReadChunkDataFromObject(in, chunk, buffer);
+#endif
+               }
+
+               n -= nToCopy;
+               offset += nToCopy;
+               buffer += nToCopy;
+               nDone += nToCopy;
+
+       }
+
+       return nDone;
+}
+
+int yaffs_WriteDataToFile(yaffs_Object * in, const __u8 * buffer, loff_t offset,
+                         int nBytes, int writeThrough)
+{
+
+       int chunk;
+       int start;
+       int nToCopy;
+       int n = nBytes;
+       int nDone = 0;
+       int nToWriteBack;
+       int startOfWrite = offset;
+       int chunkWritten = 0;
+       int nBytesRead;
+
+       yaffs_Device *dev;
+
+       dev = in->myDev;
+
+       while (n > 0 && chunkWritten >= 0) {
+               //chunk = offset / dev->nDataBytesPerChunk + 1;
+               //start = offset % dev->nDataBytesPerChunk;
+               yaffs_AddrToChunk(dev,offset,&chunk,&start);
+               chunk++;
+
+               /* OK now check for the curveball where the start and end are in
+                * the same chunk.
+                */
+
+               if ((start + n) < dev->nDataBytesPerChunk) {
+                       nToCopy = n;
+
+                       /* Now folks, to calculate how many bytes to write back....
+                        * If we're overwriting and not writing to then end of file then
+                        * we need to write back as much as was there before.
+                        */
+
+                       nBytesRead =
+                           in->variant.fileVariant.fileSize -
+                           ((chunk - 1) * dev->nDataBytesPerChunk);
+
+                       if (nBytesRead > dev->nDataBytesPerChunk) {
+                               nBytesRead = dev->nDataBytesPerChunk;
+                       }
+
+                       nToWriteBack =
+                           (nBytesRead >
+                            (start + n)) ? nBytesRead : (start + n);
+
+               } else {
+                       nToCopy = dev->nDataBytesPerChunk - start;
+                       nToWriteBack = dev->nDataBytesPerChunk;
+               }
+
+               if (nToCopy != dev->nDataBytesPerChunk) {
+                       /* An incomplete start or end chunk (or maybe both start and end chunk) */
+                       if (dev->nShortOpCaches > 0) {
+                               yaffs_ChunkCache *cache;
+                               /* If we can't find the data in the cache, then load the cache */
+                               cache = yaffs_FindChunkCache(in, chunk);
+                               
+                               if (!cache
+                                   && yaffs_CheckSpaceForAllocation(in->
+                                                                    myDev)) {
+                                       cache = yaffs_GrabChunkCache(in->myDev);
+                                       cache->object = in;
+                                       cache->chunkId = chunk;
+                                       cache->dirty = 0;
+                                       cache->locked = 0;
+                                       yaffs_ReadChunkDataFromObject(in, chunk,
+                                                                     cache->
+                                                                     data);
+                               }
+                               else if(cache && 
+                                       !cache->dirty &&
+                                       !yaffs_CheckSpaceForAllocation(in->myDev)){
+                                       /* Drop the cache if it was a read cache item and
+                                        * no space check has been made for it.
+                                        */ 
+                                        cache = NULL;
+                               }
+
+                               if (cache) {
+                                       yaffs_UseChunkCache(dev, cache, 1);
+                                       cache->locked = 1;
+#ifdef CONFIG_YAFFS_WINCE
+                                       yfsd_UnlockYAFFS(TRUE);
+#endif
+
+                                       memcpy(&cache->data[start], buffer,
+                                              nToCopy);
+
+#ifdef CONFIG_YAFFS_WINCE
+                                       yfsd_LockYAFFS(TRUE);
+#endif
+                                       cache->locked = 0;
+                                       cache->nBytes = nToWriteBack;
+
+                                       if (writeThrough) {
+                                               chunkWritten =
+                                                   yaffs_WriteChunkDataToObject
+                                                   (cache->object,
+                                                    cache->chunkId,
+                                                    cache->data, cache->nBytes,
+                                                    1);
+                                               cache->dirty = 0;
+                                       }
+
+                               } else {
+                                       chunkWritten = -1;      /* fail the write */
+                               }
+                       } else {
+                               /* An incomplete start or end chunk (or maybe both start and end chunk)
+                                * Read into the local buffer then copy, then copy over and write back.
+                                */
+
+                               __u8 *localBuffer =
+                                   yaffs_GetTempBuffer(dev, __LINE__);
+
+                               yaffs_ReadChunkDataFromObject(in, chunk,
+                                                             localBuffer);
+
+#ifdef CONFIG_YAFFS_WINCE
+                               yfsd_UnlockYAFFS(TRUE);
+#endif
+
+                               memcpy(&localBuffer[start], buffer, nToCopy);
+
+#ifdef CONFIG_YAFFS_WINCE
+                               yfsd_LockYAFFS(TRUE);
+#endif
+                               chunkWritten =
+                                   yaffs_WriteChunkDataToObject(in, chunk,
+                                                                localBuffer,
+                                                                nToWriteBack,
+                                                                0);
+
+                               yaffs_ReleaseTempBuffer(dev, localBuffer,
+                                                       __LINE__);
+
+                       }
+
+               } else {
+
+#ifdef CONFIG_YAFFS_WINCE
+                       /* Under WinCE can't do direct transfer. Need to use a local buffer.
+                        * This is because we otherwise screw up WinCE's memory mapper
+                        */
+                       __u8 *localBuffer = yaffs_GetTempBuffer(dev, __LINE__);
+#ifdef CONFIG_YAFFS_WINCE
+                       yfsd_UnlockYAFFS(TRUE);
+#endif
+                       memcpy(localBuffer, buffer, dev->nDataBytesPerChunk);
+#ifdef CONFIG_YAFFS_WINCE
+                       yfsd_LockYAFFS(TRUE);
+#endif
+                       chunkWritten =
+                           yaffs_WriteChunkDataToObject(in, chunk, localBuffer,
+                                                        dev->nDataBytesPerChunk,
+                                                        0);
+                       yaffs_ReleaseTempBuffer(dev, localBuffer, __LINE__);
+#else
+                       /* A full chunk. Write directly from the supplied buffer. */
+                       chunkWritten =
+                           yaffs_WriteChunkDataToObject(in, chunk, buffer,
+                                                        dev->nDataBytesPerChunk,
+                                                        0);
+#endif
+                       /* Since we've overwritten the cached data, we better invalidate it. */
+                       yaffs_InvalidateChunkCache(in, chunk);
+               }
+
+               if (chunkWritten >= 0) {
+                       n -= nToCopy;
+                       offset += nToCopy;
+                       buffer += nToCopy;
+                       nDone += nToCopy;
+               }
+
+       }
+
+       /* Update file object */
+
+       if ((startOfWrite + nDone) > in->variant.fileVariant.fileSize) {
+               in->variant.fileVariant.fileSize = (startOfWrite + nDone);
+       }
+
+       in->dirty = 1;
+
+       return nDone;
+}
+
+
+/* ---------------------- File resizing stuff ------------------ */
+
+static void yaffs_PruneResizedChunks(yaffs_Object * in, int newSize)
+{
+
+       yaffs_Device *dev = in->myDev;
+       int oldFileSize = in->variant.fileVariant.fileSize;
+
+       int lastDel = 1 + (oldFileSize - 1) / dev->nDataBytesPerChunk;
+
+       int startDel = 1 + (newSize + dev->nDataBytesPerChunk - 1) /
+           dev->nDataBytesPerChunk;
+       int i;
+       int chunkId;
+
+       /* Delete backwards so that we don't end up with holes if
+        * power is lost part-way through the operation.
+        */
+       for (i = lastDel; i >= startDel; i--) {
+               /* NB this could be optimised somewhat,
+                * eg. could retrieve the tags and write them without
+                * using yaffs_DeleteChunk
+                */
+
+               chunkId = yaffs_FindAndDeleteChunkInFile(in, i, NULL);
+               if (chunkId > 0) {
+                       if (chunkId <
+                           (dev->internalStartBlock * dev->nChunksPerBlock)
+                           || chunkId >=
+                           ((dev->internalEndBlock +
+                             1) * dev->nChunksPerBlock)) {
+                               T(YAFFS_TRACE_ALWAYS,
+                                 (TSTR("Found daft chunkId %d for %d" TENDSTR),
+                                  chunkId, i));
+                       } else {
+                               in->nDataChunks--;
+                               yaffs_DeleteChunk(dev, chunkId, 1, __LINE__);
+                       }
+               }
+       }
+
+}
+
+int yaffs_ResizeFile(yaffs_Object * in, loff_t newSize)
+{
+
+       int oldFileSize = in->variant.fileVariant.fileSize;
+       int newSizeOfPartialChunk;
+       int newFullChunks;
+       
+       yaffs_Device *dev = in->myDev;
+
+       yaffs_AddrToChunk(dev, newSize, &newFullChunks, &newSizeOfPartialChunk);
+
+       yaffs_FlushFilesChunkCache(in);
+       yaffs_InvalidateWholeChunkCache(in);
+
+       yaffs_CheckGarbageCollection(dev);
+
+       if (in->variantType != YAFFS_OBJECT_TYPE_FILE) {
+               return yaffs_GetFileSize(in);
+       }
+
+       if (newSize == oldFileSize) {
+               return oldFileSize;
+       }
+
+       if (newSize < oldFileSize) {
+
+               yaffs_PruneResizedChunks(in, newSize);
+
+               if (newSizeOfPartialChunk != 0) {
+                       int lastChunk = 1 + newFullChunks;
+                       
+                       __u8 *localBuffer = yaffs_GetTempBuffer(dev, __LINE__);
+
+                       /* Got to read and rewrite the last chunk with its new size and zero pad */
+                       yaffs_ReadChunkDataFromObject(in, lastChunk,
+                                                     localBuffer);
+
+                       memset(localBuffer + newSizeOfPartialChunk, 0,
+                              dev->nDataBytesPerChunk - newSizeOfPartialChunk);
+
+                       yaffs_WriteChunkDataToObject(in, lastChunk, localBuffer,
+                                                    newSizeOfPartialChunk, 1);
+
+                       yaffs_ReleaseTempBuffer(dev, localBuffer, __LINE__);
+               }
+
+               in->variant.fileVariant.fileSize = newSize;
+
+               yaffs_PruneFileStructure(dev, &in->variant.fileVariant);
+       } else {
+               /* newsSize > oldFileSize */
+               in->variant.fileVariant.fileSize = newSize;
+       }
+
+               
+       
+       /* Write a new object header.
+        * show we've shrunk the file, if need be
+        * Do this only if the file is not in the deleted directories.
+        */
+       if (in->parent->objectId != YAFFS_OBJECTID_UNLINKED &&
+           in->parent->objectId != YAFFS_OBJECTID_DELETED) {
+               yaffs_UpdateObjectHeader(in, NULL, 0,
+                                        (newSize < oldFileSize) ? 1 : 0, 0);
+       }
+
+       return newSize;
+}
+
+loff_t yaffs_GetFileSize(yaffs_Object * obj)
+{
+       obj = yaffs_GetEquivalentObject(obj);
+
+       switch (obj->variantType) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               return obj->variant.fileVariant.fileSize;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               return yaffs_strlen(obj->variant.symLinkVariant.alias);
+       default:
+               return 0;
+       }
+}
+
+
+
+int yaffs_FlushFile(yaffs_Object * in, int updateTime)
+{
+       int retVal;
+       if (in->dirty) {
+               yaffs_FlushFilesChunkCache(in);
+               if (updateTime) {
+#ifdef CONFIG_YAFFS_WINCE
+                       yfsd_WinFileTimeNow(in->win_mtime);
+#else
+
+                       in->yst_mtime = Y_CURRENT_TIME;
+
+#endif
+               }
+
+               retVal =
+                   (yaffs_UpdateObjectHeader(in, NULL, 0, 0, 0) >=
+                    0) ? YAFFS_OK : YAFFS_FAIL;
+       } else {
+               retVal = YAFFS_OK;
+       }
+
+       return retVal;
+
+}
+
+static int yaffs_DoGenericObjectDeletion(yaffs_Object * in)
+{
+
+       /* First off, invalidate the file's data in the cache, without flushing. */
+       yaffs_InvalidateWholeChunkCache(in);
+
+       if (in->myDev->isYaffs2 && (in->parent != in->myDev->deletedDir)) {
+               /* Move to the unlinked directory so we have a record that it was deleted. */
+               yaffs_ChangeObjectName(in, in->myDev->deletedDir,"deleted", 0, 0);
+
+       }
+
+       yaffs_RemoveObjectFromDirectory(in);
+       yaffs_DeleteChunk(in->myDev, in->chunkId, 1, __LINE__);
+       in->chunkId = -1;
+
+       yaffs_FreeObject(in);
+       return YAFFS_OK;
+
+}
+
+/* yaffs_DeleteFile deletes the whole file data
+ * and the inode associated with the file.
+ * It does not delete the links associated with the file.
+ */
+static int yaffs_UnlinkFile(yaffs_Object * in)
+{
+
+       int retVal;
+       int immediateDeletion = 0;
+
+       if (1) {
+#ifdef __KERNEL__
+               if (!in->myInode) {
+                       immediateDeletion = 1;
+
+               }
+#else
+               if (in->inUse <= 0) {
+                       immediateDeletion = 1;
+
+               }
+#endif
+               if (immediateDeletion) {
+                       retVal =
+                           yaffs_ChangeObjectName(in, in->myDev->deletedDir,
+                                                  "deleted", 0, 0);
+                       T(YAFFS_TRACE_TRACING,
+                         (TSTR("yaffs: immediate deletion of file %d" TENDSTR),
+                          in->objectId));
+                       in->deleted = 1;
+                       in->myDev->nDeletedFiles++;
+                       if (0 && in->myDev->isYaffs2) {
+                               yaffs_ResizeFile(in, 0);
+                       }
+                       yaffs_SoftDeleteFile(in);
+               } else {
+                       retVal =
+                           yaffs_ChangeObjectName(in, in->myDev->unlinkedDir,
+                                                  "unlinked", 0, 0);
+               }
+
+       }
+       return retVal;
+}
+
+int yaffs_DeleteFile(yaffs_Object * in)
+{
+       int retVal = YAFFS_OK;
+
+       if (in->nDataChunks > 0) {
+               /* Use soft deletion if there is data in the file */
+               if (!in->unlinked) {
+                       retVal = yaffs_UnlinkFile(in);
+               }
+               if (retVal == YAFFS_OK && in->unlinked && !in->deleted) {
+                       in->deleted = 1;
+                       in->myDev->nDeletedFiles++;
+                       yaffs_SoftDeleteFile(in);
+               }
+               return in->deleted ? YAFFS_OK : YAFFS_FAIL;
+       } else {
+               /* The file has no data chunks so we toss it immediately */
+               yaffs_FreeTnode(in->myDev, in->variant.fileVariant.top);
+               in->variant.fileVariant.top = NULL;
+               yaffs_DoGenericObjectDeletion(in);
+
+               return YAFFS_OK;
+       }
+}
+
+static int yaffs_DeleteDirectory(yaffs_Object * in)
+{
+       /* First check that the directory is empty. */
+       if (list_empty(&in->variant.directoryVariant.children)) {
+               return yaffs_DoGenericObjectDeletion(in);
+       }
+
+       return YAFFS_FAIL;
+
+}
+
+static int yaffs_DeleteSymLink(yaffs_Object * in)
+{
+       YFREE(in->variant.symLinkVariant.alias);
+
+       return yaffs_DoGenericObjectDeletion(in);
+}
+
+static int yaffs_DeleteHardLink(yaffs_Object * in)
+{
+       /* remove this hardlink from the list assocaited with the equivalent
+        * object
+        */
+       list_del(&in->hardLinks);
+       return yaffs_DoGenericObjectDeletion(in);
+}
+
+static void yaffs_DestroyObject(yaffs_Object * obj)
+{
+       switch (obj->variantType) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               yaffs_DeleteFile(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_DIRECTORY:
+               yaffs_DeleteDirectory(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               yaffs_DeleteSymLink(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_HARDLINK:
+               yaffs_DeleteHardLink(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_SPECIAL:
+               yaffs_DoGenericObjectDeletion(obj);
+               break;
+       case YAFFS_OBJECT_TYPE_UNKNOWN:
+               break;          /* should not happen. */
+       }
+}
+
+static int yaffs_UnlinkWorker(yaffs_Object * obj)
+{
+
+       if (obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK) {
+               return yaffs_DeleteHardLink(obj);
+       } else if (!list_empty(&obj->hardLinks)) {
+               /* Curve ball: We're unlinking an object that has a hardlink.
+                *
+                * This problem arises because we are not strictly following
+                * The Linux link/inode model.
+                *
+                * We can't really delete the object.
+                * Instead, we do the following:
+                * - Select a hardlink.
+                * - Unhook it from the hard links
+                * - Unhook it from its parent directory (so that the rename can work)
+                * - Rename the object to the hardlink's name.
+                * - Delete the hardlink
+                */
+
+               yaffs_Object *hl;
+               int retVal;
+               YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+               hl = list_entry(obj->hardLinks.next, yaffs_Object, hardLinks);
+
+               list_del_init(&hl->hardLinks);
+               list_del_init(&hl->siblings);
+
+               yaffs_GetObjectName(hl, name, YAFFS_MAX_NAME_LENGTH + 1);
+
+               retVal = yaffs_ChangeObjectName(obj, hl->parent, name, 0, 0);
+
+               if (retVal == YAFFS_OK) {
+                       retVal = yaffs_DoGenericObjectDeletion(hl);
+               }
+               return retVal;
+
+       } else {
+               switch (obj->variantType) {
+               case YAFFS_OBJECT_TYPE_FILE:
+                       return yaffs_UnlinkFile(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_DIRECTORY:
+                       return yaffs_DeleteDirectory(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_SYMLINK:
+                       return yaffs_DeleteSymLink(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_SPECIAL:
+                       return yaffs_DoGenericObjectDeletion(obj);
+                       break;
+               case YAFFS_OBJECT_TYPE_HARDLINK:
+               case YAFFS_OBJECT_TYPE_UNKNOWN:
+               default:
+                       return YAFFS_FAIL;
+               }
+       }
+}
+
+
+static int yaffs_UnlinkObject( yaffs_Object *obj)
+{
+
+       if (obj && obj->unlinkAllowed) {
+               return yaffs_UnlinkWorker(obj);
+       }
+
+       return YAFFS_FAIL;
+
+}
+int yaffs_Unlink(yaffs_Object * dir, const YCHAR * name)
+{
+       yaffs_Object *obj;
+
+       obj = yaffs_FindObjectByName(dir, name);
+       return yaffs_UnlinkObject(obj);
+}
+
+/*----------------------- Initialisation Scanning ---------------------- */
+
+static void yaffs_HandleShadowedObject(yaffs_Device * dev, int objId,
+                                      int backwardScanning)
+{
+       yaffs_Object *obj;
+
+       if (!backwardScanning) {
+               /* Handle YAFFS1 forward scanning case
+                * For YAFFS1 we always do the deletion
+                */
+
+       } else {
+               /* Handle YAFFS2 case (backward scanning)
+                * If the shadowed object exists then ignore.
+                */
+               if (yaffs_FindObjectByNumber(dev, objId)) {
+                       return;
+               }
+       }
+
+       /* Let's create it (if it does not exist) assuming it is a file so that it can do shrinking etc.
+        * We put it in unlinked dir to be cleaned up after the scanning
+        */
+       obj =
+           yaffs_FindOrCreateObjectByNumber(dev, objId,
+                                            YAFFS_OBJECT_TYPE_FILE);
+       yaffs_AddObjectToDirectory(dev->unlinkedDir, obj);
+       obj->variant.fileVariant.shrinkSize = 0;
+       obj->valid = 1;         /* So that we don't read any other info for this file */
+
+}
+
+typedef struct {
+       int seq;
+       int block;
+} yaffs_BlockIndex;
+
+
+static void yaffs_HardlinkFixup(yaffs_Device *dev, yaffs_Object *hardList)
+{
+       yaffs_Object *hl;
+       yaffs_Object *in;
+       
+       while (hardList) {
+               hl = hardList;
+               hardList = (yaffs_Object *) (hardList->hardLinks.next);
+
+               in = yaffs_FindObjectByNumber(dev,
+                                             hl->variant.hardLinkVariant.
+                                             equivalentObjectId);
+
+               if (in) {
+                       /* Add the hardlink pointers */
+                       hl->variant.hardLinkVariant.equivalentObject = in;
+                       list_add(&hl->hardLinks, &in->hardLinks);
+               } else {
+                       /* Todo Need to report/handle this better.
+                        * Got a problem... hardlink to a non-existant object
+                        */
+                       hl->variant.hardLinkVariant.equivalentObject = NULL;
+                       INIT_LIST_HEAD(&hl->hardLinks);
+
+               }
+
+       }
+
+}
+
+
+
+
+
+static int ybicmp(const void *a, const void *b){
+    register int aseq = ((yaffs_BlockIndex *)a)->seq;
+    register int bseq = ((yaffs_BlockIndex *)b)->seq;
+    register int ablock = ((yaffs_BlockIndex *)a)->block;
+    register int bblock = ((yaffs_BlockIndex *)b)->block;
+    if( aseq == bseq )
+        return ablock - bblock;
+    else
+        return aseq - bseq;
+
+}
+
+static int yaffs_Scan(yaffs_Device * dev)
+{
+       yaffs_ExtendedTags tags;
+       int blk;
+       int blockIterator;
+       int startIterator;
+       int endIterator;
+       int nBlocksToScan = 0;
+       int result;
+
+       int chunk;
+       int c;
+       int deleted;
+       yaffs_BlockState state;
+       yaffs_Object *hardList = NULL;
+       yaffs_BlockInfo *bi;
+       int sequenceNumber;
+       yaffs_ObjectHeader *oh;
+       yaffs_Object *in;
+       yaffs_Object *parent;
+       int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
+       
+       int alloc_failed = 0;
+       
+
+       __u8 *chunkData;
+
+       yaffs_BlockIndex *blockIndex = NULL;
+
+       if (dev->isYaffs2) {
+               T(YAFFS_TRACE_SCAN,
+                 (TSTR("yaffs_Scan is not for YAFFS2!" TENDSTR)));
+               return YAFFS_FAIL;
+       }
+       
+       //TODO  Throw all the yaffs2 stuuf out of yaffs_Scan since it is only for yaffs1 format.
+       
+       T(YAFFS_TRACE_SCAN,
+         (TSTR("yaffs_Scan starts  intstartblk %d intendblk %d..." TENDSTR),
+          dev->internalStartBlock, dev->internalEndBlock));
+
+       chunkData = yaffs_GetTempBuffer(dev, __LINE__);
+
+       dev->sequenceNumber = YAFFS_LOWEST_SEQUENCE_NUMBER;
+
+       if (dev->isYaffs2) {
+               blockIndex = YMALLOC(nBlocks * sizeof(yaffs_BlockIndex));
+               if(!blockIndex)
+                       return YAFFS_FAIL;
+       }
+
+       /* Scan all the blocks to determine their state */
+       for (blk = dev->internalStartBlock; blk <= dev->internalEndBlock; blk++) {
+               bi = yaffs_GetBlockInfo(dev, blk);
+               yaffs_ClearChunkBits(dev, blk);
+               bi->pagesInUse = 0;
+               bi->softDeletions = 0;
+
+               yaffs_QueryInitialBlockState(dev, blk, &state, &sequenceNumber);
+
+               bi->blockState = state;
+               bi->sequenceNumber = sequenceNumber;
+
+               T(YAFFS_TRACE_SCAN_DEBUG,
+                 (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
+                  state, sequenceNumber));
+
+               if (state == YAFFS_BLOCK_STATE_DEAD) {
+                       T(YAFFS_TRACE_BAD_BLOCKS,
+                         (TSTR("block %d is bad" TENDSTR), blk));
+               } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
+                       T(YAFFS_TRACE_SCAN_DEBUG,
+                         (TSTR("Block empty " TENDSTR)));
+                       dev->nErasedBlocks++;
+                       dev->nFreeChunks += dev->nChunksPerBlock;
+               } else if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+
+                       /* Determine the highest sequence number */
+                       if (dev->isYaffs2 &&
+                           sequenceNumber >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
+                           sequenceNumber < YAFFS_HIGHEST_SEQUENCE_NUMBER) {
+
+                               blockIndex[nBlocksToScan].seq = sequenceNumber;
+                               blockIndex[nBlocksToScan].block = blk;
+
+                               nBlocksToScan++;
+
+                               if (sequenceNumber >= dev->sequenceNumber) {
+                                       dev->sequenceNumber = sequenceNumber;
+                               }
+                       } else if (dev->isYaffs2) {
+                               /* TODO: Nasty sequence number! */
+                               T(YAFFS_TRACE_SCAN,
+                                 (TSTR
+                                  ("Block scanning block %d has bad sequence number %d"
+                                   TENDSTR), blk, sequenceNumber));
+
+                       }
+               }
+       }
+
+       /* Sort the blocks
+        * Dungy old bubble sort for now...
+        */
+       if (dev->isYaffs2) {
+               yaffs_BlockIndex temp;
+               int i;
+               int j;
+
+               for (i = 0; i < nBlocksToScan; i++)
+                       for (j = i + 1; j < nBlocksToScan; j++)
+                               if (blockIndex[i].seq > blockIndex[j].seq) {
+                                       temp = blockIndex[j];
+                                       blockIndex[j] = blockIndex[i];
+                                       blockIndex[i] = temp;
+                               }
+       }
+
+       /* Now scan the blocks looking at the data. */
+       if (dev->isYaffs2) {
+               startIterator = 0;
+               endIterator = nBlocksToScan - 1;
+               T(YAFFS_TRACE_SCAN_DEBUG,
+                 (TSTR("%d blocks to be scanned" TENDSTR), nBlocksToScan));
+       } else {
+               startIterator = dev->internalStartBlock;
+               endIterator = dev->internalEndBlock;
+       }
+
+       /* For each block.... */
+       for (blockIterator = startIterator; !alloc_failed && blockIterator <= endIterator;
+            blockIterator++) {
+
+               if (dev->isYaffs2) {
+                       /* get the block to scan in the correct order */
+                       blk = blockIndex[blockIterator].block;
+               } else {
+                       blk = blockIterator;
+               }
+
+               bi = yaffs_GetBlockInfo(dev, blk);
+               state = bi->blockState;
+
+               deleted = 0;
+
+               /* For each chunk in each block that needs scanning....*/
+               for (c = 0; !alloc_failed && c < dev->nChunksPerBlock &&
+                    state == YAFFS_BLOCK_STATE_NEEDS_SCANNING; c++) {
+                       /* Read the tags and decide what to do */
+                       chunk = blk * dev->nChunksPerBlock + c;
+
+                       result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk, NULL,
+                                                       &tags);
+
+                       /* Let's have a good look at this chunk... */
+
+                       if (!dev->isYaffs2 && tags.chunkDeleted) {
+                               /* YAFFS1 only...
+                                * A deleted chunk
+                                */
+                               deleted++;
+                               dev->nFreeChunks++;
+                               /*T((" %d %d deleted\n",blk,c)); */
+                       } else if (!tags.chunkUsed) {
+                               /* An unassigned chunk in the block
+                                * This means that either the block is empty or 
+                                * this is the one being allocated from
+                                */
+
+                               if (c == 0) {
+                                       /* We're looking at the first chunk in the block so the block is unused */
+                                       state = YAFFS_BLOCK_STATE_EMPTY;
+                                       dev->nErasedBlocks++;
+                               } else {
+                                       /* this is the block being allocated from */
+                                       T(YAFFS_TRACE_SCAN,
+                                         (TSTR
+                                          (" Allocating from %d %d" TENDSTR),
+                                          blk, c));
+                                       state = YAFFS_BLOCK_STATE_ALLOCATING;
+                                       dev->allocationBlock = blk;
+                                       dev->allocationPage = c;
+                                       dev->allocationBlockFinder = blk;       
+                                       /* Set it to here to encourage the allocator to go forth from here. */
+                                       
+                                       /* Yaffs2 sanity check:
+                                        * This should be the one with the highest sequence number
+                                        */
+                                       if (dev->isYaffs2
+                                           && (dev->sequenceNumber !=
+                                               bi->sequenceNumber)) {
+                                               T(YAFFS_TRACE_ALWAYS,
+                                                 (TSTR
+                                                  ("yaffs: Allocation block %d was not highest sequence id:"
+                                                   " block seq = %d, dev seq = %d"
+                                                   TENDSTR), blk,bi->sequenceNumber,dev->sequenceNumber));
+                                       }
+                               }
+
+                               dev->nFreeChunks += (dev->nChunksPerBlock - c);
+                       } else if (tags.chunkId > 0) {
+                               /* chunkId > 0 so it is a data chunk... */
+                               unsigned int endpos;
+
+                               yaffs_SetChunkBit(dev, blk, c);
+                               bi->pagesInUse++;
+
+                               in = yaffs_FindOrCreateObjectByNumber(dev,
+                                                                     tags.
+                                                                     objectId,
+                                                                     YAFFS_OBJECT_TYPE_FILE);
+                               /* PutChunkIntoFile checks for a clash (two data chunks with
+                                * the same chunkId).
+                                */
+                                
+                               if(!in)
+                                       alloc_failed = 1;
+
+                               if(in){
+                                       if(!yaffs_PutChunkIntoFile(in, tags.chunkId, chunk,1))
+                                               alloc_failed = 1;
+                               }
+                               
+                               endpos =
+                                   (tags.chunkId - 1) * dev->nDataBytesPerChunk +
+                                   tags.byteCount;
+                               if (in && 
+                                   in->variantType == YAFFS_OBJECT_TYPE_FILE
+                                   && in->variant.fileVariant.scannedFileSize <
+                                   endpos) {
+                                       in->variant.fileVariant.
+                                           scannedFileSize = endpos;
+                                       if (!dev->useHeaderFileSize) {
+                                               in->variant.fileVariant.
+                                                   fileSize =
+                                                   in->variant.fileVariant.
+                                                   scannedFileSize;
+                                       }
+
+                               }
+                               /* T((" %d %d data %d %d\n",blk,c,tags.objectId,tags.chunkId));   */
+                       } else {
+                               /* chunkId == 0, so it is an ObjectHeader.
+                                * Thus, we read in the object header and make the object
+                                */
+                               yaffs_SetChunkBit(dev, blk, c);
+                               bi->pagesInUse++;
+
+                               result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk,
+                                                               chunkData,
+                                                               NULL);
+
+                               oh = (yaffs_ObjectHeader *) chunkData;
+
+                               in = yaffs_FindObjectByNumber(dev,
+                                                             tags.objectId);
+                               if (in && in->variantType != oh->type) {
+                                       /* This should not happen, but somehow
+                                        * Wev'e ended up with an objectId that has been reused but not yet 
+                                        * deleted, and worse still it has changed type. Delete the old object.
+                                        */
+
+                                       yaffs_DestroyObject(in);
+
+                                       in = 0;
+                               }
+
+                               in = yaffs_FindOrCreateObjectByNumber(dev,
+                                                                     tags.
+                                                                     objectId,
+                                                                     oh->type);
+
+                               if(!in)
+                                       alloc_failed = 1;
+                                       
+                               if (in && oh->shadowsObject > 0) {
+                                       yaffs_HandleShadowedObject(dev,
+                                                                  oh->
+                                                                  shadowsObject,
+                                                                  0);
+                               }
+
+                               if (in && in->valid) {
+                                       /* We have already filled this one. We have a duplicate and need to resolve it. */
+
+                                       unsigned existingSerial = in->serial;
+                                       unsigned newSerial = tags.serialNumber;
+
+                                       if (dev->isYaffs2 ||
+                                           ((existingSerial + 1) & 3) ==
+                                           newSerial) {
+                                               /* Use new one - destroy the exisiting one */
+                                               yaffs_DeleteChunk(dev,
+                                                                 in->chunkId,
+                                                                 1, __LINE__);
+                                               in->valid = 0;
+                                       } else {
+                                               /* Use existing - destroy this one. */
+                                               yaffs_DeleteChunk(dev, chunk, 1,
+                                                                 __LINE__);
+                                       }
+                               }
+
+                               if (in && !in->valid &&
+                                   (tags.objectId == YAFFS_OBJECTID_ROOT ||
+                                    tags.objectId == YAFFS_OBJECTID_LOSTNFOUND)) {
+                                       /* We only load some info, don't fiddle with directory structure */
+                                       in->valid = 1;
+                                       in->variantType = oh->type;
+
+                                       in->yst_mode = oh->yst_mode;
+#ifdef CONFIG_YAFFS_WINCE
+                                       in->win_atime[0] = oh->win_atime[0];
+                                       in->win_ctime[0] = oh->win_ctime[0];
+                                       in->win_mtime[0] = oh->win_mtime[0];
+                                       in->win_atime[1] = oh->win_atime[1];
+                                       in->win_ctime[1] = oh->win_ctime[1];
+                                       in->win_mtime[1] = oh->win_mtime[1];
+#else
+                                       in->yst_uid = oh->yst_uid;
+                                       in->yst_gid = oh->yst_gid;
+                                       in->yst_atime = oh->yst_atime;
+                                       in->yst_mtime = oh->yst_mtime;
+                                       in->yst_ctime = oh->yst_ctime;
+                                       in->yst_rdev = oh->yst_rdev;
+#endif
+                                       in->chunkId = chunk;
+
+                               } else if (in && !in->valid) {
+                                       /* we need to load this info */
+
+                                       in->valid = 1;
+                                       in->variantType = oh->type;
+
+                                       in->yst_mode = oh->yst_mode;
+#ifdef CONFIG_YAFFS_WINCE
+                                       in->win_atime[0] = oh->win_atime[0];
+                                       in->win_ctime[0] = oh->win_ctime[0];
+                                       in->win_mtime[0] = oh->win_mtime[0];
+                                       in->win_atime[1] = oh->win_atime[1];
+                                       in->win_ctime[1] = oh->win_ctime[1];
+                                       in->win_mtime[1] = oh->win_mtime[1];
+#else
+                                       in->yst_uid = oh->yst_uid;
+                                       in->yst_gid = oh->yst_gid;
+                                       in->yst_atime = oh->yst_atime;
+                                       in->yst_mtime = oh->yst_mtime;
+                                       in->yst_ctime = oh->yst_ctime;
+                                       in->yst_rdev = oh->yst_rdev;
+#endif
+                                       in->chunkId = chunk;
+
+                                       yaffs_SetObjectName(in, oh->name);
+                                       in->dirty = 0;
+
+                                       /* directory stuff...
+                                        * hook up to parent
+                                        */
+
+                                       parent =
+                                           yaffs_FindOrCreateObjectByNumber
+                                           (dev, oh->parentObjectId,
+                                            YAFFS_OBJECT_TYPE_DIRECTORY);
+                                       if (parent->variantType ==
+                                           YAFFS_OBJECT_TYPE_UNKNOWN) {
+                                               /* Set up as a directory */
+                                               parent->variantType =
+                                                   YAFFS_OBJECT_TYPE_DIRECTORY;
+                                               INIT_LIST_HEAD(&parent->variant.
+                                                              directoryVariant.
+                                                              children);
+                                       } else if (parent->variantType !=
+                                                  YAFFS_OBJECT_TYPE_DIRECTORY)
+                                       {
+                                               /* Hoosterman, another problem....
+                                                * We're trying to use a non-directory as a directory
+                                                */
+
+                                               T(YAFFS_TRACE_ERROR,
+                                                 (TSTR
+                                                  ("yaffs tragedy: attempting to use non-directory as"
+                                                   " a directory in scan. Put in lost+found."
+                                                   TENDSTR)));
+                                               parent = dev->lostNFoundDir;
+                                       }
+
+                                       yaffs_AddObjectToDirectory(parent, in);
+
+                                       if (0 && (parent == dev->deletedDir ||
+                                                 parent == dev->unlinkedDir)) {
+                                               in->deleted = 1;        /* If it is unlinked at start up then it wants deleting */
+                                               dev->nDeletedFiles++;
+                                       }
+                                       /* Note re hardlinks.
+                                        * Since we might scan a hardlink before its equivalent object is scanned
+                                        * we put them all in a list.
+                                        * After scanning is complete, we should have all the objects, so we run through this
+                                        * list and fix up all the chains.              
+                                        */
+
+                                       switch (in->variantType) {
+                                       case YAFFS_OBJECT_TYPE_UNKNOWN: 
+                                               /* Todo got a problem */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_FILE:
+                                               if (dev->isYaffs2
+                                                   && oh->isShrink) {
+                                                       /* Prune back the shrunken chunks */
+                                                       yaffs_PruneResizedChunks
+                                                           (in, oh->fileSize);
+                                                       /* Mark the block as having a shrinkHeader */
+                                                       bi->hasShrinkHeader = 1;
+                                               }
+
+                                               if (dev->useHeaderFileSize)
+
+                                                       in->variant.fileVariant.
+                                                           fileSize =
+                                                           oh->fileSize;
+
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_HARDLINK:
+                                               in->variant.hardLinkVariant.
+                                                   equivalentObjectId =
+                                                   oh->equivalentObjectId;
+                                               in->hardLinks.next =
+                                                   (struct list_head *)
+                                                   hardList;
+                                               hardList = in;
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_DIRECTORY:
+                                               /* Do nothing */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_SPECIAL:
+                                               /* Do nothing */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_SYMLINK: 
+                                               in->variant.symLinkVariant.alias =
+                                                   yaffs_CloneString(oh->alias);
+                                               if(!in->variant.symLinkVariant.alias)
+                                                       alloc_failed = 1;
+                                               break;
+                                       }
+
+                                       if (parent == dev->deletedDir) {
+                                               yaffs_DestroyObject(in);
+                                               bi->hasShrinkHeader = 1;
+                                       }
+                               }
+                       }
+               }
+
+               if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                       /* If we got this far while scanning, then the block is fully allocated.*/
+                       state = YAFFS_BLOCK_STATE_FULL;
+               }
+
+               bi->blockState = state;
+
+               /* Now let's see if it was dirty */
+               if (bi->pagesInUse == 0 &&
+                   !bi->hasShrinkHeader &&
+                   bi->blockState == YAFFS_BLOCK_STATE_FULL) {
+                       yaffs_BlockBecameDirty(dev, blk);
+               }
+
+       }
+
+       if (blockIndex) {
+               YFREE(blockIndex);
+       }
+       
+       
+       /* Ok, we've done all the scanning.
+        * Fix up the hard link chains.
+        * We should now have scanned all the objects, now it's time to add these 
+        * hardlinks.
+        */
+
+       yaffs_HardlinkFixup(dev,hardList);
+
+       /* Handle the unlinked files. Since they were left in an unlinked state we should
+        * just delete them.
+        */
+       {
+               struct list_head *i;
+               struct list_head *n;
+
+               yaffs_Object *l;
+               /* Soft delete all the unlinked files */
+               list_for_each_safe(i, n,
+                                  &dev->unlinkedDir->variant.directoryVariant.
+                                  children) {
+                       if (i) {
+                               l = list_entry(i, yaffs_Object, siblings);
+                               yaffs_DestroyObject(l);
+                       }
+               }
+       }
+
+       yaffs_ReleaseTempBuffer(dev, chunkData, __LINE__);
+
+       if(alloc_failed){
+               return YAFFS_FAIL;
+       }
+       
+       T(YAFFS_TRACE_SCAN, (TSTR("yaffs_Scan ends" TENDSTR)));
+       
+
+       return YAFFS_OK;
+}
+
+static void yaffs_CheckObjectDetailsLoaded(yaffs_Object *in)
+{
+       __u8 *chunkData;
+       yaffs_ObjectHeader *oh;
+       yaffs_Device *dev = in->myDev;
+       yaffs_ExtendedTags tags;
+       int result;
+       int alloc_failed = 0;
+
+       if(!in)
+               return;
+               
+#if 0
+       T(YAFFS_TRACE_SCAN,(TSTR("details for object %d %s loaded" TENDSTR),
+               in->objectId,
+               in->lazyLoaded ? "not yet" : "already"));
+#endif
+
+       if(in->lazyLoaded){
+               in->lazyLoaded = 0;
+               chunkData = yaffs_GetTempBuffer(dev, __LINE__);
+
+               result = yaffs_ReadChunkWithTagsFromNAND(dev,in->chunkId,chunkData,&tags);
+               oh = (yaffs_ObjectHeader *) chunkData;          
+
+               in->yst_mode = oh->yst_mode;
+#ifdef CONFIG_YAFFS_WINCE
+               in->win_atime[0] = oh->win_atime[0];
+               in->win_ctime[0] = oh->win_ctime[0];
+               in->win_mtime[0] = oh->win_mtime[0];
+               in->win_atime[1] = oh->win_atime[1];
+               in->win_ctime[1] = oh->win_ctime[1];
+               in->win_mtime[1] = oh->win_mtime[1];
+#else
+               in->yst_uid = oh->yst_uid;
+               in->yst_gid = oh->yst_gid;
+               in->yst_atime = oh->yst_atime;
+               in->yst_mtime = oh->yst_mtime;
+               in->yst_ctime = oh->yst_ctime;
+               in->yst_rdev = oh->yst_rdev;
+               
+#endif
+               yaffs_SetObjectName(in, oh->name);
+               
+               if(in->variantType == YAFFS_OBJECT_TYPE_SYMLINK){
+                        in->variant.symLinkVariant.alias =
+                                                   yaffs_CloneString(oh->alias);
+                       if(!in->variant.symLinkVariant.alias)
+                               alloc_failed = 1; /* Not returned to caller */
+               }
+                                                   
+               yaffs_ReleaseTempBuffer(dev,chunkData, __LINE__);
+       }
+}
+
+static int yaffs_ScanBackwards(yaffs_Device * dev)
+{
+       yaffs_ExtendedTags tags;
+       int blk;
+       int blockIterator;
+       int startIterator;
+       int endIterator;
+       int nBlocksToScan = 0;
+
+       int chunk;
+       int result;
+       int c;
+       int deleted;
+       yaffs_BlockState state;
+       yaffs_Object *hardList = NULL;
+       yaffs_BlockInfo *bi;
+       int sequenceNumber;
+       yaffs_ObjectHeader *oh;
+       yaffs_Object *in;
+       yaffs_Object *parent;
+       int nBlocks = dev->internalEndBlock - dev->internalStartBlock + 1;
+       int itsUnlinked;
+       __u8 *chunkData;
+       
+       int fileSize;
+       int isShrink;
+       int foundChunksInBlock;
+       int equivalentObjectId;
+       int alloc_failed = 0;
+       
+
+       yaffs_BlockIndex *blockIndex = NULL;
+       int altBlockIndex = 0;
+
+       if (!dev->isYaffs2) {
+               T(YAFFS_TRACE_SCAN,
+                 (TSTR("yaffs_ScanBackwards is only for YAFFS2!" TENDSTR)));
+               return YAFFS_FAIL;
+       }
+
+       T(YAFFS_TRACE_SCAN,
+         (TSTR
+          ("yaffs_ScanBackwards starts  intstartblk %d intendblk %d..."
+           TENDSTR), dev->internalStartBlock, dev->internalEndBlock));
+
+
+       dev->sequenceNumber = YAFFS_LOWEST_SEQUENCE_NUMBER;
+
+       blockIndex = YMALLOC(nBlocks * sizeof(yaffs_BlockIndex));
+       
+       if(!blockIndex) {
+               blockIndex = YMALLOC_ALT(nBlocks * sizeof(yaffs_BlockIndex));
+               altBlockIndex = 1;
+       }
+       
+       if(!blockIndex) {
+               T(YAFFS_TRACE_SCAN,
+                 (TSTR("yaffs_Scan() could not allocate block index!" TENDSTR)));
+               return YAFFS_FAIL;
+       }
+       
+       dev->blocksInCheckpoint = 0;
+       
+       chunkData = yaffs_GetTempBuffer(dev, __LINE__);
+
+       /* Scan all the blocks to determine their state */
+       for (blk = dev->internalStartBlock; blk <= dev->internalEndBlock; blk++) {
+               bi = yaffs_GetBlockInfo(dev, blk);
+               yaffs_ClearChunkBits(dev, blk);
+               bi->pagesInUse = 0;
+               bi->softDeletions = 0;
+
+               yaffs_QueryInitialBlockState(dev, blk, &state, &sequenceNumber);
+
+               bi->blockState = state;
+               bi->sequenceNumber = sequenceNumber;
+
+               if(bi->sequenceNumber == YAFFS_SEQUENCE_CHECKPOINT_DATA)
+                       bi->blockState = state = YAFFS_BLOCK_STATE_CHECKPOINT;
+                       
+               T(YAFFS_TRACE_SCAN_DEBUG,
+                 (TSTR("Block scanning block %d state %d seq %d" TENDSTR), blk,
+                  state, sequenceNumber));
+
+               
+               if(state == YAFFS_BLOCK_STATE_CHECKPOINT){
+                       dev->blocksInCheckpoint++;
+                       
+               } else if (state == YAFFS_BLOCK_STATE_DEAD) {
+                       T(YAFFS_TRACE_BAD_BLOCKS,
+                         (TSTR("block %d is bad" TENDSTR), blk));
+               } else if (state == YAFFS_BLOCK_STATE_EMPTY) {
+                       T(YAFFS_TRACE_SCAN_DEBUG,
+                         (TSTR("Block empty " TENDSTR)));
+                       dev->nErasedBlocks++;
+                       dev->nFreeChunks += dev->nChunksPerBlock;
+               } else if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+
+                       /* Determine the highest sequence number */
+                       if (dev->isYaffs2 &&
+                           sequenceNumber >= YAFFS_LOWEST_SEQUENCE_NUMBER &&
+                           sequenceNumber < YAFFS_HIGHEST_SEQUENCE_NUMBER) {
+
+                               blockIndex[nBlocksToScan].seq = sequenceNumber;
+                               blockIndex[nBlocksToScan].block = blk;
+
+                               nBlocksToScan++;
+
+                               if (sequenceNumber >= dev->sequenceNumber) {
+                                       dev->sequenceNumber = sequenceNumber;
+                               }
+                       } else if (dev->isYaffs2) {
+                               /* TODO: Nasty sequence number! */
+                               T(YAFFS_TRACE_SCAN,
+                                 (TSTR
+                                  ("Block scanning block %d has bad sequence number %d"
+                                   TENDSTR), blk, sequenceNumber));
+
+                       }
+               }
+       }
+
+       T(YAFFS_TRACE_SCAN,
+       (TSTR("%d blocks to be sorted..." TENDSTR), nBlocksToScan));
+
+
+
+       YYIELD();
+
+       /* Sort the blocks */
+#ifndef CONFIG_YAFFS_USE_OWN_SORT
+       yaffs_qsort(blockIndex, nBlocksToScan,
+               sizeof(yaffs_BlockIndex), ybicmp);
+#else
+       {
+               /* Dungy old bubble sort... */
+               
+               yaffs_BlockIndex temp;
+               int i;
+               int j;
+
+               for (i = 0; i < nBlocksToScan; i++)
+                       for (j = i + 1; j < nBlocksToScan; j++)
+                               if (blockIndex[i].seq > blockIndex[j].seq) {
+                                       temp = blockIndex[j];
+                                       blockIndex[j] = blockIndex[i];
+                                       blockIndex[i] = temp;
+                               }
+       }
+#endif
+
+       YYIELD();
+
+       T(YAFFS_TRACE_SCAN, (TSTR("...done" TENDSTR)));
+
+       /* Now scan the blocks looking at the data. */
+       startIterator = 0;
+       endIterator = nBlocksToScan - 1;
+       T(YAFFS_TRACE_SCAN_DEBUG,
+         (TSTR("%d blocks to be scanned" TENDSTR), nBlocksToScan));
+
+       /* For each block.... backwards */
+       for (blockIterator = endIterator; !alloc_failed && blockIterator >= startIterator;
+            blockIterator--) {
+               /* Cooperative multitasking! This loop can run for so
+                  long that watchdog timers expire. */
+               YYIELD();
+
+               /* get the block to scan in the correct order */
+               blk = blockIndex[blockIterator].block;
+
+               bi = yaffs_GetBlockInfo(dev, blk);
+               
+               
+               state = bi->blockState;
+
+               deleted = 0;
+
+               /* For each chunk in each block that needs scanning.... */
+               foundChunksInBlock = 0;
+               for (c = dev->nChunksPerBlock - 1; 
+                    !alloc_failed && c >= 0 &&
+                    (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
+                     state == YAFFS_BLOCK_STATE_ALLOCATING); c--) {
+                       /* Scan backwards... 
+                        * Read the tags and decide what to do
+                        */
+                       
+                       chunk = blk * dev->nChunksPerBlock + c;
+
+                       result = yaffs_ReadChunkWithTagsFromNAND(dev, chunk, NULL,
+                                                       &tags);
+
+                       /* Let's have a good look at this chunk... */
+
+                       if (!tags.chunkUsed) {
+                               /* An unassigned chunk in the block.
+                                * If there are used chunks after this one, then
+                                * it is a chunk that was skipped due to failing the erased
+                                * check. Just skip it so that it can be deleted.
+                                * But, more typically, We get here when this is an unallocated
+                                * chunk and his means that either the block is empty or 
+                                * this is the one being allocated from
+                                */
+
+                               if(foundChunksInBlock)
+                               {
+                                       /* This is a chunk that was skipped due to failing the erased check */
+                                       
+                               } else if (c == 0) {
+                                       /* We're looking at the first chunk in the block so the block is unused */
+                                       state = YAFFS_BLOCK_STATE_EMPTY;
+                                       dev->nErasedBlocks++;
+                               } else {
+                                       if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING ||
+                                           state == YAFFS_BLOCK_STATE_ALLOCATING) {
+                                               if(dev->sequenceNumber == bi->sequenceNumber) {
+                                                       /* this is the block being allocated from */
+                                               
+                                                       T(YAFFS_TRACE_SCAN,
+                                                         (TSTR
+                                                          (" Allocating from %d %d"
+                                                           TENDSTR), blk, c));
+
+                                                       state = YAFFS_BLOCK_STATE_ALLOCATING;
+                                                       dev->allocationBlock = blk;
+                                                       dev->allocationPage = c;
+                                                       dev->allocationBlockFinder = blk;       
+                                               }
+                                               else {
+                                                       /* This is a partially written block that is not
+                                                        * the current allocation block. This block must have
+                                                        * had a write failure, so set up for retirement.
+                                                        */
+                                                 
+                                                        bi->needsRetiring = 1;
+                                                        bi->gcPrioritise = 1;
+                                                                                                        
+                                                        T(YAFFS_TRACE_ALWAYS,
+                                                        (TSTR("Partially written block %d being set for retirement" TENDSTR),
+                                                        blk));
+                                               }
+
+                                       }
+                                        
+                               }
+
+                               dev->nFreeChunks++;
+                               
+                       } else if (tags.chunkId > 0) {
+                               /* chunkId > 0 so it is a data chunk... */
+                               unsigned int endpos;
+                               __u32 chunkBase =
+                                   (tags.chunkId - 1) * dev->nDataBytesPerChunk;
+                                                               
+                               foundChunksInBlock = 1;
+
+
+                               yaffs_SetChunkBit(dev, blk, c);
+                               bi->pagesInUse++;
+
+                               in = yaffs_FindOrCreateObjectByNumber(dev,
+                                                                     tags.
+                                                                     objectId,
+                                                                     YAFFS_OBJECT_TYPE_FILE);
+                               if(!in){
+                                       /* Out of memory */
+                                       alloc_failed = 1;
+                               }
+                               
+                               if (in &&
+                                   in->variantType == YAFFS_OBJECT_TYPE_FILE
+                                   && chunkBase <
+                                   in->variant.fileVariant.shrinkSize) {
+                                       /* This has not been invalidated by a resize */
+                                       if(!yaffs_PutChunkIntoFile(in, tags.chunkId,
+                                                              chunk, -1)){
+                                               alloc_failed = 1;
+                                       }
+
+                                       /* File size is calculated by looking at the data chunks if we have not 
+                                        * seen an object header yet. Stop this practice once we find an object header.
+                                        */
+                                       endpos =
+                                           (tags.chunkId -
+                                            1) * dev->nDataBytesPerChunk +
+                                           tags.byteCount;
+                                           
+                                       if (!in->valid &&       /* have not got an object header yet */
+                                           in->variant.fileVariant.
+                                           scannedFileSize < endpos) {
+                                               in->variant.fileVariant.
+                                                   scannedFileSize = endpos;
+                                               in->variant.fileVariant.
+                                                   fileSize =
+                                                   in->variant.fileVariant.
+                                                   scannedFileSize;
+                                       }
+
+                               } else if(in) {
+                                       /* This chunk has been invalidated by a resize, so delete */
+                                       yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
+
+                               }
+                       } else {
+                               /* chunkId == 0, so it is an ObjectHeader.
+                                * Thus, we read in the object header and make the object
+                                */
+                               foundChunksInBlock = 1;
+
+                               yaffs_SetChunkBit(dev, blk, c);
+                               bi->pagesInUse++;
+
+                               oh = NULL;
+                               in = NULL;
+
+                               if (tags.extraHeaderInfoAvailable) {
+                                       in = yaffs_FindOrCreateObjectByNumber
+                                           (dev, tags.objectId,
+                                            tags.extraObjectType);
+                               }
+
+                               if (!in ||
+#ifdef CONFIG_YAFFS_DISABLE_LAZY_LOAD
+                                   !in->valid ||
+#endif
+                                   tags.extraShadows ||
+                                   (!in->valid &&
+                                   (tags.objectId == YAFFS_OBJECTID_ROOT ||
+                                    tags.objectId == YAFFS_OBJECTID_LOSTNFOUND))
+                                   ) {
+
+                                       /* If we don't have  valid info then we need to read the chunk
+                                        * TODO In future we can probably defer reading the chunk and 
+                                        * living with invalid data until needed.
+                                        */
+
+                                       result = yaffs_ReadChunkWithTagsFromNAND(dev,
+                                                                       chunk,
+                                                                       chunkData,
+                                                                       NULL);
+
+                                       oh = (yaffs_ObjectHeader *) chunkData;
+
+                                       if (!in)
+                                               in = yaffs_FindOrCreateObjectByNumber(dev, tags.objectId, oh->type);
+
+                               }
+
+                               if (!in) {
+                                       /* TODO Hoosterman we have a problem! */
+                                       T(YAFFS_TRACE_ERROR,
+                                         (TSTR
+                                          ("yaffs tragedy: Could not make object for object  %d  "
+                                           "at chunk %d during scan"
+                                           TENDSTR), tags.objectId, chunk));
+
+                               }
+
+                               if (in->valid) {
+                                       /* We have already filled this one.
+                                        * We have a duplicate that will be discarded, but 
+                                        * we first have to suck out resize info if it is a file.
+                                        */
+
+                                       if ((in->variantType == YAFFS_OBJECT_TYPE_FILE) && 
+                                            ((oh && 
+                                              oh-> type == YAFFS_OBJECT_TYPE_FILE)||
+                                             (tags.extraHeaderInfoAvailable  &&
+                                              tags.extraObjectType == YAFFS_OBJECT_TYPE_FILE))
+                                           ) {
+                                               __u32 thisSize =
+                                                   (oh) ? oh->fileSize : tags.
+                                                   extraFileLength;
+                                               __u32 parentObjectId =
+                                                   (oh) ? oh->
+                                                   parentObjectId : tags.
+                                                   extraParentObjectId;
+                                               unsigned isShrink =
+                                                   (oh) ? oh->isShrink : tags.
+                                                   extraIsShrinkHeader;
+
+                                               /* If it is deleted (unlinked at start also means deleted)
+                                                * we treat the file size as being zeroed at this point.
+                                                */
+                                               if (parentObjectId ==
+                                                   YAFFS_OBJECTID_DELETED
+                                                   || parentObjectId ==
+                                                   YAFFS_OBJECTID_UNLINKED) {
+                                                       thisSize = 0;
+                                                       isShrink = 1;
+                                               }
+
+                                               if (isShrink &&
+                                                   in->variant.fileVariant.
+                                                   shrinkSize > thisSize) {
+                                                       in->variant.fileVariant.
+                                                           shrinkSize =
+                                                           thisSize;
+                                               }
+
+                                               if (isShrink) {
+                                                       bi->hasShrinkHeader = 1;
+                                               }
+
+                                       }
+                                       /* Use existing - destroy this one. */
+                                       yaffs_DeleteChunk(dev, chunk, 1, __LINE__);
+
+                               }
+
+                               if (!in->valid &&
+                                   (tags.objectId == YAFFS_OBJECTID_ROOT ||
+                                    tags.objectId ==
+                                    YAFFS_OBJECTID_LOSTNFOUND)) {
+                                       /* We only load some info, don't fiddle with directory structure */
+                                       in->valid = 1;
+                                       
+                                       if(oh) {
+                                               in->variantType = oh->type;
+
+                                               in->yst_mode = oh->yst_mode;
+#ifdef CONFIG_YAFFS_WINCE
+                                               in->win_atime[0] = oh->win_atime[0];
+                                               in->win_ctime[0] = oh->win_ctime[0];
+                                               in->win_mtime[0] = oh->win_mtime[0];
+                                               in->win_atime[1] = oh->win_atime[1];
+                                               in->win_ctime[1] = oh->win_ctime[1];
+                                               in->win_mtime[1] = oh->win_mtime[1];
+#else
+                                               in->yst_uid = oh->yst_uid;
+                                               in->yst_gid = oh->yst_gid;
+                                               in->yst_atime = oh->yst_atime;
+                                               in->yst_mtime = oh->yst_mtime;
+                                               in->yst_ctime = oh->yst_ctime;
+                                               in->yst_rdev = oh->yst_rdev;
+               
+#endif
+                                       } else {
+                                               in->variantType = tags.extraObjectType;
+                                               in->lazyLoaded = 1;
+                                       }
+                                               
+                                       in->chunkId = chunk;
+
+                               } else if (!in->valid) {
+                                       /* we need to load this info */
+
+                                       in->valid = 1;
+                                       in->chunkId = chunk;
+                                       
+                                       if(oh) {
+                                               in->variantType = oh->type;
+
+                                               in->yst_mode = oh->yst_mode;
+#ifdef CONFIG_YAFFS_WINCE
+                                               in->win_atime[0] = oh->win_atime[0];
+                                               in->win_ctime[0] = oh->win_ctime[0];
+                                               in->win_mtime[0] = oh->win_mtime[0];
+                                               in->win_atime[1] = oh->win_atime[1];
+                                               in->win_ctime[1] = oh->win_ctime[1];
+                                               in->win_mtime[1] = oh->win_mtime[1];
+#else
+                                               in->yst_uid = oh->yst_uid;
+                                               in->yst_gid = oh->yst_gid;
+                                               in->yst_atime = oh->yst_atime;
+                                               in->yst_mtime = oh->yst_mtime;
+                                               in->yst_ctime = oh->yst_ctime;
+                                               in->yst_rdev = oh->yst_rdev;
+#endif
+
+                                               if (oh->shadowsObject > 0) 
+                                                       yaffs_HandleShadowedObject(dev,
+                                                                          oh->
+                                                                          shadowsObject,
+                                                                          1);
+                                       
+
+                                               yaffs_SetObjectName(in, oh->name);
+                                               parent =
+                                                   yaffs_FindOrCreateObjectByNumber
+                                                       (dev, oh->parentObjectId,
+                                                        YAFFS_OBJECT_TYPE_DIRECTORY);
+
+                                                fileSize = oh->fileSize;
+                                                isShrink = oh->isShrink;
+                                                equivalentObjectId = oh->equivalentObjectId;
+
+                                       }
+                                       else {
+                                               in->variantType = tags.extraObjectType;
+                                               parent =
+                                                   yaffs_FindOrCreateObjectByNumber
+                                                       (dev, tags.extraParentObjectId,
+                                                        YAFFS_OBJECT_TYPE_DIRECTORY);
+                                                fileSize = tags.extraFileLength;
+                                                isShrink = tags.extraIsShrinkHeader;
+                                                equivalentObjectId = tags.extraEquivalentObjectId;
+                                               in->lazyLoaded = 1;
+
+                                       }
+                                       in->dirty = 0;
+
+                                       /* directory stuff...
+                                        * hook up to parent
+                                        */
+
+                                       if (parent->variantType ==
+                                           YAFFS_OBJECT_TYPE_UNKNOWN) {
+                                               /* Set up as a directory */
+                                               parent->variantType =
+                                                   YAFFS_OBJECT_TYPE_DIRECTORY;
+                                               INIT_LIST_HEAD(&parent->variant.
+                                                              directoryVariant.
+                                                              children);
+                                       } else if (parent->variantType !=
+                                                  YAFFS_OBJECT_TYPE_DIRECTORY)
+                                       {
+                                               /* Hoosterman, another problem....
+                                                * We're trying to use a non-directory as a directory
+                                                */
+
+                                               T(YAFFS_TRACE_ERROR,
+                                                 (TSTR
+                                                  ("yaffs tragedy: attempting to use non-directory as"
+                                                   " a directory in scan. Put in lost+found."
+                                                   TENDSTR)));
+                                               parent = dev->lostNFoundDir;
+                                       }
+
+                                       yaffs_AddObjectToDirectory(parent, in);
+
+                                       itsUnlinked = (parent == dev->deletedDir) ||
+                                                     (parent == dev->unlinkedDir);
+
+                                       if (isShrink) {
+                                               /* Mark the block as having a shrinkHeader */
+                                               bi->hasShrinkHeader = 1;
+                                       }
+
+                                       /* Note re hardlinks.
+                                        * Since we might scan a hardlink before its equivalent object is scanned
+                                        * we put them all in a list.
+                                        * After scanning is complete, we should have all the objects, so we run
+                                        * through this list and fix up all the chains.              
+                                        */
+
+                                       switch (in->variantType) {
+                                       case YAFFS_OBJECT_TYPE_UNKNOWN: 
+                                               /* Todo got a problem */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_FILE:
+
+                                               if (in->variant.fileVariant.
+                                                   scannedFileSize < fileSize) {
+                                                       /* This covers the case where the file size is greater
+                                                        * than where the data is
+                                                        * This will happen if the file is resized to be larger 
+                                                        * than its current data extents.
+                                                        */
+                                                       in->variant.fileVariant.fileSize = fileSize;
+                                                       in->variant.fileVariant.scannedFileSize =
+                                                           in->variant.fileVariant.fileSize;
+                                               }
+
+                                               if (isShrink &&
+                                                   in->variant.fileVariant.shrinkSize > fileSize) {
+                                                       in->variant.fileVariant.shrinkSize = fileSize;
+                                               }
+
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_HARDLINK:
+                                               if(!itsUnlinked) {
+                                                 in->variant.hardLinkVariant.equivalentObjectId =
+                                                   equivalentObjectId;
+                                                 in->hardLinks.next =
+                                                   (struct list_head *) hardList;
+                                                 hardList = in;
+                                               }
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_DIRECTORY:
+                                               /* Do nothing */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_SPECIAL:
+                                               /* Do nothing */
+                                               break;
+                                       case YAFFS_OBJECT_TYPE_SYMLINK:
+                                               if(oh){
+                                                  in->variant.symLinkVariant.alias =
+                                                   yaffs_CloneString(oh->
+                                                                     alias);
+                                                  if(!in->variant.symLinkVariant.alias)
+                                                       alloc_failed = 1;
+                                               }
+                                               break;
+                                       }
+
+                               }
+                               
+                       }
+
+               } /* End of scanning for each chunk */
+
+               if (state == YAFFS_BLOCK_STATE_NEEDS_SCANNING) {
+                       /* If we got this far while scanning, then the block is fully allocated. */
+                       state = YAFFS_BLOCK_STATE_FULL;
+               }
+
+               bi->blockState = state;
+
+               /* Now let's see if it was dirty */
+               if (bi->pagesInUse == 0 &&
+                   !bi->hasShrinkHeader &&
+                   bi->blockState == YAFFS_BLOCK_STATE_FULL) {
+                       yaffs_BlockBecameDirty(dev, blk);
+               }
+
+       }
+
+       if (altBlockIndex) 
+               YFREE_ALT(blockIndex);
+       else
+               YFREE(blockIndex);
+       
+       /* Ok, we've done all the scanning.
+        * Fix up the hard link chains.
+        * We should now have scanned all the objects, now it's time to add these 
+        * hardlinks.
+        */
+       yaffs_HardlinkFixup(dev,hardList);
+       
+       
+       /*
+       *  Sort out state of unlinked and deleted objects.
+       */
+       {
+               struct list_head *i;
+               struct list_head *n;
+
+               yaffs_Object *l;
+
+               /* Soft delete all the unlinked files */
+               list_for_each_safe(i, n,
+                                  &dev->unlinkedDir->variant.directoryVariant.
+                                  children) {
+                       if (i) {
+                               l = list_entry(i, yaffs_Object, siblings);
+                               yaffs_DestroyObject(l);
+                       }
+               }
+
+               /* Soft delete all the deletedDir files */
+               list_for_each_safe(i, n,
+                                  &dev->deletedDir->variant.directoryVariant.
+                                  children) {
+                       if (i) {
+                               l = list_entry(i, yaffs_Object, siblings);
+                               yaffs_DestroyObject(l);
+
+                       }
+               }
+       }
+
+       yaffs_ReleaseTempBuffer(dev, chunkData, __LINE__);
+       
+       if(alloc_failed){
+               return YAFFS_FAIL;
+       }
+
+       T(YAFFS_TRACE_SCAN, (TSTR("yaffs_ScanBackwards ends" TENDSTR)));
+
+       return YAFFS_OK;
+}
+
+/*------------------------------  Directory Functions ----------------------------- */
+
+static void yaffs_RemoveObjectFromDirectory(yaffs_Object * obj)
+{
+       yaffs_Device *dev = obj->myDev;
+       
+       if(dev && dev->removeObjectCallback)
+               dev->removeObjectCallback(obj);
+          
+       list_del_init(&obj->siblings);
+       obj->parent = NULL;
+}
+
+
+static void yaffs_AddObjectToDirectory(yaffs_Object * directory,
+                                      yaffs_Object * obj)
+{
+
+       if (!directory) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR
+                  ("tragedy: Trying to add an object to a null pointer directory"
+                   TENDSTR)));
+               YBUG();
+       }
+       if (directory->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR
+                  ("tragedy: Trying to add an object to a non-directory"
+                   TENDSTR)));
+               YBUG();
+       }
+
+       if (obj->siblings.prev == NULL) {
+               /* Not initialised */
+               INIT_LIST_HEAD(&obj->siblings);
+
+       } else if (!list_empty(&obj->siblings)) {
+               /* If it is holed up somewhere else, un hook it */
+               yaffs_RemoveObjectFromDirectory(obj);
+       }
+       /* Now add it */
+       list_add(&obj->siblings, &directory->variant.directoryVariant.children);
+       obj->parent = directory;
+
+       if (directory == obj->myDev->unlinkedDir
+           || directory == obj->myDev->deletedDir) {
+               obj->unlinked = 1;
+               obj->myDev->nUnlinkedFiles++;
+               obj->renameAllowed = 0;
+       }
+}
+
+yaffs_Object *yaffs_FindObjectByName(yaffs_Object * directory,
+                                    const YCHAR * name)
+{
+       int sum;
+
+       struct list_head *i;
+       YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
+
+       yaffs_Object *l;
+
+       if (!name) {
+               return NULL;
+       }
+
+       if (!directory) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR
+                  ("tragedy: yaffs_FindObjectByName: null pointer directory"
+                   TENDSTR)));
+               YBUG();
+       }
+       if (directory->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR
+                  ("tragedy: yaffs_FindObjectByName: non-directory" TENDSTR)));
+               YBUG();
+       }
+
+       sum = yaffs_CalcNameSum(name);
+
+       list_for_each(i, &directory->variant.directoryVariant.children) {
+               if (i) {
+                       l = list_entry(i, yaffs_Object, siblings);
+                       
+                       yaffs_CheckObjectDetailsLoaded(l);
+
+                       /* Special case for lost-n-found */
+                       if (l->objectId == YAFFS_OBJECTID_LOSTNFOUND) {
+                               if (yaffs_strcmp(name, YAFFS_LOSTNFOUND_NAME) == 0) {
+                                       return l;
+                               }
+                       } else if (yaffs_SumCompare(l->sum, sum) || l->chunkId <= 0)    
+                       {
+                               /* LostnFound cunk called Objxxx
+                                * Do a real check
+                                */
+                               yaffs_GetObjectName(l, buffer,
+                                                   YAFFS_MAX_NAME_LENGTH);
+                               if (yaffs_strncmp(name, buffer,YAFFS_MAX_NAME_LENGTH) == 0) {
+                                       return l;
+                               }
+
+                       }
+               }
+       }
+
+       return NULL;
+}
+
+
+#if 0
+int yaffs_ApplyToDirectoryChildren(yaffs_Object * theDir,
+                                  int (*fn) (yaffs_Object *))
+{
+       struct list_head *i;
+       yaffs_Object *l;
+
+       if (!theDir) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR
+                  ("tragedy: yaffs_FindObjectByName: null pointer directory"
+                   TENDSTR)));
+               YBUG();
+       }
+       if (theDir->variantType != YAFFS_OBJECT_TYPE_DIRECTORY) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR
+                  ("tragedy: yaffs_FindObjectByName: non-directory" TENDSTR)));
+               YBUG();
+       }
+
+       list_for_each(i, &theDir->variant.directoryVariant.children) {
+               if (i) {
+                       l = list_entry(i, yaffs_Object, siblings);
+                       if (l && !fn(l)) {
+                               return YAFFS_FAIL;
+                       }
+               }
+       }
+
+       return YAFFS_OK;
+
+}
+#endif
+
+/* GetEquivalentObject dereferences any hard links to get to the
+ * actual object.
+ */
+
+yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object * obj)
+{
+       if (obj && obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK) {
+               /* We want the object id of the equivalent object, not this one */
+               obj = obj->variant.hardLinkVariant.equivalentObject;
+               yaffs_CheckObjectDetailsLoaded(obj);
+       }
+       return obj;
+
+}
+
+int yaffs_GetObjectName(yaffs_Object * obj, YCHAR * name, int buffSize)
+{
+       memset(name, 0, buffSize * sizeof(YCHAR));
+       
+       yaffs_CheckObjectDetailsLoaded(obj);
+
+       if (obj->objectId == YAFFS_OBJECTID_LOSTNFOUND) {
+               yaffs_strncpy(name, YAFFS_LOSTNFOUND_NAME, buffSize - 1);
+       } else if (obj->chunkId <= 0) {
+               YCHAR locName[20];
+               /* make up a name */
+               yaffs_sprintf(locName, _Y("%s%d"), YAFFS_LOSTNFOUND_PREFIX,
+                             obj->objectId);
+               yaffs_strncpy(name, locName, buffSize - 1);
+
+       }
+#ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
+       else if (obj->shortName[0]) {
+               yaffs_strcpy(name, obj->shortName);
+       }
+#endif
+       else {
+               int result;
+               __u8 *buffer = yaffs_GetTempBuffer(obj->myDev, __LINE__);
+
+               yaffs_ObjectHeader *oh = (yaffs_ObjectHeader *) buffer;
+
+               memset(buffer, 0, obj->myDev->nDataBytesPerChunk);
+
+               if (obj->chunkId >= 0) {
+                       result = yaffs_ReadChunkWithTagsFromNAND(obj->myDev,
+                                                       obj->chunkId, buffer,
+                                                       NULL);
+               }
+               yaffs_strncpy(name, oh->name, buffSize - 1);
+
+               yaffs_ReleaseTempBuffer(obj->myDev, buffer, __LINE__);
+       }
+
+       return yaffs_strlen(name);
+}
+
+int yaffs_GetObjectFileLength(yaffs_Object * obj)
+{
+
+       /* Dereference any hard linking */
+       obj = yaffs_GetEquivalentObject(obj);
+
+       if (obj->variantType == YAFFS_OBJECT_TYPE_FILE) {
+               return obj->variant.fileVariant.fileSize;
+       }
+       if (obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK) {
+               return yaffs_strlen(obj->variant.symLinkVariant.alias);
+       } else {
+               /* Only a directory should drop through to here */
+               return obj->myDev->nDataBytesPerChunk;
+       }
+}
+
+int yaffs_GetObjectLinkCount(yaffs_Object * obj)
+{
+       int count = 0;
+       struct list_head *i;
+
+       if (!obj->unlinked) {
+               count++;        /* the object itself */
+       }
+       list_for_each(i, &obj->hardLinks) {
+               count++;        /* add the hard links; */
+       }
+       return count;
+
+}
+
+int yaffs_GetObjectInode(yaffs_Object * obj)
+{
+       obj = yaffs_GetEquivalentObject(obj);
+
+       return obj->objectId;
+}
+
+unsigned yaffs_GetObjectType(yaffs_Object * obj)
+{
+       obj = yaffs_GetEquivalentObject(obj);
+
+       switch (obj->variantType) {
+       case YAFFS_OBJECT_TYPE_FILE:
+               return DT_REG;
+               break;
+       case YAFFS_OBJECT_TYPE_DIRECTORY:
+               return DT_DIR;
+               break;
+       case YAFFS_OBJECT_TYPE_SYMLINK:
+               return DT_LNK;
+               break;
+       case YAFFS_OBJECT_TYPE_HARDLINK:
+               return DT_REG;
+               break;
+       case YAFFS_OBJECT_TYPE_SPECIAL:
+               if (S_ISFIFO(obj->yst_mode))
+                       return DT_FIFO;
+               if (S_ISCHR(obj->yst_mode))
+                       return DT_CHR;
+               if (S_ISBLK(obj->yst_mode))
+                       return DT_BLK;
+               if (S_ISSOCK(obj->yst_mode))
+                       return DT_SOCK;
+       default:
+               return DT_REG;
+               break;
+       }
+}
+
+YCHAR *yaffs_GetSymlinkAlias(yaffs_Object * obj)
+{
+       obj = yaffs_GetEquivalentObject(obj);
+       if (obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK) {
+               return yaffs_CloneString(obj->variant.symLinkVariant.alias);
+       } else {
+               return yaffs_CloneString(_Y(""));
+       }
+}
+
+#ifndef CONFIG_YAFFS_WINCE
+
+int yaffs_SetAttributes(yaffs_Object * obj, struct iattr *attr)
+{
+       unsigned int valid = attr->ia_valid;
+
+       if (valid & ATTR_MODE)
+               obj->yst_mode = attr->ia_mode;
+       if (valid & ATTR_UID)
+               obj->yst_uid = attr->ia_uid;
+       if (valid & ATTR_GID)
+               obj->yst_gid = attr->ia_gid;
+
+       if (valid & ATTR_ATIME)
+               obj->yst_atime = Y_TIME_CONVERT(attr->ia_atime);
+       if (valid & ATTR_CTIME)
+               obj->yst_ctime = Y_TIME_CONVERT(attr->ia_ctime);
+       if (valid & ATTR_MTIME)
+               obj->yst_mtime = Y_TIME_CONVERT(attr->ia_mtime);
+
+       if (valid & ATTR_SIZE)
+               yaffs_ResizeFile(obj, attr->ia_size);
+
+       yaffs_UpdateObjectHeader(obj, NULL, 1, 0, 0);
+
+       return YAFFS_OK;
+
+}
+int yaffs_GetAttributes(yaffs_Object * obj, struct iattr *attr)
+{
+       unsigned int valid = 0;
+
+       attr->ia_mode = obj->yst_mode;
+       valid |= ATTR_MODE;
+       attr->ia_uid = obj->yst_uid;
+       valid |= ATTR_UID;
+       attr->ia_gid = obj->yst_gid;
+       valid |= ATTR_GID;
+
+       Y_TIME_CONVERT(attr->ia_atime) = obj->yst_atime;
+       valid |= ATTR_ATIME;
+       Y_TIME_CONVERT(attr->ia_ctime) = obj->yst_ctime;
+       valid |= ATTR_CTIME;
+       Y_TIME_CONVERT(attr->ia_mtime) = obj->yst_mtime;
+       valid |= ATTR_MTIME;
+
+       attr->ia_size = yaffs_GetFileSize(obj);
+       valid |= ATTR_SIZE;
+
+       attr->ia_valid = valid;
+
+       return YAFFS_OK;
+
+}
+
+#endif
+
+#if 0
+int yaffs_DumpObject(yaffs_Object * obj)
+{
+       YCHAR name[257];
+
+       yaffs_GetObjectName(obj, name, 256);
+
+       T(YAFFS_TRACE_ALWAYS,
+         (TSTR
+          ("Object %d, inode %d \"%s\"\n dirty %d valid %d serial %d sum %d"
+           " chunk %d type %d size %d\n"
+           TENDSTR), obj->objectId, yaffs_GetObjectInode(obj), name,
+          obj->dirty, obj->valid, obj->serial, obj->sum, obj->chunkId,
+          yaffs_GetObjectType(obj), yaffs_GetObjectFileLength(obj)));
+
+       return YAFFS_OK;
+}
+#endif
+
+/*---------------------------- Initialisation code -------------------------------------- */
+
+static int yaffs_CheckDevFunctions(const yaffs_Device * dev)
+{
+
+       /* Common functions, gotta have */
+       if (!dev->eraseBlockInNAND || !dev->initialiseNAND)
+               return 0;
+
+#ifdef CONFIG_YAFFS_YAFFS2
+
+       /* Can use the "with tags" style interface for yaffs1 or yaffs2 */
+       if (dev->writeChunkWithTagsToNAND &&
+           dev->readChunkWithTagsFromNAND &&
+           !dev->writeChunkToNAND &&
+           !dev->readChunkFromNAND &&
+           dev->markNANDBlockBad && dev->queryNANDBlock)
+               return 1;
+#endif
+
+       /* Can use the "spare" style interface for yaffs1 */
+       if (!dev->isYaffs2 &&
+           !dev->writeChunkWithTagsToNAND &&
+           !dev->readChunkWithTagsFromNAND &&
+           dev->writeChunkToNAND &&
+           dev->readChunkFromNAND &&
+           !dev->markNANDBlockBad && !dev->queryNANDBlock)
+               return 1;
+
+       return 0;               /* bad */
+}
+
+
+static int yaffs_CreateInitialDirectories(yaffs_Device *dev)
+{
+       /* Initialise the unlinked, deleted, root and lost and found directories */
+       
+       dev->lostNFoundDir = dev->rootDir =  NULL;
+       dev->unlinkedDir = dev->deletedDir = NULL;
+
+       dev->unlinkedDir =
+           yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_UNLINKED, S_IFDIR);
+       
+       dev->deletedDir =
+           yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_DELETED, S_IFDIR);
+
+       dev->rootDir =
+           yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_ROOT,
+                                     YAFFS_ROOT_MODE | S_IFDIR);
+       dev->lostNFoundDir =
+           yaffs_CreateFakeDirectory(dev, YAFFS_OBJECTID_LOSTNFOUND,
+                                     YAFFS_LOSTNFOUND_MODE | S_IFDIR);
+       
+       if(dev->lostNFoundDir && dev->rootDir && dev->unlinkedDir && dev->deletedDir){
+               yaffs_AddObjectToDirectory(dev->rootDir, dev->lostNFoundDir);
+               return YAFFS_OK;
+       }
+       
+       return YAFFS_FAIL;
+}
+
+int yaffs_GutsInitialise(yaffs_Device * dev)
+{
+       int init_failed = 0;
+       unsigned x;
+       int bits;
+
+       T(YAFFS_TRACE_TRACING, (TSTR("yaffs: yaffs_GutsInitialise()" TENDSTR)));
+
+       /* Check stuff that must be set */
+
+       if (!dev) {
+               T(YAFFS_TRACE_ALWAYS, (TSTR("yaffs: Need a device" TENDSTR)));
+               return YAFFS_FAIL;
+       }
+
+       dev->internalStartBlock = dev->startBlock;
+       dev->internalEndBlock = dev->endBlock;
+       dev->blockOffset = 0;
+       dev->chunkOffset = 0;
+       dev->nFreeChunks = 0;
+
+       if (dev->startBlock == 0) {
+               dev->internalStartBlock = dev->startBlock + 1;
+               dev->internalEndBlock = dev->endBlock + 1;
+               dev->blockOffset = 1;
+               dev->chunkOffset = dev->nChunksPerBlock;
+       }
+
+       /* Check geometry parameters. */
+
+       if ((dev->isYaffs2 && dev->nDataBytesPerChunk < 1024) || 
+           (!dev->isYaffs2 && dev->nDataBytesPerChunk != 512) || 
+            dev->nChunksPerBlock < 2 || 
+            dev->nReservedBlocks < 2 || 
+            dev->internalStartBlock <= 0 || 
+            dev->internalEndBlock <= 0 || 
+            dev->internalEndBlock <= (dev->internalStartBlock + dev->nReservedBlocks + 2)      // otherwise it is too small
+           ) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR
+                  ("yaffs: NAND geometry problems: chunk size %d, type is yaffs%s "
+                   TENDSTR), dev->nDataBytesPerChunk, dev->isYaffs2 ? "2" : ""));
+               return YAFFS_FAIL;
+       }
+
+       if (yaffs_InitialiseNAND(dev) != YAFFS_OK) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR("yaffs: InitialiseNAND failed" TENDSTR)));
+               return YAFFS_FAIL;
+       }
+
+       /* Got the right mix of functions? */
+       if (!yaffs_CheckDevFunctions(dev)) {
+               /* Function missing */
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR
+                  ("yaffs: device function(s) missing or wrong\n" TENDSTR)));
+
+               return YAFFS_FAIL;
+       }
+
+       /* This is really a compilation check. */
+       if (!yaffs_CheckStructures()) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR("yaffs_CheckStructures failed\n" TENDSTR)));
+               return YAFFS_FAIL;
+       }
+
+       if (dev->isMounted) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR("yaffs: device already mounted\n" TENDSTR)));
+               return YAFFS_FAIL;
+       }
+
+       /* Finished with most checks. One or two more checks happen later on too. */
+
+       dev->isMounted = 1;
+
+
+
+       /* OK now calculate a few things for the device */
+       
+       /*
+        *  Calculate all the chunk size manipulation numbers: 
+        */
+        /* Start off assuming it is a power of 2 */
+        dev->chunkShift = ShiftDiv(dev->nDataBytesPerChunk);
+        dev->chunkMask = (1<<dev->chunkShift) - 1;
+
+        if(dev->nDataBytesPerChunk == (dev->chunkMask + 1)){
+               /* Yes it is a power of 2, disable crumbs */
+               dev->crumbMask = 0;
+               dev->crumbShift = 0;
+               dev->crumbsPerChunk = 0;
+        } else {
+               /* Not a power of 2, use crumbs instead */
+               dev->crumbShift = ShiftDiv(sizeof(yaffs_PackedTags2TagsPart));
+               dev->crumbMask = (1<<dev->crumbShift)-1;
+               dev->crumbsPerChunk = dev->nDataBytesPerChunk/(1 << dev->crumbShift);
+               dev->chunkShift = 0;
+               dev->chunkMask = 0;
+       }
+               
+
+       /*
+        * Calculate chunkGroupBits.
+        * We need to find the next power of 2 > than internalEndBlock
+        */
+
+       x = dev->nChunksPerBlock * (dev->internalEndBlock + 1);
+       
+       bits = ShiftsGE(x);
+       
+       /* Set up tnode width if wide tnodes are enabled. */
+       if(!dev->wideTnodesDisabled){
+               /* bits must be even so that we end up with 32-bit words */
+               if(bits & 1)
+                       bits++;
+               if(bits < 16)
+                       dev->tnodeWidth = 16;
+               else
+                       dev->tnodeWidth = bits;
+       }
+       else
+               dev->tnodeWidth = 16;
+ 
+       dev->tnodeMask = (1<<dev->tnodeWidth)-1;
+               
+       /* Level0 Tnodes are 16 bits or wider (if wide tnodes are enabled),
+        * so if the bitwidth of the
+        * chunk range we're using is greater than 16 we need
+        * to figure out chunk shift and chunkGroupSize
+        */
+                
+       if (bits <= dev->tnodeWidth)
+               dev->chunkGroupBits = 0;
+       else
+               dev->chunkGroupBits = bits - dev->tnodeWidth;
+               
+
+       dev->chunkGroupSize = 1 << dev->chunkGroupBits;
+
+       if (dev->nChunksPerBlock < dev->chunkGroupSize) {
+               /* We have a problem because the soft delete won't work if
+                * the chunk group size > chunks per block.
+                * This can be remedied by using larger "virtual blocks".
+                */
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR("yaffs: chunk group too large\n" TENDSTR)));
+
+               return YAFFS_FAIL;
+       }
+
+       /* OK, we've finished verifying the device, lets continue with initialisation */
+
+       /* More device initialisation */
+       dev->garbageCollections = 0;
+       dev->passiveGarbageCollections = 0;
+       dev->currentDirtyChecker = 0;
+       dev->bufferedBlock = -1;
+       dev->doingBufferedBlockRewrite = 0;
+       dev->nDeletedFiles = 0;
+       dev->nBackgroundDeletions = 0;
+       dev->nUnlinkedFiles = 0;
+       dev->eccFixed = 0;
+       dev->eccUnfixed = 0;
+       dev->tagsEccFixed = 0;
+       dev->tagsEccUnfixed = 0;
+       dev->nErasureFailures = 0;
+       dev->nErasedBlocks = 0;
+       dev->isDoingGC = 0;
+       dev->hasPendingPrioritisedGCs = 1; /* Assume the worst for now, will get fixed on first GC */
+
+       /* Initialise temporary buffers and caches. */
+       if(!yaffs_InitialiseTempBuffers(dev))
+               init_failed = 1;
+       
+       dev->srCache = NULL;
+       dev->gcCleanupList = NULL;
+       
+       
+       if (!init_failed &&
+           dev->nShortOpCaches > 0) {
+               int i;
+               __u8 *buf;
+               int srCacheBytes = dev->nShortOpCaches * sizeof(yaffs_ChunkCache);
+
+               if (dev->nShortOpCaches > YAFFS_MAX_SHORT_OP_CACHES) {
+                       dev->nShortOpCaches = YAFFS_MAX_SHORT_OP_CACHES;
+               }
+
+               buf = dev->srCache =  YMALLOC(srCacheBytes);
+                   
+               if(dev->srCache)
+                       memset(dev->srCache,0,srCacheBytes);
+                  
+               for (i = 0; i < dev->nShortOpCaches && buf; i++) {
+                       dev->srCache[i].object = NULL;
+                       dev->srCache[i].lastUse = 0;
+                       dev->srCache[i].dirty = 0;
+                       dev->srCache[i].data = buf = YMALLOC_DMA(dev->nDataBytesPerChunk);
+               }
+               if(!buf)
+                       init_failed = 1;
+                       
+               dev->srLastUse = 0;
+       }
+
+       dev->cacheHits = 0;
+       
+       if(!init_failed){
+               dev->gcCleanupList = YMALLOC(dev->nChunksPerBlock * sizeof(__u32));
+               if(!dev->gcCleanupList)
+                       init_failed = 1;
+       }
+
+       if (dev->isYaffs2) {
+               dev->useHeaderFileSize = 1;
+       }
+       if(!init_failed && !yaffs_InitialiseBlocks(dev))
+               init_failed = 1;
+               
+       yaffs_InitialiseTnodes(dev);
+       yaffs_InitialiseObjects(dev);
+
+       if(!init_failed && !yaffs_CreateInitialDirectories(dev))
+               init_failed = 1;
+
+
+       if(!init_failed){
+               /* Now scan the flash. */
+               if (dev->isYaffs2) {
+                       if(yaffs_CheckpointRestore(dev)) {
+                               T(YAFFS_TRACE_ALWAYS,
+                                 (TSTR("yaffs: restored from checkpoint" TENDSTR)));
+                       } else {
+
+                               /* Clean up the mess caused by an aborted checkpoint load 
+                                * and scan backwards. 
+                                */
+                               yaffs_DeinitialiseBlocks(dev);
+                               yaffs_DeinitialiseTnodes(dev);
+                               yaffs_DeinitialiseObjects(dev);
+                               
+                       
+                               dev->nErasedBlocks = 0;
+                               dev->nFreeChunks = 0;
+                               dev->allocationBlock = -1;
+                               dev->allocationPage = -1;
+                               dev->nDeletedFiles = 0;
+                               dev->nUnlinkedFiles = 0;
+                               dev->nBackgroundDeletions = 0;
+                               dev->oldestDirtySequence = 0;
+
+                               if(!init_failed && !yaffs_InitialiseBlocks(dev))
+                                       init_failed = 1;
+                                       
+                               yaffs_InitialiseTnodes(dev);
+                               yaffs_InitialiseObjects(dev);
+
+                               if(!init_failed && !yaffs_CreateInitialDirectories(dev))
+                                       init_failed = 1;
+
+                               if(!init_failed && !yaffs_ScanBackwards(dev))
+                                       init_failed = 1;
+                       }
+               }else
+                       if(!yaffs_Scan(dev))
+                               init_failed = 1;
+       }
+               
+       if(init_failed){
+               /* Clean up the mess */
+               T(YAFFS_TRACE_TRACING,
+                 (TSTR("yaffs: yaffs_GutsInitialise() aborted.\n" TENDSTR)));
+
+               yaffs_Deinitialise(dev);
+               return YAFFS_FAIL;
+       }
+
+       /* Zero out stats */
+       dev->nPageReads = 0;
+       dev->nPageWrites = 0;
+       dev->nBlockErasures = 0;
+       dev->nGCCopies = 0;
+       dev->nRetriedWrites = 0;
+
+       dev->nRetiredBlocks = 0;
+
+       yaffs_VerifyFreeChunks(dev);
+       yaffs_VerifyBlocks(dev);
+       
+
+       T(YAFFS_TRACE_TRACING,
+         (TSTR("yaffs: yaffs_GutsInitialise() done.\n" TENDSTR)));
+       return YAFFS_OK;
+
+}
+
+void yaffs_Deinitialise(yaffs_Device * dev)
+{
+       if (dev->isMounted) {
+               int i;
+
+               yaffs_DeinitialiseBlocks(dev);
+               yaffs_DeinitialiseTnodes(dev);
+               yaffs_DeinitialiseObjects(dev);
+               if (dev->nShortOpCaches > 0 &&
+                   dev->srCache) {
+
+                       for (i = 0; i < dev->nShortOpCaches; i++) {
+                               if(dev->srCache[i].data)
+                                       YFREE(dev->srCache[i].data);
+                               dev->srCache[i].data = NULL;
+                       }
+
+                       YFREE(dev->srCache);
+                       dev->srCache = NULL;
+               }
+
+               YFREE(dev->gcCleanupList);
+
+               for (i = 0; i < YAFFS_N_TEMP_BUFFERS; i++) {
+                       YFREE(dev->tempBuffer[i].buffer);
+               }
+
+               dev->isMounted = 0;
+       }
+
+}
+
+static int yaffs_CountFreeChunks(yaffs_Device * dev)
+{
+       int nFree;
+       int b;
+
+       yaffs_BlockInfo *blk;
+
+       for (nFree = 0, b = dev->internalStartBlock; b <= dev->internalEndBlock;
+            b++) {
+               blk = yaffs_GetBlockInfo(dev, b);
+
+               switch (blk->blockState) {
+               case YAFFS_BLOCK_STATE_EMPTY:
+               case YAFFS_BLOCK_STATE_ALLOCATING:
+               case YAFFS_BLOCK_STATE_COLLECTING:
+               case YAFFS_BLOCK_STATE_FULL:
+                       nFree +=
+                           (dev->nChunksPerBlock - blk->pagesInUse +
+                            blk->softDeletions);
+                       break;
+               default:
+                       break;
+               }
+
+       }
+
+       return nFree;
+}
+
+int yaffs_GetNumberOfFreeChunks(yaffs_Device * dev)
+{
+       /* This is what we report to the outside world */
+
+       int nFree;
+       int nDirtyCacheChunks;
+       int blocksForCheckpoint;
+
+#if 1
+       nFree = dev->nFreeChunks;
+#else
+       nFree = yaffs_CountFreeChunks(dev);
+#endif
+
+       nFree += dev->nDeletedFiles;
+       
+       /* Now count the number of dirty chunks in the cache and subtract those */
+
+       {
+               int i;
+               for (nDirtyCacheChunks = 0, i = 0; i < dev->nShortOpCaches; i++) {
+                       if (dev->srCache[i].dirty)
+                               nDirtyCacheChunks++;
+               }
+       }
+
+       nFree -= nDirtyCacheChunks;
+
+       nFree -= ((dev->nReservedBlocks + 1) * dev->nChunksPerBlock);
+       
+       /* Now we figure out how much to reserve for the checkpoint and report that... */
+       blocksForCheckpoint = dev->nCheckpointReservedBlocks - dev->blocksInCheckpoint;
+       if(blocksForCheckpoint < 0)
+               blocksForCheckpoint = 0;
+               
+       nFree -= (blocksForCheckpoint * dev->nChunksPerBlock);
+
+       if (nFree < 0)
+               nFree = 0;
+
+       return nFree;
+
+}
+
+static int yaffs_freeVerificationFailures;
+
+static void yaffs_VerifyFreeChunks(yaffs_Device * dev)
+{
+       int counted;
+       int difference;
+       
+       if(yaffs_SkipVerification(dev))
+               return;
+       
+       counted = yaffs_CountFreeChunks(dev);
+
+       difference = dev->nFreeChunks - counted;
+
+       if (difference) {
+               T(YAFFS_TRACE_ALWAYS,
+                 (TSTR("Freechunks verification failure %d %d %d" TENDSTR),
+                  dev->nFreeChunks, counted, difference));
+               yaffs_freeVerificationFailures++;
+       }
+}
+
+/*---------------------------------------- YAFFS test code ----------------------*/
+
+#define yaffs_CheckStruct(structure,syze, name) \
+           if(sizeof(structure) != syze) \
+              { \
+                T(YAFFS_TRACE_ALWAYS,(TSTR("%s should be %d but is %d\n" TENDSTR),\
+                name,syze,sizeof(structure))); \
+                return YAFFS_FAIL; \
+               }
+
+static int yaffs_CheckStructures(void)
+{
+/*      yaffs_CheckStruct(yaffs_Tags,8,"yaffs_Tags") */
+/*      yaffs_CheckStruct(yaffs_TagsUnion,8,"yaffs_TagsUnion") */
+/*      yaffs_CheckStruct(yaffs_Spare,16,"yaffs_Spare") */
+#ifndef CONFIG_YAFFS_TNODE_LIST_DEBUG
+       yaffs_CheckStruct(yaffs_Tnode, 2 * YAFFS_NTNODES_LEVEL0, "yaffs_Tnode")
+#endif
+           yaffs_CheckStruct(yaffs_ObjectHeader, 512, "yaffs_ObjectHeader")
+
+           return YAFFS_OK;
+}
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_guts.h linux-2.6.21.1.new/fs/yaffs2/yaffs_guts.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_guts.h       1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_guts.h   2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,902 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_GUTS_H__
+#define __YAFFS_GUTS_H__
+
+#include "devextras.h"
+#include "yportenv.h"
+
+#define YAFFS_OK       1
+#define YAFFS_FAIL  0
+
+/* Give us a  Y=0x59, 
+ * Give us an A=0x41, 
+ * Give us an FF=0xFF 
+ * Give us an S=0x53
+ * And what have we got... 
+ */
+#define YAFFS_MAGIC                    0x5941FF53
+
+#define YAFFS_NTNODES_LEVEL0           16
+#define YAFFS_TNODES_LEVEL0_BITS       4
+#define YAFFS_TNODES_LEVEL0_MASK       0xf
+
+#define YAFFS_NTNODES_INTERNAL                 (YAFFS_NTNODES_LEVEL0 / 2)
+#define YAFFS_TNODES_INTERNAL_BITS     (YAFFS_TNODES_LEVEL0_BITS - 1)
+#define YAFFS_TNODES_INTERNAL_MASK     0x7
+#define YAFFS_TNODES_MAX_LEVEL         6
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+#define YAFFS_BYTES_PER_SPARE          16
+#define YAFFS_BYTES_PER_CHUNK          512
+#define YAFFS_CHUNK_SIZE_SHIFT         9
+#define YAFFS_CHUNKS_PER_BLOCK         32
+#define YAFFS_BYTES_PER_BLOCK          (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
+#endif
+
+#define YAFFS_MIN_YAFFS2_CHUNK_SIZE    1024
+#define YAFFS_MIN_YAFFS2_SPARE_SIZE    32
+
+#define YAFFS_MAX_CHUNK_ID             0x000FFFFF
+
+#define YAFFS_UNUSED_OBJECT_ID         0x0003FFFF
+
+#define YAFFS_ALLOCATION_NOBJECTS      100
+#define YAFFS_ALLOCATION_NTNODES       100
+#define YAFFS_ALLOCATION_NLINKS                100
+
+#define YAFFS_NOBJECT_BUCKETS          256
+
+
+#define YAFFS_OBJECT_SPACE             0x40000
+
+#define YAFFS_CHECKPOINT_VERSION       3
+
+#ifdef CONFIG_YAFFS_UNICODE
+#define YAFFS_MAX_NAME_LENGTH          127
+#define YAFFS_MAX_ALIAS_LENGTH         79
+#else
+#define YAFFS_MAX_NAME_LENGTH          255
+#define YAFFS_MAX_ALIAS_LENGTH         159
+#endif
+
+#define YAFFS_SHORT_NAME_LENGTH                15
+
+/* Some special object ids for pseudo objects */
+#define YAFFS_OBJECTID_ROOT            1
+#define YAFFS_OBJECTID_LOSTNFOUND      2
+#define YAFFS_OBJECTID_UNLINKED                3
+#define YAFFS_OBJECTID_DELETED         4
+
+/* Sseudo object ids for checkpointing */
+#define YAFFS_OBJECTID_SB_HEADER       0x10
+#define YAFFS_OBJECTID_CHECKPOINT_DATA 0x20
+#define YAFFS_SEQUENCE_CHECKPOINT_DATA  0x21
+
+/* */
+
+#define YAFFS_MAX_SHORT_OP_CACHES      20
+
+#define YAFFS_N_TEMP_BUFFERS           4
+
+/* We limit the number attempts at sucessfully saving a chunk of data.
+ * Small-page devices have 32 pages per block; large-page devices have 64.
+ * Default to something in the order of 5 to 10 blocks worth of chunks.
+ */
+#define YAFFS_WR_ATTEMPTS              (5*64)
+
+/* Sequence numbers are used in YAFFS2 to determine block allocation order.
+ * The range is limited slightly to help distinguish bad numbers from good.
+ * This also allows us to perhaps in the future use special numbers for
+ * special purposes.
+ * EFFFFF00 allows the allocation of 8 blocks per second (~1Mbytes) for 15 years, 
+ * and is a larger number than the lifetime of a 2GB device.
+ */
+#define YAFFS_LOWEST_SEQUENCE_NUMBER   0x00001000
+#define YAFFS_HIGHEST_SEQUENCE_NUMBER  0xEFFFFF00
+
+/* ChunkCache is used for short read/write operations.*/
+typedef struct {
+       struct yaffs_ObjectStruct *object;
+       int chunkId;
+       int lastUse;
+       int dirty;
+       int nBytes;             /* Only valid if the cache is dirty */
+       int locked;             /* Can't push out or flush while locked. */
+#ifdef CONFIG_YAFFS_YAFFS2
+       __u8 *data;
+#else
+       __u8 data[YAFFS_BYTES_PER_CHUNK];
+#endif
+} yaffs_ChunkCache;
+
+
+
+/* Tags structures in RAM
+ * NB This uses bitfield. Bitfields should not straddle a u32 boundary otherwise
+ * the structure size will get blown out.
+ */
+
+#ifndef CONFIG_YAFFS_NO_YAFFS1
+typedef struct {
+       unsigned chunkId:20;
+       unsigned serialNumber:2;
+       unsigned byteCount:10;
+       unsigned objectId:18;
+       unsigned ecc:12;
+       unsigned unusedStuff:2;
+
+} yaffs_Tags;
+
+typedef union {
+       yaffs_Tags asTags;
+       __u8 asBytes[8];
+} yaffs_TagsUnion;
+
+#endif
+
+/* Stuff used for extended tags in YAFFS2 */
+
+typedef enum {
+       YAFFS_ECC_RESULT_UNKNOWN,
+       YAFFS_ECC_RESULT_NO_ERROR,
+       YAFFS_ECC_RESULT_FIXED,
+       YAFFS_ECC_RESULT_UNFIXED
+} yaffs_ECCResult;
+
+typedef enum {
+       YAFFS_OBJECT_TYPE_UNKNOWN,
+       YAFFS_OBJECT_TYPE_FILE,
+       YAFFS_OBJECT_TYPE_SYMLINK,
+       YAFFS_OBJECT_TYPE_DIRECTORY,
+       YAFFS_OBJECT_TYPE_HARDLINK,
+       YAFFS_OBJECT_TYPE_SPECIAL
+} yaffs_ObjectType;
+
+#define YAFFS_OBJECT_TYPE_MAX YAFFS_OBJECT_TYPE_SPECIAL
+
+typedef struct {
+
+       unsigned validMarker0;
+       unsigned chunkUsed;     /*  Status of the chunk: used or unused */
+       unsigned objectId;      /* If 0 then this is not part of an object (unused) */
+       unsigned chunkId;       /* If 0 then this is a header, else a data chunk */
+       unsigned byteCount;     /* Only valid for data chunks */
+
+       /* The following stuff only has meaning when we read */
+       yaffs_ECCResult eccResult;
+       unsigned blockBad;      
+
+       /* YAFFS 1 stuff */
+       unsigned chunkDeleted;  /* The chunk is marked deleted */
+       unsigned serialNumber;  /* Yaffs1 2-bit serial number */
+
+       /* YAFFS2 stuff */
+       unsigned sequenceNumber;        /* The sequence number of this block */
+
+       /* Extra info if this is an object header (YAFFS2 only) */
+
+       unsigned extraHeaderInfoAvailable;      /* There is extra info available if this is not zero */
+       unsigned extraParentObjectId;   /* The parent object */
+       unsigned extraIsShrinkHeader;   /* Is it a shrink header? */
+       unsigned extraShadows;          /* Does this shadow another object? */
+
+       yaffs_ObjectType extraObjectType;       /* What object type? */
+
+       unsigned extraFileLength;               /* Length if it is a file */
+       unsigned extraEquivalentObjectId;       /* Equivalent object Id if it is a hard link */
+
+       unsigned validMarker1;
+
+} yaffs_ExtendedTags;
+
+/* Spare structure for YAFFS1 */
+typedef struct {
+       __u8 tagByte0;
+       __u8 tagByte1;
+       __u8 tagByte2;
+       __u8 tagByte3;
+       __u8 pageStatus;        /* set to 0 to delete the chunk */
+       __u8 blockStatus;
+       __u8 tagByte4;
+       __u8 tagByte5;
+       __u8 ecc1[3];
+       __u8 tagByte6;
+       __u8 tagByte7;
+       __u8 ecc2[3];
+} yaffs_Spare;
+
+/*Special structure for passing through to mtd */
+struct yaffs_NANDSpare {
+       yaffs_Spare spare;
+       int eccres1;
+       int eccres2;
+};
+
+/* Block data in RAM */
+
+typedef enum {
+       YAFFS_BLOCK_STATE_UNKNOWN = 0,
+
+       YAFFS_BLOCK_STATE_SCANNING,
+       YAFFS_BLOCK_STATE_NEEDS_SCANNING,
+       /* The block might have something on it (ie it is allocating or full, perhaps empty)
+        * but it needs to be scanned to determine its true state.
+        * This state is only valid during yaffs_Scan.
+        * NB We tolerate empty because the pre-scanner might be incapable of deciding
+        * However, if this state is returned on a YAFFS2 device, then we expect a sequence number
+        */
+
+       YAFFS_BLOCK_STATE_EMPTY,
+       /* This block is empty */
+
+       YAFFS_BLOCK_STATE_ALLOCATING,
+       /* This block is partially allocated. 
+        * At least one page holds valid data.
+        * This is the one currently being used for page
+        * allocation. Should never be more than one of these
+        */
+
+       YAFFS_BLOCK_STATE_FULL, 
+       /* All the pages in this block have been allocated.
+        */
+
+       YAFFS_BLOCK_STATE_DIRTY,
+       /* All pages have been allocated and deleted. 
+        * Erase me, reuse me.
+        */
+
+       YAFFS_BLOCK_STATE_CHECKPOINT,   
+       /* This block is assigned to holding checkpoint data.
+        */
+
+       YAFFS_BLOCK_STATE_COLLECTING,   
+       /* This block is being garbage collected */
+
+       YAFFS_BLOCK_STATE_DEAD  
+       /* This block has failed and is not in use */
+} yaffs_BlockState;
+
+#define        YAFFS_NUMBER_OF_BLOCK_STATES (YAFFS_BLOCK_STATE_DEAD + 1)
+
+
+typedef struct {
+
+       int softDeletions:10;   /* number of soft deleted pages */
+       int pagesInUse:10;      /* number of pages in use */
+       yaffs_BlockState blockState:4;  /* One of the above block states */
+       __u32 needsRetiring:1;  /* Data has failed on this block, need to get valid data off */
+                               /* and retire the block. */
+       __u32 skipErasedCheck: 1; /* If this is set we can skip the erased check on this block */
+       __u32 gcPrioritise: 1;  /* An ECC check or blank check has failed on this block. 
+                                  It should be prioritised for GC */
+        __u32 chunkErrorStrikes:3; /* How many times we've had ecc etc failures on this block and tried to reuse it */
+
+#ifdef CONFIG_YAFFS_YAFFS2
+       __u32 hasShrinkHeader:1; /* This block has at least one shrink object header */
+       __u32 sequenceNumber;    /* block sequence number for yaffs2 */
+#endif
+
+} yaffs_BlockInfo;
+
+/* -------------------------- Object structure -------------------------------*/
+/* This is the object structure as stored on NAND */
+
+typedef struct {
+       yaffs_ObjectType type;
+
+       /* Apply to everything  */
+       int parentObjectId;
+       __u16 sum__NoLongerUsed;        /* checksum of name. No longer used */
+       YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];
+
+       /* Thes following apply to directories, files, symlinks - not hard links */
+       __u32 yst_mode;         /* protection */
+
+#ifdef CONFIG_YAFFS_WINCE
+       __u32 notForWinCE[5];
+#else
+       __u32 yst_uid;
+       __u32 yst_gid;
+       __u32 yst_atime;
+       __u32 yst_mtime;
+       __u32 yst_ctime;
+#endif
+
+       /* File size  applies to files only */
+       int fileSize;
+
+       /* Equivalent object id applies to hard links only. */
+       int equivalentObjectId;
+
+       /* Alias is for symlinks only. */
+       YCHAR alias[YAFFS_MAX_ALIAS_LENGTH + 1];
+
+       __u32 yst_rdev;         /* device stuff for block and char devices (major/min) */
+
+#ifdef CONFIG_YAFFS_WINCE
+       __u32 win_ctime[2];
+       __u32 win_atime[2];
+       __u32 win_mtime[2];
+       __u32 roomToGrow[4];
+#else
+       __u32 roomToGrow[10];
+#endif
+
+       int shadowsObject;      /* This object header shadows the specified object if > 0 */
+
+       /* isShrink applies to object headers written when we shrink the file (ie resize) */
+       __u32 isShrink;
+
+} yaffs_ObjectHeader;
+
+/*--------------------------- Tnode -------------------------- */
+
+union yaffs_Tnode_union {
+#ifdef CONFIG_YAFFS_TNODE_LIST_DEBUG
+       union yaffs_Tnode_union *internal[YAFFS_NTNODES_INTERNAL + 1];
+#else
+       union yaffs_Tnode_union *internal[YAFFS_NTNODES_INTERNAL];
+#endif
+/*     __u16 level0[YAFFS_NTNODES_LEVEL0]; */
+
+};
+
+typedef union yaffs_Tnode_union yaffs_Tnode;
+
+struct yaffs_TnodeList_struct {
+       struct yaffs_TnodeList_struct *next;
+       yaffs_Tnode *tnodes;
+};
+
+typedef struct yaffs_TnodeList_struct yaffs_TnodeList;
+
+/*------------------------  Object -----------------------------*/
+/* An object can be one of:
+ * - a directory (no data, has children links
+ * - a regular file (data.... not prunes :->).
+ * - a symlink [symbolic link] (the alias).
+ * - a hard link
+ */
+
+typedef struct {
+       __u32 fileSize;
+       __u32 scannedFileSize;
+       __u32 shrinkSize;
+       int topLevel;
+       yaffs_Tnode *top;
+} yaffs_FileStructure;
+
+typedef struct {
+       struct list_head children;      /* list of child links */
+} yaffs_DirectoryStructure;
+
+typedef struct {
+       YCHAR *alias;
+} yaffs_SymLinkStructure;
+
+typedef struct {
+       struct yaffs_ObjectStruct *equivalentObject;
+       __u32 equivalentObjectId;
+} yaffs_HardLinkStructure;
+
+typedef union {
+       yaffs_FileStructure fileVariant;
+       yaffs_DirectoryStructure directoryVariant;
+       yaffs_SymLinkStructure symLinkVariant;
+       yaffs_HardLinkStructure hardLinkVariant;
+} yaffs_ObjectVariant;
+
+struct yaffs_ObjectStruct {
+       __u8 deleted:1;         /* This should only apply to unlinked files. */
+       __u8 softDeleted:1;     /* it has also been soft deleted */
+       __u8 unlinked:1;        /* An unlinked file. The file should be in the unlinked directory.*/
+       __u8 fake:1;            /* A fake object has no presence on NAND. */
+       __u8 renameAllowed:1;   /* Some objects are not allowed to be renamed. */
+       __u8 unlinkAllowed:1;
+       __u8 dirty:1;           /* the object needs to be written to flash */
+       __u8 valid:1;           /* When the file system is being loaded up, this 
+                                * object might be created before the data
+                                * is available (ie. file data records appear before the header).
+                                */
+       __u8 lazyLoaded:1;      /* This object has been lazy loaded and is missing some detail */
+
+       __u8 deferedFree:1;     /* For Linux kernel. Object is removed from NAND, but is
+                                * still in the inode cache. Free of object is defered.
+                                * until the inode is released.
+                                */
+
+       __u8 serial;            /* serial number of chunk in NAND. Cached here */
+       __u16 sum;              /* sum of the name to speed searching */
+
+       struct yaffs_DeviceStruct *myDev;       /* The device I'm on */
+
+       struct list_head hashLink;      /* list of objects in this hash bucket */
+
+       struct list_head hardLinks;     /* all the equivalent hard linked objects */
+
+       /* directory structure stuff */
+       /* also used for linking up the free list */
+       struct yaffs_ObjectStruct *parent; 
+       struct list_head siblings;
+
+       /* Where's my object header in NAND? */
+       int chunkId;            
+
+       int nDataChunks;        /* Number of data chunks attached to the file. */
+
+       __u32 objectId;         /* the object id value */
+
+       __u32 yst_mode;
+
+#ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
+       YCHAR shortName[YAFFS_SHORT_NAME_LENGTH + 1];
+#endif
+
+#ifndef __KERNEL__
+       __u32 inUse;
+#endif
+
+#ifdef CONFIG_YAFFS_WINCE
+       __u32 win_ctime[2];
+       __u32 win_mtime[2];
+       __u32 win_atime[2];
+#else
+       __u32 yst_uid;
+       __u32 yst_gid;
+       __u32 yst_atime;
+       __u32 yst_mtime;
+       __u32 yst_ctime;
+#endif
+
+       __u32 yst_rdev;
+
+#ifdef __KERNEL__
+       struct inode *myInode;
+
+#endif
+
+       yaffs_ObjectType variantType;
+
+       yaffs_ObjectVariant variant;
+
+};
+
+typedef struct yaffs_ObjectStruct yaffs_Object;
+
+struct yaffs_ObjectList_struct {
+       yaffs_Object *objects;
+       struct yaffs_ObjectList_struct *next;
+};
+
+typedef struct yaffs_ObjectList_struct yaffs_ObjectList;
+
+typedef struct {
+       struct list_head list;
+       int count;
+} yaffs_ObjectBucket;
+
+
+/* yaffs_CheckpointObject holds the definition of an object as dumped 
+ * by checkpointing.
+ */
+
+typedef struct {
+        int structType;
+       __u32 objectId;         
+       __u32 parentId;
+       int chunkId;
+                       
+       yaffs_ObjectType variantType:3;
+       __u8 deleted:1;         
+       __u8 softDeleted:1;     
+       __u8 unlinked:1;        
+       __u8 fake:1;            
+       __u8 renameAllowed:1;
+       __u8 unlinkAllowed:1;
+       __u8 serial;            
+       
+       int nDataChunks;        
+       __u32 fileSizeOrEquivalentObjectId;
+
+}yaffs_CheckpointObject;
+
+/*--------------------- Temporary buffers ----------------
+ *
+ * These are chunk-sized working buffers. Each device has a few
+ */
+
+typedef struct {
+       __u8 *buffer;
+       int line;       /* track from whence this buffer was allocated */
+       int maxLine;
+} yaffs_TempBuffer;
+
+/*----------------- Device ---------------------------------*/
+
+struct yaffs_DeviceStruct {
+       struct list_head devList;
+       const char *name;
+
+       /* Entry parameters set up way early. Yaffs sets up the rest.*/
+       int nDataBytesPerChunk; /* Should be a power of 2 >= 512 */
+       int nChunksPerBlock;    /* does not need to be a power of 2 */
+       int nBytesPerSpare;     /* spare area size */
+       int startBlock;         /* Start block we're allowed to use */
+       int endBlock;           /* End block we're allowed to use */
+       int nReservedBlocks;    /* We want this tuneable so that we can reduce */
+                               /* reserved blocks on NOR and RAM. */
+       
+       
+       /* Stuff used by the shared space checkpointing mechanism */
+       /* If this value is zero, then this mechanism is disabled */
+       
+       int nCheckpointReservedBlocks; /* Blocks to reserve for checkpoint data */
+
+       
+
+
+       int nShortOpCaches;     /* If <= 0, then short op caching is disabled, else
+                                * the number of short op caches (don't use too many)
+                                */
+
+       int useHeaderFileSize;  /* Flag to determine if we should use file sizes from the header */
+
+       int useNANDECC;         /* Flag to decide whether or not to use NANDECC */
+
+       void *genericDevice;    /* Pointer to device context
+                                * On an mtd this holds the mtd pointer.
+                                */
+        void *superBlock;
+        
+       /* NAND access functions (Must be set before calling YAFFS)*/
+
+       int (*writeChunkToNAND) (struct yaffs_DeviceStruct * dev,
+                                int chunkInNAND, const __u8 * data,
+                                const yaffs_Spare * spare);
+       int (*readChunkFromNAND) (struct yaffs_DeviceStruct * dev,
+                                 int chunkInNAND, __u8 * data,
+                                 yaffs_Spare * spare);
+       int (*eraseBlockInNAND) (struct yaffs_DeviceStruct * dev,
+                                int blockInNAND);
+       int (*initialiseNAND) (struct yaffs_DeviceStruct * dev);
+
+#ifdef CONFIG_YAFFS_YAFFS2
+       int (*writeChunkWithTagsToNAND) (struct yaffs_DeviceStruct * dev,
+                                        int chunkInNAND, const __u8 * data,
+                                        const yaffs_ExtendedTags * tags);
+       int (*readChunkWithTagsFromNAND) (struct yaffs_DeviceStruct * dev,
+                                         int chunkInNAND, __u8 * data,
+                                         yaffs_ExtendedTags * tags);
+       int (*markNANDBlockBad) (struct yaffs_DeviceStruct * dev, int blockNo);
+       int (*queryNANDBlock) (struct yaffs_DeviceStruct * dev, int blockNo,
+                              yaffs_BlockState * state, int *sequenceNumber);
+#endif
+
+       int isYaffs2;
+       
+       /* The removeObjectCallback function must be supplied by OS flavours that 
+        * need it. The Linux kernel does not use this, but yaffs direct does use
+        * it to implement the faster readdir
+        */
+       void (*removeObjectCallback)(struct yaffs_ObjectStruct *obj);
+       
+       /* Callback to mark the superblock dirsty */
+       void (*markSuperBlockDirty)(void * superblock);
+       
+       int wideTnodesDisabled; /* Set to disable wide tnodes */
+       
+
+       /* End of stuff that must be set before initialisation. */
+       
+       /* Checkpoint control. Can be set before or after initialisation */
+       __u8 skipCheckpointRead;
+       __u8 skipCheckpointWrite;
+
+       /* Runtime parameters. Set up by YAFFS. */
+
+       __u16 chunkGroupBits;   /* 0 for devices <= 32MB. else log2(nchunks) - 16 */
+       __u16 chunkGroupSize;   /* == 2^^chunkGroupBits */
+       
+       /* Stuff to support wide tnodes */
+       __u32 tnodeWidth;
+       __u32 tnodeMask;
+       
+       /* Stuff to support various file offses to chunk/offset translations */
+       /* "Crumbs" for nDataBytesPerChunk not being a power of 2 */
+       __u32 crumbMask;
+       __u32 crumbShift;
+       __u32 crumbsPerChunk;
+       
+       /* Straight shifting for nDataBytesPerChunk being a power of 2 */
+       __u32 chunkShift;
+       __u32 chunkMask;
+       
+
+#ifdef __KERNEL__
+
+       struct semaphore sem;   /* Semaphore for waiting on erasure.*/
+       struct semaphore grossLock;     /* Gross locking semaphore */
+       __u8 *spareBuffer;      /* For mtdif2 use. Don't know the size of the buffer 
+                                * at compile time so we have to allocate it.
+                                */
+       void (*putSuperFunc) (struct super_block * sb);
+#endif
+
+       int isMounted;
+       
+       int isCheckpointed;
+
+
+       /* Stuff to support block offsetting to support start block zero */
+       int internalStartBlock;
+       int internalEndBlock;
+       int blockOffset;
+       int chunkOffset;
+       
+
+       /* Runtime checkpointing stuff */
+       int checkpointPageSequence;   /* running sequence number of checkpoint pages */
+       int checkpointByteCount;
+       int checkpointByteOffset;
+       __u8 *checkpointBuffer;
+       int checkpointOpenForWrite;
+       int blocksInCheckpoint;
+       int checkpointCurrentChunk;
+       int checkpointCurrentBlock;
+       int checkpointNextBlock;
+       int *checkpointBlockList;
+       int checkpointMaxBlocks;
+       __u32 checkpointSum;
+       __u32 checkpointXor;
+       
+       /* Block Info */
+       yaffs_BlockInfo *blockInfo;
+       __u8 *chunkBits;        /* bitmap of chunks in use */
+       unsigned blockInfoAlt:1;        /* was allocated using alternative strategy */
+       unsigned chunkBitsAlt:1;        /* was allocated using alternative strategy */
+       int chunkBitmapStride;  /* Number of bytes of chunkBits per block. 
+                                * Must be consistent with nChunksPerBlock.
+                                */
+
+       int nErasedBlocks;
+       int allocationBlock;    /* Current block being allocated off */
+       __u32 allocationPage;
+       int allocationBlockFinder;      /* Used to search for next allocation block */
+
+       /* Runtime state */
+       int nTnodesCreated;
+       yaffs_Tnode *freeTnodes;
+       int nFreeTnodes;
+       yaffs_TnodeList *allocatedTnodeList;
+
+       int isDoingGC;
+
+       int nObjectsCreated;
+       yaffs_Object *freeObjects;
+       int nFreeObjects;
+
+       yaffs_ObjectList *allocatedObjectList;
+
+       yaffs_ObjectBucket objectBucket[YAFFS_NOBJECT_BUCKETS];
+
+       int nFreeChunks;
+
+       int currentDirtyChecker;        /* Used to find current dirtiest block */
+
+       __u32 *gcCleanupList;   /* objects to delete at the end of a GC. */
+       int nonAggressiveSkip;  /* GC state/mode */
+
+       /* Statistcs */
+       int nPageWrites;
+       int nPageReads;
+       int nBlockErasures;
+       int nErasureFailures;
+       int nGCCopies;
+       int garbageCollections;
+       int passiveGarbageCollections;
+       int nRetriedWrites;
+       int nRetiredBlocks;
+       int eccFixed;
+       int eccUnfixed;
+       int tagsEccFixed;
+       int tagsEccUnfixed;
+       int nDeletions;
+       int nUnmarkedDeletions;
+       
+       int hasPendingPrioritisedGCs; /* We think this device might have pending prioritised gcs */
+
+       /* Special directories */
+       yaffs_Object *rootDir;
+       yaffs_Object *lostNFoundDir;
+
+       /* Buffer areas for storing data to recover from write failures TODO
+        *      __u8            bufferedData[YAFFS_CHUNKS_PER_BLOCK][YAFFS_BYTES_PER_CHUNK];
+        *      yaffs_Spare bufferedSpare[YAFFS_CHUNKS_PER_BLOCK];
+        */
+       
+       int bufferedBlock;      /* Which block is buffered here? */
+       int doingBufferedBlockRewrite;
+
+       yaffs_ChunkCache *srCache;
+       int srLastUse;
+
+       int cacheHits;
+
+       /* Stuff for background deletion and unlinked files.*/
+       yaffs_Object *unlinkedDir;      /* Directory where unlinked and deleted files live. */
+       yaffs_Object *deletedDir;       /* Directory where deleted objects are sent to disappear. */
+       yaffs_Object *unlinkedDeletion; /* Current file being background deleted.*/
+       int nDeletedFiles;              /* Count of files awaiting deletion;*/
+       int nUnlinkedFiles;             /* Count of unlinked files. */
+       int nBackgroundDeletions;       /* Count of background deletions. */
+
+
+       yaffs_TempBuffer tempBuffer[YAFFS_N_TEMP_BUFFERS];
+       int maxTemp;
+       int unmanagedTempAllocations;
+       int unmanagedTempDeallocations;
+
+       /* yaffs2 runtime stuff */
+       unsigned sequenceNumber;        /* Sequence number of currently allocating block */
+       unsigned oldestDirtySequence;
+
+};
+
+typedef struct yaffs_DeviceStruct yaffs_Device;
+
+/* The static layout of bllock usage etc is stored in the super block header */
+typedef struct {
+        int StructType;
+       int version;
+       int checkpointStartBlock;
+       int checkpointEndBlock;
+       int startBlock;
+       int endBlock;
+       int rfu[100];
+} yaffs_SuperBlockHeader;
+       
+/* The CheckpointDevice structure holds the device information that changes at runtime and
+ * must be preserved over unmount/mount cycles.
+ */
+typedef struct {
+        int structType;
+       int nErasedBlocks;
+       int allocationBlock;    /* Current block being allocated off */
+       __u32 allocationPage;
+       int nFreeChunks;
+
+       int nDeletedFiles;              /* Count of files awaiting deletion;*/
+       int nUnlinkedFiles;             /* Count of unlinked files. */
+       int nBackgroundDeletions;       /* Count of background deletions. */
+
+       /* yaffs2 runtime stuff */
+       unsigned sequenceNumber;        /* Sequence number of currently allocating block */
+       unsigned oldestDirtySequence;
+
+} yaffs_CheckpointDevice;
+
+
+typedef struct {
+    int structType;
+    __u32 magic;
+    __u32 version;
+    __u32 head;
+} yaffs_CheckpointValidity;
+
+/* Function to manipulate block info */
+static Y_INLINE yaffs_BlockInfo *yaffs_GetBlockInfo(yaffs_Device * dev, int blk)
+{
+       if (blk < dev->internalStartBlock || blk > dev->internalEndBlock) {
+               T(YAFFS_TRACE_ERROR,
+                 (TSTR
+                  ("**>> yaffs: getBlockInfo block %d is not valid" TENDSTR),
+                  blk));
+               YBUG();
+       }
+       return &dev->blockInfo[blk - dev->internalStartBlock];
+}
+
+/*----------------------- YAFFS Functions -----------------------*/
+
+int yaffs_GutsInitialise(yaffs_Device * dev);
+void yaffs_Deinitialise(yaffs_Device * dev);
+
+int yaffs_GetNumberOfFreeChunks(yaffs_Device * dev);
+
+int yaffs_RenameObject(yaffs_Object * oldDir, const YCHAR * oldName,
+                      yaffs_Object * newDir, const YCHAR * newName);
+
+int yaffs_Unlink(yaffs_Object * dir, const YCHAR * name);
+int yaffs_DeleteFile(yaffs_Object * obj);
+
+int yaffs_GetObjectName(yaffs_Object * obj, YCHAR * name, int buffSize);
+int yaffs_GetObjectFileLength(yaffs_Object * obj);
+int yaffs_GetObjectInode(yaffs_Object * obj);
+unsigned yaffs_GetObjectType(yaffs_Object * obj);
+int yaffs_GetObjectLinkCount(yaffs_Object * obj);
+
+int yaffs_SetAttributes(yaffs_Object * obj, struct iattr *attr);
+int yaffs_GetAttributes(yaffs_Object * obj, struct iattr *attr);
+
+/* File operations */
+int yaffs_ReadDataFromFile(yaffs_Object * obj, __u8 * buffer, loff_t offset,
+                          int nBytes);
+int yaffs_WriteDataToFile(yaffs_Object * obj, const __u8 * buffer, loff_t offset,
+                         int nBytes, int writeThrough);
+int yaffs_ResizeFile(yaffs_Object * obj, loff_t newSize);
+
+yaffs_Object *yaffs_MknodFile(yaffs_Object * parent, const YCHAR * name,
+                             __u32 mode, __u32 uid, __u32 gid);
+int yaffs_FlushFile(yaffs_Object * obj, int updateTime);
+
+/* Flushing and checkpointing */
+void yaffs_FlushEntireDeviceCache(yaffs_Device *dev);
+
+int yaffs_CheckpointSave(yaffs_Device *dev);
+int yaffs_CheckpointRestore(yaffs_Device *dev);
+
+/* Directory operations */
+yaffs_Object *yaffs_MknodDirectory(yaffs_Object * parent, const YCHAR * name,
+                                  __u32 mode, __u32 uid, __u32 gid);
+yaffs_Object *yaffs_FindObjectByName(yaffs_Object * theDir, const YCHAR * name);
+int yaffs_ApplyToDirectoryChildren(yaffs_Object * theDir,
+                                  int (*fn) (yaffs_Object *));
+
+yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device * dev, __u32 number);
+
+/* Link operations */
+yaffs_Object *yaffs_Link(yaffs_Object * parent, const YCHAR * name,
+                        yaffs_Object * equivalentObject);
+
+yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object * obj);
+
+/* Symlink operations */
+yaffs_Object *yaffs_MknodSymLink(yaffs_Object * parent, const YCHAR * name,
+                                __u32 mode, __u32 uid, __u32 gid,
+                                const YCHAR * alias);
+YCHAR *yaffs_GetSymlinkAlias(yaffs_Object * obj);
+
+/* Special inodes (fifos, sockets and devices) */
+yaffs_Object *yaffs_MknodSpecial(yaffs_Object * parent, const YCHAR * name,
+                                __u32 mode, __u32 uid, __u32 gid, __u32 rdev);
+
+/* Special directories */
+yaffs_Object *yaffs_Root(yaffs_Device * dev);
+yaffs_Object *yaffs_LostNFound(yaffs_Device * dev);
+
+#ifdef CONFIG_YAFFS_WINCE
+/* CONFIG_YAFFS_WINCE special stuff */
+void yfsd_WinFileTimeNow(__u32 target[2]);
+#endif
+
+#ifdef __KERNEL__
+
+void yaffs_HandleDeferedFree(yaffs_Object * obj);
+#endif
+
+/* Debug dump  */
+int yaffs_DumpObject(yaffs_Object * obj);
+
+void yaffs_GutsTest(yaffs_Device * dev);
+
+/* A few useful functions */
+void yaffs_InitialiseTags(yaffs_ExtendedTags * tags);
+void yaffs_DeleteChunk(yaffs_Device * dev, int chunkId, int markNAND, int lyn);
+int yaffs_CheckFF(__u8 * buffer, int nBytes);
+void yaffs_HandleChunkError(yaffs_Device *dev, yaffs_BlockInfo *bi);
+
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_mtdif.c linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_mtdif.c      1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif.c  2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,241 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+const char *yaffs_mtdif_c_version =
+    "$Id: yaffs_mtdif.c,v 1.19 2007-02-14 01:09:06 wookey Exp $";
+
+#include "yportenv.h"
+
+
+#include "yaffs_mtdif.h"
+
+#include "linux/mtd/mtd.h"
+#include "linux/types.h"
+#include "linux/time.h"
+#include "linux/mtd/nand.h"
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18))
+static struct nand_oobinfo yaffs_oobinfo = {
+       .useecc = 1,
+       .eccbytes = 6,
+       .eccpos = {8, 9, 10, 13, 14, 15}
+};
+
+static struct nand_oobinfo yaffs_noeccinfo = {
+       .useecc = 0,
+};
+#endif
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+static inline void translate_spare2oob(const yaffs_Spare *spare, __u8 *oob)
+{
+       oob[0] = spare->tagByte0;
+       oob[1] = spare->tagByte1;
+       oob[2] = spare->tagByte2;
+       oob[3] = spare->tagByte3;
+       oob[4] = spare->tagByte4;
+       oob[5] = spare->tagByte5 & 0x3f;
+       oob[5] |= spare->blockStatus == 'Y' ? 0: 0x80;
+       oob[5] |= spare->pageStatus == 0 ? 0: 0x40;
+       oob[6] = spare->tagByte6;
+       oob[7] = spare->tagByte7;
+}
+
+static inline void translate_oob2spare(yaffs_Spare *spare, __u8 *oob)
+{
+       struct yaffs_NANDSpare *nspare = (struct yaffs_NANDSpare *)spare;
+       spare->tagByte0 = oob[0];
+       spare->tagByte1 = oob[1];
+       spare->tagByte2 = oob[2];
+       spare->tagByte3 = oob[3];
+       spare->tagByte4 = oob[4];
+       spare->tagByte5 = oob[5] == 0xff ? 0xff : oob[5] & 0x3f;
+       spare->blockStatus = oob[5] & 0x80 ? 0xff : 'Y';
+       spare->pageStatus = oob[5] & 0x40 ? 0xff : 0;
+       spare->ecc1[0] = spare->ecc1[1] = spare->ecc1[2] = 0xff;
+       spare->tagByte6 = oob[6];
+       spare->tagByte7 = oob[7];
+       spare->ecc2[0] = spare->ecc2[1] = spare->ecc2[2] = 0xff;
+
+       nspare->eccres1 = nspare->eccres2 = 0; /* FIXME */
+}
+#endif
+
+int nandmtd_WriteChunkToNAND(yaffs_Device * dev, int chunkInNAND,
+                            const __u8 * data, const yaffs_Spare * spare)
+{
+       struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+       struct mtd_oob_ops ops;
+#endif
+       size_t dummy;
+       int retval = 0;
+
+       loff_t addr = ((loff_t) chunkInNAND) * dev->nDataBytesPerChunk;
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+       __u8 spareAsBytes[8]; /* OOB */
+
+       if (data && !spare)
+               retval = mtd->write(mtd, addr, dev->nDataBytesPerChunk,
+                               &dummy, data);
+       else if (spare) {
+               if (dev->useNANDECC) {
+                       translate_spare2oob(spare, spareAsBytes);
+                       ops.mode = MTD_OOB_AUTO;
+                       ops.ooblen = 8; /* temp hack */
+               } else {
+                       ops.mode = MTD_OOB_RAW;
+                       ops.ooblen = YAFFS_BYTES_PER_SPARE;
+               }
+               ops.len = data ? dev->nDataBytesPerChunk : ops.ooblen;
+               ops.datbuf = (u8 *)data;
+               ops.ooboffs = 0;
+               ops.oobbuf = spareAsBytes;
+               retval = mtd->write_oob(mtd, addr, &ops);
+       }
+#else
+       __u8 *spareAsBytes = (__u8 *) spare;
+
+       if (data && spare) {
+               if (dev->useNANDECC)
+                       retval =
+                           mtd->write_ecc(mtd, addr, dev->nDataBytesPerChunk,
+                                          &dummy, data, spareAsBytes,
+                                          &yaffs_oobinfo);
+               else
+                       retval =
+                           mtd->write_ecc(mtd, addr, dev->nDataBytesPerChunk,
+                                          &dummy, data, spareAsBytes,
+                                          &yaffs_noeccinfo);
+       } else {
+               if (data)
+                       retval =
+                           mtd->write(mtd, addr, dev->nDataBytesPerChunk, &dummy,
+                                      data);
+               if (spare)
+                       retval =
+                           mtd->write_oob(mtd, addr, YAFFS_BYTES_PER_SPARE,
+                                          &dummy, spareAsBytes);
+       }
+#endif
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
+int nandmtd_ReadChunkFromNAND(yaffs_Device * dev, int chunkInNAND, __u8 * data,
+                             yaffs_Spare * spare)
+{
+       struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+       struct mtd_oob_ops ops;
+#endif
+       size_t dummy;
+       int retval = 0;
+
+       loff_t addr = ((loff_t) chunkInNAND) * dev->nDataBytesPerChunk;
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+       __u8 spareAsBytes[8]; /* OOB */
+
+       if (data && !spare)
+               retval = mtd->read(mtd, addr, dev->nDataBytesPerChunk,
+                               &dummy, data);
+       else if (spare) {
+               if (dev->useNANDECC) {
+                       ops.mode = MTD_OOB_AUTO;
+                       ops.ooblen = 8; /* temp hack */
+               } else {
+                       ops.mode = MTD_OOB_RAW;
+                       ops.ooblen = YAFFS_BYTES_PER_SPARE;
+               }
+               ops.len = data ? dev->nDataBytesPerChunk : ops.ooblen;
+               ops.datbuf = data;
+               ops.ooboffs = 0;
+               ops.oobbuf = spareAsBytes;
+               retval = mtd->read_oob(mtd, addr, &ops);
+               if (dev->useNANDECC)
+                       translate_oob2spare(spare, spareAsBytes);
+       }
+#else
+       __u8 *spareAsBytes = (__u8 *) spare;
+
+       if (data && spare) {
+               if (dev->useNANDECC) {  
+                       /* Careful, this call adds 2 ints */
+                       /* to the end of the spare data.  Calling function */
+                       /* should allocate enough memory for spare, */
+                       /* i.e. [YAFFS_BYTES_PER_SPARE+2*sizeof(int)]. */
+                       retval =
+                           mtd->read_ecc(mtd, addr, dev->nDataBytesPerChunk,
+                                         &dummy, data, spareAsBytes,
+                                         &yaffs_oobinfo);
+               } else {
+                       retval =
+                           mtd->read_ecc(mtd, addr, dev->nDataBytesPerChunk,
+                                         &dummy, data, spareAsBytes,
+                                         &yaffs_noeccinfo);
+               }
+       } else {
+               if (data)
+                       retval =
+                           mtd->read(mtd, addr, dev->nDataBytesPerChunk, &dummy,
+                                     data);
+               if (spare)
+                       retval =
+                           mtd->read_oob(mtd, addr, YAFFS_BYTES_PER_SPARE,
+                                         &dummy, spareAsBytes);
+       }
+#endif
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
+int nandmtd_EraseBlockInNAND(yaffs_Device * dev, int blockNumber)
+{
+       struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+       __u32 addr =
+           ((loff_t) blockNumber) * dev->nDataBytesPerChunk
+               * dev->nChunksPerBlock;
+       struct erase_info ei;
+       int retval = 0;
+
+       ei.mtd = mtd;
+       ei.addr = addr;
+       ei.len = dev->nDataBytesPerChunk * dev->nChunksPerBlock;
+       ei.time = 1000;
+       ei.retries = 2;
+       ei.callback = NULL;
+       ei.priv = (u_long) dev;
+
+       /* Todo finish off the ei if required */
+
+       sema_init(&dev->sem, 0);
+
+       retval = mtd->erase(mtd, &ei);
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
+int nandmtd_InitialiseNAND(yaffs_Device * dev)
+{
+       return YAFFS_OK;
+}
+
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_mtdif.h linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_mtdif.h      1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif.h  2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,27 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_MTDIF_H__
+#define __YAFFS_MTDIF_H__
+
+#include "yaffs_guts.h"
+
+int nandmtd_WriteChunkToNAND(yaffs_Device * dev, int chunkInNAND,
+                            const __u8 * data, const yaffs_Spare * spare);
+int nandmtd_ReadChunkFromNAND(yaffs_Device * dev, int chunkInNAND, __u8 * data,
+                             yaffs_Spare * spare);
+int nandmtd_EraseBlockInNAND(yaffs_Device * dev, int blockNumber);
+int nandmtd_InitialiseNAND(yaffs_Device * dev);
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_mtdif1-compat.c linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif1-compat.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_mtdif1-compat.c      1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif1-compat.c  2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,434 @@
+From ian@brightstareng.com Fri May 18 15:06:49 2007
+From ian@brightstareng.com Fri May 18 15:08:21 2007
+Received: from 206.173.66.57.ptr.us.xo.net ([206.173.66.57] helo=zebra.brightstareng.com)
+       by apollo.linkchoose.co.uk with esmtp (Exim 4.60)
+       (envelope-from <ian@brightstareng.com>)
+       id 1Hp380-00011e-T6
+       for david.goodenough@linkchoose.co.uk; Fri, 18 May 2007 15:08:21 +0100
+Received: from localhost (localhost.localdomain [127.0.0.1])
+       by zebra.brightstareng.com (Postfix) with ESMTP
+       id 4819F28C004; Fri, 18 May 2007 10:07:49 -0400 (EDT)
+Received: from zebra.brightstareng.com ([127.0.0.1])
+ by localhost (zebra [127.0.0.1]) (amavisd-new, port 10024) with ESMTP
+ id 05328-06; Fri, 18 May 2007 10:07:16 -0400 (EDT)
+Received: from pippin (unknown [192.168.1.25])
+       by zebra.brightstareng.com (Postfix) with ESMTP
+       id 8BEF528C1BC; Fri, 18 May 2007 10:06:53 -0400 (EDT)
+From: Ian McDonnell <ian@brightstareng.com>
+To: David Goodenough <david.goodenough@linkchoose.co.uk>
+Subject: Re: something tested this time -- yaffs_mtdif1-compat.c
+Date: Fri, 18 May 2007 10:06:49 -0400
+User-Agent: KMail/1.9.1
+References: <200705142207.06909.ian@brightstareng.com> <200705171131.53536.ian@brightstareng.com> <200705181334.32166.david.goodenough@linkchoose.co.uk>
+In-Reply-To: <200705181334.32166.david.goodenough@linkchoose.co.uk>
+Cc: Andrea Conti <alyf@alyf.net>,
+ Charles Manning <manningc2@actrix.gen.nz>
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+Message-Id: <200705181006.49860.ian@brightstareng.com>
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+--Boundary-00=_5LbTGmt62YoutxM
+Content-Type: text/plain;
+  charset="iso-8859-15"
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+
+David, Andrea,
+
+On Friday 18 May 2007 08:34, you wrote:
+> Yea team.  With this fix in place (I put it in the wrong place
+> at first) I can now mount and ls the Yaffs partition without
+> an error messages!
+
+Good news!
+
+Attached is a newer yaffs_mtdif1.c with a bandaid to help the 
+2.6.18 and 2.6.19 versions of MTD not trip on the oob read.
+See the LINUX_VERSION_CODE conditional in 
+nandmtd1_ReadChunkWithTagsFromNAND.
+
+-imcd
+
+--Boundary-00=_5LbTGmt62YoutxM
+Content-Type: text/x-csrc;
+  charset="iso-8859-15";
+  name="yaffs_mtdif1.c"
+Content-Transfer-Encoding: 7bit
+Content-Disposition: attachment;
+       filename="yaffs_mtdif1.c"
+
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_mtdif1.c  NAND mtd interface functions for small-page NAND.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This module provides the interface between yaffs_nand.c and the
+ * MTD API.  This version is used when the MTD interface supports the
+ * 'mtd_oob_ops' style calls to read_oob and write_oob, circa 2.6.17,
+ * and we have small-page NAND device.
+ *
+ * These functions are invoked via function pointers in yaffs_nand.c.
+ * This replaces functionality provided by functions in yaffs_mtdif.c
+ * and the yaffs_TagsCompatability functions in yaffs_tagscompat.c that are
+ * called in yaffs_mtdif.c when the function pointers are NULL.
+ * We assume the MTD layer is performing ECC (useNANDECC is true).
+ */
+
+#include "yportenv.h"
+#include "yaffs_guts.h"
+#include "yaffs_packedtags1.h"
+#include "yaffs_tagscompat.h"  // for yaffs_CalcTagsECC
+
+#include "linux/kernel.h"
+#include "linux/version.h"
+#include "linux/types.h"
+#include "linux/mtd/mtd.h"
+
+/* Don't compile this module if we don't have MTD's mtd_oob_ops interface */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+
+const char *yaffs_mtdif1_c_version = "$Id: yaffs_mtdif1.c,v 1.3 2007/05/15 20:16:11 ian Exp $";
+
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+# define YTAG1_SIZE 8
+#else
+# define YTAG1_SIZE 9
+#endif
+
+#if 0
+/* Use the following nand_ecclayout with MTD when using
+ * CONFIG_YAFFS_9BYTE_TAGS and the older on-NAND tags layout.
+ * If you have existing Yaffs images and the byte order differs from this,
+ * adjust 'oobfree' to match your existing Yaffs data.
+ *
+ * This nand_ecclayout scatters/gathers to/from the old-yaffs layout with the
+ * pageStatus byte (at NAND spare offset 4) scattered/gathered from/to
+ * the 9th byte.
+ *
+ * Old-style on-NAND format: T0,T1,T2,T3,P,B,T4,T5,E0,E1,E2,T6,T7,E3,E4,E5
+ * We have/need PackedTags1 plus pageStatus: T0,T1,T2,T3,T4,T5,T6,T7,P
+ * where Tn are the tag bytes, En are MTD's ECC bytes, P is the pageStatus
+ * byte and B is the small-page bad-block indicator byte.
+ */
+static struct nand_ecclayout nand_oob_16 = {
+       .eccbytes = 6,
+       .eccpos = { 8, 9, 10, 13, 14, 15 },
+       .oobavail = 9,
+       .oobfree = { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
+};
+#endif
+
+/* Write a chunk (page) of data to NAND.
+ *
+ * Caller always provides ExtendedTags data which are converted to a more
+ * compact (packed) form for storage in NAND.  A mini-ECC runs over the
+ * contents of the tags meta-data; used to valid the tags when read.
+ *
+ *  - Pack ExtendedTags to PackedTags1 form
+ *  - Compute mini-ECC for PackedTags1
+ *  - Write data and packed tags to NAND.
+ *
+ * Note: Due to the use of the PackedTags1 meta-data which does not include
+ * a full sequence number (as found in the larger PackedTags2 form) it is
+ * necessary for Yaffs to re-write a chunk/page (just once) to mark it as
+ * discarded and dirty.  This is not ideal: newer NAND parts are supposed
+ * to be written just once.  When Yaffs performs this operation, this
+ * function is called with a NULL data pointer -- calling MTD write_oob
+ * without data is valid usage (2.6.17).
+ *
+ * Any underlying MTD error results in YAFFS_FAIL.
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_WriteChunkWithTagsToNAND(yaffs_Device *dev,
+       int chunkInNAND, const __u8 * data, const yaffs_ExtendedTags * etags)
+{
+       struct mtd_info * mtd = dev->genericDevice;
+       int chunkBytes = dev->nDataBytesPerChunk;
+       loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
+       struct mtd_oob_ops ops;
+       yaffs_PackedTags1 pt1;
+       int retval;
+
+       /* we assume that PackedTags1 and yaffs_Tags are compatible */
+       compile_time_assertion(sizeof(yaffs_PackedTags1) == 12);
+       compile_time_assertion(sizeof(yaffs_Tags) == 8);
+
+       yaffs_PackTags1(&pt1, etags);
+       yaffs_CalcTagsECC((yaffs_Tags *)&pt1);
+
+       /* When deleting a chunk, the upper layer provides only skeletal
+        * etags, one with chunkDeleted set.  However, we need to update the
+        * tags, not erase them completely.  So we use the NAND write property
+        * that only zeroed-bits stick and set tag bytes to all-ones and
+        * zero just the (not) deleted bit.
+        */
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+       if (etags->chunkDeleted) {
+               memset(&pt1, 0xff, 8);
+               /* clear delete status bit to indicate deleted */
+               pt1.deleted = 0;
+       }
+#else
+       ((__u8 *)&pt1)[8] = 0xff;
+       if (etags->chunkDeleted) {
+               memset(&pt1, 0xff, 8);
+               /* zero pageStatus byte to indicate deleted */
+               ((__u8 *)&pt1)[8] = 0;
+       }
+#endif
+
+       memset(&ops, 0, sizeof(ops));
+       ops.mode = MTD_OOB_AUTO;
+       ops.len = (data) ? chunkBytes : 0;
+       ops.ooblen = YTAG1_SIZE;
+       ops.datbuf = (__u8 *)data;
+       ops.oobbuf = (__u8 *)&pt1;
+
+       retval = mtd->write_oob(mtd, addr, &ops);
+       if (retval) {
+               yaffs_trace(YAFFS_TRACE_MTD,
+                       "write_oob failed, chunk %d, mtd error %d\n",
+                       chunkInNAND, retval);
+       }
+       return retval ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Return with empty ExtendedTags but add eccResult.
+ */
+static int rettags(yaffs_ExtendedTags * etags, int eccResult, int retval)
+{
+       if (etags) {
+               memset(etags, 0, sizeof(*etags));
+               etags->eccResult = eccResult;
+       }
+       return retval;
+}
+
+/* Read a chunk (page) from NAND.
+ *
+ * Caller expects ExtendedTags data to be usable even on error; that is,
+ * all members except eccResult and blockBad are zeroed.
+ *
+ *  - Check ECC results for data (if applicable)
+ *  - Check for blank/erased block (return empty ExtendedTags if blank)
+ *  - Check the PackedTags1 mini-ECC (correct if necessary/possible)
+ *  - Convert PackedTags1 to ExtendedTags
+ *  - Update eccResult and blockBad members to refect state.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_ReadChunkWithTagsFromNAND(yaffs_Device *dev,
+       int chunkInNAND, __u8 * data, yaffs_ExtendedTags * etags)
+{
+       struct mtd_info * mtd = dev->genericDevice;
+       int chunkBytes = dev->nDataBytesPerChunk;
+       loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
+       int eccres = YAFFS_ECC_RESULT_NO_ERROR;
+       struct mtd_oob_ops ops;
+       yaffs_PackedTags1 pt1;
+       int retval;
+       int deleted;
+
+       memset(&ops, 0, sizeof(ops));
+       ops.mode = MTD_OOB_AUTO;
+       ops.len = (data) ? chunkBytes : 0;
+       ops.ooblen = YTAG1_SIZE;
+       ops.datbuf = data;
+       ops.oobbuf = (__u8 *)&pt1;
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20))
+       /* In MTD 2.6.18 to 2.6.19 nand_base.c:nand_do_read_oob() has a bug;
+        * help it out with ops.len = ops.ooblen when ops.datbuf == NULL.
+        */
+       ops.len = (ops.datbuf) ? ops.len : ops.ooblen;
+#endif
+       /* Read page and oob using MTD.
+        * Check status and determine ECC result.
+        */
+       retval = mtd->read_oob(mtd, addr, &ops);
+       if (retval) {
+               yaffs_trace(YAFFS_TRACE_MTD,
+                       "read_oob failed, chunk %d, mtd error %d\n",
+                       chunkInNAND, retval);
+       }
+
+       switch (retval) {
+       case 0:
+               /* no error */
+               break;
+
+       case -EUCLEAN:
+               /* MTD's ECC fixed the data */
+               eccres = YAFFS_ECC_RESULT_FIXED;
+               dev->eccFixed++;
+               break;
+
+       case -EBADMSG:
+               /* MTD's ECC could not fix the data */
+               dev->eccUnfixed++;
+               /* fall into... */
+       default:
+               rettags(etags, YAFFS_ECC_RESULT_UNFIXED, 0);
+               etags->blockBad = (mtd->block_isbad)(mtd, addr);
+               return YAFFS_FAIL;
+       }
+
+       /* Check for a blank/erased chunk.
+        */
+       if (yaffs_CheckFF((__u8 *)&pt1, 8)) {
+               /* when blank, upper layers want eccResult to be <= NO_ERROR */
+               return rettags(etags, YAFFS_ECC_RESULT_NO_ERROR, YAFFS_OK);
+       }
+
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+       /* Read deleted status (bit) then return it to it's non-deleted
+        * state before performing tags mini-ECC check. pt1.deleted is
+        * inverted.
+        */
+       deleted = !pt1.deleted;
+       pt1.deleted = 1;
+#else
+       (void) deleted; /* not used */
+#endif
+
+       /* Check the packed tags mini-ECC and correct if necessary/possible.
+        */
+       retval = yaffs_CheckECCOnTags((yaffs_Tags *)&pt1);
+       switch (retval) {
+       case 0:
+               /* no tags error, use MTD result */
+               break;
+       case 1:
+               /* recovered tags-ECC error */
+               dev->tagsEccFixed++;
+               eccres = YAFFS_ECC_RESULT_FIXED;
+               break;
+       default:
+               /* unrecovered tags-ECC error */
+               dev->tagsEccUnfixed++;
+               return rettags(etags, YAFFS_ECC_RESULT_UNFIXED, YAFFS_FAIL);
+       }
+
+       /* Unpack the tags to extended form and set ECC result.
+        * [set shouldBeFF just to keep yaffs_UnpackTags1 happy]
+        */
+       pt1.shouldBeFF = 0xFFFFFFFF;
+       yaffs_UnpackTags1(etags, &pt1);
+       etags->eccResult = eccres;
+
+       /* Set deleted state.
+        */
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+       etags->chunkDeleted = deleted;
+#else
+       etags->chunkDeleted = (yaffs_CountBits(((__u8 *)&pt1)[8]) < 7);
+#endif
+       return YAFFS_OK;
+}
+
+/* Mark a block bad.
+ *
+ * This is a persistant state.
+ * Use of this function should be rare.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
+{
+       struct mtd_info * mtd = dev->genericDevice;
+       int blocksize = dev->nChunksPerBlock * dev->nDataBytesPerChunk;
+       int retval;
+
+       yaffs_trace(YAFFS_TRACE_BAD_BLOCKS, "marking block %d bad", blockNo);
+
+       retval = mtd->block_markbad(mtd, (loff_t)blocksize * blockNo);
+       return (retval) ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Check any MTD prerequists.
+ * 
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+static int nandmtd1_TestPrerequists(struct mtd_info * mtd)
+{
+       /* 2.6.18 has mtd->ecclayout->oobavail */
+       /* 2.6.21 has mtd->ecclayout->oobavail and mtd->oobavail */
+       int oobavail = mtd->ecclayout->oobavail;
+
+       if (oobavail < YTAG1_SIZE) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "mtd device has only %d bytes for tags, need %d",
+                       oobavail, YTAG1_SIZE);
+               return YAFFS_FAIL;
+       }
+       return YAFFS_OK;
+}
+
+/* Query for the current state of a specific block.
+ *
+ * Examine the tags of the first chunk of the block and return the state:
+ *  - YAFFS_BLOCK_STATE_DEAD, the block is marked bad
+ *  - YAFFS_BLOCK_STATE_NEEDS_SCANNING, the block is in use
+ *  - YAFFS_BLOCK_STATE_EMPTY, the block is clean
+ *
+ * Always returns YAFFS_OK.
+ */
+int nandmtd1_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo,
+       yaffs_BlockState * pState, int *pSequenceNumber)
+{
+       struct mtd_info * mtd = dev->genericDevice;
+       int chunkNo = blockNo * dev->nChunksPerBlock;
+       yaffs_ExtendedTags etags;
+       int state = YAFFS_BLOCK_STATE_DEAD;
+       int seqnum = 0;
+       int retval;
+
+       /* We don't yet have a good place to test for MTD config prerequists.
+        * Do it here as we are called during the initial scan.
+        */
+       if (nandmtd1_TestPrerequists(mtd) != YAFFS_OK) {
+               return YAFFS_FAIL;
+       }
+
+       retval = nandmtd1_ReadChunkWithTagsFromNAND(dev, chunkNo, NULL, &etags);
+       if (etags.blockBad) {
+               yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+                       "block %d is marked bad", blockNo);
+               state = YAFFS_BLOCK_STATE_DEAD;
+       }
+       else if (etags.chunkUsed) {
+               state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+               seqnum = etags.sequenceNumber;
+       }
+       else {
+               state = YAFFS_BLOCK_STATE_EMPTY;
+       }
+
+       *pState = state;
+       *pSequenceNumber = seqnum;
+
+       /* query always succeeds */
+       return YAFFS_OK;
+}
+
+#endif /*KERNEL_VERSION*/
+
+--Boundary-00=_5LbTGmt62YoutxM--
+
+
+
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_mtdif1.c linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif1.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_mtdif1.c     1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif1.c 2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,363 @@
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_mtdif1.c  NAND mtd interface functions for small-page NAND.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * This module provides the interface between yaffs_nand.c and the
+ * MTD API.  This version is used when the MTD interface supports the
+ * 'mtd_oob_ops' style calls to read_oob and write_oob, circa 2.6.17,
+ * and we have small-page NAND device.
+ *
+ * These functions are invoked via function pointers in yaffs_nand.c.
+ * This replaces functionality provided by functions in yaffs_mtdif.c
+ * and the yaffs_TagsCompatability functions in yaffs_tagscompat.c that are
+ * called in yaffs_mtdif.c when the function pointers are NULL.
+ * We assume the MTD layer is performing ECC (useNANDECC is true).
+ */
+
+#include "yportenv.h"
+#include "yaffs_guts.h"
+#include "yaffs_packedtags1.h"
+#include "yaffs_tagscompat.h"  // for yaffs_CalcTagsECC
+
+#include "linux/kernel.h"
+#include "linux/version.h"
+#include "linux/types.h"
+#include "linux/mtd/mtd.h"
+
+/* Don't compile this module if we don't have MTD's mtd_oob_ops interface */
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+
+const char *yaffs_mtdif1_c_version = "$Id: yaffs_mtdif1.c,v 1.3 2007/05/15 20:16:11 ian Exp $";
+
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+# define YTAG1_SIZE 8
+#else
+# define YTAG1_SIZE 9
+#endif
+
+#if 0
+/* Use the following nand_ecclayout with MTD when using
+ * CONFIG_YAFFS_9BYTE_TAGS and the older on-NAND tags layout.
+ * If you have existing Yaffs images and the byte order differs from this,
+ * adjust 'oobfree' to match your existing Yaffs data.
+ *
+ * This nand_ecclayout scatters/gathers to/from the old-yaffs layout with the
+ * pageStatus byte (at NAND spare offset 4) scattered/gathered from/to
+ * the 9th byte.
+ *
+ * Old-style on-NAND format: T0,T1,T2,T3,P,B,T4,T5,E0,E1,E2,T6,T7,E3,E4,E5
+ * We have/need PackedTags1 plus pageStatus: T0,T1,T2,T3,T4,T5,T6,T7,P
+ * where Tn are the tag bytes, En are MTD's ECC bytes, P is the pageStatus
+ * byte and B is the small-page bad-block indicator byte.
+ */
+static struct nand_ecclayout nand_oob_16 = {
+       .eccbytes = 6,
+       .eccpos = { 8, 9, 10, 13, 14, 15 },
+       .oobavail = 9,
+       .oobfree = { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
+};
+#endif
+
+/* Write a chunk (page) of data to NAND.
+ *
+ * Caller always provides ExtendedTags data which are converted to a more
+ * compact (packed) form for storage in NAND.  A mini-ECC runs over the
+ * contents of the tags meta-data; used to valid the tags when read.
+ *
+ *  - Pack ExtendedTags to PackedTags1 form
+ *  - Compute mini-ECC for PackedTags1
+ *  - Write data and packed tags to NAND.
+ *
+ * Note: Due to the use of the PackedTags1 meta-data which does not include
+ * a full sequence number (as found in the larger PackedTags2 form) it is
+ * necessary for Yaffs to re-write a chunk/page (just once) to mark it as
+ * discarded and dirty.  This is not ideal: newer NAND parts are supposed
+ * to be written just once.  When Yaffs performs this operation, this
+ * function is called with a NULL data pointer -- calling MTD write_oob
+ * without data is valid usage (2.6.17).
+ *
+ * Any underlying MTD error results in YAFFS_FAIL.
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_WriteChunkWithTagsToNAND(yaffs_Device *dev,
+       int chunkInNAND, const __u8 * data, const yaffs_ExtendedTags * etags)
+{
+       struct mtd_info * mtd = dev->genericDevice;
+       int chunkBytes = dev->nDataBytesPerChunk;
+       loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
+       struct mtd_oob_ops ops;
+       yaffs_PackedTags1 pt1;
+       int retval;
+
+       /* we assume that PackedTags1 and yaffs_Tags are compatible */
+       compile_time_assertion(sizeof(yaffs_PackedTags1) == 12);
+       compile_time_assertion(sizeof(yaffs_Tags) == 8);
+
+       dev->nPageWrites++;
+
+       yaffs_PackTags1(&pt1, etags);
+       yaffs_CalcTagsECC((yaffs_Tags *)&pt1);
+
+       /* When deleting a chunk, the upper layer provides only skeletal
+        * etags, one with chunkDeleted set.  However, we need to update the
+        * tags, not erase them completely.  So we use the NAND write property
+        * that only zeroed-bits stick and set tag bytes to all-ones and
+        * zero just the (not) deleted bit.
+        */
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+       if (etags->chunkDeleted) {
+               memset(&pt1, 0xff, 8);
+               /* clear delete status bit to indicate deleted */
+               pt1.deleted = 0;
+       }
+#else
+       ((__u8 *)&pt1)[8] = 0xff;
+       if (etags->chunkDeleted) {
+               memset(&pt1, 0xff, 8);
+               /* zero pageStatus byte to indicate deleted */
+               ((__u8 *)&pt1)[8] = 0;
+       }
+#endif
+
+       memset(&ops, 0, sizeof(ops));
+       ops.mode = MTD_OOB_AUTO;
+       ops.len = (data) ? chunkBytes : 0;
+       ops.ooblen = YTAG1_SIZE;
+       ops.datbuf = (__u8 *)data;
+       ops.oobbuf = (__u8 *)&pt1;
+
+       retval = mtd->write_oob(mtd, addr, &ops);
+       if (retval) {
+               yaffs_trace(YAFFS_TRACE_MTD,
+                       "write_oob failed, chunk %d, mtd error %d\n",
+                       chunkInNAND, retval);
+       }
+       return retval ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Return with empty ExtendedTags but add eccResult.
+ */
+static int rettags(yaffs_ExtendedTags * etags, int eccResult, int retval)
+{
+       if (etags) {
+               memset(etags, 0, sizeof(*etags));
+               etags->eccResult = eccResult;
+       }
+       return retval;
+}
+
+/* Read a chunk (page) from NAND.
+ *
+ * Caller expects ExtendedTags data to be usable even on error; that is,
+ * all members except eccResult and blockBad are zeroed.
+ *
+ *  - Check ECC results for data (if applicable)
+ *  - Check for blank/erased block (return empty ExtendedTags if blank)
+ *  - Check the PackedTags1 mini-ECC (correct if necessary/possible)
+ *  - Convert PackedTags1 to ExtendedTags
+ *  - Update eccResult and blockBad members to refect state.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_ReadChunkWithTagsFromNAND(yaffs_Device *dev,
+       int chunkInNAND, __u8 * data, yaffs_ExtendedTags * etags)
+{
+       struct mtd_info * mtd = dev->genericDevice;
+       int chunkBytes = dev->nDataBytesPerChunk;
+       loff_t addr = ((loff_t)chunkInNAND) * chunkBytes;
+       int eccres = YAFFS_ECC_RESULT_NO_ERROR;
+       struct mtd_oob_ops ops;
+       yaffs_PackedTags1 pt1;
+       int retval;
+       int deleted;
+
+       dev->nPageReads++;
+
+       memset(&ops, 0, sizeof(ops));
+       ops.mode = MTD_OOB_AUTO;
+       ops.len = (data) ? chunkBytes : 0;
+       ops.ooblen = YTAG1_SIZE;
+       ops.datbuf = data;
+       ops.oobbuf = (__u8 *)&pt1;
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20))
+       /* In MTD 2.6.18 to 2.6.19 nand_base.c:nand_do_read_oob() has a bug;
+        * help it out with ops.len = ops.ooblen when ops.datbuf == NULL.
+        */
+       ops.len = (ops.datbuf) ? ops.len : ops.ooblen;
+#endif
+       /* Read page and oob using MTD.
+        * Check status and determine ECC result.
+        */
+       retval = mtd->read_oob(mtd, addr, &ops);
+       if (retval) {
+               yaffs_trace(YAFFS_TRACE_MTD,
+                       "read_oob failed, chunk %d, mtd error %d\n",
+                       chunkInNAND, retval);
+       }
+
+       switch (retval) {
+       case 0:
+               /* no error */
+               break;
+
+       case -EUCLEAN:
+               /* MTD's ECC fixed the data */
+               eccres = YAFFS_ECC_RESULT_FIXED;
+               dev->eccFixed++;
+               break;
+
+       case -EBADMSG:
+               /* MTD's ECC could not fix the data */
+               dev->eccUnfixed++;
+               /* fall into... */
+       default:
+               rettags(etags, YAFFS_ECC_RESULT_UNFIXED, 0);
+               etags->blockBad = (mtd->block_isbad)(mtd, addr);
+               return YAFFS_FAIL;
+       }
+
+       /* Check for a blank/erased chunk.
+        */
+       if (yaffs_CheckFF((__u8 *)&pt1, 8)) {
+               /* when blank, upper layers want eccResult to be <= NO_ERROR */
+               return rettags(etags, YAFFS_ECC_RESULT_NO_ERROR, YAFFS_OK);
+       }
+
+#ifndef CONFIG_YAFFS_9BYTE_TAGS
+       /* Read deleted status (bit) then return it to it's non-deleted
+        * state before performing tags mini-ECC check. pt1.deleted is
+        * inverted.
+        */
+       deleted = !pt1.deleted;
+       pt1.deleted = 1;
+#else
+       deleted = (yaffs_CountBits(((__u8 *)&pt1)[8]) < 7);
+#endif
+
+       /* Check the packed tags mini-ECC and correct if necessary/possible.
+        */
+       retval = yaffs_CheckECCOnTags((yaffs_Tags *)&pt1);
+       switch (retval) {
+       case 0:
+               /* no tags error, use MTD result */
+               break;
+       case 1:
+               /* recovered tags-ECC error */
+               dev->tagsEccFixed++;
+               if (eccres == YAFFS_ECC_RESULT_NO_ERROR)
+                       eccres = YAFFS_ECC_RESULT_FIXED;
+               break;
+       default:
+               /* unrecovered tags-ECC error */
+               dev->tagsEccUnfixed++;
+               return rettags(etags, YAFFS_ECC_RESULT_UNFIXED, YAFFS_FAIL);
+       }
+
+       /* Unpack the tags to extended form and set ECC result.
+        * [set shouldBeFF just to keep yaffs_UnpackTags1 happy]
+        */
+       pt1.shouldBeFF = 0xFFFFFFFF;
+       yaffs_UnpackTags1(etags, &pt1);
+       etags->eccResult = eccres;
+
+       /* Set deleted state */
+       etags->chunkDeleted = deleted;
+       return YAFFS_OK;
+}
+
+/* Mark a block bad.
+ *
+ * This is a persistant state.
+ * Use of this function should be rare.
+ *
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+int nandmtd1_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
+{
+       struct mtd_info * mtd = dev->genericDevice;
+       int blocksize = dev->nChunksPerBlock * dev->nDataBytesPerChunk;
+       int retval;
+
+       yaffs_trace(YAFFS_TRACE_BAD_BLOCKS, "marking block %d bad", blockNo);
+
+       retval = mtd->block_markbad(mtd, (loff_t)blocksize * blockNo);
+       return (retval) ? YAFFS_FAIL : YAFFS_OK;
+}
+
+/* Check any MTD prerequists.
+ * 
+ * Returns YAFFS_OK or YAFFS_FAIL.
+ */
+static int nandmtd1_TestPrerequists(struct mtd_info * mtd)
+{
+       /* 2.6.18 has mtd->ecclayout->oobavail */
+       /* 2.6.21 has mtd->ecclayout->oobavail and mtd->oobavail */
+       int oobavail = mtd->ecclayout->oobavail;
+
+       if (oobavail < YTAG1_SIZE) {
+               yaffs_trace(YAFFS_TRACE_ERROR,
+                       "mtd device has only %d bytes for tags, need %d\n",
+                       oobavail, YTAG1_SIZE);
+               return YAFFS_FAIL;
+       }
+       return YAFFS_OK;
+}
+
+/* Query for the current state of a specific block.
+ *
+ * Examine the tags of the first chunk of the block and return the state:
+ *  - YAFFS_BLOCK_STATE_DEAD, the block is marked bad
+ *  - YAFFS_BLOCK_STATE_NEEDS_SCANNING, the block is in use
+ *  - YAFFS_BLOCK_STATE_EMPTY, the block is clean
+ *
+ * Always returns YAFFS_OK.
+ */
+int nandmtd1_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo,
+       yaffs_BlockState * pState, int *pSequenceNumber)
+{
+       struct mtd_info * mtd = dev->genericDevice;
+       int chunkNo = blockNo * dev->nChunksPerBlock;
+       yaffs_ExtendedTags etags;
+       int state = YAFFS_BLOCK_STATE_DEAD;
+       int seqnum = 0;
+       int retval;
+
+       /* We don't yet have a good place to test for MTD config prerequists.
+        * Do it here as we are called during the initial scan.
+        */
+       if (nandmtd1_TestPrerequists(mtd) != YAFFS_OK) {
+               return YAFFS_FAIL;
+       }
+
+       retval = nandmtd1_ReadChunkWithTagsFromNAND(dev, chunkNo, NULL, &etags);
+       if (etags.blockBad) {
+               yaffs_trace(YAFFS_TRACE_BAD_BLOCKS,
+                       "block %d is marked bad", blockNo);
+               state = YAFFS_BLOCK_STATE_DEAD;
+       }
+       else if (etags.chunkUsed) {
+               state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+               seqnum = etags.sequenceNumber;
+       }
+       else {
+               state = YAFFS_BLOCK_STATE_EMPTY;
+       }
+
+       *pState = state;
+       *pSequenceNumber = seqnum;
+
+       /* query always succeeds */
+       return YAFFS_OK;
+}
+
+#endif /*KERNEL_VERSION*/
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_mtdif1.h linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif1.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_mtdif1.h     1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif1.h 2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,28 @@
+/*
+ * YAFFS: Yet another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_MTDIF1_H__
+#define __YAFFS_MTDIF1_H__
+
+int nandmtd1_WriteChunkWithTagsToNAND(yaffs_Device * dev, int chunkInNAND,
+       const __u8 * data, const yaffs_ExtendedTags * tags);
+
+int nandmtd1_ReadChunkWithTagsFromNAND(yaffs_Device * dev, int chunkInNAND,
+       __u8 * data, yaffs_ExtendedTags * tags);
+
+int nandmtd1_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo);
+
+int nandmtd1_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo,
+       yaffs_BlockState * state, int *sequenceNumber);
+
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_mtdif2.c linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif2.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_mtdif2.c     1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif2.c 2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,232 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/* mtd interface for YAFFS2 */
+
+const char *yaffs_mtdif2_c_version =
+    "$Id: yaffs_mtdif2.c,v 1.17 2007-02-14 01:09:06 wookey Exp $";
+
+#include "yportenv.h"
+
+
+#include "yaffs_mtdif2.h"
+
+#include "linux/mtd/mtd.h"
+#include "linux/types.h"
+#include "linux/time.h"
+
+#include "yaffs_packedtags2.h"
+
+int nandmtd2_WriteChunkWithTagsToNAND(yaffs_Device * dev, int chunkInNAND,
+                                     const __u8 * data,
+                                     const yaffs_ExtendedTags * tags)
+{
+       struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+       struct mtd_oob_ops ops;
+#else
+       size_t dummy;
+#endif
+       int retval = 0;
+
+       loff_t addr = ((loff_t) chunkInNAND) * dev->nDataBytesPerChunk;
+
+       yaffs_PackedTags2 pt;
+
+       T(YAFFS_TRACE_MTD,
+         (TSTR
+          ("nandmtd2_WriteChunkWithTagsToNAND chunk %d data %p tags %p"
+           TENDSTR), chunkInNAND, data, tags));
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+       if (tags)
+               yaffs_PackTags2(&pt, tags);
+       else
+               BUG(); /* both tags and data should always be present */
+
+       if (data) {
+               ops.mode = MTD_OOB_AUTO;
+               ops.ooblen = sizeof(pt);
+               ops.len = dev->nDataBytesPerChunk;
+               ops.ooboffs = 0;
+               ops.datbuf = (__u8 *)data;
+               ops.oobbuf = (void *)&pt;
+               retval = mtd->write_oob(mtd, addr, &ops);
+       } else
+               BUG(); /* both tags and data should always be present */
+#else
+       if (tags) {
+               yaffs_PackTags2(&pt, tags);
+       }
+
+       if (data && tags) {
+               if (dev->useNANDECC)
+                       retval =
+                           mtd->write_ecc(mtd, addr, dev->nDataBytesPerChunk,
+                                          &dummy, data, (__u8 *) & pt, NULL);
+               else
+                       retval =
+                           mtd->write_ecc(mtd, addr, dev->nDataBytesPerChunk,
+                                          &dummy, data, (__u8 *) & pt, NULL);
+       } else {
+               if (data)
+                       retval =
+                           mtd->write(mtd, addr, dev->nDataBytesPerChunk, &dummy,
+                                      data);
+               if (tags)
+                       retval =
+                           mtd->write_oob(mtd, addr, mtd->oobsize, &dummy,
+                                          (__u8 *) & pt);
+
+       }
+#endif
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
+int nandmtd2_ReadChunkWithTagsFromNAND(yaffs_Device * dev, int chunkInNAND,
+                                      __u8 * data, yaffs_ExtendedTags * tags)
+{
+       struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+       struct mtd_oob_ops ops;
+#endif
+       size_t dummy;
+       int retval = 0;
+
+       loff_t addr = ((loff_t) chunkInNAND) * dev->nDataBytesPerChunk;
+
+       yaffs_PackedTags2 pt;
+
+       T(YAFFS_TRACE_MTD,
+         (TSTR
+          ("nandmtd2_ReadChunkWithTagsFromNAND chunk %d data %p tags %p"
+           TENDSTR), chunkInNAND, data, tags));
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
+       if (data && !tags)
+               retval = mtd->read(mtd, addr, dev->nDataBytesPerChunk,
+                               &dummy, data);
+       else if (tags) {
+               ops.mode = MTD_OOB_AUTO;
+               ops.ooblen = sizeof(pt);
+               ops.len = data ? dev->nDataBytesPerChunk : sizeof(pt);
+               ops.ooboffs = 0;
+               ops.datbuf = data;
+               ops.oobbuf = dev->spareBuffer;
+               retval = mtd->read_oob(mtd, addr, &ops);
+       }
+#else
+       if (data && tags) {
+               if (dev->useNANDECC) {
+                       retval =
+                           mtd->read_ecc(mtd, addr, dev->nDataBytesPerChunk,
+                                         &dummy, data, dev->spareBuffer,
+                                         NULL);
+               } else {
+                       retval =
+                           mtd->read_ecc(mtd, addr, dev->nDataBytesPerChunk,
+                                         &dummy, data, dev->spareBuffer,
+                                         NULL);
+               }
+       } else {
+               if (data)
+                       retval =
+                           mtd->read(mtd, addr, dev->nDataBytesPerChunk, &dummy,
+                                     data);
+               if (tags)
+                       retval =
+                           mtd->read_oob(mtd, addr, mtd->oobsize, &dummy,
+                                         dev->spareBuffer);
+       }
+#endif
+
+       memcpy(&pt, dev->spareBuffer, sizeof(pt));
+
+       if (tags)
+               yaffs_UnpackTags2(tags, &pt);
+       
+       if(tags && retval == -EBADMSG && tags->eccResult == YAFFS_ECC_RESULT_NO_ERROR)
+               tags->eccResult = YAFFS_ECC_RESULT_UNFIXED;
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
+int nandmtd2_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo)
+{
+       struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+       int retval;
+       T(YAFFS_TRACE_MTD,
+         (TSTR("nandmtd2_MarkNANDBlockBad %d" TENDSTR), blockNo));
+
+       retval =
+           mtd->block_markbad(mtd,
+                              blockNo * dev->nChunksPerBlock *
+                              dev->nDataBytesPerChunk);
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+
+}
+
+int nandmtd2_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo,
+                           yaffs_BlockState * state, int *sequenceNumber)
+{
+       struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+       int retval;
+
+       T(YAFFS_TRACE_MTD,
+         (TSTR("nandmtd2_QueryNANDBlock %d" TENDSTR), blockNo));
+       retval =
+           mtd->block_isbad(mtd,
+                            blockNo * dev->nChunksPerBlock *
+                            dev->nDataBytesPerChunk);
+
+       if (retval) {
+               T(YAFFS_TRACE_MTD, (TSTR("block is bad" TENDSTR)));
+
+               *state = YAFFS_BLOCK_STATE_DEAD;
+               *sequenceNumber = 0;
+       } else {
+               yaffs_ExtendedTags t;
+               nandmtd2_ReadChunkWithTagsFromNAND(dev,
+                                                  blockNo *
+                                                  dev->nChunksPerBlock, NULL,
+                                                  &t);
+
+               if (t.chunkUsed) {
+                       *sequenceNumber = t.sequenceNumber;
+                       *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+               } else {
+                       *sequenceNumber = 0;
+                       *state = YAFFS_BLOCK_STATE_EMPTY;
+               }
+       }
+       T(YAFFS_TRACE_MTD,
+         (TSTR("block is bad seq %d state %d" TENDSTR), *sequenceNumber,
+          *state));
+
+       if (retval == 0)
+               return YAFFS_OK;
+       else
+               return YAFFS_FAIL;
+}
+
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_mtdif2.h linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif2.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_mtdif2.h     1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_mtdif2.h 2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,29 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_MTDIF2_H__
+#define __YAFFS_MTDIF2_H__
+
+#include "yaffs_guts.h"
+int nandmtd2_WriteChunkWithTagsToNAND(yaffs_Device * dev, int chunkInNAND,
+                                     const __u8 * data,
+                                     const yaffs_ExtendedTags * tags);
+int nandmtd2_ReadChunkWithTagsFromNAND(yaffs_Device * dev, int chunkInNAND,
+                                      __u8 * data, yaffs_ExtendedTags * tags);
+int nandmtd2_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo);
+int nandmtd2_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo,
+                           yaffs_BlockState * state, int *sequenceNumber);
+
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_nand.c linux-2.6.21.1.new/fs/yaffs2/yaffs_nand.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_nand.c       1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_nand.c   2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,134 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+ 
+const char *yaffs_nand_c_version =
+    "$Id: yaffs_nand.c,v 1.7 2007-02-14 01:09:06 wookey Exp $";
+
+#include "yaffs_nand.h"
+#include "yaffs_tagscompat.h"
+#include "yaffs_tagsvalidity.h"
+
+
+int yaffs_ReadChunkWithTagsFromNAND(yaffs_Device * dev, int chunkInNAND,
+                                          __u8 * buffer,
+                                          yaffs_ExtendedTags * tags)
+{
+       int result;
+       yaffs_ExtendedTags localTags;
+       
+       int realignedChunkInNAND = chunkInNAND - dev->chunkOffset;
+       
+       /* If there are no tags provided, use local tags to get prioritised gc working */
+       if(!tags)
+               tags = &localTags;
+
+       if (dev->readChunkWithTagsFromNAND)
+               result = dev->readChunkWithTagsFromNAND(dev, realignedChunkInNAND, buffer,
+                                                     tags);
+       else
+               result = yaffs_TagsCompatabilityReadChunkWithTagsFromNAND(dev,
+                                                                       realignedChunkInNAND,
+                                                                       buffer,
+                                                                       tags);  
+       if(tags && 
+          tags->eccResult > YAFFS_ECC_RESULT_NO_ERROR){
+       
+               yaffs_BlockInfo *bi = yaffs_GetBlockInfo(dev, chunkInNAND/dev->nChunksPerBlock);
+                yaffs_HandleChunkError(dev,bi);
+       }
+                                                               
+       return result;
+}
+
+int yaffs_WriteChunkWithTagsToNAND(yaffs_Device * dev,
+                                                  int chunkInNAND,
+                                                  const __u8 * buffer,
+                                                  yaffs_ExtendedTags * tags)
+{
+       chunkInNAND -= dev->chunkOffset;
+
+       
+       if (tags) {
+               tags->sequenceNumber = dev->sequenceNumber;
+               tags->chunkUsed = 1;
+               if (!yaffs_ValidateTags(tags)) {
+                       T(YAFFS_TRACE_ERROR,
+                         (TSTR("Writing uninitialised tags" TENDSTR)));
+                       YBUG();
+               }
+               T(YAFFS_TRACE_WRITE,
+                 (TSTR("Writing chunk %d tags %d %d" TENDSTR), chunkInNAND,
+                  tags->objectId, tags->chunkId));
+       } else {
+               T(YAFFS_TRACE_ERROR, (TSTR("Writing with no tags" TENDSTR)));
+               YBUG();
+       }
+
+       if (dev->writeChunkWithTagsToNAND)
+               return dev->writeChunkWithTagsToNAND(dev, chunkInNAND, buffer,
+                                                    tags);
+       else
+               return yaffs_TagsCompatabilityWriteChunkWithTagsToNAND(dev,
+                                                                      chunkInNAND,
+                                                                      buffer,
+                                                                      tags);
+}
+
+int yaffs_MarkBlockBad(yaffs_Device * dev, int blockNo)
+{
+       blockNo -= dev->blockOffset;
+
+;
+       if (dev->markNANDBlockBad)
+               return dev->markNANDBlockBad(dev, blockNo);
+       else
+               return yaffs_TagsCompatabilityMarkNANDBlockBad(dev, blockNo);
+}
+
+int yaffs_QueryInitialBlockState(yaffs_Device * dev,
+                                                int blockNo,
+                                                yaffs_BlockState * state,
+                                                unsigned *sequenceNumber)
+{
+       blockNo -= dev->blockOffset;
+
+       if (dev->queryNANDBlock)
+               return dev->queryNANDBlock(dev, blockNo, state, sequenceNumber);
+       else
+               return yaffs_TagsCompatabilityQueryNANDBlock(dev, blockNo,
+                                                            state,
+                                                            sequenceNumber);
+}
+
+
+int yaffs_EraseBlockInNAND(struct yaffs_DeviceStruct *dev,
+                                 int blockInNAND)
+{
+       int result;
+
+       blockInNAND -= dev->blockOffset;
+
+
+       dev->nBlockErasures++;
+       result = dev->eraseBlockInNAND(dev, blockInNAND);
+
+       return result;
+}
+
+int yaffs_InitialiseNAND(struct yaffs_DeviceStruct *dev)
+{
+       return dev->initialiseNAND(dev);
+}
+
+
+ 
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_nand.h linux-2.6.21.1.new/fs/yaffs2/yaffs_nand.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_nand.h       1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_nand.h   2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,44 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_NAND_H__
+#define __YAFFS_NAND_H__
+#include "yaffs_guts.h"
+
+
+
+int yaffs_ReadChunkWithTagsFromNAND(yaffs_Device * dev, int chunkInNAND,
+                                          __u8 * buffer,
+                                          yaffs_ExtendedTags * tags);
+
+int yaffs_WriteChunkWithTagsToNAND(yaffs_Device * dev,
+                                                  int chunkInNAND,
+                                                  const __u8 * buffer,
+                                                  yaffs_ExtendedTags * tags);
+
+int yaffs_MarkBlockBad(yaffs_Device * dev, int blockNo);
+
+int yaffs_QueryInitialBlockState(yaffs_Device * dev,
+                                                int blockNo,
+                                                yaffs_BlockState * state,
+                                                unsigned *sequenceNumber);
+
+int yaffs_EraseBlockInNAND(struct yaffs_DeviceStruct *dev,
+                                 int blockInNAND);
+
+int yaffs_InitialiseNAND(struct yaffs_DeviceStruct *dev);
+
+#endif
+
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_nandemul2k.h linux-2.6.21.1.new/fs/yaffs2/yaffs_nandemul2k.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_nandemul2k.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_nandemul2k.h     2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,39 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/* Interface to emulated NAND functions (2k page size) */
+
+#ifndef __YAFFS_NANDEMUL2K_H__
+#define __YAFFS_NANDEMUL2K_H__
+
+#include "yaffs_guts.h"
+
+int nandemul2k_WriteChunkWithTagsToNAND(struct yaffs_DeviceStruct *dev,
+                                       int chunkInNAND, const __u8 * data,
+                                       yaffs_ExtendedTags * tags);
+int nandemul2k_ReadChunkWithTagsFromNAND(struct yaffs_DeviceStruct *dev,
+                                        int chunkInNAND, __u8 * data,
+                                        yaffs_ExtendedTags * tags);
+int nandemul2k_MarkNANDBlockBad(struct yaffs_DeviceStruct *dev, int blockNo);
+int nandemul2k_QueryNANDBlock(struct yaffs_DeviceStruct *dev, int blockNo,
+                             yaffs_BlockState * state, int *sequenceNumber);
+int nandemul2k_EraseBlockInNAND(struct yaffs_DeviceStruct *dev,
+                               int blockInNAND);
+int nandemul2k_InitialiseNAND(struct yaffs_DeviceStruct *dev);
+int nandemul2k_GetBytesPerChunk(void);
+int nandemul2k_GetChunksPerBlock(void);
+int nandemul2k_GetNumberOfBlocks(void);
+
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_packedtags1.c linux-2.6.21.1.new/fs/yaffs2/yaffs_packedtags1.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_packedtags1.c        1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_packedtags1.c    2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,52 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_packedtags1.h"
+#include "yportenv.h"
+
+void yaffs_PackTags1(yaffs_PackedTags1 * pt, const yaffs_ExtendedTags * t)
+{
+       pt->chunkId = t->chunkId;
+       pt->serialNumber = t->serialNumber;
+       pt->byteCount = t->byteCount;
+       pt->objectId = t->objectId;
+       pt->ecc = 0;
+       pt->deleted = (t->chunkDeleted) ? 0 : 1;
+       pt->unusedStuff = 0;
+       pt->shouldBeFF = 0xFFFFFFFF;
+
+}
+
+void yaffs_UnpackTags1(yaffs_ExtendedTags * t, const yaffs_PackedTags1 * pt)
+{
+       static const __u8 allFF[] =
+           { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+0xff };
+
+       if (memcmp(allFF, pt, sizeof(yaffs_PackedTags1))) {
+               t->blockBad = 0;
+               if (pt->shouldBeFF != 0xFFFFFFFF) {
+                       t->blockBad = 1;
+               }
+               t->chunkUsed = 1;
+               t->objectId = pt->objectId;
+               t->chunkId = pt->chunkId;
+               t->byteCount = pt->byteCount;
+               t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
+               t->chunkDeleted = (pt->deleted) ? 0 : 1;
+               t->serialNumber = pt->serialNumber;
+       } else {
+               memset(t, 0, sizeof(yaffs_ExtendedTags));
+
+       }
+}
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_packedtags1.h linux-2.6.21.1.new/fs/yaffs2/yaffs_packedtags1.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_packedtags1.h        1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_packedtags1.h    2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,37 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/* This is used to pack YAFFS1 tags, not YAFFS2 tags. */
+
+#ifndef __YAFFS_PACKEDTAGS1_H__
+#define __YAFFS_PACKEDTAGS1_H__
+
+#include "yaffs_guts.h"
+
+typedef struct {
+       unsigned chunkId:20;
+       unsigned serialNumber:2;
+       unsigned byteCount:10;
+       unsigned objectId:18;
+       unsigned ecc:12;
+       unsigned deleted:1;
+       unsigned unusedStuff:1;
+       unsigned shouldBeFF;
+
+} yaffs_PackedTags1;
+
+void yaffs_PackTags1(yaffs_PackedTags1 * pt, const yaffs_ExtendedTags * t);
+void yaffs_UnpackTags1(yaffs_ExtendedTags * t, const yaffs_PackedTags1 * pt);
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_packedtags2.c linux-2.6.21.1.new/fs/yaffs2/yaffs_packedtags2.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_packedtags2.c        1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_packedtags2.c    2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,182 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_packedtags2.h"
+#include "yportenv.h"
+#include "yaffs_tagsvalidity.h"
+
+/* This code packs a set of extended tags into a binary structure for
+ * NAND storage
+ */
+
+/* Some of the information is "extra" struff which can be packed in to
+ * speed scanning
+ * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
+ */
+
+/* Extra flags applied to chunkId */
+
+#define EXTRA_HEADER_INFO_FLAG 0x80000000
+#define EXTRA_SHRINK_FLAG      0x40000000
+#define EXTRA_SHADOWS_FLAG     0x20000000
+#define EXTRA_SPARE_FLAGS      0x10000000
+
+#define ALL_EXTRA_FLAGS                0xF0000000
+
+/* Also, the top 4 bits of the object Id are set to the object type. */
+#define EXTRA_OBJECT_TYPE_SHIFT (28)
+#define EXTRA_OBJECT_TYPE_MASK  ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
+
+static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 * pt)
+{
+       T(YAFFS_TRACE_MTD,
+         (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR),
+          pt->t.objectId, pt->t.chunkId, pt->t.byteCount,
+          pt->t.sequenceNumber));
+}
+
+static void yaffs_DumpTags2(const yaffs_ExtendedTags * t)
+{
+       T(YAFFS_TRACE_MTD,
+         (TSTR
+          ("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte "
+           "%d del %d ser %d seq %d"
+           TENDSTR), t->eccResult, t->blockBad, t->chunkUsed, t->objectId,
+          t->chunkId, t->byteCount, t->chunkDeleted, t->serialNumber,
+          t->sequenceNumber));
+
+}
+
+void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t)
+{
+       pt->t.chunkId = t->chunkId;
+       pt->t.sequenceNumber = t->sequenceNumber;
+       pt->t.byteCount = t->byteCount;
+       pt->t.objectId = t->objectId;
+
+       if (t->chunkId == 0 && t->extraHeaderInfoAvailable) {
+               /* Store the extra header info instead */
+               /* We save the parent object in the chunkId */
+               pt->t.chunkId = EXTRA_HEADER_INFO_FLAG
+                       | t->extraParentObjectId;
+               if (t->extraIsShrinkHeader) {
+                       pt->t.chunkId |= EXTRA_SHRINK_FLAG;
+               }
+               if (t->extraShadows) {
+                       pt->t.chunkId |= EXTRA_SHADOWS_FLAG;
+               }
+
+               pt->t.objectId &= ~EXTRA_OBJECT_TYPE_MASK;
+               pt->t.objectId |=
+                   (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
+
+               if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
+                       pt->t.byteCount = t->extraEquivalentObjectId;
+               } else if (t->extraObjectType == YAFFS_OBJECT_TYPE_FILE) {
+                       pt->t.byteCount = t->extraFileLength;
+               } else {
+                       pt->t.byteCount = 0;
+               }
+       }
+
+       yaffs_DumpPackedTags2(pt);
+       yaffs_DumpTags2(t);
+
+#ifndef YAFFS_IGNORE_TAGS_ECC
+       {
+               yaffs_ECCCalculateOther((unsigned char *)&pt->t,
+                                       sizeof(yaffs_PackedTags2TagsPart),
+                                       &pt->ecc);
+       }
+#endif
+}
+
+void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt)
+{
+
+       memset(t, 0, sizeof(yaffs_ExtendedTags));
+
+       yaffs_InitialiseTags(t);
+
+       if (pt->t.sequenceNumber != 0xFFFFFFFF) {
+               /* Page is in use */
+#ifdef YAFFS_IGNORE_TAGS_ECC
+               {
+                       t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
+               }
+#else
+               {
+                       yaffs_ECCOther ecc;
+                       int result;
+                       yaffs_ECCCalculateOther((unsigned char *)&pt->t,
+                                               sizeof
+                                               (yaffs_PackedTags2TagsPart),
+                                               &ecc);
+                       result =
+                           yaffs_ECCCorrectOther((unsigned char *)&pt->t,
+                                                 sizeof
+                                                 (yaffs_PackedTags2TagsPart),
+                                                 &pt->ecc, &ecc);
+                       switch(result){
+                               case 0: 
+                                       t->eccResult = YAFFS_ECC_RESULT_NO_ERROR; 
+                                       break;
+                               case 1: 
+                                       t->eccResult = YAFFS_ECC_RESULT_FIXED;
+                                       break;
+                               case -1:
+                                       t->eccResult = YAFFS_ECC_RESULT_UNFIXED;
+                                       break;
+                               default:
+                                       t->eccResult = YAFFS_ECC_RESULT_UNKNOWN;
+                       }
+               }
+#endif
+               t->blockBad = 0;
+               t->chunkUsed = 1;
+               t->objectId = pt->t.objectId;
+               t->chunkId = pt->t.chunkId;
+               t->byteCount = pt->t.byteCount;
+               t->chunkDeleted = 0;
+               t->serialNumber = 0;
+               t->sequenceNumber = pt->t.sequenceNumber;
+
+               /* Do extra header info stuff */
+
+               if (pt->t.chunkId & EXTRA_HEADER_INFO_FLAG) {
+                       t->chunkId = 0;
+                       t->byteCount = 0;
+
+                       t->extraHeaderInfoAvailable = 1;
+                       t->extraParentObjectId =
+                           pt->t.chunkId & (~(ALL_EXTRA_FLAGS));
+                       t->extraIsShrinkHeader =
+                           (pt->t.chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
+                       t->extraShadows =
+                           (pt->t.chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
+                       t->extraObjectType =
+                           pt->t.objectId >> EXTRA_OBJECT_TYPE_SHIFT;
+                       t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
+
+                       if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
+                               t->extraEquivalentObjectId = pt->t.byteCount;
+                       } else {
+                               t->extraFileLength = pt->t.byteCount;
+                       }
+               }
+       }
+
+       yaffs_DumpPackedTags2(pt);
+       yaffs_DumpTags2(t);
+
+}
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_packedtags2.h linux-2.6.21.1.new/fs/yaffs2/yaffs_packedtags2.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_packedtags2.h        1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_packedtags2.h    2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,38 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+/* This is used to pack YAFFS2 tags, not YAFFS1tags. */
+
+#ifndef __YAFFS_PACKEDTAGS2_H__
+#define __YAFFS_PACKEDTAGS2_H__
+
+#include "yaffs_guts.h"
+#include "yaffs_ecc.h"
+
+typedef struct {
+       unsigned sequenceNumber;
+       unsigned objectId;
+       unsigned chunkId;
+       unsigned byteCount;
+} yaffs_PackedTags2TagsPart;
+
+typedef struct {
+       yaffs_PackedTags2TagsPart t;
+       yaffs_ECCOther ecc;
+} yaffs_PackedTags2;
+
+void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t);
+void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt);
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_qsort.c linux-2.6.21.1.new/fs/yaffs2/yaffs_qsort.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_qsort.c      1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_qsort.c  2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 1992, 1993
+ *     The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "yportenv.h"
+//#include <linux/string.h>
+
+/*
+ * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
+ */
+#define swapcode(TYPE, parmi, parmj, n) {              \
+       long i = (n) / sizeof (TYPE);                   \
+       register TYPE *pi = (TYPE *) (parmi);           \
+       register TYPE *pj = (TYPE *) (parmj);           \
+       do {                                            \
+               register TYPE   t = *pi;                \
+               *pi++ = *pj;                            \
+               *pj++ = t;                              \
+        } while (--i > 0);                             \
+}
+
+#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
+       es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
+
+static __inline void
+swapfunc(char *a, char *b, int n, int swaptype)
+{
+       if (swaptype <= 1) 
+               swapcode(long, a, b, n)
+       else
+               swapcode(char, a, b, n)
+}
+
+#define swap(a, b)                                     \
+       if (swaptype == 0) {                            \
+               long t = *(long *)(a);                  \
+               *(long *)(a) = *(long *)(b);            \
+               *(long *)(b) = t;                       \
+       } else                                          \
+               swapfunc(a, b, es, swaptype)
+
+#define vecswap(a, b, n)       if ((n) > 0) swapfunc(a, b, n, swaptype)
+
+static __inline char *
+med3(char *a, char *b, char *c, int (*cmp)(const void *, const void *))
+{
+       return cmp(a, b) < 0 ?
+              (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
+              :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
+}
+
+#ifndef min
+#define min(a,b) (((a) < (b)) ? (a) : (b))
+#endif
+
+void
+yaffs_qsort(void *aa, size_t n, size_t es,
+       int (*cmp)(const void *, const void *))
+{
+       char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
+       int d, r, swaptype, swap_cnt;
+       register char *a = aa;
+
+loop:  SWAPINIT(a, es);
+       swap_cnt = 0;
+       if (n < 7) {
+               for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es)
+                       for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
+                            pl -= es)
+                               swap(pl, pl - es);
+               return;
+       }
+       pm = (char *)a + (n / 2) * es;
+       if (n > 7) {
+               pl = (char *)a;
+               pn = (char *)a + (n - 1) * es;
+               if (n > 40) {
+                       d = (n / 8) * es;
+                       pl = med3(pl, pl + d, pl + 2 * d, cmp);
+                       pm = med3(pm - d, pm, pm + d, cmp);
+                       pn = med3(pn - 2 * d, pn - d, pn, cmp);
+               }
+               pm = med3(pl, pm, pn, cmp);
+       }
+       swap(a, pm);
+       pa = pb = (char *)a + es;
+
+       pc = pd = (char *)a + (n - 1) * es;
+       for (;;) {
+               while (pb <= pc && (r = cmp(pb, a)) <= 0) {
+                       if (r == 0) {
+                               swap_cnt = 1;
+                               swap(pa, pb);
+                               pa += es;
+                       }
+                       pb += es;
+               }
+               while (pb <= pc && (r = cmp(pc, a)) >= 0) {
+                       if (r == 0) {
+                               swap_cnt = 1;
+                               swap(pc, pd);
+                               pd -= es;
+                       }
+                       pc -= es;
+               }
+               if (pb > pc)
+                       break;
+               swap(pb, pc);
+               swap_cnt = 1;
+               pb += es;
+               pc -= es;
+       }
+       if (swap_cnt == 0) {  /* Switch to insertion sort */
+               for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
+                       for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0; 
+                            pl -= es)
+                               swap(pl, pl - es);
+               return;
+       }
+
+       pn = (char *)a + n * es;
+       r = min(pa - (char *)a, pb - pa);
+       vecswap(a, pb - r, r);
+       r = min((long)(pd - pc), (long)(pn - pd - es));
+       vecswap(pb, pn - r, r);
+       if ((r = pb - pa) > es)
+               yaffs_qsort(a, r / es, es, cmp);
+       if ((r = pd - pc) > es) { 
+               /* Iterate rather than recurse to save stack space */
+               a = pn - r;
+               n = r / es;
+               goto loop;
+       }
+/*             yaffs_qsort(pn - r, r / es, es, cmp);*/
+}
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_qsort.h linux-2.6.21.1.new/fs/yaffs2/yaffs_qsort.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_qsort.h      1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_qsort.h  2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,23 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+
+#ifndef __YAFFS_QSORT_H__
+#define __YAFFS_QSORT_H__
+
+extern void yaffs_qsort (void *const base, size_t total_elems, size_t size,
+                   int (*cmp)(const void *, const void *));
+
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_tagscompat.c linux-2.6.21.1.new/fs/yaffs2/yaffs_tagscompat.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_tagscompat.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_tagscompat.c     2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,530 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_guts.h"
+#include "yaffs_tagscompat.h"
+#include "yaffs_ecc.h"
+
+static void yaffs_HandleReadDataError(yaffs_Device * dev, int chunkInNAND);
+#ifdef NOTYET
+static void yaffs_CheckWrittenBlock(yaffs_Device * dev, int chunkInNAND);
+static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
+                                    const __u8 * data,
+                                    const yaffs_Spare * spare);
+static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
+                                   const yaffs_Spare * spare);
+static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND);
+#endif
+
+static const char yaffs_countBitsTable[256] = {
+       0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
+       1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
+       1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
+       2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
+       1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
+       2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
+       2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
+       3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
+       1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
+       2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
+       2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
+       3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
+       2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
+       3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
+       3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
+       4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
+};
+
+int yaffs_CountBits(__u8 x)
+{
+       int retVal;
+       retVal = yaffs_countBitsTable[x];
+       return retVal;
+}
+
+/********** Tags ECC calculations  *********/
+
+void yaffs_CalcECC(const __u8 * data, yaffs_Spare * spare)
+{
+       yaffs_ECCCalculate(data, spare->ecc1);
+       yaffs_ECCCalculate(&data[256], spare->ecc2);
+}
+
+void yaffs_CalcTagsECC(yaffs_Tags * tags)
+{
+       /* Calculate an ecc */
+
+       unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes;
+       unsigned i, j;
+       unsigned ecc = 0;
+       unsigned bit = 0;
+
+       tags->ecc = 0;
+
+       for (i = 0; i < 8; i++) {
+               for (j = 1; j & 0xff; j <<= 1) {
+                       bit++;
+                       if (b[i] & j) {
+                               ecc ^= bit;
+                       }
+               }
+       }
+
+       tags->ecc = ecc;
+
+}
+
+int yaffs_CheckECCOnTags(yaffs_Tags * tags)
+{
+       unsigned ecc = tags->ecc;
+
+       yaffs_CalcTagsECC(tags);
+
+       ecc ^= tags->ecc;
+
+       if (ecc && ecc <= 64) {
+               /* TODO: Handle the failure better. Retire? */
+               unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes;
+
+               ecc--;
+
+               b[ecc / 8] ^= (1 << (ecc & 7));
+
+               /* Now recvalc the ecc */
+               yaffs_CalcTagsECC(tags);
+
+               return 1;       /* recovered error */
+       } else if (ecc) {
+               /* Wierd ecc failure value */
+               /* TODO Need to do somethiong here */
+               return -1;      /* unrecovered error */
+       }
+
+       return 0;
+}
+
+/********** Tags **********/
+
+static void yaffs_LoadTagsIntoSpare(yaffs_Spare * sparePtr,
+                                   yaffs_Tags * tagsPtr)
+{
+       yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr;
+
+       yaffs_CalcTagsECC(tagsPtr);
+
+       sparePtr->tagByte0 = tu->asBytes[0];
+       sparePtr->tagByte1 = tu->asBytes[1];
+       sparePtr->tagByte2 = tu->asBytes[2];
+       sparePtr->tagByte3 = tu->asBytes[3];
+       sparePtr->tagByte4 = tu->asBytes[4];
+       sparePtr->tagByte5 = tu->asBytes[5];
+       sparePtr->tagByte6 = tu->asBytes[6];
+       sparePtr->tagByte7 = tu->asBytes[7];
+}
+
+static void yaffs_GetTagsFromSpare(yaffs_Device * dev, yaffs_Spare * sparePtr,
+                                  yaffs_Tags * tagsPtr)
+{
+       yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr;
+       int result;
+
+       tu->asBytes[0] = sparePtr->tagByte0;
+       tu->asBytes[1] = sparePtr->tagByte1;
+       tu->asBytes[2] = sparePtr->tagByte2;
+       tu->asBytes[3] = sparePtr->tagByte3;
+       tu->asBytes[4] = sparePtr->tagByte4;
+       tu->asBytes[5] = sparePtr->tagByte5;
+       tu->asBytes[6] = sparePtr->tagByte6;
+       tu->asBytes[7] = sparePtr->tagByte7;
+
+       result = yaffs_CheckECCOnTags(tagsPtr);
+       if (result > 0) {
+               dev->tagsEccFixed++;
+       } else if (result < 0) {
+               dev->tagsEccUnfixed++;
+       }
+}
+
+static void yaffs_SpareInitialise(yaffs_Spare * spare)
+{
+       memset(spare, 0xFF, sizeof(yaffs_Spare));
+}
+
+static int yaffs_WriteChunkToNAND(struct yaffs_DeviceStruct *dev,
+                                 int chunkInNAND, const __u8 * data,
+                                 yaffs_Spare * spare)
+{
+       if (chunkInNAND < dev->startBlock * dev->nChunksPerBlock) {
+               T(YAFFS_TRACE_ERROR,
+                 (TSTR("**>> yaffs chunk %d is not valid" TENDSTR),
+                  chunkInNAND));
+               return YAFFS_FAIL;
+       }
+
+       dev->nPageWrites++;
+       return dev->writeChunkToNAND(dev, chunkInNAND, data, spare);
+}
+
+static int yaffs_ReadChunkFromNAND(struct yaffs_DeviceStruct *dev,
+                                  int chunkInNAND,
+                                  __u8 * data,
+                                  yaffs_Spare * spare,
+                                  yaffs_ECCResult * eccResult,
+                                  int doErrorCorrection)
+{
+       int retVal;
+       yaffs_Spare localSpare;
+
+       dev->nPageReads++;
+
+       if (!spare && data) {
+               /* If we don't have a real spare, then we use a local one. */
+               /* Need this for the calculation of the ecc */
+               spare = &localSpare;
+       }
+
+       if (!dev->useNANDECC) {
+               retVal = dev->readChunkFromNAND(dev, chunkInNAND, data, spare);
+               if (data && doErrorCorrection) {
+                       /* Do ECC correction */
+                       /* Todo handle any errors */
+                       int eccResult1, eccResult2;
+                       __u8 calcEcc[3];
+
+                       yaffs_ECCCalculate(data, calcEcc);
+                       eccResult1 =
+                           yaffs_ECCCorrect(data, spare->ecc1, calcEcc);
+                       yaffs_ECCCalculate(&data[256], calcEcc);
+                       eccResult2 =
+                           yaffs_ECCCorrect(&data[256], spare->ecc2, calcEcc);
+
+                       if (eccResult1 > 0) {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  ("**>>yaffs ecc error fix performed on chunk %d:0"
+                                   TENDSTR), chunkInNAND));
+                               dev->eccFixed++;
+                       } else if (eccResult1 < 0) {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  ("**>>yaffs ecc error unfixed on chunk %d:0"
+                                   TENDSTR), chunkInNAND));
+                               dev->eccUnfixed++;
+                       }
+
+                       if (eccResult2 > 0) {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  ("**>>yaffs ecc error fix performed on chunk %d:1"
+                                   TENDSTR), chunkInNAND));
+                               dev->eccFixed++;
+                       } else if (eccResult2 < 0) {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  ("**>>yaffs ecc error unfixed on chunk %d:1"
+                                   TENDSTR), chunkInNAND));
+                               dev->eccUnfixed++;
+                       }
+
+                       if (eccResult1 || eccResult2) {
+                               /* We had a data problem on this page */
+                               yaffs_HandleReadDataError(dev, chunkInNAND);
+                       }
+
+                       if (eccResult1 < 0 || eccResult2 < 0)
+                               *eccResult = YAFFS_ECC_RESULT_UNFIXED;
+                       else if (eccResult1 > 0 || eccResult2 > 0)
+                               *eccResult = YAFFS_ECC_RESULT_FIXED;
+                       else
+                               *eccResult = YAFFS_ECC_RESULT_NO_ERROR;
+               }
+       } else {
+               /* Must allocate enough memory for spare+2*sizeof(int) */
+               /* for ecc results from device. */
+               struct yaffs_NANDSpare nspare;
+               retVal =
+                   dev->readChunkFromNAND(dev, chunkInNAND, data,
+                                          (yaffs_Spare *) & nspare);
+               memcpy(spare, &nspare, sizeof(yaffs_Spare));
+               if (data && doErrorCorrection) {
+                       if (nspare.eccres1 > 0) {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  ("**>>mtd ecc error fix performed on chunk %d:0"
+                                   TENDSTR), chunkInNAND));
+                       } else if (nspare.eccres1 < 0) {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  ("**>>mtd ecc error unfixed on chunk %d:0"
+                                   TENDSTR), chunkInNAND));
+                       }
+
+                       if (nspare.eccres2 > 0) {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  ("**>>mtd ecc error fix performed on chunk %d:1"
+                                   TENDSTR), chunkInNAND));
+                       } else if (nspare.eccres2 < 0) {
+                               T(YAFFS_TRACE_ERROR,
+                                 (TSTR
+                                  ("**>>mtd ecc error unfixed on chunk %d:1"
+                                   TENDSTR), chunkInNAND));
+                       }
+
+                       if (nspare.eccres1 || nspare.eccres2) {
+                               /* We had a data problem on this page */
+                               yaffs_HandleReadDataError(dev, chunkInNAND);
+                       }
+
+                       if (nspare.eccres1 < 0 || nspare.eccres2 < 0)
+                               *eccResult = YAFFS_ECC_RESULT_UNFIXED;
+                       else if (nspare.eccres1 > 0 || nspare.eccres2 > 0)
+                               *eccResult = YAFFS_ECC_RESULT_FIXED;
+                       else
+                               *eccResult = YAFFS_ECC_RESULT_NO_ERROR;
+
+               }
+       }
+       return retVal;
+}
+
+#ifdef NOTYET
+static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
+                                 int chunkInNAND)
+{
+
+       static int init = 0;
+       static __u8 cmpbuf[YAFFS_BYTES_PER_CHUNK];
+       static __u8 data[YAFFS_BYTES_PER_CHUNK];
+       /* Might as well always allocate the larger size for */
+       /* dev->useNANDECC == true; */
+       static __u8 spare[sizeof(struct yaffs_NANDSpare)];
+
+       dev->readChunkFromNAND(dev, chunkInNAND, data, (yaffs_Spare *) spare);
+
+       if (!init) {
+               memset(cmpbuf, 0xff, YAFFS_BYTES_PER_CHUNK);
+               init = 1;
+       }
+
+       if (memcmp(cmpbuf, data, YAFFS_BYTES_PER_CHUNK))
+               return YAFFS_FAIL;
+       if (memcmp(cmpbuf, spare, 16))
+               return YAFFS_FAIL;
+
+       return YAFFS_OK;
+
+}
+#endif
+
+/*
+ * Functions for robustisizing
+ */
+
+static void yaffs_HandleReadDataError(yaffs_Device * dev, int chunkInNAND)
+{
+       int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
+
+       /* Mark the block for retirement */
+       yaffs_GetBlockInfo(dev, blockInNAND)->needsRetiring = 1;
+       T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
+         (TSTR("**>>Block %d marked for retirement" TENDSTR), blockInNAND));
+
+       /* TODO:
+        * Just do a garbage collection on the affected block
+        * then retire the block
+        * NB recursion
+        */
+}
+
+#ifdef NOTYET
+static void yaffs_CheckWrittenBlock(yaffs_Device * dev, int chunkInNAND)
+{
+}
+
+static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
+                                    const __u8 * data,
+                                    const yaffs_Spare * spare)
+{
+}
+
+static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
+                                   const yaffs_Spare * spare)
+{
+}
+
+static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND)
+{
+       int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
+
+       /* Mark the block for retirement */
+       yaffs_GetBlockInfo(dev, blockInNAND)->needsRetiring = 1;
+       /* Delete the chunk */
+       yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
+}
+
+static int yaffs_VerifyCompare(const __u8 * d0, const __u8 * d1,
+                              const yaffs_Spare * s0, const yaffs_Spare * s1)
+{
+
+       if (memcmp(d0, d1, YAFFS_BYTES_PER_CHUNK) != 0 ||
+           s0->tagByte0 != s1->tagByte0 ||
+           s0->tagByte1 != s1->tagByte1 ||
+           s0->tagByte2 != s1->tagByte2 ||
+           s0->tagByte3 != s1->tagByte3 ||
+           s0->tagByte4 != s1->tagByte4 ||
+           s0->tagByte5 != s1->tagByte5 ||
+           s0->tagByte6 != s1->tagByte6 ||
+           s0->tagByte7 != s1->tagByte7 ||
+           s0->ecc1[0] != s1->ecc1[0] ||
+           s0->ecc1[1] != s1->ecc1[1] ||
+           s0->ecc1[2] != s1->ecc1[2] ||
+           s0->ecc2[0] != s1->ecc2[0] ||
+           s0->ecc2[1] != s1->ecc2[1] || s0->ecc2[2] != s1->ecc2[2]) {
+               return 0;
+       }
+
+       return 1;
+}
+#endif                         /* NOTYET */
+
+int yaffs_TagsCompatabilityWriteChunkWithTagsToNAND(yaffs_Device * dev,
+                                                   int chunkInNAND,
+                                                   const __u8 * data,
+                                                   const yaffs_ExtendedTags *
+                                                   eTags)
+{
+       yaffs_Spare spare;
+       yaffs_Tags tags;
+
+       yaffs_SpareInitialise(&spare);
+
+       if (eTags->chunkDeleted) {
+               spare.pageStatus = 0;
+       } else {
+               tags.objectId = eTags->objectId;
+               tags.chunkId = eTags->chunkId;
+               tags.byteCount = eTags->byteCount;
+               tags.serialNumber = eTags->serialNumber;
+
+               if (!dev->useNANDECC && data) {
+                       yaffs_CalcECC(data, &spare);
+               }
+               yaffs_LoadTagsIntoSpare(&spare, &tags);
+
+       }
+
+       return yaffs_WriteChunkToNAND(dev, chunkInNAND, data, &spare);
+}
+
+int yaffs_TagsCompatabilityReadChunkWithTagsFromNAND(yaffs_Device * dev,
+                                                    int chunkInNAND,
+                                                    __u8 * data,
+                                                    yaffs_ExtendedTags * eTags)
+{
+
+       yaffs_Spare spare;
+       yaffs_Tags tags;
+       yaffs_ECCResult eccResult;
+
+       static yaffs_Spare spareFF;
+       static int init;
+
+       if (!init) {
+               memset(&spareFF, 0xFF, sizeof(spareFF));
+               init = 1;
+       }
+
+       if (yaffs_ReadChunkFromNAND
+           (dev, chunkInNAND, data, &spare, &eccResult, 1)) {
+               /* eTags may be NULL */
+               if (eTags) {
+
+                       int deleted =
+                           (yaffs_CountBits(spare.pageStatus) < 7) ? 1 : 0;
+
+                       eTags->chunkDeleted = deleted;
+                       eTags->eccResult = eccResult;
+                       eTags->blockBad = 0;    /* We're reading it */
+                       /* therefore it is not a bad block */
+                       eTags->chunkUsed =
+                           (memcmp(&spareFF, &spare, sizeof(spareFF)) !=
+                            0) ? 1 : 0;
+
+                       if (eTags->chunkUsed) {
+                               yaffs_GetTagsFromSpare(dev, &spare, &tags);
+
+                               eTags->objectId = tags.objectId;
+                               eTags->chunkId = tags.chunkId;
+                               eTags->byteCount = tags.byteCount;
+                               eTags->serialNumber = tags.serialNumber;
+                       }
+               }
+
+               return YAFFS_OK;
+       } else {
+               return YAFFS_FAIL;
+       }
+}
+
+int yaffs_TagsCompatabilityMarkNANDBlockBad(struct yaffs_DeviceStruct *dev,
+                                           int blockInNAND)
+{
+
+       yaffs_Spare spare;
+
+       memset(&spare, 0xff, sizeof(yaffs_Spare));
+
+       spare.blockStatus = 'Y';
+
+       yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock, NULL,
+                              &spare);
+       yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock + 1,
+                              NULL, &spare);
+
+       return YAFFS_OK;
+
+}
+
+int yaffs_TagsCompatabilityQueryNANDBlock(struct yaffs_DeviceStruct *dev,
+                                         int blockNo, yaffs_BlockState *
+                                         state,
+                                         int *sequenceNumber)
+{
+
+       yaffs_Spare spare0, spare1;
+       static yaffs_Spare spareFF;
+       static int init;
+       yaffs_ECCResult dummy;
+
+       if (!init) {
+               memset(&spareFF, 0xFF, sizeof(spareFF));
+               init = 1;
+       }
+
+       *sequenceNumber = 0;
+
+       yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock, NULL,
+                               &spare0, &dummy, 1);
+       yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock + 1, NULL,
+                               &spare1, &dummy, 1);
+
+       if (yaffs_CountBits(spare0.blockStatus & spare1.blockStatus) < 7)
+               *state = YAFFS_BLOCK_STATE_DEAD;
+       else if (memcmp(&spareFF, &spare0, sizeof(spareFF)) == 0)
+               *state = YAFFS_BLOCK_STATE_EMPTY;
+       else
+               *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
+
+       return YAFFS_OK;
+}
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_tagscompat.h linux-2.6.21.1.new/fs/yaffs2/yaffs_tagscompat.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_tagscompat.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_tagscompat.h     2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,40 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFS_TAGSCOMPAT_H__
+#define __YAFFS_TAGSCOMPAT_H__
+
+#include "yaffs_guts.h"
+int yaffs_TagsCompatabilityWriteChunkWithTagsToNAND(yaffs_Device * dev,
+                                                   int chunkInNAND,
+                                                   const __u8 * data,
+                                                   const yaffs_ExtendedTags *
+                                                   tags);
+int yaffs_TagsCompatabilityReadChunkWithTagsFromNAND(yaffs_Device * dev,
+                                                    int chunkInNAND,
+                                                    __u8 * data,
+                                                    yaffs_ExtendedTags *
+                                                    tags);
+int yaffs_TagsCompatabilityMarkNANDBlockBad(struct yaffs_DeviceStruct *dev,
+                                           int blockNo);
+int yaffs_TagsCompatabilityQueryNANDBlock(struct yaffs_DeviceStruct *dev,
+                                         int blockNo, yaffs_BlockState *
+                                         state, int *sequenceNumber);
+
+void yaffs_CalcTagsECC(yaffs_Tags * tags);
+int yaffs_CheckECCOnTags(yaffs_Tags * tags);
+int yaffs_CountBits(__u8 byte);
+
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_tagsvalidity.c linux-2.6.21.1.new/fs/yaffs2/yaffs_tagsvalidity.c
--- linux-2.6.21.1/fs/yaffs2/yaffs_tagsvalidity.c       1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_tagsvalidity.c   2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,28 @@
+/*
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "yaffs_tagsvalidity.h"
+
+void yaffs_InitialiseTags(yaffs_ExtendedTags * tags)
+{
+       memset(tags, 0, sizeof(yaffs_ExtendedTags));
+       tags->validMarker0 = 0xAAAAAAAA;
+       tags->validMarker1 = 0x55555555;
+}
+
+int yaffs_ValidateTags(yaffs_ExtendedTags * tags)
+{
+       return (tags->validMarker0 == 0xAAAAAAAA &&
+               tags->validMarker1 == 0x55555555);
+
+}
diff -urN linux-2.6.21.1/fs/yaffs2/yaffs_tagsvalidity.h linux-2.6.21.1.new/fs/yaffs2/yaffs_tagsvalidity.h
--- linux-2.6.21.1/fs/yaffs2/yaffs_tagsvalidity.h       1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffs_tagsvalidity.h   2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,24 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+
+#ifndef __YAFFS_TAGS_VALIDITY_H__
+#define __YAFFS_TAGS_VALIDITY_H__
+
+#include "yaffs_guts.h"
+
+void yaffs_InitialiseTags(yaffs_ExtendedTags * tags);
+int yaffs_ValidateTags(yaffs_ExtendedTags * tags);
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yaffsinterface.h linux-2.6.21.1.new/fs/yaffs2/yaffsinterface.h
--- linux-2.6.21.1/fs/yaffs2/yaffsinterface.h   1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yaffsinterface.h       2007-06-08 14:07:26.000000000 +0200
@@ -0,0 +1,21 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+#ifndef __YAFFSINTERFACE_H__
+#define __YAFFSINTERFACE_H__
+
+int yaffs_Initialise(unsigned nBlocks);
+
+#endif
diff -urN linux-2.6.21.1/fs/yaffs2/yportenv.h linux-2.6.21.1.new/fs/yaffs2/yportenv.h
--- linux-2.6.21.1/fs/yaffs2/yportenv.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.21.1.new/fs/yaffs2/yportenv.h     2007-06-08 14:07:27.000000000 +0200
@@ -0,0 +1,186 @@
+/*
+ * YAFFS: Yet another Flash File System . A NAND-flash specific file system. 
+ *
+ * Copyright (C) 2002-2007 Aleph One Ltd.
+ *   for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1 as
+ * published by the Free Software Foundation.
+ *
+ * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
+ */
+
+
+#ifndef __YPORTENV_H__
+#define __YPORTENV_H__
+
+#if defined CONFIG_YAFFS_WINCE
+
+#include "ywinceenv.h"
+
+#elif  defined __KERNEL__
+
+#include "moduleconfig.h"
+
+/* Linux kernel */
+#include <linux/version.h>
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
+#include <linux/config.h>
+#endif
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#define YCHAR char
+#define YUCHAR unsigned char
+#define _Y(x)     x
+#define yaffs_strcpy(a,b)    strcpy(a,b)
+#define yaffs_strncpy(a,b,c) strncpy(a,b,c)
+#define yaffs_strncmp(a,b,c) strncmp(a,b,c)
+#define yaffs_strlen(s)             strlen(s)
+#define yaffs_sprintf       sprintf
+#define yaffs_toupper(a)     toupper(a)
+
+#define Y_INLINE inline
+
+#define YAFFS_LOSTNFOUND_NAME          "lost+found"
+#define YAFFS_LOSTNFOUND_PREFIX                "obj"
+
+/* #define YPRINTF(x) printk x */
+#define YMALLOC(x) kmalloc(x,GFP_KERNEL)
+#define YFREE(x)   kfree(x)
+#define YMALLOC_ALT(x) vmalloc(x)
+#define YFREE_ALT(x)   vfree(x)
+#define YMALLOC_DMA(x) YMALLOC(x)
+
+// KR - added for use in scan so processes aren't blocked indefinitely.
+#define YYIELD() schedule()
+
+#define YAFFS_ROOT_MODE                        0666
+#define YAFFS_LOSTNFOUND_MODE          0666
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+#define Y_CURRENT_TIME CURRENT_TIME.tv_sec
+#define Y_TIME_CONVERT(x) (x).tv_sec
+#else
+#define Y_CURRENT_TIME CURRENT_TIME
+#define Y_TIME_CONVERT(x) (x)
+#endif
+
+#define yaffs_SumCompare(x,y) ((x) == (y))
+#define yaffs_strcmp(a,b) strcmp(a,b)
+
+#define TENDSTR "\n"
+#define TSTR(x) KERN_WARNING x
+#define TOUT(p) printk p
+
+#define yaffs_trace(mask, fmt, args...) \
+       do { if ((mask) & (yaffs_traceMask|YAFFS_TRACE_ERROR)) \
+               printk(KERN_WARNING "yaffs: " fmt, ## args); \
+       } while (0)
+
+#define compile_time_assertion(assertion) \
+       ({ int x = __builtin_choose_expr(assertion, 0, (void)0); (void) x; })
+
+#elif defined CONFIG_YAFFS_DIRECT
+
+/* Direct interface */
+#include "ydirectenv.h"
+
+#elif defined CONFIG_YAFFS_UTIL
+
+/* Stuff for YAFFS utilities */
+
+#include "stdlib.h"
+#include "stdio.h"
+#include "string.h"
+
+#include "devextras.h"
+
+#define YMALLOC(x) malloc(x)
+#define YFREE(x)   free(x)
+#define YMALLOC_ALT(x) malloc(x)
+#define YFREE_ALT(x) free(x)
+
+#define YCHAR char
+#define YUCHAR unsigned char
+#define _Y(x)     x
+#define yaffs_strcpy(a,b)    strcpy(a,b)
+#define yaffs_strncpy(a,b,c) strncpy(a,b,c)
+#define yaffs_strlen(s)             strlen(s)
+#define yaffs_sprintf       sprintf
+#define yaffs_toupper(a)     toupper(a)
+
+#define Y_INLINE inline
+
+/* #define YINFO(s) YPRINTF(( __FILE__ " %d %s\n",__LINE__,s)) */
+/* #define YALERT(s) YINFO(s) */
+
+#define TENDSTR "\n"
+#define TSTR(x) x
+#define TOUT(p) printf p
+
+#define YAFFS_LOSTNFOUND_NAME          "lost+found"
+#define YAFFS_LOSTNFOUND_PREFIX                "obj"
+/* #define YPRINTF(x) printf x */
+
+#define YAFFS_ROOT_MODE                                0666
+#define YAFFS_LOSTNFOUND_MODE          0666
+
+#define yaffs_SumCompare(x,y) ((x) == (y))
+#define yaffs_strcmp(a,b) strcmp(a,b)
+
+#else
+/* Should have specified a configuration type */
+#error Unknown configuration
+
+#endif
+
+/* see yaffs_fs.c */
+extern unsigned int yaffs_traceMask;
+extern unsigned int yaffs_wr_attempts;
+
+/*
+ * Tracing flags.
+ * The flags masked in YAFFS_TRACE_ALWAYS are always traced.
+ */
+ 
+#define YAFFS_TRACE_OS                 0x00000002
+#define YAFFS_TRACE_ALLOCATE           0x00000004
+#define YAFFS_TRACE_SCAN               0x00000008
+#define YAFFS_TRACE_BAD_BLOCKS         0x00000010
+#define YAFFS_TRACE_ERASE              0x00000020
+#define YAFFS_TRACE_GC                 0x00000040
+#define YAFFS_TRACE_WRITE              0x00000080
+#define YAFFS_TRACE_TRACING            0x00000100
+#define YAFFS_TRACE_DELETION           0x00000200
+#define YAFFS_TRACE_BUFFERS            0x00000400
+#define YAFFS_TRACE_NANDACCESS         0x00000800
+#define YAFFS_TRACE_GC_DETAIL          0x00001000
+#define YAFFS_TRACE_SCAN_DEBUG         0x00002000
+#define YAFFS_TRACE_MTD                        0x00004000
+#define YAFFS_TRACE_CHECKPOINT         0x00008000
+
+#define YAFFS_TRACE_VERIFY             0x00010000
+#define YAFFS_TRACE_VERIFY_NAND                0x00020000
+#define YAFFS_TRACE_VERIFY_FULL                0x00040000
+#define YAFFS_TRACE_VERIFY_ALL         0x000F0000
+
+
+#define YAFFS_TRACE_ERROR              0x40000000
+#define YAFFS_TRACE_BUG                        0x80000000
+#define YAFFS_TRACE_ALWAYS             0xF0000000
+
+
+#define T(mask,p) do{ if((mask) & (yaffs_traceMask | YAFFS_TRACE_ALWAYS)) TOUT(p);} while(0)
+
+#ifndef CONFIG_YAFFS_WINCE
+#define YBUG() T(YAFFS_TRACE_BUG,(TSTR("==>> yaffs bug: " __FILE__ " %d" TENDSTR),__LINE__))
+#endif
+
+#endif