target/linux/generic-2.6/patches-2.6.31/001-squashfs_move_zlib_decomp.patch

   1 From 6c4419d997d4431bb62e73475cd6b084e83efbd1 Mon Sep 17 00:00:00 2001
   2 From: Phillip Lougher <phillip@lougher.demon.co.uk>
   3 Date: Tue, 22 Sep 2009 19:25:24 +0100
   4 Subject: [PATCH] Squashfs: move zlib decompression wrapper code into a separate file
   5
   6 Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
   7 ---
   8  fs/squashfs/Makefile       |    2 +-
   9  fs/squashfs/block.c        |   74 ++----------------------------
  10  fs/squashfs/squashfs.h     |    4 ++
  11  fs/squashfs/zlib_wrapper.c |  109 ++++++++++++++++++++++++++++++++++++++++++++
  12  4 files changed, 118 insertions(+), 71 deletions(-)
  13  create mode 100644 fs/squashfs/zlib_wrapper.c
  14
  15 --- a/fs/squashfs/Makefile
  16 +++ b/fs/squashfs/Makefile
  17 @@ -4,4 +4,4 @@
  18
  19  obj-$(CONFIG_SQUASHFS) += squashfs.o
  20  squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
  21 -squashfs-y += namei.o super.o symlink.o
  22 +squashfs-y += namei.o super.o symlink.o zlib_wrapper.o
  23 --- a/fs/squashfs/block.c
  24 +++ b/fs/squashfs/block.c
  25 @@ -29,7 +29,6 @@
  26  #include <linux/fs.h>
  27  #include <linux/vfs.h>
  28  #include <linux/slab.h>
  29 -#include <linux/mutex.h>
  30  #include <linux/string.h>
  31  #include <linux/buffer_head.h>
  32  #include <linux/zlib.h>
  33 @@ -153,72 +152,10 @@ int squashfs_read_data(struct super_bloc
  34         }
  35
  36         if (compressed) {
  37 -               int zlib_err = 0, zlib_init = 0;
  38 -
  39 -               /*
  40 -                * Uncompress block.
  41 -                */
  42 -
  43 -               mutex_lock(&msblk->read_data_mutex);
  44 -
  45 -               msblk->stream.avail_out = 0;
  46 -               msblk->stream.avail_in = 0;
  47 -
  48 -               bytes = length;
  49 -               do {
  50 -                       if (msblk->stream.avail_in == 0 && k < b) {
  51 -                               avail = min(bytes, msblk->devblksize - offset);
  52 -                               bytes -= avail;
  53 -                               wait_on_buffer(bh[k]);
  54 -                               if (!buffer_uptodate(bh[k]))
  55 -                                       goto release_mutex;
  56 -
  57 -                               if (avail == 0) {
  58 -                                       offset = 0;
  59 -                                       put_bh(bh[k++]);
  60 -                                       continue;
  61 -                               }
  62 -
  63 -                               msblk->stream.next_in = bh[k]->b_data + offset;
  64 -                               msblk->stream.avail_in = avail;
  65 -                               offset = 0;
  66 -                       }
  67 -
  68 -                       if (msblk->stream.avail_out == 0 && page < pages) {
  69 -                               msblk->stream.next_out = buffer[page++];
  70 -                               msblk->stream.avail_out = PAGE_CACHE_SIZE;
  71 -                       }
  72 -
  73 -                       if (!zlib_init) {
  74 -                               zlib_err = zlib_inflateInit(&msblk->stream);
  75 -                               if (zlib_err != Z_OK) {
  76 -                                       ERROR("zlib_inflateInit returned"
  77 -                                               " unexpected result 0x%x,"
  78 -                                               " srclength %d\n", zlib_err,
  79 -                                               srclength);
  80 -                                       goto release_mutex;
  81 -                               }
  82 -                               zlib_init = 1;
  83 -                       }
  84 -
  85 -                       zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH);
  86 -
  87 -                       if (msblk->stream.avail_in == 0 && k < b)
  88 -                               put_bh(bh[k++]);
  89 -               } while (zlib_err == Z_OK);
  90 -
  91 -               if (zlib_err != Z_STREAM_END) {
  92 -                       ERROR("zlib_inflate error, data probably corrupt\n");
  93 -                       goto release_mutex;
  94 -               }
  95 -
  96 -               zlib_err = zlib_inflateEnd(&msblk->stream);
  97 -               if (zlib_err != Z_OK) {
  98 -                       ERROR("zlib_inflate error, data probably corrupt\n");
  99 -                       goto release_mutex;
 100 -               }
 101 -               length = msblk->stream.total_out;
 102 -               mutex_unlock(&msblk->read_data_mutex);
 103 +               length = zlib_uncompress(msblk, buffer, bh, b, offset, length,
 104 +                       srclength, pages);
 105 +               if (length < 0)
 106 +                       goto read_failure;
 107         } else {
 108                 /*
 109                  * Block is uncompressed.
 110 @@ -255,9 +192,6 @@ int squashfs_read_data(struct super_bloc
 111         kfree(bh);
 112         return length;
 113
 114 -release_mutex:
 115 -       mutex_unlock(&msblk->read_data_mutex);
 116 -
 117  block_release:
 118         for (; k < b; k++)
 119                 put_bh(bh[k]);
 120 --- a/fs/squashfs/squashfs.h
 121 +++ b/fs/squashfs/squashfs.h
 122 @@ -70,6 +70,10 @@ extern struct inode *squashfs_iget(struc
 123                                 unsigned int);
 124  extern int squashfs_read_inode(struct inode *, long long);
 125
 126 +/* zlib_wrapper.c */
 127 +extern int zlib_uncompress(struct squashfs_sb_info *, void **,
 128 +                               struct buffer_head **, int, int, int, int, int);
 129 +
 130  /*
 131   * Inodes and files operations
 132   */
 133 --- /dev/null
 134 +++ b/fs/squashfs/zlib_wrapper.c
 135 @@ -0,0 +1,109 @@
 136 +/*
 137 + * Squashfs - a compressed read only filesystem for Linux
 138 + *
 139 + * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
 140 + * Phillip Lougher <phillip@lougher.demon.co.uk>
 141 + *
 142 + * This program is free software; you can redistribute it and/or
 143 + * modify it under the terms of the GNU General Public License
 144 + * as published by the Free Software Foundation; either version 2,
 145 + * or (at your option) any later version.
 146 + *
 147 + * This program is distributed in the hope that it will be useful,
 148 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 149 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 150 + * GNU General Public License for more details.
 151 + *
 152 + * You should have received a copy of the GNU General Public License
 153 + * along with this program; if not, write to the Free Software
 154 + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 155 + *
 156 + * zlib_wrapper.c
 157 + */
 158 +
 159 +
 160 +#include <linux/mutex.h>
 161 +#include <linux/buffer_head.h>
 162 +#include <linux/zlib.h>
 163 +
 164 +#include "squashfs_fs.h"
 165 +#include "squashfs_fs_sb.h"
 166 +#include "squashfs_fs_i.h"
 167 +#include "squashfs.h"
 168 +
 169 +int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 170 +       struct buffer_head **bh, int b, int offset, int length, int srclength,
 171 +       int pages)
 172 +{
 173 +       int zlib_err = 0, zlib_init = 0;
 174 +       int avail, bytes, k = 0, page = 0;
 175 +
 176 +       mutex_lock(&msblk->read_data_mutex);
 177 +
 178 +       msblk->stream.avail_out = 0;
 179 +       msblk->stream.avail_in = 0;
 180 +
 181 +       bytes = length;
 182 +       do {
 183 +               if (msblk->stream.avail_in == 0 && k < b) {
 184 +                       avail = min(bytes, msblk->devblksize - offset);
 185 +                       bytes -= avail;
 186 +                       wait_on_buffer(bh[k]);
 187 +                       if (!buffer_uptodate(bh[k]))
 188 +                               goto release_mutex;
 189 +
 190 +                       if (avail == 0) {
 191 +                               offset = 0;
 192 +                               put_bh(bh[k++]);
 193 +                               continue;
 194 +                       }
 195 +
 196 +                       msblk->stream.next_in = bh[k]->b_data + offset;
 197 +                       msblk->stream.avail_in = avail;
 198 +                       offset = 0;
 199 +               }
 200 +
 201 +               if (msblk->stream.avail_out == 0 && page < pages) {
 202 +                       msblk->stream.next_out = buffer[page++];
 203 +                       msblk->stream.avail_out = PAGE_CACHE_SIZE;
 204 +               }
 205 +
 206 +               if (!zlib_init) {
 207 +                       zlib_err = zlib_inflateInit(&msblk->stream);
 208 +                       if (zlib_err != Z_OK) {
 209 +                               ERROR("zlib_inflateInit returned unexpected "
 210 +                                       "result 0x%x, srclength %d\n",
 211 +                                       zlib_err, srclength);
 212 +                               goto release_mutex;
 213 +                       }
 214 +                       zlib_init = 1;
 215 +               }
 216 +
 217 +               zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH);
 218 +
 219 +               if (msblk->stream.avail_in == 0 && k < b)
 220 +                       put_bh(bh[k++]);
 221 +       } while (zlib_err == Z_OK);
 222 +
 223 +       if (zlib_err != Z_STREAM_END) {
 224 +               ERROR("zlib_inflate error, data probably corrupt\n");
 225 +               goto release_mutex;
 226 +       }
 227 +
 228 +       zlib_err = zlib_inflateEnd(&msblk->stream);
 229 +       if (zlib_err != Z_OK) {
 230 +               ERROR("zlib_inflate error, data probably corrupt\n");
 231 +               goto release_mutex;
 232 +       }
 233 +
 234 +       mutex_unlock(&msblk->read_data_mutex);
 235 +       return msblk->stream.total_out;
 236 +
 237 +release_mutex:
 238 +       mutex_unlock(&msblk->read_data_mutex);
 239 +
 240 +       for (; k < b; k++)
 241 +               put_bh(bh[k]);
 242 +
 243 +       return -EIO;
 244 +}