+++ /dev/null
---- a/stage2/fsys_ext2fs.c
-+++ b/stage2/fsys_ext2fs.c
-@@ -51,6 +51,9 @@ typedef unsigned int __u32;
- #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
- #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
-
-+/* Inode flags */
-+#define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */
-+
- /* include/linux/ext2_fs.h */
- struct ext2_super_block
- {
-@@ -191,6 +194,42 @@ struct ext2_dir_entry
- #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \
- ~EXT2_DIR_ROUND)
-
-+/* linux/ext4_fs_extents.h */
-+/*
-+ * This is the extent on-disk structure.
-+ * It's used at the bottom of the tree.
-+ */
-+struct ext4_extent {
-+ __u32 ee_block; /* first logical block extent covers */
-+ __u16 ee_len; /* number of blocks covered by extent */
-+ __u16 ee_start_hi; /* high 16 bits of physical block */
-+ __u32 ee_start; /* low 32 bits of physical block */
-+};
-+
-+/*
-+ * This is index on-disk structure.
-+ * It's used at all the levels except the bottom.
-+ */
-+struct ext4_extent_idx {
-+ __u32 ei_block; /* index covers logical blocks from 'block' */
-+ __u32 ei_leaf; /* pointer to the physical block of the next *
-+ * level. leaf or next index could be there */
-+ __u16 ei_leaf_hi; /* high 16 bits of physical block */
-+ __u16 ei_unused;
-+};
-+
-+/*
-+ * Each block (leaves and indexes), even inode-stored has header.
-+ */
-+struct ext4_extent_header {
-+ __u16 eh_magic; /* probably will support different formats */
-+ __u16 eh_entries; /* number of valid entries */
-+ __u16 eh_max; /* capacity of store in entries */
-+ __u16 eh_depth; /* has tree real underlying blocks? */
-+ __u32 eh_generation; /* generation of the tree */
-+};
-+
-+#define EXT4_EXT_MAGIC 0xf30a
-
- /* ext2/super.c */
- #define log2(n) ffz(~(n))
-@@ -279,6 +318,27 @@ ext2_rdfsb (int fsblock, int buffer)
- EXT2_BLOCK_SIZE (SUPERBLOCK), (char *) buffer);
- }
-
-+/* Walk through extents index tree to find the good leaf */
-+static struct ext4_extent_header *
-+ext4_recurse_extent_index(struct ext4_extent_header *extent_block, int logical_block)
-+{
-+ int i;
-+ struct ext4_extent_idx *index = (struct ext4_extent_idx *) (extent_block + 1);
-+ if (extent_block->eh_magic != EXT4_EXT_MAGIC)
-+ return NULL;
-+ if (extent_block->eh_depth == 0)
-+ return extent_block;
-+ for (i = 0; i < extent_block->eh_entries; i++)
-+ {
-+ if (logical_block < index[i].ei_block)
-+ break;
-+ }
-+ if (i == 0 || !ext2_rdfsb(index[i-1].ei_leaf, DATABLOCK1))
-+ return NULL;
-+ return (ext4_recurse_extent_index((struct ext4_extent_header *) DATABLOCK1, logical_block));
-+}
-+
-+
- /* from
- ext2/inode.c:ext2_bmap()
- */
-@@ -287,7 +347,6 @@ ext2_rdfsb (int fsblock, int buffer)
- static int
- ext2fs_block_map (int logical_block)
- {
--
- #ifdef E2DEBUG
- unsigned char *i;
- for (i = (unsigned char *) INODE;
-@@ -308,82 +367,106 @@ ext2fs_block_map (int logical_block)
- printf ("logical block %d\n", logical_block);
- #endif /* E2DEBUG */
-
-- /* if it is directly pointed to by the inode, return that physical addr */
-- if (logical_block < EXT2_NDIR_BLOCKS)
-+ if (!(INODE->i_flags & EXT4_EXTENTS_FL))
- {
--#ifdef E2DEBUG
-- printf ("returning %d\n", (unsigned char *) (INODE->i_block[logical_block]));
-- printf ("returning %d\n", INODE->i_block[logical_block]);
--#endif /* E2DEBUG */
-- return INODE->i_block[logical_block];
-- }
-- /* else */
-- logical_block -= EXT2_NDIR_BLOCKS;
-- /* try the indirect block */
-- if (logical_block < EXT2_ADDR_PER_BLOCK (SUPERBLOCK))
-- {
-- if (mapblock1 != 1
-- && !ext2_rdfsb (INODE->i_block[EXT2_IND_BLOCK], DATABLOCK1))
-- {
-- errnum = ERR_FSYS_CORRUPT;
-- return -1;
-- }
-- mapblock1 = 1;
-- return ((__u32 *) DATABLOCK1)[logical_block];
-- }
-- /* else */
-- logical_block -= EXT2_ADDR_PER_BLOCK (SUPERBLOCK);
-- /* now try the double indirect block */
-- if (logical_block < (1 << (EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK) * 2)))
-- {
-- int bnum;
-- if (mapblock1 != 2
-- && !ext2_rdfsb (INODE->i_block[EXT2_DIND_BLOCK], DATABLOCK1))
-- {
-- errnum = ERR_FSYS_CORRUPT;
-- return -1;
-- }
-- mapblock1 = 2;
-- if ((bnum = (((__u32 *) DATABLOCK1)
-- [logical_block >> EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK)]))
-- != mapblock2
-- && !ext2_rdfsb (bnum, DATABLOCK2))
-- {
-- errnum = ERR_FSYS_CORRUPT;
-- return -1;
-- }
-- mapblock2 = bnum;
-+ /* if it is directly pointed to by the inode, return that physical addr */
-+ if (logical_block < EXT2_NDIR_BLOCKS)
-+ {
-+#ifdef E2DEBUG
-+ printf ("returning %d\n", (unsigned char *) (INODE->i_block[logical_block]));
-+ printf ("returning %d\n", INODE->i_block[logical_block]);
-+#endif /* E2DEBUG */
-+ return INODE->i_block[logical_block];
-+ }
-+ /* else */
-+ logical_block -= EXT2_NDIR_BLOCKS;
-+ /* try the indirect block */
-+ if (logical_block < EXT2_ADDR_PER_BLOCK (SUPERBLOCK))
-+ {
-+ if (mapblock1 != 1 && !ext2_rdfsb (INODE->i_block[EXT2_IND_BLOCK], DATABLOCK1))
-+ {
-+ errnum = ERR_FSYS_CORRUPT;
-+ return -1;
-+ }
-+ mapblock1 = 1;
-+ return ((__u32 *) DATABLOCK1)[logical_block];
-+ }
-+ /* else */
-+ logical_block -= EXT2_ADDR_PER_BLOCK (SUPERBLOCK);
-+ /* now try the double indirect block */
-+ if (logical_block < (1 << (EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK) * 2)))
-+ {
-+ int bnum;
-+ if (mapblock1 != 2 && !ext2_rdfsb (INODE->i_block[EXT2_DIND_BLOCK], DATABLOCK1))
-+ {
-+ errnum = ERR_FSYS_CORRUPT;
-+ return -1;
-+ }
-+ mapblock1 = 2;
-+ if ((bnum = (((__u32 *) DATABLOCK1)
-+ [logical_block >> EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK)]))
-+ != mapblock2
-+ && !ext2_rdfsb (bnum, DATABLOCK2))
-+ {
-+ errnum = ERR_FSYS_CORRUPT;
-+ return -1;
-+ }
-+ mapblock2 = bnum;
-+ return ((__u32 *) DATABLOCK2)
-+ [logical_block & (EXT2_ADDR_PER_BLOCK (SUPERBLOCK) - 1)];
-+ }
-+ /* else */
-+ mapblock2 = -1;
-+ logical_block -= (1 << (EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK) * 2));
-+ if (mapblock1 != 3
-+ && !ext2_rdfsb (INODE->i_block[EXT2_TIND_BLOCK], DATABLOCK1))
-+ {
-+ errnum = ERR_FSYS_CORRUPT;
-+ return -1;
-+ }
-+ mapblock1 = 3;
-+ if (!ext2_rdfsb (((__u32 *) DATABLOCK1)
-+ [logical_block >> (EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK)
-+ * 2)],
-+ DATABLOCK2))
-+ {
-+ errnum = ERR_FSYS_CORRUPT;
-+ return -1;
-+ }
-+ if (!ext2_rdfsb (((__u32 *) DATABLOCK2)
-+ [(logical_block >> EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK))
-+ & (EXT2_ADDR_PER_BLOCK (SUPERBLOCK) - 1)],
-+ DATABLOCK2))
-+ {
-+ errnum = ERR_FSYS_CORRUPT;
-+ return -1;
-+ }
-+
- return ((__u32 *) DATABLOCK2)
-- [logical_block & (EXT2_ADDR_PER_BLOCK (SUPERBLOCK) - 1)];
-+ [logical_block & (EXT2_ADDR_PER_BLOCK (SUPERBLOCK) - 1)];
- }
-- /* else */
-- mapblock2 = -1;
-- logical_block -= (1 << (EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK) * 2));
-- if (mapblock1 != 3
-- && !ext2_rdfsb (INODE->i_block[EXT2_TIND_BLOCK], DATABLOCK1))
-- {
-- errnum = ERR_FSYS_CORRUPT;
-- return -1;
-- }
-- mapblock1 = 3;
-- if (!ext2_rdfsb (((__u32 *) DATABLOCK1)
-- [logical_block >> (EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK)
-- * 2)],
-- DATABLOCK2))
-- {
-- errnum = ERR_FSYS_CORRUPT;
-- return -1;
-- }
-- if (!ext2_rdfsb (((__u32 *) DATABLOCK2)
-- [(logical_block >> EXT2_ADDR_PER_BLOCK_BITS (SUPERBLOCK))
-- & (EXT2_ADDR_PER_BLOCK (SUPERBLOCK) - 1)],
-- DATABLOCK2))
-+ /* inode is in extents format */
-+ else
- {
-+ int i;
-+ struct ext4_extent_header *extent_hdr =
-+ ext4_recurse_extent_index((struct ext4_extent_header *) INODE->i_block, logical_block);
-+ struct ext4_extent *extent = (struct ext4_extent *) (extent_hdr + 1);
-+ if ( extent_hdr == NULL || extent_hdr->eh_magic != EXT4_EXT_MAGIC)
-+ {
-+ errnum = ERR_FSYS_CORRUPT;
-+ return -1;
-+ }
-+ for (i = 0; i<extent_hdr->eh_entries; i++)
-+ {
-+ if (extent[i].ee_block <= logical_block && logical_block < extent[i].ee_block + extent[i].ee_len && !(extent[i].ee_len>>15))
-+ return (logical_block - extent[i].ee_block + extent[i].ee_start);
-+ }
-+ /* We should not arrive here */
-+
- errnum = ERR_FSYS_CORRUPT;
- return -1;
- }
-- return ((__u32 *) DATABLOCK2)
-- [logical_block & (EXT2_ADDR_PER_BLOCK (SUPERBLOCK) - 1)];
- }
-
- /* preconditions: all preconds of ext2fs_block_map */
projects / openwrt.git / blobdiff