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authorDarrick J. Wong <djwong@us.ibm.com>2012-04-29 18:33:10 -0400
committerTheodore Ts'o <tytso@mit.edu>2012-04-29 18:33:10 -0400
commit41a246d1ff75a95d2be3191ca6e6db139dc0f430 (patch)
tree0b5150f476dd69726ffe7ea1ba83832c42b441be /fs/ext4/ialloc.c
parent814525f4df50a196464ce2c7abe91f693203060f (diff)
ext4: calculate and verify checksums for inode bitmaps
Compute and verify the checksum of the inode bitmap; the checkum is stored in the block group descriptor. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ialloc.c')
-rw-r--r--fs/ext4/ialloc.c34
1 files changed, 29 insertions, 5 deletions
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 8207dfab268..fb897ec183c 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -82,12 +82,17 @@ static unsigned ext4_init_inode_bitmap(struct super_block *sb,
ext4_free_inodes_set(sb, gdp, 0);
ext4_itable_unused_set(sb, gdp, 0);
memset(bh->b_data, 0xff, sb->s_blocksize);
+ ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
+ EXT4_INODES_PER_GROUP(sb) / 8);
return 0;
}
memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8);
ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
bh->b_data);
+ ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh,
+ EXT4_INODES_PER_GROUP(sb) / 8);
+ gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
return EXT4_INODES_PER_GROUP(sb);
}
@@ -128,12 +133,12 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
return NULL;
}
if (bitmap_uptodate(bh))
- return bh;
+ goto verify;
lock_buffer(bh);
if (bitmap_uptodate(bh)) {
unlock_buffer(bh);
- return bh;
+ goto verify;
}
ext4_lock_group(sb, block_group);
@@ -141,6 +146,7 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
ext4_init_inode_bitmap(sb, bh, block_group, desc);
set_bitmap_uptodate(bh);
set_buffer_uptodate(bh);
+ set_buffer_verified(bh);
ext4_unlock_group(sb, block_group);
unlock_buffer(bh);
return bh;
@@ -154,7 +160,7 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
*/
set_bitmap_uptodate(bh);
unlock_buffer(bh);
- return bh;
+ goto verify;
}
/*
* submit the buffer_head for reading
@@ -171,6 +177,20 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
block_group, bitmap_blk);
return NULL;
}
+
+verify:
+ ext4_lock_group(sb, block_group);
+ if (!buffer_verified(bh) &&
+ !ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
+ EXT4_INODES_PER_GROUP(sb) / 8)) {
+ ext4_unlock_group(sb, block_group);
+ put_bh(bh);
+ ext4_error(sb, "Corrupt inode bitmap - block_group = %u, "
+ "inode_bitmap = %llu", block_group, bitmap_blk);
+ return NULL;
+ }
+ ext4_unlock_group(sb, block_group);
+ set_buffer_verified(bh);
return bh;
}
@@ -276,6 +296,8 @@ void ext4_free_inode(handle_t *handle, struct inode *inode)
ext4_used_dirs_set(sb, gdp, count);
percpu_counter_dec(&sbi->s_dirs_counter);
}
+ ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
+ EXT4_INODES_PER_GROUP(sb) / 8);
gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
ext4_unlock_group(sb, block_group);
@@ -751,7 +773,7 @@ got:
goto fail;
/* Update the relevant bg descriptor fields */
- if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+ if (ext4_has_group_desc_csum(sb)) {
int free;
struct ext4_group_info *grp = ext4_get_group_info(sb, group);
@@ -782,7 +804,9 @@ got:
atomic_inc(&sbi->s_flex_groups[f].used_dirs);
}
}
- if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
+ if (ext4_has_group_desc_csum(sb)) {
+ ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh,
+ EXT4_INODES_PER_GROUP(sb) / 8);
gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
ext4_unlock_group(sb, group);
}