[ 02/85] ext4: Checksum the block bitmap properly with bigalloc enabled

From: Greg Kroah-Hartman
Date: Thu Oct 25 2012 - 20:07:14 EST

3.6-stable review patch. If anyone has any objections, please let me know.

------------------

From: Tao Ma <boyu.mt@xxxxxxxxxx>

commit 79f1ba49569e5aec919b653c55b03274c2331701 upstream.

In mke2fs, we only checksum the whole bitmap block and it is right.
While in the kernel, we use EXT4_BLOCKS_PER_GROUP to indicate the
size of the checksumed bitmap which is wrong when we enable bigalloc.
The right size should be EXT4_CLUSTERS_PER_GROUP and this patch fixes
it.

Also as every caller of ext4_block_bitmap_csum_set and
ext4_block_bitmap_csum_verify pass in EXT4_BLOCKS_PER_GROUP(sb)/8,
we'd better removes this parameter and sets it in the function itself.

Signed-off-by: Tao Ma <boyu.mt@xxxxxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Reviewed-by: Lukas Czerner <lczerner@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/ext4/balloc.c | 8 +++-----
fs/ext4/bitmap.c | 6 ++++--
fs/ext4/ext4.h | 4 ++--
fs/ext4/ialloc.c | 4 +---
fs/ext4/mballoc.c | 9 +++------
fs/ext4/resize.c | 3 +--
6 files changed, 14 insertions(+), 20 deletions(-)

--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -174,8 +174,7 @@ void ext4_init_block_bitmap(struct super
ext4_free_inodes_set(sb, gdp, 0);
ext4_itable_unused_set(sb, gdp, 0);
memset(bh->b_data, 0xff, sb->s_blocksize);
- ext4_block_bitmap_csum_set(sb, block_group, gdp, bh,
- EXT4_BLOCKS_PER_GROUP(sb) / 8);
+ ext4_block_bitmap_csum_set(sb, block_group, gdp, bh);
return;
}
memset(bh->b_data, 0, sb->s_blocksize);
@@ -212,8 +211,7 @@ void ext4_init_block_bitmap(struct super
*/
ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group),
sb->s_blocksize * 8, bh->b_data);
- ext4_block_bitmap_csum_set(sb, block_group, gdp, bh,
- EXT4_BLOCKS_PER_GROUP(sb) / 8);
+ ext4_block_bitmap_csum_set(sb, block_group, gdp, bh);
ext4_group_desc_csum_set(sb, block_group, gdp);
}

@@ -350,7 +348,7 @@ void ext4_validate_block_bitmap(struct s
return;
}
if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
- desc, bh, EXT4_BLOCKS_PER_GROUP(sb) / 8))) {
+ desc, bh))) {
ext4_unlock_group(sb, block_group);
ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
return;
--- a/fs/ext4/bitmap.c
+++ b/fs/ext4/bitmap.c
@@ -58,11 +58,12 @@ void ext4_inode_bitmap_csum_set(struct s

int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
struct ext4_group_desc *gdp,
- struct buffer_head *bh, int sz)
+ struct buffer_head *bh)
{
__u32 hi;
__u32 provided, calculated;
struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;

if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
@@ -84,8 +85,9 @@ int ext4_block_bitmap_csum_verify(struct

void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
struct ext4_group_desc *gdp,
- struct buffer_head *bh, int sz)
+ struct buffer_head *bh)
{
+ int sz = EXT4_CLUSTERS_PER_GROUP(sb) / 8;
__u32 csum;
struct ext4_sb_info *sbi = EXT4_SB(sb);

--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1867,10 +1867,10 @@ int ext4_inode_bitmap_csum_verify(struct
struct buffer_head *bh, int sz);
void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
struct ext4_group_desc *gdp,
- struct buffer_head *bh, int sz);
+ struct buffer_head *bh);
int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
struct ext4_group_desc *gdp,
- struct buffer_head *bh, int sz);
+ struct buffer_head *bh);

/* balloc.c */
extern void ext4_validate_block_bitmap(struct super_block *sb,
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -753,9 +753,7 @@ got:
ext4_free_group_clusters_set(sb, gdp,
ext4_free_clusters_after_init(sb, group, gdp));
ext4_block_bitmap_csum_set(sb, group, gdp,
- block_bitmap_bh,
- EXT4_BLOCKS_PER_GROUP(sb) /
- 8);
+ block_bitmap_bh);
ext4_group_desc_csum_set(sb, group, gdp);
}
ext4_unlock_group(sb, group);
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2804,8 +2804,7 @@ ext4_mb_mark_diskspace_used(struct ext4_
}
len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len;
ext4_free_group_clusters_set(sb, gdp, len);
- ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh,
- EXT4_BLOCKS_PER_GROUP(sb) / 8);
+ ext4_block_bitmap_csum_set(sb, ac->ac_b_ex.fe_group, gdp, bitmap_bh);
ext4_group_desc_csum_set(sb, ac->ac_b_ex.fe_group, gdp);

ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
@@ -4664,8 +4663,7 @@ do_more:

ret = ext4_free_group_clusters(sb, gdp) + count_clusters;
ext4_free_group_clusters_set(sb, gdp, ret);
- ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh,
- EXT4_BLOCKS_PER_GROUP(sb) / 8);
+ ext4_block_bitmap_csum_set(sb, block_group, gdp, bitmap_bh);
ext4_group_desc_csum_set(sb, block_group, gdp);
ext4_unlock_group(sb, block_group);
percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);
@@ -4809,8 +4807,7 @@ int ext4_group_add_blocks(handle_t *hand
mb_free_blocks(NULL, &e4b, bit, count);
blk_free_count = blocks_freed + ext4_free_group_clusters(sb, desc);
ext4_free_group_clusters_set(sb, desc, blk_free_count);
- ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh,
- EXT4_BLOCKS_PER_GROUP(sb) / 8);
+ ext4_block_bitmap_csum_set(sb, block_group, desc, bitmap_bh);
ext4_group_desc_csum_set(sb, block_group, desc);
ext4_unlock_group(sb, block_group);
percpu_counter_add(&sbi->s_freeclusters_counter,
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1121,8 +1121,7 @@ static int ext4_set_bitmap_checksums(str
bh = ext4_get_bitmap(sb, group_data->block_bitmap);
if (!bh)
return -EIO;
- ext4_block_bitmap_csum_set(sb, group, gdp, bh,
- EXT4_BLOCKS_PER_GROUP(sb) / 8);
+ ext4_block_bitmap_csum_set(sb, group, gdp, bh);
brelse(bh);

return 0;


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