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

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Tao Ma <boyu.mt@taobao.com>

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@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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;