ext4: Checksum the block bitmap properly with bigalloc enabled

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>

6 files changed, 14 insertions, 20 deletions

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 1b5089067d01..cf1821784a16 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -174,8 +174,7 @@ void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
 		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_block *sb, struct buffer_head *bh,
 	 */
 	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 super_block *sb,
 		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;
diff --git a/fs/ext4/bitmap.c b/fs/ext4/bitmap.c
index 5c2d1813ebe9..3285aa5a706a 100644
--- a/fs/ext4/bitmap.c
+++ b/fs/ext4/bitmap.c
@@ -58,11 +58,12 @@ void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
 
 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 super_block *sb, ext4_group_t group,
 
 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);
 
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index c3411d4ce2da..5c69f2b32b1c 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1867,10 +1867,10 @@ int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
 				  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,
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 26154b81b836..8ce0076c3152 100644
--- 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);
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 8eae94771c45..e3feae5567ab 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2804,8 +2804,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 	}
 	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 *handle, struct super_block *sb,
 	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,
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 0be1789ebc3b..71241bc0eea6 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1121,8 +1121,7 @@ static int ext4_set_bitmap_checksums(struct super_block *sb,
 	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;