ext4: Checksum the block bitmap properly with bigalloc enabled

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>
Cc: stable@vger.kernel.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 78971cfd9c7f..3c20de1d59d0 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1882,10 +1882,10 @@ 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 fa36372f3fdf..4facdd29a350 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -762,9 +762,7 @@ 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 a415465f97a0..eb1e385d8080 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2805,8 +2805,7 @@ 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);
@@ -4666,8 +4665,7 @@ 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);
@@ -4811,8 +4809,7 @@ 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 7a75e1086961..47bf06a2765d 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1212,8 +1212,7 @@ 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;