ext4: fix uninit block bitmap initialization when s_meta_first_bg is non-zero
The number of old-style block group descriptor blocks is
s_meta_first_bg when the meta_bg feature flag is set.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 1d04189..f3032c9 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -761,7 +761,13 @@
static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb,
ext4_group_t group)
{
- return ext4_bg_has_super(sb, group) ? EXT4_SB(sb)->s_gdb_count : 0;
+ if (!ext4_bg_has_super(sb, group))
+ return 0;
+
+ if (EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG))
+ return le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
+ else
+ return EXT4_SB(sb)->s_gdb_count;
}
/**