ACK: [SRU][Bionic][PATCH 1/1] UBUNTU: SAUCE: ext4: fix ext4_validate_inode_bitmap: comm stress-ng: Corrupt inode bitmap

[Colin Ian King]

On 10/07/18 23:11, Kamal Mostafa wrote:
> From: "Theodore Y. Ts'o" <tytso at mit.edu>
> 
> BugLink: http://bugs.launchpad.net/bugs/1780137
> 
> Fix regression triggered by the stress-ng[*] "chdir" test, with LKML test
> patch.
> 
> Regression observed on some arm64 server platforms:
> 
>     EXT4-fs error (device sda1): ext4_validate_inode_bitmap:99: comm stress-ng: Corrupt inode bitmap
> 
> Reference: https://lkml.org/lkml/2018/7/7/2
> 
> Reported-by: dann frazier <dann.frazier at canonical.com>
> Tested-by: dann frazier <dann.frazier at canonical.com>
> Fixes: 044e6e3d74a3 ext4: don't update checksum of new initialized bitmaps
> Signed-off-by: Kamal Mostafa <kamal at canonical.com>
> ---
>  fs/ext4/ialloc.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
> index 5559313..b5e2cc2 100644
> --- a/fs/ext4/ialloc.c
> +++ b/fs/ext4/ialloc.c
> @@ -91,6 +91,8 @@ static int ext4_validate_inode_bitmap(struct super_block *sb,
>  		return -EFSCORRUPTED;
>  
>  	ext4_lock_group(sb, block_group);
> +	if (buffer_verified(bh))
> +		goto verified;
>  	blk = ext4_inode_bitmap(sb, desc);
>  	if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh,
>  					   EXT4_INODES_PER_GROUP(sb) / 8)) {
> @@ -108,6 +110,7 @@ static int ext4_validate_inode_bitmap(struct super_block *sb,
>  		return -EFSBADCRC;
>  	}
>  	set_buffer_verified(bh);
> +verified:
>  	ext4_unlock_group(sb, block_group);
>  	return 0;
>  }
> 
Fixes the reported issue, can't argue with that.

Acked-by: Colin Ian King <colin.king at canonical.com>