Re: [PATCH] xfs: log proper length of superblock

[Eric Sandeen <sandeen@sandeen.net>]

On 9/23/19 4:18 PM, Eric Sandeen wrote:
> xfs_trans_log_buf takes first byte, last byte as args.  In this
> case, it should be from 0 to sizeof() - 1.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>

if you want, you could put a 

Fixes: 4d11a40239405 ("xfs: remove bitfield based superblock updates")

on this, I guess it was technically a regression in v4.0, even
if it has no net effect like last time...

-Eric

> ---
> 
> I should have audited everything when I sent the last patch for
> this type of error.  hch suggested changing the interface but it's
> all pretty grotty and I'm hesitant for now.
> 
> I think maybe a new/separate function to take start, len might
> make sense so that not every caller needs to be munged into a new
> format, because some of the existing callers would then become more
> complex...
> 
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index a08dd8f40346..ac6cdca63e15 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -928,7 +928,7 @@ xfs_log_sb(
>  
>  	xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
>  	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
> -	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb));
> +	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb) - 1);
>  }
>  
>  /*
>