Re: [PATCH 1/2] xfs: fix deadlock retry tracepoint arguments

[Brian Foster <bfoster@redhat.com>]

On Wed, May 12, 2021 at 06:01:34PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> sc->ip is the inode that's being scrubbed, which means that it's not set
> for scrub types that don't involve inodes.  If one of those scrubbers
> (e.g. inode btrees) returns EDEADLOCK, we'll trip over the null pointer.
> Fix that by reporting either the file being examined or the file that
> was used to call scrub.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/scrub/common.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> 
> diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
> index aa874607618a..be38c960da85 100644
> --- a/fs/xfs/scrub/common.c
> +++ b/fs/xfs/scrub/common.c
> @@ -74,7 +74,9 @@ __xchk_process_error(
>  		return true;
>  	case -EDEADLOCK:
>  		/* Used to restart an op with deadlock avoidance. */
> -		trace_xchk_deadlock_retry(sc->ip, sc->sm, *error);
> +		trace_xchk_deadlock_retry(
> +				sc->ip ? sc->ip : XFS_I(file_inode(sc->file)),
> +				sc->sm, *error);
>  		break;
>  	case -EFSBADCRC:
>  	case -EFSCORRUPTED:
>