Re: [PATCH 12/12] xfs: random buffer write failure errortag

[Allison Collins <allison.henderson@xxxxxxxxxx>]

On 4/17/20 8:08 AM, Brian Foster wrote:
> Introduce an error tag to randomly fail async buffer writes. This is
> primarily to facilitate testing of the XFS error configuration
> mechanism.
>
> Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
Ok, I think it looks ok:
Reviewed-by: Allison Collins <allison.henderson@xxxxxxxxxx>

> ---
>   fs/xfs/libxfs/xfs_errortag.h | 4 +++-
>   fs/xfs/xfs_buf.c             | 6 ++++++
>   fs/xfs/xfs_error.c           | 3 +++
>   3 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/fs/xfs/libxfs/xfs_errortag.h b/fs/xfs/libxfs/xfs_errortag.h
> index 79e6c4fb1d8a..2486dab19023 100644
> --- a/fs/xfs/libxfs/xfs_errortag.h
> +++ b/fs/xfs/libxfs/xfs_errortag.h
> @@ -55,7 +55,8 @@
>   #define XFS_ERRTAG_FORCE_SCRUB_REPAIR			32
>   #define XFS_ERRTAG_FORCE_SUMMARY_RECALC			33
>   #define XFS_ERRTAG_IUNLINK_FALLBACK			34
> -#define XFS_ERRTAG_MAX					35
> +#define XFS_ERRTAG_BUF_IOERROR				35
> +#define XFS_ERRTAG_MAX					36
>   
>   /*
>    * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
> @@ -95,5 +96,6 @@
>   #define XFS_RANDOM_FORCE_SCRUB_REPAIR			1
>   #define XFS_RANDOM_FORCE_SUMMARY_RECALC			1
>   #define XFS_RANDOM_IUNLINK_FALLBACK			(XFS_RANDOM_DEFAULT/10)
> +#define XFS_RANDOM_BUF_IOERROR				XFS_RANDOM_DEFAULT
>   
>   #endif /* __XFS_ERRORTAG_H_ */
> diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
> index 5120fed06075..a305db779156 100644
> --- a/fs/xfs/xfs_buf.c
> +++ b/fs/xfs/xfs_buf.c
> @@ -1289,6 +1289,12 @@ xfs_buf_bio_end_io(
>   	struct bio		*bio)
>   {
>   	struct xfs_buf		*bp = (struct xfs_buf *)bio->bi_private;
> +	struct xfs_mount	*mp = bp->b_mount;
> +
> +	if (!bio->bi_status &&
> +	    (bp->b_flags & XBF_WRITE) && (bp->b_flags & XBF_ASYNC) &&
> +	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BUF_IOERROR))
> +		bio->bi_status = errno_to_blk_status(-EIO);
>   
>   	/*
>   	 * don't overwrite existing errors - otherwise we can lose errors on
> diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
> index a21e9cc6516a..7f6e20899473 100644
> --- a/fs/xfs/xfs_error.c
> +++ b/fs/xfs/xfs_error.c
> @@ -53,6 +53,7 @@ static unsigned int xfs_errortag_random_default[] = {
>   	XFS_RANDOM_FORCE_SCRUB_REPAIR,
>   	XFS_RANDOM_FORCE_SUMMARY_RECALC,
>   	XFS_RANDOM_IUNLINK_FALLBACK,
> +	XFS_RANDOM_BUF_IOERROR,
>   };
>   
>   struct xfs_errortag_attr {
> @@ -162,6 +163,7 @@ XFS_ERRORTAG_ATTR_RW(buf_lru_ref,	XFS_ERRTAG_BUF_LRU_REF);
>   XFS_ERRORTAG_ATTR_RW(force_repair,	XFS_ERRTAG_FORCE_SCRUB_REPAIR);
>   XFS_ERRORTAG_ATTR_RW(bad_summary,	XFS_ERRTAG_FORCE_SUMMARY_RECALC);
>   XFS_ERRORTAG_ATTR_RW(iunlink_fallback,	XFS_ERRTAG_IUNLINK_FALLBACK);
> +XFS_ERRORTAG_ATTR_RW(buf_ioerror,	XFS_ERRTAG_BUF_IOERROR);
>   
>   static struct attribute *xfs_errortag_attrs[] = {
>   	XFS_ERRORTAG_ATTR_LIST(noerror),
> @@ -199,6 +201,7 @@ static struct attribute *xfs_errortag_attrs[] = {
>   	XFS_ERRORTAG_ATTR_LIST(force_repair),
>   	XFS_ERRORTAG_ATTR_LIST(bad_summary),
>   	XFS_ERRORTAG_ATTR_LIST(iunlink_fallback),
> +	XFS_ERRORTAG_ATTR_LIST(buf_ioerror),
>   	NULL,
>   };
>