Re: [PATCH 21/22] xfs: add error injection for lazy bounce buffering

["Darrick J. Wong" <djwong@kernel.org>]

On Thu, Jul 23, 2026 at 04:49:46PM +0200, Christoph Hellwig wrote:
> Add an error injection know to exercise the lazy bounce buffering
> code path, i.e. to inject direct I/O re-read using the bounce buffer.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

LGTM
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/xfs/libxfs/xfs_errortag.h | 6 ++++--
>  fs/xfs/xfs_ioend.c           | 5 ++++-
>  2 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_errortag.h b/fs/xfs/libxfs/xfs_errortag.h
> index 6de207fed2d8..2dc441da0333 100644
> --- a/fs/xfs/libxfs/xfs_errortag.h
> +++ b/fs/xfs/libxfs/xfs_errortag.h
> @@ -75,7 +75,8 @@
>  #define XFS_ERRTAG_METAFILE_RESV_CRITICAL		45
>  #define XFS_ERRTAG_FORCE_ZERO_RANGE			46
>  #define XFS_ERRTAG_ZONE_RESET				47
> -#define XFS_ERRTAG_MAX					48
> +#define XFS_ERRTAG_BOUNCE_REREAD			48
> +#define XFS_ERRTAG_MAX					49
>  
>  /*
>   * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
> @@ -137,7 +138,8 @@ XFS_ERRTAG(WRITE_DELAY_MS,	write_delay_ms,		3000) \
>  XFS_ERRTAG(EXCHMAPS_FINISH_ONE,	exchmaps_finish_one,	1) \
>  XFS_ERRTAG(METAFILE_RESV_CRITICAL, metafile_resv_crit,	4) \
>  XFS_ERRTAG(FORCE_ZERO_RANGE,	force_zero_range,	4) \
> -XFS_ERRTAG(ZONE_RESET,		zone_reset,		1)
> +XFS_ERRTAG(ZONE_RESET,		zone_reset,		1)  \
> +XFS_ERRTAG(BOUNCE_REREAD,	bounce_reread,		XFS_RANDOM_DEFAULT)
>  #endif /* XFS_ERRTAG */
>  
>  #endif /* __XFS_ERRORTAG_H_ */
> diff --git a/fs/xfs/xfs_ioend.c b/fs/xfs/xfs_ioend.c
> index 94a81fb679ed..641f0d881b07 100644
> --- a/fs/xfs/xfs_ioend.c
> +++ b/fs/xfs/xfs_ioend.c
> @@ -16,6 +16,8 @@
>  #include "xfs_reflink.h"
>  #include "xfs_zone_alloc.h"
>  #include "xfs_ioend.h"
> +#include "xfs_error.h"
> +#include "xfs_errortag.h"
>  #include <linux/bio-integrity.h>
>  
>  static void
> @@ -103,7 +105,8 @@ xfs_end_io_read(
>  			 * but right now we can't distinguish them from other
>  			 * (i.e, reftag) errors.
>  			 */
> -			if (error) {
> +			if (error ||
> +			    XFS_TEST_ERROR(mp, XFS_ERRTAG_BOUNCE_REREAD)) {
>  				xfs_read_bounce_and_resubmit(ioend);
>  				return;
>  			}
> -- 
> 2.53.0
> 
>