On Tue, Jan 26, 2021 at 08:56:21PM +0800, Gao Xiang wrote:
> per-AG resv failure after fixing up freespace is hard to test in an
> effective way, so directly add an error injection path to observe
> such error handling path works as expected.
>
> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxx>
> ---
> fs/xfs/libxfs/xfs_ag.c | 5 +++++
> fs/xfs/libxfs/xfs_errortag.h | 4 +++-
> fs/xfs/xfs_error.c | 2 ++
> 3 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/fs/xfs/libxfs/xfs_ag.c b/fs/xfs/libxfs/xfs_ag.c
> index c6e68e265269..5076913c153f 100644
> --- a/fs/xfs/libxfs/xfs_ag.c
> +++ b/fs/xfs/libxfs/xfs_ag.c
> @@ -23,6 +23,7 @@
> #include "xfs_ag_resv.h"
> #include "xfs_health.h"
> #include "xfs_error.h"
> +#include "xfs_errortag.h"
> #include "xfs_bmap.h"
> #include "xfs_defer.h"
> #include "xfs_log_format.h"
> @@ -559,6 +560,10 @@ xfs_ag_shrink_space(
> be32_add_cpu(&agf->agf_length, -len);
>
> err2 = xfs_ag_resv_init(agibp->b_pag, *tpp);
> +
> + if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_SHRINKFS_AG_RESV_FAIL))
> + err2 = -ENOSPC;
> +
Seems reasonable, but I feel like this could be broadened to serve as a
generic perag reservation error tag. I suppose we might not be able to
use it on a clean mount, but perhaps it could be reused for growfs and
remount. Hm?
Brian
> if (err2) {
> be32_add_cpu(&agi->agi_length, len);
> be32_add_cpu(&agf->agf_length, len);
> diff --git a/fs/xfs/libxfs/xfs_errortag.h b/fs/xfs/libxfs/xfs_errortag.h
> index 6ca9084b6934..5fd71a930b68 100644
> --- a/fs/xfs/libxfs/xfs_errortag.h
> +++ b/fs/xfs/libxfs/xfs_errortag.h
> @@ -40,6 +40,7 @@
> #define XFS_ERRTAG_REFCOUNT_FINISH_ONE 25
> #define XFS_ERRTAG_BMAP_FINISH_ONE 26
> #define XFS_ERRTAG_AG_RESV_CRITICAL 27
> +
> /*
> * DEBUG mode instrumentation to test and/or trigger delayed allocation
> * block killing in the event of failed writes. When enabled, all
> @@ -58,7 +59,8 @@
> #define XFS_ERRTAG_BUF_IOERROR 35
> #define XFS_ERRTAG_REDUCE_MAX_IEXTENTS 36
> #define XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT 37
> -#define XFS_ERRTAG_MAX 38
> +#define XFS_ERRTAG_SHRINKFS_AG_RESV_FAIL 38
> +#define XFS_ERRTAG_MAX 39
>
> /*
> * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
> diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
> index 185b4915b7bf..7bae34bfddd2 100644
> --- a/fs/xfs/xfs_error.c
> +++ b/fs/xfs/xfs_error.c
> @@ -168,6 +168,7 @@ XFS_ERRORTAG_ATTR_RW(iunlink_fallback, XFS_ERRTAG_IUNLINK_FALLBACK);
> XFS_ERRORTAG_ATTR_RW(buf_ioerror, XFS_ERRTAG_BUF_IOERROR);
> XFS_ERRORTAG_ATTR_RW(reduce_max_iextents, XFS_ERRTAG_REDUCE_MAX_IEXTENTS);
> XFS_ERRORTAG_ATTR_RW(bmap_alloc_minlen_extent, XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT);
> +XFS_ERRORTAG_ATTR_RW(shrinkfs_ag_resv_fail, XFS_ERRTAG_SHRINKFS_AG_RESV_FAIL);
>
> static struct attribute *xfs_errortag_attrs[] = {
> XFS_ERRORTAG_ATTR_LIST(noerror),
> @@ -208,6 +209,7 @@ static struct attribute *xfs_errortag_attrs[] = {
> XFS_ERRORTAG_ATTR_LIST(buf_ioerror),
> XFS_ERRORTAG_ATTR_LIST(reduce_max_iextents),
> XFS_ERRORTAG_ATTR_LIST(bmap_alloc_minlen_extent),
> + XFS_ERRORTAG_ATTR_LIST(shrinkfs_ag_resv_fail),
> NULL,
> };
>
> --
> 2.27.0
>
