On Mon, Jul 26, 2021 at 05:15:41PM +0530, Chandan Babu R wrote:
> This commit adds a new error tag to allow user space tests to check if V5
> bulkstat ioctl skips reporting inodes with large extent count.
>
> Signed-off-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
Keep in mind that each of these injection knobs costs us 4 bytes per
mount. No particular objections, but I don't know how urgently we need
to do that to test a corner case...
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ---
> fs/xfs/libxfs/xfs_errortag.h | 4 +++-
> fs/xfs/xfs_error.c | 3 +++
> fs/xfs/xfs_itable.c | 9 ++++++++-
> 3 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_errortag.h b/fs/xfs/libxfs/xfs_errortag.h
> index f5fa2151e05d..b2c533153737 100644
> --- a/fs/xfs/libxfs/xfs_errortag.h
> +++ b/fs/xfs/libxfs/xfs_errortag.h
> @@ -60,7 +60,8 @@
> #define XFS_ERRTAG_BMAP_ALLOC_MINLEN_EXTENT 37
> #define XFS_ERRTAG_AG_RESV_FAIL 38
> #define XFS_ERRTAG_SWAPEXT_FINISH_ONE 39
> -#define XFS_ERRTAG_MAX 40
> +#define XFS_ERRTAG_BULKSTAT_REDUCE_MAX_IEXTENTS 40
> +#define XFS_ERRTAG_MAX 41
>
> /*
> * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
> @@ -105,5 +106,6 @@
> #define XFS_RANDOM_BMAP_ALLOC_MINLEN_EXTENT 1
> #define XFS_RANDOM_AG_RESV_FAIL 1
> #define XFS_RANDOM_SWAPEXT_FINISH_ONE 1
> +#define XFS_RANDOM_BULKSTAT_REDUCE_MAX_IEXTENTS 1
>
> #endif /* __XFS_ERRORTAG_H_ */
> diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
> index e25b440cbfd3..e2a9446fb025 100644
> --- a/fs/xfs/xfs_error.c
> +++ b/fs/xfs/xfs_error.c
> @@ -58,6 +58,7 @@ static unsigned int xfs_errortag_random_default[] = {
> XFS_RANDOM_BMAP_ALLOC_MINLEN_EXTENT,
> XFS_RANDOM_AG_RESV_FAIL,
> XFS_RANDOM_SWAPEXT_FINISH_ONE,
> + XFS_RANDOM_BULKSTAT_REDUCE_MAX_IEXTENTS,
> };
>
> struct xfs_errortag_attr {
> @@ -172,6 +173,7 @@ 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(ag_resv_fail, XFS_ERRTAG_AG_RESV_FAIL);
> XFS_ERRORTAG_ATTR_RW(swapext_finish_one, XFS_RANDOM_SWAPEXT_FINISH_ONE);
> +XFS_ERRORTAG_ATTR_RW(bulkstat_reduce_max_iextents, XFS_ERRTAG_BULKSTAT_REDUCE_MAX_IEXTENTS);
>
> static struct attribute *xfs_errortag_attrs[] = {
> XFS_ERRORTAG_ATTR_LIST(noerror),
> @@ -214,6 +216,7 @@ static struct attribute *xfs_errortag_attrs[] = {
> XFS_ERRORTAG_ATTR_LIST(bmap_alloc_minlen_extent),
> XFS_ERRORTAG_ATTR_LIST(ag_resv_fail),
> XFS_ERRORTAG_ATTR_LIST(swapext_finish_one),
> + XFS_ERRORTAG_ATTR_LIST(bulkstat_reduce_max_iextents),
> NULL,
> };
>
> diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
> index 8493870a0a87..1b252d1cda9d 100644
> --- a/fs/xfs/xfs_itable.c
> +++ b/fs/xfs/xfs_itable.c
> @@ -20,6 +20,7 @@
> #include "xfs_icache.h"
> #include "xfs_health.h"
> #include "xfs_trans.h"
> +#include "xfs_errortag.h"
>
> /*
> * Bulk Stat
> @@ -143,7 +144,13 @@ xfs_bulkstat_one_int(
>
> nextents = xfs_ifork_nextents(&ip->i_df);
> if (bc->breq->version != XFS_BULKSTAT_VERSION_V6) {
> - if (nextents > XFS_IFORK_EXTCNT_MAXS32) {
> + xfs_extnum_t max_nextents = XFS_IFORK_EXTCNT_MAXS32;
> +
> + if (unlikely(XFS_TEST_ERROR(false, mp,
> + XFS_ERRTAG_BULKSTAT_REDUCE_MAX_IEXTENTS)))
> + max_nextents = 10;
> +
> + if (nextents > max_nextents) {
> xfs_iunlock(ip, XFS_ILOCK_SHARED);
> xfs_irele(ip);
> error = -EINVAL;
> --
> 2.30.2
>
