On Mon, Nov 28, 2022 at 05:21:18PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> Add a new error injection knob so that we can arbitrarily slow down
> writeback to test for race conditions and aberrant reclaim behavior if
> the writeback mechanisms are slow to issue writeback. This will enable
> functional testing for the ifork sequence counters introduced in commit
> 745b3f76d1c8 ("xfs: maintain a sequence count for inode fork
> manipulations").
>
> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> ---
> v2: this time with tracepoints
> ---
.....
> @@ -267,6 +270,14 @@ xfs_errortag_valid(
> return true;
> }
>
> +bool
> +xfs_errortag_enabled(
> + struct xfs_mount *mp,
> + unsigned int tag)
> +{
> + return mp->m_errortag && mp->m_errortag[tag] != 0;
> +}
Perhaps consider using the new xfs_errortag_valid() helper? i.e.
{
if (!mp->errortag)
return false;
if (!xfs_errortag_valid(tag))
return false;
return mp->m_errortag[tag] != 0;
}
> +
> bool
> xfs_errortag_test(
> struct xfs_mount *mp,
> diff --git a/fs/xfs/xfs_error.h b/fs/xfs/xfs_error.h
> index 5191e9145e55..936d0c52d6af 100644
> --- a/fs/xfs/xfs_error.h
> +++ b/fs/xfs/xfs_error.h
> @@ -45,6 +45,17 @@ extern bool xfs_errortag_test(struct xfs_mount *mp, const char *expression,
> const char *file, int line, unsigned int error_tag);
> #define XFS_TEST_ERROR(expr, mp, tag) \
> ((expr) || xfs_errortag_test((mp), #expr, __FILE__, __LINE__, (tag)))
> +bool xfs_errortag_enabled(struct xfs_mount *mp, unsigned int tag);
> +#define XFS_ERRORTAG_DELAY(mp, tag) \
> + do { \
> + if (!xfs_errortag_enabled((mp), (tag))) \
> + break; \
> + xfs_warn_ratelimited((mp), \
> +"Injecting %ums delay at file %s, line %d, on filesystem \"%s\"", \
> + (mp)->m_errortag[(tag)], __FILE__, __LINE__, \
> + (mp)->m_super->s_id); \
> + mdelay((mp)->m_errortag[(tag)]); \
> + } while (0)
Putting a might_sleep() in this macro might be a good idea - that
will catch delays being added inside spin lock contexts...
Other than that, it looks fine.
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
--
Dave Chinner
david@xxxxxxxxxxxxx
