[PATCH 12/18] xfs: add error injection to test swapext recovery

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

Add an errortag so that we can test recovery of swapext log items.

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_errortag.h |    4 +++-
 fs/xfs/libxfs/xfs_swapext.c  |    5 +++++
 fs/xfs/xfs_error.c           |    3 +++
 3 files changed, 11 insertions(+), 1 deletion(-)


diff --git a/fs/xfs/libxfs/xfs_errortag.h b/fs/xfs/libxfs/xfs_errortag.h
index 79e6c4fb1d8a..e99683558ccc 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_SWAPEXT_FINISH_ONE			35
+#define XFS_ERRTAG_MAX					36
 
 /*
  * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
@@ -94,6 +95,7 @@
 #define XFS_RANDOM_BUF_LRU_REF				2
 #define XFS_RANDOM_FORCE_SCRUB_REPAIR			1
 #define XFS_RANDOM_FORCE_SUMMARY_RECALC			1
+#define XFS_RANDOM_SWAPEXT_FINISH_ONE			1
 #define XFS_RANDOM_IUNLINK_FALLBACK			(XFS_RANDOM_DEFAULT/10)
 
 #endif /* __XFS_ERRORTAG_H_ */
diff --git a/fs/xfs/libxfs/xfs_swapext.c b/fs/xfs/libxfs/xfs_swapext.c
index 2eff48453070..6597c613fa3e 100644
--- a/fs/xfs/libxfs/xfs_swapext.c
+++ b/fs/xfs/libxfs/xfs_swapext.c
@@ -18,6 +18,8 @@
 #include "xfs_quota.h"
 #include "xfs_swapext.h"
 #include "xfs_trace.h"
+#include "xfs_errortag.h"
+#include "xfs_error.h"
 
 /* Information to help us reset reflink flag / CoW fork state after a swap. */
 
@@ -354,6 +356,9 @@ xfs_swapext_finish_one(
 		xfs_trans_log_inode(tp, sxi->si_ip2, XFS_ILOG_CORE);
 	}
 
+	if (XFS_TEST_ERROR(false, tp->t_mountp, XFS_ERRTAG_SWAPEXT_FINISH_ONE))
+		return -EIO;
+
 	if (xfs_swapext_has_more_work(sxi))
 		trace_xfs_swapext_defer(tp->t_mountp, sxi);
 	return 0;
diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
index a21e9cc6516a..d818497afa2c 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_SWAPEXT_FINISH_ONE,
 };
 
 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(swapext_finish_one, XFS_RANDOM_SWAPEXT_FINISH_ONE);
 
 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(swapext_finish_one),
 	NULL,
 };