[RFC v5 PATCH 8/9] xfs: create an error tag for random relog reservation

[Brian Foster <bfoster@xxxxxxxxxx>]

Create an errortag to randomly enable relogging on permanent
transactions. This only stresses relog reservation management and
does not enable relogging of any particular items. The tag will be
reused in a subsequent patch to enable random item relogging.

Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_errortag.h | 4 +++-
 fs/xfs/xfs_error.c           | 3 +++
 fs/xfs/xfs_trans.c           | 6 ++++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/libxfs/xfs_errortag.h b/fs/xfs/libxfs/xfs_errortag.h
index 79e6c4fb1d8a..ca7bcadb9455 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_RELOG				35
+#define XFS_ERRTAG_MAX					36
 
 /*
  * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
@@ -95,5 +96,6 @@
 #define XFS_RANDOM_FORCE_SCRUB_REPAIR			1
 #define XFS_RANDOM_FORCE_SUMMARY_RECALC			1
 #define XFS_RANDOM_IUNLINK_FALLBACK			(XFS_RANDOM_DEFAULT/10)
+#define XFS_RANDOM_RELOG				XFS_RANDOM_DEFAULT
 
 #endif /* __XFS_ERRORTAG_H_ */
diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
index 331765afc53e..2838b909287e 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_RELOG,
 };
 
 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(relog,		XFS_ERRTAG_RELOG);
 
 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(relog),
 	NULL,
 };
 
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index f7f2411ead4e..24e0208b74b8 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -19,6 +19,7 @@
 #include "xfs_trace.h"
 #include "xfs_error.h"
 #include "xfs_defer.h"
+#include "xfs_errortag.h"
 
 kmem_zone_t	*xfs_trans_zone;
 
@@ -263,6 +264,11 @@ xfs_trans_alloc(
 	struct xfs_trans	*tp;
 	int			error;
 
+	/* relogging requires permanent transactions */
+	if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_RELOG) &&
+	    resp->tr_logflags & XFS_TRANS_PERM_LOG_RES)
+		flags |= XFS_TRANS_RELOG;
+
 	/*
 	 * Allocate the handle before we do our freeze accounting and setting up
 	 * GFP_NOFS allocation context so that we avoid lockdep false positives
-- 
2.21.1