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authorDarrick J. Wong <djwong@kernel.org>2022-11-08 16:37:17 -0800
committerDarrick J. Wong <djwong@kernel.org>2022-11-09 10:11:18 -0800
commitae19972d368b6a3d9ea239c6c77411ce0ecfcc00 (patch)
tree36d8ebc9a6cbfc5b0d21093bb50e901527c151af
parent2ede1a74dfbfcea89b3bacb5bc2f130b68d85882 (diff)
xfs: add debug knob to slow down write for funiomap-write-races-6.2_2022-11-09
Add a new error injection knob so that we can arbitrarily slow down pagecahe writes 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 XXXXXXXXXXXX that fixes write racing with reclaim writeback. Signed-off-by: Darrick J. Wong <djwong@kernel.org>
-rw-r--r--fs/xfs/libxfs/xfs_errortag.h4
-rw-r--r--fs/xfs/xfs_error.c3
-rw-r--r--fs/xfs/xfs_iomap.c12
3 files changed, 16 insertions, 3 deletions
diff --git a/fs/xfs/libxfs/xfs_errortag.h b/fs/xfs/libxfs/xfs_errortag.h
index 7c723a36df02..7e04523f44f2 100644
--- a/fs/xfs/libxfs/xfs_errortag.h
+++ b/fs/xfs/libxfs/xfs_errortag.h
@@ -62,7 +62,8 @@
#define XFS_ERRTAG_DA_LEAF_SPLIT 40
#define XFS_ERRTAG_ATTR_LEAF_TO_NODE 41
#define XFS_ERRTAG_WB_DELAY_MS 44
-#define XFS_ERRTAG_MAX 45
+#define XFS_ERRTAG_WRITE_DELAY_MS 45
+#define XFS_ERRTAG_MAX 46
/*
* Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
@@ -109,5 +110,6 @@
#define XFS_RANDOM_DA_LEAF_SPLIT 1
#define XFS_RANDOM_ATTR_LEAF_TO_NODE 1
#define XFS_RANDOM_WB_DELAY_MS 3000
+#define XFS_RANDOM_WRITE_DELAY_MS 3000
#endif /* __XFS_ERRORTAG_H_ */
diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
index b949cfe7dd18..ee00f5ab11a7 100644
--- a/fs/xfs/xfs_error.c
+++ b/fs/xfs/xfs_error.c
@@ -63,6 +63,7 @@ static unsigned int xfs_errortag_random_default[] = {
0, /* 42 */
0, /* 43 */
XFS_RANDOM_WB_DELAY_MS,
+ XFS_RANDOM_WRITE_DELAY_MS,
};
struct xfs_errortag_attr {
@@ -179,6 +180,7 @@ XFS_ERRORTAG_ATTR_RW(larp, XFS_ERRTAG_LARP);
XFS_ERRORTAG_ATTR_RW(da_leaf_split, XFS_ERRTAG_DA_LEAF_SPLIT);
XFS_ERRORTAG_ATTR_RW(attr_leaf_to_node, XFS_ERRTAG_ATTR_LEAF_TO_NODE);
XFS_ERRORTAG_ATTR_RW(wb_delay_ms, XFS_ERRTAG_WB_DELAY_MS);
+XFS_ERRORTAG_ATTR_RW(write_delay_ms, XFS_ERRTAG_WRITE_DELAY_MS);
static struct attribute *xfs_errortag_attrs[] = {
XFS_ERRORTAG_ATTR_LIST(noerror),
@@ -223,6 +225,7 @@ static struct attribute *xfs_errortag_attrs[] = {
XFS_ERRORTAG_ATTR_LIST(da_leaf_split),
XFS_ERRORTAG_ATTR_LIST(attr_leaf_to_node),
XFS_ERRORTAG_ATTR_LIST(wb_delay_ms),
+ XFS_ERRORTAG_ATTR_LIST(write_delay_ms),
NULL,
};
ATTRIBUTE_GROUPS(xfs_errortag);
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 5e746df2c63f..048e7d9a739b 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -27,6 +27,8 @@
#include "xfs_dquot_item.h"
#include "xfs_dquot.h"
#include "xfs_reflink.h"
+#include "xfs_error.h"
+#include "xfs_errortag.h"
#define XFS_ALLOC_ALIGN(mp, off) \
(((off) >> mp->m_allocsize_log) << mp->m_allocsize_log)
@@ -1368,11 +1370,17 @@ xfs_buffered_write_iomap_valid(
struct xfs_iomap_buffered_ctx *ibc = iter->private;
struct xfs_inode *ip = XFS_I(iter->inode);
- if (ibc->data_seq != READ_ONCE(ip->i_df.if_seq))
+ if (ibc->data_seq != READ_ONCE(ip->i_df.if_seq)) {
+ XFS_ERRORTAG_REPORT(ip->i_mount, XFS_ERRTAG_WRITE_DELAY_MS);
return false;
+ }
if (ibc->has_cow_seq &&
- ibc->cow_seq != READ_ONCE(ip->i_cowfp->if_seq))
+ ibc->cow_seq != READ_ONCE(ip->i_cowfp->if_seq)) {
+ XFS_ERRORTAG_REPORT(ip->i_mount, XFS_ERRTAG_WRITE_DELAY_MS);
return false;
+ }
+
+ XFS_ERRORTAG_DELAY(ip->i_mount, XFS_ERRTAG_WRITE_DELAY_MS);
return true;
}