dm mpath: make it easier to detect unintended I/O request flushes
I/O errors triggered by multipathd incorrectly not enabling the no-flush
flag for DM_DEVICE_SUSPEND or DM_DEVICE_RESUME are hard to debug. Add
more logging to make it easier to debug this.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index cc52953..fd7cdc4 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -442,6 +442,23 @@
}
/*
+ * dm_report_EIO() is a macro instead of a function to make pr_debug()
+ * report the function name and line number of the function from which
+ * it has been invoked.
+ */
+#define dm_report_EIO(m) \
+({ \
+ struct mapped_device *md = dm_table_get_md((m)->ti->table); \
+ \
+ pr_debug("%s: returning EIO; QIFNP = %d; SQIFNP = %d; DNFS = %d\n", \
+ dm_device_name(md), \
+ test_bit(MPATHF_QUEUE_IF_NO_PATH, &(m)->flags), \
+ test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &(m)->flags), \
+ dm_noflush_suspending((m)->ti)); \
+ -EIO; \
+})
+
+/*
* Map cloned requests (request-based multipath)
*/
static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
@@ -464,7 +481,7 @@
if (!pgpath) {
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
return DM_MAPIO_DELAY_REQUEUE;
- return -EIO; /* Failed */
+ return dm_report_EIO(m); /* Failed */
} else if (test_bit(MPATHF_QUEUE_IO, &m->flags) ||
test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
if (pg_init_all_paths(m))
@@ -541,7 +558,7 @@
if (!pgpath) {
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
return DM_MAPIO_REQUEUE;
- return -EIO;
+ return dm_report_EIO(m);
}
mpio->pgpath = pgpath;
@@ -1476,7 +1493,7 @@
if (atomic_read(&m->nr_valid_paths) == 0 &&
!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
- r = -EIO;
+ r = dm_report_EIO(m);
return r;
}
@@ -1519,7 +1536,7 @@
if (atomic_read(&m->nr_valid_paths) == 0 &&
!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
- return -EIO;
+ return dm_report_EIO(m);
/* Queue for the daemon to resubmit */
dm_bio_restore(get_bio_details_from_bio(clone), clone);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 4566024..dbfaf6d 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2169,6 +2169,8 @@
*/
if (noflush)
set_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
+ else
+ pr_debug("%s: suspending with flush\n", dm_device_name(md));
/*
* This gets reverted if there's an error later and the targets