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Code Issues Releases Wiki Activity

dm mpath: enhance queue_if_no_path debugging 

Add more DMDEBUG that shows arguments passed and caller, and another
that shows state of related flags at end of queue_if_no_path().

Also add queue_if_no_path DMDEBUG to multipath_resume().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mike Snitzer 2020-05-29 15:59:13 -04:00
parent 553ec94cb4
commit 4c3f48380f
1 changed files with 23 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
drivers/md/dm-mpath.c
View File

@ -692,10 +692,14 @@ static void process_queued_bios(struct work_struct *work)
* If we run out of usable paths, should we queue I/O or error it?
*/
static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,
bool save_old_value)
bool save_old_value, const char *caller)
{
unsigned long flags;
bool queue_if_no_path_bit, saved_queue_if_no_path_bit;
const char *dm_dev_name = dm_device_name(dm_table_get_md(m->ti->table));
DMDEBUG("%s: %s caller=%s queue_if_no_path=%d save_old_value=%d",
dm_dev_name, __func__, caller, queue_if_no_path, save_old_value);
spin_lock_irqsave(&m->lock, flags);
@ -705,7 +709,7 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,
if (save_old_value) {
if (unlikely(!queue_if_no_path_bit && saved_queue_if_no_path_bit)) {
DMERR("%s: QIFNP disabled but saved as enabled, saving again loses state, not saving!",
dm_device_name(dm_table_get_md(m->ti->table)));
dm_dev_name);
} else
assign_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags, queue_if_no_path_bit);
} else if (!queue_if_no_path && saved_queue_if_no_path_bit) {
@ -714,6 +718,12 @@ static int queue_if_no_path(struct multipath *m, bool queue_if_no_path,
}
assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags, queue_if_no_path);
DMDEBUG("%s: after %s changes; QIFNP = %d; SQIFNP = %d; DNFS = %d",
dm_dev_name, __func__,
test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags),
test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags),
dm_noflush_suspending(m->ti));
spin_unlock_irqrestore(&m->lock, flags);
if (!queue_if_no_path) {
@ -734,7 +744,7 @@ static void queue_if_no_path_timeout_work(struct timer_list *t)
struct mapped_device *md = dm_table_get_md(m->ti->table);
DMWARN("queue_if_no_path timeout on %s, failing queued IO", dm_device_name(md));
queue_if_no_path(m, false, false);
queue_if_no_path(m, false, false, __func__);
}
/*
@ -1074,7 +1084,7 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m)
argc--;
if (!strcasecmp(arg_name, "queue_if_no_path")) {
r = queue_if_no_path(m, true, false);
r = queue_if_no_path(m, true, false, __func__);
continue;
}
@ -1678,7 +1688,7 @@ static void multipath_presuspend(struct dm_target *ti)
/* FIXME: bio-based shouldn't need to always disable queue_if_no_path */
if (m->queue_mode == DM_TYPE_BIO_BASED || !dm_noflush_suspending(m->ti))
queue_if_no_path(m, false, true);
queue_if_no_path(m, false, true, __func__);
}
static void multipath_postsuspend(struct dm_target *ti)
@ -1703,6 +1713,12 @@ static void multipath_resume(struct dm_target *ti)
set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
}
DMDEBUG("%s: %s finished; QIFNP = %d; SQIFNP = %d",
dm_device_name(dm_table_get_md(m->ti->table)), __func__,
test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags),
test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags));
spin_unlock_irqrestore(&m->lock, flags);
}
@ -1862,13 +1878,13 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv,
if (argc == 1) {
if (!strcasecmp(argv[0], "queue_if_no_path")) {
r = queue_if_no_path(m, true, false);
r = queue_if_no_path(m, true, false, __func__);
spin_lock_irqsave(&m->lock, flags);
enable_nopath_timeout(m);
spin_unlock_irqrestore(&m->lock, flags);
goto out;
} else if (!strcasecmp(argv[0], "fail_if_no_path")) {
r = queue_if_no_path(m, false, false);
r = queue_if_no_path(m, false, false, __func__);
disable_nopath_timeout(m);
goto out;
}