dm mpath: flush workqueues before suspend completes

This patch stops the remaining dm-mpath activity during the suspend
sequence by flushing workqueues in postsuspend function.

The current dm-mpath target may not be quiet even after suspend completes
because some workqueues (e.g. device_handler's work, event handling)
are not flushed during the suspend sequence, even though suspended
devices/targets are supposed to be quiet in this state.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index dce971dbdfa3..5b23f2df9bde 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -885,13 +885,18 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
         return r;
 }
 
-static void multipath_dtr(struct dm_target *ti)
+static void flush_multipath_work(void)
 {
-        struct multipath *m = (struct multipath *) ti->private;
-
         flush_workqueue(kmpath_handlerd);
         flush_workqueue(kmultipathd);
         flush_scheduled_work();
+}
+
+static void multipath_dtr(struct dm_target *ti)
+{
+        struct multipath *m = ti->private;
+
+        flush_multipath_work();
         free_multipath(m);
 }
 
@@ -1261,6 +1266,11 @@ static void multipath_presuspend(struct dm_target *ti)
         queue_if_no_path(m, 0, 1);
 }
 
+static void multipath_postsuspend(struct dm_target *ti)
+{
+        flush_multipath_work();
+}
+
 /*
  * Restore the queue_if_no_path setting.
  */
@@ -1567,13 +1577,14 @@ out:
  *---------------------------------------------------------------*/
 static struct target_type multipath_target = {
         .name = "multipath",
-        .version = {1, 1, 0},
+        .version = {1, 1, 1},
         .module = THIS_MODULE,
         .ctr = multipath_ctr,
         .dtr = multipath_dtr,
         .map_rq = multipath_map,
         .rq_end_io = multipath_end_io,
         .presuspend = multipath_presuspend,
+        .postsuspend = multipath_postsuspend,
         .resume = multipath_resume,
         .status = multipath_status,
         .message = multipath_message,