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>

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index dce971d..5b23f2d 100644 (file)
--- 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,