[PATCH v5 11/14] dm-raid: add a new helper prepare_suspend() in md_personality

[Yu Kuai]

From: Yu Kuai <yuku...@huawei.com>

There are no functional changes for now, prepare to fix a deadlock for
dm-raid456.

Signed-off-by: Yu Kuai <yuku...@huawei.com>
---
 drivers/md/dm-raid.c | 10 +++++++---
 drivers/md/md.h      |  1 +
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 6b6c011d9f69..16d3348abfed 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -3806,10 +3806,14 @@ static void raid_io_hints(struct dm_target *ti, struct 
queue_limits *limits)
 static void raid_presuspend(struct dm_target *ti)
 {
        struct raid_set *rs = ti->private;
+       struct mddev *mddev = &rs->md;
 
-       mddev_lock_nointr(&rs->md);
-       md_frozen_sync_thread(&rs->md);
-       mddev_unlock(&rs->md);
+       mddev_lock_nointr(mddev);
+       md_frozen_sync_thread(mddev);
+       mddev_unlock(mddev);
+
+       if (mddev->pers && mddev->pers->prepare_suspend)
+               mddev->pers->prepare_suspend(mddev);
 }
 
 static void raid_presuspend_undo(struct dm_target *ti)
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 684cc866402a..8e81f9e2fb20 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -629,6 +629,7 @@ struct md_personality
        int (*start_reshape) (struct mddev *mddev);
        void (*finish_reshape) (struct mddev *mddev);
        void (*update_reshape_pos) (struct mddev *mddev);
+       void (*prepare_suspend) (struct mddev *mddev);
        /* quiesce suspends or resumes internal processing.
         * 1 - stop new actions and wait for action io to complete
         * 0 - return to normal behaviour
-- 
2.39.2