[PATCH -next 4/5] md: add a new api prepare_suspend() in md_personality

[Yu Kuai]

From: Yu Kuai <yukuai3@xxxxxxxxxx>

There are no functional changes, the new api will be used later to do
special handling for raid456 in md_suspend().

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
 drivers/md/md.c | 4 ++++
 drivers/md/md.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5db26b7e7314..1ef81421e131 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -467,6 +467,10 @@ void mddev_suspend(struct mddev *mddev)
 	wake_up(&mddev->sb_wait);
 	set_bit(MD_ALLOW_SB_UPDATE, &mddev->flags);
 	percpu_ref_kill(&mddev->active_io);
+
+	if (mddev->pers->prepare_suspend)
+		mddev->pers->prepare_suspend(mddev);
+
 	wait_event(mddev->sb_wait, percpu_ref_is_zero(&mddev->active_io));
 	mddev->pers->quiesce(mddev, 1);
 	clear_bit_unlock(MD_ALLOW_SB_UPDATE, &mddev->flags);
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 7827f27c1406..15d82517572e 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -639,6 +639,7 @@ 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