diff --git a/drivers/md/md.c b/drivers/md/md.c
index a04485cdae296dfebdf06154ef4da1e347247374..abf58ef633a39a87d40a77aebd7ecc510d2ddde5 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -697,6 +697,7 @@ void mddev_init(struct mddev *mddev)
 	atomic_set(&mddev->active, 1);
 	atomic_set(&mddev->openers, 0);
 	atomic_set(&mddev->active_io, 0);
+	atomic_set(&mddev->sync_seq, 0);
 	spin_lock_init(&mddev->lock);
 	atomic_set(&mddev->flush_pending, 0);
 	init_waitqueue_head(&mddev->sb_wait);
@@ -4876,19 +4877,28 @@ static void stop_sync_thread(struct mddev *mddev)
 	if (work_pending(&mddev->del_work))
 		flush_workqueue(md_misc_wq);
 
-	if (mddev->sync_thread) {
-		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
-		md_reap_sync_thread(mddev);
-	}
+	set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+	/*
+	 * Thread might be blocked waiting for metadata update which will now
+	 * never happen.
+	 */
+	if (mddev->sync_thread)
+		wake_up_process(mddev->sync_thread->tsk);
 
 	mddev_unlock(mddev);
 }
 
 static void idle_sync_thread(struct mddev *mddev)
 {
+	int sync_seq = atomic_read(&mddev->sync_seq);
+
 	mutex_lock(&mddev->sync_mutex);
 	clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 	stop_sync_thread(mddev);
+
+	wait_event(resync_wait, sync_seq != atomic_read(&mddev->sync_seq) ||
+			!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery));
+
 	mutex_unlock(&mddev->sync_mutex);
 }
 
@@ -4897,6 +4907,10 @@ static void frozen_sync_thread(struct mddev *mddev)
 	mutex_lock(&mddev->sync_mutex);
 	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 	stop_sync_thread(mddev);
+
+	wait_event(resync_wait, mddev->sync_thread == NULL &&
+			!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery));
+
 	mutex_unlock(&mddev->sync_mutex);
 }
 
@@ -9471,6 +9485,8 @@ void md_reap_sync_thread(struct mddev *mddev)
 
 	/* resync has finished, collect result */
 	md_unregister_thread(&mddev->sync_thread);
+	atomic_inc(&mddev->sync_seq);
+
 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
 	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
 	    mddev->degraded != mddev->raid_disks) {
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 50c7d3e4f2d7edbf7226aecc02da47b55d0137b8..4565f17fc0489889c215c0c3305883dc5b8fd6d1 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -531,6 +531,8 @@ struct mddev {
 
 	/* Used to synchronize idle and frozen for action_store() */
 	struct mutex sync_mutex;
+	/* The sequence number for sync thread */
+	atomic_t sync_seq;
 };
 
 enum recovery_flags {