diff --git a/drivers/md/md.c b/drivers/md/md.c
index 4f5ecbe94ccb..b8247bc32cf6 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5409,9 +5409,13 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
 		 * which will now never happen */
 		wake_up_process(mddev->sync_thread->tsk);
 
+	if (mddev->external && test_bit(MD_CHANGE_PENDING, &mddev->flags))
+		return -EBUSY;
 	mddev_unlock(mddev);
 	wait_event(resync_wait, !test_bit(MD_RECOVERY_RUNNING,
 					  &mddev->recovery));
+	wait_event(mddev->sb_wait,
+		   !test_bit(MD_CHANGE_PENDING, &mddev->flags));
 	mddev_lock_nointr(mddev);
 
 	mutex_lock(&mddev->open_mutex);