diff --git a/drivers/md/md.c b/drivers/md/md.c
index 288d26013de2..f16f190546ef 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5759,10 +5759,6 @@ static int md_alloc(dev_t dev, char *name)
 	disk->flags |= GENHD_FL_EXT_DEVT;
 	disk->events |= DISK_EVENT_MEDIA_CHANGE;
 	mddev->gendisk = disk;
-	/* As soon as we call add_disk(), another thread could get
-	 * through to md_open, so make sure it doesn't get too far
-	 */
-	mutex_lock(&mddev->open_mutex);
 	add_disk(disk);
 
 	error = kobject_add(&mddev->kobj, &disk_to_dev(disk)->kobj, "%s", "md");
@@ -5777,7 +5773,6 @@ static int md_alloc(dev_t dev, char *name)
 	if (mddev->kobj.sd &&
 	    sysfs_create_group(&mddev->kobj, &md_bitmap_group))
 		pr_debug("pointless warning\n");
-	mutex_unlock(&mddev->open_mutex);
  abort:
 	mutex_unlock(&disks_mutex);
 	if (!error && mddev->kobj.sd) {