diff --git a/drivers/md/md.c b/drivers/md/md.c
index e10d91122483..3ce5f4e0f431 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -746,6 +746,22 @@ static struct mddev *mddev_find_locked(dev_t unit)
 }
 
 static struct mddev *mddev_find(dev_t unit)
+{
+	struct mddev *mddev;
+
+	if (MAJOR(unit) != MD_MAJOR)
+		unit &= ~((1 << MdpMinorShift) - 1);
+
+	spin_lock(&all_mddevs_lock);
+	mddev = mddev_find_locked(unit);
+	if (mddev)
+		mddev_get(mddev);
+	spin_unlock(&all_mddevs_lock);
+
+	return mddev;
+}
+
+static struct mddev *mddev_find_or_alloc(dev_t unit)
 {
 	struct mddev *mddev, *new = NULL;
 
@@ -5650,7 +5666,7 @@ static int md_alloc(dev_t dev, char *name)
 	 * writing to /sys/module/md_mod/parameters/new_array.
 	 */
 	static DEFINE_MUTEX(disks_mutex);
-	struct mddev *mddev = mddev_find(dev);
+	struct mddev *mddev = mddev_find_or_alloc(dev);
 	struct gendisk *disk;
 	int partitioned;
 	int shift;
@@ -6530,11 +6546,9 @@ static void autorun_devices(int part)
 
 		md_probe(dev);
 		mddev = mddev_find(dev);
-		if (!mddev || !mddev->gendisk) {
-			if (mddev)
-				mddev_put(mddev);
+		if (!mddev)
 			break;
-		}
+
 		if (mddev_lock(mddev))
 			pr_warn("md: %s locked, cannot run\n", mdname(mddev));
 		else if (mddev->raid_disks || mddev->major_version