openwrt/target/linux/generic/pending-5.4/493-ubi-set-ROOT_DEV-to-ubiblock-rootfs-if-unset.patch

From: Daniel Golle <daniel@makrotopia.org>
Subject: ubi: set ROOT_DEV to ubiblock "rootfs" if unset

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 drivers/mtd/ubi/block.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -42,6 +42,7 @@
 #include <linux/scatterlist.h>
 #include <linux/idr.h>
 #include <asm/div64.h>
+#include <linux/root_dev.h>
 
 #include "ubi-media.h"
 #include "ubi.h"
@@ -458,6 +459,15 @@ int ubiblock_create(struct ubi_volume_in
 	dev_info(disk_to_dev(dev->gd), "created from ubi%d:%d(%s)",
 		 dev->ubi_num, dev->vol_id, vi->name);
 	mutex_unlock(&devices_mutex);
+
+	if (!strcmp(vi->name, "rootfs") &&
+	    IS_ENABLED(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
+	    ROOT_DEV == 0) {
+		pr_notice("ubiblock: device ubiblock%d_%d (%s) set to be root filesystem\n",
+			  dev->ubi_num, dev->vol_id, vi->name);
+		ROOT_DEV = MKDEV(gd->major, gd->first_minor);
+	}
+
 	return 0;
 
 out_free_queue: