From af347335939531eeb5701f52549cc4d366eb60d5 Mon Sep 17 00:00:00 2001
From: Rodrigo Balerdi <lanchon@gmail.com>
Date: Tue, 3 May 2022 03:47:43 -0300
Subject: [PATCH] base-files: fix ubinized nand sysupgrade

It has been reported that ubinized nand sysupgrade fails under certain
circumstances, being unable to detach the existing ubi partition due to
volumes within the partition being mounted.

This is an attempt to solve such issues by unmounting and removing
ubiblock devices and unmounting ubi volumes within the target partition
prior to detaching and formatting it.

Signed-off-by: Rodrigo Balerdi <lanchon@gmail.com>
---
 package/base-files/files/lib/upgrade/nand.sh | 45 ++++++++++++++------
 package/base-files/files/lib/upgrade/stage2  |  2 +-
 2 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/package/base-files/files/lib/upgrade/nand.sh b/package/base-files/files/lib/upgrade/nand.sh
index 76a984483e0..19e51c55c0d 100644
--- a/package/base-files/files/lib/upgrade/nand.sh
+++ b/package/base-files/files/lib/upgrade/nand.sh
@@ -127,17 +127,41 @@ nand_restore_config() {
 }
 
 nand_remove_ubiblock() {
-	local ubivol=$1
-	local ubiblk=ubiblock${ubivol:3}
-	if [ -e /dev/$ubiblk ]; then
-		echo "removing $ubiblk"
-		if ! ubiblock -r /dev/$ubivol; then
+	local ubivol="$1"
+
+	local ubiblk="ubiblock${ubivol:3}"
+	if [ -e "/dev/$ubiblk" ]; then
+		umount "/dev/$ubiblk" && echo "unmounted /dev/$ubiblk" || :
+		if ! ubiblock -r "/dev/$ubivol"; then
 			echo "cannot remove $ubiblk"
 			return 1
 		fi
 	fi
 }
 
+nand_detach_ubi() {
+	local ubipart="$1"
+
+	local mtdnum="$( find_mtd_index "$ubipart" )"
+	if [ ! "$mtdnum" ]; then
+		echo "cannot find ubi mtd partition $ubipart"
+		return 1
+	fi
+
+	local ubidev="$( nand_find_ubi "$ubipart" )"
+	if [ "$ubidev" ]; then
+		for ubivol in $(find /dev -name "${ubidev}_*" -maxdepth 1 | sort); do
+			ubivol="${ubivol:5}"
+			nand_remove_ubiblock "$ubivol" || :
+			umount "/dev/$ubivol" && echo "unmounted /dev/$ubivol" || :
+		done
+		if ! ubidetach -m "$mtdnum"; then
+			echo "cannot detach ubi mtd partition $ubipart"
+			return 1
+		fi
+	fi
+}
+
 nand_upgrade_prepare_ubi() {
 	local rootfs_length="$1"
 	local rootfs_type="$2"
@@ -235,15 +259,10 @@ nand_upgrade_prepare_ubi() {
 nand_upgrade_ubinized() {
 	local ubi_file="$1"
 
-	local mtdnum="$( find_mtd_index "$CI_UBIPART" )"
-	if [ ! "$mtdnum" ]; then
-		echo "cannot find ubi mtd partition $CI_UBIPART"
-		return 1
-	fi
+	nand_detach_ubi "$CI_UBIPART" || return 1
 
-	local mtddev="/dev/mtd${mtdnum}"
-	ubidetach -p "${mtddev}" || :
-	ubiformat "${mtddev}" -y -f "${ubi_file}" && ubiattach -p "${mtddev}"
+	local mtdnum="$( find_mtd_index "$CI_UBIPART" )"
+	ubiformat "/dev/mtd$mtdnum" -y -f "$ubi_file" && ubiattach -m "$mtdnum"
 }
 
 # Write the UBIFS image to UBI rootfs volume
diff --git a/package/base-files/files/lib/upgrade/stage2 b/package/base-files/files/lib/upgrade/stage2
index 5e0d73631b0..97e0b881e9a 100755
--- a/package/base-files/files/lib/upgrade/stage2
+++ b/package/base-files/files/lib/upgrade/stage2
@@ -41,7 +41,7 @@ switch_to_ramfs() {
 		pivot_root mount_root reboot sync kill sleep		\
 		md5sum hexdump cat zcat dd tar				\
 		ls basename find cp mv rm mkdir rmdir mknod touch chmod \
-		'[' printf wc grep awk sed cut				\
+		'[' printf wc grep awk sed cut sort			\
 		mtd partx losetup mkfs.ext4 nandwrite flash_erase	\
 		ubiupdatevol ubiattach ubiblock ubiformat		\
 		ubidetach ubirsvol ubirmvol ubimkvol			\