armbian-next: refactor losetup -d ... into free_loop_device_insistent() which retries 10 times

lib/functions/image/loop.sh

@@ -51,18 +51,8 @@ function check_loop_device_internal() {
 	return 0
 }
 
-#
-# Copyright (c) 2013-2021 Igor Pecovnik, igor.pecovnik@gma**.com
-#
-# This file is licensed under the terms of the GNU General Public
-# License version 2. This program is licensed "as is" without any
-# warranty of any kind, whether express or implied.
-#
-# This file is a part of the Armbian build script
-# https://github.com/armbian/build/
-
-# write_uboot <loopdev>
-#
+# write_uboot_to_loop_image <loopdev>
+# @TODO: isnt this supposed to be u-boot related? why in loop.sh?
 write_uboot_to_loop_image() {
 
 	local loop=$1 revision
@@ -102,3 +92,14 @@ write_uboot_to_loop_image() {
 
 	return 0
 }
+
+# This exists to prevent silly failures; sometimes the user is inspecting the directory outside of build, etc.
+function free_loop_device_insistent() {
+	display_alert "Freeing loop device" "${1}"
+	do_with_retries 10 free_loop_device_retried "${1}"
+}
+
+function free_loop_device_retried() {
+	display_alert "Freeing loop device (try ${RETRY_RUNS})" "${1}"
+	losetup -d "${1}"
+}

lib/functions/image/rootfs-to-image.sh

@@ -88,8 +88,7 @@ create_image_from_sdcard_rootfs() {
 		Called after unmounting both `/root` and `/boot`.
 	POST_UMOUNT_FINAL_IMAGE
 
-	display_alert "Freeing loop device" "${LOOP}"
-	losetup -d "${LOOP}"
+	free_loop_device_insistent "${LOOP}"
 	unset LOOP # unset so cleanup handler does not try it again
 
 	# We're done with ${MOUNT} by now, remove it.

lib/functions/main/rootfs-image.sh

@@ -129,7 +129,7 @@ function trap_handler_cleanup_rootfs_and_image() {
 	# shellcheck disable=SC2153 # global var.
 	if [[ -b "${LOOP}" ]]; then
 		display_alert "Freeing loop" "trap_handler_cleanup_rootfs_and_image ${LOOP}" "wrn"
-		losetup -d "${LOOP}" >&2 || true
+		free_loop_device_insistent "${LOOP}" || true
 	fi
 
 	[[ -d "${SDCARD}" ]] && rm -rf --one-file-system "${SDCARD}"