From 1377e903b864673138908165572a18933400e8eb Mon Sep 17 00:00:00 2001
From: Vasilis Tsiligiannis <acinonyx@openwrt.gr>
Date: Thu, 4 Jan 2024 13:05:51 +0200
Subject: [PATCH] Ensure loop device partition nodes are created (#741)

Although the loop block device is created before attaching the image
to it, the devices for the partition that the image contains are still
not created. This patch creates those devices as well, when they are
not already available.

Fixes #482

Signed-off-by: Vasilis Tsiligiannis <acinonyx@openwrt.gr>
---
 export-image/prerun.sh |  1 +
 export-noobs/prerun.sh |  1 +
 scripts/common         | 14 ++++++++++++++
 3 files changed, 16 insertions(+)

diff --git a/export-image/prerun.sh b/export-image/prerun.sh
index a5f94e9..d042c6a 100755
--- a/export-image/prerun.sh
+++ b/export-image/prerun.sh
@@ -46,6 +46,7 @@ if [ "${NO_PRERUN_QCOW2}" = "0" ]; then
 		fi
 	done
 
+	ensure_loopdev_partitions "$LOOP_DEV"
 	BOOT_DEV="${LOOP_DEV}p1"
 	ROOT_DEV="${LOOP_DEV}p2"
 
diff --git a/export-noobs/prerun.sh b/export-noobs/prerun.sh
index 6282836..80cbb8e 100755
--- a/export-noobs/prerun.sh
+++ b/export-noobs/prerun.sh
@@ -22,6 +22,7 @@ until ensure_next_loopdev && LOOP_DEV="$(losetup --show --find --partscan "$IMG_
 	fi
 done
 
+ensure_loopdev_partitions "$LOOP_DEV"
 BOOT_DEV="${LOOP_DEV}p1"
 ROOT_DEV="${LOOP_DEV}p2"
 
diff --git a/scripts/common b/scripts/common
index 74c7938..cda5551 100644
--- a/scripts/common
+++ b/scripts/common
@@ -110,3 +110,17 @@ ensure_next_loopdev() {
 	[[ -b "$loopdev" ]] || mknod "$loopdev" b 7 "$loopmaj"
 }
 export -f ensure_next_loopdev
+
+ensure_loopdev_partitions() {
+	local line
+	local partition
+	local majmin
+	lsblk -r -n -o "NAME,MAJ:MIN" "$1" | grep -v "^${1#/dev/} " | while read -r line; do
+		partition="${line%% *}"
+		majmin="${line#* }"
+		if [ ! -b "/dev/$partition" ]; then
+			mknod "/dev/$partition" b "${majmin%:*}" "${majmin#*:}"
+		fi
+	done
+}
+export -f ensure_loopdev_partitions