main/openrc: refactor modloop to not depend on alpine_dev boot opt

We scan all relevant mount points for the modloop specified with the
modloop boot option. If modloop boot option is missing, then we warn
about it, look for files that blkid recognizes, try mount them and then
look for modules/$(uname -r).

Wen unmounting, find the loop device, and the backing_file and the
mountpoint that holds the backing file.

2 files changed, 66 insertions, 89 deletions

diff --git a/main/openrc/APKBUILD b/main/openrc/APKBUILD
index bcd561f10f..cc45966028 100644
--- a/main/openrc/APKBUILD
+++ b/main/openrc/APKBUILD
@@ -2,7 +2,7 @@
 pkgname=openrc
 pkgver=0.18.3
 _ver=${pkgver/_git*/}
-pkgrel=0
+pkgrel=1
 pkgdesc="OpenRC manages the services, startup and shutdown of a host"
 url="http://git.overlays.gentoo.org/gitweb/?p=proj/openrc.git"
 arch="all"
@@ -88,7 +88,7 @@ d83df5513f08f09fa9e7353327701bf7  openrc.logrotate
 887eba592d487d6ffe2b42cfcd2813df  hwdrivers.initd
 41974f5408fd2e92892f891b58f2e49f  keymaps.initd
 0ece77eff8f163b36f6f0e7a6d422866  modules.initd
-a76e20fe5abea4449ed4e560a11334a4  modloop.initd
+ddf2204a61d3230a3bc51a4e4f0af394  modloop.initd
 27c22aa4e5cdba499ac9a0b6b9385f7d  networking.initd
 c1ec888202d868710b5749f7b217d1e3  modloop.confd
 bd51c5353d6dbbb34d929bf59097b232  consolefont.initd
@@ -106,7 +106,7 @@ e23db45e9399dab96d6c922af6c0cd6c243bbcc43756c845b70a9c7222a96313  hostname.initd
 6cb4d9ea3ad562bcf2697f61f5a76a10481d23f5dead570f82eff576eaca5236  hwdrivers.initd
 32562d39ade4092df8163c2e8cf0b31eeec06aa5713d343e1c487bfa6d9f7c84  keymaps.initd
 a145636e84547d76b8a188a94c0a76fcc266cd0f486be6cf24d2d74f03038118  modules.initd
-61fb9e41c28f3632cc47e4ebd12fa856d0f80803aca1cd3446de3522829f308f  modloop.initd
+fbbcd903601dde931d25c5b9a37859b3c7289673b820865cd1f0cc8a39e3cadf  modloop.initd
 66151b5cc199485ddd188528a0f22f081994721f04c15b33df38f41a5d08ea78  networking.initd
 a5a0316cd59f5401b1d789bb466c98186201277ba6f014017b14965fcc10c254  modloop.confd
 8a3f663e9ac14f62c3aef4121736a71edd676bdc9dd93c1d411f13a0e7ab4ee6  consolefont.initd
@@ -124,7 +124,7 @@ a6e2b44dd548a2470971a44b61ddaaec037438050fe3411b4ea3fe5d36e9ad4cf5b5e226f8d4aacb
 b51d95df7b692aaea3e14ed009d99b46b82500d505e2eeecb6a20136cee140aea4a7377a65ccc5c51fff64be7a50666be48616d179888eaeff9d35178a7a772b  hwdrivers.initd
 584ecbbcecb284527d7616790b6e337ace610e4b3cedf2993eca294bfbef54674aeaee3078b6c17d746a0c48b5a64a813c3534136915947e6f62a6fa206cd3ca  keymaps.initd
 7702e2704e4bcfad7c0736eec4cb0e8b20a685851afb5bd9022c5056ea78b8598a9402bae9644ae3268e2ff1c566e147cbb8d00e143491841682e4125fde2a75  modules.initd
-992fbeded59679963a8d0154415c44949c7cd9719d85190ff57b3cf9db00c1daac090e1f45580cbf446e4d8fb65d21209d529e5709eb27ea2ecc31d75245f969  modloop.initd
+bf9f40a8f65816a2f4ba4856120bac31d6f21d5f0997e1dbe62864bb707466bb2a2844b0a95dee05b0580527a008465613bc923b9419d24f531a80ca8c211e4c  modloop.initd
 9aeba2c5cae539f16185b82c6e6e84c1b044e838749b92e8994172296d86ec3f1c674d62d54db1e08a8191e513ddb0ab3509f50ccae6cb5d7ba5ff5a5b6abb46  networking.initd
 aa702a7da8e6c0e5d8738febaf6b4e4cb021b30ce5c1809b530abf2b36739079446b16fc054740da8d86ed099942cf5deed6597cedb64c058f3def587a8b4689  modloop.confd
 c8d52d69692a00862cd55719174d7a260d5149f4951dd71196f5e9cebce3a75420a8815f0fe8b186d00b4d46739dc54542dae01a941605fcb1435f4385e444b7  consolefont.initd
diff --git a/main/openrc/modloop.initd b/main/openrc/modloop.initd
index 2e7331be11..6bd2e8a2f5 100644
--- a/main/openrc/modloop.initd
+++ b/main/openrc/modloop.initd
@@ -11,115 +11,89 @@ depend() {
 # read kernel options
 init_KOPT() {
 	eval set -- $(cat /proc/cmdline 2>/dev/null)
-	# in case syslinux does not set BOOT_IMAGE
-	KOPT_BOOT_IMAGE="${1}"
 	for opt; do
 	        case "$opt" in
-			alpine_dev=*|modloop=*|BOOT_IMAGE=*)
+			modloop=*)
 				eval "KOPT_${opt%%=*}='${opt#*=}'" ;;
-        	esac
+		esac
 	done
 }
 
-resolve_dev() {
-	case "$1" in
-	UUID=*|LABEL=*) findfs "$1";;
-	*) readlink -f "$1";;
-	esac
+mountdirs() {
+	awk '$2 !~ /^\/(sys|proc|dev|run)/ && $2 != "/" {print $2}' /proc/mounts
 }
 
-find_mnt() {
-	local search_dev="$1" fstab="$2"
-	local dev mnt fs mntopts chk
-	case "$search_dev" in
-		UUID=*|LABEL=*|/dev/*);;
-		nfs) search_dev="${KOPT_alpine_dev#nfs:}";;
-		*) search_dev=/dev/$search_dev;;
-	esac
-	local search_real_dev=$(resolve_dev $search_dev)
-	while read dev mnt fs mntopts chk; do
-		local real_dev=$(resolve_dev $dev)
-		local i j
-		for i in "$search_dev" "$search_real_dev"; do
-			[ -z "$i" ] && continue
-			for j in "$dev" "$real_dev"; do
-				[ -z "$j" ] && continue
-				if [ "$i" = "$j" ]; then
-					echo "$mnt"
-					return
-				fi
-			done
-		done
-	done < $fstab 2>/dev/null
+find_modloop() {
+	local dir="$1"
+	local kver=$(uname -r)
+	local oifs="$IFS"
+	IFS=$'\n'
+	set -- $(blkid "$dir"/boot/* "$dir"/*)
+	IFS="$oifs"
+	for line; do
+		img=${line%%:*}
+		mount "$img" -o loop,ro /.modloop || continue
+		if [ -d /.modloop/modules/$kver ]; then
+			return 0
+		fi
+		umount /.modloop
+	done
+	return 1
 }
 
-# initialies: alpine_dev, alpine_mnt, alpine_fs, alpine_mounted
-find_media() {
-	init_KOPT
-	[ -z "$KOPT_alpine_dev" ] && return 0
-	alpine_mounted=
-	alpine_dev=${KOPT_alpine_dev%%:*}
-	alpine_fs=${KOPT_alpine_dev#*:}
-	[ "$alpine_fs" = "$KOPT_alpine_dev" ] && unset alpine_fs
-	# first we check if alpine_dev is mounted and use this
-	alpine_mnt=$(find_mnt $alpine_dev /proc/mounts)
-	if [ -z "$alpine_mnt" ]; then
-		# then we check fstab
-		alpine_mnt=$(find_mnt $alpine_dev /etc/fstab)
-	else
-		alpine_mounted=yes
+find_backing_file() {
+	local dir="$1"
+	local dev=$(df -P "$dir" | tail -1 | awk '{print $1}')
+	cat /sys/block/${dev#/dev/}/loop/backing_file 2>/dev/null
+}
+
+find_alpine_mnt() {
+	local img="$(find_backing_file $1)"
+	if [ -n "$img" ]; then
+		df -P "$img" | tail -1 | awk '{print $6}'
 	fi
-	# finally we fallback to /media/<devicename>
-	[ -z "$alpine_mnt" ] && alpine_mnt=/media/$alpine_dev
 }
 
 start() {
 	local modloop= mount_opts= modloop_dldir="/lib"
 
-	find_media
-
+	mkdir -p /.modloop /lib
 	case "$KOPT_modloop" in
 		http://*|https://|ftp://*)
 			wget -P "$modloop_dldir" "$KOPT_modloop" \
 				&& modloop=$modloop_dldir/$(basename $KOPT_modloop)
 			;;
+		"")
+			ewarn "WARNING! modloop boot option is missing."
+			;;
 		*)
-			if [ -z "$alpine_dev" ]; then
-				return 0
-			fi
-			if [ -z "$alpine_mounted" ]; then
-				ebegin "Mounting $alpine_mnt"
-				[ -n "$alpine_fs" ] && mount_opts="-t $alpine_fs"
-				mount $mount_opts /dev/$alpine_dev $alpine_mnt 2>/dev/null
-				eend $? || return 1
-			fi
-
-			bootimagedir=${KOPT_BOOT_IMAGE%/*}
-			bootdir=${alpine_mnt}${bootimagedir}
-			kver=$(uname -r)
-			case $kver in
-			*-rc[0-9]) kflavor=vanilla;;
-			*-[a-z]*)  kflavor=${kver##*-};;
-			*)         kflavor=vanilla;;
-			esac
-			for modloop in ${alpine_mnt}$KOPT_modloop \
-				${bootdir}/modloop-$kver \
-				${bootdir}/modloop-$kflavor \
-				${bootdir}/modloop \
-				${alpine_mnt}/boot/modloop-$kver \
-				${alpine_mnt}/boot/modloop-$kflavor \
-				${alpine_mnt}/boot/modloop \
-				${alpine_mnt}$KOPT_BOOT_IMAGE.modloop.*; do
-
-				[ -f "$modloop" -o -n "$KOPT_modloop" ] && break
+			for dir in $(mountdirs); do
+				if [ -f "$dir"/$KOPT_modloop ]; then
+					modloop="$dir/${KOPT_modloop##/}"
+					alpine_mnt="$dir"
+					break
+				fi
 			done
 			;;
 	esac
 
 	ebegin "Mounting modloop $modloop"
-	mkdir -p /.modloop /lib
-	mount -o loop,ro $fs_opt $modloop /.modloop
-	eend $? || return 1
+	if [ -n "$modloop" ]; then
+		mount -o loop,ro $modloop /.modloop
+		eend $? || return 1
+	else
+		for dir in $(mountdirs); do
+			if find_modloop "$dir"; then
+				alpine_mnt="$dir"
+				break
+			fi
+		done
+		if [ -d /.modloop/modules/$(uname -r) ]; then
+			eend 0
+		else
+			eend 1 || return 1
+		fi
+	fi
 
 	#use unionfs is available and configured
 	if grep -q -w "unionfs$" /proc/filesystems && [ -n "$unionfs_size" ]; then
@@ -146,14 +120,17 @@ start() {
 
 stop() {
 	local rc=0
-	find_media
-	[ -z "$alpine_dev" ] && return 0
+	alpine_mnt=$(find_alpine_mnt /.modloop)
+	if mountinfo --quiet /.modunisonfs/modules && mountinfo --quiet /lib/modules; then
+		umount /lib/modules
+		umount /.modunisonfs/modules
+	fi
 	if mountinfo --quiet /.modloop; then
 		ebegin "Unmounting /.modloop"
 		umount -d /.modloop
 		eend $? || return 1
 	fi
-	if mountinfo --quiet $alpine_mnt; then
+	if [ -n "$alpine_mnt" ] && mountinfo --quiet $alpine_mnt; then
 		ebegin "Unmounting $alpine_mnt"
 		umount $alpine_mnt
 		eend $?