#! /bin/sh
### BEGIN INIT INFO
# Provides:		  umountroot
# Required-Start:	umountfs
# Required-Stop:	 umountfs
# Default-Start:	 6
# Default-Stop:
# Short-Description: Mount the root filesystem read-only.
### END INIT INFO

PATH=/sbin:/bin
. /lib/init/vars.sh

. /lib/lsb/init-functions

remount_ro () {
	sync
	local MTPT="$1"
	[ "$VERBOSE" = no ] || log_action_begin_msg "Mounting $MTPT filesystem read-only"
	MOUNT_FORCE_OPT=
	[ "$(uname -s)" = "GNU/kFreeBSD" ] && MOUNT_FORCE_OPT=-f
	# This:
	#	 mount -n -o remount,ro /
	# will act on a bind mount of / if there is one.
	# See #339023 and the comment in checkroot.sh
	mount	$MOUNT_FORCE_OPT -n -o remount,ro -t dummytype dummydev $MTPT 2>/dev/null \
	|| mount $MOUNT_FORCE_OPT -n -o remount,ro			  dummydev $MTPT 2>/dev/null \
	|| mount $MOUNT_FORCE_OPT -n -o remount,ro					   $MTPT 2>/dev/null
	ES=$?
	if [ $ES != 0 ]; then
		DEV=
		while read xDEV xMTPT xJUNK;do
			[ "$xMTPT" = "$MTPT" ] || continue
			[ "/${xDEV#/}" = "$xDEV" ] || continue
			DEV="$xDEV"
			break
		done < /proc/mounts
		if [ "$DEV" ]; then
			local TYPE=$(/lib/udev/vol_id -t $DEV 2> /dev/null)
			if [ -z "$TYPE" ]; then
				TYPE=${MOUNT#* $MTPT }
				TYPE=${TYPE%% *}
			fi
			mount $MOUNT_FORCE_OPT -n -o remount,ro -t $TYPE $DEV $MTPT 2>/dev/null || \
			mount $MOUNT_FORCE_OPT -o remount,ro -t $TYPE $DEV $MTPT
			ES=$?
		fi
	fi
	[ "$VERBOSE" = no ] || log_action_end_msg $ES
}

do_stop () {
	# These directories must exist on the root filesystem as they are
	# targets for system mountpoints.  We've just unmounted all other
	# filesystems, so either they are mounted now (in which case the
	# mount point exists) or we can make the mountpoint.
	for dir in /proc /sys /var/run /var/lock; do
		mkdir -p $dir || true
	done
	
	echo "$(sed '1!G;h;$!d' /proc/mounts)" | while read DEV MTPT FSTYPE REST; do
		case "$MTPT" in /proc|/dev|/.dev|/dev/pts|/dev/shm|/proc/*|/sys|/var/run|/var/lock)
			continue
			;;
		esac
		case "$FSTYPE" in 
		  proc|procfs|linprocfs|devfs|sysfs|usbfs|usbdevfs|devpts|tmpfs|rootfs|securityfs)
			continue
			;;
		  *)
			remount_ro "$MTPT"
			if losetup -a|grep -qs "^$DEV:"; then
				blockdev --setro "$DEV" &>/dev/null || true
			fi
			;;
		esac
	done
}

case "$1" in
	start)
		# No-op
		;;
	restart|reload|force-reload)
		echo "Error: argument '$1' not supported" >&2
		exit 3
		;;
	stop)
		do_stop
		;;
	*)
		echo "Usage: $0 start|stop" >&2
		exit 3
		;;
esac

: