#! /bin/sh
### BEGIN INIT INFO
# Provides:          umountroot
# Required-Start:
# Required-Stop:
# Should-Stop:       halt reboot kexec
# Default-Start:
# Default-Stop:      0 6
# Short-Description: Mount the root filesystem read-only.
### END INIT INFO

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

. /lib/lsb/init-functions

do_stop () {
	[ "$VERBOSE" = no ] || log_action_begin_msg "Mounting root filesystem read-only"
	# Ask init to re-exec itself before we go down if it has been
	# upgraded this cycle.  It'll lose all its state, but at least
	# it won't hold open files on the root filesystem (lp:#672177).
	if [ -f /var/run/init.upgraded ]
	then
		old_map=$( cat /proc/1/maps )
		map=$old_map
		telinit u || :
		i=0
		timeout=5
		while [ "$map" = "$old_map" ]
		do
			sleep 1
			map=$( cat /proc/1/maps )
			/usr/bin/logger "waiting for init to respawn"
			i=$((i+1))
			if [ $i -eq $timeout ] ; then
				break
			fi
		done

		if [ "$map" = "$old_map" ] ; then
			/usr/bin/logger "FAIL: init failed to respawn in $timeout seconds - unmounting anyway"
		else
			/usr/bin/logger "SUCCESS: init respawned after $i seconds (within $timeout seconds timeout)"
		fi
	fi

	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 / 2>/dev/null \
	|| mount $MOUNT_FORCE_OPT -n -o remount,ro              dummydev / 2>/dev/null \
	|| mount $MOUNT_FORCE_OPT -n -o remount,ro                       /
	ES=$?
	[ "$VERBOSE" = no ] || log_action_end_msg $ES
}

case "$1" in
  start|status)
	# 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

:
