openrc/sh/rc-mount.sh

# Copyright 2007-2009 Roy Marples <roy@marples.name>
# All rights reserved. Released under the 2-clause BSD license.

# Declare this here so that no formatting doesn't affect the embedded newline
__IFS="
"

# Handy function to handle all our unmounting needs
# mountinfo is a C program to actually find our mounts on our supported OS's
# We rely on fuser being present, so if it's not then don't unmount anything.
# This isn't a real issue for the BSD's, but it is for Linux.
do_unmount()
{
	local cmd="$1" retval=0 retry= pids=-
	local f_opts="-m -c" f_kill="-s " mnt=
	if [ "$RC_UNAME" = "Linux" ]; then
		f_opts="-m"
		f_kill="-"
	fi

	shift
	local IFS="$__IFS"
	set -- $(mountinfo "$@")
	unset IFS
	for mnt; do
		# Unmounting a shared mount can unmount other mounts, so
		# we need to check the mount is still valid
		mountinfo --quiet "$mnt" || continue

		case "$cmd" in
			umount)
				ebegin "Unmounting $mnt"
				;;
			*)
				ebegin "Remounting $mnt read only"
				;;
		esac

		retry=3
		while ! LC_ALL=C $cmd "$mnt" 2>/dev/null; do
			if type fuser >/dev/null 2>&1; then
				pids="$(fuser $f_opts "$mnt" 2>/dev/null)"
			fi
			case " $pids " in
				*" $$ "*)
					eend 1 "failed because we are using" \
					"$mnt"
					retry=0;;
				" - ")
					eend 1
					retry=0;;
				"  ")
					eend 1 "in use but fuser finds nothing"
					retry=0;;
				*)
					local sig="KILL"
					[ $retry -gt 0 ] && sig="TERM"
					fuser $f_kill$sig -k $f_opts \
						"$mnt" >/dev/null 2>&1
					sleep 1
					retry=$(($retry - 1))
					[ $retry -le 0 ] && eend 1
					;;
			esac
			[ $retry -le 0 ] && break
		done
		if [ $retry -le 0 ]; then
			retval=1
		else
			eend 0
		fi
	done
	return $retval
}