Use timeout from coreutils
--- a/lib/rc/sh/rc-mount.sh	2013-02-04 15:06:20.492478073 +0100
+++ b/lib/rc/sh/rc-mount.sh	2013-02-05 11:17:17.013606599 +0100
@@ -41,7 +41,8 @@
 		retry=4 # Effectively TERM, sleep 1, TERM, sleep 1, KILL, sleep 1
 		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)"
+				timeout=60
+				pids="$(timeout -s KILL -k 10 "$timeout" fuser $f_opts "$mnt" 2>/dev/null)"
 			fi
 			case " $pids " in
 				*" $$ "*)