Make sysfs behave like netmount and localmount

sysfs now mounts all related sysfs file systems and returns success,
like netmount and localmount.

Also, we now check to make sure the cgroups are not mounted before we
mount them.

X-Gentoo-Bug: 530138
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=530138

init.d/sysfs.in

@@ -113,7 +113,8 @@ mount_cgroups()
 	yesno ${rc_controller_cgroups:-YES} && [ -e /proc/cgroups ] || return 0
 	while read name hier groups enabled rest; do
 		case "${enabled}" in
-			1)	mkdir /sys/fs/cgroup/${name}
+			1)	mountinfo -q /sys/fs/cgroup/${name} && continue
+				mkdir /sys/fs/cgroup/${name}
 				mount -n -t cgroup -o ${sysfs_opts},${name} \
 					${name} /sys/fs/cgroup/${name}
 				;;
@@ -129,25 +130,13 @@ restorecon_sys()
 		restorecon -rF /sys/fs/cgroup >/dev/null 2>&1
 		eend $?
 	fi
-
-	return 0
 }
 
 start()
 {
-	local retval
 	mount_sys
-	retval=$?
-	if [ $retval -eq 0 ]; then
-		mount_misc
-		retval=$?
-	fi
-	if [ $retval -eq 0 ]; then
-		mount_cgroups
-		retval=$?
-	fi
-
+	mount_misc
+	mount_cgroups
 	restorecon_sys
-
-	return $retval
+	return 0
 }