#!/bin/sh
# Copyright 2011 Canonical, Inc
# Author: Serge Hallyn <serge.hallyn@canonical.com>

set -e

# For simplicity this script provides no flexibility

# If cgroup is mounted by fstab, don't run
# Don't get too smart - bail on any uncommented entry with 'cgroup' in it
if grep -v '^#' /etc/fstab | grep -q cgroup; then
	echo "cgroups mounted from fstab, not mounting /sys/fs/cgroup"
	exit 0
fi

# kernel provides cgroups?
if [ ! -e /proc/cgroups ]; then
	exit 0
fi

# Mount /sys/fs/cgroup if not already done
mountpoint -q /sys/fs/cgroup || mount -t tmpfs -o uid=0,gid=0,mode=0755 cgroup /sys/fs/cgroup

# get list of cgroup controllers
for d in `sed -e '1d;s/\([^\t]\)\t.*$/\1/' /proc/cgroups`; do
	mkdir -p /sys/fs/cgroup/$d
	mountpoint -q /sys/fs/cgroup/$d || (mount -n -t cgroup -o $d cgroup /sys/fs/cgroup/$d || rmdir /sys/fs/cgroup/$d || true)
done

exit 0