#!/sbin/openrc-run
# Copyright (c) 2017 The OpenRC Authors.
# See the Authors file at the top-level directory of this distribution and
# https://github.com/OpenRC/openrc/blob/HEAD/AUTHORS
#
# This file is part of OpenRC. It is subject to the license terms in
# the LICENSE file found in the top-level directory of this
# distribution and at https://github.com/OpenRC/openrc/blob/HEAD/LICENSE
# This file may not be copied, modified, propagated, or distributed
# except according to the terms contained in the LICENSE file.

description="Mount the control groups."

cgroup_opts=nodev,noexec,nosuid

depend()
{
	keyword -docker -prefix -systemd-nspawn -vserver
	after sysfs
}

cgroup1_base()
{
	grep -qw cgroup /proc/filesystems || return 0
	if ! mountinfo -q /sys/fs/cgroup; then
		ebegin "Mounting cgroup filesystem"
		local opts="${cgroup_opts},mode=755,size=${rc_cgroupsize:-10m}"
		mount -n -t tmpfs -o "${opts}" cgroup_root /sys/fs/cgroup
		eend $?
	fi

	if ! mountinfo -q /sys/fs/cgroup/openrc; then
		local agent="${RC_LIBEXECDIR}/sh/cgroup-release-agent.sh"
		mkdir /sys/fs/cgroup/openrc
		mount -n -t cgroup \
			-o none,${cgroup_opts},name=openrc,release_agent="$agent" \
			openrc /sys/fs/cgroup/openrc
		printf 1 > /sys/fs/cgroup/openrc/notify_on_release
	fi
	return 0
}

cgroup1_controllers()
{
	yesno "${rc_controller_cgroups:-YES}" && [ -e /proc/cgroups ]  &&
	grep -qw cgroup /proc/filesystems || return 0
	while read -r name _ _ enabled _; do
		case "${enabled}" in
			1)	mountinfo -q "/sys/fs/cgroup/${name}" && continue
				local x
				for x in $rc_cgroup_controllers; do
				[ "${name}" = "blkio" ] && [ "${x}" = "io" ] &&
					continue 2
				[ "${name}" = "${x}" ] &&
				continue 2
				done
				mkdir "/sys/fs/cgroup/${name}"
				mount -n -t cgroup -o "${cgroup_opts},${name}" \
					"${name}" "/sys/fs/cgroup/${name}"
				yesno "${rc_cgroup_memory_use_hierarchy:-no}" &&
					[ "${name}" = memory ] &&
					echo 1 > /sys/fs/cgroup/memory/memory.use_hierarchy
				;;
		esac
	done < /proc/cgroups
	return 0
}

cgroup2_base()
{
	grep -qw cgroup2 /proc/filesystems || return 0
	local base
	base="$(cgroup2_find_path)"
	mkdir -p "${base}"
	mount -t cgroup2 none -o "${cgroup_opts},nsdelegate" "${base}" 2> /dev/null ||
		mount -t cgroup2 none -o "${cgroup_opts}" "${base}"
	return 0
}

cgroup2_controllers()
{
	grep -qw cgroup2 /proc/filesystems || return 0
	local active cgroup_path x y
	cgroup_path="$(cgroup2_find_path)"
	[ -z "${cgroup_path}" ] && return 0
	[ ! -e "${cgroup_path}/cgroup.controllers" ] && return 0
	[ ! -e "${cgroup_path}/cgroup.subtree_control" ]&& return 0
	read -r active < "${cgroup_path}/cgroup.controllers"
	for x in ${active}; do
	case "$rc_cgroup_mode" in
		unified)
			echo "+${x}"  > "${cgroup_path}/cgroup.subtree_control"
			;;
		hybrid)
			for y in ${rc_cgroup_controllers}; do
				if [ "$x" = "$y" ]; then
					echo "+${x}"  > "${cgroup_path}/cgroup.subtree_control"
				fi
			done
			;;
		esac
	done
	return 0
}

cgroups_hybrid()
{
	cgroup1_base
	cgroup2_base
	cgroup2_controllers
	cgroup1_controllers
	return 0
}

cgroups_legacy()
{
	cgroup1_base
	cgroup1_controllers
	return 0
}

cgroups_unified()
{
	cgroup2_base
	cgroup2_controllers
	return 0
}

mount_cgroups()
{
	case "${rc_cgroup_mode:-hybrid}" in
	hybrid) cgroups_hybrid ;;
	legacy) cgroups_legacy ;;
	unified) cgroups_unified ;;
	esac
	return 0
}

restorecon_cgroups()
{
	if [ -x /sbin/restorecon ]; then
		ebegin "Restoring SELinux contexts in /sys/fs/cgroup"
		restorecon -rF /sys/fs/cgroup >/dev/null 2>&1
		eend $?
	fi
	return 0
}

start()
{
	# set up kernel support for cgroups
	if [ -d /sys/fs/cgroup ]; then
		mount_cgroups
		restorecon_cgroups
	fi
	return 0
}