etc-gentoo/init.d/sysfs

#!/sbin/openrc-run
# Copyright (c) 2007-2009 Roy Marples <roy@marples.name>
# Released under the 2-clause BSD license.

description="Mount the sys filesystem."

sysfs_opts=nodev,noexec,nosuid

depend()
{
	keyword -lxc -prefix -systemd-nspawn -vserver
}

mount_sys()
{
	grep -Eq "[[:space:]]+sysfs$" /proc/filesystems || return 1
	mountinfo -q /sys && return 0

	if [ ! -d /sys ]; then
		if ! mkdir -m 0755 /sys; then
			ewarn "Could not create /sys!"
			return 1
		fi
	fi

	ebegin "Mounting /sys"
	if ! fstabinfo --mount /sys; then
		mount -n -t sysfs -o ${sysfs_opts} sysfs /sys
	fi
	eend $?
}

mount_misc()
{
	# Setup Kernel Support for securityfs
	if [ -d /sys/kernel/security ] && \
		! mountinfo -q /sys/kernel/security; then
		if grep -qs securityfs /proc/filesystems; then
			ebegin "Mounting security filesystem"
			mount -n -t securityfs -o ${sysfs_opts} \
				securityfs /sys/kernel/security
			eend $?
		fi
	fi

	# Setup Kernel Support for debugfs
	if [ -d /sys/kernel/debug ] && ! mountinfo -q /sys/kernel/debug; then
		if grep -qs debugfs /proc/filesystems; then
			ebegin "Mounting debug filesystem"
			mount -n -t debugfs -o ${sysfs_opts} debugfs /sys/kernel/debug
			eend $?
		fi
	fi

	# Setup Kernel Support for configfs
	if [ -d /sys/kernel/config ] && ! mountinfo -q /sys/kernel/config; then
		if grep -qs configfs /proc/filesystems; then
			ebegin "Mounting config filesystem"
			mount -n -t configfs -o  ${sysfs_opts} configfs /sys/kernel/config
			eend $?
		fi
	fi

	# set up kernel support for cgroups
	if [ -d /sys/fs/cgroup ] && ! mountinfo -q /sys/fs/cgroup; then
		if grep -qs cgroup /proc/filesystems; then
			ebegin "Mounting cgroup filesystem"
			local opts="${sysfs_opts},mode=755,size=${rc_cgroupsize:-10m}"
			mount -n -t tmpfs -o ${opts} cgroup_root /sys/fs/cgroup
			eend $?
		fi
	fi

	# set up kernel support for fusectl
	if [ -d /sys/fs/fuse/connections ] \
		&& ! mountinfo -q /sys/fs/fuse/connections; then
		if grep -qs fusectl /proc/filesystems; then
			ebegin "Mounting fuse control filesystem"
			mount -n -t fusectl -o ${sysfs_opts} \
				fusectl /sys/fs/fuse/connections
			eend $?
		fi
	fi

	# Setup Kernel Support for SELinux
	if [ -d /sys/fs/selinux ] && ! mountinfo -q /sys/fs/selinux; then
		if grep -qs selinuxfs /proc/filesystems; then
			ebegin "Mounting SELinux filesystem"
			mount -t selinuxfs selinuxfs /sys/fs/selinux
			eend $?
		fi
	fi

	# setup up kernel support for efivarfs
	# slightly complicated, as if it's build as a module but NOT yet loaded,
	# it will NOT appear in /proc/filesystems yet
	if [ -d /sys/firmware/efi/efivars ] \
		&& ! mountinfo -q /sys/firmware/efi/efivars; then
		modprobe -q efivarfs
		if grep -qs efivarfs /proc/filesystems; then
			ebegin "Mounting efivarfs filesystem"
			mount -n -t efivarfs -o ${sysfs_opts} \
				efivarfs /sys/firmware/efi/efivars
			eend $?
		fi
	fi
}

mount_cgroups()
{
	mountinfo -q /sys/fs/cgroup || return 0

	if ! mountinfo -q /sys/fs/cgroup/openrc; then
		local agent="/lib64/rc/sh/cgroup-release-agent.sh"
		mkdir /sys/fs/cgroup/openrc
		mount -n -t cgroup \
			-o none,${sysfs_opts},name=openrc,release_agent="$agent" \
			openrc /sys/fs/cgroup/openrc
		echo 1 > /sys/fs/cgroup/openrc/notify_on_release
	fi

	yesno ${rc_controller_cgroups:-YES} && [ -e /proc/cgroups ] || return 0
	while read name hier groups enabled rest; do
		case "${enabled}" in
			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}
				;;
		esac
	done < /proc/cgroups
}

restorecon_sys()
{
	if [ -x /sbin/restorecon ]; then
		ebegin "Restoring SELinux contexts in /sys"
		restorecon -F /sys/devices/system/cpu/online >/dev/null 2>&1
		restorecon -rF /sys/fs/cgroup >/dev/null 2>&1
		eend $?
	fi
}

start()
{
	mount_sys
	mount_misc
	mount_cgroups
	restorecon_sys
	return 0
}