#!/sbin/runscript
# Copyright 1999-2008 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

description="Save device nodes to a persistent tarball"

depend()
{
	before mount-ro killprocs
}

start() {
	/lib/udev/move_tmp_persistent_rules.sh
	tarball_file=/lib/udev/state/devices.tar.bz2
	if [ -e /etc/conf.d/udev ]
	then
		. /etc/conf.d/udev
	fi
	device_tarball=${device_tarball:-${RC_DEVICE_TARBALL:-NO}}
	if ! yesno "${device_tarball}"
	then
		ebegin "udev: Device tarball disabled, skipping"
		eend 0
		return 0
	fi
	ebegin "Saving device nodes"
	if ! touch "${tarball_file}"
	then
		eend 1 "udev: Couldn't write to device tarball."
		return 1
	fi
	if [ -e /dev/.devfsd ] || [ ! -e /dev/.udev ] 
	then
		eend 1 "udev: Device tarball enabled but udev filesystem not found"
	fi

	# Handle our temp files
	save_tmp_base=/tmp/udev.savedevices."$$"
	devices_udev="${save_tmp_base}"/devices.udev
	devices_real="${save_tmp_base}"/devices.real
	devices_totar="${save_tmp_base}"/devices.totar
	device_tmp_tarball="${save_tmp_base}"/devices
	
	rm -rf "${save_tmp_base}"
	mkdir "${save_tmp_base}"
	touch "${devices_udev}" "${devices_real}" "${devices_totar}" "${device_tmp_tarball}"

	if ! [ -f "${devices_udev}" -a -f "${devices_real}" -a -f "${devices_totar}" -a -f "${device_tmp_tarball}" ]
	then
		eend 1 "udev: Couldn't create temporary files for device tarball"
		return 1
	fi

	cd /dev
	# Find all devices, but ignore .udev directory
	find . -xdev -type b -or -type c -or -type l | cut -d/ -f2- | grep -v ^\\.udev >"${devices_real}"
	
	# Figure out what udev created
	udevadm info --export-db | sed -ne 's,^[SN]: \(.*\),\1,p' >"${devices_udev}"

	# These ones we also do not want in there
	for x in MAKEDEV core fd initctl pts shm stderr stdin stdout root; do
		echo "${x}" >> "${devices_udev}"
	done
	if [ -d /lib/udev/devices ]; then
		cd /lib/udev/devices
		find . -xdev -type b -or -type c -or -type l | cut -d/ -f2- >> "${devices_udev}"
		cd /dev
	fi

	fgrep -x -v -f "${devices_udev}" "${devices_real}" > "${devices_totar}"

	# Now only tarball those not created by udev if we have any
	if [ -s "${devices_totar}" ]; then
		# we dont want to descend into mounted filesystems (e.g. devpts)
		# looking up username may involve NIS/network
		# and net may be down
		tar --one-file-system --numeric-owner -jcpf "${device_tmp_tarball}" -T "${devices_totar}"
		mv -f "${device_tmp_tarball}" "${tarball_file}"
	else
		rm -f "${tarball_file}"
	fi
	eend 0
	einfo "udev: Device tarball created."
}
