#!/bin/sh -e
### BEGIN INIT INFO
# Provides: udev
# Required-Start: mountkernfs
# Required-Stop:
# Default-Start: S
# Default-Stop:
# Short-Description: Start udevd, populate /dev and load drivers.
### END INIT INFO

# we need to unmount /dev/pts/ and remount it later over the devtmpfs
unmount_devpts() {
if mountpoint -q /dev/pts/; then
umount -n -l /dev/pts/
fi

if mountpoint -q /dev/shm/; then
umount -n -l /dev/shm/
fi
}

# mount a devtmpfs over /dev, if somebody did not already do it
mount_devtmpfs() {
if grep -E -q "^[^[:space:]]+ /dev devtmpfs" /proc/mounts; then
mount -n -o remount,size=$tmpfs_size,mode=0755 -t devtmpfs devtmpfs /dev
return
fi

if ! mount -n -o size=$tmpfs_size,mode=0755 -t devtmpfs devtmpfs /dev; then
log_failure_msg "udev requires devtmpfs support, not started"
log_end_msg 1
fi

return 0
}

create_dev_makedev() {
if [ -e /sbin/MAKEDEV ]; then
ln -sf /sbin/MAKEDEV /dev/MAKEDEV
else
ln -sf /bin/true /dev/MAKEDEV
fi
}

# If the initramfs does not have /run, the initramfs udev database must
# be migrated from /dev/.udev/ to /run/udev/.
move_udev_database() {
[ -e "/dev/.udev/" ] || return 0
[ ! -e /run/udev/ ] || return 0
[ -e /run/ ] || return 0
mountpoint -q /run/ || return 0

mv /dev/.udev/ /run/udev/ || true
}

supported_kernel() {
case "$(uname -r)" in
2.[012345].*|2.6.[0-9]|2.6.[0-9][!0-9]*) return 1 ;;
2.6.[12][0-9]|2.6.[12][0-9][!0-9]*) return 1 ;;
2.6.3[0-1]|2.6.3[0-1][!0-9]*) return 1 ;;
esac
return 0
}

# shell version of /usr/bin/tty
my_tty() {
[ -x /bin/readlink ] || return 0
[ -e /proc/self/fd/0 ] || return 0
readlink --silent /proc/self/fd/0 || true
}

warn_if_interactive() {
if [ "$RUNLEVEL" = "S" -a "$PREVLEVEL" = "N" ]; then
return
fi

TTY=$(my_tty)
if [ -z "$TTY" -o "$TTY" = "/dev/console" -o "$TTY" = "/dev/null" ]; then
return
fi

printf "\n\n\nIt has been detected that the command\n\n\t$0 $*\n\n"
printf "has been run from an interactive shell.\n"
printf "It will probably not do what you expect, so this script will wait\n"
printf "60 seconds before continuing. Press ^C to stop it.\n"
printf "RUNNING THIS COMMAND IS HIGHLY DISCOURAGED!\n\n\n\n"
sleep 60
}

##############################################################################

[ -x /sbin/udevd ] || exit 0

PATH="/sbin:/bin"

# defaults
tmpfs_size="10M"

if [ -e /etc/udev/udev.conf ]; then
. /etc/udev/udev.conf
fi

. /lib/lsb/init-functions

if ! supported_kernel; then
log_failure_msg "udev requires a kernel >= 2.6.32, not started"
log_end_msg 1
fi

if [ ! -e /proc/filesystems ]; then
log_failure_msg "udev requires a mounted procfs, not started"
log_end_msg 1
fi

if ! grep -q '[[:space:]]devtmpfs$' /proc/filesystems; then
log_failure_msg "udev requires devtmpfs support, not started"
log_end_msg 1
fi

if [ ! -d /sys/class/ ]; then
log_failure_msg "udev requires a mounted sysfs, not started"
log_end_msg 1
fi

if [ ! -e /sys/kernel/uevent_helper ]; then
log_failure_msg "udev requires hotplug support, not started"
log_end_msg 1
fi

if ! ps --no-headers --format args ax | egrep -q '^\['; then
log_warning_msg "udev does not support containers, not started"
exit 0
fi

if [ -d /sys/class/mem/null -a ! -L /sys/class/mem/null ] || \
[ -e /sys/block -a ! -e /sys/class/block ]; then
log_warning_msg "CONFIG_SYSFS_DEPRECATED must not be selected"
log_warning_msg "Booting will continue in 30 seconds but many things will be broken"
sleep 30
fi

# When modifying this script, do not forget that between the time that the
# new /dev has been mounted and udevadm trigger has been run there will be
# no /dev/null. This also means that you cannot use the "&" shell command.

case "$1" in
start)
if init_is_upstart 2>/dev/null; then
exit 1
fi
if mountpoint -q /dev/; then
TMPFS_MOUNTED=1
elif [ -e "/dev/.udev/" ]; then
log_warning_msg ".udev/ already exists on the static /dev"
fi

if [ ! -e "/dev/.udev/" -a ! -e "/run/udev/" ]; then
warn_if_interactive
fi

echo > /sys/kernel/uevent_helper

move_udev_database

if [ -z "$TMPFS_MOUNTED" ]; then
unmount_devpts
mount_devtmpfs
[ -d /proc/1 ] || mount -n /proc
fi

# clean up parts of the database created by the initramfs udev
udevadm info --cleanup-db

# set the SELinux context for devices created in the initramfs
[ -x /sbin/restorecon ] && /sbin/restorecon -R /dev

# /dev/null must be created before udevd is started
/lib/udev/create_static_nodes || true

log_daemon_msg "Starting the hotplug events dispatcher" "udevd"
if udevd --daemon; then
log_end_msg $?
else
log_warning_msg $?
log_warning_msg "Waiting 15 seconds and trying to continue anyway"
sleep 15
fi

log_action_begin_msg "Synthesizing the initial hotplug events"
if udevadm trigger --action=add; then
log_action_end_msg $?
else
log_action_end_msg $?
fi

create_dev_makedev

# wait for the udevd childs to finish
log_action_begin_msg "Waiting for /dev to be fully populated"
if udevadm settle; then
log_action_end_msg 0
else
log_action_end_msg 0 'timeout'
fi
;;

stop)
log_daemon_msg "Stopping the hotplug events dispatcher" "udevd"
if start-stop-daemon --stop --name udevd --user root --quiet --oknodo --retry 5; then
log_end_msg $?
else
log_end_msg $?
fi
;;

restart)
if init_is_upstart 2>/dev/null; then
exit 1
fi
log_daemon_msg "Stopping the hotplug events dispatcher" "udevd"
if start-stop-daemon --stop --name udevd --user root --quiet --oknodo --retry 5; then
log_end_msg $?
else
log_end_msg $? || true
fi

log_daemon_msg "Starting the hotplug events dispatcher" "udevd"
if udevd --daemon; then
log_end_msg $?
else
log_end_msg $?
fi
;;

reload|force-reload)
udevadm control --reload-rules
;;

status)
status_of_proc /sbin/udevd udevd && exit 0 || exit $?
;;

*)
echo "Usage: /etc/init.d/udev {start|stop|restart|reload|force-reload|status}" >&2
exit 1
;;
esac

exit 0