mars/contrib/sysvinit/mars

#!/bin/sh
### BEGIN INIT INFO
# Provides:          mars
# Required-Start:    $network $local_fs $remote_fs
# Required-Stop:     $remote_fs
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: MARS module/userspace control
# Description:       This script loads/unloads the MARS kernel module
### END INIT INFO

# Author: Daniel Hermann <daniel.hermann@1und1.de>

# PATH should only include /usr/* if it runs after the mountnfs.sh script
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC=MARS
NAME=mars
MODULE=mars
SCRIPTNAME=/etc/init.d/$NAME
ENABLED="true"

MODPROBE=/sbin/modprobe
RMMOD=/sbin/rmmod
SYSCTL=/sbin/sysctl

MODPROBE_PARAMS="-s"
RMMOD_PARAMS="-s"

MOUNT_FROM_FSTAB="true"
MARS_MOUNTPOINT="/mars"
MOUNT_OPTIONS=""
SYSCTL_CONFFILE=/etc/mars/sysctl.conf

## Enable read ahead for /mars by setting following parameter in kB
## Reasonable value: 256 (kB)
READAHEAD_FOR_MARS_DEVICE=

# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME

# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh

# Define LSB log_* functions.
# Depend on lsb-base (>= 3.0-6) to ensure that this file is present.
. /lib/lsb/init-functions

mount_mars_from_fstab()
{
    if [ "$MOUNT_FROM_FSTAB" = "true" ]; then
	if grep -q " $MARS_MOUNTPOINT " /proc/mounts; then
	    log_progress_msg "($MARS_MOUNTPOINT already mounted)"
	    return 1
	fi
	log_progress_msg "(mount $MARS_MOUNTPOINT)"
	mount $MOUNT_OPTIONS $MARS_MOUNTPOINT || return 2
    else
	# MOUNT_FROM_FSTAB is disabled and we have no
	log_progress_msg "($MARS_MOUNTPOINT not mounted)"
        # ignore this "error", /mars may be on root partition
	return 0
    fi
}

umount_mars()
{
    if [ "$MOUNT_FROM_FSTAB" = "true" ]; then
	if ! grep -q " $MARS_MOUNTPOINT " /proc/mounts; then
	    log_progress_msg "($MARS_MOUNTPOINT not mounted)"
	    return 1
	else
	    log_progress_msg "(umount $MARS_MOUNTPOINT)"
	    umount $MARS_MOUNTPOINT || return 2
	fi
    fi
}

load_module()
{
    if [ -r /sys/module/mars/version ]; then
	log_progress_msg "(module already loaded)"
	return 1    # already loaded
    fi

    if ! modinfo mars >/dev/null; then
	log_progress_msg "(module unavailable)"
	return 2
    fi

    log_progress_msg "(load module)"

    $MODPROBE $MODPROBE_PARAMS mars || return 2

    # Set custom kernel parameters after module is loaded
    if [ -s $SYSCTL_CONFFILE ]; then
        log_progress_msg "(sysctl $SYSCTL_CONFFILE)"
        $SYSCTL -q -p $SYSCTL_CONFFILE || return 2
    fi

}

unload_module()
{
    if [ ! -r /sys/module/mars/version ]; then
	log_progress_msg "(module not loaded)"
	return 1
    fi

    log_progress_msg "(unload module)"

    $RMMOD $RMMOD_PARAMS mars || return 2
}

set_readahead()
{
    local rc=0
    if [ $READAHEAD_FOR_MARS_DEVICE ]; then
	MARS_DEV_LINK=/dev/disk/by-label/mars
	if [ ! -L ${MARS_DEV_LINK} ]; then
	    errmsg=" NOLABEL"
	    rc=2
	else
	    MARS_DEV=$( readlink -e ${MARS_DEV_LINK} )
	    if [ $? -ne 0 ]; then
		errmsg=" NODEV"
		rc=2
	    else
		MARS_DEV=${MARS_DEV##*/}  # remove prefix
		READAHEAD_SYSFILE=/sys/block/$MARS_DEV/queue/read_ahead_kb
		if [ ! -w $READAHEAD_SYSFILE ]; then
		    errmsg=" NOSYSFILE"
		    rc=2
		fi
	    fi
	fi
	log_progress_msg "(set readahead ${READAHEAD_FOR_MARS_DEVICE}kB for $MARS_DEV$errmsg)"
	if [ $rc -eq 0 ]; then
	    echo ${READAHEAD_FOR_MARS_DEVICE} > $READAHEAD_SYSFILE
	fi
    fi
    return $rc
}

do_start()
{
    mount_mars_from_fstab; rc1=$?
    case "$rc1" in
	0|1)  set_readahead; rc2=$? ;;
	*)  rc2=255 ;;
    esac
    case "$rc1" in   # ignore failures of set_readahead
	0|1)  load_module; rc3=$? ;;
	*)  rc3=255 ;;
    esac
    case "$rc3" in
	0|1)  return $(( rc1 * rc3 )) ;;
	*)    return 2
    esac
}

do_stop()
{
    if marsadm show all | grep -q actual-$(uname -n)/is-primary\=1; then
	log_progress_msg "(local node is primary for some resource)"
	return 2
    fi
    unload_module; rc1=$?
    case "$rc1" in
	0|1)  umount_mars; rc2=$? ;;
	2)  rc2=255 ;;
    esac
    case "$rc2" in
	0|1)  return $(( rc1 * rc2 )) ;;
	*)    return 2
    esac
}

do_status()
{
    if [ -r /sys/module/mars/version ]; then
	MODVERS=$(cat /sys/module/mars/version)
	echo "module is loaded: $MODVERS"
	return 0  # LSB: running
    else
	echo -n "module NOT loaded, "
	if grep -q " $MARS_MOUNTPOINT " /proc/mounts; then
	    echo "$MARS_MOUNTPOINT is mounted"
	else
	    echo "$MARS_MOUNTPOINT NOT mounted"
	fi
	return 3  # LSB: not running
    fi
}

case "$1" in
  start)
	if [ "$ENABLED" = "true" ]; then
	    [ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC "
	    do_start
	    case "$?" in
		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
	    esac
	else
	    log_warning_msg "$DESC not enabled in /etc/default/$NAME, not starting."
	fi
	;;
  stop)
	[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC"
	do_stop
	case "$?" in
	    0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
	    2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
	esac
	;;
  status)
	do_status
	exit $?
	;;
  restart|force-reload)
	if [ "$ENABLED" = "true" ]; then
	    log_daemon_msg "Restarting $DESC"
	    do_stop
	    case "$?" in
		0|1)
		    do_start
		    case "$?" in
			0) log_end_msg 0 ;;
			1) log_end_msg 1 ;; # module never was sucessfully unloaded
			*) log_end_msg 1 ;; # failed to load module
		    esac
		    ;;
		*)
		    # failed to unload
		    log_end_msg 1
		    ;;
	    esac
	else
	    log_warning_msg "$DESC not enabled in /etc/default/$NAME, not starting."
	fi
	;;
  *)
	echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
	exit 3
	;;
esac

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