#!/bin/sh
#
#
# License:      GNU General Public License (GPL)
# Support:      users@clusterlabs.org
#
# Raid1
#      Description: Manages a Linux software RAID device on a shared storage medium.
#  Original Author: Eric Z. Ayers (eric.ayers@compgen.com)
# Original Release: 25 Oct 2000
#     RAID patches: http://people.redhat.com/mingo/raid-patches/
# Word to the Wise: http://lwn.net/2000/0810/a/raid-faq.php3
#  Sympathetic Ear: mailto:linux-raid@vger.kernel.org
#
# usage: $0 {start|stop|status|monitor|validate-all|usage|meta-data}
#
#
# EXAMPLE config file /etc/raidtab.md0
# This file must exist on both machines!
#
#  raiddev		    /dev/md0
#  raid-level		    1
#  nr-raid-disks	    2
#  chunk-size		    64k
#  persistent-superblock    1
#  #nr-spare-disks	    0
#    device	    /dev/sda1
#    raid-disk     0
#    device	    /dev/sdb1
#    raid-disk     1
#
# EXAMPLE config file /etc/mdadm.conf (for more info:man mdadm.conf)
#
#  DEVICE /dev/sdb1 /dev/sdc1
#  ARRAY /dev/md0 UUID=4a865b55:ba27ef8d:29cd5701:6fb42799
#######################################################################
# Initialization:

: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs

# Parameter defaults

OCF_RESKEY_raidconf_default=""
OCF_RESKEY_raiddev_default=""
OCF_RESKEY_homehost_default=""
OCF_RESKEY_force_stop_default="true"
OCF_RESKEY_udev_default="true"
OCF_RESKEY_force_clones_default="false"

: ${OCF_RESKEY_raidconf=${OCF_RESKEY_raidconf_default}}
: ${OCF_RESKEY_raiddev=${OCF_RESKEY_raiddev_default}}
: ${OCF_RESKEY_homehost=${OCF_RESKEY_homehost_default}}
: ${OCF_RESKEY_force_stop=${OCF_RESKEY_force_stop_default}}
: ${OCF_RESKEY_udev=${OCF_RESKEY_udev_default}}
: ${OCF_RESKEY_force_clones=${OCF_RESKEY_force_clones_default}}

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

usage() {
	cat <<-EOT
	usage: $0 {start|stop|status|monitor|validate-all|usage|meta-data}
	EOT
}

meta_data() {
	cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="Raid1" version="1.0">
<version>1.0</version>

<longdesc lang="en">
This resource agent manages Linux software RAID (MD) devices on
a shared storage medium. It uses mdadm(8) to start, stop, and
monitor the MD devices. Raidtools are supported, but deprecated.
See https://raid.wiki.kernel.org/index.php/Linux_Raid for more
information.
</longdesc>
<shortdesc lang="en">Manages Linux software RAID (MD) devices on shared storage</shortdesc>

<parameters>
<parameter name="raidconf" unique="0" required="1">
<longdesc lang="en">
The RAID configuration file, e.g. /etc/mdadm.conf.
</longdesc>
<shortdesc lang="en">RAID config file</shortdesc>
<content type="string" default="${OCF_RESKEY_raidconf_default}" />
</parameter>

<parameter name="raiddev" unique="0" required="1">
<longdesc lang="en">
One or more block devices to use, space separated. Alternatively,
set to "auto" to manage all devices specified in raidconf.
</longdesc>
<shortdesc lang="en">block device</shortdesc>
<content type="string" default="${OCF_RESKEY_raiddev_default}" />
</parameter>

<parameter name="homehost" unique="0" required="0">
<longdesc lang="en">
The value for the homehost directive; this is an mdadm feature to
protect RAIDs against being activated by accident. It is recommended to
create RAIDs managed by the cluster with "homehost" set to a special
value, so they are not accidentally auto-assembled by nodes not
supposed to own them.
</longdesc>
<shortdesc lang="en">Homehost for mdadm</shortdesc>
<content type="string" default="${OCF_RESKEY_homehost_default}" />
</parameter>

<parameter name="force_stop" unique="0" required="0">
<longdesc lang="en">
If processes or kernel threads are using the array, it cannot be
stopped. We will try to stop processes, first by sending TERM and
then, if that doesn't help in $PROC_CLEANUP_TIME seconds, using KILL.
The lsof(8) program is required to get the list of array users.
Of course, the kernel threads cannot be stopped this way.
If the processes are critical for data integrity, then set this
parameter to false. Note that in that case the stop operation
will fail and the node will be fenced.
</longdesc>
<shortdesc lang="en">force stop processes using the array</shortdesc>
<content type="boolean" default="${OCF_RESKEY_force_stop_default}" />
</parameter>

<parameter name="udev" unique="0" required="0">
<longdesc lang="en">
Wait until udevd creates a device in the start operation. On a
normally loaded host this should happen quickly, but you may be
unlucky. If you are not using udev set this to "no".
</longdesc>
<shortdesc lang="en">udev</shortdesc>
<content type="boolean" default="${OCF_RESKEY_udev_default}" />
</parameter>

<parameter name="force_clones">
<longdesc lang="en">
Activating the same md RAID array on multiple nodes at the same time
will result in data corruption and thus is forbidden by default.

A safe example could be an array that is only named identically across
all nodes, but is in fact distinct.

Only set this to "true" if you know what you are doing!
</longdesc>
<shortdesc lang="en">force ability to run as a clone</shortdesc>
<content type="boolean" default="${OCF_RESKEY_force_clones_default}" />
</parameter>

</parameters>

<actions>
<action name="start" timeout="20s" />
<action name="stop" timeout="20s" />
<action name="status" depth="0" timeout="20s" interval="10s" />
<action name="monitor" depth="0" timeout="20s" interval="10s" />
<action name="validate-all" timeout="5s" />
<action name="meta-data" timeout="5s" />
</actions>
</resource-agent>
END
}

udev_settle() {
	if ocf_is_true $WAIT_FOR_UDEV; then
		udevadm settle $*
	fi
}
list_conf_arrays() {
	test -f $RAIDCONF || {
		ocf_exit_reason "$RAIDCONF gone missing!"
		exit $OCF_ERR_GENERIC
	}
	grep ^ARRAY $RAIDCONF | awk '{print $2}'
}
forall() {
	local func=$1
	local checkall=$2
	local mddev rc=0
	for mddev in $RAIDDEVS; do
		$func $mddev
		rc=$(($rc | $?))
		[ "$checkall" = all ] && continue
		[ $rc -ne 0 ] && return $rc
	done
	return $rc
}
are_arrays_stopped() {
	local rc mddev
	for mddev in $RAIDDEVS; do
		raid1_monitor_one $mddev
		rc=$?
		[ $rc -ne $OCF_NOT_RUNNING ] && break
	done
	test $rc -eq $OCF_NOT_RUNNING
}

md_assemble() {
	local mddev=$1
	$MDADM --assemble $mddev --config=$RAIDCONF $MDADM_HOMEHOST
	udev_settle --exit-if-exists=$mddev
}
#
# START: Start up the RAID device
#
raid1_start() {
	local rc
	raid1_monitor
	rc=$?
	if [ $rc -eq $OCF_SUCCESS ]; then
		# md already online, nothing to do.
		return $OCF_SUCCESS
	fi
	if [ $rc -ne $OCF_NOT_RUNNING ]; then
		# If the array is in a broken state, this agent doesn't
		# know how to repair that.
		ocf_exit_reason "$RAIDDEVS in a broken state; cannot start (rc=$rc)"
		return $OCF_ERR_GENERIC
	fi

	if [ $HAVE_RAIDTOOLS = "true" ]; then
	    # Run raidstart to start up the RAID array
	    $RAIDSTART --configfile $RAIDCONF $MDDEV
	else
		forall md_assemble all
	fi

	raid1_monitor
	if [ $? -eq $OCF_SUCCESS ]; then
	    return $OCF_SUCCESS
	else
	    ocf_exit_reason "Couldn't start RAID for $RAIDDEVS"
	    return $OCF_ERR_GENERIC
	fi
}

#
# STOP: stop the RAID device
#
mark_readonly() {
	local mddev=$1
	local rc
	ocf_log info "Attempting to mark array $mddev readonly"
	$MDADM --readonly $mddev --config=$RAIDCONF
	rc=$?
	if [ $rc -ne 0 ]; then
		ocf_exit_reason "Failed to set $mddev readonly (rc=$rc)"
	fi
	return $rc
}
mknod_raid1_stop() {
	# first create a block device file, then try to stop the
	# array
	local rc n tmp_block_file
	n=`echo $1 | sed 's/[^0-9]*//'`
	if ! ocf_is_decimal "$n"; then
		ocf_log warn "could not get the minor device number from $1"
		return 1
	fi
	tmp_block_file="$HA_RSCTMP/${OCF_RESOURCE_INSTANCE}-`basename $1`"
	rm -f $tmp_block_file
	ocf_log info "block device file $1 missing, creating one in order to stop the array"
	mknod $tmp_block_file b 9 $n
	$MDADM --stop $tmp_block_file --config=$RAIDCONF
	rc=$?
	rm -f $tmp_block_file
	return $rc
}
raid1_stop_one() {
	ocf_log info "Stopping array $1"
	if [ -b "$1" ]; then
		$MDADM --stop $1 --config=$RAIDCONF &&
			return
	else
		# newer mdadm releases can stop arrays when given the
		# basename; try that first
		$MDADM --stop `basename $1` --config=$RAIDCONF &&
			return
		# otherwise create a block device file
		mknod_raid1_stop $1
	fi
}
get_users_pids() {
	local mddev=$1
	local outp l
	ocf_log debug "running lsof to list $mddev users..."
	outp=`lsof $mddev | tail -n +2`
	echo "$outp" | awk '{print $2}' | sort -u
	echo "$outp" | while read l; do
		ocf_log warn "$l"
	done
}
stop_raid_users() {
	local pids
	pids=`forall get_users_pids all | sort -u`
	if [ -z "$pids" ]; then
		ocf_log warn "lsof reported no users holding arrays"
		return 2
	else
		ocf_stop_processes TERM $PROC_CLEANUP_TIME $pids
	fi
}
stop_arrays() {
	if [ $HAVE_RAIDTOOLS = "true" ]; then
		$RAIDSTOP --configfile $RAIDCONF $MDDEV
	else
		forall raid1_stop_one all
	fi
}
showusers() {
	local disk
	for disk; do
		if have_binary lsof; then
			ocf_log info "running lsof to list $disk users..."
			ocf_run -warn lsof $disk
		fi
		if [ -d /sys/block/$disk/holders ]; then
			ocf_log info "ls -l /sys/block/$disk/holders"
			ocf_run -warn ls -l /sys/block/$disk/holders
		fi
	done
}
raid1_stop() {
	local rc
	# See if the MD device is already cleanly stopped:
	if are_arrays_stopped; then
		return $OCF_SUCCESS
	fi

	# Turn off raid
	if ! stop_arrays; then
		if ocf_is_true $FORCESTOP; then
			if have_binary lsof; then
				stop_raid_users
				case $? in
				2) false;;
				*) stop_arrays;;
				esac
			else
				ocf_log warn "install lsof(8) to list users holding the disk"
				false
			fi
		else
			false
		fi
	fi
	rc=$?

	if [ $rc -ne 0 ]; then
		ocf_log warn "Couldn't stop RAID for $RAIDDEVS (rc=$rc)"
 		showusers $RAIDDEVS
		if [ $HAVE_RAIDTOOLS != "true" ]; then
			forall mark_readonly all
		fi
		return $OCF_ERR_GENERIC
	fi

	if are_arrays_stopped; then
		return $OCF_SUCCESS
	fi

	ocf_exit_reason "RAID $RAIDDEVS still active after stop command!"
	return $OCF_ERR_GENERIC
}

#
# monitor: a less noisy status
#
raid1_monitor_one() {
	local mddev=$1
	local md=
	local rc
	local TRY_READD=0
	local pbsize
	# check if the md device exists first
	# but not if we are in the stop operation
	# device existence is important only for the running arrays
	if [ "$__OCF_ACTION" != "stop" ]; then
		if [ -h "$mddev" ]; then
			md=$(ls $mddev -l | awk -F'/' '{print $NF}')
		elif [ -b "$mddev" ]; then
			md=$(echo $mddev | sed 's,/dev/,,')
		else
			ocf_log info "$mddev is not a block device"
			return $OCF_NOT_RUNNING
		fi
	fi
	if ! grep -e "^$md[ \t:]" /proc/mdstat >/dev/null ; then
		ocf_log info "$md not found in /proc/mdstat"
		return $OCF_NOT_RUNNING
	fi
	if [ $HAVE_RAIDTOOLS != "true" ]; then
		$MDADM --detail --test $mddev >/dev/null 2>&1 ; rc=$?
		case $rc in
		0)	;;
		1)	ocf_log warn "$mddev has at least one failed device."
			TRY_READD=1
			;;
		2)	ocf_exit_reason "$mddev has failed."
			return $OCF_ERR_GENERIC
			;;
		4)
			if [ "$__OCF_ACTION" = "stop" ] ; then
				# There may be a transient invalid device after
				# we stop MD due to uevent processing, the
				# original device is stopped though.
				return $OCF_NOT_RUNNING
			else
				ocf_exit_reason "mdadm failed on $mddev."
				return $OCF_ERR_GENERIC
			fi
			;;
		*)	ocf_exit_reason "mdadm returned an unknown result ($rc)."
			return $OCF_ERR_GENERIC
			;;
		esac
	fi
	if [ "$__OCF_ACTION" = "monitor" -a "$OCF_RESKEY_CRM_meta_interval" != 0 \
		-a $TRY_READD -eq 1 -a $OCF_CHECK_LEVEL -gt 0 ]; then
		ocf_log info "Attempting recovery sequence to re-add devices on $mddev:"
		$MDADM $mddev --fail detached
		$MDADM $mddev --remove failed
		$MDADM $mddev --re-add missing
		# TODO: At this stage, there's nothing to actually do
		# here. Either this worked or it did not.
	fi

	pbsize=`(blockdev --getpbsz $mddev || stat -c "%o" $mddev) 2>/dev/null`
	if [ -z "$pbsize" ]; then
		ocf_log warn "both blockdev and stat could not get the block size (will use 4k)"
		pbsize=4096 # try with 4k
	fi
	if ! dd if=$mddev count=1 bs=$pbsize of=/dev/null \
	     iflag=direct >/dev/null 2>&1 ; then
		ocf_exit_reason "$mddev: I/O error on read"
		return $OCF_ERR_GENERIC
	fi

	return $OCF_SUCCESS
}

raid1_monitor() {
	forall raid1_monitor_one
}

#
# STATUS: is the raid device online or offline?
#
raid1_status() {
	# See if the MD device is online
	local rc
	raid1_monitor
	rc=$?
	if [ $rc -ne $OCF_SUCCESS ]; then
	    echo "stopped"
	else
	    echo "running"
	fi
	return $rc
}

raid1_validate_all() {
    return $OCF_SUCCESS
}

PROC_CLEANUP_TIME=3

if
  ( [ $# -ne 1 ] )
then
  usage
  exit $OCF_ERR_ARGS
fi

case "$1" in
  meta-data)
	meta_data
	exit $OCF_SUCCESS
	;;
  usage)
	usage
	exit $OCF_SUCCESS
	;;
  *)
	;;
esac

RAIDCONF="$OCF_RESKEY_raidconf"
MDDEV="$OCF_RESKEY_raiddev"
FORCESTOP="${OCF_RESKEY_force_stop}"
WAIT_FOR_UDEV="${OCF_RESKEY_udev}"

if [ -z "$RAIDCONF" ] ; then
	ocf_exit_reason "Please set OCF_RESKEY_raidconf!"
	exit $OCF_ERR_CONFIGURED
fi

if [ ! -r "$RAIDCONF" ] ; then
	ocf_exit_reason "Configuration file [$RAIDCONF] does not exist, or can not be opened!"
	exit $OCF_ERR_INSTALLED
fi

if [ -z "$MDDEV" ] ; then
	ocf_exit_reason "Please set OCF_RESKEY_raiddev to the Raid device you want to control!"
	exit $OCF_ERR_CONFIGURED
fi

if ocf_is_clone && ! ocf_is_true "$OCF_RESKEY_force_clones"; then
	ocf_exit_reason "md RAID arrays are NOT safe to run as a clone!"
	ocf_log err "Please read the comment on the force_clones parameter."
	exit $OCF_ERR_CONFIGURED
fi

if ocf_is_true $WAIT_FOR_UDEV && ! have_binary udevadm; then
	if [ "$__OCF_ACTION" = "start" ]; then
		ocf_log warn "either install udevadm or set udev to false"
		ocf_log info "setting udev to false!"
	fi
	WAIT_FOR_UDEV=0
fi

if ! ocf_is_true $WAIT_FOR_UDEV; then
	export MDADM_NO_UDEV=1
fi

if ocf_is_true $FORCESTOP && ! have_binary lsof; then
	ocf_log warn "Please install lsof(8), we may need it when stopping Raid device! Now continuing anyway ..."
fi

HAVE_RAIDTOOLS=false
if have_binary $MDADM >/dev/null 2>&1 ; then
  if [ -n "$OCF_RESKEY_homehost" ]; then
  	MDADM_HOMEHOST="--homehost=${OCF_RESKEY_homehost}"
  else
  	MDADM_HOMEHOST=""
  fi
else
  check_binary $RAIDSTART
  HAVE_RAIDTOOLS=true
fi

if [ $HAVE_RAIDTOOLS = true ]; then
	if [ "$MDDEV" = "auto" ]; then
		ocf_exit_reason "autoconf supported only with mdadm!"
		exit $OCF_ERR_INSTALLED
	elif [ `echo $MDDEV|wc -w` -gt 1 ]; then
		ocf_exit_reason "multiple devices supported only with mdadm!"
		exit $OCF_ERR_INSTALLED
	fi
fi

if [ "$MDDEV" = "auto" ]; then
	RAIDDEVS=`list_conf_arrays`
else
	RAIDDEVS="$MDDEV"
fi

# At this stage,
# [ $HAVE_RAIDTOOLS = false ] <=> we have $MDADM,
# otherwise we have raidtools (raidstart and raidstop)

# Look for how we are called
case "$1" in
  start)
	raid1_start
	;;
  stop)
	raid1_stop
	;;
  status)
	raid1_status
	;;
  monitor)
	raid1_monitor
	;;
  validate-all)
	raid1_validate_all
	;;
  *)
	usage
	exit $OCF_ERR_UNIMPLEMENTED
	;;
esac

exit $?