#!/usr/bin/env bash

do_map() {
	# Read /etc/rbdtab to create non-existant mapping
	RET=0
	while read DEV PARAMS; do
		case "$DEV" in
		  ""|\#*)
			continue
			;;
		  */*)
			;;
		  *)
			DEV=rbd/$DEV
			;;
		esac
		logger -p "daemon.debug" -t rbdmap "Mapping '${DEV}'"
		newrbd=""
		MAP_RV=""
		OIFS=$IFS
		IFS=','
		CMDPARAMS=""
		for PARAM in ${PARAMS[@]}; do
			CMDPARAMS="$CMDPARAMS --$(echo $PARAM | tr '=' ' ')"
		done
		IFS=$OIFS
		if [ -b /dev/rbd/$DEV ]; then
			MAP_RV="$(readlink -f /dev/rbd/$DEV)"
		else
			MAP_RV="$(rbd device map $DEV $CMDPARAMS 2>&1)"
			if [ $? -eq 0 ]; then
			    newrbd="yes"
			else
			    RET=$((${RET}+$?))
			    logger -p "daemon.warning" -t rbdmap "Failed to map '${DEV}"
			    continue
			fi
		fi
		logger -p "daemon.debug" -t rbdmap "Mapped '${DEV}' to '${MAP_RV}'"

		if [ "$newrbd" ]; then
			## Mount new rbd
			MNT_RV=""
			mount --fake /dev/rbd/$DEV >>/dev/null 2>&1 \
			&& MNT_RV=$(mount -vn /dev/rbd/$DEV 2>&1)
			[ -n "${MNT_RV}" ] && logger -p "daemon.debug" -t rbdmap "Mounted '${MAP_RV}' to '${MNT_RV}'"

			## post-mapping
			if [ -x "/etc/ceph/rbd.d/${DEV}" ]; then
			    logger -p "daemon.debug" -t rbdmap "Running post-map hook '/etc/ceph/rbd.d/${DEV}'"
			    /etc/ceph/rbd.d/${DEV} map "/dev/rbd/${DEV}"
			fi
		fi
	done < $RBDMAPFILE
	exit ${RET}

}

unmount_unmap() {
	local rbd_dev=$1
	local mnts=$(findmnt --mtab --source ${rbd_dev} --noheadings \
							| awk '{print $1'})

	logger -p "daemon.debug" -t rbdmap "Unmapping '${rbd_dev}'"
	for mnt in ${mnts}; do
	    logger -p "daemon.debug" -t rbdmap "Unmounting '${mnt}'"
	    umount "${mnt}" >>/dev/null 2>&1
	    if mountpoint -q "${mnt}"; then
		  ## Un-mounting failed.
		  logger -p "daemon.warning" -t rbdmap "Failed to unmount '${mnt}'"
		  return 1
	    fi
	done
	## Un-mapping.
	rbd device unmap $rbd_dev >>/dev/null 2>&1
	if [ $? -ne 0 ]; then
	    logger -p "daemon.warning" -t rbdmap "Failed to unmap '${mnt}'"
	    return 1
	fi
	logger -p "daemon.debug" -t rbdmap "Unmapped '${rbd_dev}'"

	return 0
}

do_unmap_all() {
	RET=0
	## Unmount and unmap all rbd devices
	if ls /dev/rbd[0-9]* >/dev/null 2>&1; then
		for DEV in /dev/rbd[0-9]*; do
			## pre-unmapping
			for L in $(find /dev/rbd -type l); do
			    LL="${L##/dev/rbd/}"
			    if [ "$(readlink -f $L)" = "${DEV}" ] \
			    && [ -x "/etc/ceph/rbd.d/${LL}" ]; then
			        logger -p "daemon.debug" -t rbdmap "Running pre-unmap hook for '${DEV}': '/etc/ceph/rbd.d/${LL}'"
			        /etc/ceph/rbd.d/${LL} unmap "$L"
			        break
			    fi
			done

			unmount_unmap "$DEV" || RET=$((${RET}+$?))

		done
	fi
	exit ${RET}
}

do_unmap() {
	RET=0
	## skip if nothing is mapped
	ls /dev/rbd[0-9]* >/dev/null 2>&1 || exit ${RET}

	# Read /etc/rbdtab to create non-existant mapping
	while read DEV PARAMS; do
		case "$DEV" in
		  ""|\#*)
			continue
			;;
		  */*)
			;;
		  *)
			DEV=rbd/$DEV
			;;
		esac

		MAP_RV="$(readlink -f /dev/rbd/$DEV)"
		if [ ! -b $MAP_RV ]; then
			logger -p "daemon.debug" -t rbdmap "$DEV not mapped, skipping unmap"
			continue
		fi

		## pre-unmapping
		if [ -x "/etc/ceph/rbd.d/${DEV}" ]; then
			logger -p "daemon.debug" -t rbdmap "Running pre-unmap hook '/etc/ceph/rbd.d/${DEV}'"
			/etc/ceph/rbd.d/${DEV} unmap "/dev/rbd/${DEV}"
		fi

		unmount_unmap "$MAP_RV" || RET=$((${RET}+$?))

	done < $RBDMAPFILE
	exit ${RET}
}

# default to reasonable value if RBDMAPFILE not set in environment
RBDMAPFILE="${RBDMAPFILE:-/etc/ceph/rbdmap}"

if [ ! -f "$RBDMAPFILE" ]; then
	logger -p "daemon.warning" -t rbdmap "No $RBDMAPFILE found."
	exit 0
fi

case "$1" in
  map)
	do_map
	;;

  unmap)
	do_unmap
	;;

  unmap-all)
	do_unmap_all
	;;

  *)
	echo "Usage: rbdmap map | unmap | unmap-all"
esac
