#!/bin/bash

IQN=$1

if [[ -z "${IQN}" ]]; then
	echo "usage: $0 TargetIQN"
        echo ""

	exit
fi

MULTIPATH=0
IQNTESTLIST=$(grep -h ${IQN} /sys/class/iscsi_session/*/targetname)
for IQNTEST in ${IQNTESTLIST}; do
	if [ "${IQNTEST}" != "${IQN}" ]; then
		echo "IQN not found"
		echo ""

		exit
	fi

	MULTIPATH=$((MULTIPATH + 1))
done

SESSIONFOLDERLIST=$(grep -l ${IQN} /sys/class/iscsi_session/*/targetname | xargs realpath)

declare -A ADDRESSES
declare -A BLOCKDEVICES
for SESSIONFOLDER in ${SESSIONFOLDERLIST}; do
	SESSION=$(echo "${SESSIONFOLDER}" | sed 's/.*session\([0-9]*\).*/\1/g')
	HOST=$(echo "${SESSIONFOLDER}" | sed 's/.*host\([0-9]*\).*/\1/g')

	SCSIADDRESS=$(echo "${SESSIONFOLDER}" | sed 's/\(.*\)\/iscsi_session.*/\1/g' | xargs ls -1 | grep "target${HOST}" | sed 's/target//g')
	MAJOR=$(echo "${SCSIADDRESS}" | cut -d ":" -f 2)
	MINOR=$(echo "${SCSIADDRESS}" | cut -d ":" -f 3)

	FULLSCSIADDRESS=$(echo "${SESSIONFOLDER}" | sed "s/\(.*\)\/iscsi_session.*/\1\/target${SCSIADDRESS}/g" | xargs ls -1 | grep ":")
	LUN=$(echo "${FULLSCSIADDRESS}" | cut -d ":" -f 4)

	ADDRESS="[${SESSION}]:scsi$HOST:${MAJOR}:${MINOR}:${LUN}"
	ADDRESSES+="${ADDRESS} "

	BLOCKDEVICE=$(echo "${SESSIONFOLDER}" | sed "s/\(.*\)\/iscsi_session.*/\1\/target${SCSIADDRESS}\/${FULLSCSIADDRESS}\/block/g" | xargs ls -1 | xargs printf "/dev/%s")
	BLOCKDEVICES+="${BLOCKDEVICE} "
done

MULTIPATHDEVICE=$(multipath -l ${BLOCKDEVICES[0]} | grep 'mpath' | sed -e 's/^\([a-z]*\) .*/\1/g')
if [ ! -z "${MULTIPATHDEVICE}" ]; then
	BLOCKDEVICE="/dev/mapper/${MULTIPATHDEVICE}"
fi

MOUNTPOINT=$(grep "${BLOCKDEVICE}" /proc/mounts | head -n 1 | cut -d " " -f 2)

if [[ -z "${MOUNTPOINT}" || ! -d "${MOUNTPOINT}" ]]; then
	echo "IQN ${IQN} is not mounted"
        echo ""

	exit
fi

fstrim -v ${MOUNTPOINT}