block-iscsi

#!/bin/bash -x
# block-iscsi  -  2009 Keith Herron <keith@backdrift.org>
#
# multipath enabled block-iscsi xen block script.
#
# Note: This script depends on a block-iscsi.conf file
#       located in the same directory.  This file contains
#       an array of available iSCSI target IPs
#

dir=$(dirname "$0")
. "$dir/block-common.sh"
. "$dir/block-iscsi.conf"

# Log which mode we are in
logger -t block-iscsi "*** Beginning device $command ***"

# Fetch the iqn we specify in the domu config file
#
IQN=$(xenstore_read "$XENBUS_PATH/params")

logger -t block-iscsi "cmd:xenstore_read "$XENBUS_PATH/params""

logger -t block-iscsi "IQN: ${IQN}"

# We define portal ip in order to support new luns which don't yet have
# /var/lib/iscsi/node entrys yet, not dynamic but avoids manual discovery
#


for PORTAL in ${PORTALS[@]}; do
  logger -t block-iscsi `iscsiadm -m discovery -t st -p $PORTAL`
done

logger -t block-iscsi "iscsiadm -m discovery -t st -p $PORTAL"

# Using the iscsi node directory we can determine the ip and port of
# our iscsi target on a lun by lun basis

#  Codigo original, en debian la ruta de los nodos se crea en /etc/iscsi/nodes
#  IP=`ls /var/lib/iscsi/nodes/${IQN} | cut -d , -f 1`
#  PORT=`ls /var/lib/iscsi/nodes/${IQN} | cut -d , -f 2`

IP=`ls /etc/iscsi/nodes/${IQN} | cut -d , -f 1`
PORT=`ls /etc/iscsi/nodes/${IQN} | cut -d , -f 2`

logger -t block-iscsi "TARGET: ${IP}:${PORT}"

# This is called by each command to determine which multipath map to use
#
function get_mpath_map {

   logger -t block-iscsi "Funcion multipath. Obtenemos el scsi device..."

   # Re-run multipath to ensure that maps are up to date
   #
   #multipath
   #sleep 2

   # Now we determine which /dev/sd* device belongs to the iqn
   #
   logger -t block-iscsi "/bin/readlink /dev/disk/by-path/ip-${IP}:${PORT}-iscsi-${IQN}-lun-0"
   logger -t block-iscsi "/dev/`/usr/bin/basename \`/bin/readlink /dev/disk/by-path/ip-${IP}:${PORT}-iscsi-${IQN}-lun-0\``"
   SCSI_DEV="/dev/`basename \`/bin/readlink /dev/disk/by-path/ip-${IP}:${PORT}-iscsi-${IQN}-lun-0\``"
   logger -t block-iscsi "scsi device: ${SCSI_DEV}"

   # And using the /dev/sd* device we can determine its corresponding multipath entry

   #MPATH_MAP="/dev/mapper/`multipath -ll ${SCSI_DEV} | head -1 | awk '{ print $1}'`"
   #logger -t block-iscsi "mpath device: ${MPATH_MAP}"
   MPATH_MAP=${SCSI_DEV}
}

case $command in
   add)
      # Login to the target
      logger -t block-iscsi "logging in to ${IQN} on ${IP}:${PORT}"
      sleep 5
      #FIXME needs more advanced race condition logic
      iscsiadm -m node -T ${IQN} -p ${IP}:${PORT} --login | logger -t block-iscsi
      sleep 5
      #FIXME needs more advanced race condition logic
      get_mpath_map

      if [ -a ${MPATH_MAP} ]; then
         logger -t block-iscsi "${command}ing device: ${MPATH_MAP}"
         write_dev ${MPATH_MAP}
      fi
   ;;

   remove)
      get_mpath_map
      logger -t block-iscsi "MPATH_MAP: ${MPATH_MAP}"

      if [ -a ${MPATH_MAP} ]; then
         logger -t block-iscsi "flushing buffers on ${MPATH_MAP}"
         blockdev --flushbufs ${MPATH_MAP}
         logger -t block-iscsi "attempting logout of ${IQN} on ${IP}:${PORT}"
         iscsiadm -m node -T ${IQN} -p ${IP}:${PORT} --logout | logger -t block-iscsi
         sleep  10
         #FIXME needs more advanced race condition logic
      fi
      sleep 5
      #FIXME needs more advanced race condition logic
   ;;
esac