Documentation/target/target-export-device

   1 #!/bin/sh
   2 #
   3 # This script illustrates the sequence of operations in configfs to
   4 # create a very simple LIO iSCSI target with a file or block device
   5 # backstore.
   6 #
   7 # (C) Copyright 2014 Christophe Vu-Brugier <cvubrugier@fastmail.fm>
   8 #
   9
  10 print_usage() {
  11     cat <<EOF
  12 Usage: $(basename $0) [-p PORTAL] DEVICE|FILE
  13 Export a block device or a file as an iSCSI target with a single LUN
  14 EOF
  15 }
  16
  17 die() {
  18     echo $1
  19     exit 1
  20 }
  21
  22 while getopts "hp:" arg; do
  23     case $arg in
  24         h) print_usage; exit 0;;
  25         p) PORTAL=${OPTARG};;
  26     esac
  27 done
  28 shift $(($OPTIND - 1))
  29
  30 DEVICE=$1
  31 [ -n "$DEVICE" ] || die "Missing device or file argument"
  32 [ -b $DEVICE -o -f $DEVICE ] || die "Invalid device or file: ${DEVICE}"
  33 IQN="iqn.2003-01.org.linux-iscsi.$(hostname):$(basename $DEVICE)"
  34 [ -n "$PORTAL" ] || PORTAL="0.0.0.0:3260"
  35
  36 CONFIGFS=/sys/kernel/config
  37 CORE_DIR=$CONFIGFS/target/core
  38 ISCSI_DIR=$CONFIGFS/target/iscsi
  39
  40 # Load the target modules and mount the config file system
  41 lsmod | grep -q configfs || modprobe configfs
  42 lsmod | grep -q target_core_mod || modprobe target_core_mod
  43 mount | grep -q ^configfs || mount -t configfs none $CONFIGFS
  44 mkdir -p $ISCSI_DIR
  45
  46 # Create a backstore
  47 if [ -b $DEVICE ]; then
  48     BACKSTORE_DIR=$CORE_DIR/iblock_0/data
  49     mkdir -p $BACKSTORE_DIR
  50     echo "udev_path=${DEVICE}" > $BACKSTORE_DIR/control
  51 else
  52     BACKSTORE_DIR=$CORE_DIR/fileio_0/data
  53     mkdir -p $BACKSTORE_DIR
  54     DEVICE_SIZE=$(du -b $DEVICE | cut -f1)
  55     echo "fd_dev_name=${DEVICE}" > $BACKSTORE_DIR/control
  56     echo "fd_dev_size=${DEVICE_SIZE}" > $BACKSTORE_DIR/control
  57     echo 1 > $BACKSTORE_DIR/attrib/emulate_write_cache
  58 fi
  59 echo 1 > $BACKSTORE_DIR/enable
  60
  61 # Create an iSCSI target and a target portal group (TPG)
  62 mkdir $ISCSI_DIR/$IQN
  63 mkdir $ISCSI_DIR/$IQN/tpgt_1/
  64
  65 # Create a LUN
  66 mkdir $ISCSI_DIR/$IQN/tpgt_1/lun/lun_0
  67 ln -s $BACKSTORE_DIR $ISCSI_DIR/$IQN/tpgt_1/lun/lun_0/data
  68 echo 1 > $ISCSI_DIR/$IQN/tpgt_1/enable
  69
  70 # Create a network portal
  71 mkdir $ISCSI_DIR/$IQN/tpgt_1/np/$PORTAL
  72
  73 # Disable authentication
  74 echo 0 > $ISCSI_DIR/$IQN/tpgt_1/attrib/authentication
  75 echo 1 > $ISCSI_DIR/$IQN/tpgt_1/attrib/generate_node_acls
  76
  77 # Allow write access for non authenticated initiators
  78 echo 0 > $ISCSI_DIR/$IQN/tpgt_1/attrib/demo_mode_write_protect
  79
  80 echo "Target ${IQN}, portal ${PORTAL} has been created"