linux/Documentation/target/tcm_mod_builder.rst
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   1=========================================
   2The TCM v4 fabric module script generator
   3=========================================
   4
   5Greetings all,
   6
   7This document is intended to be a mini-HOWTO for using the tcm_mod_builder.py
   8script to generate a brand new functional TCM v4 fabric .ko module of your very own,
   9that once built can be immediately be loaded to start access the new TCM/ConfigFS
  10fabric skeleton, by simply using::
  11
  12        modprobe $TCM_NEW_MOD
  13        mkdir -p /sys/kernel/config/target/$TCM_NEW_MOD
  14
  15This script will create a new drivers/target/$TCM_NEW_MOD/, and will do the following
  16
  17        1) Generate new API callers for drivers/target/target_core_fabric_configs.c logic
  18           ->make_tpg(), ->drop_tpg(), ->make_wwn(), ->drop_wwn().  These are created
  19           into $TCM_NEW_MOD/$TCM_NEW_MOD_configfs.c
  20        2) Generate basic infrastructure for loading/unloading LKMs and TCM/ConfigFS fabric module
  21           using a skeleton struct target_core_fabric_ops API template.
  22        3) Based on user defined T10 Proto_Ident for the new fabric module being built,
  23           the TransportID / Initiator and Target WWPN related handlers for
  24           SPC-3 persistent reservation are automatically generated in $TCM_NEW_MOD/$TCM_NEW_MOD_fabric.c
  25           using drivers/target/target_core_fabric_lib.c logic.
  26        4) NOP API calls for all other Data I/O path and fabric dependent attribute logic
  27           in $TCM_NEW_MOD/$TCM_NEW_MOD_fabric.c
  28
  29tcm_mod_builder.py depends upon the mandatory '-p $PROTO_IDENT' and '-m
  30$FABRIC_MOD_name' parameters, and actually running the script looks like::
  31
  32  target:/mnt/sdb/lio-core-2.6.git/Documentation/target# python tcm_mod_builder.py -p iSCSI -m tcm_nab5000
  33  tcm_dir: /mnt/sdb/lio-core-2.6.git/Documentation/target/../../
  34  Set fabric_mod_name: tcm_nab5000
  35  Set fabric_mod_dir:
  36  /mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000
  37  Using proto_ident: iSCSI
  38  Creating fabric_mod_dir:
  39  /mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000
  40  Writing file:
  41  /mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_base.h
  42  Using tcm_mod_scan_fabric_ops:
  43  /mnt/sdb/lio-core-2.6.git/Documentation/target/../../include/target/target_core_fabric_ops.h
  44  Writing file:
  45  /mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_fabric.c
  46  Writing file:
  47  /mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_fabric.h
  48  Writing file:
  49  /mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_configfs.c
  50  Writing file:
  51  /mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/Kbuild
  52  Writing file:
  53  /mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/Kconfig
  54  Would you like to add tcm_nab5000to drivers/target/Kbuild..? [yes,no]: yes
  55  Would you like to add tcm_nab5000to drivers/target/Kconfig..? [yes,no]: yes
  56
  57At the end of tcm_mod_builder.py. the script will ask to add the following
  58line to drivers/target/Kbuild::
  59
  60        obj-$(CONFIG_TCM_NAB5000)       += tcm_nab5000/
  61
  62and the same for drivers/target/Kconfig::
  63
  64        source "drivers/target/tcm_nab5000/Kconfig"
  65
  66#) Run 'make menuconfig' and select the new CONFIG_TCM_NAB5000 item::
  67
  68        <M>   TCM_NAB5000 fabric module
  69
  70#) Build using 'make modules', once completed you will have::
  71
  72    target:/mnt/sdb/lio-core-2.6.git# ls -la drivers/target/tcm_nab5000/
  73    total 1348
  74    drwxr-xr-x 2 root root   4096 2010-10-05 03:23 .
  75    drwxr-xr-x 9 root root   4096 2010-10-05 03:22 ..
  76    -rw-r--r-- 1 root root    282 2010-10-05 03:22 Kbuild
  77    -rw-r--r-- 1 root root    171 2010-10-05 03:22 Kconfig
  78    -rw-r--r-- 1 root root     49 2010-10-05 03:23 modules.order
  79    -rw-r--r-- 1 root root    738 2010-10-05 03:22 tcm_nab5000_base.h
  80    -rw-r--r-- 1 root root   9096 2010-10-05 03:22 tcm_nab5000_configfs.c
  81    -rw-r--r-- 1 root root 191200 2010-10-05 03:23 tcm_nab5000_configfs.o
  82    -rw-r--r-- 1 root root  40504 2010-10-05 03:23 .tcm_nab5000_configfs.o.cmd
  83    -rw-r--r-- 1 root root   5414 2010-10-05 03:22 tcm_nab5000_fabric.c
  84    -rw-r--r-- 1 root root   2016 2010-10-05 03:22 tcm_nab5000_fabric.h
  85    -rw-r--r-- 1 root root 190932 2010-10-05 03:23 tcm_nab5000_fabric.o
  86    -rw-r--r-- 1 root root  40713 2010-10-05 03:23 .tcm_nab5000_fabric.o.cmd
  87    -rw-r--r-- 1 root root 401861 2010-10-05 03:23 tcm_nab5000.ko
  88    -rw-r--r-- 1 root root    265 2010-10-05 03:23 .tcm_nab5000.ko.cmd
  89    -rw-r--r-- 1 root root    459 2010-10-05 03:23 tcm_nab5000.mod.c
  90    -rw-r--r-- 1 root root  23896 2010-10-05 03:23 tcm_nab5000.mod.o
  91    -rw-r--r-- 1 root root  22655 2010-10-05 03:23 .tcm_nab5000.mod.o.cmd
  92    -rw-r--r-- 1 root root 379022 2010-10-05 03:23 tcm_nab5000.o
  93    -rw-r--r-- 1 root root    211 2010-10-05 03:23 .tcm_nab5000.o.cmd
  94
  95#) Load the new module, create a lun_0 configfs group, and add new TCM Core
  96   IBLOCK backstore symlink to port::
  97
  98    target:/mnt/sdb/lio-core-2.6.git# insmod drivers/target/tcm_nab5000.ko
  99    target:/mnt/sdb/lio-core-2.6.git# mkdir -p /sys/kernel/config/target/nab5000/iqn.foo/tpgt_1/lun/lun_0
 100    target:/mnt/sdb/lio-core-2.6.git# cd /sys/kernel/config/target/nab5000/iqn.foo/tpgt_1/lun/lun_0/
 101    target:/sys/kernel/config/target/nab5000/iqn.foo/tpgt_1/lun/lun_0# ln -s /sys/kernel/config/target/core/iblock_0/lvm_test0 nab5000_port
 102
 103    target:/sys/kernel/config/target/nab5000/iqn.foo/tpgt_1/lun/lun_0# cd -
 104    target:/mnt/sdb/lio-core-2.6.git# tree /sys/kernel/config/target/nab5000/
 105    /sys/kernel/config/target/nab5000/
 106    |-- discovery_auth
 107    |-- iqn.foo
 108    |   `-- tpgt_1
 109    |       |-- acls
 110    |       |-- attrib
 111    |       |-- lun
 112    |       |   `-- lun_0
 113    |       |       |-- alua_tg_pt_gp
 114    |       |       |-- alua_tg_pt_offline
 115    |       |       |-- alua_tg_pt_status
 116    |       |       |-- alua_tg_pt_write_md
 117    |   |       `-- nab5000_port -> ../../../../../../target/core/iblock_0/lvm_test0
 118    |       |-- np
 119    |       `-- param
 120    `-- version
 121
 122    target:/mnt/sdb/lio-core-2.6.git# lsmod
 123    Module                  Size  Used by
 124    tcm_nab5000             3935  4
 125    iscsi_target_mod      193211  0
 126    target_core_stgt        8090  0
 127    target_core_pscsi      11122  1
 128    target_core_file        9172  2
 129    target_core_iblock      9280  1
 130    target_core_mod       228575  31
 131    tcm_nab5000,iscsi_target_mod,target_core_stgt,target_core_pscsi,target_core_file,target_core_iblock
 132    libfc                  73681  0
 133    scsi_debug             56265  0
 134    scsi_tgt                8666  1 target_core_stgt
 135    configfs               20644  2 target_core_mod
 136
 137----------------------------------------------------------------------
 138
 139Future TODO items
 140=================
 141
 142        1) Add more T10 proto_idents
 143        2) Make tcm_mod_dump_fabric_ops() smarter and generate function pointer
 144           defs directly from include/target/target_core_fabric_ops.h:struct target_core_fabric_ops
 145           structure members.
 146
 147October 5th, 2010
 148
 149Nicholas A. Bellinger <nab@linux-iscsi.org>
 150