tcm_mod_builder.rst

  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>