The TCM v4 fabric module script generator¶

Greetings all,

This document is intended to be a mini-HOWTO for using the tcm_mod_builder.pyscript to generate a brand new functional TCM v4 fabric .ko module of your very own,that once built can be immediately be loaded to start access the new TCM/ConfigFSfabric skeleton, by simply using:

modprobe $TCM_NEW_MODmkdir -p /sys/kernel/config/target/$TCM_NEW_MOD

This script will create a new drivers/target/$TCM_NEW_MOD/, and will do the following

1. Generate new API callers for drivers/target/target_core_fabric_configs.c logic->make_tpg(), ->drop_tpg(), ->make_wwn(), ->drop_wwn(). These are createdinto $TCM_NEW_MOD/$TCM_NEW_MOD_configfs.c

2. Generate basic infrastructure for loading/unloading LKMs and TCM/ConfigFS fabric moduleusing a skeletonstructtarget_core_fabric_ops API template.

3. Based on user defined T10 Proto_Ident for the new fabric module being built,the TransportID / Initiator and Target WWPN related handlers forSPC-3 persistent reservation are automatically generated in $TCM_NEW_MOD/$TCM_NEW_MOD_fabric.cusing drivers/target/target_core_fabric_lib.c logic.

4. NOP API calls for all other Data I/O path and fabric dependent attribute logicin $TCM_NEW_MOD/$TCM_NEW_MOD_fabric.c

tcm_mod_builder.py depends upon the mandatory ‘-p $PROTO_IDENT’ and ‘-m$FABRIC_MOD_name’ parameters, and actually running the script looks like:

target:/mnt/sdb/lio-core-2.6.git/Documentation/target# python tcm_mod_builder.py -p iSCSI -m tcm_nab5000tcm_dir: /mnt/sdb/lio-core-2.6.git/Documentation/target/../../Set fabric_mod_name: tcm_nab5000Set fabric_mod_dir:/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000Using proto_ident: iSCSICreating fabric_mod_dir:/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000Writing file:/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_base.hUsing tcm_mod_scan_fabric_ops:/mnt/sdb/lio-core-2.6.git/Documentation/target/../../include/target/target_core_fabric_ops.hWriting file:/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_fabric.cWriting file:/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_fabric.hWriting file:/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_configfs.cWriting file:/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/KbuildWriting file:/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/KconfigWould you like to add tcm_nab5000to drivers/target/Kbuild..? [yes,no]: yesWould you like to add tcm_nab5000to drivers/target/Kconfig..? [yes,no]: yes

At the end of tcm_mod_builder.py. the script will ask to add the followingline to drivers/target/Kbuild:

obj-$(CONFIG_TCM_NAB5000)       += tcm_nab5000/

and the same for drivers/target/Kconfig:

source "drivers/target/tcm_nab5000/Kconfig"

1. Run ‘make menuconfig’ and select the new CONFIG_TCM_NAB5000 item:

   <M>   TCM_NAB5000 fabric module

2. Build using ‘make modules’, once completed you will have:

   target:/mnt/sdb/lio-core-2.6.git# ls -la drivers/target/tcm_nab5000/total 1348drwxr-xr-x 2 root root   4096 2010-10-05 03:23 .drwxr-xr-x 9 root root   4096 2010-10-05 03:22 ..-rw-r--r-- 1 root root    282 2010-10-05 03:22 Kbuild-rw-r--r-- 1 root root    171 2010-10-05 03:22 Kconfig-rw-r--r-- 1 root root     49 2010-10-05 03:23 modules.order-rw-r--r-- 1 root root    738 2010-10-05 03:22 tcm_nab5000_base.h-rw-r--r-- 1 root root   9096 2010-10-05 03:22 tcm_nab5000_configfs.c-rw-r--r-- 1 root root 191200 2010-10-05 03:23 tcm_nab5000_configfs.o-rw-r--r-- 1 root root  40504 2010-10-05 03:23 .tcm_nab5000_configfs.o.cmd-rw-r--r-- 1 root root   5414 2010-10-05 03:22 tcm_nab5000_fabric.c-rw-r--r-- 1 root root   2016 2010-10-05 03:22 tcm_nab5000_fabric.h-rw-r--r-- 1 root root 190932 2010-10-05 03:23 tcm_nab5000_fabric.o-rw-r--r-- 1 root root  40713 2010-10-05 03:23 .tcm_nab5000_fabric.o.cmd-rw-r--r-- 1 root root 401861 2010-10-05 03:23 tcm_nab5000.ko-rw-r--r-- 1 root root    265 2010-10-05 03:23 .tcm_nab5000.ko.cmd-rw-r--r-- 1 root root    459 2010-10-05 03:23 tcm_nab5000.mod.c-rw-r--r-- 1 root root  23896 2010-10-05 03:23 tcm_nab5000.mod.o-rw-r--r-- 1 root root  22655 2010-10-05 03:23 .tcm_nab5000.mod.o.cmd-rw-r--r-- 1 root root 379022 2010-10-05 03:23 tcm_nab5000.o-rw-r--r-- 1 root root    211 2010-10-05 03:23 .tcm_nab5000.o.cmd

3. Load the new module, create a lun_0 configfs group, and add new TCM CoreIBLOCK backstore symlink to port:

   target:/mnt/sdb/lio-core-2.6.git# insmod drivers/target/tcm_nab5000.kotarget:/mnt/sdb/lio-core-2.6.git# mkdir -p /sys/kernel/config/target/nab5000/iqn.foo/tpgt_1/lun/lun_0target:/mnt/sdb/lio-core-2.6.git# cd /sys/kernel/config/target/nab5000/iqn.foo/tpgt_1/lun/lun_0/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_porttarget:/sys/kernel/config/target/nab5000/iqn.foo/tpgt_1/lun/lun_0# cd -target:/mnt/sdb/lio-core-2.6.git# tree /sys/kernel/config/target/nab5000//sys/kernel/config/target/nab5000/|-- discovery_auth|-- iqn.foo|   `-- tpgt_1|       |-- acls|       |-- attrib|       |-- lun|       |   `-- lun_0|       |       |-- alua_tg_pt_gp|       |       |-- alua_tg_pt_offline|       |       |-- alua_tg_pt_status|       |       |-- alua_tg_pt_write_md|   |       `-- nab5000_port -> ../../../../../../target/core/iblock_0/lvm_test0|       |-- np|       `-- param`-- versiontarget:/mnt/sdb/lio-core-2.6.git# lsmodModule                  Size  Used bytcm_nab5000             3935  4iscsi_target_mod      193211  0target_core_stgt        8090  0target_core_pscsi      11122  1target_core_file        9172  2target_core_iblock      9280  1target_core_mod       228575  31tcm_nab5000,iscsi_target_mod,target_core_stgt,target_core_pscsi,target_core_file,target_core_iblocklibfc                  73681  0scsi_debug             56265  0scsi_tgt                8666  1 target_core_stgtconfigfs               20644  2 target_core_mod