TCM v4 结构模块脚本生成器¶
大家好，
本文档旨在作为一份简短的指南，介绍如何使用 tcm_mod_builder.py 脚本生成全新的功能性 TCM v4 结构 .ko 模块，一旦构建完成，只需使用以下命令即可立即加载，开始访问新的 TCM/ConfigFS 结构骨架：
modprobe $TCM_NEW_MOD
mkdir -p /sys/kernel/config/target/$TCM_NEW_MOD
该脚本将创建一个新的 drivers/target/$TCM_NEW_MOD/，并执行以下操作：
为 drivers/target/target_core_fabric_configs.c 逻辑生成新的 API 调用者：->make_tpg()、->drop_tpg()、->make_wwn()、->drop_wwn()。这些调用者会在 $TCM_NEW_MOD/$TCM_NEW_MOD_configfs.c 中创建。
为加载/卸载 LKM 和 TCM/ConfigFS 结构模块生成基本的基础设施，使用一个骨架 struct target_core_fabric_ops API 模板。
基于用户为正在构建的新结构模块定义的 T10 Proto_Ident，SPC-3 持久预留的 TransportID / Initiator 和 Target WWPN 相关处理程序会在 $TCM_NEW_MOD/$TCM_NEW_MOD_fabric.c 中自动生成，使用 drivers/target/target_core_fabric_lib.c 逻辑。
在 $TCM_NEW_MOD/$TCM_NEW_MOD_fabric.c 中，为所有其他数据 I/O 路径和结构相关的属性逻辑生成 NOP API 调用。
tcm_mod_builder.py 依赖于强制性的 '-p $PROTO_IDENT' 和 '-m $FABRIC_MOD_name' 参数，实际运行脚本如下所示：
target:/mnt/sdb/lio-core-2.6.git/Documentation/target# python tcm_mod_builder.py -p iSCSI -m tcm_nab5000
tcm_dir: /mnt/sdb/lio-core-2.6.git/Documentation/target/../../
Set fabric_mod_name: tcm_nab5000
Set fabric_mod_dir:
/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000
Using proto_ident: iSCSI
Creating fabric_mod_dir:
/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000
Writing file:
/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_base.h
Using tcm_mod_scan_fabric_ops:
/mnt/sdb/lio-core-2.6.git/Documentation/target/../../include/target/target_core_fabric_ops.h
Writing file:
/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_fabric.c
Writing file:
/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_fabric.h
Writing file:
/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/tcm_nab5000_configfs.c
Writing file:
/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/Kbuild
Writing file:
/mnt/sdb/lio-core-2.6.git/Documentation/target/../../drivers/target/tcm_nab5000/Kconfig
Would you like to add tcm_nab5000to drivers/target/Kbuild..? [yes,no]: yes
Would you like to add tcm_nab5000to drivers/target/Kconfig..? [yes,no]: yes
在 tcm_mod_builder.py 的末尾，脚本会要求将以下行添加到 drivers/target/Kbuild 中：
obj-$(CONFIG_TCM_NAB5000) += tcm_nab5000/
以及对 drivers/target/Kconfig 执行相同的操作：
source "drivers/target/tcm_nab5000/Kconfig"
运行 “make menuconfig” 并选择新的 CONFIG_TCM_NAB5000 项
<M> TCM_NAB5000 fabric module
使用 “make modules” 构建，完成后，你将得到：
target:/mnt/sdb/lio-core-2.6.git# ls -la drivers/target/tcm_nab5000/ total 1348 drwxr-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
加载新模块，创建一个 lun_0 configfs 组，并将新的 TCM Core IBLOCK 后端存储符号链接添加到端口
target:/mnt/sdb/lio-core-2.6.git# insmod drivers/target/tcm_nab5000.ko target:/mnt/sdb/lio-core-2.6.git# mkdir -p /sys/kernel/config/target/nab5000/iqn.foo/tpgt_1/lun/lun_0 target:/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_port target:/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 `-- version target:/mnt/sdb/lio-core-2.6.git# lsmod Module Size Used by tcm_nab5000 3935 4 iscsi_target_mod 193211 0 target_core_stgt 8090 0 target_core_pscsi 11122 1 target_core_file 9172 2 target_core_iblock 9280 1 target_core_mod 228575 31 tcm_nab5000,iscsi_target_mod,target_core_stgt,target_core_pscsi,target_core_file,target_core_iblock libfc 73681 0 scsi_debug 56265 0 scsi_tgt 8666 1 target_core_stgt configfs 20644 2 target_core_mod
未来的 TODO 项¶
添加更多 T10 proto_idents
让 tcm_mod_dump_fabric_ops() 更智能，并直接从 include/target/target_core_fabric_ops.h:struct target_core_fabric_ops 结构成员生成函数指针定义。
2010 年 10 月 5 日
Nicholas A. Bellinger <nab@linux-iscsi.org>