[SCSI] target: Add LIO target core v4.0.0-rc6

LIO target is a full featured in-kernel target framework with the
following feature set:

High-performance, non-blocking, multithreaded architecture with SIMD
support.

Advanced SCSI feature set:

    * Persistent Reservations (PRs)
    * Asymmetric Logical Unit Assignment (ALUA)
    * Protocol and intra-nexus multiplexing, load-balancing and failover (MC/S)
    * Full Error Recovery (ERL=0,1,2)
    * Active/active task migration and session continuation (ERL=2)
    * Thin LUN provisioning (UNMAP and WRITE_SAMExx)

Multiprotocol target plugins

Storage media independence:

    * Virtualization of all storage media; transparent mapping of IO to LUNs
    * No hard limits on number of LUNs per Target; maximum LUN size ~750 TB
    * Backstores: SATA, SAS, SCSI, BluRay, DVD, FLASH, USB, ramdisk, etc.

Standards compliance:

    * Full compliance with IETF (RFC 3720)
    * Full implementation of SPC-4 PRs and ALUA

Significant code cleanups done by Christoph Hellwig.

[jejb: fix up for new block bdev exclusive interface. Minor fixes from
 Randy Dunlap and Dan Carpenter.]
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

Documentation/target/tcm_mod_builder.txt

@@ -0,0 +1,145 @@
+>>>>>>>>>> The TCM v4 fabric module script generator <<<<<<<<<<
+
+Greetings all,
+
+This document is intended to be a mini-HOWTO for using the tcm_mod_builder.py
+script 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/ConfigFS
+fabric skeleton, by simply using:
+
+ modprobe $TCM_NEW_MOD
+ mkdir -p /sys/kernel/config/target/$TCM_NEW_MOD
+
+This script will create a new drivers/target/$TCM_NEW_MOD/, and will do the following
+
+ *) Generate new API callers for drivers/target/target_core_fabric_configs.c logic
+ ->make_nodeacl(), ->drop_nodeacl(), ->make_tpg(), ->drop_tpg()
+ ->make_wwn(), ->drop_wwn(). These are created into $TCM_NEW_MOD/$TCM_NEW_MOD_configfs.c
+ *) Generate basic infrastructure for loading/unloading LKMs and TCM/ConfigFS fabric module
+ using a skeleton struct target_core_fabric_ops API template.
+ *) Based on user defined T10 Proto_Ident for the new fabric module being built,
+ the TransportID / Initiator and Target WWPN related handlers for
+ SPC-3 persistent reservation are automatically generated in $TCM_NEW_MOD/$TCM_NEW_MOD_fabric.c
+ using drivers/target/target_core_fabric_lib.c logic.
+ *) NOP API calls for all other Data I/O path and fabric dependent attribute logic
+ in $TCM_NEW_MOD/$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_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
+
+At the end of tcm_mod_builder.py. the script will ask to add the following
+line to drivers/target/Kbuild:
+
+ obj-$(CONFIG_TCM_NAB5000) += tcm_nab5000/
+
+and the same for drivers/target/Kconfig:
+
+ source "drivers/target/tcm_nab5000/Kconfig"
+
+*) Run 'make menuconfig' and select the new CONFIG_TCM_NAB5000 item:
+
+ <M> TCM_NAB5000 fabric module
+
+*) Build using 'make modules', once completed you will have:
+
+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
+
+*) Load the new module, create a lun_0 configfs group, and add new TCM Core
+ IBLOCK backstore symlink to port:
+
+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
+
+----------------------------------------------------------------------
+
+Future TODO items:
+
+ *) Add more T10 proto_idents
+ *) Make tcm_mod_dump_fabric_ops() smarter and generate function pointer
+ defs directly from include/target/target_core_fabric_ops.h:struct target_core_fabric_ops
+ structure members.
+
+October 5th, 2010
+Nicholas A. Bellinger <nab@linux-iscsi.org>

drivers/Kconfig

@@ -26,6 +26,8 @@ source "drivers/ata/Kconfig"
 
 source "drivers/md/Kconfig"
 
+source "drivers/target/Kconfig"
+
 source "drivers/message/fusion/Kconfig"
 
 source "drivers/firewire/Kconfig"

drivers/Makefile

@@ -46,6 +46,7 @@ obj-y += macintosh/
 obj-$(CONFIG_IDE) += ide/
 obj-$(CONFIG_SCSI) += scsi/
 obj-$(CONFIG_ATA) += ata/
+obj-$(CONFIG_TARGET_CORE) += target/
 obj-$(CONFIG_MTD) += mtd/
 obj-$(CONFIG_SPI) += spi/
 obj-y += net/

drivers/target/Kconfig

@@ -0,0 +1,32 @@
+
+menuconfig TARGET_CORE
+ tristate "Generic Target Core Mod (TCM) and ConfigFS Infrastructure"
+ depends on SCSI && BLOCK
+ select CONFIGFS_FS
+ default n
+ help
+ Say Y or M here to enable the TCM Storage Engine and ConfigFS enabled
+ control path for target_core_mod. This includes built-in TCM RAMDISK
+ subsystem logic for virtual LUN 0 access
+
+if TARGET_CORE
+
+config TCM_IBLOCK
+ tristate "TCM/IBLOCK Subsystem Plugin for Linux/BLOCK"
+ help
+ Say Y here to enable the TCM/IBLOCK subsystem plugin for non-buffered
+ access to Linux/Block devices using BIO
+
+config TCM_FILEIO
+ tristate "TCM/FILEIO Subsystem Plugin for Linux/VFS"
+ help
+ Say Y here to enable the TCM/FILEIO subsystem plugin for buffered
+ access to Linux/VFS struct file or struct block_device
+
+config TCM_PSCSI
+ tristate "TCM/pSCSI Subsystem Plugin for Linux/SCSI"
+ help
+ Say Y here to enable the TCM/pSCSI subsystem plugin for non-buffered
+ passthrough access to Linux/SCSI device
+
+endif

drivers/target/Makefile

@@ -0,0 +1,24 @@
+EXTRA_CFLAGS += -I$(srctree)/drivers/target/ -I$(srctree)/drivers/scsi/
+
+target_core_mod-y := target_core_configfs.o \
+ target_core_device.o \
+ target_core_fabric_configfs.o \
+ target_core_fabric_lib.o \
+ target_core_hba.o \
+ target_core_pr.o \
+ target_core_alua.o \
+ target_core_scdb.o \
+ target_core_tmr.o \
+ target_core_tpg.o \
+ target_core_transport.o \
+ target_core_cdb.o \
+ target_core_ua.o \
+ target_core_rd.o \
+ target_core_mib.o
+
+obj-$(CONFIG_TARGET_CORE) += target_core_mod.o
+
+# Subsystem modules
+obj-$(CONFIG_TCM_IBLOCK) += target_core_iblock.o
+obj-$(CONFIG_TCM_FILEIO) += target_core_file.o
+obj-$(CONFIG_TCM_PSCSI) += target_core_pscsi.o