Re: [ANNOUNCE]: ConfigFS enabled Generic Target Mode and iSCSI TargetStack on v2.6.27-rc7

From: Vladislav Bolkhovitin
Date: Fri Oct 10 2008 - 13:49:41 EST

Nicholas A. Bellinger wrote:
> Ok, here is the commit:

http://git.kernel.org/?p=linux/kernel/git/nab/lio-core-2.6.git;a=commit;h=d1dc1c1da8375c1b9099166d7d93f7f45477f892

In the example I am using two iSCSI Initiators (one Debian and one
OpenSuse) that both have TPG LUN 0 and 1 mapped to their Initiator LUN 0
and 1 under $FABRIC/$IQN/tpgt_1.

Here is what it looks like from the CLI:

export TARGET=/sys/kernel/config/target/core/
export FABRIC=/sys/kernel/config/target/iscsi/

<Setup target_core_mod storage objects..>

DEF_IQN="iqn.2003-01.org.linux-iscsi.target.i686:sn.e475ed6fcdd0"

# The first mkdir(2) to $FABRIC will load iscsi_target_mod
mkdir -p "$FABRIC/$DEF_IQN/tpgt_1/np/172.16.201.137:3260"
# Create TPG LUN 0 and symlink $STORAGE_OBJECT from target_core_mod
mkdir -p "$FABRIC/$DEF_IQN/tpgt_1/lun/lun_0"
ln -s $TARGET/iblock_0/lvm_test0 "$FABRIC/$DEF_IQN/tpgt_1/lun/lun_0/lio_west_port"
# Create TPG LUN 1 and symlink $STORAGE_OBJECT from target_core_mod
mkdir -p "$FABRIC/$DEF_IQN/tpgt_1/lun/lun_1"
ln -s $TARGET/pscsi_0/sdd "$FABRIC/$DEF_IQN/tpgt_1/lun/lun_1/lio_east_port"

INITIATOR_DEBIAN="iqn.1993-08.org.debian:01:2dadf92d0ef"

# Create Node and two LUN ACL Symlinks for Debian Initiator
mkdir -p "$FABRIC/$DEF_IQN/tpgt_1/acls/$INITIATOR_DEBIAN/lun_0"
ln -s "$FABRIC/$DEF_IQN/tpgt_1/lun/lun_0" "$FABRIC/$DEF_IQN/tpgt_1/acls/$INITIATOR_DEBIAN/lun_0/."
mkdir -p "$FABRIC/$DEF_IQN/tpgt_1/acls/$INITIATOR_DEBIAN/lun_1"
ln -s "$FABRIC/$DEF_IQN/tpgt_1/lun/lun_1" "$FABRIC/$DEF_IQN/tpgt_1/acls/$INITIATOR_DEBIAN/lun_1/."

INITIATOR_SUSE="iqn.1996-04.de.suse:01:1661f9ee7b5"

# Create Node and two LUN ACL Symlinks for Suse Initiator
mkdir -p "$FABRIC/$DEF_IQN/tpgt_1/acls/$INITIATOR_SUSE/lun_0"
ln -s "$FABRIC/$DEF_IQN/tpgt_1/lun/lun_0" "$FABRIC/$DEF_IQN/tpgt_1/acls/$INITIATOR_SUSE/lun_0/."
mkdir -p "$FABRIC/$DEF_IQN/tpgt_1/acls/$INITIATOR_SUSE/lun_1"
ln -s "$FABRIC/$DEF_IQN/tpgt_1/lun/lun_1" "$FABRIC/$DEF_IQN/tpgt_1/acls/$INITIATOR_SUSE/lun_1/."

# Enable the $FABRIC endpoint so it can accept new iSCSI sessions.
echo 1 > $FABRIC/$DEF_IQN/tpgt_1/enable


And running....


target:/sys/kernel/config# tree $FABRIC
/sys/kernel/config/target/iscsi/
|-- iqn.2003-01.org.linux-iscsi.target.i686:sn.e475ed6fcdd0
| `-- tpgt_1
| |-- acls
| | |-- iqn.1993-08.org.debian:01:2dadf92d0ef
| | | |-- control
| | | |-- info
| | | |-- lun_0
| | | | `-- lun_0 -> ../../../../../../../target/iscsi/iqn.2003-01.org.linux-iscsi.target.i686:sn.e475ed6fcdd0/tpgt_1/lun/lun_0
| | | `-- lun_1
| | | `-- lun_1 -> ../../../../../../../target/iscsi/iqn.2003-01.org.linux-iscsi.target.i686:sn.e475ed6fcdd0/tpgt_1/lun/lun_1
| | `-- iqn.1996-04.de.suse:01:1661f9ee7b5
| | |-- control
| | |-- info
| | |-- lun_0
| | | `-- lun_0 -> ../../../../../../../target/iscsi/iqn.2003-01.org.linux-iscsi.target.i686:sn.e475ed6fcdd0/tpgt_1/lun/lun_0
| | `-- lun_1
| | `-- lun_1 -> ../../../../../../../target/iscsi/iqn.2003-01.org.linux-iscsi.target.i686:sn.e475ed6fcdd0/tpgt_1/lun/lun_1
| |-- control
| |-- enable
| |-- lun
| | |-- lun_0
| | | |-- control
| | | |-- info
| | | `-- lio_west_port -> ../../../../../../target/core/iblock_0/lvm_test0
| | `-- lun_1
| | |-- control
| | |-- info
| | `-- lio_east_port -> ../../../../../../target/core/pscsi_0/sdd
| `-- np
| `-- 172.16.201.137:3260
| `-- portal_info
`-- lio_version

20 directories, 12 files

Note that iSCSI Initiator LUN ACL Symlinks are done on a per TPGT
context and are only allowed for TPG LUNs under the same
$FABRIC/$IQN/$TPGT path.

I don't like that limitation. It looks completely artificial for me. And this approach doesn't address what to do if there is a connection from initiator, for which there is no corresponding ACL entry.

I again strongly suggest you to get familiar with SCST access control approach before making the next move. It's proved to be good and we should take all the best from it.

--------------------------------------------------------------------------------

Dump information for all running iSCSI Sessons on all iSCSI Target
endpoints..:

target:/sys/kernel/config# cat $FABRIC/iqn*/tpgt*/acls/*/info

InitiatorName: iqn.1993-08.org.debian:01:2dadf92d0ef
InitiatorAlias: ubuntu
LIO Session ID: 2 ISID: 0x00 02 3d 05 00 00 TSIH: 2 SessionType: Normal
Cmds in Session Pool: 1 Session State: TARG_SESS_STATE_LOGGED_IN
---------------------[iSCSI Session Values]-----------------------
CmdSN/WR : CmdSN/WC : ExpCmdSN : MaxCmdSN : ITT : TTT
0x00000010 0x00000010 0x00000042 0x00000051 0x090a0040 0x000000e7
----------------------[iSCSI Connections]-------------------------
CID: 0 Connection State: TARG_CONN_STATE_LOGGED_IN
Address 172.16.201.129 TCP StatSN: 0x0000006c
InitiatorName: iqn.1996-04.de.suse:01:1661f9ee7b5
InitiatorAlias: opensuse
LIO Session ID: 13 ISID: 0x00 02 3d 01 00 00 TSIH: 13 SessionType: Normal
Cmds in Session Pool: 1 Session State: TARG_SESS_STATE_LOGGED_IN
---------------------[iSCSI Session Values]-----------------------
CmdSN/WR : CmdSN/WC : ExpCmdSN : MaxCmdSN : ITT : TTT
0x00000010 0x00000010 0x00000022 0x00000031 0x040a0000 0x00000003
----------------------[iSCSI Connections]-------------------------
CID: 0 Connection State: TARG_CONN_STATE_LOGGED_IN
Address 172.16.201.136 TCP StatSN: 0x00000003


Anyways, you get the idea. The primary functionality is up for getting
ACLs iSCSI Initiator Nodes and LUNs symlinked to TPG LUNs symlinked to
$STORAGE_OBJECTs from target_core_mod. I will be continuing to convert
stuff from the IOCTL, mostly things that need to be made into configfs
attributes. I am going to focus on the getting the remaining stuff
under configfs up for iscsi_target_mod, and start looking at the much
larger todo item of seeing how we can merge target_core_mod and scst
core.. Please have a look and let me know what you think (espically the
target_core_mod parts), and I will pull the latest SCST code and start
looking at the FABRIC <-> TARGET you mentioned..

--nab



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