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ecb27e7444
The patch below fixes the checkpatch complaints on kfree(): WARNING: kfree(NULL) is safe this check is probabally not required This patch has been verified as follows: - Verified that checkpatch does no longer complain about kfree(). - Verified that make -s clean && make -s iscsi scst && make -s -C srpt still works and does not trigger any new compiler warnings. - Checked that the patch generated by generate-kernel-patch still applies cleanly to the 2.6.25.4 kernel, and that the patched kernel tree still compiles, installs and boots fine, and that the iscsi-scst, ib_srpt, scst_disk and scst_vdisk modules still load. Note: I'm not sure any of the above verifications did trigger the code paths changed by this patch. Signed-off-by: Bart Van Assche <bart.vanassche@gmail.com> git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@402 d57e44dd-8a1f-0410-8b47-8ef2f437770f
SCSI RDMA Protocol (SRP) Target driver for Linux
=================================================
SRP Target driver is designed to work directly on top of OpenFabrics
OFED-1.x software stack (http://www.openfabrics.org) or Infiniband
drivers in Linux kernel tree (kernel.org). It also interfaces with
Generic SCSI target mid-level driver - SCST (http://scst.sourceforge.net)
NOTES: This SRP Target driver can only compile and work with IB driver
in Linux vanilla kernel. It does not compile and work with IB
driver in OFED-1.x packages
If you want to work with IB driver in OFED-1.x package, you should
read and follow instruction in README.ofed file
Installation
------------
$ make
$ make install
To minimize QUEUEFULL conditions, please apply scst_increase_max_tgt_cmds
patch and recompile scst
$ cd ~scst/trunk
$ patch -p0 < srpt/patches/scst_increasa_max_tgt_cmds.patch
$ make scst scst_install srpt srpt_install
How-to run
-----------
A. On srp target machine
1. Please refer to SCST's README for loading scst driver and its
dev_handlers drivers (scst_disk, scst_vdisk block or file IO mode, nullio, ...)
Example 1: working with real back-end scsi disks
a. modprobe scst
b. modprobe scst_disk
c. cat /proc/scsi_tgt/scsi_tgt
ibstor00:~ # cat /proc/scsi_tgt/scsi_tgt
Device (host:ch:id:lun or name) Device handler
0:0:0:0 dev_disk
4:0:0:0 dev_disk
5:0:0:0 dev_disk
6:0:0:0 dev_disk
7:0:0:0 dev_disk
Now you want to exclude the first scsi disk and expose the last 4 scsi disks as
IB/SRP luns for I/O
echo "add 4:0:0:0 0" >/proc/scsi_tgt/groups/Default/devices
echo "add 5:0:0:0 1" >/proc/scsi_tgt/groups/Default/devices
echo "add 6:0:0:0 2" >/proc/scsi_tgt/groups/Default/devices
echo "add 7:0:0:0 3" >/proc/scsi_tgt/groups/Default/devices
Example 2: working with VDISK FILEIO mode (using md0 device and file 10G-file)
a. modprobe scst
b. modprobe scst_vdisk
c. echo "open vdisk0 /dev/md0" > /proc/scsi_tgt/vdisk/vdisk
d. echo "open vdisk1 /10G-file" > /proc/scsi_tgt/vdisk/vdisk
e. echo "add vdisk0 0" >/proc/scsi_tgt/groups/Default/devices
f. echo "add vdisk1 1" >/proc/scsi_tgt/groups/Default/devices
Example 3: working with VDISK BLOCKIO mode (using md0 device, sda, and cciss/c1d0)
a. modprobe scst
b. modprobe scst_vdisk
c. echo "open vdisk0 /dev/md0 BLOCKIO" > /proc/scsi_tgt/vdisk/vdisk
d. echo "open vdisk1 /dev/sda BLOCKIO" > /proc/scsi_tgt/vdisk/vdisk
e. echo "open vdisk2 /dev/cciss/c1d0 BLOCKIO" > /proc/scsi_tgt/vdisk/vdisk
f. echo "add vdisk0 0" >/proc/scsi_tgt/groups/Default/devices
g. echo "add vdisk1 1" >/proc/scsi_tgt/groups/Default/devices
h. echo "add vdisk2 2" >/proc/scsi_tgt/groups/Default/devices
2. modprobe ib_srpt
B. On initiator machines you can manualy do the following steps:
1. modprobe ib_srp
2. ipsrpdm -c (to discover new SRP target)
3. echo <new target info> > /sys/class/infiniband_srp/srp-mthca0-1/add_target
4. fdisk -l (will show new discovered scsi disks)
Example:
Assume that you use port 1 of first HCA in the system ie. mthca0
[root@lab104 ~]# ibsrpdm -c -d /dev/infiniband/umad0
id_ext=0002c90200226cf4,ioc_guid=0002c90200226cf4,
dgid=fe800000000000000002c90200226cf5,pkey=ffff,service_id=0002c90200226cf4
[root@lab104 ~]# echo id_ext=0002c90200226cf4,ioc_guid=0002c90200226cf4,
dgid=fe800000000000000002c90200226cf5,pkey=ffff,service_id=0002c90200226cf4 >
/sys/class/infiniband_srp/srp-mthca0-1/add_target
OR
+ You can edit /etc/infiniband/openib.conf to load srp driver and srp HA daemon
automatically ie. set SRP_LOAD=yes, and SRPHA_ENABLE=yes
+ To set up and use high availability feature you need dm-multipath driver
and multipath tool
+ Please refer to OFED-1.x SRP's user manual for more in-details instructions
on how-to enable/use HA feature
TO DO
------
+ Stress test and stabilize the code
+ Performance tuning