On 11/01/2010 05:15 PM, FUJITA Tomonori wrote: > On Mon, 01 Nov 2010 14:37:42 -0700 > "Nicholas A. Bellinger" <nab@xxxxxxxxxxxxxxx> wrote: > >> On Tue, 2010-11-02 at 06:05 +0900, FUJITA Tomonori wrote: >>> On Sat, 30 Oct 2010 16:13:54 -0700 >>> "Nicholas A. Bellinger" <nab@xxxxxxxxxxxxxxx> wrote: >>> >>>> From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> >>>> >>>> This patch takes tomo-san original commit 94fdb0196151 and changes a handful >>>> of important items wrt to the fabric configfs logic. >>>> >>>> Firstly, this patch introduces struct ibmvscsis_vdev and converts the >>>> VIO ibmvscsis_probe() and ibmvscsi_remove() callers to allocate/free >>>> struct ibmvscsis_vdev instead of the original usage of struct ibmvscsis_tpg >>>> which is intended to be allocated/freed respectively in ibmvscsis_make_tpg() >>>> and ibmvscsis_drop_tpg() fabric configfs handlers. >>> >>> What happens if an initiator sends a crq command before an user >>> creates a tpg? Or what happens if an initiator sends a crq command >>> after removing a tpg? >>> >> >> Hmmm, good point. So this would require ibmvscsis_queuecommand() to >> check internal some ibmvscsi_tpg state to determine availability, and >> reject incoming I/O otherwise. The other operation would be to just >> move crq queue creation/release for individual ibmvscsi_vdev into >> ibmvscsis_make_tpg() and ibmvscsis_drop_tpg(). > > You don't need to create/release rcq. I think that enable/disable vio > interrupts is enough. > >> I am suspecting the latter would bit slightly cleaner.. > > Probabably, however, I think that not returning any response to an > initiator makes the initiator stall for some time. > > >>>> Secondly, this patch changes the metadata that is used to determine the >>>> fabric WWN and TPGT (collectively the TCM VIO SRP endpoint) layout for >>>> /sys/kernel/config/target/ibmvscsis/$WWN/tpgt_$TPGT/. This patch will >>>> now use struct vio_dev->unit_address for $WWN, and dev_name(vio_dev->dev) >>>> for $TPGT. >>> >>> I don't care much about this but vio_dev->unit_address == >>> dev_name(vio_dev->dev), I think. See vio_register_device_node() in >>> arch/powerpc/kernel/vio.c. So it's odd a bit. >>> >> >> Hmmmm.. >> >>> ibmvscsis model doesn't strictly follow the SRP SCSI model; no port, >>> wwpn, etc. >>> >> >> Correct, which means we need to find a value to build a WWPN that is >> both unique to the individual POWER machine, and is persisent across >> reports.. > > I think that vio_dev->unit_address can be used to identify a nexus > uniquely. It's not WWPN though. It's a connection between an initiator > lpar and a target lpar. That's correct. The unit address uniquely defines the connection between the initiator and target vscsi adapters. It is persistent across reboots, but is not ww unique. Thanks, Brian -- Brian King Linux on Power Virtualization IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
