Re: [PATCH] ibmvscsis: Move to struct ibmvscsis_vdev usage in fabric configfs handlers

[Brian King <brking@linux.vnet.ibm.com>]

On 11/01/2010 05:15 PM, FUJITA Tomonori wrote:
> On Mon, 01 Nov 2010 14:37:42 -0700
> "Nicholas A. Bellinger" <nab@linux-iscsi.org> 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@linux-iscsi.org> wrote:
>>>
>>>> From: Nicholas Bellinger <nab@linux-iscsi.org>
>>>>
>>>> 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.

Maybe I'm not following the conversation here, but if you just disable vio
interrupts, then any commands sent by a client LPAR would be seen to hang
from the client's perspective. If ibmvscsis doesn't have the CRQ registered,
then firmware will fail client commands with a response indicating the server
is not ready.

Thanks,

Brian


-- 
Brian King
Linux on Power Virtualization
IBM Linux Technology Center