Re: Regarding posted scsi midlyaer patchsets

Tejun Heo
2005-04-18T14:59:09Z

Hello, James.
Hello, Jens.

James Bottomley wrote:
> On Mon, 2005-04-18 at 07:41 +0900, Tejun Heo wrote:
>
>> As it's been almost a week since I posted scsi midlayer patchsets and
>>haven't heard anything yet, I've been wondering what's going on. Are
>>they under review or all dropped? If they are dropped, can you please
>>tell me why they are dropped?
>
>
> I have about four of them in the scsi-misc-2.6 tree, if you look.
>
> Your request path rewrite I already gave you feedback that I didn't want
> REQ_SOFTBARRIER in scsi ... it needs to be in the block submit API for
> special requests. Also, you have a patch for block in this code so I
> can't apply it without an ack from Jens. And all the rest of your
> patches depend on this one.

This thread started as an private inquiry to James regarding the status
of four patchsets I posted about a week ago. I'm replying publicly as I
think we can use some discussion. The four patchsets are... (in the
following order)

* timer updates
* REQ_SPECIAL/REQ_SOFTBARRIER usage change
* scsi_request_fn reimpl
* requeue path consolidation.

Accepted patches are

* scsi_cmnd->internal_timeout kill
* scsi_cmnd->serial_number_at_timeout
* remove volatile
* scsi_send_eh_cmnd() clean up

All four accepted patches are not included in any of above patchsets
and the timer update patchset doesn't depend on
REQ_SPECIAL/REQ_SOFTBARRIER usage change patchset, so please review the
timer update patchset.

And, James, regarding REQ_SOFTBARRIER, if the REQ_SOFTBARRIER thing can
be removed from SCSI midlayer, do you agree to change REQ_SPECIAL to
mean special requests? If so, I have three proposals.

* move REQ_SOFTBARRIER setting to right after the allocation of
scsi_cmnd in scsi_prep_fn(). This will be the only place where
REQ_SOFTBARRIER is used in SCSI midlayer, making it less pervasive.
* Or, make another API which sets REQ_SOFTBARRIER on requeue. maybe
blk_requeue_ordered_request()?
* Or, make blk_insert_request() not set REQ_SPECIAL on requeue. IMHO,
this is a bit too subtle.

I like #1 or #2. Jens, what do you think? Do you agree to remove
requeue feature from blk_insert_request()?

Thanks a lot. :-)

--
tejun