Re: [PATCH 24/28] blk_end_request: changing ide normal caller(take 3)

From: Kiyoshi Ueda
Date: Tue Dec 04 2007 - 13:06:38 EST


Hi Bartlomiej,

On Tue, 4 Dec 2007 14:47:00 +0100, Bartlomiej Zolnierkiewicz wrote:
> > > Hmmm, this seems to change the old behavior (the request should
> > > be dequeued from the queue only if 'dequeue' variable is set)
> > > and AFAIR some error handling code (in ide-cd?) depends on the
> > > old behavior so please revisit this patch.
> >
> > blk_end_request() takes care of the dequeue like below,
> > so I think no problem. (Please see PATCH 01)
> >
> > > + /* rq->queuelist of dequeued request should be list_empty() */
> > > + if (!list_empty(&rq->queuelist))
> > > + blkdev_dequeue_request(rq);
> >
> > In the case of ide-cd,
> > o 'dequeue' variable is 1 only when the request is still linked
> > to the queue (i.e. rq->queuelist is not empty)
> > o 'dequeue' variable is 0 only when the request has already been
> > removed from the queue (i.e. rq->queuelist is empty)
> > So blk_end_request() can handle it correctly.
>
> It would be helpful to add the above explanation to a patch description.
>
> > If there are any drivers which don't want dequeue the queued request,
> > the code above would not work.
> > But, as far as I investigated, I have never seen such a requirement
> > in device drivers.
> >
> > Do you think that ide may still gets a problem for the 'dequeue'?
>
> Everything seems to be fine now.
>
> Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>

Thank you for the check.
OK, I'll add the explanation about the 'dequeue' to patch description.

Thanks,
Kiyoshi Ueda
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