From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [PATCH 24/28] blk_end_request: changing ide normal caller (take 3) Date: Tue, 4 Dec 2007 14:47:00 +0100 Message-ID: <200712041447.00238.bzolnier@gmail.com> References: <20071130.183358.35360061.k-ueda@ct.jp.nec.com> <200712012353.05187.bzolnier@gmail.com> <20071203.181252.58460084.k-ueda@ct.jp.nec.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20071203.181252.58460084.k-ueda@ct.jp.nec.com> Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org To: Kiyoshi Ueda Cc: jens.axboe@oracle.com, bharrosh@panasas.com, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, dm-devel@redhat.com, j-nomura@ce.jp.nec.com List-Id: linux-ide@vger.kernel.org On Tuesday 04 December 2007, Kiyoshi Ueda wrote: > Hi Bartlomiej, > > On Sat, 1 Dec 2007 23:53:05 +0100, Bartlomiej Zolnierkiewicz wrote: > > On Saturday 01 December 2007, Kiyoshi Ueda wrote: > > > This patch converts "normal" parts of ide to use blk_end_request(). > > > > > > Signed-off-by: Kiyoshi Ueda > > > Signed-off-by: Jun'ichi Nomura > > > --- > > > drivers/ide/ide-cd.c | 6 +++--- > > > drivers/ide/ide-io.c | 17 ++++++----------- > > > 2 files changed, 9 insertions(+), 14 deletions(-) > > > > [...] > > > > > Index: 2.6.24-rc3-mm2/drivers/ide/ide-io.c > > > =================================================================== > > > --- 2.6.24-rc3-mm2.orig/drivers/ide/ide-io.c > > > +++ 2.6.24-rc3-mm2/drivers/ide/ide-io.c > > > @@ -78,14 +78,9 @@ static int __ide_end_request(ide_drive_t > > > ide_dma_on(drive); > > > } > > > > > > - if (!end_that_request_chunk(rq, uptodate, nr_bytes)) { > > > - add_disk_randomness(rq->rq_disk); > > > - if (dequeue) { > > > - if (!list_empty(&rq->queuelist)) > > > - blkdev_dequeue_request(rq); > > > + if (!__blk_end_request(rq, uptodate, nr_bytes)) { > > > + if (dequeue) > > > HWGROUP(drive)->rq = NULL; > > > - } > > > - end_that_request_last(rq, uptodate); > > > ret = 0; > > > } > > > > 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