From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [PATCH 3/3] ide-{cd,floppy}: do not map all cmds to an sg Date: Thu, 12 Mar 2009 17:58:56 +0100 Message-ID: <200903121758.56808.bzolnier@gmail.com> References: <1236158216-23052-1-git-send-email-petkovbb@gmail.com> <200903111734.28956.bzolnier@gmail.com> <20090312071248.GA26881@liondog.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mu-out-0910.google.com ([209.85.134.188]:7173 "EHLO mu-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752669AbZCLQ5O (ORCPT ); Thu, 12 Mar 2009 12:57:14 -0400 In-Reply-To: <20090312071248.GA26881@liondog.tnic> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: petkovbb@gmail.com Cc: Tetsuo Handa , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org On Thursday 12 March 2009, Borislav Petkov wrote: > On Wed, Mar 11, 2009 at 05:34:28PM +0100, Bartlomiej Zolnierkiewicz wrote: > > On Tuesday 10 March 2009, Borislav Petkov wrote: > > > Hi, > > > > > > > If the mainline is broken sg fix can wait but to be honest I don't see much > > > > point in delaying it (it is an independent problem and the bugfix should be > > > > a completely safe one-liner). > > > > > > -- > > > From: Borislav Petkov > > > Date: Tue, 10 Mar 2009 07:04:52 +0100 > > > Subject: [PATCH] ide-floppy: do not map dataless cmds to an sg > > > > > > since it fails the virt_to_page() translation check with DEBUG_VIRTUAL > > > enabled. > > > > > > Signed-off-by: Borislav Petkov > > > > I applied it with some changes: > > > > > --- > > > drivers/ide/ide-atapi.c | 12 ++++++++++++ > > > drivers/ide/ide-floppy.c | 6 ++++-- > > > 2 files changed, 16 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c > > > index a5596a6..11a680c 100644 > > > --- a/drivers/ide/ide-atapi.c > > > +++ b/drivers/ide/ide-atapi.c > > > @@ -90,6 +90,12 @@ static void ide_queue_pc_head(ide_drive_t *drive, struct gendisk *disk, > > > rq->cmd_flags |= REQ_PREEMPT; > > > rq->buffer = (char *)pc; > > > rq->rq_disk = disk; > > > + > > > + if (pc->req_xfer) { > > > + rq->data = pc->buf; > > > + rq->data_len = pc->req_xfer; > > > + } > > > + > > > memcpy(rq->cmd, pc->c, 12); > > > if (drive->media == ide_tape) > > > rq->cmd[13] = REQ_IDETAPE_PC1; > > > @@ -112,6 +118,12 @@ int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk, > > > rq = blk_get_request(drive->queue, READ, __GFP_WAIT); > > > rq->cmd_type = REQ_TYPE_SPECIAL; > > > rq->buffer = (char *)pc; > > > + > > > + if (pc->req_xfer) { > > > + rq->data = pc->buf; > > > + rq->data_len = pc->req_xfer; > > > + } > > > + > > > memcpy(rq->cmd, pc->c, 12); > > > if (drive->media == ide_tape) > > > rq->cmd[13] = REQ_IDETAPE_PC1; > > > > ide-atapi.c part doesn't seem to be needed for fixing the issue > > so I removed it (IMO it would fit much better with your sg setup > > cleanup patch than this one) > > No, you need that part. And especially the rq->data assignment. > Take a look at ide_floppy_get_capacity() - it calls into > ide_queue_pc_tail() with pc->req_xfer == 255 resulting from the > ide_floppy_create_read_capacity_cmd(). However, the rq->data is still > NULL if you'd remove the chunk I added and you get [...] Ah I see it now but this is a separate issue from the original one (OOPS on DEBUG_VIRTUAL=y)! I somehow missed it (probably becasue patch description fails to mention this important information) and thus tried to be smart while merging the patch... Anyway, I replaced the patch in pata tree by your original one. Thanks, Bart