Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755856AbZDNKCU (ORCPT ); Tue, 14 Apr 2009 06:02:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755758AbZDNKBj (ORCPT ); Tue, 14 Apr 2009 06:01:39 -0400 Received: from mail-bw0-f169.google.com ([209.85.218.169]:53877 "EHLO mail-bw0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754254AbZDNKBh (ORCPT ); Tue, 14 Apr 2009 06:01:37 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=date:from:to:cc:subject:message-id:reply-to:mail-followup-to :references:mime-version:content-type:content-disposition :in-reply-to:user-agent; b=iG7Eg5S1+YFrBmajLSZ/eU0U1Rqr8Ziw3kigMpiUJPKuW4GlQ6H4mC8y+b0G250SVy jyZzGnJAIs9uZ/JKTkJ0eF4Ghgx/mK0mMcPYTLuBl2f0KJH0Nq+rkjH1fcZX4jtlJTyx Qv7ZdLoOwcFhMyTY90ZzKN4dvj02zP5byO9hc= Date: Tue, 14 Apr 2009 12:01:31 +0200 From: Borislav Petkov To: FUJITA Tomonori Cc: tj@kernel.org, bharrosh@panasas.com, James.Bottomley@hansenpartnership.com, linux-scsi@vger.kernel.org, axboe@kernel.dk, bzolnier@gmail.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 14/17] scsi: replace custom rq mapping with blk_rq_map_kern_sgl() Message-ID: <20090414100131.GA14646@liondog.tnic> Reply-To: petkovbb@gmail.com Mail-Followup-To: petkovbb@gmail.com, FUJITA Tomonori , tj@kernel.org, bharrosh@panasas.com, James.Bottomley@hansenpartnership.com, linux-scsi@vger.kernel.org, axboe@kernel.dk, bzolnier@gmail.com, linux-kernel@vger.kernel.org References: <49E3080F.7080206@kernel.org> <20090413190747V.fujita.tomonori@lab.ntt.co.jp> <20090413125912.GA16337@liondog.tnic> <20090414093401V.fujita.tomonori@lab.ntt.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20090414093401V.fujita.tomonori@lab.ntt.co.jp> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6866 Lines: 214 (adding Bart to CC) On Tue, Apr 14, 2009 at 09:44:31AM +0900, FUJITA Tomonori wrote: > On Mon, 13 Apr 2009 14:59:12 +0200 > Borislav Petkov wrote: > > > Hi, > > > > On Mon, Apr 13, 2009 at 07:07:58PM +0900, FUJITA Tomonori wrote: > > > On Mon, 13 Apr 2009 18:38:23 +0900 > > > Tejun Heo wrote: > > > > > > > FUJITA Tomonori wrote: > > > > >> I thought that was agreed and done? What is left to do for that to go > > > > >> in. > > > > > > > > > > I've converted all the users (sg, st, osst). Nothing is left. So we > > > > > don't need this. > > > > > > > > Yeah, pulled it. Okay, so we can postpone diddling with request > > > > mapping for now. I'll re-post fixes only from this and the previous > > > > patchset and proceed with other patchsets. > > > > > > To be honest, I don't think that we can clean up the block > > > mapping. For example, blk_rq_map_kern_prealloc() in your patchset > > > doesn't look cleanup to me. It's just moving a hack from ide to the > > > block (well, I have to admit that I did the same thing when I > > > converted sg/st/osst...). > > > > Well, since blk_rq_map_kern_prealloc() is going to be used only in > > ide-cd (driver needs it to queue a sense request from within the irq > > handler) and since it is considered a hack I could try to move it out of > > the irq handler > > It's quite nice if you could do that. > > But I think that ide-atapi also needs blk_rq_map_kern_prealloc(). I'll look into that too. > > and do away only with blk_rq_map_kern() if that is more > > of an agreeable solution? > > Yeah, blk_rq_map_kern() is much proper. How's that for starters? I know, it is rough but it seems to work according to my initial testing. Basically, I opted for preallocating a sense request in the ->do_request routine and do that only on demand, i.e. I reinitialize it only if it got used in the irq handler. So in case you want to shove a rq sense in front of the queue, you simply use the already prepared one. Then in the irq handler it is being finished the usual ways (blk_end_request). Next time around you ->do_request, you reallocate it again since it got eaten in the last round. The good thing is that now I don't need all those static block layer structs in the driver (bio, bio_vec, etc) and do the preferred dynamic allocation instead. The patch is ontop of Tejun's series at http://git.kernel.org/?p=linux/kernel/git/tj/misc.git;a=shortlog;h=ide-phase1 with some small modifications in commit 15783b1443f810ae72cb5ccb3a3a3ccc3aeb8729 wrt proper sense buffer length. I'm sure there's enough room for improvement so please let me know if any objections/comments. --- diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index 35d0973..e689494 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -206,32 +206,21 @@ static void cdrom_analyze_sense_data(ide_drive_t *drive, ide_cd_log_error(drive->name, failed_command, sense); } -static void cdrom_queue_request_sense(ide_drive_t *drive, void *sense, - struct request *failed_command) +static struct request *ide_cd_prep_sense(ide_drive_t *drive) { struct cdrom_info *info = drive->driver_data; + void *sense = &info->sense_data; struct request *rq = &drive->request_sense_rq; - struct bio *bio = &drive->request_sense_bio; - struct bio_vec *bvec = drive->request_sense_bvec; - unsigned int bvec_len = ARRAY_SIZE(drive->request_sense_bvec); - unsigned sense_len = 18; - int error; + unsigned sense_len = sizeof(struct request_sense); ide_debug_log(IDE_DBG_SENSE, "enter"); - if (sense == NULL) { - sense = &info->sense_data; - sense_len = sizeof(struct request_sense); - } - memset(sense, 0, sense_len); - /* stuff the sense request in front of our current request */ blk_rq_init(NULL, rq); - error = blk_rq_map_kern_prealloc(drive->queue, rq, bio, bvec, bvec_len, - sense, sense_len, true); - BUG_ON(error); + if (blk_rq_map_kern(drive->queue, rq, sense, sense_len, __GFP_WAIT)) + return NULL; rq->rq_disk = info->disk; @@ -241,18 +230,17 @@ static void cdrom_queue_request_sense(ide_drive_t *drive, void *sense, rq->cmd_type = REQ_TYPE_SENSE; rq->cmd_flags |= REQ_PREEMPT; - /* NOTE! Save the failed command in "rq->special" */ - rq->special = (void *)failed_command; - - if (failed_command) - ide_debug_log(IDE_DBG_SENSE, "failed_cmd: 0x%x", - failed_command->cmd[0]); + return rq; +} - drive->hwif->rq = NULL; +static void ide_cd_queue_rq_sense(ide_drive_t *drive) +{ + BUG_ON(!drive->rq_sense); - elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 0); + elv_add_request(drive->queue, drive->rq_sense, ELEVATOR_INSERT_FRONT, 0); } + static void ide_cd_complete_failed_rq(ide_drive_t *drive, struct request *rq) { /* @@ -440,7 +428,7 @@ static int cdrom_decode_status(ide_drive_t *drive, u8 stat) /* if we got a CHECK_CONDITION status, queue a request sense command */ if (stat & ATA_ERR) - cdrom_queue_request_sense(drive, NULL, NULL); + ide_cd_queue_rq_sense(drive); return 1; end_request: @@ -454,7 +442,7 @@ end_request: hwif->rq = NULL; - cdrom_queue_request_sense(drive, rq->sense, rq); + ide_cd_queue_rq_sense(drive); return 1; } else return 2; @@ -788,6 +776,10 @@ out_end: ide_complete_rq(drive, uptodate ? 0 : -EIO, nsectors << 9); + /* our sense buffer got used, reset it the next time around. */ + if (sense) + drive->rq_sense = NULL; + if (sense && rc == 2) ide_error(drive, "request sense failure", stat); } @@ -901,6 +893,25 @@ static ide_startstop_t ide_cd_do_request(ide_drive_t *drive, struct request *rq, goto out_end; } + /* + * prepare request sense if it got used with the last rq + */ + if (!drive->rq_sense) { + drive->rq_sense = ide_cd_prep_sense(drive); + if (!drive->rq_sense) { + printk(KERN_ERR "%s: error prepping sense request!\n", + drive->name); + return ide_stopped; + } + } + + /* + * save the current request in case we'll be queueing a sense rq + * afterwards due to its potential failure. + */ + if (!blk_sense_request(rq)) + drive->rq_sense->special = (void *)rq; + memset(&cmd, 0, sizeof(cmd)); if (rq_data_dir(rq)) diff --git a/include/linux/ide.h b/include/linux/ide.h index c942533..4c2d310 100644 --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -605,6 +605,9 @@ struct ide_drive_s { struct request request_sense_rq; struct bio request_sense_bio; struct bio_vec request_sense_bvec[2]; + + /* current sense rq */ + struct request *rq_sense; }; typedef struct ide_drive_s ide_drive_t; -- Regards/Gruss, Boris. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/