Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764281AbXIKTMd (ORCPT ); Tue, 11 Sep 2007 15:12:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965435AbXIKTGy (ORCPT ); Tue, 11 Sep 2007 15:06:54 -0400 Received: from mx1.redhat.com ([66.187.233.31]:48940 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964942AbXIKTGv (ORCPT ); Tue, 11 Sep 2007 15:06:51 -0400 Date: Tue, 11 Sep 2007 15:05:45 -0400 (EDT) Message-Id: <20070911.150545.125541111.k-ueda@ct.jp.nec.com> To: jens.axboe@oracle.com, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, mike.miller@hp.com, grant.likely@secretlab.ca Cc: dm-devel@redhat.com, j-nomura@ce.jp.nec.com, k-ueda@ct.jp.nec.com Subject: [PATCH 26/27] blk_end_request: changing ide-cd (take 2) From: Kiyoshi Ueda X-Mailer: Mew version 3.3 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7844 Lines: 226 This patch converts ide-cd (cdrom_newpc_intr()) to use blk_end_request(). Due to the oddness of the driver, the patch adds a variant of the interface, blk_end_request_callback(). cdrom_newpc_intr() of ide-cd is the only function in the kernel tree which needs to call end_that_request_first() and end_that_request_last() separately. blk_end_request_callback() allows it to pass callback function to do something between end_that_request_first() and end_that_request_last(). ide-cd (cdrom_newpc_intr) needs to the followings: 1. call post_transform_command() to modify request contents 2. wait completing request until DRQ_STAT is cleared after end_that_request_first() and before end_that_request_last(). As for the second one, ide-cd will wait for the interrupt from device. So blk_end_request() has to return without completing request even if no leftover in the request. Signed-off-by: Kiyoshi Ueda Signed-off-by: Jun'ichi Nomura --- block/ll_rw_blk.c | 54 +++++++++++++++++++++++++++++++++ drivers/ide/ide-cd.c | 78 ++++++++++++++++++++++++++++++++++++++---------- include/linux/blkdev.h | 3 + 3 files changed, 118 insertions(+), 17 deletions(-) diff -rupN 25-ide-normal-caller-change/block/ll_rw_blk.c 26-ide-odd-caller-change/block/ll_rw_blk.c --- 25-ide-normal-caller-change/block/ll_rw_blk.c 2007-09-10 17:57:59.000000000 -0400 +++ 26-ide-odd-caller-change/block/ll_rw_blk.c 2007-09-10 18:21:27.000000000 -0400 @@ -3845,6 +3845,60 @@ int __blk_end_request(struct request *rq } EXPORT_SYMBOL_GPL(__blk_end_request); +/** + * blk_end_request_callback - Special helper function for the ide-cd driver + * @rq: the request being processed + * @uptodate: 1 for success, 0 for I/O error, < 0 for specific error + * @nr_bytes: number of bytes to complete + * @drv_callback: function called between completion of bios in the request + * and completion of the request. + * If the callback returns non 0, this helper returns without + * completion of the request. + * + * Description: + * Ends I/O on a number of bytes attached to @rq. + * If @rq has leftover, sets it up for the next range of segments. + * + * This special helper function for the ide-cd driver is used + * to complete the request only in cdrom_newpc_intr(). + * This interface will be removed when cdrom_newpc_intr() is rewritten. + * Don't use this interface in other places. + * + * Return: + * 0 - we are done with this request + * 1 - this request is not freed yet. + * this request still has pending buffers or + * the ide-cd driver doesn't want to finish this request yet. + **/ +int blk_end_request_callback(struct request *rq, int uptodate, int nr_bytes, + int (drv_callback)(struct request *)) +{ + struct request_queue *q = rq->q; + unsigned long flags = 0UL; + + if (blk_fs_request(rq) || blk_pc_request(rq)) { + if (__end_that_request_first(rq, uptodate, nr_bytes)) + return 1; + } + + /* Special feature for drivers/ide/ide-cd.c:cdrom_newpc_intr() */ + if (drv_callback && drv_callback(rq)) + return 1; + + /* + * No need to check the argument here because it is done + * in add_disk_randomness(). + */ + add_disk_randomness(rq->rq_disk); + + spin_lock_irqsave(q->queue_lock, flags); + complete_request(rq, uptodate); + spin_unlock_irqrestore(q->queue_lock, flags); + + return 0; +} +EXPORT_SYMBOL_GPL(blk_end_request_callback); + void blk_rq_bio_prep(struct request_queue *q, struct request *rq, struct bio *bio) { diff -rupN 25-ide-normal-caller-change/drivers/ide/ide-cd.c 26-ide-odd-caller-change/drivers/ide/ide-cd.c --- 25-ide-normal-caller-change/drivers/ide/ide-cd.c 2007-09-10 18:17:38.000000000 -0400 +++ 26-ide-odd-caller-change/drivers/ide/ide-cd.c 2007-09-10 18:21:27.000000000 -0400 @@ -1675,6 +1675,37 @@ static void post_transform_command(struc } } +/* + * Called from blk_end_request_callback() after the data of the request + * is completed and before the request is completed. + */ +static int cdrom_newpc_intr_dma_cb(struct request *rq) +{ + ide_drive_t *drive = rq->q->queuedata; + spinlock_t *ide_lock = rq->q->queue_lock; + unsigned long flags = 0UL; + + rq->data_len = 0; + post_transform_command(rq); + + spin_lock_irqsave(ide_lock, flags); + HWGROUP(drive)->rq = NULL; + spin_unlock_irqrestore(ide_lock, flags); + + return 0; +} + +/* + * Called from blk_end_request_callback() after the data of the request + * is completed and before the request is completed. + * By returning value '1', blk_end_request_callback() returns immediately + * without completing the request. + */ +static int cdrom_newpc_intr_dummy_cb(struct request *rq) +{ + return 1; +} + typedef void (xfer_func_t)(ide_drive_t *, void *, u32); /* @@ -1713,9 +1744,16 @@ static ide_startstop_t cdrom_newpc_intr( return ide_error(drive, "dma error", stat); } - end_that_request_chunk(rq, 1, rq->data_len); - rq->data_len = 0; - goto end_request; + /* + * post_transform_command() needs to be called after + * the data of the request is completed, since it may + * modify the data area of the request. + * So use the callback special feature of blk_end_request(). + */ + if (blk_end_request_callback(rq, 1, rq->data_len, + cdrom_newpc_intr_dma_cb)) + BUG(); + return ide_stopped; } /* @@ -1733,8 +1771,18 @@ static ide_startstop_t cdrom_newpc_intr( /* * If DRQ is clear, the command has completed. */ - if ((stat & DRQ_STAT) == 0) - goto end_request; + if ((stat & DRQ_STAT) == 0) { + if (!rq->data_len) + post_transform_command(rq); + + spin_lock_irqsave(&ide_lock, flags); + if (__blk_end_request(rq, 1, 0)) + BUG(); + HWGROUP(drive)->rq = NULL; + spin_unlock_irqrestore(&ide_lock, flags); + + return ide_stopped; + } /* * check which way to transfer data @@ -1787,7 +1835,14 @@ static ide_startstop_t cdrom_newpc_intr( rq->data_len -= blen; if (rq->bio) - end_that_request_chunk(rq, 1, blen); + /* + * The request can't be completed until DRQ is cleared. + * So complete the data, but don't complete the request + * using the dummy function for the callback feature + * of blk_end_request(). + */ + blk_end_request_callback(rq, 1, blen, + cdrom_newpc_intr_dummy_cb); else rq->data += blen; } @@ -1808,17 +1863,6 @@ static ide_startstop_t cdrom_newpc_intr( ide_set_handler(drive, cdrom_newpc_intr, rq->timeout, NULL); return ide_started; - -end_request: - if (!rq->data_len) - post_transform_command(rq); - - spin_lock_irqsave(&ide_lock, flags); - blkdev_dequeue_request(rq); - end_that_request_last(rq, 1); - HWGROUP(drive)->rq = NULL; - spin_unlock_irqrestore(&ide_lock, flags); - return ide_stopped; } static ide_startstop_t cdrom_write_intr(ide_drive_t *drive) diff -rupN 25-ide-normal-caller-change/include/linux/blkdev.h 26-ide-odd-caller-change/include/linux/blkdev.h --- 25-ide-normal-caller-change/include/linux/blkdev.h 2007-09-10 17:44:43.000000000 -0400 +++ 26-ide-odd-caller-change/include/linux/blkdev.h 2007-09-10 18:21:27.000000000 -0400 @@ -734,6 +734,9 @@ extern int end_that_request_chunk(struct extern void end_that_request_last(struct request *, int); extern void end_request(struct request *, int); extern void end_queued_request(struct request *, int); +extern int blk_end_request_callback(struct request *rq, int uptodate, + int nr_bytes, + int (drv_callback)(struct request *)); extern void blk_complete_request(struct request *); 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