Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933803Ab0HLMrI (ORCPT ); Thu, 12 Aug 2010 08:47:08 -0400 Received: from hera.kernel.org ([140.211.167.34]:38358 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753678Ab0HLMoV (ORCPT ); Thu, 12 Aug 2010 08:44:21 -0400 From: Tejun Heo To: jaxboe@fusionio.com, linux-fsdevel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, hch@lst.de, James.Bottomley@suse.de, tytso@mit.edu, chris.mason@oracle.com, swhiteho@redhat.com, konishi.ryusuke@lab.ntt.co.jp, dm-devel@redhat.com, vst@vlnb.net, jack@suse.cz, rwheeler@redhat.com, hare@suse.de Cc: Tejun Heo Subject: [PATCH 05/11] block: misc cleanups in barrier code Date: Thu, 12 Aug 2010 14:41:25 +0200 Message-Id: <1281616891-5691-6-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1281616891-5691-1-git-send-email-tj@kernel.org> References: <1281616891-5691-1-git-send-email-tj@kernel.org> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 12 Aug 2010 12:43:52 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6796 Lines: 202 Make the following cleanups in preparation of barrier/flush update. * blk_do_ordered() declaration is moved from include/linux/blkdev.h to block/blk.h. * blk_do_ordered() now returns pointer to struct request, with %NULL meaning "try the next request" and ERR_PTR(-EAGAIN) "try again later". The third case will be dropped with further changes. * In the initialization of proxy barrier request, data direction is already set by init_request_from_bio(). Drop unnecessary explicit REQ_WRITE setting and move init_request_from_bio() above REQ_FUA flag setting. * add_request() is collapsed into __make_request(). These changes don't make any functional difference. Signed-off-by: Tejun Heo --- block/blk-barrier.c | 32 ++++++++++++++------------------ block/blk-core.c | 21 ++++----------------- block/blk.h | 7 +++++-- include/linux/blkdev.h | 1 - 4 files changed, 23 insertions(+), 38 deletions(-) diff --git a/block/blk-barrier.c b/block/blk-barrier.c index ed0aba5..f1be85b 100644 --- a/block/blk-barrier.c +++ b/block/blk-barrier.c @@ -110,9 +110,9 @@ static void queue_flush(struct request_queue *q, unsigned which) elv_insert(q, rq, ELEVATOR_INSERT_FRONT); } -static inline bool start_ordered(struct request_queue *q, struct request **rqp) +static inline struct request *start_ordered(struct request_queue *q, + struct request *rq) { - struct request *rq = *rqp; unsigned skip = 0; q->orderr = 0; @@ -149,11 +149,9 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp) /* initialize proxy request and queue it */ blk_rq_init(q, rq); - if (bio_data_dir(q->orig_bar_rq->bio) == WRITE) - rq->cmd_flags |= REQ_WRITE; + init_request_from_bio(rq, q->orig_bar_rq->bio); if (q->ordered & QUEUE_ORDERED_DO_FUA) rq->cmd_flags |= REQ_FUA; - init_request_from_bio(rq, q->orig_bar_rq->bio); rq->end_io = bar_end_io; elv_insert(q, rq, ELEVATOR_INSERT_FRONT); @@ -171,27 +169,26 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp) else skip |= QUEUE_ORDSEQ_DRAIN; - *rqp = rq; - /* * Complete skipped sequences. If whole sequence is complete, - * return false to tell elevator that this request is gone. + * return %NULL to tell elevator that this request is gone. */ - return !blk_ordered_complete_seq(q, skip, 0); + if (blk_ordered_complete_seq(q, skip, 0)) + rq = NULL; + return rq; } -bool blk_do_ordered(struct request_queue *q, struct request **rqp) +struct request *blk_do_ordered(struct request_queue *q, struct request *rq) { - struct request *rq = *rqp; const int is_barrier = rq->cmd_type == REQ_TYPE_FS && (rq->cmd_flags & REQ_HARDBARRIER); if (!q->ordseq) { if (!is_barrier) - return true; + return rq; if (q->next_ordered != QUEUE_ORDERED_NONE) - return start_ordered(q, rqp); + return start_ordered(q, rq); else { /* * Queue ordering not supported. Terminate @@ -199,8 +196,7 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp) */ blk_dequeue_request(rq); __blk_end_request_all(rq, -EOPNOTSUPP); - *rqp = NULL; - return false; + return NULL; } } @@ -211,14 +207,14 @@ bool blk_do_ordered(struct request_queue *q, struct request **rqp) /* Special requests are not subject to ordering rules. */ if (rq->cmd_type != REQ_TYPE_FS && rq != &q->pre_flush_rq && rq != &q->post_flush_rq) - return true; + return rq; /* Ordered by draining. Wait for turn. */ WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q)); if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q)) - *rqp = NULL; + rq = ERR_PTR(-EAGAIN); - return true; + return rq; } static void bio_end_empty_barrier(struct bio *bio, int err) diff --git a/block/blk-core.c b/block/blk-core.c index 3f802dd..ed8ef89 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1037,22 +1037,6 @@ void blk_insert_request(struct request_queue *q, struct request *rq, } EXPORT_SYMBOL(blk_insert_request); -/* - * add-request adds a request to the linked list. - * queue lock is held and interrupts disabled, as we muck with the - * request queue list. - */ -static inline void add_request(struct request_queue *q, struct request *req) -{ - drive_stat_acct(req, 1); - - /* - * elevator indicated where it wants this request to be - * inserted at elevator_merge time - */ - __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0); -} - static void part_round_stats_single(int cpu, struct hd_struct *part, unsigned long now) { @@ -1316,7 +1300,10 @@ get_rq: req->cpu = blk_cpu_to_group(smp_processor_id()); if (queue_should_plug(q) && elv_queue_empty(q)) blk_plug_device(q); - add_request(q, req); + + /* insert the request into the elevator */ + drive_stat_acct(req, 1); + __elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0); out: if (unplug || !queue_should_plug(q)) __generic_unplug_device(q); diff --git a/block/blk.h b/block/blk.h index 6e7dc87..874eb4e 100644 --- a/block/blk.h +++ b/block/blk.h @@ -51,6 +51,8 @@ static inline void blk_clear_rq_complete(struct request *rq) */ #define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) +struct request *blk_do_ordered(struct request_queue *q, struct request *rq); + static inline struct request *__elv_next_request(struct request_queue *q) { struct request *rq; @@ -58,8 +60,9 @@ static inline struct request *__elv_next_request(struct request_queue *q) while (1) { while (!list_empty(&q->queue_head)) { rq = list_entry_rq(q->queue_head.next); - if (blk_do_ordered(q, &rq)) - return rq; + rq = blk_do_ordered(q, rq); + if (rq) + return !IS_ERR(rq) ? rq : NULL; } if (!q->elevator->ops->elevator_dispatch_fn(q, 0)) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6003f7c..21baa19 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -867,7 +867,6 @@ extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); extern void blk_queue_flush(struct request_queue *q, unsigned int flush); extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); -extern bool blk_do_ordered(struct request_queue *, struct request **); extern unsigned blk_ordered_cur_seq(struct request_queue *); extern unsigned blk_ordered_req_seq(struct request *); extern bool blk_ordered_complete_seq(struct request_queue *, unsigned, int); -- 1.7.1 -- 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/