From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756854AbaIINI0 (ORCPT ); Tue, 9 Sep 2014 09:08:26 -0400 Received: from mail-pa0-f41.google.com ([209.85.220.41]:52110 "EHLO mail-pa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754157AbaIINGU (ORCPT ); Tue, 9 Sep 2014 09:06:20 -0400 From: Ming Lei To: Jens Axboe , linux-kernel@vger.kernel.org Cc: linux-scsi@vger.kernel.org, Christoph Hellwig , Ming Lei Subject: [PATCH 5/8] block: introduce blk_flush_queue to drive flush machinery Date: Tue, 9 Sep 2014 21:05:46 +0800 Message-Id: <1410267949-21904-6-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1410267949-21904-1-git-send-email-ming.lei@canonical.com> References: <1410267949-21904-1-git-send-email-ming.lei@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces 'struct blk_flush_queue' and puts all flush machinery related stuff into this strcuture, so that - flush implementation details aren't exposed to driver - it is easy to convert to per dispatch-queue flush machinery This patch is basically a mechanical replacement. Signed-off-by: Ming Lei --- block/blk-core.c | 3 +- block/blk-flush.c | 106 ++++++++++++++++++++++++++++++++---------------- block/blk-mq.c | 10 +++-- block/blk.h | 22 +++++++++- include/linux/blkdev.h | 10 +---- 5 files changed, 101 insertions(+), 50 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 222fe84..d278a30 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -390,11 +390,12 @@ static void __blk_drain_queue(struct request_queue *q, bool drain_all) * be drained. Check all the queues and counters. */ if (drain_all) { + struct blk_flush_queue *fq = blk_get_flush_queue(q); drain |= !list_empty(&q->queue_head); for (i = 0; i < 2; i++) { drain |= q->nr_rqs[i]; drain |= q->in_flight[i]; - drain |= !list_empty(&q->flush_queue[i]); + drain |= !list_empty(&fq->flush_queue[i]); } } diff --git a/block/blk-flush.c b/block/blk-flush.c index a59dd1a..894a149 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -28,7 +28,7 @@ * * The actual execution of flush is double buffered. Whenever a request * needs to execute PRE or POSTFLUSH, it queues at - * q->flush_queue[q->flush_pending_idx]. Once certain criteria are met, a + * fq->flush_queue[fq->flush_pending_idx]. Once certain criteria are met, a * flush is issued and the pending_idx is toggled. When the flush * completes, all the requests which were pending are proceeded to the next * step. This allows arbitrary merging of different types of FLUSH/FUA @@ -157,7 +157,7 @@ static bool blk_flush_queue_rq(struct request *rq, bool add_front) * completion and trigger the next step. * * CONTEXT: - * spin_lock_irq(q->queue_lock or q->mq_flush_lock) + * spin_lock_irq(q->queue_lock or fq->mq_flush_lock) * * RETURNS: * %true if requests were added to the dispatch queue, %false otherwise. @@ -166,7 +166,8 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq, int error) { struct request_queue *q = rq->q; - struct list_head *pending = &q->flush_queue[q->flush_pending_idx]; + struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx]; bool queued = false, kicked; BUG_ON(rq->flush.seq & seq); @@ -182,12 +183,12 @@ static bool blk_flush_complete_seq(struct request *rq, unsigned int seq, case REQ_FSEQ_POSTFLUSH: /* queue for flush */ if (list_empty(pending)) - q->flush_pending_since = jiffies; + fq->flush_pending_since = jiffies; list_move_tail(&rq->flush.list, pending); break; case REQ_FSEQ_DATA: - list_move_tail(&rq->flush.list, &q->flush_data_in_flight); + list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); queued = blk_flush_queue_rq(rq, true); break; @@ -222,17 +223,18 @@ static void flush_end_io(struct request *flush_rq, int error) bool queued = false; struct request *rq, *n; unsigned long flags = 0; + struct blk_flush_queue *fq = blk_get_flush_queue(q); if (q->mq_ops) { - spin_lock_irqsave(&q->mq_flush_lock, flags); + spin_lock_irqsave(&fq->mq_flush_lock, flags); flush_rq->tag = -1; } - running = &q->flush_queue[q->flush_running_idx]; - BUG_ON(q->flush_pending_idx == q->flush_running_idx); + running = &fq->flush_queue[fq->flush_running_idx]; + BUG_ON(fq->flush_pending_idx == fq->flush_running_idx); /* account completion of the flush request */ - q->flush_running_idx ^= 1; + fq->flush_running_idx ^= 1; if (!q->mq_ops) elv_completed_request(q, flush_rq); @@ -256,13 +258,13 @@ static void flush_end_io(struct request *flush_rq, int error) * directly into request_fn may confuse the driver. Always use * kblockd. */ - if (queued || q->flush_queue_delayed) { + if (queued || fq->flush_queue_delayed) { WARN_ON(q->mq_ops); blk_run_queue_async(q); } - q->flush_queue_delayed = 0; + fq->flush_queue_delayed = 0; if (q->mq_ops) - spin_unlock_irqrestore(&q->mq_flush_lock, flags); + spin_unlock_irqrestore(&fq->mq_flush_lock, flags); } /** @@ -273,33 +275,34 @@ static void flush_end_io(struct request *flush_rq, int error) * Please read the comment at the top of this file for more info. * * CONTEXT: - * spin_lock_irq(q->queue_lock or q->mq_flush_lock) + * spin_lock_irq(q->queue_lock or fq->mq_flush_lock) * * RETURNS: * %true if flush was issued, %false otherwise. */ static bool blk_kick_flush(struct request_queue *q) { - struct list_head *pending = &q->flush_queue[q->flush_pending_idx]; + struct blk_flush_queue *fq = blk_get_flush_queue(q); + struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx]; struct request *first_rq = list_first_entry(pending, struct request, flush.list); - struct request *flush_rq = q->flush_rq; + struct request *flush_rq = fq->flush_rq; /* C1 described at the top of this file */ - if (q->flush_pending_idx != q->flush_running_idx || list_empty(pending)) + if (fq->flush_pending_idx != fq->flush_running_idx || list_empty(pending)) return false; /* C2 and C3 */ - if (!list_empty(&q->flush_data_in_flight) && + if (!list_empty(&fq->flush_data_in_flight) && time_before(jiffies, - q->flush_pending_since + FLUSH_PENDING_TIMEOUT)) + fq->flush_pending_since + FLUSH_PENDING_TIMEOUT)) return false; /* * Issue flush and toggle pending_idx. This makes pending_idx * different from running_idx, which means flush is in flight. */ - q->flush_pending_idx ^= 1; + fq->flush_pending_idx ^= 1; blk_rq_init(q, flush_rq); if (q->mq_ops) @@ -331,6 +334,7 @@ static void mq_flush_data_end_io(struct request *rq, int error) struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; unsigned long flags; + struct blk_flush_queue *fq = blk_get_flush_queue(q); ctx = rq->mq_ctx; hctx = q->mq_ops->map_queue(q, ctx->cpu); @@ -339,10 +343,10 @@ static void mq_flush_data_end_io(struct request *rq, int error) * After populating an empty queue, kick it to avoid stall. Read * the comment in flush_end_io(). */ - spin_lock_irqsave(&q->mq_flush_lock, flags); + spin_lock_irqsave(&fq->mq_flush_lock, flags); if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error)) blk_mq_run_hw_queue(hctx, true); - spin_unlock_irqrestore(&q->mq_flush_lock, flags); + spin_unlock_irqrestore(&fq->mq_flush_lock, flags); } /** @@ -410,11 +414,13 @@ void blk_insert_flush(struct request *rq) rq->cmd_flags |= REQ_FLUSH_SEQ; rq->flush.saved_end_io = rq->end_io; /* Usually NULL */ if (q->mq_ops) { + struct blk_flush_queue *fq = blk_get_flush_queue(q); + rq->end_io = mq_flush_data_end_io; - spin_lock_irq(&q->mq_flush_lock); + spin_lock_irq(&fq->mq_flush_lock); blk_flush_complete_seq(rq, REQ_FSEQ_ACTIONS & ~policy, 0); - spin_unlock_irq(&q->mq_flush_lock); + spin_unlock_irq(&fq->mq_flush_lock); return; } rq->end_io = flush_data_end_io; @@ -478,34 +484,64 @@ EXPORT_SYMBOL(blkdev_issue_flush); static int blk_mq_init_flush(struct request_queue *q) { struct blk_mq_tag_set *set = q->tag_set; + struct blk_flush_queue *fq = blk_get_flush_queue(q); - spin_lock_init(&q->mq_flush_lock); + spin_lock_init(&fq->mq_flush_lock); - q->flush_rq = kzalloc(round_up(sizeof(struct request) + + fq->flush_rq = kzalloc(round_up(sizeof(struct request) + set->cmd_size, cache_line_size()), GFP_KERNEL); - if (!q->flush_rq) + if (!fq->flush_rq) return -ENOMEM; return 0; } -int blk_init_flush(struct request_queue *q) +static void blk_mq_exit_flush(struct request_queue *q) { - INIT_LIST_HEAD(&q->flush_queue[0]); - INIT_LIST_HEAD(&q->flush_queue[1]); - INIT_LIST_HEAD(&q->flush_data_in_flight); + struct blk_flush_queue *fq = blk_get_flush_queue(q); + kfree(fq->flush_rq); + kfree(fq); +} - if (q->mq_ops) - return blk_mq_init_flush(q); +int blk_init_flush(struct request_queue *q) +{ + int ret; + struct blk_flush_queue *fq = kzalloc(sizeof(*fq), GFP_KERNEL); - q->flush_rq = kzalloc(sizeof(struct request), GFP_KERNEL); - if (!q->flush_rq) + if (!fq) return -ENOMEM; + q->fq = fq; + INIT_LIST_HEAD(&fq->flush_queue[0]); + INIT_LIST_HEAD(&fq->flush_queue[1]); + INIT_LIST_HEAD(&fq->flush_data_in_flight); + + if (q->mq_ops) { + ret = blk_mq_init_flush(q); + if (ret) + goto failed; + } else { + ret = -ENOMEM; + fq->flush_rq = kzalloc(sizeof(struct request), GFP_KERNEL); + if (!fq->flush_rq) + goto failed; + } + return 0; + + failed: + kfree(fq); + q->fq = NULL; + return ret; } void blk_exit_flush(struct request_queue *q) { - kfree(q->flush_rq); + if (q->mq_ops) + blk_mq_exit_flush(q); + else { + struct blk_flush_queue *fq = blk_get_flush_queue(q); + kfree(fq->flush_rq); + kfree(fq); + } } diff --git a/block/blk-mq.c b/block/blk-mq.c index 706181a..7782d14 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -508,20 +508,22 @@ void blk_mq_kick_requeue_list(struct request_queue *q) } EXPORT_SYMBOL(blk_mq_kick_requeue_list); -static inline bool is_flush_request(struct request *rq, unsigned int tag) +static inline bool is_flush_request(struct request *rq, + struct blk_flush_queue *fq, unsigned int tag) { return ((rq->cmd_flags & REQ_FLUSH_SEQ) && - rq->q->flush_rq->tag == tag); + fq->flush_rq->tag == tag); } struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) { struct request *rq = tags->rqs[tag]; + struct blk_flush_queue *fq = blk_get_flush_queue(rq->q); - if (!is_flush_request(rq, tag)) + if (!is_flush_request(rq, fq, tag)) return rq; - return rq->q->flush_rq; + return fq->flush_rq; } EXPORT_SYMBOL(blk_mq_tag_to_rq); diff --git a/block/blk.h b/block/blk.h index 261f734..2637349 100644 --- a/block/blk.h +++ b/block/blk.h @@ -12,11 +12,28 @@ /* Max future timer expiry for timeouts */ #define BLK_MAX_TIMEOUT (5 * HZ) +struct blk_flush_queue { + unsigned int flush_queue_delayed:1; + unsigned int flush_pending_idx:1; + unsigned int flush_running_idx:1; + unsigned long flush_pending_since; + struct list_head flush_queue[2]; + struct list_head flush_data_in_flight; + struct request *flush_rq; + spinlock_t mq_flush_lock; +}; + extern struct kmem_cache *blk_requestq_cachep; extern struct kmem_cache *request_cachep; extern struct kobj_type blk_queue_ktype; extern struct ida blk_queue_ida; +static inline struct blk_flush_queue *blk_get_flush_queue( + struct request_queue *q) +{ + return q->fq; +} + static inline void __blk_get_queue(struct request_queue *q) { kobject_get(&q->kobj); @@ -91,6 +108,7 @@ void blk_insert_flush(struct request *rq); static inline struct request *__elv_next_request(struct request_queue *q) { struct request *rq; + struct blk_flush_queue *fq = blk_get_flush_queue(q); while (1) { if (!list_empty(&q->queue_head)) { @@ -113,9 +131,9 @@ static inline struct request *__elv_next_request(struct request_queue *q) * should be restarted later. Please see flush_end_io() for * details. */ - if (q->flush_pending_idx != q->flush_running_idx && + if (fq->flush_pending_idx != fq->flush_running_idx && !queue_flush_queueable(q)) { - q->flush_queue_delayed = 1; + fq->flush_queue_delayed = 1; return NULL; } if (unlikely(blk_queue_bypass(q)) || diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e267bf0..49f3461 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -36,6 +36,7 @@ struct request; struct sg_io_hdr; struct bsg_job; struct blkcg_gq; +struct blk_flush_queue; #define BLKDEV_MIN_RQ 4 #define BLKDEV_MAX_RQ 128 /* Default maximum */ @@ -455,14 +456,7 @@ struct request_queue { */ unsigned int flush_flags; unsigned int flush_not_queueable:1; - unsigned int flush_queue_delayed:1; - unsigned int flush_pending_idx:1; - unsigned int flush_running_idx:1; - unsigned long flush_pending_since; - struct list_head flush_queue[2]; - struct list_head flush_data_in_flight; - struct request *flush_rq; - spinlock_t mq_flush_lock; + struct blk_flush_queue *fq; struct list_head requeue_list; spinlock_t requeue_lock; -- 1.7.9.5