From patchwork Mon Sep 25 20:29:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 9970469 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 53EFD6038E for ; Mon, 25 Sep 2017 20:29:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 464B528A45 for ; Mon, 25 Sep 2017 20:29:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3B42328A59; Mon, 25 Sep 2017 20:29:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D0A9428A53 for ; Mon, 25 Sep 2017 20:29:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966238AbdIYU3p (ORCPT ); Mon, 25 Sep 2017 16:29:45 -0400 Received: from esa2.hgst.iphmx.com ([68.232.143.124]:16623 "EHLO esa2.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966239AbdIYU3o (ORCPT ); Mon, 25 Sep 2017 16:29:44 -0400 X-IronPort-AV: E=Sophos;i="5.42,437,1500912000"; d="scan'208";a="150391988" Received: from sjappemgw12.hgst.com (HELO sjappemgw11.hgst.com) ([199.255.44.66]) by ob1.hgst.iphmx.com with ESMTP; 26 Sep 2017 04:39:58 +0800 Received: from thinkpad-bart.sdcorp.global.sandisk.com (HELO thinkpad-bart.int.fusionio.com) ([10.11.172.152]) by sjappemgw11.hgst.com with ESMTP; 25 Sep 2017 13:29:25 -0700 From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , "Martin K . Petersen" , =Oleksandr Natalenko , Bart Van Assche , Ming Lei , Hannes Reinecke , Johannes Thumshirn Subject: [PATCH v4 2/7] block: Make q_usage_counter also track legacy requests Date: Mon, 25 Sep 2017 13:29:19 -0700 Message-Id: <20170925202924.16603-3-bart.vanassche@wdc.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170925202924.16603-1-bart.vanassche@wdc.com> References: <20170925202924.16603-1-bart.vanassche@wdc.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Ming Lei This patch makes it possible to pause request allocation for the legacy block layer by calling blk_mq_freeze_queue() and blk_mq_unfreeze_queue(). Signed-off-by: Ming Lei [ bvanassche: Combined two patches into one, edited a comment and made sure REQ_NOWAIT is handled properly in blk_old_get_request() ] Signed-off-by: Bart Van Assche Cc: Ming Lei Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Johannes Thumshirn Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig --- block/blk-core.c | 12 ++++++++++++ block/blk-mq.c | 10 ++-------- 2 files changed, 14 insertions(+), 8 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index aebe676225e6..fef7133f8b0e 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -610,6 +610,9 @@ void blk_set_queue_dying(struct request_queue *q) } spin_unlock_irq(q->queue_lock); } + + /* Make blk_queue_enter() reexamine the DYING flag. */ + wake_up_all(&q->mq_freeze_wq); } EXPORT_SYMBOL_GPL(blk_set_queue_dying); @@ -1392,16 +1395,22 @@ static struct request *blk_old_get_request(struct request_queue *q, unsigned int op, gfp_t gfp_mask) { struct request *rq; + int ret = 0; WARN_ON_ONCE(q->mq_ops); /* create ioc upfront */ create_io_context(gfp_mask, q->node); + ret = blk_queue_enter(q, !(gfp_mask & __GFP_DIRECT_RECLAIM) || + (op & REQ_NOWAIT)); + if (ret) + return ERR_PTR(ret); spin_lock_irq(q->queue_lock); rq = get_request(q, op, NULL, gfp_mask); if (IS_ERR(rq)) { spin_unlock_irq(q->queue_lock); + blk_queue_exit(q); return rq; } @@ -1573,6 +1582,7 @@ void __blk_put_request(struct request_queue *q, struct request *req) blk_free_request(rl, req); freed_request(rl, sync, rq_flags); blk_put_rl(rl); + blk_queue_exit(q); } } EXPORT_SYMBOL_GPL(__blk_put_request); @@ -1854,8 +1864,10 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio) * Grab a free request. This is might sleep but can not fail. * Returns with the queue unlocked. */ + blk_queue_enter_live(q); req = get_request(q, bio->bi_opf, bio, GFP_NOIO); if (IS_ERR(req)) { + blk_queue_exit(q); __wbt_done(q->rq_wb, wb_acct); if (PTR_ERR(req) == -ENOMEM) bio->bi_status = BLK_STS_RESOURCE; diff --git a/block/blk-mq.c b/block/blk-mq.c index 98a18609755e..10c1f49f663d 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -125,7 +125,8 @@ void blk_freeze_queue_start(struct request_queue *q) freeze_depth = atomic_inc_return(&q->mq_freeze_depth); if (freeze_depth == 1) { percpu_ref_kill(&q->q_usage_counter); - blk_mq_run_hw_queues(q, false); + if (q->mq_ops) + blk_mq_run_hw_queues(q, false); } } EXPORT_SYMBOL_GPL(blk_freeze_queue_start); @@ -255,13 +256,6 @@ void blk_mq_wake_waiters(struct request_queue *q) queue_for_each_hw_ctx(q, hctx, i) if (blk_mq_hw_queue_mapped(hctx)) blk_mq_tag_wakeup_all(hctx->tags, true); - - /* - * If we are called because the queue has now been marked as - * dying, we need to ensure that processes currently waiting on - * the queue are notified as well. - */ - wake_up_all(&q->mq_freeze_wq); } bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)