From patchwork Wed Mar 3 11:57:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jingbo Xu X-Patchwork-Id: 12116333 X-Patchwork-Delegate: snitzer@redhat.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FEB0C433E0 for ; Thu, 4 Mar 2021 14:42:10 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A813764F41 for ; Thu, 4 Mar 2021 14:42:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A813764F41 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=dm-devel-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-588-zjdR7RiHMBO7WKAVVN67uQ-1; Thu, 04 Mar 2021 09:42:06 -0500 X-MC-Unique: zjdR7RiHMBO7WKAVVN67uQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CC2C5CC62C; Thu, 4 Mar 2021 14:42:01 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A85485D71B; Thu, 4 Mar 2021 14:42:01 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 709CB1809C8D; Thu, 4 Mar 2021 14:42:01 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 123Bvut1003343 for ; Wed, 3 Mar 2021 06:57:57 -0500 Received: by smtp.corp.redhat.com (Postfix) id D63A01441B61; Wed, 3 Mar 2021 11:57:56 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast04.extmail.prod.ext.rdu2.redhat.com [10.11.55.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8DAAB1441B40 for ; Wed, 3 Mar 2021 11:57:56 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6AADF1151A84 for ; Wed, 3 Mar 2021 11:57:56 +0000 (UTC) Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-422-NTMnlID9OQanKQRWq9p1xg-1; Wed, 03 Mar 2021 06:57:53 -0500 X-MC-Unique: NTMnlID9OQanKQRWq9p1xg-1 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R201e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04420; MF=jefflexu@linux.alibaba.com; NM=1; PH=DS; RN=8; SR=0; TI=SMTPD_---0UQFBO8U_1614772663 Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0UQFBO8U_1614772663) by smtp.aliyun-inc.com(127.0.0.1); Wed, 03 Mar 2021 19:57:44 +0800 From: Jeffle Xu To: msnitzer@redhat.com, axboe@kernel.dk Date: Wed, 3 Mar 2021 19:57:31 +0800 Message-Id: <20210303115740.127001-4-jefflexu@linux.alibaba.com> In-Reply-To: <20210303115740.127001-1-jefflexu@linux.alibaba.com> References: <20210303115740.127001-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Mimecast-Bulk-Signature: yes X-Mimecast-Spam-Signature: bulk X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-loop: dm-devel@redhat.com X-Mailman-Approved-At: Thu, 04 Mar 2021 09:41:43 -0500 Cc: caspar@linux.alibaba.com, linux-block@vger.kernel.org, joseph.qi@linux.alibaba.com, dm-devel@redhat.com, mpatocka@redhat.com, io-uring@vger.kernel.org Subject: [dm-devel] [PATCH v5 03/12] block: add poll method to support bio-based IO polling X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com ->poll_fn was introduced in commit ea435e1b9392 ("block: add a poll_fn callback to struct request_queue") to support bio-based queues such as nvme multipath, but was later removed in commit 529262d56dbe ("block: remove ->poll_fn"). Given commit c62b37d96b6e ("block: move ->make_request_fn to struct block_device_operations") restore the possibility of bio-based IO polling support by adding an ->poll method to gendisk->fops. Make blk_mq_poll() specific to blk-mq, while blk_bio_poll() is originally a copy from blk_mq_poll(), and is specific to bio-based polling. Currently hybrid polling is not supported by bio-based polling. Signed-off-by: Jeffle Xu Reviewed-by: Mike Snitzer --- block/blk-core.c | 58 ++++++++++++++++++++++++++++++++++++++++++ block/blk-mq.c | 22 +--------------- include/linux/blk-mq.h | 1 + include/linux/blkdev.h | 1 + 4 files changed, 61 insertions(+), 21 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index fc60ff208497..6d7d53030d7c 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1119,6 +1119,64 @@ blk_qc_t submit_bio(struct bio *bio) } EXPORT_SYMBOL(submit_bio); + +static int blk_bio_poll(struct request_queue *q, blk_qc_t cookie, bool spin) +{ + long state; + struct gendisk *disk = queue_to_disk(q); + + state = current->state; + do { + int ret; + + ret = disk->fops->poll(q, cookie); + if (ret > 0) { + __set_current_state(TASK_RUNNING); + return ret; + } + + if (signal_pending_state(state, current)) + __set_current_state(TASK_RUNNING); + + if (current->state == TASK_RUNNING) + return 1; + if (ret < 0 || !spin) + break; + cpu_relax(); + } while (!need_resched()); + + __set_current_state(TASK_RUNNING); + return 0; +} + +/** + * blk_poll - poll for IO completions + * @q: the queue + * @cookie: cookie passed back at IO submission time + * @spin: whether to spin for completions + * + * Description: + * Poll for completions on the passed in queue. Returns number of + * completed entries found. If @spin is true, then blk_poll will continue + * looping until at least one completion is found, unless the task is + * otherwise marked running (or we need to reschedule). + */ +int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) +{ + if (!blk_qc_t_valid(cookie) || + !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) + return 0; + + if (current->plug) + blk_flush_plug_list(current->plug, false); + + if (queue_is_mq(q)) + return blk_mq_poll(q, cookie, spin); + else + return blk_bio_poll(q, cookie, spin); +} +EXPORT_SYMBOL_GPL(blk_poll); + /** * blk_cloned_rq_check_limits - Helper function to check a cloned request * for the new queue limits diff --git a/block/blk-mq.c b/block/blk-mq.c index d4d7c1caa439..214fa30b460a 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3852,30 +3852,11 @@ static bool blk_mq_poll_hybrid(struct request_queue *q, return blk_mq_poll_hybrid_sleep(q, rq); } -/** - * blk_poll - poll for IO completions - * @q: the queue - * @cookie: cookie passed back at IO submission time - * @spin: whether to spin for completions - * - * Description: - * Poll for completions on the passed in queue. Returns number of - * completed entries found. If @spin is true, then blk_poll will continue - * looping until at least one completion is found, unless the task is - * otherwise marked running (or we need to reschedule). - */ -int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) +int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, bool spin) { struct blk_mq_hw_ctx *hctx; long state; - if (!blk_qc_t_valid(cookie) || - !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) - return 0; - - if (current->plug) - blk_flush_plug_list(current->plug, false); - hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; /* @@ -3917,7 +3898,6 @@ int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) __set_current_state(TASK_RUNNING); return 0; } -EXPORT_SYMBOL_GPL(blk_poll); unsigned int blk_mq_rq_cpu(struct request *rq) { diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 2c473c9b8990..6a7b693b9917 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -615,6 +615,7 @@ static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio, } blk_qc_t blk_mq_submit_bio(struct bio *bio); +int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, bool spin); void blk_mq_hctx_set_fq_lock_class(struct blk_mq_hw_ctx *hctx, struct lock_class_key *key); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b81a9fe015ab..9dc83c30e7bc 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1866,6 +1866,7 @@ static inline void blk_ksm_unregister(struct request_queue *q) { } struct block_device_operations { blk_qc_t (*submit_bio) (struct bio *bio); + int (*poll)(struct request_queue *q, blk_qc_t cookie); int (*open) (struct block_device *, fmode_t); void (*release) (struct gendisk *, fmode_t); int (*rw_page)(struct block_device *, sector_t, struct page *, unsigned int);