From patchwork Wed Sep 22 12:51:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12510449 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 5F222C43217 for ; Wed, 22 Sep 2021 12:41:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4813761156 for ; Wed, 22 Sep 2021 12:41:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236049AbhIVMnO (ORCPT ); Wed, 22 Sep 2021 08:43:14 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:16229 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235986AbhIVMnN (ORCPT ); Wed, 22 Sep 2021 08:43:13 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.55]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4HDyZ76MvWz1DH7j; Wed, 22 Sep 2021 20:40:31 +0800 (CST) Received: from dggema762-chm.china.huawei.com (10.1.198.204) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.8; Wed, 22 Sep 2021 20:41:41 +0800 Received: from huawei.com (10.175.127.227) by dggema762-chm.china.huawei.com (10.1.198.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.8; Wed, 22 Sep 2021 20:41:41 +0800 From: Yu Kuai To: , CC: , , , , Subject: [PATCH 3/4] blk-throtl: introduce blk_throtl_cancel_bios() Date: Wed, 22 Sep 2021 20:51:14 +0800 Message-ID: <20210922125115.381752-4-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210922125115.381752-1-yukuai3@huawei.com> References: <20210922125115.381752-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggema762-chm.china.huawei.com (10.1.198.204) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org This function is used to cancel all throttled bios when queue is dying. Noted this modification is mainly from revertion of commit b77412372b68 ("blk-throttle: remove blk_throtl_drain"). Signed-off-by: Yu Kuai --- block/blk-throttle.c | 39 +++++++++++++++++++++++++++++++++++++++ block/blk.h | 2 ++ 2 files changed, 41 insertions(+) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 3892ead7a0b5..4227dcf2dd3b 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -2435,6 +2435,45 @@ static void tg_drain_bios(struct throtl_service_queue *parent_sq) } } +/** + * blk_throtl_cancel_bios - cancel throttled bios + * @q: request_queue to cancel throttled bios for + * + * This function is called when queue is dying, error all currently + * throttled bios on @q so that user threads that are waiting for the bios + * can exit. + */ +void blk_throtl_cancel_bios(struct request_queue *q) +{ + struct throtl_data *td = q->td; + struct blkcg_gq *blkg; + struct cgroup_subsys_state *pos_css; + struct bio *bio; + int rw; + + rcu_read_lock(); + + /* + * Drain each tg while doing post-order walk on the blkg tree, so + * that all bios are propagated to td->service_queue. It'd be + * better to walk service_queue tree directly but blkg walk is + * easier. + */ + blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) + tg_drain_bios(&blkg_to_tg(blkg)->service_queue); + + /* finally, transfer bios from top-level tg's into the td */ + tg_drain_bios(&td->service_queue); + + rcu_read_unlock(); + + /* all bios now should be in td->service_queue, cancel them */ + for (rw = READ; rw <= WRITE; rw++) + while ((bio = throtl_pop_queued(&td->service_queue.queued[rw], + NULL))) + bio_io_error(bio); +} + int blk_throtl_init(struct request_queue *q) { struct throtl_data *td; diff --git a/block/blk.h b/block/blk.h index 7d2a0ba7ed21..c407581a3a19 100644 --- a/block/blk.h +++ b/block/blk.h @@ -287,12 +287,14 @@ int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); * Internal throttling interface */ #ifdef CONFIG_BLK_DEV_THROTTLING +extern void blk_throtl_cancel_bios(struct request_queue *q); extern int blk_throtl_init(struct request_queue *q); extern void blk_throtl_exit(struct request_queue *q); extern void blk_throtl_register_queue(struct request_queue *q); extern void blk_throtl_charge_bio_split(struct bio *bio); bool blk_throtl_bio(struct bio *bio); #else /* CONFIG_BLK_DEV_THROTTLING */ +static inline void blk_throtl_cancel_bios(struct request_queue *q) { } static inline int blk_throtl_init(struct request_queue *q) { return 0; } static inline void blk_throtl_exit(struct request_queue *q) { } static inline void blk_throtl_register_queue(struct request_queue *q) { }