From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 27A53C56202 for ; Wed, 18 Nov 2020 01:12:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BAE352465E for ; Wed, 18 Nov 2020 01:12:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="xShNvBEf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728242AbgKRBMw (ORCPT ); Tue, 17 Nov 2020 20:12:52 -0500 Received: from z5.mailgun.us ([104.130.96.5]:21442 "EHLO z5.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727288AbgKRBMw (ORCPT ); Tue, 17 Nov 2020 20:12:52 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1605661971; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=xTyjQ9toNaO+YIybc97CIcLboXOhzdbqCV8FHhGdOaY=; b=xShNvBEfzb4io1h07RVEnHb+H2JaJmZbmshKkymAN+huDdDPyAcziSnI+txPtL359Sg85/9u f4pHl09GSCMV7GtnYgZwgY1zaikQuv3duGKeWTC/SBp8+j6hctTx0EJzDHQGChChwA9NdoYH it3Pzve/gWD77EE/TvMF5Id+pW8= X-Mailgun-Sending-Ip: 104.130.96.5 X-Mailgun-Sid: WyJlNmU5NiIsICJsaW51eC1zY3NpQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n03.prod.us-west-2.postgun.com with SMTP id 5fb4750fba0e43f35506012c (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 18 Nov 2020 01:12:47 GMT Sender: cang=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 928EAC43460; Wed, 18 Nov 2020 01:12:47 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: cang) by smtp.codeaurora.org (Postfix) with ESMTPSA id BC6EEC433C6; Wed, 18 Nov 2020 01:12:45 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 18 Nov 2020 09:12:45 +0800 From: Can Guo To: Bart Van Assche Cc: "Martin K . Petersen" , "James E . J . Bottomley" , Jens Axboe , Christoph Hellwig , linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, Alan Stern , Stanley Chu , Ming Lei , "Rafael J . Wysocki" , Martin Kepplinger Subject: Re: [PATCH v2 9/9] block: Do not accept any requests while suspended In-Reply-To: <20201116030459.13963-10-bvanassche@acm.org> References: <20201116030459.13963-1-bvanassche@acm.org> <20201116030459.13963-10-bvanassche@acm.org> Message-ID: <066dc92a56adcbf90fa5f7e460459f5e@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 2020-11-16 11:04, Bart Van Assche wrote: > From: Alan Stern > > blk_queue_enter() accepts BLK_MQ_REQ_PREEMPT independent of the runtime > power management state. Since SCSI domain validation no longer depends > on > this behavior, modify the behavior of blk_queue_enter() as follows: > - Do not accept any requests while suspended. > - Only process power management requests while suspending or resuming. > > Submitting BLK_MQ_REQ_PREEMPT requests to a device that is runtime- > suspended causes runtime-suspended block devices not to resume as they > should. The request which should cause a runtime resume instead gets > issued directly, without resuming the device first. Of course the > device > can't handle it properly, the I/O fails, and the device remains > suspended. > > The problem is fixed by checking that the queue's runtime-PM status > isn't RPM_SUSPENDED before allowing a request to be issued, and > queuing a runtime-resume request if it is. In particular, the inline > blk_pm_request_resume() routine is renamed blk_pm_resume_queue() and > the code is unified by merging the surrounding checks into the > routine. If the queue isn't set up for runtime PM, or there currently > is no restriction on allowed requests, the request is allowed. > Likewise if the BLK_MQ_REQ_PREEMPT flag is set and the status isn't > RPM_SUSPENDED. Otherwise a runtime resume is queued and the request > is blocked until conditions are more suitable. > > Cc: Can Guo > Cc: Stanley Chu > Cc: Ming Lei > Cc: Rafael J. Wysocki > Reported-and-tested-by: Martin Kepplinger > Signed-off-by: Alan Stern > Signed-off-by: Bart Van Assche Reviewed-by: Can Guo > [ bvanassche: modified commit message and removed Cc: stable because > without > the previous patches from this series this patch would break parallel > SCSI > domain validation ] > --- > block/blk-core.c | 6 +++--- > block/blk-pm.h | 14 +++++++++----- > 2 files changed, 12 insertions(+), 8 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index a00bce9f46d8..230880cbf8c8 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -440,7 +440,8 @@ int blk_queue_enter(struct request_queue *q, > blk_mq_req_flags_t flags) > * responsible for ensuring that that counter is > * globally visible before the queue is unfrozen. > */ > - if (pm || !blk_queue_pm_only(q)) { > + if ((pm && q->rpm_status != RPM_SUSPENDED) || > + !blk_queue_pm_only(q)) { > success = true; > } else { > percpu_ref_put(&q->q_usage_counter); > @@ -465,8 +466,7 @@ int blk_queue_enter(struct request_queue *q, > blk_mq_req_flags_t flags) > > wait_event(q->mq_freeze_wq, > (!q->mq_freeze_depth && > - (pm || (blk_pm_request_resume(q), > - !blk_queue_pm_only(q)))) || > + blk_pm_resume_queue(pm, q)) || > blk_queue_dying(q)); > if (blk_queue_dying(q)) > return -ENODEV; > diff --git a/block/blk-pm.h b/block/blk-pm.h > index ea5507d23e75..a2283cc9f716 100644 > --- a/block/blk-pm.h > +++ b/block/blk-pm.h > @@ -6,11 +6,14 @@ > #include > > #ifdef CONFIG_PM > -static inline void blk_pm_request_resume(struct request_queue *q) > +static inline int blk_pm_resume_queue(const bool pm, struct > request_queue *q) > { > - if (q->dev && (q->rpm_status == RPM_SUSPENDED || > - q->rpm_status == RPM_SUSPENDING)) > - pm_request_resume(q->dev); > + if (!q->dev || !blk_queue_pm_only(q)) > + return 1; /* Nothing to do */ > + if (pm && q->rpm_status != RPM_SUSPENDED) > + return 1; /* Request allowed */ > + pm_request_resume(q->dev); > + return 0; > } > > static inline void blk_pm_mark_last_busy(struct request *rq) > @@ -44,8 +47,9 @@ static inline void blk_pm_put_request(struct request > *rq) > --rq->q->nr_pending; > } > #else > -static inline void blk_pm_request_resume(struct request_queue *q) > +static inline int blk_pm_resume_queue(const bool pm, struct > request_queue *q) > { > + return 1; > } > > static inline void blk_pm_mark_last_busy(struct request *rq)