From patchwork Sun Sep 6 01:22:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 11759423 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C4A6A92C for ; Sun, 6 Sep 2020 01:22:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5CD220DD4 for ; Sun, 6 Sep 2020 01:22:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728897AbgIFBWv (ORCPT ); Sat, 5 Sep 2020 21:22:51 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:44875 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728887AbgIFBWm (ORCPT ); Sat, 5 Sep 2020 21:22:42 -0400 Received: by mail-pg1-f196.google.com with SMTP id 7so6267833pgm.11; Sat, 05 Sep 2020 18:22:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=vzqwbvuEI0MUhU8xoJagSYikuR6h4EfX4KZRl8Z2nRE=; b=be2d8BktjGVZhGonAXyd9a2BOitu+sTzFq3hUzzRBapiboSZHoN8PiQuU1zh82oYzg Bw0IRcNykhzE5n5b0qCpbqfx4f6V5VAvRiGKqjy8DRILccDbPxWyC0TAmw4+Z5WMb7BI HGvq+9teKv5iaiUxrmWaMXnLciclad7IJRi7VVc2lpqjELHusYzh3IcFNYJuOIvxlZ8h g1mOQB1g/yQldHZ+wEaLjidwEIXrm5PAA6PpAkgC5rwUFks+sVdz6x+oYjE0oChsx7/H yLE4GH1Ney27LbLeols7jopjd8JQrlgnPW+oHvUNJ5JCd+PXk87fcbrQUaoiEwikPi57 hjZQ== X-Gm-Message-State: AOAM531aOa3TkA+R093Cy7mugz7l9qQeHCSGTNsJRWJ42L8ZvE6fDRM/ riCxksP3knLt+EQAsaBiqINMCX/n3WA= X-Google-Smtp-Source: ABdhPJwBbiTvZMj3ugSNOtOgzrsTYXIkmvVKxjy29lc9pPmPonlkUE5TKQJwkZ8J+U/xPgtVpK4TQg== X-Received: by 2002:a63:a08:: with SMTP id 8mr11182601pgk.300.1599355360874; Sat, 05 Sep 2020 18:22:40 -0700 (PDT) Received: from asus.hsd1.ca.comcast.net ([2601:647:4000:d7:cd46:435a:ac98:84de]) by smtp.gmail.com with ESMTPSA id 25sm3585165pjh.57.2020.09.05.18.22.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Sep 2020 18:22:40 -0700 (PDT) From: Bart Van Assche To: Jens Axboe , "Martin K . Petersen" , "James E . J . Bottomley" Cc: linux-block@vger.kernel.org, Christoph Hellwig , linux-scsi@vger.kernel.org, Alan Stern , Bart Van Assche , Can Guo , Stanley Chu , Ming Lei , "Rafael J . Wysocki" , Martin Kepplinger Subject: [PATCH 9/9] block: Do not accept any requests while suspended Date: Sat, 5 Sep 2020 18:22:19 -0700 Message-Id: <20200906012219.17893-10-bvanassche@acm.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200906012219.17893-1-bvanassche@acm.org> References: <20200906012219.17893-1-bvanassche@acm.org> MIME-Version: 1.0 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org 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 [ 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 c5a2f8173b1f..22c1c6e6c0e1 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -436,7 +436,8 @@ 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); @@ -461,8 +462,7 @@ 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)