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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 EDA68C64E7A for ; Mon, 16 Nov 2020 03:05:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BED6522280 for ; Mon, 16 Nov 2020 03:05:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726749AbgKPDFS (ORCPT ); Sun, 15 Nov 2020 22:05:18 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:42543 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726743AbgKPDFS (ORCPT ); Sun, 15 Nov 2020 22:05:18 -0500 Received: by mail-pf1-f195.google.com with SMTP id 131so2111331pfb.9; Sun, 15 Nov 2020 19:05:18 -0800 (PST) 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=iEm1L/1xTunB5Bi4Sc1aPphA3G474y7ilmOOODhkU2E=; b=ZPxtNTBeeuCd8aTx1stvJV63hlp1CpmKyr1uQrmufUSStH+zPQtmZGfG/+59ydy/Op SmNJZvUq6pqFaMQjLpJpXmmcIKirSg9TMZj6y7mvajszfBt3Rwt2oRot7RMRcAIkI1jC RyXUvyPMx0BZzRVe/7WawAwcFwqIraoJriABaUix26kTuwDs4om2W0SguzMCo+pdRjWK Y3Ckw+5pEgWAjdJYR4YxdmTgIjGa4ldSbQfsN7VWtFu8lR82VH8yrWOabixBYydqs4DJ LQC1hZodeL9ctLkXr17KQ7tgajA1ib8LmyQ/PwGj583pRZWUmeW5LMU2OLZIAI4aCa65 OFwg== X-Gm-Message-State: AOAM5310pPblFGIfDLKwgBFxHi2PeX2g3wlaIkfthoJ5sgyVmHXwrSGQ HxkOd16abYk7oJmSTZ6PUAY= X-Google-Smtp-Source: ABdhPJyjeSxvVm5IGFzxJYSH+QFNnZjdUr43f9e2y4+Bl/w+qSH5NOKZGrx7rl9yDZTkgfha8+e9mA== X-Received: by 2002:a63:2ad0:: with SMTP id q199mr157689pgq.257.1605495917683; Sun, 15 Nov 2020 19:05:17 -0800 (PST) Received: from asus.hsd1.ca.comcast.net (c-73-241-217-19.hsd1.ca.comcast.net. [73.241.217.19]) by smtp.gmail.com with ESMTPSA id r3sm17148131pjl.23.2020.11.15.19.05.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 Nov 2020 19:05:16 -0800 (PST) From: Bart Van Assche To: "Martin K . Petersen" Cc: "James E . J . Bottomley" , Jens Axboe , Christoph Hellwig , linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, Bart Van Assche , Alan Stern , Can Guo , Stanley Chu , Ming Lei , "Rafael J . Wysocki" Subject: [PATCH v2 5/9] scsi: Do not wait for a request in scsi_eh_lock_door() Date: Sun, 15 Nov 2020 19:04:55 -0800 Message-Id: <20201116030459.13963-6-bvanassche@acm.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201116030459.13963-1-bvanassche@acm.org> References: <20201116030459.13963-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org scsi_eh_lock_door() is the only function in the SCSI error handler that calls blk_get_request(). It is not guaranteed that a request is available when scsi_eh_lock_door() is called. Hence pass the BLK_MQ_REQ_NOWAIT flag to blk_get_request(). This patch has a second purpose, namely preventing that scsi_eh_lock_door() deadlocks if sdev->request_queue is frozen and if a SCSI command is submitted to a SCSI device through a second request queue that has not been frozen. A later patch will namely modify the SPI DV code such that sdev->requeust_queue is frozen during domain validation. Cc: Martin K. Petersen Reviewed-by: Alan Stern Cc: Can Guo Cc: Stanley Chu Cc: Ming Lei Cc: Rafael J. Wysocki Signed-off-by: Bart Van Assche --- drivers/scsi/scsi_error.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index d94449188270..6de6e1bf3dcb 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1993,7 +1993,12 @@ static void scsi_eh_lock_door(struct scsi_device *sdev) struct request *req; struct scsi_request *rq; - req = blk_get_request(sdev->request_queue, REQ_OP_SCSI_IN, 0); + /* + * It is not guaranteed that a request is available nor that + * sdev->request_queue is unfrozen. Hence the BLK_MQ_REQ_NOWAIT below. + */ + req = blk_get_request(sdev->request_queue, REQ_OP_SCSI_IN, + BLK_MQ_REQ_NOWAIT); if (IS_ERR(req)) return; rq = scsi_req(req);