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=-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 EB33DC11F69 for ; Thu, 1 Jul 2021 21:13:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC34F61406 for ; Thu, 1 Jul 2021 21:13:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234238AbhGAVQY (ORCPT ); Thu, 1 Jul 2021 17:16:24 -0400 Received: from mail-pf1-f169.google.com ([209.85.210.169]:33533 "EHLO mail-pf1-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233894AbhGAVQX (ORCPT ); Thu, 1 Jul 2021 17:16:23 -0400 Received: by mail-pf1-f169.google.com with SMTP id s14so7165384pfg.0 for ; Thu, 01 Jul 2021 14:13:52 -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=7NuK3lXUUdOrrf3Gm6bqMHeVFsXO1cnz9iNndZgcgy4=; b=Tul1DLwMw9fYbCzJwS4w7Cws5cWY/cpJ6sOeXlD93aUPY80FHD8ld3D8GVslG0pLGM LfsqL+tb56fNeJ+7Ry7aeGhsIbZ9KVr7R30QccgFpbYdeIWp8qf501BHw4eZp12KHzrQ RH2gXTP41vth0BOlSwDdcky0dvJ+yXMG61sUvZetCBnqYHxGlbaFVMY861x5WQRVUkbg wrkhKguu+eru4PlFdNt4SEesyMWW1b9CuTT++XVFXzYOJS0KI6NvD5AiRQkyYya6W68f FHDzcKYqV8eWCxdfnkAv3yLdEojYeIzBPcwFmgHWL9Uo3leP2WiWfeGXNY5euj1u0uvg 3Q8A== X-Gm-Message-State: AOAM530mMsu1T9LL8qI5s8Cj835LyuMMnpXaoy8f76hi+skks6/fyEM3 8e44XRa7alUD9zBf9eHKnyY= X-Google-Smtp-Source: ABdhPJzJX6inktHSgpaNd5YffrTr5zeniRZU5UkwgjUVp26GJd6Q2UrpWvph3JH8kJSo5cs1iMgcgQ== X-Received: by 2002:a63:e253:: with SMTP id y19mr1490557pgj.137.1625174032541; Thu, 01 Jul 2021 14:13:52 -0700 (PDT) Received: from asus.hsd1.ca.comcast.net ([2601:647:4000:d7:6a75:b07:a0d:8bd5]) by smtp.gmail.com with ESMTPSA id k25sm900832pfa.213.2021.07.01.14.13.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Jul 2021 14:13:51 -0700 (PDT) From: Bart Van Assche To: "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, Jaegeuk Kim , Bart Van Assche , Adrian Hunter , Stanley Chu , Can Guo , Asutosh Das , Avri Altman , "James E.J. Bottomley" , Matthias Brugger , Bean Huo Subject: [PATCH 19/21] ufs: Request sense data asynchronously Date: Thu, 1 Jul 2021 14:12:22 -0700 Message-Id: <20210701211224.17070-20-bvanassche@acm.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210701211224.17070-1-bvanassche@acm.org> References: <20210701211224.17070-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Clearing a unit attention synchronously from inside the UFS error handler may trigger the following deadlock: - ufshcd_err_handler() calls ufshcd_err_handling_unprepare() and the latter function calls ufshcd_clear_ua_wluns(). - ufshcd_clear_ua_wluns() submits a REQUEST SENSE command and that command activates the SCSI error handler. - The SCSI error handler calls ufshcd_host_reset_and_restore(). - ufshcd_host_reset_and_restore() executes the following code: ufshcd_schedule_eh_work(hba); flush_work(&hba->eh_work); This sequence results in a deadlock (circular wait). Fix this by requesting sense data asynchronously. Cc: Adrian Hunter Cc: Stanley Chu Cc: Can Guo Cc: Asutosh Das Cc: Avri Altman Signed-off-by: Bart Van Assche --- drivers/scsi/ufs/ufshcd.c | 64 ++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 31 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 250d46ab3584..a74862813140 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -7815,8 +7815,39 @@ static int ufshcd_add_lus(struct ufs_hba *hba) return ret; } +static void ufshcd_request_sense_done(struct request *rq, blk_status_t error) +{ + if (error != BLK_STS_OK) + pr_err("%s: REQUEST SENSE failed (%d)", __func__, error); + blk_put_request(rq); +} + static int -ufshcd_send_request_sense(struct ufs_hba *hba, struct scsi_device *sdp); +ufshcd_request_sense_async(struct ufs_hba *hba, struct scsi_device *sdev) +{ + /* + * From SPC-6: the REQUEST SENSE command with any allocation length + * clears the sense data. + */ + static const u8 cmd[6] = {REQUEST_SENSE, 0, 0, 0, 0, 0}; + struct scsi_request *rq; + struct request *req; + + req = blk_get_request(sdev->request_queue, REQ_OP_SCSI_IN, /*flags=*/0); + if (IS_ERR(req)) + return PTR_ERR(req); + + rq = scsi_req(req); + rq->cmd_len = ARRAY_SIZE(cmd); + memcpy(rq->cmd, cmd, rq->cmd_len); + rq->retries = 3; + req->timeout = 1 * HZ; + req->rq_flags |= RQF_PM | RQF_QUIET; + + blk_execute_rq_nowait(/*bd_disk=*/NULL, req, /*at_head=*/true, + ufshcd_request_sense_done); + return 0; +} static int ufshcd_clear_ua_wlun(struct ufs_hba *hba, u8 wlun) { @@ -7844,7 +7875,7 @@ static int ufshcd_clear_ua_wlun(struct ufs_hba *hba, u8 wlun) if (ret) goto out_err; - ret = ufshcd_send_request_sense(hba, sdp); + ret = ufshcd_request_sense_async(hba, sdp); scsi_device_put(sdp); out_err: if (ret) @@ -8439,35 +8470,6 @@ static void ufshcd_hba_exit(struct ufs_hba *hba) } } -static int -ufshcd_send_request_sense(struct ufs_hba *hba, struct scsi_device *sdp) -{ - unsigned char cmd[6] = {REQUEST_SENSE, - 0, - 0, - 0, - UFS_SENSE_SIZE, - 0}; - char *buffer; - int ret; - - buffer = kzalloc(UFS_SENSE_SIZE, GFP_KERNEL); - if (!buffer) { - ret = -ENOMEM; - goto out; - } - - ret = scsi_execute(sdp, cmd, DMA_FROM_DEVICE, buffer, - UFS_SENSE_SIZE, NULL, NULL, - msecs_to_jiffies(1000), 3, 0, RQF_PM, NULL); - if (ret) - pr_err("%s: failed with err %d\n", __func__, ret); - - kfree(buffer); -out: - return ret; -} - /** * ufshcd_set_dev_pwr_mode - sends START STOP UNIT command to set device * power mode