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,URIBL_BLOCKED,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 1E349C07E9D for ; Thu, 22 Jul 2021 03:35:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2F1F60FF4 for ; Thu, 22 Jul 2021 03:35:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231160AbhGVCzW (ORCPT ); Wed, 21 Jul 2021 22:55:22 -0400 Received: from mail-pj1-f42.google.com ([209.85.216.42]:54936 "EHLO mail-pj1-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231163AbhGVCzV (ORCPT ); Wed, 21 Jul 2021 22:55:21 -0400 Received: by mail-pj1-f42.google.com with SMTP id j1so2550185pjj.4 for ; Wed, 21 Jul 2021 20:35:56 -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=tRzuh0w47yQoCM3k02xB3WQ2QEgPkeHzrmD4Ibxw350=; b=j+s+Ji/9h7Ehjr4GQ/ac0AorEsoCUx6Pbju75kAJLKlkuogcHdojGkcNbSsFzP94ox JaBecXH2+TVzd1LhKKRH6vQS3D3wWdQ152PVr9I7Zm3S2tBhHCdCaa/FvASAuXuUHUiP G520Qb75YJMgtdD4LBdCL/IIMdFnwyEq1yzHUU8YuP8wUZOgs8PAo0644MxYxTzE7JtB TZ0epBkQxDD9hK8J2upFxwaCrgSQakkd9Dp8Ab+MZVY35fY0b+LZeHZjPKgIVwaemmNM GWPZgh6stu8seC45yFuRKRDDv/aQBa9yup+Mm39B5JXNsDxW+8Dxrs6aFTPizXU0L6C6 ND+g== X-Gm-Message-State: AOAM533sBbUBO2julkHDeK+4eT2xpuqFPilAwlCrONh4CS5RgTtJJZ1v DYB622CpLKYiow5g/iP5z4U= X-Google-Smtp-Source: ABdhPJwYhE15aKNZhURc9XUgx+U2lwsK878FdL9NAVhd488TvCV0KBI8JM1u7FcNyPvzdwSspyjZYw== X-Received: by 2002:a65:690f:: with SMTP id s15mr27735409pgq.21.1626924955007; Wed, 21 Jul 2021 20:35:55 -0700 (PDT) Received: from asus.hsd1.ca.comcast.net ([2601:647:4000:d7:30e2:954a:f4a0:3224]) by smtp.gmail.com with ESMTPSA id n6sm32060258pgb.60.2021.07.21.20.35.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Jul 2021 20:35:54 -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 v3 15/18] scsi: ufs: Request sense data asynchronously Date: Wed, 21 Jul 2021 20:34:36 -0700 Message-Id: <20210722033439.26550-16-bvanassche@acm.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210722033439.26550-1-bvanassche@acm.org> References: <20210722033439.26550-1-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 c35e101c5834..75730a43fcca 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -7820,8 +7820,39 @@ 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_DRV_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) { @@ -7849,7 +7880,7 @@ 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) @@ -8444,35 +8475,6 @@ 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