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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 08544C4167E for ; Fri, 10 Sep 2021 00:41:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E563561108 for ; Fri, 10 Sep 2021 00:41:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231633AbhIJAmT (ORCPT ); Thu, 9 Sep 2021 20:42:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:44188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229812AbhIJARv (ORCPT ); Thu, 9 Sep 2021 20:17:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D9DA2611C3; Fri, 10 Sep 2021 00:16:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233001; bh=JQ3M0VmSzNeZYdd0bN97o/E8ZQit8PGdocEvTNuEi6k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uYSdTSJpKUtDLEq5GEyRm7K0ae1nWVTI6a8bq69Z+coZv/KZLuwH0VV+LS8PPhaQP w+ctinxexhBCjEI46/VGh1FlKvKsgn9NXEisfRxpP4b4PS+4yMOuEFK3VOW2gRcbsz F+oo9ubKhofZY37HV8Q6Mhq3txPHWeWTucjKaSTpmyxy9PsQ/36qwBofTwsxOO6ZZk Xdz4SxOBS6x8pXUhUtgDJ4QAWwYQlc0HN4ZCcAGeUZBapYOZNUo0gPqplaRVN5o+xQ R7BnXNsuB3YyMRnHhZ9of2kB0D7PwjKL3hW/PGARyPsJfvWUgLcFPo3ztBw4emEEaY yOOxpShYBbOqw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Bart Van Assche , Adrian Hunter , Stanley Chu , Can Guo , Asutosh Das , Avri Altman , Bean Huo , "Martin K . Petersen" , Sasha Levin , linux-scsi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH AUTOSEL 5.14 30/99] scsi: ufs: Request sense data asynchronously Date: Thu, 9 Sep 2021 20:14:49 -0400 Message-Id: <20210910001558.173296-30-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910001558.173296-1-sashal@kernel.org> References: <20210910001558.173296-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Bart Van Assche [ Upstream commit ac1bc2ba060f9609972fb486073ebd9eab1ef3b6 ] 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. Link: https://lore.kernel.org/r/20210722033439.26550-16-bvanassche@acm.org Cc: Adrian Hunter Cc: Stanley Chu Cc: Can Guo Cc: Asutosh Das Cc: Avri Altman Reviewed-by: Bean Huo Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- 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 3350b0cff9ef..52731dffa624 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -7911,8 +7911,39 @@ 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) { @@ -7940,7 +7971,7 @@ 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) @@ -8535,35 +8566,6 @@ 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 -- 2.30.2