From patchwork Thu May 7 16:15:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Veerabhadrarao Badiganti X-Patchwork-Id: 210954 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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 43BE8C38A24 for ; Thu, 7 May 2020 16:16:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 17D182083B for ; Thu, 7 May 2020 16:16:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="UhTFXu5u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726636AbgEGQQA (ORCPT ); Thu, 7 May 2020 12:16:00 -0400 Received: from mail26.static.mailgun.info ([104.130.122.26]:34024 "EHLO mail26.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726222AbgEGQQA (ORCPT ); Thu, 7 May 2020 12:16:00 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588868159; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=w5NiSQ77D5gTRpc269gInIopQbtzyb+mp/b4/2QKUDE=; b=UhTFXu5ulu7Vd/LRB1gzux5OpXKN+1a7Fv7CPwPDaMddmIQr0hyuScgqlz+pIQW9In2PS7iS 2JxXhAcbGH222aY+Rwub05XeKtkjJrWy3LbDQkTKaFIaqMH5OYPYETiDhpLAbONO/zg5U/p+ UyLq8aAhBWL+pnylPy/fdDxIMVA= X-Mailgun-Sending-Ip: 104.130.122.26 X-Mailgun-Sid: WyJiYTcxMiIsICJsaW51eC1tbWNAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5eb43438.7f2b80073570-smtp-out-n04; Thu, 07 May 2020 16:15:52 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 7F4DAC44793; Thu, 7 May 2020 16:15:51 +0000 (UTC) Received: from vbadigan-linux.qualcomm.com (blr-c-bdr-fw-01_GlobalNAT_AllZones-Outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: vbadigan) by smtp.codeaurora.org (Postfix) with ESMTPSA id 4D35DC433F2; Thu, 7 May 2020 16:15:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4D35DC433F2 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=vbadigan@codeaurora.org From: Veerabhadrarao Badiganti To: adrian.hunter@intel.com, ulf.hansson@linaro.org Cc: stummala@codeaurora.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Sarthak Garg , , Yoshihiro Shimoda , Baolin Wang , Kate Stewart , Allison Randal , Andreas Koop , Thomas Gleixner , Linus Walleij Subject: [PATCH V2] mmc: core: Fix recursive locking issue in CQE recovery path Date: Thu, 7 May 2020 21:45:33 +0530 Message-Id: <1588868135-31783-1-git-send-email-vbadigan@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1588775643-18037-3-git-send-email-vbadigan@codeaurora.org> References: <1588775643-18037-3-git-send-email-vbadigan@codeaurora.org> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org From: Sarthak Garg Consider the following stack trace -001|raw_spin_lock_irqsave -002|mmc_blk_cqe_complete_rq -003|__blk_mq_complete_request(inline) -003|blk_mq_complete_request(rq) -004|mmc_cqe_timed_out(inline) -004|mmc_mq_timed_out mmc_mq_timed_out acquires the queue_lock for the first time. The mmc_blk_cqe_complete_rq function also tries to acquire the same queue lock resulting in recursive locking where the task is spinning for the same lock which it has already acquired leading to watchdog bark. Fix this issue with the lock only for the required critical section. Cc: Fixes: 1e8e55b67030 ("mmc: block: Add CQE support") Suggested-by: Sahitya Tummala Signed-off-by: Sarthak Garg --- drivers/mmc/core/queue.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 25bee3d..b5fd3bc 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -107,7 +107,7 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req) case MMC_ISSUE_DCMD: if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) { if (recovery_needed) - __mmc_cqe_recovery_notifier(mq); + mmc_cqe_recovery_notifier(mrq); return BLK_EH_RESET_TIMER; } /* No timeout (XXX: huh? comment doesn't make much sense) */ @@ -127,18 +127,13 @@ static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req, struct mmc_card *card = mq->card; struct mmc_host *host = card->host; unsigned long flags; - int ret; + bool ignore_tout; spin_lock_irqsave(&mq->lock, flags); - - if (mq->recovery_needed || !mq->use_cqe || host->hsq_enabled) - ret = BLK_EH_RESET_TIMER; - else - ret = mmc_cqe_timed_out(req); - + ignore_tout = mq->recovery_needed || !mq->use_cqe || host->hsq_enabled; spin_unlock_irqrestore(&mq->lock, flags); - return ret; + return ignore_tout ? BLK_EH_RESET_TIMER : mmc_cqe_timed_out(req); } static void mmc_mq_recovery_handler(struct work_struct *work)