From patchwork Wed May 6 14:34:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Veerabhadrarao Badiganti X-Patchwork-Id: 11531311 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C39B3913 for ; Wed, 6 May 2020 14:35:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC12D208E4 for ; Wed, 6 May 2020 14:35:13 +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="d3o6Lrqy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729075AbgEFOfC (ORCPT ); Wed, 6 May 2020 10:35:02 -0400 Received: from mail26.static.mailgun.info ([104.130.122.26]:21732 "EHLO mail26.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729073AbgEFOfB (ORCPT ); Wed, 6 May 2020 10:35:01 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1588775700; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=31i/QBZ+llMFh/7pc5B6BkBKk7K9R8oLXOgWY0W7TZE=; b=d3o6LrqyqPZQBKvF/gBfFRMhHvmxoh1OM+t+/uJLIFzvsp8TbtKpi1MEV7Y0d5MABYUdzkwg 0vd0fZq9blBPc5eguxUrgcow5YL/ryprv+E9cGLJQXh+MmUUredh15rVgYkbUUc6nBby0NI4 ou9dgQk7W1v5KC2bEqSevXCSceg= 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 5eb2cb14.7ff7e8760180-smtp-out-n05; Wed, 06 May 2020 14:35:00 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id EF50CC432C2; Wed, 6 May 2020 14:34:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=2.0 tests=ALL_TRUSTED,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.0 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 C6FF7C433D2; Wed, 6 May 2020 14:34:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org C6FF7C433D2 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 , , Baolin Wang , Yoshihiro Shimoda , Andreas Koop , Thomas Gleixner Subject: [PATCH V1 2/2] mmc: core: Fix recursive locking issue in CQE recovery path Date: Wed, 6 May 2020 20:04:03 +0530 Message-Id: <1588775643-18037-3-git-send-email-vbadigan@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1588775643-18037-1-git-send-email-vbadigan@codeaurora.org> References: <1588775643-18037-1-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: # v4.19+ Suggested-by: Sahitya Tummala Signed-off-by: Sarthak Garg --- drivers/mmc/core/queue.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 25bee3d..72bef39 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) */ @@ -131,12 +131,13 @@ static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req, spin_lock_irqsave(&mq->lock, flags); - if (mq->recovery_needed || !mq->use_cqe || host->hsq_enabled) + if (mq->recovery_needed || !mq->use_cqe || host->hsq_enabled) { ret = BLK_EH_RESET_TIMER; - else + spin_unlock_irqrestore(&mq->lock, flags); + } else { + spin_unlock_irqrestore(&mq->lock, flags); ret = mmc_cqe_timed_out(req); - - spin_unlock_irqrestore(&mq->lock, flags); + } return ret; }