Received: by 2002:a25:23cc:0:0:0:0:0 with SMTP id j195csp1444499ybj; Fri, 8 May 2020 01:15:25 -0700 (PDT) X-Google-Smtp-Source: APiQypJsRltlk8TYnKoSq6g92CbOfs+9a7oRufpBKdNU4MOlnWtPN/9o3DhgkKa89skM8MFYh7vr X-Received: by 2002:a05:6402:310b:: with SMTP id dc11mr1058022edb.143.1588925725640; Fri, 08 May 2020 01:15:25 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1588925725; cv=none; d=google.com; s=arc-20160816; b=DMqFCA40QjdVAwkSa7Jgx/DFFTYCJCL0IohhfcnsUC89xsEFARzuUInw8q8I2KZWdE n/lnmivue2ROWXgEdndl1BQgMozCpEmBKqvUuzJdrNwIeBw607W7hYMrR+auVH2nDevo SF3IyBkDcv4LlHtt7C2tGljskKPNKL/QyL4gIfaX5EZ6Bts9gN3trAQUmZsypWObZWzL yi3X6btCfqP2/f+WlI33Pdc02tl7A0vVhaLXwC2bFrhnDNnUWmkhsoZInln4POOQJtpC XQoWg9ERGTpPR/FCXBgEq7Foj7db2cllE9HUOTlcy1vQel/SCopKrJ8qooyFsrx7Nxw+ 5Ixg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=3qSRHUifjbk+HUdGENBz7hCntYdpN9AnCceyczmR5K8=; b=gFdNZmUp0aKdFBCXqC9tMpxwkbpIZHqhHJmWQHGTME5JV7DmXYSL2xyGn8FnQBvXcU hq/zxtZy34FQOj9odVSJ692QjcXoAJCyY/IMu0ubLBjN3cGQS89Xz7O8UzbvdOAF2JQN o4AY+iVtm+ZCqXSlk4neiUmBZ4nzG4m64XMUl3IYIWckhhq4gIkKhRkOKZ6X8H4R31ed JodTXyI4xt2FJmWH94gXoeqw1LPa7t1fUkrLjU5bSMnWNg/k+4wuWqtZ5XEcxoGE4JZ2 2S3V1rbirIN37QoR9n4Sy6gXUxnZizszoDVDS9zjhMR/xFAAS7ph5VtobweE8ukxRKoq dGJA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=bt2hFTGC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id k26si524914ejc.127.2020.05.08.01.15.03; Fri, 08 May 2020 01:15:25 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=bt2hFTGC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727030AbgEHIMp (ORCPT + 99 others); Fri, 8 May 2020 04:12:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726811AbgEHIMo (ORCPT ); Fri, 8 May 2020 04:12:44 -0400 Received: from mail-ua1-x944.google.com (mail-ua1-x944.google.com [IPv6:2607:f8b0:4864:20::944]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6EBF2C05BD0B for ; Fri, 8 May 2020 01:12:44 -0700 (PDT) Received: by mail-ua1-x944.google.com with SMTP id g35so344976uad.0 for ; Fri, 08 May 2020 01:12:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3qSRHUifjbk+HUdGENBz7hCntYdpN9AnCceyczmR5K8=; b=bt2hFTGCydhLSFbkAe8V54kz5sIGzjphQmKjLWusmdrLinuBd/8MNgqUGb3Vcvyfz4 5WOZZkzGVPztQScyPU4rjZYXRttK+2KB2vksoVsqbrTMEpvDkng2aUcmRdHrY1ckrhfd 18tHqkEVFkXmU6FCT6zwz0WSiYZibxyL3TCzt8NDe4m4ub1tG28FwJ97Q8hm/N2yGbvc 19amIqAYR6zjuPLLmi+xx8OtJDQErjZARzor78PKBD9d6sdve/6pYrrTmgAi94mr5oRr cr39P91QlCHlnRtJ0z4xHZP1yOOy3J40QslF60sEcdo1WD3f36NVZWUZ/73sT/9BrGrh p3eA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=3qSRHUifjbk+HUdGENBz7hCntYdpN9AnCceyczmR5K8=; b=aBekYvq1FXvGkRNLTUJ66b+kIrTL+CMuymLckWhe7rHcraYDWHy2Urj3B8+z0St0AR 0ltRNyucPe3i0dxFJGL0Uu0rKVal+o2UxIsLhFKjhsJzR8LCfuSUtpOxuclMz5UaSn2v mObEYl2rlCvOHtn+KYJD/qAocq5zyLMt9Q/tvOHyNb4Hl72hr/QjQrtlySAwDuryUitS x6cjQE59e28BnI8qJHOht8U6cqEnRFUS7rqIYcNjsbJsNRR2q68rwRn6tqyuFVYZuyV8 N2rO1Wh1toAi5FNJ6NMJCrZzP+3ML5b/NyOgsHJwnVS4by1gmadZxGprjN9nvdrBDcEJ 6Ukg== X-Gm-Message-State: AGi0PuYvW0l2iSex2f9sEZ2NhG3xU20SsNpuQVUVBJYB3d+FsFHmiVbY OnuLNRd1/mR/AlXuIzfh0vf7cAGuPAvRg06BUVKuaw== X-Received: by 2002:a9f:26e2:: with SMTP id 89mr950098uay.104.1588925563578; Fri, 08 May 2020 01:12:43 -0700 (PDT) MIME-Version: 1.0 References: <1588775643-18037-3-git-send-email-vbadigan@codeaurora.org> <1588868135-31783-1-git-send-email-vbadigan@codeaurora.org> In-Reply-To: <1588868135-31783-1-git-send-email-vbadigan@codeaurora.org> From: Ulf Hansson Date: Fri, 8 May 2020 10:12:07 +0200 Message-ID: Subject: Re: [PATCH V2] mmc: core: Fix recursive locking issue in CQE recovery path To: Veerabhadrarao Badiganti Cc: Adrian Hunter , Sahitya Tummala , "linux-mmc@vger.kernel.org" , Linux Kernel Mailing List , linux-arm-msm , Sarthak Garg , "# 4.0+" , Yoshihiro Shimoda , Baolin Wang , Kate Stewart , Allison Randal , Andreas Koop , Thomas Gleixner , Linus Walleij Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 7 May 2020 at 18:15, Veerabhadrarao Badiganti wrote: > > 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 Applied for fixes, thanks! Kind regards Uffe > --- > 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) > -- > Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc., is a member of Code Aurora Forum, a Linux Foundation Collaborative Project