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=-7.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 7EA79C47E4D for ; Thu, 15 Jul 2021 12:28:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6659D611AB for ; Thu, 15 Jul 2021 12:28:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237220AbhGOMay (ORCPT ); Thu, 15 Jul 2021 08:30:54 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:38570 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230208AbhGOMax (ORCPT ); Thu, 15 Jul 2021 08:30:53 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 009C022A40; Thu, 15 Jul 2021 12:27:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1626352079; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CJEWq8qiVgvEoVbn4aLIKGb5fN74YYFkq1XScfceEpA=; b=UzW72TZ1XOcaU2Yrkabqq0GrXcQuW3FxMgmoOpGJl8KNPeqskrMjR+Ty0kWneMszvM6m2r /pSVXUBknVyeVnBBczRGUD6ZOG7PkfOMyJ5EEXxciemhIUgEaJ/+4pyURWeer8M73E1ETH mYf7/jYSqQEfRJS4ngdJnNXpdF1+hsU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1626352079; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CJEWq8qiVgvEoVbn4aLIKGb5fN74YYFkq1XScfceEpA=; b=rj2SYw+nY2a8p3YpBCTL+WirfJhVCko8/VO3xIclrvXosgaTLyoqdB0vgHgchJPJs+iwMT 20Earc0sUckerDAg== Received: from quack2.suse.cz (unknown [10.100.200.198]) by relay2.suse.de (Postfix) with ESMTP id ACA50A3B8D; Thu, 15 Jul 2021 12:27:58 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 86F2F1E0BF2; Thu, 15 Jul 2021 14:27:58 +0200 (CEST) Date: Thu, 15 Jul 2021 14:27:58 +0200 From: Jan Kara To: Greg Kroah-Hartman Cc: Naresh Kamboju , Holger Kiehl , Jan Kara , linux-kernel , Linus Torvalds , Andrew Morton , Guenter Roeck , Shuah Khan , patches@kernelci.org, lkft-triage@lists.linaro.org, Pavel Machek , Jon Hunter , Florian Fainelli , linux-stable , Paolo Valente , Jens Axboe Subject: Re: [PATCH 5.13 000/800] 5.13.2-rc1 review Message-ID: <20210715122758.GB31920@quack2.suse.cz> References: <20210712060912.995381202@linuxfoundation.org> <68b6051-09c-9dc8-4b52-c4e766fee5@praktifix.dwd.de> <50fb4713-6b5d-b5e0-786a-6ece57896d2f@praktifix.dwd.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 14-07-21 16:26:52, Greg Kroah-Hartman wrote: > On Wed, Jul 14, 2021 at 07:29:26PM +0530, Naresh Kamboju wrote: > > On Wed, 14 Jul 2021 at 19:22, Naresh Kamboju wrote: > > > > > > On Wed, 14 Jul 2021 at 19:01, Greg Kroah-Hartman > > > wrote: > > > > > > > > > > > > > My two cents, > > > While running ssuite long running stress testing we have noticed deadlock. > > > > > > > So if you drop that, all works well? I'll go drop that from the queues > > > > now. > > > > > > Let me drop that patch and test it again. > > > > > > Crash log, > > > > > > [ 1957.278399] ============================================ > > > [ 1957.283717] WARNING: possible recursive locking detected > > > [ 1957.289031] 5.13.2-rc1 #1 Not tainted > > > [ 1957.292703] -------------------------------------------- > > > [ 1957.298016] kworker/u8:7/236 is trying to acquire lock: > > > [ 1957.303241] ffff8cc203f92c38 (&bfqd->lock){-.-.}-{2:2}, at: > > > bfq_finish_requeue_request+0x55/0x500 [bfq] > > > [ 1957.312643] > > > [ 1957.312643] but task is already holding lock: > > > [ 1957.318467] ffff8cc203f92c38 (&bfqd->lock){-.-.}-{2:2}, at: > > > bfq_insert_requests+0x81/0x1750 [bfq] > > > [ 1957.327334] > > > [ 1957.327334] other info that might help us debug this: > > > [ 1957.333852] Possible unsafe locking scenario: > > > [ 1957.333852] > > > [ 1957.339762] CPU0 > > > [ 1957.342206] ---- > > > [ 1957.344651] lock(&bfqd->lock); > > > [ 1957.347873] lock(&bfqd->lock); > > > [ 1957.351097] > > > [ 1957.351097] *** DEADLOCK *** > > > [ 1957.351097] > > > > Also noticed on stable-rc 5.12.17-rc1. > > I dropped the same patch from there as well already, thanks. OK, when you dropped this patch, please also drop upstream commit fd2ef39cc9a6b ("blk: Fix lock inversion between ioc lock and bfqd lock"). Because without BFQ patch this block layer patch could cause some use-after-free issues. I'll have a look if I can understand why BFQ patch causes problems in stable kernels... Honza -- Jan Kara SUSE Labs, CR