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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 07D0FC63777 for ; Thu, 3 Dec 2020 06:57:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFE4E20758 for ; Thu, 3 Dec 2020 06:57:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729843AbgLCG5b (ORCPT ); Thu, 3 Dec 2020 01:57:31 -0500 Received: from mx2.suse.de ([195.135.220.15]:52118 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbgLCG5b (ORCPT ); Thu, 3 Dec 2020 01:57:31 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 6A023ABE9; Thu, 3 Dec 2020 06:56:49 +0000 (UTC) To: Yi Li Cc: Yi Li , kent.overstreet@gmail.com, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, Guo Chao References: <20201130112137.587437-1-yili@winhong.com> From: Coly Li Subject: Re: [PATCH] bcache: fix panic due to cache_set is null Message-ID: <79fde596-254a-510c-547a-b1525985de9d@suse.de> Date: Thu, 3 Dec 2020 14:56:45 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/3/20 2:25 PM, Yi Li wrote: >> On 12/1/20 12:35 PM, Yi Li wrote: >>> sorry, This patch will cause deadlock, i will check and redo it. >> >> Can you try latest upstream kernel firstly ? Before spending more time >> on the fix. >> > > This issue just happened three times （xenserver7.5 dom0 kernel） on the > same machine and cannot reproduce it now. and have not reproduce it > using the lastest uptream kernel. > Hmm, this is something very probably that I am not able to help. It seems the kernel is a third-part maintained Linux v4.4 based kernel + bcache backport, which is out of my view. If similar problem happens on latest upstream kernel, or at least v5.8+ kernel, I can help to take a look. >> If I remember correctly, when cancel_writeback_rate_update_dwork() is >> not timed out, the cache set memory won't be freed before the >> writeback_rate_update worker terminates. It is possible that I miss >> something in the code, but I suggest to test with a kernel after v5.3, >> and better a v5.8+ kernel. >> >> Coly Li >> > Thanks. > > it is confused that why writeback_rate_update worker run again after > cancel_delayed_work_sync( kernel log telled). > [snipped] Coly Li