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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY 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 AAE65C169C4 for ; Fri, 1 Feb 2019 03:08:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80A1120870 for ; Fri, 1 Feb 2019 03:08:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726278AbfBADI5 (ORCPT ); Thu, 31 Jan 2019 22:08:57 -0500 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]:33667 "EHLO out30-44.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725854AbfBADI5 (ORCPT ); Thu, 31 Jan 2019 22:08:57 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01406;MF=xiaoguang.wang@linux.alibaba.com;NM=1;PH=DS;RN=2;SR=0;TI=SMTPD_---0TJMAqFw_1548990532; Received: from 30.7.9.25(mailfrom:xiaoguang.wang@linux.alibaba.com fp:SMTPD_---0TJMAqFw_1548990532) by smtp.aliyun-inc.com(127.0.0.1); Fri, 01 Feb 2019 11:08:53 +0800 Subject: Re: question about ext4 backup block group descriptors To: Andreas Dilger Cc: linux-ext4@vger.kernel.org References: <4fc3271a-3098-afcd-24c1-e2e130e1e86a@linux.alibaba.com> From: Xiaoguang Wang Message-ID: <806e62a9-07a1-0a29-05a3-65257f98a741@linux.alibaba.com> Date: Fri, 1 Feb 2019 11:08:52 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org hi, > On Jan 31, 2019, at 1:07 AM, Xiaoguang Wang wrote: >> >> Anyone can help answer when ext4's backup block group descriptors are updated? >> I had used blktrace to track the corresponding backup block group descriptor >> block, but didn't find that any backup blocks were written. >> Thanks in advance. > > The ext4 kernel code never updates the backup block group descriptors. That is only > done by e2fsck. I see, thanks very much. Regards, Xiaoguang Wang > > Cheers, Andreas > > > > >