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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D61DDC636CC for ; Fri, 17 Feb 2023 01:45:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230139AbjBQBpE (ORCPT ); Thu, 16 Feb 2023 20:45:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229637AbjBQBpC (ORCPT ); Thu, 16 Feb 2023 20:45:02 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 812A33A85D; Thu, 16 Feb 2023 17:45:00 -0800 (PST) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4PHvhs5g6JzGpdn; Fri, 17 Feb 2023 09:43:09 +0800 (CST) Received: from [10.174.178.185] (10.174.178.185) by canpemm500010.china.huawei.com (7.192.105.118) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.6; Fri, 17 Feb 2023 09:44:58 +0800 Subject: Re: [PATCH v3 1/2] ext4: commit super block if fs record error when journal record without error To: Jan Kara , Ye Bin References: <20230214022905.765088-1-yebin@huaweicloud.com> <20230214022905.765088-2-yebin@huaweicloud.com> <20230216173159.zkj4qd2nmj2yjpkr@quack3> CC: , , , From: "yebin (H)" Message-ID: <63EEDC19.6010204@huawei.com> Date: Fri, 17 Feb 2023 09:44:57 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <20230216173159.zkj4qd2nmj2yjpkr@quack3> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.178.185] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/2/17 1:31, Jan Kara wrote: > On Tue 14-02-23 10:29:04, Ye Bin wrote: >> From: Ye Bin >> >> Now, 'es->s_state' maybe covered by recover journal. And journal errno >> maybe not recorded in journal sb as IO error. ext4_update_super() only >> update error information when 'sbi->s_add_error_count' large than zero. >> Then 'EXT4_ERROR_FS' flag maybe lost. >> To solve above issue commit error information after recover journal. >> >> Signed-off-by: Ye Bin >> --- >> fs/ext4/super.c | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/fs/ext4/super.c b/fs/ext4/super.c >> index dc3907dff13a..b94754ba8556 100644 >> --- a/fs/ext4/super.c >> +++ b/fs/ext4/super.c >> @@ -5932,6 +5932,18 @@ static int ext4_load_journal(struct super_block *sb, >> goto err_out; >> } >> >> + if (unlikely(es->s_error_count && !jbd2_journal_errno(journal) && >> + !(le16_to_cpu(es->s_state) & EXT4_ERROR_FS))) { >> + EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS; >> + es->s_state |= cpu_to_le16(EXT4_ERROR_FS); >> + err = ext4_commit_super(sb); >> + if (err) { >> + ext4_msg(sb, KERN_ERR, >> + "Failed to commit error information, please repair fs force!"); >> + goto err_out; >> + } >> + } >> + > Hum, I'm not sure I follow here. If journal replay has overwritten the > superblock (and thus the stored error info), then I'd expect > es->s_error_count got overwritten (possibly to 0) as well. And this is > actually relatively realistic scenario with errors=remount-ro behavior when > the first fs error happens. > > What I intended in my original suggestion was to save es->s_error_count, > es->s_state & EXT4_ERROR_FS, es->s_first_error_*, es->s_last_error_* before > doing journal replay in ext4_load_journal() and then after journal replay > merge this info back to the superblock Actually，commit 1c13d5c08728 ("ext4: Save error information to the superblock for analysis") already merged error info back to the superblock after journal replay except 'es->s_state'. The problem I have now is that the error flag in the journal superblock was not recorded, but the error message was recorded in the superblock. So it leads to ext4_clear_journal_err() does not detect errors and marks the file system as an error. Because ext4_update_super() is only set error flag when 'sbi->s_add_error_count > 0'. Although 'sbi->s_mount_state' is written to the super block when umount, but it is also conditional. So I handle the scenario "es->s_error_count && !jbd2_journal_errno(journal) && !(le16_to_cpu(es->s_state) & EXT4_ERROR_FS)". Maybe we can just store 'EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS' back to the superblock. But i prefer to mark fs as error if it contain detail error info without EXT4_ERROR_FS. > - if EXT4_ERROR_FS was set, set it > now as well, take max of old and new s_error_count, set s_first_error_* if > it is now unset, set s_last_error_* if stored timestamp is newer than > current timestamp. > > Or am I overengineering it now? :) > > Honza