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 43C8EC433F5 for ; Mon, 21 Mar 2022 13:35:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347966AbiCUNgz (ORCPT ); Mon, 21 Mar 2022 09:36:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235400AbiCUNgb (ORCPT ); Mon, 21 Mar 2022 09:36:31 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E2294474B; Mon, 21 Mar 2022 06:35:05 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4KMbDB4F2FzfZMc; Mon, 21 Mar 2022 21:33:30 +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 15.1.2308.21; Mon, 21 Mar 2022 21:35:02 +0800 Subject: Re: [PATCH -next] ext4: Fix symlink file size not match to file content To: Jan Kara References: <20220321113408.4112428-1-yebin10@huawei.com> <20220321113703.cibgeac5ipslg3df@quack3.lan> CC: , , , , From: yebin Message-ID: <62387F05.2090408@huawei.com> Date: Mon, 21 Mar 2022 21:35:01 +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: <20220321113703.cibgeac5ipslg3df@quack3.lan> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.185] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) 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 2022/3/21 19:37, Jan Kara wrote: > On Mon 21-03-22 19:34:08, Ye Bin wrote: >> We got issue as follows: >> [home]# fsck.ext4 -fn ram0yb >> e2fsck 1.45.6 (20-Mar-2020) >> Pass 1: Checking inodes, blocks, and sizes >> Pass 2: Checking directory structure >> Symlink /p3/d14/d1a/l3d (inode #3494) is invalid. >> Clear? no >> Entry 'l3d' in /p3/d14/d1a (3383) has an incorrect filetype (was 7, should be 0). >> Fix? no >> >> As symlink file size not match to file content. If symlink data block >> writback failed, will call ext4_finish_bio to end io. In this path don't >> mark buffer error. When umount do checkpoint can't detect buffer error, >> then will cleanup jounral. Actually, correct data maybe in journal area. >> To solve this issue, mark buffer error when detect bio error in >> ext4_finish_bio. > Thanks for the patch! Let me rephrase the text a bit: > > As the symlink file size does not match the file content. If the writeback > of the symlink data block failed, ext4_finish_bio() handles the end of IO. > However this function fails to mark the buffer with BH_write_io_error and > so when unmount does journal checkpoint it cannot detect the writeback > error and will cleanup the journal. Thus we've lost the correct data in the > journal area. To solve this issue, mark the buffer as BH_write_io_error in > ext4_finish_bio(). > >> Signed-off-by: Ye Bin >> --- >> fs/ext4/page-io.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c >> index 495ce59fb4ad..14695e2b5042 100644 >> --- a/fs/ext4/page-io.c >> +++ b/fs/ext4/page-io.c >> @@ -134,8 +134,10 @@ static void ext4_finish_bio(struct bio *bio) >> continue; >> } >> clear_buffer_async_write(bh); >> - if (bio->bi_status) >> + if (bio->bi_status) { >> + set_buffer_write_io_error(bh); > Why don't you use mark_buffer_write_io_error()? It will also update other IO > error counters properly so that e.g. fsync(2) or sync_filesystem() can properly > report IO error etc. Granted we'll abort the journal in response to > checkpointing error so the failure will be hard to miss anyway but still > :). > > Honza 'ext4_finish_bio' already call 'mapping_set_error' set mapping error , I think fsync and sync_filesystem can report IO error. static inline void mapping_set_error(struct address_space *mapping, int error) { if (likely(!error)) return; /* Record in wb_err for checkers using errseq_t based tracking */ __filemap_set_wb_err(mapping, error); /* Record it in superblock */ if (mapping->host) errseq_set(&mapping->host->i_sb->s_wb_err, error); /* Record it in flags for now, for legacy callers */ if (error == -ENOSPC) set_bit(AS_ENOSPC, &mapping->flags); else set_bit(AS_EIO, &mapping->flags); }