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 3A8D0C433EF for ; Thu, 23 Dec 2021 01:41:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242511AbhLWBlg (ORCPT ); Wed, 22 Dec 2021 20:41:36 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:33899 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235957AbhLWBld (ORCPT ); Wed, 22 Dec 2021 20:41:33 -0500 Received: from canpemm500010.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4JKCZr16QZzcc8V; Thu, 23 Dec 2021 09:41:08 +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 15.1.2308.20; Thu, 23 Dec 2021 09:41:31 +0800 Subject: Re: [PATCH -next] ext4: Fix remount with 'abort' option isn't effective To: Lukas Czerner References: <20211221123214.2410593-1-yebin10@huawei.com> <20211221144305.nlryh7q2cgdbpmi5@work> <61C27A0E.9050900@huawei.com> <20211222091947.chmg6mcetocrmygd@work> CC: , , , , From: yebin Message-ID: <61C3D3CB.1010106@huawei.com> Date: Thu, 23 Dec 2021 09:41:31 +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: <20211222091947.chmg6mcetocrmygd@work> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit 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 2021/12/22 17:19, Lukas Czerner wrote: > On Wed, Dec 22, 2021 at 09:06:22AM +0800, yebin wrote: >> >> On 2021/12/21 22:43, Lukas Czerner wrote: >>> Hi, >>> >>> nice catch. This is a bug indeed. However I am currently in a process of >>> changing the ctx_set/clear/test_ helpers because currently it generates >>> functions that are unused. >>> >>> While I am at it I can just create a custom ctx_set_mount_flags() >>> helper that would behave as expected so that we won't have to specify >>> "1 < EXT4_MF_FS_ABORTED" which is not really obvious and hence error >>> prone. >> Actually, I fixed the first version as follows: > Allright, this looks better. > >> diff --git a/fs/ext4/super.c b/fs/ext4/super.c >> index b72d989b77fb..199920ffc7d3 100644 >> --- a/fs/ext4/super.c >> +++ b/fs/ext4/super.c >> @@ -2049,8 +2049,8 @@ struct ext4_fs_context { >> unsigned int mask_s_mount_opt; >> unsigned int vals_s_mount_opt2; >> unsigned int mask_s_mount_opt2; >> - unsigned int vals_s_mount_flags; >> - unsigned int mask_s_mount_flags; >> + unsigned long vals_s_mount_flags; >> + unsigned long mask_s_mount_flags; >> unsigned int opt_flags; /* MOPT flags */ >> unsigned int spec; >> u32 s_max_batch_time; >> @@ -2166,7 +2166,12 @@ static inline bool ctx_test_##name(struct ext4_fs_context *ctx, int flag)\ >> EXT4_SET_CTX(flags); >> EXT4_SET_CTX(mount_opt); >> EXT4_SET_CTX(mount_opt2); >> -EXT4_SET_CTX(mount_flags); >> + >> +static inline void ctx_set_mount_flags(struct ext4_fs_context *ctx, int bit) > Maybe ctx_set_mount_flag since you can't really set more than one this > way? So I think it's a little inappropriate to use the current repair scheme. >> +{ >> + set_bit(bit, &ctx->mask_s_mount_flags); >> + set_bit(bit, &ctx->vals_s_mount_flags); >> +} >> >> >> I think 'mask_s_mount_flags' is useless now. > So how would we know what flags have changed ? Sure, there is currently > no need to clear the flag but that can come in future and once it does > we'll only need to create a clear helper, the rest will be ready. > I'd rather keep it. > > -Lukas From this point of view, I agree with you. >>> My plan is to send my patch set including this one tomorrow, will that >>> be fine with you ? >>> >>> -Lukas >>> >>> On Tue, Dec 21, 2021 at 08:32:14PM +0800, Ye Bin wrote: >>>> We test remount with 'abort' option as follows: >>>> [root@localhost home]# mount /dev/sda test >>>> [root@localhost home]# mount | grep test >>>> /dev/sda on /home/test type ext4 (rw,relatime) >>>> [root@localhost home]# mount -o remount,abort test >>>> [root@localhost home]# mount | grep test >>>> /dev/sda on /home/test type ext4 (rw,relatime) >>>> >>>> Obviously, remount 'abort' option isn't effective. >>>> After 6e47a3cc68fc commit we process abort option with 'ctx_set_mount_flags': >>>> static inline void ctx_set_mount_flags(struct ext4_fs_context *ctx, int flag) >>>> { >>>> ctx->mask_s_mount_flags |= flag; >>>> ctx->vals_s_mount_flags |= flag; >>>> } >>>> >>>> But we test 'abort' option with 'ext4_test_mount_flag': >>>> static inline int ext4_test_mount_flag(struct super_block *sb, int bit) >>>> { >>>> return test_bit(bit, &EXT4_SB(sb)->s_mount_flags); >>>> } >>>> >>>> To solve this issue, pass (1 << EXT4_MF_FS_ABORTED) to 'ctx_set_mount_flags'. >>>> >>>> Fixes:6e47a3cc68fc("ext4: get rid of super block and sbi from handle_mount_ops()") >>>> Signed-off-by: Ye Bin >>>> --- >>>> fs/ext4/super.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/fs/ext4/super.c b/fs/ext4/super.c >>>> index b72d989b77fb..071b7b3c5678 100644 >>>> --- a/fs/ext4/super.c >>>> +++ b/fs/ext4/super.c >>>> @@ -2236,7 +2236,7 @@ static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param) >>>> param->key); >>>> return 0; >>>> case Opt_abort: >>>> - ctx_set_mount_flags(ctx, EXT4_MF_FS_ABORTED); >>>> + ctx_set_mount_flags(ctx, 1 << EXT4_MF_FS_ABORTED); >>>> return 0; >>>> case Opt_i_version: >>>> ctx_set_flags(ctx, SB_I_VERSION); >>>> -- >>>> 2.31.1 >>>> >>> . >>> > . >