From nobody Mon Apr 13 20:05:40 2026 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 06362C433FE for ; Wed, 16 Nov 2022 07:07:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232721AbiKPHG5 (ORCPT ); Wed, 16 Nov 2022 02:06:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232426AbiKPHGr (ORCPT ); Wed, 16 Nov 2022 02:06:47 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 685F914088; Tue, 15 Nov 2022 23:06:46 -0800 (PST) Received: from dggpeml500021.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4NBvGh5strzRpPH; Wed, 16 Nov 2022 15:06:20 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggpeml500021.china.huawei.com (7.185.36.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 16 Nov 2022 15:06:39 +0800 From: Baokun Li To: CC: , , , , , , , Subject: [PATCH v2 3/3] ext4: fix corruption when online resizing a 1K bigalloc fs Date: Wed, 16 Nov 2022 15:28:02 +0800 Message-ID: <20221116072802.526990-4-libaokun1@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20221116072802.526990-1-libaokun1@huawei.com> References: <20221116072802.526990-1-libaokun1@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpeml500021.china.huawei.com (7.185.36.21) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When a backup superblock is updated in update_backups(), the primary superblock's offset in the group (that is, sbi->s_sbh->b_blocknr) is used as the backup superblock's offset in its group. However, when the block size is 1K and bigalloc is enabled, the two offsets are not equal. This causes the backup group descriptors to be overwritten by the superblock in update_backups(). Moreover, if meta_bg is enabled, the file system will be corrupted because this feature uses backup group descriptors. To solve this issue, we use a more accurate ext4_group_first_block_no() as the offset of the backup superblock in its group. Fixes: d77147ff443b ("ext4: add support for online resizing with bigalloc") Signed-off-by: Baokun Li Reviewed-by: Jan Kara --- V1->V2: Replace s_first_data_block with ext4_group_first_block_no() to avoid type warning.(Reported-by: kernel test robot ) fs/ext4/resize.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 32fbfc173571..98e544c2f97d 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1591,8 +1591,8 @@ static int ext4_flex_group_add(struct super_block *sb, int meta_bg =3D ext4_has_feature_meta_bg(sb); sector_t old_gdb =3D 0; =20 - update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, - sizeof(struct ext4_super_block), 0); + update_backups(sb, ext4_group_first_block_no(sb, 0), + (char *)es, sizeof(struct ext4_super_block), 0); for (; gdb_num <=3D gdb_num_end; gdb_num++) { struct buffer_head *gdb_bh; =20 @@ -1803,7 +1803,7 @@ static int ext4_group_extend_no_check(struct super_bl= ock *sb, if (test_opt(sb, DEBUG)) printk(KERN_DEBUG "EXT4-fs: extended group to %llu " "blocks\n", ext4_blocks_count(es)); - update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, + update_backups(sb, ext4_group_first_block_no(sb, 0), (char *)es, sizeof(struct ext4_super_block), 0); } return err; --=20 2.31.1