From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0EA25611E for ; Tue, 28 Oct 2025 06:47:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761634054; cv=none; b=MycHR09lt6JwtjOYjebR75i6FFsMmZwzgumlU1vt2Q8fE6K5RhMPuQ8g7ULDaVmLR79PCC3ADYpb2lCjViLbPWwGQWgj/AE4NJnO+4W9Kpn4zqHTCW3lD2jSkmZ6rfuqyqNDbdqbLG2IZi50G+2a8s8UcmZM6nGAgdmuTTK1+3c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761634054; c=relaxed/simple; bh=S5TIjBBjg8/YqikqWS1dMZRuPknKoKl8XDcsT4mTIDc=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=l2fYbEMmiL/ph8Vbrag9u7ck8kjuzLqUohvjhSodH8nvoOISb6cPy5J8uqUEDhAV1bZYcvWWoUmgu6LHsDQepihjYuhHzRuxRbubw+evMJc/Zm1al+ZvN7Ux0Ti00CHxc6aEFhoBwarZiWvkQnKGgWGCIstbAdZsKCuxxwNuZjk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4cwgsp3kV3zYQtx6 for ; Tue, 28 Oct 2025 14:47:26 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.75]) by mail.maildlp.com (Postfix) with ESMTP id 857911A1544 for ; Tue, 28 Oct 2025 14:47:29 +0800 (CST) Received: from huaweicloud.com (unknown [10.50.87.132]) by APP2 (Coremail) with SMTP id Syh0CgCH3UUAZwBp50aBBw--.11831S4; Tue, 28 Oct 2025 14:47:29 +0800 (CST) From: Ye Bin To: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org Cc: jack@suse.cz Subject: [PATCH] jbd2: fix the inconsistency between checksum and data in memory for journal sb Date: Tue, 28 Oct 2025 14:47:28 +0800 Message-Id: <20251028064728.91827-1-yebin@huaweicloud.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:Syh0CgCH3UUAZwBp50aBBw--.11831S4 X-Coremail-Antispam: 1UD129KBjvJXoWxCrykJw15WFy8trWxuFW3Jrb_yoW5GF48pr y5CF98Zr9YvryUAw18KF4rJayrXry0yayUKr4q9FZ2kay5Jw12v34DtFn8CFWqqFWjga4x JF1UG39rGw12vaUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUgCb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x 0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCj c4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4 CE17CEb7AF67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1x MIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF 4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsG vfC2KfnxnUUI43ZEXa7IU1CPfJUUUUU== X-CM-SenderInfo: p1hex046kxt4xhlfz01xgou0bp/ From: Ye Bin Copying the file system while it is mounted as read-only results in a mount failure: [~]# mkfs.ext4 -F /dev/sdc [~]# mount /dev/sdc -o ro /mnt/test [~]# dd if=/dev/sdc of=/dev/sda bs=1M [~]# mount /dev/sda /mnt/test1 [ 1094.849826] JBD2: journal checksum error [ 1094.850927] EXT4-fs (sda): Could not load journal inode mount: mount /dev/sda on /mnt/test1 failed: Bad message Above issue may happen as follows: ext4_fill_super set_journal_csum_feature_set(sb) if (ext4_has_metadata_csum(sb)) incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3; if (test_opt(sb, JOURNAL_CHECKSUM) jbd2_journal_set_features(sbi->s_journal, compat, 0, incompat); lock_buffer(journal->j_sb_buffer); sb->s_feature_incompat |= cpu_to_be32(incompat); //The data in the journal sb was modified, but the checksum was not updated, so the data remaining in memory has a mismatch between the data and the checksum. unlock_buffer(journal->j_sb_buffer); In this case, the journal sb copied over is in a state where the checksum and data are inconsistent, so mounting fails. To solve the above issue, update the checksum in memory after modifying the journal sb. Fixes: 4fd5ea43bc11 ("jbd2: checksum journal superblock") Signed-off-by: Ye Bin --- fs/jbd2/journal.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index d480b94117cd..5b6e8c1a5e6a 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -2349,6 +2349,8 @@ int jbd2_journal_set_features(journal_t *journal, unsigned long compat, sb->s_feature_compat |= cpu_to_be32(compat); sb->s_feature_ro_compat |= cpu_to_be32(ro); sb->s_feature_incompat |= cpu_to_be32(incompat); + if (jbd2_journal_has_csum_v2or3(journal)) + sb->s_checksum = jbd2_superblock_csum(sb); unlock_buffer(journal->j_sb_buffer); jbd2_journal_init_transaction_limits(journal); @@ -2378,9 +2380,13 @@ void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, sb = journal->j_superblock; + lock_buffer(journal->j_sb_buffer); sb->s_feature_compat &= ~cpu_to_be32(compat); sb->s_feature_ro_compat &= ~cpu_to_be32(ro); sb->s_feature_incompat &= ~cpu_to_be32(incompat); + if (jbd2_journal_has_csum_v2or3(journal)) + sb->s_checksum = jbd2_superblock_csum(sb); + unlock_buffer(journal->j_sb_buffer); jbd2_journal_init_transaction_limits(journal); } EXPORT_SYMBOL(jbd2_journal_clear_features); -- 2.34.1