linux-kernel - [PATCH 5.18 127/141] ext4: fix super block checksum incorrect after mount

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Date:   Mon, 20 Jun 2022 14:51:05 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Ye Bin <yebin10@...wei.com>,
        stable@...nel.org, Jan Kara <jack@...e.cz>,
        Ritesh Harjani <ritesh.list@...il.com>,
        Theodore Tso <tytso@....edu>
Subject: [PATCH 5.18 127/141] ext4: fix super block checksum incorrect after mount

From: Ye Bin <yebin10@...wei.com>

commit 9b6641dd95a0c441b277dd72ba22fed8d61f76ad upstream.

We got issue as follows:
[home]# mount  /dev/sda  test
EXT4-fs (sda): warning: mounting fs with errors, running e2fsck is recommended
[home]# dmesg
EXT4-fs (sda): warning: mounting fs with errors, running e2fsck is recommended
EXT4-fs (sda): Errors on filesystem, clearing orphan list.
EXT4-fs (sda): recovery complete
EXT4-fs (sda): mounted filesystem with ordered data mode. Quota mode: none.
[home]# debugfs /dev/sda
debugfs 1.46.5 (30-Dec-2021)
Checksum errors in superblock!  Retrying...

Reason is ext4_orphan_cleanup will reset ‘s_last_orphan’ but not update
super block checksum.

To solve above issue, defer update super block checksum after
ext4_orphan_cleanup.

Signed-off-by: Ye Bin <yebin10@...wei.com>
Cc: stable@...nel.org
Reviewed-by: Jan Kara <jack@...e.cz>
Reviewed-by: Ritesh Harjani <ritesh.list@...il.com>
Link: https://lore.kernel.org/r/20220525012904.1604737-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@....edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 fs/ext4/super.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5422,14 +5422,6 @@ no_journal:
 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
 					  GFP_KERNEL);
 	}
-	/*
-	 * Update the checksum after updating free space/inode
-	 * counters.  Otherwise the superblock can have an incorrect
-	 * checksum in the buffer cache until it is written out and
-	 * e2fsprogs programs trying to open a file system immediately
-	 * after it is mounted can fail.
-	 */
-	ext4_superblock_csum_set(sb);
 	if (!err)
 		err = percpu_counter_init(&sbi->s_dirs_counter,
 					  ext4_count_dirs(sb), GFP_KERNEL);
@@ -5487,6 +5479,14 @@ no_journal:
 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
 	ext4_orphan_cleanup(sb, es);
 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
+	/*
+	 * Update the checksum after updating free space/inode counters and
+	 * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
+	 * checksum in the buffer cache until it is written out and
+	 * e2fsprogs programs trying to open a file system immediately
+	 * after it is mounted can fail.
+	 */
+	ext4_superblock_csum_set(sb);
 	if (needs_recovery) {
 		ext4_msg(sb, KERN_INFO, "recovery complete");
 		err = ext4_mark_recovery_complete(sb, es);