ext4: fix super block checksum incorrect after mount

mainline inclusion
from mainline-v5.19-rc3
commit 9b6641dd
category: bugfix
bugzilla: 186927, https://gitee.com/src-openeuler/kernel/issues/I5YIY6
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9b6641dd95a0c441b277dd72ba22fed8d61f76ad

--------------------------------

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: NYe Bin <yebin10@huawei.com>
Cc: stable@kernel.org
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NRitesh Harjani <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220525012904.1604737-1-yebin10@huawei.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NBaokun Li <libaokun1@huawei.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/ext4/super.c

@@ -5078,14 +5078,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		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);
@@ -5140,6 +5132,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	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);