ext4: fix super block checksum incorrect after mount

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@huawei.com>
Cc: stable@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220525012904.1604737-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b2ecae8..13d562d 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5302,14 +5302,6 @@ 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);
@@ -5367,6 +5359,14 @@ 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);