How to fix the bug in "WARNING: kobject bug in erofs_unregister_sysfs"?

[Dongliang Mu]

Hi kernel developers,

I am writing to kindly ask for some suggestions on fixing "WARNING:
kobject bug in erofs_unregister_sysfs".

The underlying issue is in the following,

erofs_fc_get_tree
-> get_tree_bdev
  -> fill_super
    -> erofs_fc_fill_super

When erofs_register_sysfs fails in the calling kobject_init_and_add,
it just returned an error code and the parent function will call
deactivate_locked_super to do clean up.

In the following stack trace, it finally calls erofs_unregister_sysfs
without knowing the execution status of erofs_register_sysfs, which
leads to the kobject bug.

 erofs_unregister_sysfs+0x46/0x60 fs/erofs/sysfs.c:225
 erofs_put_super+0x37/0xb0 fs/erofs/super.c:771
 generic_shutdown_super+0x14c/0x400 fs/super.c:465
 kill_block_super+0x97/0xf0 fs/super.c:1397
 erofs_kill_sb+0x60/0x190 fs/erofs/super.c:752
 deactivate_locked_super+0x94/0x160 fs/super.c:335
 get_tree_bdev+0x573/0x760 fs/super.c:1297

I am not sure how to fix this bug. Any suggestion is appreciated.

--
My best regards to you.

     No System Is Safe!
     Dongliang Mu