Re: [syzbot] [btrfs?] kernel BUG in __folio_start_writeback

[Qu Wenruo <wqu@suse.com>]

在 2024/11/30 12:21, syzbot 写道:
> Hello,
> 
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> BUG: MAX_LOCKDEP_KEYS too low!
> 
> BUG: MAX_LOCKDEP_KEYS too low!

Hi Syzbot guys,

Syzbot is great, but I'm wondering if it's possible to disable lockdep 
for this particular test?
Or just let it re-run the test again?

If the test doesn't crash with my fix, but only lockdep warnings on 
certain too low values, I'd call it fixed.

BTW, I'm not seeing where I can changed the MAX_LCKDEP_KEYS values in 
the kernel...

Thanks,
Qu

> turning off the locking correctness validator.
> CPU: 1 UID: 0 PID: 11728 Comm: kworker/u8:10 Not tainted 6.12.0-rc7-syzkaller-00133-g17a4e91a431b #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
> Workqueue: btrfs-cache btrfs_work_helper
> Call Trace:
>   <TASK>
>   __dump_stack lib/dump_stack.c:94 [inline]
>   dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
>   register_lock_class+0x827/0x980 kernel/locking/lockdep.c:1328
>   __lock_acquire+0xf3/0x2100 kernel/locking/lockdep.c:5077
>   lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
>   process_one_work kernel/workqueue.c:3204 [inline]
>   process_scheduled_works+0x950/0x1850 kernel/workqueue.c:3310
>   worker_thread+0x870/0xd30 kernel/workqueue.c:3391
>   kthread+0x2f0/0x390 kernel/kthread.c:389
>   ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
>   ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>   </TASK>
> 
> 
> Tested on:
> 
> commit:         17a4e91a btrfs: test if we need to wait the writeback ..
> git tree:       https://github.com/adam900710/linux.git writeback_fix
> console output: https://syzkaller.appspot.com/x/log.txt?x=12c5ad30580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=fa4954ad2c62b915
> dashboard link: https://syzkaller.appspot.com/bug?extid=aac7bff85be224de5156
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> 
> Note: no patches were applied.