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

Qu Wenruo
2024-11-30T04:28:07Z

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.