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

syzbot
2024-11-30T01:51:04Z

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!
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.