Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning:
------------[ cut here ]------------
lockdep bfs error:-1
WARNING: kernel/locking/lockdep.c:2059 at print_bfs_bug+0x20/0x40 kernel/locking/lockdep.c:2059, CPU#1: syz.0.2754/31824
Modules linked in:
CPU: 1 UID: 0 PID: 31824 Comm: syz.0.2754 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:print_bfs_bug+0x22/0x40 kernel/locking/lockdep.c:2059
Code: 90 90 90 90 90 90 90 90 55 53 89 fb e8 f7 50 fd 02 89 c5 e8 d0 89 ff ff 85 ed 74 13 83 fb ff 74 16 48 8d 3d 40 73 eb 0d 89 de <67> 48 0f b9 3a 5b 5d e9 42 7f 7f 09 cc 48 c7 c7 72 e0 77 8d e8 05
RSP: 0018:ffffc9001fbb6f30 EFLAGS: 00010046
RAX: 000000000000003b RBX: 00000000ffffffff RCX: 195b5adf384d3400
RDX: ffffc90004bc9000 RSI: 00000000ffffffff RDI: ffffffff8f8c0d50
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52003f76d95 R12: ffffffff962e7628
R13: ffffffff93226fc8 R14: ffff888031f50000 R15: 000000000000021a
FS:  00007f22303be6c0(0000) GS:ffff888126279000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa6a1fbd000 CR3: 0000000029798000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 check_irq_usage kernel/locking/lockdep.c:-1 [inline]
 check_prev_add kernel/locking/lockdep.c:3169 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x2550/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
 class_raw_spinlock_constructor include/linux/spinlock.h:535 [inline]
 pcpu_alloc+0x25b/0x310 lib/debugobjects.c:273
 alloc_object+0xbf/0x300 lib/debugobjects.c:475
 lookup_object_or_alloc lib/debugobjects.c:702 [inline]
 debug_object_activate+0x153/0x520 lib/debugobjects.c:837
 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
 __call_rcu_common kernel/rcu/tree.c:3116 [inline]
 call_rcu+0x43/0x890 kernel/rcu/tree.c:3251
 xa_node_free lib/xarray.c:260 [inline]
 xas_delete_node lib/xarray.c:503 [inline]
 update_node lib/xarray.c:767 [inline]
 xas_store+0xe8c/0x1880 lib/xarray.c:852
 __xa_erase lib/xarray.c:1649 [inline]
 xa_erase+0x6a/0xf0 lib/xarray.c:1670
 btrfs_delete_ref_head+0x141/0x2c0 fs/btrfs/delayed-ref.c:570
 check_ref_cleanup+0x203/0x3c0 fs/btrfs/extent-tree.c:3595
 btrfs_free_tree_block+0x478/0xc60 fs/btrfs/extent-tree.c:3658
 promote_child_to_root fs/btrfs/ctree.c:903 [inline]
 balance_level+0x8da/0x2b60 fs/btrfs/ctree.c:956
 setup_nodes_for_search fs/btrfs/ctree.c:1654 [inline]
 btrfs_search_slot+0x138a/0x2d30 fs/btrfs/ctree.c:2165
 btrfs_del_orphan_item+0xd9/0x1f0 fs/btrfs/orphan.c:41
 btrfs_orphan_del fs/btrfs/inode.c:3703 [inline]
 btrfs_evict_inode+0xb49/0xe80 fs/btrfs/inode.c:5734
 evict+0x61e/0xb10 fs/inode.c:841
 filename_unlinkat+0x445/0x610 fs/namei.c:5572
 __do_sys_unlinkat fs/namei.c:5597 [inline]
 __se_sys_unlinkat+0x83/0x1a0 fs/namei.c:5589
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f223216cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f22303be028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007f22323e5fa0 RCX: 00007f223216cdd9
RDX: 0000000000000000 RSI: 0000200000000180 RDI: ffffffffffffff9c
RBP: 00007f2232202d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f22323e6038 R14: 00007f22323e5fa0 R15: 00007ffea9979448
 </TASK>
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	90                   	nop
   2:	90                   	nop
   3:	90                   	nop
   4:	90                   	nop
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	55                   	push   %rbp
   9:	53                   	push   %rbx
   a:	89 fb                	mov    %edi,%ebx
   c:	e8 f7 50 fd 02       	call   0x2fd5108
  11:	89 c5                	mov    %eax,%ebp
  13:	e8 d0 89 ff ff       	call   0xffff89e8
  18:	85 ed                	test   %ebp,%ebp
  1a:	74 13                	je     0x2f
  1c:	83 fb ff             	cmp    $0xffffffff,%ebx
  1f:	74 16                	je     0x37
  21:	48 8d 3d 40 73 eb 0d 	lea    0xdeb7340(%rip),%rdi        # 0xdeb7368
  28:	89 de                	mov    %ebx,%esi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	5b                   	pop    %rbx
  30:	5d                   	pop    %rbp
  31:	e9 42 7f 7f 09       	jmp    0x97f7f78
  36:	cc                   	int3
  37:	48 c7 c7 72 e0 77 8d 	mov    $0xffffffff8d77e072,%rdi
  3e:	e8                   	.byte 0xe8
  3f:	05                   	.byte 0x5