Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning: ------------[ cut here ]------------ lockdep bfs error:-1 WARNING: kernel/locking/lockdep.c:2103 at print_bfs_bug+0x20/0x40 kernel/locking/lockdep.c:2103, CPU#1: syz.1.1338/20920 Modules linked in: CPU: 1 UID: 0 PID: 20920 Comm: syz.1.1338 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:print_bfs_bug+0x22/0x40 kernel/locking/lockdep.c:2103 Code: 90 90 90 90 90 90 90 90 55 53 89 fb e8 97 51 28 03 89 c5 e8 e0 85 ff ff 85 ed 74 13 83 fb ff 74 16 48 8d 3d 50 d2 12 0e 89 de <67> 48 0f b9 3a 5b 5d c3 cc cc cc cc cc 48 c7 c7 29 7d 9f 8d e8 a5 RSP: 0018:ffffc90013bdf1f0 EFLAGS: 00010046 RAX: 000000000000003b RBX: 00000000ffffffff RCX: 352c9465cfb12c00 RDX: ffffc90006c22000 RSI: 00000000ffffffff RDI: ffffffff8fb53c30 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff5200277bded R12: 0000000000000038 R13: ffffffff9357e280 R14: ffffffff965dd478 R15: ffffffff965de7b8 FS: 00007fc36eaa66c0(0000) GS:ffff888125cc2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555e4004e8 CR3: 0000000033fec000 CR4: 00000000003526f0 Call Trace: check_irq_usage kernel/locking/lockdep.c:-1 [inline] check_prev_add kernel/locking/lockdep.c:3213 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x25ed/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 do_write_seqcount_begin_nested include/linux/seqlock.h:478 [inline] do_write_seqcount_begin include/linux/seqlock.h:504 [inline] psi_write_begin+0xa9/0x160 kernel/sched/psi.c:183 psi_account_irqtime+0x1dd/0x6d0 kernel/sched/psi.c:1030 __schedule+0x971/0x5700 kernel/sched/core.c:7277 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7606 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x920 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5947 Code: ff ff ff e8 d0 19 b7 09 f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 12 d4 03 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 07 2a 13 RSP: 0018:ffffc90013bdf788 EFLAGS: 00000286 RAX: 352c9465cfb12c00 RBX: 0000000000000001 RCX: 0000000000000046 RDX: ffff888036ec6a00 RSI: ffffffff8dae12cb RDI: ffffffff8bcc4c80 RBP: ffff888036ec5dc0 R08: 0000000000000008 R09: ffffffff95e84720 R10: 00000000dca45fca R11: 000000005575b93c R12: ffff888035c8e938 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000246 touch_wq_lockdep_map+0xcb/0x180 kernel/workqueue.c:4111 __flush_workqueue+0x148/0x1470 kernel/workqueue.c:4153 drain_workqueue+0xce/0x380 kernel/workqueue.c:4317 destroy_workqueue+0xbb/0xc60 kernel/workqueue.c:6155 btrfs_stop_all_workers+0x49/0x280 fs/btrfs/disk-io.c:1764 open_ctree+0x14f8/0x4190 fs/btrfs/disk-io.c:3825 btrfs_fill_super fs/btrfs/super.c:974 [inline] btrfs_get_tree_super fs/btrfs/super.c:1969 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2112 [inline] btrfs_get_tree+0x1084/0x1980 fs/btrfs/super.c:2146 vfs_get_tree+0x92/0x2a0 fs/super.c:1932 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3772 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3848 do_mount fs/namespace.c:4181 [inline] __do_sys_mount fs/namespace.c:4397 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4374 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc37084f40a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007fc36eaa5e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc36eaa5ee0 RCX: 00007fc37084f40a RDX: 0000200000005100 RSI: 0000200000000040 RDI: 00007fc36eaa5ea0 RBP: 0000200000005100 R08: 00007fc36eaa5ee0 R09: 0000000000800810 R10: 0000000000800810 R11: 0000000000000246 R12: 0000200000000040 R13: 00007fc36eaa5ea0 R14: 000000000000510a R15: 0000200000000140 ---------------- 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 97 51 28 03 call 0x32851a8 11: 89 c5 mov %eax,%ebp 13: e8 e0 85 ff ff call 0xffff85f8 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 50 d2 12 0e lea 0xe12d250(%rip),%rdi # 0xe12d278 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: c3 ret 32: cc int3 33: cc int3 34: cc int3 35: cc int3 36: cc int3 37: 48 c7 c7 29 7d 9f 8d mov $0xffffffff8d9f7d29,%rdi 3e: e8 .byte 0xe8 3f: a5 movsl %ds:(%rsi),%es:(%rdi)