ceph: No mds server is up or the cluster is laggy
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-executor.2/12906
Modules linked in:
CPU: 1 UID: 0 PID: 12906 Comm: syz-executor.2 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 e7 32 fd 02 89 c5 e8 d0 89 ff ff 85 ed 74 13 83 fb ff 74 16 48 8d 3d c0 61 eb 0d 89 de <67> 48 0f b9 3a 5b 5d e9 02 0f 7f 09 cc 48 c7 c7 f1 c2 77 8d e8 c5
RSP: 0018:ffffc90003cc7358 EFLAGS: 00010046
RAX: 000000000000003b RBX: 00000000ffffffff RCX: fd0834e1d0c46000
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8f8bfc10
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1017124923 R12: ffffffff95fdcae8
R13: ffffffff931706c0 R14: ffff888053868000 R15: 0000000000000066
FS:  00007fb473c5e6c0(0000) GS:ffff88812627d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb47490f7d0 CR3: 000000002a194000 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
 do_write_seqcount_begin_nested include/linux/seqlock.h:478 [inline]
 do_write_seqcount_begin include/linux/seqlock.h:504 [inline]
 psi_write_begin+0xab/0x160 kernel/sched/psi.c:183
 psi_account_irqtime+0x1e2/0x6f0 kernel/sched/psi.c:1030
 __schedule+0x964/0x54c0 kernel/sched/core.c:7181
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x14f/0x730 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 81 a5 7b 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 5b f0 c9 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 80 69 7f 09 cc 48 8d 3d 38 b6 eb
RSP: 0018:ffffc90003cc7928 EFLAGS: 00000286
RAX: fd0834e1d0c46000 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 0000000000000002 RSI: ffffffff8d8609ab RDI: ffffffff8ba74b60
RBP: ffffffff818d6095 R08: 0000000000000008 R09: ffffffff959ab3a0
R10: 0000000009c23502 R11: 0000000065a4979a R12: 0000000000000000
R13: ffff88805202b938 R14: 0000000000000001 R15: 0000000000000246
 touch_wq_lockdep_map+0xcb/0x180 kernel/workqueue.c:4017
 __flush_workqueue+0x14b/0x14f0 kernel/workqueue.c:4059
 flush_fs_workqueues fs/ceph/super.c:882 [inline]
 ceph_kill_sb+0x128/0x9c0 fs/ceph/super.c:1545
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 ceph_get_tree+0x9e7/0x19e0 fs/ceph/super.c:1370
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 vfs_cmd_create+0xa2/0x200 fs/fsopen.c:231
 __do_sys_fsconfig fs/fsopen.c:463 [inline]
 __se_sys_fsconfig+0x6cf/0x820 fs/fsopen.c:350
 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: 0033:0x7fb4748ce3b9
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 d0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb473c5e078 EFLAGS: 00000246 ORIG_RAX: 00000000000001af
RAX: ffffffffffffffda RBX: 00007fb474a0bf80 RCX: 00007fb4748ce3b9
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003
RBP: 00007fb47492f498 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fb474a0bf80 R15: 00007ffca85a1098
 </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 e7 32 fd 02       	call   0x2fd32f8
  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 c0 61 eb 0d 	lea    0xdeb61c0(%rip),%rdi        # 0xdeb61e8
  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 02 0f 7f 09       	jmp    0x97f0f38
  36:	cc                   	int3
  37:	48 c7 c7 f1 c2 77 8d 	mov    $0xffffffff8d77c2f1,%rdi
  3e:	e8                   	.byte 0xe8
  3f:	c5                   	.byte 0xc5