INFO: task segctord:30970 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:segctord        state:D stack:28680 pid:30970 tgid:30970 ppid:2      task_flags:0x200040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x883/0x1080
 down_write+0x1bc/0x200
 nilfs_transaction_lock+0x252/0x4c0
 nilfs_segctor_thread+0x6b5/0xdc0
 kthread+0x389/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5442:
 #0: ffff8881125d00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
2 locks held by syz.5.6001/30966:
1 lock held by segctord/30970:
 #0: ffff888119e1e288 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_lock+0x252/0x4c0
5 locks held by syz.8.11657/21568:
2 locks held by syz.8.11657/21581:
 #0: ffff88816ed70438 (&mdev->req_queue_mutex){+.+.}-{4:4}, at: v4l2_release+0x152/0x370
 #1: ffff88816ed75e10 (&dev->mutex#3){+.+.}-{4:4}, at: vivid_fop_release+0x6c/0xaa0

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x389/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30966 Comm: syz.5.6001 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__lock_acquire+0xb17/0x2cf0
Code: c8 91 0e 48 c7 c6 f3 f2 0b 8e 67 48 0f b9 3a 90 48 bb eb 83 b5 80 46 86 c8 61 48 0f af dd 48 c1 eb 2d 48 8b 04 dd a0 e3 fb 93 <48> 85 c0 0f 94 c1 48 83 c0 f8 0f 94 c2 08 ca 0f 84 1c 01 00 00 e8
RSP: 0018:ffffc900083b7068 EFLAGS: 00000007
RAX: ffffffff949e4d78 RBX: 00000000000070d4 RCX: 0000000000040000
RDX: 00000000b75ac647 RSI: 0000000096ce966f RDI: ffff88811ba9bb80
RBP: 9742324ef880dfdb R08: ffffffff81a4c7ff R09: ffffffff8e94f058
R10: dffffc0000000000 R11: fffffbfff1cfd238 R12: ffff88811ba9c7b0
R13: ffff88811ba9c7b0 R14: ffff88811ba9bb80 R15: 0000000000000004
FS:  00007fe0dadde6c0(0000) GS:ffff88818dc9f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f833cbea540 CR3: 0000000188ee0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x106/0x350
 _raw_spin_lock+0x2e/0x40
 console_flush_all+0x67f/0xb20
 console_unlock+0xd1/0x1c0
 vprintk_emit+0x485/0x560
 _printk+0xdd/0x130
 __nilfs_msg+0x373/0x450
 nilfs_clean_segments+0x5b2/0xa50
 nilfs_ioctl+0x261f/0x2780
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe0d9f9ce59
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:00007fe0dadde028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe0da215fa0 RCX: 00007fe0d9f9ce59
RDX: 0000200000000640 RSI: 0000000040786e88 RDI: 0000000000000007
RBP: 00007fe0da032d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe0da216038 R14: 00007fe0da215fa0 R15: 00007ffe996b3318
 </TASK>
