INFO: task kworker/u10:2:40 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:2   state:D stack:21168 pid:40    tgid:40    ppid:2      task_flags:0x4208160 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x899/0x1040
 down_write+0x1bc/0x200
 nilfs_transaction_lock+0x252/0x4c0
 nilfs_construct_dsync_segment+0x15d/0x700
 do_writepages+0x32e/0x550
 __writeback_single_inode+0x133/0x11a0
 writeback_sb_inodes+0x992/0x1a20
 wb_writeback+0x456/0xb70
 wb_workfn+0x414/0xf50
 process_scheduled_works+0xb6e/0x18c0
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task segctord:11850 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:11850 tgid:11850 ppid:2      task_flags:0x200040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x899/0x1040
 down_write+0x1bc/0x200
 nilfs_transaction_lock+0x252/0x4c0
 nilfs_segctor_thread+0x6b5/0xdc0
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz.3.7289:1586 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.7289      state:D stack:25760 pid:1586  tgid:1580  ppid:1465   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 wb_wait_for_completion+0x3e8/0x790
 sync_inodes_sb+0x1de/0xbd0
 sync_filesystem+0x17a/0x230
 fs_bdev_sync+0x2c/0x50
 blkdev_common_ioctl+0x12e1/0x3250
 blkdev_ioctl+0x528/0x740
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74f919c819
RSP: 002b:00007f74fa024028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f74f9416090 RCX: 00007f74f919c819
RDX: 0000000000000000 RSI: 0000000000001261 RDI: 000000000000000b
RBP: 00007f74f9232c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f74f9416128 R14: 00007f74f9416090 R15: 00007ffdce8d3328
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u10:2/40:
 #0: ffff8881622ee148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: 
ffffc90000b07c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffff88801f1212a0 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_lock+0x252/0x4c0
2 locks held by getty/5635:
 #0: ffff888109f1a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0
7 locks held by syz.3.1178/11849:
1 lock held by segctord/11850:
 #0: ffff88801f1212a0 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_lock+0x252/0x4c0
2 locks held by syz.3.7289/1586:
 #0: ffff8881113e00e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
 #1: ffff88810732e820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c2/0xbd0
3 locks held by syz.4.8073/4863:

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

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+0xfd9/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x51e/0xb90
 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: 11849 Comm: syz.3.1178 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:__sanitizer_cov_trace_pc+0x17/0x70
Code: cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 98 4a 56 11 65 8b 15 b9 4a 56 11 <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 a4 16 00 00
RSP: 0018:ffffc9000b88f238 EFLAGS: 00000083
RAX: ffffffff853da48f RBX: 000000000000001f RCX: ffff888111578000
RDX: 0000000080000001 RSI: 0000000000000000 RDI: 0000000000000021
RBP: ffffc9000b88f370 R08: ffffffff81a49ef3 R09: ffffffff8e750b80
R10: dffffc0000000000 R11: ffffffff853da440 R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff9a2b4a40 R15: 0000000000000000
FS:  00007fd6e4db36c0(0000) GS:ffff88818de62000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000113258000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 univ8250_console_write+0x4f/0xa0
 console_flush_all+0x718/0xb20
 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+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd6e3f9c819
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:00007fd6e4db3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd6e4215fa0 RCX: 00007fd6e3f9c819
RDX: 0000200000000340 RSI: 0000000040786e88 RDI: 0000000000000004
RBP: 00007fd6e4032c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd6e4216038 R14: 00007fd6e4215fa0 R15: 00007ffd0c994698
 </TASK>
