INFO: task kworker/u9:3:342 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u9:3    state:D stack:21352 pid:342   tgid:342   ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:7)
Call Trace:
 <TASK>
 __schedule+0x15dd/0x52d0
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7fe/0x1300
 jfs_commit_inode+0x1ca/0x530
 jfs_write_inode+0x145/0x220
 __writeback_single_inode+0x75a/0x11a0
 writeback_sb_inodes+0x992/0x1a20
 __writeback_inodes_wb+0x111/0x240
 wb_writeback+0x46a/0xb70
 wb_workfn+0xb4c/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>

Showing all locks held in the system:
3 locks held by kworker/0:1/10:
 #0: ffff88810006b148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc900000f7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffff888170bd0240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
2 locks held by kworker/u10:0/27:
 #0: ffff888162a86148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffff88823c624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
1 lock held by khungtaskd/34:
 #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/u9:3/342:
 #0: ffff888162a86148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90003e17c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffff888103be80e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
 #3: ffff888023d638b8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530
2 locks held by getty/5633:
 #0: ffff8881125c20a0 (&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
3 locks held by kworker/0:4/5874:
 #0: ffff88810006b148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0
 #1: ffffc90006567c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0
 #2: ffff8881111cf240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0
4 locks held by syz.7.471/8554:
2 locks held by syz.1.603/9516:
 #0: ffff888103be80e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
 #1: ffff888105b60820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c2/0xbd0
2 locks held by syz.1.603/9517:
 #0: ffff888103be80e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
 #1: ffff888105b60820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c2/0xbd0
2 locks held by syz.1.603/9519:
 #0: ffff888103be80e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
 #1: ffff888105b60820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c2/0xbd0
1 lock held by syz-executor/9844:
 #0: ffffffff8e7647b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by dhcpcd/10508:
 #0: ffff888023fe7408 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240
1 lock held by dhcpcd/10606:
 #0: ffff888118022c08 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240
1 lock held by syz.7.914/11954:
 #0: ffff888103be80e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x289/0x3d0
1 lock held by syz.6.1007/12713:
 #0: ffffffff8e7647b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
5 locks held by dhcpcd-run-hook/12739:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8554 Comm: syz.7.471 Not tainted syzkaller #0 PREEMPT(full) 
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+0x8/0x70
Code: 8b 3d f4 5e 55 0c 48 89 de 5b e9 23 8a 5e 00 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 18 5f 56 11 65 8b 15 39 5f 56 11 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90003a47680 EFLAGS: 00000246
RAX: ffffffff835ca9d6 RBX: 0000000000000004 RCX: 0000000000080000
RDX: ffffc90020b31000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffff888112316000 R08: 0000000200000000 R09: 0000000000000000
R10: 0030000000000000 R11: 000007ff00000020 R12: dffffc0000000000
R13: 1ffff11022462c00 R14: 0000000000000000 R15: 1ffff11022462c02
FS:  00007f43d65cc6c0(0000) GS:ffff8882a9460000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056504bc3f950 CR3: 000000010bd9a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 dtSplitRoot+0x7a6/0x16c0
 dtInsert+0xf19/0x5f10
 jfs_mkdir+0x783/0xb00
 vfs_mkdir+0x413/0x630
 filename_mkdirat+0x285/0x510
 __se_sys_mkdirat+0x35/0x150
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f43d579b607
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 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:00007f43d65cbe58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f43d65cbee0 RCX: 00007f43d579b607
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 00002000000003c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000003c0
R13: 00007f43d65cbea0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
