INFO: task kworker/u10:6:1111 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u10:6   state:D stack:21344 pid:1111  tgid:1111  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_write_slowpath+0x883/0x1080
 down_write+0x1bc/0x200
 f2fs_issue_checkpoint+0x437/0x790
 f2fs_balance_fs_bg+0x576/0x990
 f2fs_write_node_pages+0x158/0x700
 do_writepages+0x32e/0x550
 __writeback_single_inode+0x133/0x10e0
 writeback_sb_inodes+0x979/0x19d0
 __writeback_inodes_wb+0x111/0x240
 wb_writeback+0x459/0xb00
 wb_workfn+0xb12/0xf10
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 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: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/u10:6/1111:
 #0: ffff8881622df940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc900075e7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffff88810aef40d8 (&type->s_umount_key#72){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
 #3: ffff88811448d4b8 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_issue_checkpoint+0x437/0x790
2 locks held by getty/5441:
 #0: ffff8881754d90a0 (&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
3 locks held by syz-executor/16877:
3 locks held by syz.2.1469/17334:
2 locks held by syz-executor/18731:
1 lock held by syz-executor/20249:
3 locks held by syz.5.1852/20993:
1 lock held by syz.3.1851/20994:

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

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+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 20993 Comm: syz.5.1852 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:asm_sysvec_apic_timer_interrupt+0x0/0x20
Code: b6 79 a9 0a e9 81 06 00 00 90 f3 0f 1e fa 0f 1f 00 fc 6a ff e8 31 05 00 00 48 89 c4 48 89 e7 e8 c6 78 a9 0a e9 61 06 00 00 90 <f3> 0f 1e fa 0f 1f 00 fc 6a ff e8 11 05 00 00 48 89 c4 48 89 e7 e8
RSP: 0018:ffffc90007366dd8 EFLAGS: 00000046
RAX: ffffffff81a49855 RBX: ffffffff81a496cf RCX: 0000000000080000
RDX: ffffc9002e40c000 RSI: 000000000007ffff RDI: ffffffff8e94f1a0
RBP: ffffc90007366eb0 R08: ffffffff9030e1f7 R09: 1ffffffff2061c3e
R10: dffffc0000000000 R11: fffffbfff2061c3f R12: 0000000000000000
R13: 000000000000002f R14: 0000000000000200 R15: 1ffff92000e6cdc4
FS:  00007ff6f84fb6c0(0000) GS:ffff8882a9287000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555595685e28 CR3: 000000016ba96000 CR4: 00000000000006f0
Call Trace:
 <TASK>
RIP: 0010:vprintk_emit+0x45d/0x560
Code: 0f 84 44 ff ff ff e8 92 29 21 00 fb eb 44 e8 8a 29 21 00 e8 d5 fc 04 0a 4d 85 f6 74 94 e8 7b 29 21 00 fb 48 c7 c7 a0 f1 94 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 18
RSP: 0018:ffffc90007366e00 EFLAGS: 00000246
 _printk+0xdd/0x130
 set_capacity_and_notify+0x2c5/0x320
 loop_set_size+0x44/0xb0
 loop_configure+0x9ac/0xdf0
 lo_ioctl+0x447/0x1fb0
 blkdev_ioctl+0x5e3/0x740
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff6f759ca6b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007ff6f84fadb0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007ff6f759ca6b
RDX: 0000000000000004 RSI: 0000000000004c00 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007ff6f84faee0 R14: 00007ff6f84faea0 R15: 00007ff6ed200000
 </TASK>
