INFO: task kworker/u9:3:998 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:20584 pid:998   tgid:998   ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:9)
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 jfs_commit_inode+0x1ca/0x530
 jfs_write_inode+0x145/0x220
 __writeback_single_inode+0x6f1/0xff0
 writeback_sb_inodes+0x6c7/0x1010
 __writeback_inodes_wb+0x111/0x240
 wb_writeback+0x44f/0xaf0
 wb_workfn+0x90b/0xef0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
INFO: task syz.4.682:10240 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.682       state:D stack:25128 pid:10240 tgid:10239 ppid:6872   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 wb_wait_for_completion+0x15f/0x260
 sync_inodes_sb+0x1bb/0xa10
 __iterate_supers+0x13d/0x290
 ksys_sync+0x94/0x150
 __ia32_sys_sync+0xe/0x20
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f188978ebe9
RSP: 002b:00007f188a5da038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f18899c5fa0 RCX: 00007f188978ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f18899c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f18899c6038 R14: 00007f18899c5fa0 R15: 00007ffd71527c78
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
4 locks held by kworker/u9:3/998:
 #0: ffff8881026ff948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90006b17bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88801eac80e0 (&type->s_umount_key#54){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0
 #3: ffff88802cd6f068 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530
2 locks held by getty/5675:
 #0: ffff8880257b00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by syz.9.668/10140:
2 locks held by syz.4.682/10240:
 #0: ffff88801eac80e0 (&type->s_umount_key#54){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff88810981a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
2 locks held by syz.0.854/12665:
 #0: ffff88801eac80e0 (&type->s_umount_key#54){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
 #1: ffff88810981a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10
1 lock held by syz-executor/12950:
 #0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
2 locks held by syz-executor/13125:
 #0: ffffffff8f538888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
 #1: ffff8881230dcd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: do_setlink+0x388/0x41c0
2 locks held by syz.9.889/13238:

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

NMI backtrace for cpu 1
CPU: 1 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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 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: 12950 Comm: syz-executor 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:io_serial_out+0x7c/0xc0
Code: 78 70 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 3c e6 d3 fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d e9 97 57 2d 06 cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc9000370f4f0 EFLAGS: 00000002
RAX: 0000000000000020 RBX: 0000000000000020 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff88801f5a0237 R09: 1ffff11003eb4046
R10: dffffc0000000000 R11: ffffffff854f3300 R12: dffffc0000000000
R13: ffffffff99afa8c2 R14: ffffffff99def420 R15: 0000000000000000
FS:  000055558bf1c500(0000) GS:ffff8880b861b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056148aa49000 CR3: 000000002d96c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 serial8250_console_write+0x1410/0x1ba0
 console_flush_all+0x728/0xc40
 console_unlock+0xc4/0x270
 vprintk_emit+0x5b7/0x7a0
 _printk+0xcf/0x120
 xfs_printk_level+0x18b/0x280
 xfs_health_unmount+0x2d8/0x4f0
 xfs_unmountfs+0x152/0x320
 xfs_fs_put_super+0x65/0x160
 generic_shutdown_super+0x135/0x2c0
 kill_block_super+0x44/0x90
 xfs_kill_sb+0x15/0x50
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f54edf8ff17
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe582143c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f54ee011c05 RCX: 00007f54edf8ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe58214480
RBP: 00007ffe58214480 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe58215510
R13: 00007f54ee011c05 R14: 0000000000061688 R15: 00007ffe58215550
 </TASK>
