INFO: task syz-executor:9538 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:18856 pid:9538  tgid:9538  ppid:1      task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x9a/0x270
 wait_for_completion+0x2bf/0x5d0
 kthread_stop+0x194/0x5c0
 bch2_copygc_stop+0x4b/0x120
 __bch2_fs_read_only+0x47/0x5b0
 bch2_fs_read_only+0x42a/0xb00
 __bch2_fs_stop+0x100/0x900
 generic_shutdown_super+0x135/0x2c0
 bch2_kill_sb+0x41/0x50
 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: 0033:0x7f5ad598fed7
RSP: 002b:00007fffc31b6ee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f5ad5a11c05 RCX: 00007f5ad598fed7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffc31b6fa0
RBP: 00007fffc31b6fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffc31b8030
R13: 00007f5ad5a11c05 R14: 00000000000404b4 R15: 00007fffc31b8070
 </TASK>
INFO: task bch-copygc/loop:9999 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:bch-copygc/loop state:D stack:21768 pid:9999  tgid:9999  ppid:2      task_flags:0x240040 flags:0x00024000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 __closure_sync+0x163/0x220
 __bch2_write+0x31ef/0x3900
 bch2_moving_ctxt_do_pending_writes+0x5a7/0xe60
 bch2_move_ratelimit+0x8e8/0x1330
 __bch2_move_data_phys+0x18c1/0x1c50
 bch2_evacuate_bucket+0x228/0x3a0
 bch2_copygc+0x3be3/0x4510
 bch2_copygc_thread+0x97a/0xe00
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/u8:1/13:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90000107bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52d090 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffff888038c714e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x2f0
 #4: ffffffff8e13fa40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5676:
 #0: ffff8881066d50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by syz-executor/9538:
 #0: ffff888037b9e0e0 (&type->s_umount_key#57){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffff888116f80278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900
1 lock held by syz.2.858/12902:
 #0: ffff888037b9e0e0 (&type->s_umount_key#57){++++}-{4:4}, at: super_lock+0x25c/0x3b0
2 locks held by syz.7.1010/13433:
4 locks held by syz.8.1012/13441:
1 lock held by dhcpcd-run-hook/13448:

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

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+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 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: 13 Comm: kworker/u8:1 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
Workqueue: netns cleanup_net
RIP: 0010:rcu_is_watching+0x3a/0xb0
Code: e8 1b 01 d4 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 10 1d be 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 cc bf 7c 00 48 c7 c3 98 df a1 92 49 03 1e 48 89
RSP: 0018:ffffc90000107178 EFLAGS: 00000246
RAX: 1ffffffff1b7c3a3 RBX: 0000000000000001 RCX: da77b391a77a2100
RDX: ffffc90000107201 RSI: ffffffff8be33e60 RDI: ffffffff8be33e20
RBP: dffffc0000000000 R08: ffffc900001079b0 R09: 0000000000000000
R10: ffffc900001072b8 R11: fffff52000020e59 R12: ffffc900001079c0
R13: ffffc90000100000 R14: ffffffff8dbe1d18 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881a3c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f39dbe14000 CR3: 000000010a0bc000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 unwind_next_frame+0x1965/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 free_netdev+0x148/0x700
 netdev_run_todo+0xd0c/0xea0
 default_device_exit_batch+0x81e/0x890
 ops_undo_list+0x525/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
