INFO: task syz-executor:9720 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:17176 pid:9720  tgid:9720  ppid:1      task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 __closure_sync+0x163/0x220
 bch2_journal_flush_pins+0x18e/0x250
 __bch2_fs_read_only+0x144/0x5b0
 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: 0033:0x7f03c398ff57
RSP: 002b:00007fff6c3f64e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f03c3a11c2d RCX: 00007f03c398ff57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff6c3f65a0
RBP: 00007fff6c3f65a0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff6c3f7630
R13: 00007f03c3a11c2d R14: 0000000000056da6 R15: 00007fff6c3f7670
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/u10:7/1092:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90006fa7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by getty/5672:
 #0: ffff88811096d0a0 (&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 kworker/u9:7/8553:
 #0: ffff888120558148 ((wq_completion)btree_update){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90003067bc0 ((work_completion)(&c->btree_interior_update_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88812d584398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220
 #3: ffff88812d5a6710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0
2 locks held by syz-executor/9720:
 #0: ffff8881237ec0e0 (&type->s_umount_key#50){++++}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffff88812d580278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900
4 locks held by kworker/u8:3/11147:
 #0: ffff88801b2f7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002e6fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f52d310 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890
1 lock held by syz.7.1095/11287:
 #0: ffff8881237ec0e0 (&type->s_umount_key#50){++++}-{4:4}, at: super_lock+0x2a9/0x3b0
2 locks held by syz-executor/13670:
 #0: ffffffff8fa3e1c8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f53a1c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
1 lock held by syz.4.1589/13696:
 #0: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz.3.1590/13703:

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

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+0x439/0x7d0
 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: 11147 Comm: kworker/u8:3 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:zap_class+0xc2/0x360
Code: 49 81 fc 00 00 08 00 0f 84 a5 01 00 00 4e 8b 2c e5 40 b3 64 93 4d 85 ed 0f 94 c0 49 83 c5 f8 0f 94 c1 08 c1 75 d7 45 8b 7d 00 <41> f6 c7 fc 0f 84 e2 00 00 00 41 c1 ef 08 4e 8d 34 7d 10 b3 a9 92
RSP: 0018:ffffc90002e6f538 EFLAGS: 00000046
RAX: 0000000000048b00 RBX: 0000000000001077 RCX: 0000000000048b00
RDX: ffffffff9364b338 RSI: 0000000000000006 RDI: 0000000000086ce9
RBP: ffffffff93a8b7b0 R08: 0000000000000000 R09: ffffffff81aa9708
R10: dffffc0000000000 R11: fffffbfff1f474e7 R12: 0000000000061453
R13: ffffffff93d0b5d0 R14: ffffffff92b2cae4 R15: 000000000614c518
FS:  0000000000000000(0000) GS:ffff8880b8611000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b921febe68 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lockdep_unregister_key+0x1a6/0x310
 __qdisc_destroy+0x166/0x420
 dev_shutdown+0x34c/0x440
 unregister_netdevice_many_notify+0xe0f/0x1ff0
 default_device_exit_batch+0x819/0x890
 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>
