Comment 12 for bug 1824981

Actually there is one waiting in state flush_work, one in call_rwsem_down_read_failed and 12 in call_rwsem_down_write_failed.

The "flush_work" task call trace

 genesplicer D 0 53332 52566 0x00000000
 Call Trace:
  __schedule+0x291/0x8a0
  ? __switch_to_asm+0x40/0x70
  ? get_work_pool+0x40/0x40
  schedule+0x2c/0x80
  schedule_timeout+0x1cf/0x350
  ? sched_clock+0x9/0x10
  ? sched_clock+0x9/0x10
  ? sched_clock_cpu+0x11/0xb0
  ? get_work_pool+0x40/0x40
  wait_for_completion+0xba/0x140
  ? wake_up_q+0x80/0x80
  flush_work+0x126/0x1e0
  ? worker_detach_from_pool+0xa0/0xa0
  __cancel_work_timer+0x131/0x1b0
  cancel_work_sync+0x10/0x20
  cifsFileInfo_put+0x1ab/0x400 [cifs]
  cifs_close+0x1e/0x40 [cifs]
  ? cifs_close+0x1e/0x40 [cifs]
  __fput+0xea/0x220
  ____fput+0xe/0x10
  task_work_run+0x9d/0xc0
  exit_to_usermode_loop+0xc0/0xd0
  do_syscall_64+0x115/0x130
  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
 RIP: 0033:0x14f9e4ecf947
 RSP: 002b:00007ffe591c9898 EFLAGS: 00000206 ORIG_RAX: 0000000000000003
 RAX: 0000000000000000 RBX: 000056367a99e260 RCX: 000014f9e4ecf947
 RDX: 000014f9e51a6760 RSI: 0000000000000001 RDI: 000000000000000b
 RBP: 000014f9e51a72a0 R08: 000014f9e53c14c0 R09: 0000000000000000
 R10: 000014f9e4f5dcc0 R11: 0000000000000206 R12: 0000000000000000
 R13: 00007ffe592be0a0 R14: 0000000000000000 R15: 0000000000000000