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
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 0x291/0x8a0 to_asm+ 0x40/0x70 pool+0x40/ 0x40 0x2c/0x80 timeout+ 0x1cf/0x350 0x9/0x10 0x9/0x10 cpu+0x11/ 0xb0 pool+0x40/ 0x40 for_completion+ 0xba/0x140 work+0x126/ 0x1e0 detach_ from_pool+ 0xa0/0xa0 work_timer+ 0x131/0x1b0 work_sync+ 0x10/0x20 put+0x1ab/ 0x400 [cifs] close+0x1e/ 0x40 [cifs] 0x1e/0x40 [cifs] work_run+ 0x9d/0xc0 to_usermode_ loop+0xc0/ 0xd0 64+0x115/ 0x130 SYSCALL_ 64_after_ hwframe+ 0x3d/0xa2 1c9898 EFLAGS: 00000206 ORIG_RAX: 0000000000000003
Call Trace:
__schedule+
? __switch_
? get_work_
schedule+
schedule_
? sched_clock+
? sched_clock+
? sched_clock_
? get_work_
wait_
? wake_up_q+0x80/0x80
flush_
? worker_
__cancel_
cancel_
cifsFileInfo_
cifs_
? cifs_close+
__fput+0xea/0x220
____fput+0xe/0x10
task_
exit_
do_syscall_
entry_
RIP: 0033:0x14f9e4ecf947
RSP: 002b:00007ffe59
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