Locking does not work on file systems using bindfs about bindfs HOT 5 CLOSED

#!/usr/bin/python
import fcntl, os, time
fd = open('./lockfile', 'w')
fcntl.lockf(fd, fcntl.LOCK_EX|fcntl.LOCK_NB)
time.sleep(30)
fcntl.lockf(fd, fcntl.LOCK_UN)
fd.close()

root@ubuntu:/test/bindfs1# ./fcntl-locktest &
[1] 5159
root@ubuntu:/test/bindfs1# ./fcntl-locktest
Traceback (most recent call last):
  File "./fcntl-locktest", line 5, in <module>
    fcntl.lockf(fd, fcntl.LOCK_EX|fcntl.LOCK_NB)
IOError: [Errno 11] Resource temporarily unavailable

root@ubuntu:/test/bindfs1# ./fcntl-locktest &
[1] 5161
root@ubuntu:/test/bindfs1# cd ../bindfs2
root@ubuntu:/test/bindfs2# ./fcntl-locktest

root@ubuntu:/test/bindfs1# ./fcntl-locktest &
[1] 5165
root@ubuntu:/test/bindfs1# cd ../realfs/
root@ubuntu:/test/realfs# ./fcntl-locktest

root@ubuntu-14:/test/bindfs1# which bindfs
/usr/local/bin/bindfs
root@ubuntu-14:/test/bindfs1# bindfs -V
bindfs 1.13.1
root@ubuntu-14:~# mkdir -p /test/realfs /test/bindfs1 /test/bindfs2
root@ubuntu-14:~# bindfs /test/realfs /test/bindfs1
root@ubuntu-14:~# bindfs /test/realfs /test/bindfs2
root@ubuntu-14:~# flock -n -x -o /test/bindfs1/lockfile sleep 30 &
[1] 1734
root@ubuntu-14:~# flock -n -x -o /test/bindfs2/lockfile sleep 10
root@ubuntu-14:~# echo $?
0

root@ubuntu-14:~# bindfs --enable-lock-forwarding --enable-ioctl --multithreaded /test/realfs /test/bindfs1
root@ubuntu-14:~# bindfs --enable-lock-forwarding --enable-ioctl --multithreaded /test/realfs /test/bindfs2
root@ubuntu-14:~# flock -n -x -o /test/bindfs1/lockfile sleep 30 &
[1] 1798
root@ubuntu-14:~# flock -n -x -o /test/bindfs2/lockfile sleep 10
root@ubuntu-14:~# echo $?
1