Bug 1165097

Description of problem:
=======================

The data which is created from NFS client disappear for a brief when USS is enabled/disabled.

[root@wingo vol0]# ls
etc
[root@wingo vol0]# ls
etc  etc1
[root@wingo vol0]# ls
etc
[root@wingo vol0]# ls
etc  etc1
[root@wingo vol0]# ls
etc  etc1
[root@wingo vol0]# ls
etc
[root@wingo vol0]# ls
etc  etc1
[root@wingo vol0]# ls
etc  etc1

In the above output directory etc is created from the fuse mount and etc1 is created from the nfs mount. ls is performed from the fuse mount. And is happening whenever tried to enable/disable uss from server

Version-Release number of selected component (if applicable):
==============================================================

glusterfs-3.6.0.32-1.el6rhs.x86_64


How reproducible:
=================

Was able to reproduce multiple times


Steps to Reproduce:
===================
1. Create 4 node cluster 
2. Create and start 2x2 volume
3. Mount the volume (Fuse and NFS) on /mnt/vol0 and /mnt/nvol0 respectively
4. From Fuse cp -rf /etc /mnt/vol0/
5. From NFS cp -rf /etc /mnt/nvol0/etc1
6. From server do gluster volume set vol0 uss on/off in a loop
7. While uss enable/disable is in progress do ls from fuse mount on /mnt/vol0/

Actual results:
================

Some time it shows the data which is created from nfs and some times it doesn't show


Expected results:
=================

Data was created before performing enable/disable, it should show always


Additional info:
================

If not performing uss on/off, the data is always present