Bug 1367807

Description of problem:
=======================
created a 1x(4+2) volume and pumped data of about 70GB with following options
Options Reconfigured:
server.event-threads: 4
client.event-threads: 4
performance.client-io-threads: on
performance.readdir-ahead: on

Added another 4+2 distribute subvol and triggered rebalance

While the rebalance was happening(it showed completed on all other nodes while the localhost showed as inprogress), I triggered a rebalance stop==>stopped immediately.

I then immediately triggered rebalance start again, which said as below
[root@dhcp35-179 glusterfs]# gluster v rebal  ecvol42-clientio start
volume rebalance: ecvol42-clientio: failed: Rebalance on ecvol42-clientio is already started
[root@dhcp35-179 glusterfs]# gluster v info ecvol42-clientio

However , the rebalance status doesnt show any change

However, if i wait for some time say 5-10 min, then i am able to retrigger successfully.


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

[root@dhcp35-179 glusterfs]# rpm -qa|grep gluster
glusterfs-geo-replication-3.7.9-10.el7rhgs.x86_64
glusterfs-api-3.7.9-10.el7rhgs.x86_64
gluster-nagios-addons-0.2.7-1.el7rhgs.x86_64
vdsm-gluster-4.16.30-1.5.el7rhgs.noarch
python-gluster-3.7.9-10.el7rhgs.noarch
glusterfs-libs-3.7.9-10.el7rhgs.x86_64
glusterfs-client-xlators-3.7.9-10.el7rhgs.x86_64
gluster-nagios-common-0.2.4-1.el7rhgs.noarch
glusterfs-rdma-3.7.9-10.el7rhgs.x86_64
glusterfs-3.7.9-10.el7rhgs.x86_64
glusterfs-fuse-3.7.9-10.el7rhgs.x86_64
glusterfs-cli-3.7.9-10.el7rhgs.x86_64
glusterfs-server-3.7.9-10.el7rhgs.x86_64
[root@dhcp35-179 glusterfs]# 

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