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

Consider a entry scenario where shared volume is enabled and mounted on all nodes of trusted servers. Now if any glusterd is down and shared volume is disabled, it returns success and any subsequent enable/disable blame it exists/non-exist respectively.


[root@dhcp41-226 ~]# gluster volume set all cluster.enable-shared-storage enable
volume set: failed: Shared storage volume(gluster_shared_storage) already exists.
[root@dhcp41-226 ~]# gluster volume set all cluster.enable-shared-storage disable
Disabling cluster.enable-shared-storage will delete the shared storage volume(gluster_shared_storage), which is used by snapshot scheduler, geo-replication and NFS-Ganesha. Do you still want to continue? (y/n) y
volume set: failed: Shared storage volume does not exist. Please enable shared storage for creating shared storage volume.
[root@dhcp41-226 ~]# gluster volume set all cluster.enable-shared-storage enable
volume set: failed: Shared storage volume(gluster_shared_storage) already exists.
[root@dhcp41-226 ~]# gluster volume set all cluster.enable-shared-storage disable
Disabling cluster.enable-shared-storage will delete the shared storage volume(gluster_shared_storage), which is used by snapshot scheduler, geo-replication and NFS-Ganesha. Do you still want to continue? (y/n) y
volume set: failed: Shared storage volume does not exist. Please enable shared storage for creating shared storage volume.
[root@dhcp41-226 ~]# 

No force option is available to come out of this dead loop. volume Stop/Start force also did not help. 

Workaround: 
[root@dhcp41-226 ~]# gluster volume stop gluster_shared_storage force
Stopping the shared storage volume(gluster_shared_storage), will affect features like snapshot scheduler, geo-replication and NFS-Ganesha. Do you still want to continue? (y/n) y
volume stop: gluster_shared_storage: success
[root@dhcp41-226 ~]# gluster volume delete gluster_shared_storage
Deleting the shared storage volume(gluster_shared_storage), will affect features like snapshot scheduler, geo-replication and NFS-Ganesha. Do you still want to continue? (y/n) y
volume delete: gluster_shared_storage: success
[root@dhcp41-226 ~]# gluster volume set all cluster.enable-shared-storage enable
volume set: success
[root@dhcp41-226 ~]#

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

glusterfs-server-3.12.2-7.el7rhgs.x86_64

How reproducible:
=================
2/2


Steps to Reproduce:
===================
1. Enable shared volume
2. Stop glusterd on one of the node
3. Disable shared volume (Shared volume disables successfully. )
4. Start glusterd on the node
5. Try enable/disable of shared volume. 

Actual results:
Enable complains that the shared volume exists and disable complains that the shared volume does not exist. For a user it is like a dead-lock where enable/disable doesnt work and doesnt mount the shared volume to local host.