Description of problem:

Problem:
-------
While the glfs object of a volume is cached already,
if you delete the volume and create the volume with the same name, gluster-block currently uses the old volumes glfs object, which is not expected.

Why?
Because, current lru cache Hashing is based on volume name.

Solution:
--------
we would need to discard a cached object upon some number of failures or an option to explicitly discard an object from cache, or some equivalent policy