Tested with build glusterfs-3.7.5-7.el6rhs.x86_64: Created 2x2 volume and exported the samba share on windows client. Executed the perl script mentioned in bug description which creates nested folders and files. Executed add-brick operation while i/o's are going on. Executed rebalance. Mount point is still accessible and there are no I/O errors on windows client. Marking the BZ verified.
*** Bug 1092482 has been marked as a duplicate of this bug. ***
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2016-0193.html