Description of problem:
heal-info slow response while IO is in progress

Version-Release number of selected component (if applicable):
3.6.9

How reproducible:


Steps to Reproduce:
1.
2.
3.

Actual results:
gluster v heal VOLNAME info 
is blocked

Expected results:
gluster v heal VOLNAME info 
is not blockedblocked

Additional info:
backporting of 
cluster/afr: Fix heal-info slow response while IO is in progress
Now heal-info does an open() on the file being examined so that
the client at some point sees open-fd count being > 1 and releases
the eager-lock so that heal-info doesn't remain blocked forever
until IO completes.

Change-Id: Icc478098e2bc7234408728b54d8185102b3540dc
BUG: 1297695
Signed-off-by: Krutika Dhananjay <kdhananj>
Reviewed-on: http://review.gluster.org/13326
Reviewed-by: Ravishankar N <ravishankar>
Smoke: Gluster Build System <jenkins.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu>
Tested-by: Pranith Kumar Karampuri <pkarampu>
NetBSD-regression: NetBSD Build System <jenkins.org>
CentOS-regression: Gluster Build System <jenkins.com>

requested for 3.6 branch