tests: Fix races in open-behind.t

Problems:
1) flush-behind is on by default, so just because write completes doesn't mean
   it will be on the disk, it could still be in write-behind's cache. This
   leads to failure where if you write from one mount and expect it to be there
   on the other mount, sometimes it won't be there.
2) Sometimes the graph switch is not completing by the time we issue read which
   is leading to opens not being sent on brick leading to failures.

Fixes:
1) Disable flush-behind
2) Add new functions to check the new graph is there and connected to bricks
   before 'cat' is executed.

BUG: 1379511
Change-Id: I0faed684e0dc70cfd2258ce6fdaed655ee915ae6
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>
Reviewed-on: http://review.gluster.org/15575
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

0 files changed, 0 insertions, 0 deletions