cluster/afr: Fix per-txn optimistic changelog initialisation

        Backport of: http://review.gluster.org/16075

Incorrect initialisation of local->optimistic_change_log was leading
to skipped pre-op and post-op even when a brick didn't participate in
the txn because it was down.
The result - missing granular name index resulting in some entries
never getting healed.

FIX:
Initialise local->optimistic_change_log just before pre-op.

Also fixed granular entry heal to create the granular name index in
pre-op as opposed to post-op. This is to prevent loss of granular
information when during an entry txn, the good (src) brick goes
offline before the post-op is done. This would cause self-heal to
do conservative merge (since dirty xattr is the only information
available), which when granular-entry-heal is enabled, expects
granular indices, the lack of which can lead to loss of data in
the worst case.

Change-Id: Ibc0fbfb3fa21c578e28868d9e30b274e33c12064
BUG: 1403646
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/16105
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
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