geo-rep: use cold tier bricks for namespace operations

Problem:
symlinks are not getting synced to slave in a Tiering based volume.

Solution:
Now, symlinks are created directly in cold tier bricks( in the backend).

Earlier, cold tier was avoided for namespace operations and only
hot tier was used while processing changelogs.

Now, cold tier is HASH subvolume in a Tiering volume.
So, carry out namespace operation only in cold tier subvolume and
avoid hot tier subvolume to avoid any races.

Earlier, XSYNC was used(and changeloghistory avoided) during initial sync
in order to avoid race while processing historychangelog in Hot tier.
This is no longer required as there is no race from Hot tier.

Also, avoid both live and history changelog ENTRY operations from Hot tier
to avoid any race with cold tier.

Change-Id: Ia8fbb7ae037f5b6cb683f36c0df5c3fc2894636e
BUG: 1288027
Signed-off-by: Saravanakumar Arumugam <sarumuga@redhat.com>
Reviewed-on: http://review.gluster.org/12844
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kotresh HR <khiremat@redhat.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
(cherry picked from commit 93f31189ce8f6e2980a39b02568ed17088e0a667)
Reviewed-on: http://review.gluster.org/12891

0 files changed, 0 insertions, 0 deletions