When subvols-per-directory is < available subvols, then there are layouts
which are not populated. This leads to incorrect identification of holes or
overlaps. We need to ignore layouts, which have err == 0, and start == stop.
In the current scenario (start == stop == 0).

Additionally, in layout-merge, treat missing xattrs as err = 0. In case of
missing layouts, anomalies will reset them.

For any other valid subvoles, err != 0 in case of layouts being zeroed out.

Also reverted back dht_selfheal_dir_xattr, which does layout calculation only
on subvols which have errors.

Change-Id: I9f57062722c9e8a26285e10675c31a78921115a1
BUG: 921408
Signed-off-by: shishir gowda <sgowda@redhat.com>
Reviewed-on: http://review.gluster.org/4668
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>

If holes are encountered, then we do not write these to the dst,
which sometimes causes file size to be lesser than src. Data is not
corrupted, as when non-zero reads are received, we do write that data.

Calling a truncrate to give file size to prevent it from being
truncated to less than src in case the file end has holes.

Thanks to Brian Foster for providing the test case

Change-Id: I3cdd143b63ec8d797273d76189dff8b05eb9e551
BUG: 915554
Signed-off-by: shishir gowda <sgowda@redhat.com>
Reviewed-on: http://review.gluster.org/4574
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

Currently, linkfile creation happens as root.

use uid/gid returned from _cbk (link/rename) to set the correct ownership of
the link files.

Also added test/dht.rc to implement common dht functions

Change-Id: Iecdcf52d89fed8286670ce430b9d19deebd27b8c
BUG: 884597
Signed-off-by: shishir gowda <sgowda@redhat.com>
Reviewed-on: http://review.gluster.org/4304
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>