arbiter: load arbiter xlator on every 3rd brick of a replica 3 AFR subvol

Logic for adding the 'glusterd_brickinfo->group' member and using it to
find the brick positon has been taken from http://review.gluster.org/#/c/9919.
Thanks to Jeff Darcy for that.

This patch is a part of the arbiter logic implementation for 3 way AFR
details of which can be found at http://review.gluster.org/#/c/9656/

Change-Id: Idbfe4f29ee8e098e0102def8f38b32314316b188
BUG: 1199985
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/10257
Tested-by: NetBSD Build System
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd.h b/xlators/mgmt/glusterd/src/glusterd.h
index ff63cce2234..60c3ebdf9bb 100644
--- a/xlators/mgmt/glusterd/src/glusterd.h
+++ b/xlators/mgmt/glusterd/src/glusterd.h
@@ -202,6 +202,15 @@ struct glusterd_brickinfo {
         char vg[PATH_MAX]; /* FIXME: Use max size for length of vg */
         int     caps; /* Capability */
         int32_t            snap_status;
+        /*
+         * The group is used to identify which bricks are part of the same
+         * replica set during brick-volfile generation, so that NSR volfiles
+         * can "cross-connect" the bricks to one another. It is also used by
+         * AFR to load the arbiter xlator in the appropriate brick in case of
+         * a replica 3 volume with arbiter enabled.
+         */
+        uint16_t           group;
+
 };
 
 typedef struct glusterd_brickinfo glusterd_brickinfo_t;