cli/glusterd: add/remove brick fixes for arbiter volumes

1.Provide a command to convert replica 2 volumes to arbiter volumes.
Existing self-heal logic will automatically heal the file hierarchy into
the arbiter brick, the progress of which can be monitored using the
heal info command.

Syntax: gluster volume add-brick <VOLNAME> replica 3 arbiter 1
<HOST:arbiter-brick-path>

2. Add checks when removing bricks from arbiter volumes:
- When converting from arbiter to replica 2 volume, allow only arbiter
  brick to be removed.
- When converting from arbiter to plain distribute volume, allow only if
  arbiter is one of the bricks that is removed.

3. Some clean-up:
- Use GD_MSG_DICT_GET_SUCCESS instead of GD_MSG_DICT_GET_FAILED to
log messages that are not failures.
- Remove unused variable `brick_list`
- Move 'brickinfo->group' related functions to glusted-utils.

Change-Id: Ic87b8c7e4d7d3ab03f93e7b9f372b314d80947ce
BUG: 1318289
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/14126
Smoke: Gluster Build System <jenkins@build.gluster.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>

1 files changed, 6 insertions, 35 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-volgen.c b/xlators/mgmt/glusterd/src/glusterd-volgen.c
index 4321ddb7ddb..231117750f6 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volgen.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volgen.c
@@ -1547,16 +1547,8 @@ brick_graph_add_arbiter (volgen_graph_t *graph, glusterd_volinfo_t *volinfo,
         if (volinfo->arbiter_count != 1)
                 return 0;
 
-        /* Find the last brick in the same group. */
-        last = brickinfo;
-        for (;;) {
-                next = list_next (last, &volinfo->bricks,
-                                  glusterd_brickinfo_t, brick_list);
-                if (!next || (next->group != brickinfo->group)) {
-                        break;
-                }
-                last = next;
-        }
+        /* Add arbiter only if it is the last (i.e. 3rd) brick. */
+        last = get_last_brick_of_brick_group (volinfo, brickinfo);
         if (last != brickinfo)
                 return 0;
 
@@ -1623,22 +1615,6 @@ out:
         return ret;
 }
 
-void
-assign_brick_groups (glusterd_volinfo_t *volinfo)
-{
-        glusterd_brickinfo_t    *brickinfo      = NULL;
-        uint16_t                group_num       = 0;
-        int                     in_group        = 0;
-
-        list_for_each_entry (brickinfo, &volinfo->bricks, brick_list) {
-                brickinfo->group = group_num;
-                if (++in_group >= volinfo->replica_count) {
-                        in_group = 0;
-                        ++group_num;
-                }
-        }
-}
-
 static int
 brick_graph_add_changelog (volgen_graph_t *graph, glusterd_volinfo_t *volinfo,
                             dict_t *set_dict, glusterd_brickinfo_t *brickinfo)
@@ -5304,23 +5280,18 @@ get_parent_vol_tstamp_file (char *filename, glusterd_volinfo_t *volinfo)
 }
 
 void
-assign_groups (glusterd_volinfo_t *volinfo)
+assign_jbr_uuids (glusterd_volinfo_t *volinfo)
 {
         glusterd_brickinfo_t    *brickinfo      = NULL;
-        uint16_t                group_num       = 0;
         int                     in_group        = 0;
         uuid_t                  tmp_uuid;
 
         list_for_each_entry (brickinfo, &volinfo->bricks, brick_list) {
-                if (in_group == 0) {
+                if (in_group == 0)
                         gf_uuid_generate(tmp_uuid);
-                }
-                brickinfo->group = group_num;
                 gf_uuid_copy(brickinfo->jbr_uuid, tmp_uuid);
-                if (++in_group >= volinfo->replica_count) {
+                if (++in_group >= volinfo->replica_count)
                         in_group = 0;
-                        ++group_num;
-                }
         }
 }
 
@@ -5393,7 +5364,7 @@ generate_brick_volfiles (glusterd_volinfo_t *volinfo)
         }
 
         if (glusterd_volinfo_get_boolean(volinfo, "cluster.jbr") > 0) {
-                assign_groups(volinfo);
+                assign_jbr_uuids(volinfo);
         }
 
         ret = glusterd_volume_brick_for_each (volinfo, NULL,