rebalance/glusterd: Refactor rebalance volfile

performance xlator loaded in rebalance xlators are dummy
translators, since all fops are starting with dht level.

Removing the performance xlators from rebalance volfile
will help to minimize the chance for a graph switch.

The new rebalance xlators will look like->>>

                        (io-stats)
                            ||
                            ||
                            ||
                       (----DHT----)
                      //          \\
                     //            \\
                    //              \\
              (replica-1)  ...   (replica-n)
              //      \\          //      \\
             //        \\        //        \\
            //          \\      //          \\
         client       client  client       client

Change-Id: I3808e3b48fd0cb3e60ef386b8ac9fd994e2831e3
BUG: 1240621
Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
Reviewed-on: http://review.gluster.org/11565
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>

1 files changed, 74 insertions, 24 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-volgen.c b/xlators/mgmt/glusterd/src/glusterd-volgen.c
index 448ee7908c7..75f64fad2c0 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volgen.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volgen.c
@@ -3534,7 +3534,6 @@ client_graph_builder (volgen_graph_t *graph, glusterd_volinfo_t *volinfo,
         gf_boolean_t     var           = _gf_false;
         gf_boolean_t     ob            = _gf_false;
         gf_boolean_t     uss_enabled   = _gf_false;
-        gf_boolean_t     rebal_volfile = _gf_false;
         xlator_t        *this          = THIS;
 
         GF_ASSERT (this);
@@ -3752,19 +3751,12 @@ client_graph_builder (volgen_graph_t *graph, glusterd_volinfo_t *volinfo,
         if (uss_enabled == -1)
                 goto out;
         if (uss_enabled && !volinfo->is_snap_volume) {
-                rebal_volfile = dict_get_str_boolean (set_dict,
-                                                   "rebalance-volfile-creation",
-                                                   _gf_false);
-                if (rebal_volfile == -1)
-                        goto out;
 
-                if (!rebal_volfile) {
-                        ret = volgen_graph_build_snapview_client
-                                                   (graph, volinfo,
-                                                    volname, set_dict);
-                        if (ret == -1)
-                                goto out;
-                }
+                ret = volgen_graph_build_snapview_client
+                                           (graph, volinfo,
+                                            volname, set_dict);
+                if (ret == -1)
+                        goto out;
         }
 
         ret = dict_get_str_boolean (set_dict, "ganesha.enable", _gf_false);
@@ -4212,6 +4204,73 @@ out:
 }
 
 static int
+build_rebalance_volfile (glusterd_volinfo_t *volinfo, char *filepath,
+                         dict_t *mod_dict)
+{
+        volgen_graph_t          graph           = {0,};
+        xlator_t                *xl             = NULL;
+        int                     ret             = -1;
+        xlator_t                *this           = NULL;
+        dict_t                  *set_dict       = NULL;
+
+        this = THIS;
+
+        if (volinfo->brick_count <= volinfo->dist_leaf_count) {
+                /*
+                 * Volume is not a distribute volume or
+                 * contains only 1 brick, no need to create
+                 * the volfiles.
+                 */
+                return 0;
+        }
+
+        if (mod_dict) {
+                set_dict = dict_copy (volinfo->dict, NULL);
+                if (!set_dict)
+                        return -1;
+                 dict_copy (mod_dict, set_dict);
+                 /* XXX dict_copy swallows errors */
+        } else {
+                set_dict = volinfo->dict;
+        }
+
+
+        ret = volgen_graph_build_clients (&graph, volinfo, set_dict, NULL);
+        if (volinfo->type == GF_CLUSTER_TYPE_TIER)
+                ret = volume_volgen_graph_build_clusters_tier
+                                        (&graph, volinfo, _gf_false);
+        else
+                ret = volume_volgen_graph_build_clusters
+                                        (&graph, volinfo, _gf_false);
+
+        xl = volgen_graph_add_as (&graph, "debug/io-stats", volinfo->volname);
+        if (!xl) {
+                ret = -1;
+                goto out;
+        }
+
+        ret = graph_set_generic_options (this, &graph, set_dict,
+                                         "rebalance-daemon");
+        if (ret)
+                goto out;
+
+        ret = volgen_graph_set_options_generic (&graph, set_dict, volinfo,
+                                                basic_option_handler);
+
+        if (!ret)
+                ret = volgen_write_volfile (&graph, filepath);
+
+out:
+        volgen_graph_free (&graph);
+
+        if (mod_dict)
+                dict_destroy (set_dict);
+
+
+        return ret;
+
+}
+static int
 build_shd_volume_graph (xlator_t *this, volgen_graph_t *graph,
                         glusterd_volinfo_t *volinfo,
                         dict_t *mod_dict, dict_t *set_dict,
@@ -4871,19 +4930,10 @@ generate_client_volfiles (glusterd_volinfo_t *volinfo,
         }
 
         /* Generate volfile for rebalance process */
-        ret = dict_set_int32 (dict, "rebalance-volfile-creation", _gf_true);
-        if (ret) {
-                gf_msg (this->name, GF_LOG_ERROR, errno,
-                        GD_MSG_DICT_SET_FAILED,
-                        "Failed to set rebalance-volfile-creation");
-                goto out;
-        }
-
         glusterd_get_rebalance_volfile (volinfo, filepath, PATH_MAX);
+        ret = build_rebalance_volfile (volinfo, filepath, dict);
+
 
-        ret = generate_single_transport_client_volfile (volinfo,
-                                                        filepath,
-                                                        dict);
         if (ret) {
                 gf_msg (this->name, GF_LOG_ERROR, 0,
                         GD_MSG_VOLFILE_CREATE_FAIL,