glusterd/rebalance: initialize defrag variable after glusterd restart

During reblance restart after glusterd restarted, we are not
connecting to rebalance process from glusterd, because the
defrag variable in volinfo will be null.

Initializing the variable will connect the rpc

Back port of>
>Change-Id: Id820cad6a3634a9fc976427fbe1c45844d3d4b9b
>BUG: 1303028
>Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
>Reviewed-on: http://review.gluster.org/13319
>Smoke: Gluster Build System <jenkins@build.gluster.com>
>NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
>Reviewed-by: Dan Lambright <dlambrig@redhat.com>
>CentOS-regression: Gluster Build System <jenkins@build.gluster.com>

(cherry picked from commit a67331f3f79e827ffa4f7a547f6898e12407bbf9)

Change-Id: Ieec82a798da937002e09fb9325c93678a5eefca8
BUG: 1311041
Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
Reviewed-on: http://review.gluster.org/13494
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>

3 files changed, 47 insertions, 1 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-rebalance.c b/xlators/mgmt/glusterd/src/glusterd-rebalance.c
index 2ceab6d6d24..356cc909e17 100644
--- a/xlators/mgmt/glusterd/src/glusterd-rebalance.c
+++ b/xlators/mgmt/glusterd/src/glusterd-rebalance.c
@@ -331,6 +331,40 @@ out:
         return ret;
 }
 
+int
+glusterd_rebalance_defrag_init (glusterd_volinfo_t *volinfo,
+                                defrag_cbk_fn_t cbk)
+
+{
+        glusterd_defrag_info_t  *defrag         = NULL;
+        int                      ret            = -1;
+
+        if (!volinfo->rebal.defrag) {
+                volinfo->rebal.defrag =
+                        GF_CALLOC (1, sizeof (*volinfo->rebal.defrag),
+                                   gf_gld_mt_defrag_info);
+        } else {
+                /*
+                 * if defrag variable is already initialized,
+                 * we skip the initialization.
+                 */
+                ret = 0;
+                goto out;
+        }
+
+        if (!volinfo->rebal.defrag)
+                goto out;
+        defrag = volinfo->rebal.defrag;
+
+        defrag->cmd = volinfo->rebal.defrag_cmd;
+        LOCK_INIT (&defrag->lock);
+        if (cbk)
+                defrag->cbk_fn = cbk;
+        ret = 0;
+out:
+        return ret;
+
+}
 
 int
 glusterd_rebalance_rpc_create (glusterd_volinfo_t *volinfo,
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index 11fe0481b77..a4d6ec592d9 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -7133,6 +7133,15 @@ glusterd_volume_defrag_restart (glusterd_volinfo_t *volinfo, char *op_errstr,
         case GF_DEFRAG_STATUS_STARTED:
                 GLUSTERD_GET_DEFRAG_PID_FILE(pidfile, volinfo, priv);
                 if (gf_is_service_running (pidfile, &pid)) {
+                        ret = glusterd_rebalance_defrag_init (volinfo, cbk);
+                        if (ret) {
+                                gf_msg (this->name, GF_LOG_ERROR, 0,
+                                        GD_MSG_REBALANCE_START_FAIL,
+                                        "Failed to initialize  defrag."
+                                        "Not starting rebalance process for "
+                                        "%s.", volinfo->volname);
+                                goto out;
+                        }
                         ret = glusterd_rebalance_rpc_create (volinfo, _gf_true);
                         break;
                 }
@@ -7148,7 +7157,7 @@ glusterd_volume_defrag_restart (glusterd_volinfo_t *volinfo, char *op_errstr,
                         volinfo->rebal.defrag_status, volinfo->volname);
                 break;
         }
-
+out:
         return ret;
 }
 
diff --git a/xlators/mgmt/glusterd/src/glusterd.h b/xlators/mgmt/glusterd/src/glusterd.h
index 3b7c82faab2..c872cd2339c 100644
--- a/xlators/mgmt/glusterd/src/glusterd.h
+++ b/xlators/mgmt/glusterd/src/glusterd.h
@@ -1004,6 +1004,9 @@ int
 glusterd_rebalance_rpc_create (glusterd_volinfo_t *volinfo,
                                gf_boolean_t reconnect);
 
+int glusterd_rebalance_defrag_init (glusterd_volinfo_t *volinfo,
+                                    defrag_cbk_fn_t cbk);
+
 int glusterd_handle_cli_heal_volume (rpcsvc_request_t *req);
 
 int glusterd_handle_cli_list_volume (rpcsvc_request_t *req);