cli,glusterd: Implement 'volume status tasks'

oVirt's Gluster Integration needs an inexpensive command that can be
executed every 10 seconds to monitor async tasks and their parameters,
for all volumes.

The solution involves adding a 'tasks' sub-command to 'volume status'
to fetch only the async task IDs, type and other relevant parameters.
Only the originator glusterd participates in this command as all the
information needed is available on all the nodes. This is to make the
command suitable for being executed every 10 seconds.

Change-Id: I1edc607baf29b001a5585079dec681d7c641b3d1
BUG: 1012346
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/6006
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kaushal M <kaushal@redhat.com>

4 files changed, 91 insertions, 27 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-op-sm.c b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
index d7773599875..2dfe3cde109 100644
--- a/xlators/mgmt/glusterd/src/glusterd-op-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
@@ -2095,6 +2095,50 @@ out:
 }
 
 static int
+glusterd_aggregate_task_status (dict_t *rsp_dict, glusterd_volinfo_t *volinfo)
+{
+        int        ret   = -1;
+        int        tasks = 0;
+        xlator_t  *this  = NULL;
+
+        this = THIS;
+        GF_ASSERT (this);
+
+        if (!uuid_is_null (volinfo->rebal.rebalance_id)) {
+                ret = _add_task_to_dict (rsp_dict, volinfo, volinfo->rebal.op,
+                                         tasks);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Failed to add task details to dict");
+                        goto out;
+                }
+                tasks++;
+        }
+
+        if (!uuid_is_null (volinfo->rep_brick.rb_id)) {
+                ret = _add_task_to_dict (rsp_dict, volinfo, GD_OP_REPLACE_BRICK,
+                                         tasks);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Failed to add task details to dict");
+                        goto out;
+                }
+                tasks++;
+        }
+
+        ret = dict_set_int32 (rsp_dict, "tasks", tasks);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "Error setting tasks count in dict");
+                goto out;
+        }
+        ret = 0;
+
+out:
+        return ret;
+}
+
+static int
 glusterd_op_status_volume (dict_t *dict, char **op_errstr,
                            dict_t *rsp_dict)
 {
@@ -2114,7 +2158,6 @@ glusterd_op_status_volume (dict_t *dict, char **op_errstr,
         gf_boolean_t            nfs_disabled    = _gf_false;
         gf_boolean_t            shd_enabled     = _gf_true;
         gf_boolean_t            origin_glusterd = _gf_false;
-        int                     tasks           = 0;
 
         this = THIS;
         GF_ASSERT (this);
@@ -2197,6 +2240,10 @@ glusterd_op_status_volume (dict_t *dict, char **op_errstr,
                                                            brick_index);
                 node_count++;
 
+        } else if ((cmd & GF_CLI_STATUS_TASKS) != 0) {
+                ret = glusterd_aggregate_task_status (rsp_dict, volinfo);
+                goto out;
+
         } else {
                 list_for_each_entry (brickinfo, &volinfo->bricks, brick_list) {
                         brick_index++;
@@ -2278,31 +2325,10 @@ glusterd_op_status_volume (dict_t *dict, char **op_errstr,
             !origin_glusterd)
                 goto out;
 
-        if (!uuid_is_null (volinfo->rebal.rebalance_id)) {
-                ret = _add_task_to_dict (rsp_dict, volinfo, volinfo->rebal.op,
-                                         tasks);
-                if (ret) {
-                        gf_log (this->name, GF_LOG_ERROR,
-                                "Failed to add task details to dict");
-                        goto out;
-                }
-                tasks++;
-        }
-        if (!uuid_is_null (volinfo->rep_brick.rb_id)) {
-                ret = _add_task_to_dict (rsp_dict, volinfo, GD_OP_REPLACE_BRICK,
-                                         tasks);
-                if (ret) {
-                        gf_log (this->name, GF_LOG_ERROR,
-                                "Failed to add task details to dict");
-                        goto out;
-                }
-                tasks++;
-        }
-
-        ret = dict_set_int32 (rsp_dict, "tasks", tasks);
+        ret = glusterd_aggregate_task_status (rsp_dict, volinfo);
         if (ret)
-                gf_log (this->name, GF_LOG_ERROR,
-                        "Error setting tasks count in dict");
+                goto out;
+        ret = 0;
 
 out:
         gf_log (this->name, GF_LOG_DEBUG, "Returning %d", ret);
diff --git a/xlators/mgmt/glusterd/src/glusterd-syncop.c b/xlators/mgmt/glusterd/src/glusterd-syncop.c
index a854e053090..b3bab6fdcdd 100644
--- a/xlators/mgmt/glusterd/src/glusterd-syncop.c
+++ b/xlators/mgmt/glusterd/src/glusterd-syncop.c
@@ -1189,9 +1189,16 @@ gd_sync_task_begin (dict_t *op_ctx, rpcsvc_request_t * req)
          * the 'cluster' lock*/
         glusterd_op_set_op  (op);
         INIT_LIST_HEAD (&conf->xaction_peers);
-        npeers = gd_build_peers_list  (&conf->peers, &conf->xaction_peers, op);
 
-        ret = gd_lock_op_phase (&conf->xaction_peers, op, op_ctx, &op_errstr, npeers);
+        /* Make 'volume status tasks' command a local operation.
+         * This is accomplished by setting npeers to 0.
+         */
+        if (!glusterd_is_status_tasks_op (op, op_ctx))
+                npeers = gd_build_peers_list  (&conf->peers,
+                                               &conf->xaction_peers, op);
+
+        ret = gd_lock_op_phase (&conf->xaction_peers, op, op_ctx, &op_errstr,
+                                npeers);
         if (ret)
                 goto out;
 
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index b0f9a210f1c..bef3da74b40 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -6813,6 +6813,12 @@ glusterd_volume_status_copy_to_op_ctx_dict (dict_t *aggr, dict_t *rsp_dict)
                 }
         }
 
+        if ((cmd & GF_CLI_STATUS_TASKS) != 0) {
+                dict_copy (rsp_dict, aggr);
+                ret = 0;
+                goto out;
+        }
+
         ret = dict_get_int32 (rsp_dict, "count", &rsp_node_count);
         if (ret) {
                 ret = 0; //no bricks in the rsp
@@ -7695,3 +7701,26 @@ out:
         gf_log ("", GF_LOG_DEBUG, "Returning %d", ret);
         return ret;
 }
+
+gf_boolean_t
+glusterd_is_status_tasks_op (glusterd_op_t op, dict_t *dict)
+{
+        int           ret             = -1;
+        uint32_t      cmd             = GF_CLI_STATUS_NONE;
+        gf_boolean_t  is_status_tasks = _gf_false;
+
+        if (op != GD_OP_STATUS_VOLUME)
+                goto out;
+
+        ret = dict_get_uint32 (dict, "cmd", &cmd);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_ERROR, "Failed to get opcode");
+                goto out;
+        }
+
+        if (cmd & GF_CLI_STATUS_TASKS)
+                is_status_tasks = _gf_true;
+
+out:
+        return is_status_tasks;
+}
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.h b/xlators/mgmt/glusterd/src/glusterd-utils.h
index 89888b41920..34143cf6268 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.h
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.h
@@ -565,4 +565,6 @@ glusterd_check_gsync_running_local (char *master, char *slave,
                                     char *conf_path,
                                     gf_boolean_t *is_run);
 
+gf_boolean_t
+glusterd_is_status_tasks_op (glusterd_op_t op, dict_t *dict);
 #endif