glusterd-volgen: Enable open-behind based on op-version

Backport of patch on master branch, under review at
        http://review.gluster.org/4866

This patch enables the open-behind by default only when the op-version
allows it. Also the volume op-version calculations take account of this
enablement.

BUG: 954256
Change-Id: Ie739bc23ba90ec2f009feecef28187912a37487c
Signed-off-by: Kaushal M <kaushal@redhat.com>
Reviewed-on: http://review.gluster.org/5095
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

3 files changed, 50 insertions, 11 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-op-sm.c b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
index aa0543609e4..acd851663cb 100644
--- a/xlators/mgmt/glusterd/src/glusterd-op-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-op-sm.c
@@ -1619,6 +1619,19 @@ glusterd_op_set_volume (dict_t *dict)
                 goto out;
         }
 
+        /* Update the cluster op-version before regenerating volfiles so that
+         * correct volfiles are generated
+         */
+        if (new_op_version > priv->op_version) {
+                priv->op_version = new_op_version;
+                ret = glusterd_store_global_info (this);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Failed to store op-version");
+                        goto out;
+                }
+        }
+
         if (!global_opt) {
                 ret = glusterd_create_volfiles_and_notify_services (volinfo);
                 if (ret) {
@@ -1672,16 +1685,6 @@ glusterd_op_set_volume (dict_t *dict)
                 }
         }
 
-        if (new_op_version > priv->op_version) {
-                priv->op_version = new_op_version;
-                ret = glusterd_store_global_info (this);
-                if (ret) {
-                        gf_log (this->name, GF_LOG_ERROR,
-                                "Failed to store op-version");
-                        goto out;
-                }
-        }
-
  out:
         GF_FREE (key_fixed);
         gf_log (this->name, GF_LOG_DEBUG, "returning %d", ret);
diff --git a/xlators/mgmt/glusterd/src/glusterd-utils.c b/xlators/mgmt/glusterd/src/glusterd-utils.c
index 94bfe5fe137..0309a539cbe 100644
--- a/xlators/mgmt/glusterd/src/glusterd-utils.c
+++ b/xlators/mgmt/glusterd/src/glusterd-utils.c
@@ -7516,7 +7516,8 @@ _update_volume_op_versions (dict_t *this, char *key, data_t *value, void *data)
 void
 gd_update_volume_op_versions (glusterd_volinfo_t *volinfo)
 {
-        glusterd_conf_t    *conf = NULL;
+        glusterd_conf_t *conf = NULL;
+        gf_boolean_t    ob_enabled = _gf_false;
 
         GF_ASSERT (volinfo);
 
@@ -7529,5 +7530,26 @@ gd_update_volume_op_versions (glusterd_volinfo_t *volinfo)
 
         dict_foreach (volinfo->dict, _update_volume_op_versions, volinfo);
 
+        /* Special case for open-behind
+         * If cluster op-version >= 2 and open-behind hasn't been explicitly
+         * disabled, volume op-versions must be updated to account for it
+         */
+
+        /* TODO: Remove once we have a general way to update automatically
+         * enabled features
+         */
+        if (conf->op_version >= 2) {
+                ob_enabled = dict_get_str_boolean (volinfo->dict,
+                                                   "performance.open-behind",
+                                                   _gf_true);
+                if (ob_enabled) {
+
+                        if (volinfo->op_version < 2)
+                                volinfo->op_version = 2;
+                        if (volinfo->client_op_version < 2)
+                                volinfo->client_op_version = 2;
+                }
+        }
+
         return;
 }
diff --git a/xlators/mgmt/glusterd/src/glusterd-volgen.c b/xlators/mgmt/glusterd/src/glusterd-volgen.c
index ccfa28e3528..3d07412b207 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volgen.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volgen.c
@@ -460,6 +460,8 @@ process_option (dict_t *dict, char *key, data_t *value, void *param)
         vme.key = key;
         vme.voltype = odt->vme->voltype;
         vme.option = odt->vme->option;
+        vme.op_version = odt->vme->op_version;
+
         if (!vme.option) {
                 vme.option = strrchr (key, '.');
                 if (vme.option)
@@ -1673,6 +1675,12 @@ perfxl_option_handler (volgen_graph_t *graph, struct volopt_map_entry *vme,
 {
         char *volname = NULL;
         gf_boolean_t enabled = _gf_false;
+        xlator_t *this = NULL;
+        glusterd_conf_t *conf = NULL;
+
+        this = THIS;
+        GF_ASSERT (this);
+        conf = this->private;
 
         volname = param;
 
@@ -1684,6 +1692,12 @@ perfxl_option_handler (volgen_graph_t *graph, struct volopt_map_entry *vme,
         if (!enabled)
                 return 0;
 
+        /* Check op-version before adding the 'open-behind' xlator in the graph
+         */
+        if (!strcmp (vme->key, "performance.open-behind") &&
+            (vme->op_version > conf->op_version))
+                return 0;
+
         if (volgen_graph_add (graph, vme->voltype, volname))
                 return 0;
         else