4171 clean up spa_feature_*() interfaces
4172 implement extensible_dataset feature for use by other zpool features
Reviewed by: Max Grossman <max.grossman@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>

@@ -2298,18 +2298,16 @@
                 }
 
                 enabled_feat = fnvlist_alloc();
                 unsup_feat = fnvlist_alloc();
 
-                if (!feature_is_supported(spa->spa_meta_objset,
-                    spa->spa_feat_for_read_obj, spa->spa_feat_desc_obj,
+                if (!spa_features_check(spa, B_FALSE,
                     unsup_feat, enabled_feat))
                         missing_feat_read = B_TRUE;
 
                 if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
-                        if (!feature_is_supported(spa->spa_meta_objset,
-                            spa->spa_feat_for_write_obj, spa->spa_feat_desc_obj,
+                        if (!spa_features_check(spa, B_TRUE,
                             unsup_feat, enabled_feat)) {
                                 missing_feat_write = B_TRUE;
                         }
                 }
 

@@ -5912,23 +5910,23 @@
                 uint64_t intval;
                 char *strval, *fname;
                 zpool_prop_t prop;
                 const char *propname;
                 zprop_type_t proptype;
-                zfeature_info_t *feature;
+                spa_feature_t fid;
 
                 switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
                 case ZPROP_INVAL:
                         /*
                          * We checked this earlier in spa_prop_validate().
                          */
                         ASSERT(zpool_prop_feature(nvpair_name(elem)));
 
                         fname = strchr(nvpair_name(elem), '@') + 1;
-                        VERIFY0(zfeature_lookup_name(fname, &feature));
+                        VERIFY0(zfeature_lookup_name(fname, &fid));
 
-                        spa_feature_enable(spa, feature, tx);
+                        spa_feature_enable(spa, fid, tx);
                         spa_history_log_internal(spa, "set", tx,
                             "%s=enabled", nvpair_name(elem));
                         break;
 
                 case ZPOOL_PROP_VERSION: