s4:dsdb Don't load the schema unconditionally

Schema loads now come at a price, so avoid doing them if we don't have
to (such as when doing an @REPLCHANGED or other special DN based
search).

Andrew Bartlett

1 files changed, 14 insertions, 3 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/schema_data.c b/source4/dsdb/samdb/ldb_modules/schema_data.c
index 25f2dcec8b..655b4892af 100644
--- a/source4/dsdb/samdb/ldb_modules/schema_data.c
+++ b/source4/dsdb/samdb/ldb_modules/schema_data.c
@@ -417,12 +417,17 @@ static int schema_data_search(struct ldb_module *module, struct ldb_request *req
 	int ret;
 	struct schema_data_search_data *search_context;
 	struct ldb_request *down_req;
-	struct dsdb_schema *schema = dsdb_get_schema(ldb, NULL);
+	const struct dsdb_schema *schema;
+	if (!ldb_module_get_private(module)) {
+		/* If there is no module data, there is little we can do */
+		return ldb_next_request(module, req);
+	}
 
-	if (!schema || !ldb_module_get_private(module)) {
-		/* If there is no schema, there is little we can do */
+	/* The schema manipulation does not apply to special DNs */
+	if (ldb_dn_is_special(req->op.search.base)) {
 		return ldb_next_request(module, req);
 	}
+
 	for (i=0; i < ARRAY_SIZE(generated_attrs); i++) {
 		if (ldb_attr_in_list(req->op.search.attrs, generated_attrs[i].attr)) {
 			break;
@@ -434,6 +439,12 @@ static int schema_data_search(struct ldb_module *module, struct ldb_request *req
 		return ldb_next_request(module, req);
 	}
 
+	schema = dsdb_get_schema(ldb, NULL);
+	if (!schema || !ldb_module_get_private(module)) {
+		/* If there is no schema, there is little we can do */
+		return ldb_next_request(module, req);
+	}
+
 	search_context = talloc(req, struct schema_data_search_data);
 	if (!search_context) {
 		ldb_oom(ldb);