objectclass_attrs: Remove schema copy shallow from attr_handler2

This appears quite expensive (particularly in provision), and also
unnecessary.

Signed-off-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

Autobuild-User(master): Andreas Schneider <asn@cryptomilk.org>
Autobuild-Date(master): Fri Mar 10 15:34:39 CET 2017 on sn-devel-144

2 files changed, 15 insertions, 21 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/objectclass_attrs.c b/source4/dsdb/samdb/ldb_modules/objectclass_attrs.c
index e239fb946e7..c144578f227 100644
--- a/source4/dsdb/samdb/ldb_modules/objectclass_attrs.c
+++ b/source4/dsdb/samdb/ldb_modules/objectclass_attrs.c
@@ -456,25 +456,13 @@ static int attr_handler2(struct oc_context *ac)
 		struct dsdb_attribute *att = talloc(ac, struct dsdb_attribute);
 		const struct dsdb_syntax *attrSyntax;
 		WERROR status;
-		struct dsdb_schema *tmp_schema = NULL;
 
-		/*
-		 * We temporary remove the prefix map from the schema,
-		 * a new prefix map is added by dsdb_create_prefix_mapping()
-		 * via the "schema_data" module.
-		 */
-		tmp_schema = dsdb_schema_copy_shallow(ac, ldb, ac->schema);
-		if (tmp_schema == NULL) {
-			return ldb_module_oom(ac->module);
-		}
-		TALLOC_FREE(tmp_schema->prefixmap);
-		status= dsdb_attribute_from_ldb(tmp_schema, msg, att);
+		status = dsdb_attribute_from_ldb(NULL, msg, att);
 		if (!W_ERROR_IS_OK(status)) {
 			ldb_set_errstring(ldb,
 						"objectclass: failed to translate the schemaAttribute to a dsdb_attribute");
 			return LDB_ERR_UNWILLING_TO_PERFORM;
 		}
-		TALLOC_FREE(tmp_schema);
 
 		attrSyntax = dsdb_syntax_for_attribute(att);
 		if (!attrSyntax) {
diff --git a/source4/dsdb/schema/schema_init.c b/source4/dsdb/schema/schema_init.c
index 199ee28053c..256c4677452 100644
--- a/source4/dsdb/schema/schema_init.c
+++ b/source4/dsdb/schema/schema_init.c
@@ -621,9 +621,15 @@ static int dsdb_schema_setup_ldb_schema_attribute(struct ldb_context *ldb,
 } while (0)
 
 /** Create an dsdb_attribute out of ldb message, attr must be already talloced
+ *
+ * If supplied the attribute will be checked against the prefixmap to
+ * ensure it can be mapped.  However we can't have this attribute
+ * const as dsdb_schema_pfm_attid_from_oid calls
+ * dsdb_schema_pfm_make_attid_impl() which may modify prefixmap in
+ * other situations.
  */
 
-WERROR dsdb_attribute_from_ldb(const struct dsdb_schema *schema,
+WERROR dsdb_attribute_from_ldb(struct dsdb_schema_prefixmap *prefixmap,
 			       struct ldb_message *msg,
 			       struct dsdb_attribute *attr)
 {
@@ -646,13 +652,13 @@ WERROR dsdb_attribute_from_ldb(const struct dsdb_schema *schema,
 
 	GET_STRING_LDB(msg, "lDAPDisplayName", attr, attr, lDAPDisplayName, true);
 	GET_STRING_LDB(msg, "attributeID", attr, attr, attributeID_oid, true);
-	if (!schema->prefixmap || schema->prefixmap->length == 0) {
+	if (!prefixmap || prefixmap->length == 0) {
 		/* set an invalid value */
 		attr->attributeID_id = DRSUAPI_ATTID_INVALID;
 	} else {
-		status = dsdb_schema_pfm_attid_from_oid(schema->prefixmap,
-						    attr->attributeID_oid,
-						    &attr->attributeID_id);
+		status = dsdb_schema_pfm_attid_from_oid(prefixmap,
+							attr->attributeID_oid,
+							&attr->attributeID_id);
 		if (!W_ERROR_IS_OK(status)) {
 			DEBUG(0,("%s: '%s': unable to map attributeID %s: %s\n",
 				__location__, attr->lDAPDisplayName, attr->attributeID_oid,
@@ -676,11 +682,11 @@ WERROR dsdb_attribute_from_ldb(const struct dsdb_schema *schema,
 	GET_UINT32_LDB(msg, "linkID", attr, linkID);
 
 	GET_STRING_LDB(msg, "attributeSyntax", attr, attr, attributeSyntax_oid, true);
-	if (!schema->prefixmap || schema->prefixmap->length == 0) {
+	if (!prefixmap || prefixmap->length == 0) {
 		/* set an invalid value */
 		attr->attributeSyntax_id = DRSUAPI_ATTID_INVALID;
 	} else {
-		status = dsdb_schema_pfm_attid_from_oid(schema->prefixmap,
+		status = dsdb_schema_pfm_attid_from_oid(prefixmap,
 							attr->attributeSyntax_oid,
 							&attr->attributeSyntax_id);
 		if (!W_ERROR_IS_OK(status)) {
@@ -723,7 +729,7 @@ WERROR dsdb_set_attribute_from_ldb_dups(struct ldb_context *ldb,
 		return WERR_NOT_ENOUGH_MEMORY;
 	}
 
-	status = dsdb_attribute_from_ldb(schema, msg, attr);
+	status = dsdb_attribute_from_ldb(schema->prefixmap, msg, attr);
 	if (!W_ERROR_IS_OK(status)) {
 		return status;
 	}