s4-dsdb: don't cache the NTDS settings DN

this DN can change due to a server rename, so we cannot cache it. It
is set by provision, but not anywhere else.

This seems to not have a large performance impact

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

1 files changed, 8 insertions, 9 deletions

diff --git a/source4/dsdb/common/util.c b/source4/dsdb/common/util.c
index f306748d08..3b287e3635 100644
--- a/source4/dsdb/common/util.c
+++ b/source4/dsdb/common/util.c
@@ -1252,9 +1252,9 @@ bool samdb_set_ntds_settings_dn(struct ldb_context *ldb, struct ldb_dn *ntds_set
 	struct ldb_dn *ntds_settings_dn_new;
 	struct ldb_dn *ntds_settings_dn_old;
 
-	/* see if we have a cached copy */
+	/* see if we have a forced copy from provision */
 	ntds_settings_dn_old = talloc_get_type(ldb_get_opaque(ldb, 
-							      "cache.ntds_settings_dn"), struct ldb_dn);
+							      "forced.ntds_settings_dn"), struct ldb_dn);
 
 	tmp_ctx = talloc_new(ldb);
 	if (tmp_ctx == NULL) {
@@ -1266,8 +1266,8 @@ bool samdb_set_ntds_settings_dn(struct ldb_context *ldb, struct ldb_dn *ntds_set
 		goto failed;
 	}
 
-	/* cache the domain_sid in the ldb */
-	if (ldb_set_opaque(ldb, "cache.ntds_settings_dn", ntds_settings_dn_new) != LDB_SUCCESS) {
+	/* set the DN in the ldb to avoid lookups during provision */
+	if (ldb_set_opaque(ldb, "forced.ntds_settings_dn", ntds_settings_dn_new) != LDB_SUCCESS) {
 		goto failed;
 	}
 
@@ -1295,7 +1295,7 @@ struct ldb_dn *samdb_ntds_settings_dn(struct ldb_context *ldb)
 	struct ldb_dn *settings_dn;
 
 	/* see if we have a cached copy */
-	settings_dn = (struct ldb_dn *)ldb_get_opaque(ldb, "cache.ntds_settings_dn");
+	settings_dn = (struct ldb_dn *)ldb_get_opaque(ldb, "forced.ntds_settings_dn");
 	if (settings_dn) {
 		return settings_dn;
 	}
@@ -1318,10 +1318,9 @@ struct ldb_dn *samdb_ntds_settings_dn(struct ldb_context *ldb)
 
 	settings_dn = ldb_msg_find_attr_as_dn(ldb, tmp_ctx, root_res->msgs[0], "dsServiceName");
 
-	/* cache the domain_sid in the ldb */
-	if (ldb_set_opaque(ldb, "cache.ntds_settings_dn", settings_dn) != LDB_SUCCESS) {
-		goto failed;
-	}
+	/* note that we do not cache the DN here, as that would mean
+	 * we could not handle server renames at runtime. Only
+	 * provision sets up forced.ntds_settings_dn */
 
 	talloc_steal(ldb, settings_dn);
 	talloc_free(tmp_ctx);