repl_meta_data: Allow delete of an object with dangling backlinks

This should not happen, but stopping all replication because of it is a pain.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13095

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>

Autobuild-User(master): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(master): Fri Nov 24 19:53:50 CET 2017 on sn-devel-144

1 files changed, 36 insertions, 8 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/repl_meta_data.c b/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
index 597e49c50f1..198ac84c730 100644
--- a/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
+++ b/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
@@ -3172,9 +3172,22 @@ static int replmd_modify_handle_linked_attribs(struct ldb_module *module,
 			continue;
 		}
 		if ((schema_attr->linkID & 1) == 1) {
-			if (parent && ldb_request_get_control(parent, DSDB_CONTROL_DBCHECK)) {
-				continue;
+			if (parent) {
+				struct ldb_control *ctrl;
+
+				ctrl = ldb_request_get_control(parent,
+						DSDB_CONTROL_REPLMD_VANISH_LINKS);
+				if (ctrl != NULL) {
+					ctrl->critical = false;
+					continue;
+				}
+				ctrl = ldb_request_get_control(parent,
+						DSDB_CONTROL_DBCHECK);
+				if (ctrl != NULL) {
+					continue;
+				}
 			}
+
 			/* Odd is for the target.  Illegal to modify */
 			ldb_asprintf_errstring(ldb,
 					       "attribute %s must not be modified directly, it is a linked attribute", el->name);
@@ -4275,6 +4288,7 @@ static int replmd_delete_internals(struct ldb_module *module, struct ldb_request
 				/* don't remove the rDN */
 				continue;
 			}
+
 			if (sa->linkID & 1) {
 				/*
 				  we have a backlink in this object
@@ -4288,7 +4302,16 @@ static int replmd_delete_internals(struct ldb_module *module, struct ldb_request
 								replmd_private,
 								old_dn, &guid,
 								el, sa, req);
-				if (ret != LDB_SUCCESS) {
+				if (ret == LDB_SUCCESS) {
+					/*
+					 * now we continue, which means we
+					 * won't remove this backlink
+					 * directly
+					 */
+					continue;
+				}
+
+				if (ret != LDB_ERR_NO_SUCH_ATTRIBUTE) {
 					const char *old_dn_str
 						= ldb_dn_get_linearized(old_dn);
 					ldb_asprintf_errstring(ldb,
@@ -4301,11 +4324,16 @@ static int replmd_delete_internals(struct ldb_module *module, struct ldb_request
 					talloc_free(tmp_ctx);
 					return LDB_ERR_OPERATIONS_ERROR;
 				}
-				/* now we continue, which means we
-				   won't remove this backlink
-				   directly
-				*/
-				continue;
+
+				/*
+				 * Otherwise vanish the link, we are
+				 * out of sync and the controlling
+				 * object does not have the source
+				 * link any more
+				 */
+
+				dsdb_flags |= DSDB_REPLMD_VANISH_LINKS;
+
 			} else if (sa->linkID == 0) {
 				if (ldb_attr_in_list(preserved_attrs, el->name)) {
 					continue;