replmd: Mark link conflicts as inactive correctly

The previous patch to handle link conflicts was simply overriding the
received information and marking the link as deleted. We should be doing
this as a separate operation to make it clear what has happened, and so
that the new (i.e. inactive) link details get replicated out.

This patch changes it so that when a conflict occurs, we immediately
overwrite the received information to mark it as deleted, and to update
the version/USN/timestamp/originating_invocation_id to make it clear
that this is a new change.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13055

Signed-off-by: Tim Beale <timbeale@catalyst.net.nz>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/dsdb/samdb/ldb_modules/repl_meta_data.c b/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
index d37137bf0cd172854615836c0f30945a243df7b8..4f347938e17fdc9f7b8c733b74019aeae4f63804 100644 (file)
--- a/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
+++ b/source4/dsdb/samdb/ldb_modules/repl_meta_data.c
@@ -7302,6 +7302,7 @@ static int replmd_process_linked_attribute(struct ldb_module *module,
        enum deletion_state deletion_state = OBJECT_NOT_DELETED;
        struct dsdb_dn *old_dsdb_dn = NULL;
        struct ldb_val *val_to_update = NULL;
+       bool add_as_inactive = false;
 
        /*
         * get the attribute being modified, the search result for the source object,
@@ -7438,8 +7439,11 @@ static int replmd_process_linked_attribute(struct ldb_module *module,
                                    ldb_dn_get_linearized(conflict_pdn->dsdb_dn->dn),
                                    ldb_dn_get_linearized(dsdb_dn->dn));
 
-                       /* don't add the link as active */
-                       active = false;
+                       /*
+                        * we want to keep our existing active link and add the
+                        * received link as inactive
+                        */
+                       add_as_inactive = true;
                }
        }
 
@@ -7516,8 +7520,22 @@ static int replmd_process_linked_attribute(struct ldb_module *module,
                return ret;
        }
 
-       /* if the new link is active, then add the new backlink */
-       if (active) {
+       if (add_as_inactive) {
+
+               /* Set the new link as inactive/deleted to avoid conflicts */
+               ret = replmd_delete_link_value(module, replmd_private, old_el,
+                                              msg->dn, schema, attr, seq_num,
+                                              false, &guid, dsdb_dn,
+                                              val_to_update);
+
+               if (ret != LDB_SUCCESS) {
+                       talloc_free(tmp_ctx);
+                       return ret;
+               }
+
+       } else if (active) {
+
+               /* if the new link is active, then add the new backlink */
                ret = replmd_add_backlink(module, replmd_private,
                                          schema,
                                          msg->dn,