s4-dsdb: cope with out of sync replication attributes in partition module

if the @ATTRIBUTES or other objects which are replicated between
partions become out of sync, then the ldb would fail to open. This
changes ensures that we can always fix those records, by running the
operation in the top level partition, and replicating the result to
the other partitions

Pair-Programmed-With: Amitay Isaacs <amitay@gmail.com>

Autobuild-User: Andrew Tridgell <tridge@samba.org>
Autobuild-Date: Mon Sep 19 04:31:48 CEST 2011 on sn-devel-104

1 files changed, 68 insertions, 1 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/partition.c b/source4/dsdb/samdb/ldb_modules/partition.c
index b2865487d2..93f2d6be07 100644
--- a/source4/dsdb/samdb/ldb_modules/partition.c
+++ b/source4/dsdb/samdb/ldb_modules/partition.c
@@ -398,6 +398,73 @@ static int partition_send_all(struct ldb_module *module,
 	return partition_call_first(ac);
 }
 
+
+/**
+ * send an operation to the top partition, then copy the resulting
+ * object to all other partitions
+ */
+static int partition_copy_all(struct ldb_module *module,
+			      struct partition_context *ac,
+			      struct ldb_request *req,
+			      struct ldb_dn *dn)
+{
+	unsigned int i;
+	struct partition_private_data *data = talloc_get_type(ldb_module_get_private(module),
+							      struct partition_private_data);
+	int ret, search_ret;
+	struct ldb_result *res;
+
+	/* do the request on the top level sam.ldb synchronously */
+	ret = ldb_next_request(module, req);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	ret = ldb_wait(req->handle, LDB_WAIT_ALL);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	/* now fetch the resulting object, and then copy it to all the
+	 * other partitions. We need this approach to cope with the
+	 * partitions getting out of sync. If for example the
+	 * @ATTRIBUTES object exists on one partition but not the
+	 * others then just doing each of the partitions in turn will
+	 * lead to an error
+	 */
+	search_ret = dsdb_module_search_dn(module, ac, &res, dn, NULL, DSDB_FLAG_NEXT_MODULE, req);
+	if (search_ret != LDB_SUCCESS && ret != LDB_ERR_NO_SUCH_OBJECT) {
+		return search_ret;
+	}
+
+	/* now delete the object in the other partitions. Once that is
+	   done we will re-add the object, if search_ret was not
+	   LDB_ERR_NO_SUCH_OBJECT
+	*/
+	for (i=0; data->partitions && data->partitions[i]; i++) {
+		int pret;
+		pret = dsdb_module_del(data->partitions[i]->module, dn, DSDB_FLAG_NEXT_MODULE, req);
+		if (pret != LDB_SUCCESS && pret != LDB_ERR_NO_SUCH_OBJECT) {
+			/* we should only get success or no
+			   such object from the other partitions */
+			return pret;
+		}
+	}
+
+
+	if (search_ret != LDB_ERR_NO_SUCH_OBJECT) {
+		/* now re-add in the other partitions */
+		for (i=0; data->partitions && data->partitions[i]; i++) {
+			int pret;
+			pret = dsdb_module_add(data->partitions[i]->module, res->msgs[0], DSDB_FLAG_NEXT_MODULE, req);
+			if (pret != LDB_SUCCESS) {
+				return pret;
+			}
+		}
+	}
+
+	return ldb_module_done(req, NULL, NULL, LDB_SUCCESS);
+}
+
 /**
  * Figure out which backend a request needs to be aimed at.  Some
  * requests must be replicated to all backends
@@ -427,7 +494,7 @@ static int partition_replicate(struct ldb_module *module, struct ldb_request *re
 					return ldb_operr(ldb_module_get_ctx(module));
 				}
 				
-				return partition_send_all(module, ac, req);
+				return partition_copy_all(module, ac, req, dn);
 			}
 		}
 	}