s4:dsdb Reload partition metadata if the main db updates

This uses the fact that the primary DB does not change often.  Before
each operation, we see if the sequence number has changed.

Andrew Bartlett

source4/dsdb/samdb/ldb_modules/partition.c

@@ -412,6 +412,11 @@ static int partition_replicate(struct ldb_module *module, struct ldb_request *re
 	if (!data || !data->partitions) {
 		return ldb_next_request(module, req);
 	}
+
+	ret = partition_reload_if_required(module, data);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
 	
 	if (req->operation != LDB_SEARCH) {
 		/* Is this a special DN, we need to replicate to every backend? */
@@ -463,6 +468,7 @@ static int partition_replicate(struct ldb_module *module, struct ldb_request *re
 /* search */
 static int partition_search(struct ldb_module *module, struct ldb_request *req)
 {
+	int ret;
 	struct ldb_control **saved_controls;
 	/* Find backend */
 	struct partition_private_data *data = talloc_get_type(module->private_data, 
@@ -479,6 +485,11 @@ static int partition_search(struct ldb_module *module, struct ldb_request *req)
 	struct ldb_search_options_control *search_options = NULL;
 	struct dsdb_partition *p;
 	
+	ret = partition_reload_if_required(module, data);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
 	p = find_partition(data, NULL, req);
 	if (p != NULL) {
 		/* the caller specified what partition they want the
@@ -511,7 +522,7 @@ static int partition_search(struct ldb_module *module, struct ldb_request *req)
 	*/
 	
 	if (search_options && (search_options->search_options & LDB_SEARCH_OPTION_PHANTOM_ROOT)) {
-		int ret, i;
+		int i;
 		struct partition_context *ac;
 		if ((search_options->search_options & ~LDB_SEARCH_OPTION_PHANTOM_ROOT) == 0) {
 			/* We have processed this flag, so we are done with this control now */
@@ -615,6 +626,7 @@ static int partition_delete(struct ldb_module *module, struct ldb_request *req)
 /* rename */
 static int partition_rename(struct ldb_module *module, struct ldb_request *req)
 {
+	int ret;
 	/* Find backend */
 	struct dsdb_partition *backend, *backend2;
 	
@@ -626,6 +638,11 @@ static int partition_rename(struct ldb_module *module, struct ldb_request *req)
 		return LDB_ERR_OPERATIONS_ERROR;
 	}
 
+	ret = partition_reload_if_required(module, data);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
 	backend = find_partition(data, req->op.rename.olddn, req);
 	backend2 = find_partition(data, req->op.rename.newdn, req);
 
@@ -751,6 +768,61 @@ static int partition_del_trans(struct ldb_module *module)
 	return final_ret;
 }
 
+int partition_primary_sequence_number(struct ldb_module *module, TALLOC_CTX *mem_ctx, 
+				     enum ldb_sequence_type type, uint64_t *seq_number) 
+{
+	int ret;
+	struct ldb_result *res;
+	struct ldb_seqnum_request *tseq;
+	struct ldb_request *treq;
+	struct ldb_seqnum_result *seqr;
+	res = talloc_zero(mem_ctx, struct ldb_result);
+	if (res == NULL) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	tseq = talloc_zero(res, struct ldb_seqnum_request);
+	if (tseq == NULL) {
+		talloc_free(res);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	tseq->type = type;
+	
+	ret = ldb_build_extended_req(&treq, ldb_module_get_ctx(module), res,
+				     LDB_EXTENDED_SEQUENCE_NUMBER,
+				     tseq,
+				     NULL,
+				     res,
+				     ldb_extended_default_callback,
+				     NULL);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(res);
+		return ret;
+	}
+	
+	ret = ldb_next_request(module, treq);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(res);
+		return ret;
+	}
+	ret = ldb_wait(treq->handle, LDB_WAIT_ALL);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(res);
+		return ret;
+	}
+	
+	seqr = talloc_get_type(res->extended->data,
+			       struct ldb_seqnum_result);
+	if (seqr->flags & LDB_SEQ_TIMESTAMP_SEQUENCE) {
+		ret = LDB_ERR_OPERATIONS_ERROR;
+		ldb_set_errstring(ldb_module_get_ctx(module), "Primary backend in partitions module returned a timestamp based seq number (must return a normal number)");
+		talloc_free(res);
+		return ret;
+	} else {
+		*seq_number = seqr->seq_num;
+	}
+	talloc_free(res);
+	return LDB_SUCCESS;
+}
 
 /* FIXME: This function is still semi-async */
 static int partition_sequence_number(struct ldb_module *module, struct ldb_request *req)
@@ -783,49 +855,12 @@ static int partition_sequence_number(struct ldb_module *module, struct ldb_reque
 	switch (seq->type) {
 	case LDB_SEQ_NEXT:
 	case LDB_SEQ_HIGHEST_SEQ:
-		res = talloc_zero(req, struct ldb_result);
-		if (res == NULL) {
-			return LDB_ERR_OPERATIONS_ERROR;
-		}
-		tseq = talloc_zero(res, struct ldb_seqnum_request);
-		if (tseq == NULL) {
-			talloc_free(res);
-			return LDB_ERR_OPERATIONS_ERROR;
-		}
-		tseq->type = seq->type;
 
-		ret = ldb_build_extended_req(&treq, ldb_module_get_ctx(module), res,
+		ret = partition_primary_sequence_number(module, req, seq->type, &seq_number);
-					     LDB_EXTENDED_SEQUENCE_NUMBER,
-					     tseq,
-					     NULL,
-					     res,
-					     ldb_extended_default_callback,
-					     NULL);
 		if (ret != LDB_SUCCESS) {
-			talloc_free(res);
 			return ret;
 		}
 
-		ret = ldb_next_request(module, treq);
-		if (ret != LDB_SUCCESS) {
-			talloc_free(res);
-			return ret;
-		}
-		ret = ldb_wait(treq->handle, LDB_WAIT_ALL);
-		if (ret != LDB_SUCCESS) {
-			talloc_free(res);
-			return ret;
-		}
-
-		seqr = talloc_get_type(res->extended->data,
-					struct ldb_seqnum_result);
-		if (seqr->flags & LDB_SEQ_TIMESTAMP_SEQUENCE) {
-			timestamp_sequence = seqr->seq_num;
-		} else {
-			seq_number += seqr->seq_num;
-		}
-		talloc_free(res);
-
 		/* Skip the lot if 'data' isn't here yet (initialisation) */
 		for (i=0; data && data->partitions && data->partitions[i]; i++) {
 
@@ -1078,12 +1113,18 @@ static int partition_extended(struct ldb_module *module, struct ldb_request *req
 {
 	struct partition_private_data *data;
 	struct partition_context *ac;
+	int ret;
 
 	data = talloc_get_type(module->private_data, struct partition_private_data);
 	if (!data) {
 		return ldb_next_request(module, req);
 	}
 
+	ret = partition_reload_if_required(module, data);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	
 	if (strcmp(req->op.extended.oid, LDB_EXTENDED_SEQUENCE_NUMBER) == 0) {
 		return partition_sequence_number(module, req);
 	}

source4/dsdb/samdb/ldb_modules/partition.h

@@ -42,6 +42,8 @@ struct partition_private_data {
 	
 	struct partition_module **modules;
 	const char *ldapBackend;
+
+	uint64_t metadata_seq;
 };
 
 #define PARTITION_FIND_OP_NOERROR(module, op) do { \

source4/dsdb/samdb/ldb_modules/partition_init.c

@@ -159,6 +159,38 @@ static int partition_reload_metadata(struct ldb_module *module, struct partition
 	return LDB_SUCCESS;
 }
 
+int partition_reload_if_required(struct ldb_module *module, 
+				 struct partition_private_data *data)
+	
+{
+	uint64_t seq;
+	int ret;
+	TALLOC_CTX *mem_ctx = talloc_new(data);
+	if (!data) {
+		/* Not initilised yet */
+		return LDB_SUCCESS;
+	}
+	if (!mem_ctx) {
+		ldb_oom(ldb_module_get_ctx(module));
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	ret = partition_primary_sequence_number(module, mem_ctx, LDB_SEQ_HIGHEST_SEQ, &seq);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(mem_ctx);
+		return ret;
+	}
+	if (seq != data->metadata_seq) {
+		ret = partition_reload_metadata(module, data, mem_ctx, NULL);
+		if (ret != LDB_SUCCESS) {
+			talloc_free(mem_ctx);
+			return ret;
+		}
+		data->metadata_seq = seq;
+	}
+	talloc_free(mem_ctx);
+	return LDB_SUCCESS;
+}
+
 static const char **find_modules_for_dn(struct partition_private_data *data, struct ldb_dn *dn) 
 {
 	int i;
@@ -577,6 +609,12 @@ int partition_init(struct ldb_module *module)
 		return LDB_ERR_OPERATIONS_ERROR;
 	}
 
+	ret = partition_primary_sequence_number(module, mem_ctx, LDB_SEQ_HIGHEST_SEQ, &data->metadata_seq);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(mem_ctx);
+		return ret;
+	}
+
 	ret = partition_reload_metadata(module, data, mem_ctx, &msg);
 	if (ret != LDB_SUCCESS) {
 		return ret;