ldb: Add read_lock and read_unlock to ldb_module_ops

This will be used to implement read locking in ldb_tdb

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Stefan Metzmacher <metze@samba.org>

3 files changed, 52 insertions, 0 deletions

diff --git a/lib/ldb/ABI/ldb-1.1.31.sigs b/lib/ldb/ABI/ldb-1.1.31.sigs
index d183708b215..1be2ae73a2f 100644
--- a/lib/ldb/ABI/ldb-1.1.31.sigs
+++ b/lib/ldb/ABI/ldb-1.1.31.sigs
@@ -186,6 +186,8 @@ ldb_next_del_trans: int (struct ldb_module *)
 ldb_next_end_trans: int (struct ldb_module *)
 ldb_next_init: int (struct ldb_module *)
 ldb_next_prepare_commit: int (struct ldb_module *)
+ldb_next_read_lock: int (struct ldb_module *)
+ldb_next_read_unlock: int (struct ldb_module *)
 ldb_next_remote_request: int (struct ldb_module *, struct ldb_request *)
 ldb_next_request: int (struct ldb_module *, struct ldb_request *)
 ldb_next_start_trans: int (struct ldb_module *)
diff --git a/lib/ldb/common/ldb_modules.c b/lib/ldb/common/ldb_modules.c
index ca93299ab00..3dd0438c128 100644
--- a/lib/ldb/common/ldb_modules.c
+++ b/lib/ldb/common/ldb_modules.c
@@ -641,6 +641,52 @@ int ldb_next_end_trans(struct ldb_module *module)
 	return ret;
 }
 
+int ldb_next_read_lock(struct ldb_module *module)
+{
+	int ret;
+	FIND_OP(module, read_lock);
+	ret = module->ops->read_lock(module);
+	if (ret == LDB_SUCCESS) {
+		return ret;
+	}
+	if (!ldb_errstring(module->ldb)) {
+		/* Set a default error string, to place the blame somewhere */
+		ldb_asprintf_errstring(module->ldb,
+				       "read_lock error in module %s: %s (%d)",
+				       module->ops->name, ldb_strerror(ret),
+				       ret);
+	}
+	if ((module && module->ldb->flags & LDB_FLG_ENABLE_TRACING)) {
+		ldb_debug(module->ldb, LDB_DEBUG_TRACE,
+			  "ldb_next_read_lock error: %s",
+			  ldb_errstring(module->ldb));
+	}
+	return ret;
+}
+
+int ldb_next_read_unlock(struct ldb_module *module)
+{
+	int ret;
+	FIND_OP(module, read_unlock);
+	ret = module->ops->read_unlock(module);
+	if (ret == LDB_SUCCESS) {
+		return ret;
+	}
+	if (!ldb_errstring(module->ldb)) {
+		/* Set a default error string, to place the blame somewhere */
+		ldb_asprintf_errstring(module->ldb,
+				       "read_unlock error in module %s: %s (%d)",
+				       module->ops->name, ldb_strerror(ret),
+				       ret);
+	}
+	if ((module && module->ldb->flags & LDB_FLG_ENABLE_TRACING)) {
+		ldb_debug(module->ldb, LDB_DEBUG_TRACE,
+			  "ldb_next_read_unlock error: %s",
+			  ldb_errstring(module->ldb));
+	}
+	return ret;
+}
+
 int ldb_next_prepare_commit(struct ldb_module *module)
 {
 	int ret;
diff --git a/lib/ldb/include/ldb_module.h b/lib/ldb/include/ldb_module.h
index 3d56e68eddd..0f5feeb084c 100644
--- a/lib/ldb/include/ldb_module.h
+++ b/lib/ldb/include/ldb_module.h
@@ -77,6 +77,8 @@ struct ldb_module_ops {
 	int (*end_transaction)(struct ldb_module *);
 	int (*del_transaction)(struct ldb_module *);
 	int (*sequence_number)(struct ldb_module *, struct ldb_request *);
+	int (*read_lock)(struct ldb_module *);
+	int (*read_unlock)(struct ldb_module *);
 	void *private_data;
 };
 
@@ -203,6 +205,8 @@ int ldb_next_end_trans(struct ldb_module *module);
 int ldb_next_del_trans(struct ldb_module *module);
 int ldb_next_prepare_commit(struct ldb_module *module);
 int ldb_next_init(struct ldb_module *module);
+int ldb_next_read_lock(struct ldb_module *module);
+int ldb_next_read_unlock(struct ldb_module *module);
 
 void ldb_set_errstring(struct ldb_context *ldb, const char *err_string);
 void ldb_asprintf_errstring(struct ldb_context *ldb, const char *format, ...) PRINTF_ATTRIBUTE(2,3);