s4-ldb: fixed nested searches inside ldb modules

We need to keep a search count in ltdb to allow for nesting
of searches inside a module

Signed-off-by: Andrew Tridgell <tridge@samba.org>

2 files changed, 12 insertions, 4 deletions

diff --git a/source4/lib/ldb/ldb_tdb/ldb_tdb.c b/source4/lib/ldb/ldb_tdb/ldb_tdb.c
index 7fb3cdc067..48409f2cba 100644
--- a/source4/lib/ldb/ldb_tdb/ldb_tdb.c
+++ b/source4/lib/ldb/ldb_tdb/ldb_tdb.c
@@ -88,10 +88,16 @@ int ltdb_lock_read(struct ldb_module *module)
 {
 	void *data = ldb_module_get_private(module);
 	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
-	if (ltdb->in_transaction == 0) {
-		return tdb_lockall_read(ltdb->tdb);
+	int ret = 0;
+
+	if (ltdb->in_transaction == 0 &&
+	    ltdb->read_lock_count == 0) {
+		ret = tdb_lockall_read(ltdb->tdb);
 	}
-	return 0;
+	if (ret == 0) {
+		ltdb->read_lock_count++;
+	}
+	return ret;
 }
 
 /*
@@ -101,9 +107,10 @@ int ltdb_unlock_read(struct ldb_module *module)
 {
 	void *data = ldb_module_get_private(module);
 	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
-	if (ltdb->in_transaction == 0) {
+	if (ltdb->in_transaction == 0 && ltdb->read_lock_count == 1) {
 		return tdb_unlockall_read(ltdb->tdb);
 	}
+	ltdb->read_lock_count--;
 	return 0;
 }
 
diff --git a/source4/lib/ldb/ldb_tdb/ldb_tdb.h b/source4/lib/ldb/ldb_tdb/ldb_tdb.h
index 0f17c82eaa..bb4cb3f8b5 100644
--- a/source4/lib/ldb/ldb_tdb/ldb_tdb.h
+++ b/source4/lib/ldb/ldb_tdb/ldb_tdb.h
@@ -31,6 +31,7 @@ struct ltdb_private {
 	bool check_base;
 	struct ltdb_idxptr *idxptr;
 	bool prepared_commit;
+	int read_lock_count;
 };
 
 /*