diff --git a/libcli/auth/netlogon_creds_cli.c b/libcli/auth/netlogon_creds_cli.c
index 716a565128d..fec192bdae2 100644
--- a/libcli/auth/netlogon_creds_cli.c
+++ b/libcli/auth/netlogon_creds_cli.c
@@ -813,7 +813,8 @@ struct tevent_req *netlogon_creds_cli_lock_send(TALLOC_CTX *mem_ctx,
 	subreq = g_lock_lock_send(state, ev,
 				  context->db.g_ctx,
 				  string_term_tdb_data(context->db.key_name),
-				  G_LOCK_WRITE);
+				  G_LOCK_WRITE,
+				  NULL, NULL);
 	if (tevent_req_nomem(subreq, req)) {
 		return tevent_req_post(req, ev);
 	}
@@ -1027,7 +1028,8 @@ struct tevent_req *netlogon_creds_cli_lck_send(
 	subreq = g_lock_lock_send(state, ev,
 				  context->db.g_ctx,
 				  string_term_tdb_data(context->db.key_name),
-				  gtype);
+				  gtype,
+				  NULL, NULL);
 	if (tevent_req_nomem(subreq, req)) {
 		return tevent_req_post(req, ev);
 	}
diff --git a/source3/include/g_lock.h b/source3/include/g_lock.h
index e3dd1b5c076..c96431346a6 100644
--- a/source3/include/g_lock.h
+++ b/source3/include/g_lock.h
@@ -74,7 +74,9 @@ struct tevent_req *g_lock_lock_send(TALLOC_CTX *mem_ctx,
 				    struct tevent_context *ev,
 				    struct g_lock_ctx *ctx,
 				    TDB_DATA key,
-				    enum g_lock_type type);
+				    enum g_lock_type type,
+				    g_lock_lock_cb_fn_t cb_fn,
+				    void *cb_private);
 NTSTATUS g_lock_lock_recv(struct tevent_req *req);
 NTSTATUS g_lock_lock(struct g_lock_ctx *ctx, TDB_DATA key,
 		     enum g_lock_type lock_type, struct timeval timeout);
diff --git a/source3/lib/g_lock.c b/source3/lib/g_lock.c
index 7868a69a337..a22f9dcad06 100644
--- a/source3/lib/g_lock.c
+++ b/source3/lib/g_lock.c
@@ -990,7 +990,9 @@ struct tevent_req *g_lock_lock_send(TALLOC_CTX *mem_ctx,
 				    struct tevent_context *ev,
 				    struct g_lock_ctx *ctx,
 				    TDB_DATA key,
-				    enum g_lock_type type)
+				    enum g_lock_type type,
+				    g_lock_lock_cb_fn_t cb_fn,
+				    void *cb_private)
 {
 	struct tevent_req *req;
 	struct g_lock_lock_state *state;
@@ -1008,11 +1010,24 @@ struct tevent_req *g_lock_lock_send(TALLOC_CTX *mem_ctx,
 	state->ctx = ctx;
 	state->key = key;
 	state->type = type;
+	state->cb_fn = cb_fn;
+	state->cb_private = cb_private;
 
 	fn_state = (struct g_lock_lock_fn_state) {
 		.req_state = state,
 	};
 
+	/*
+	 * We allow a cn_fn only for G_LOCK_WRITE for now.
+	 *
+	 * It's all we currently need and it makes a few things
+	 * easier to implement.
+	 */
+	if (unlikely(cb_fn != NULL && type != G_LOCK_WRITE)) {
+		tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_6);
+		return tevent_req_post(req, ev);
+	}
+
 	status = dbwrap_do_locked(ctx->db, key, g_lock_lock_fn, &fn_state);
 	if (tevent_req_nterror(req, status)) {
 		DBG_DEBUG("dbwrap_do_locked failed: %s\n",
@@ -1113,6 +1128,9 @@ NTSTATUS g_lock_lock_recv(struct tevent_req *req)
 	NTSTATUS status;
 
 	if (tevent_req_is_nterror(req, &status)) {
+		if (NT_STATUS_EQUAL(status, NT_STATUS_WAS_UNLOCKED)) {
+			return NT_STATUS_OK;
+		}
 		return status;
 	}
 
@@ -1278,7 +1296,7 @@ NTSTATUS g_lock_lock(struct g_lock_ctx *ctx, TDB_DATA key,
 	if (ev == NULL) {
 		goto fail;
 	}
-	req = g_lock_lock_send(frame, ev, ctx, key, type);
+	req = g_lock_lock_send(frame, ev, ctx, key, type, cb_fn, cb_private);
 	if (req == NULL) {
 		goto fail;
 	}
diff --git a/source3/torture/test_g_lock.c b/source3/torture/test_g_lock.c
index 51133393960..57899e9e337 100644
--- a/source3/torture/test_g_lock.c
+++ b/source3/torture/test_g_lock.c
@@ -526,7 +526,7 @@ bool run_g_lock4(int dummy)
 		goto fail;
 	}
 
-	req = g_lock_lock_send(ev, ev, ctx, key, G_LOCK_WRITE);
+	req = g_lock_lock_send(ev, ev, ctx, key, G_LOCK_WRITE, NULL, NULL);
 	if (req == NULL) {
 		fprintf(stderr, "g_lock_lock send failed\n");
 		goto fail;
@@ -657,7 +657,7 @@ bool run_g_lock4a(int dummy)
 		goto fail;
 	}
 
-	req = g_lock_lock_send(ev, ev, ctx, key, G_LOCK_WRITE);
+	req = g_lock_lock_send(ev, ev, ctx, key, G_LOCK_WRITE, NULL, NULL);
 	if (req == NULL) {
 		fprintf(stderr, "g_lock_lock send failed\n");
 		goto fail;
@@ -1135,7 +1135,8 @@ bool run_g_lock7(int dummy)
 			ev,
 			ctx,
 			key,
-			G_LOCK_UPGRADE);
+			G_LOCK_UPGRADE,
+			NULL, NULL);
 		if (req == NULL) {
 			fprintf(stderr, "g_lock_lock_send(UPGRADE) failed\n");
 			exit(1);