dbus-unit: always load the unit before handling a message for it

We need to be able to show the properties even of inactive units.
systemctl loads the unit before getting its properties, but this is racy
as the garbage collector may kick in right after the loading.

Fix it by always loading the unit before handling a message for it.

https://bugzilla.redhat.com/show_bug.cgi?id=814966#c6

1 files changed, 10 insertions, 13 deletions

diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index b8d661698b..834fbd7693 100644
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -558,12 +558,15 @@ static DBusHandlerResult bus_unit_message_handler(DBusConnection *connection, DB
         Manager *m = data;
         Unit *u;
         int r;
-        DBusMessage *reply;
+        DBusMessage *reply = NULL;
+        DBusError error;
 
         assert(connection);
         assert(message);
         assert(m);
 
+        dbus_error_init(&error);
+
         if (streq(dbus_message_get_path(message), "/org/freedesktop/systemd1/unit")) {
                 /* Be nice to gdbus and return introspection data for our mid-level paths */
 
@@ -638,20 +641,12 @@ static DBusHandlerResult bus_unit_message_handler(DBusConnection *connection, DB
                 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
         }
 
-        if ((r = manager_get_unit_from_dbus_path(m, dbus_message_get_path(message), &u)) < 0) {
-
+        r = manager_load_unit_from_dbus_path(m, dbus_message_get_path(message), &error, &u);
+        if (r < 0) {
                 if (r == -ENOMEM)
-                        return DBUS_HANDLER_RESULT_NEED_MEMORY;
-
-                if (r == -ENOENT) {
-                        DBusError e;
-
-                        dbus_error_init(&e);
-                        dbus_set_error_const(&e, DBUS_ERROR_UNKNOWN_OBJECT, "Unknown unit");
-                        return bus_send_error_reply(connection, message, &e, r);
-                }
+                        goto oom;
 
-                return bus_send_error_reply(connection, message, NULL, r);
+                return bus_send_error_reply(connection, message, &error, r);
         }
 
         return bus_unit_message_dispatch(u, connection, message);
@@ -660,6 +655,8 @@ oom:
         if (reply)
                 dbus_message_unref(reply);
 
+        dbus_error_free(&error);
+
         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 }