if (r < 0)
return r;
- if (u->load_state != UNIT_NOT_FOUND ||
+ /* Check if the unit already exists or is already referenced,
+ * in a number of different ways. Note that to cater for unit
+ * types such as slice, we are generally fine with units that
+ * are marked UNIT_LOADED even even though nothing was
+ * actually loaded, as those unit types don't require a file
+ * on disk to validly load. */
+
+ if (!IN_SET(u->load_state, UNIT_NOT_FOUND, UNIT_LOADED) ||
+ u->fragment_path ||
+ u->source_path ||
+ !strv_isempty(u->dropin_paths) ||
+ u->refs ||
set_size(u->dependencies[UNIT_REFERENCED_BY]) > 0)
return sd_bus_error_setf(error, BUS_ERROR_UNIT_EXISTS, "Unit %s already exists.", name);