+ r = unit_add_cgroup_from_text(u, name, true, &b);
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ CGroupAttribute *a;
+
+ /* Try to move things to the new place, and clean up the old place */
+ cgroup_bonding_realize(b);
+ cgroup_bonding_migrate(b, u->cgroup_bondings);
+
+ if (old_path)
+ cg_trim(controller, old_path, true);
+
+ /* Apply the attributes to the new group */
+ LIST_FOREACH(by_unit, a, u->cgroup_attributes)
+ if (streq(a->controller, controller))
+ cgroup_attribute_apply(a, b);
+ }
+
+ contents = strjoin("[", UNIT_VTABLE(u)->exec_section, "]\n"
+ "ControlGroup=", name, "\n", NULL);
+ if (!contents)
+ return -ENOMEM;
+
+ return unit_write_drop_in(u, runtime, controller, contents);