ACTION_SUBTREE
*action = ACTION_SUBTREE;
*action = ACTION_SUBTREE;
*action = ACTION_SUBTREE;
enum page_walk_action action = ACTION_SUBTREE;
if (err || action != ACTION_SUBTREE)
action = ACTION_SUBTREE;
walk->action = ACTION_SUBTREE;
walk->action = ACTION_SUBTREE;
walk->action = ACTION_SUBTREE;