static int search_rbtree(const struct osl_object *obj,
const struct osl_table *t, unsigned col_num,
struct rb_node **result, struct rb_node ***rb_link)
static int search_rbtree(const struct osl_object *obj,
const struct osl_table *t, unsigned col_num,
struct rb_node **result, struct rb_node ***rb_link)