Function vm_object_backing_insert_ref

freebsd/vm/vm_object.c:786–804

* Insert an object into a backing_object's shadow list with an additional * reference to the backing_object added. */

 * reference to the backing_object added.
 */
static void
vm_object_backing_insert_ref(vm_object_t object, vm_object_t backing_object)
{

	VM_OBJECT_ASSERT_WLOCKED(object);

	if ((backing_object->flags & OBJ_ANON) != 0) {
		VM_OBJECT_WLOCK(backing_object);
		KASSERT((backing_object->flags & OBJ_DEAD) == 0,
		    ("shadowing dead anonymous object"));
		vm_object_reference_locked(backing_object);
		vm_object_backing_insert_locked(object, backing_object);
		vm_object_clear_flag(backing_object, OBJ_ONEMAPPING);
		VM_OBJECT_WUNLOCK(backing_object);
	} else {
		vm_object_reference(backing_object);
		object->backing_object = backing_object;
	}
}

/*
 * Transfer a backing reference from backing_object to object.