Unbind_tcf

The unbind_tcf function is used to remove an instance of a filter attached to a class. The cbq_unbind_filter function in net/sched/sch_cbq.c is an example for the unbind_tcf function on a class.

static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg)
{
    struct cbq_class *cl = (struct cbq_class*)arg;

    cl->filters--;
}

This portion of the code clearly indicates that the unbind_tcf function is similar to the put function on a class. The count of the number of filters attached to the class is decremented. For a class to be deleted, this count must be zero.