Commit 160d5e10 authored by Jarek Poplawski's avatar Jarek Poplawski Committed by David S. Miller
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[NET_SCHED] sch_htb: turn intermediate classes into leaves 



- turn intermediate classes into leaves again when their
  last child is deleted (struct htb_class changed)

Signed-off-by: default avatarJarek Poplawski <jarkao2@o2.pl>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a37ef2e3

net/sched/sch_htb.c

+51 −0
Original line number Diff line number Diff line
@@ -147,6 +147,10 @@ struct htb_class { 
	psched_tdiff_t mbuffer;	/* max wait time */

	long tokens, ctokens;	/* current number of tokens */

	psched_time_t t_c;	/* checkpoint time */



	int prio;		/* For parent to leaf return possible here */

	int quantum;		/* we do backup. Finally full replacement  */

				/* of un.leaf originals should be done. */

};



/* TODO: maybe compute rate when size is too large .. or drop ? */
@@ -1271,6 +1275,38 @@ static void htb_destroy_filters(struct tcf_proto **fl) 
	}

}



static inline int htb_parent_last_child(struct htb_class *cl)

{

	if (!cl->parent)

		/* the root class */

		return 0;



	if (!(cl->parent->children.next == &cl->sibling &&

		cl->parent->children.prev == &cl->sibling))

		/* not the last child */

		return 0;



	return 1;

}



static void htb_parent_to_leaf(struct htb_class *cl, struct Qdisc *new_q)

{

	struct htb_class *parent = cl->parent;



	BUG_TRAP(!cl->level && cl->un.leaf.q && !cl->prio_activity);



	parent->level = 0;

	memset(&parent->un.inner, 0, sizeof(parent->un.inner));

	INIT_LIST_HEAD(&parent->un.leaf.drop_list);

	parent->un.leaf.q = new_q ? new_q : &noop_qdisc;

	parent->un.leaf.quantum = parent->quantum;

	parent->un.leaf.prio = parent->prio;

	parent->tokens = parent->buffer;

	parent->ctokens = parent->cbuffer;

	PSCHED_GET_TIME(parent->t_c);

	parent->cmode = HTB_CAN_SEND;

}



static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)

{

	struct htb_sched *q = qdisc_priv(sch);
@@ -1328,6 +1364,8 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg) 
	struct htb_sched *q = qdisc_priv(sch);

	struct htb_class *cl = (struct htb_class *)arg;

	unsigned int qlen;

	struct Qdisc *new_q = NULL;

	int last_child = 0;



	// TODO: why don't allow to delete subtree ? references ? does

	// tc subsys quarantee us that in htb_destroy it holds no class
@@ -1335,6 +1373,12 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg) 
	if (!list_empty(&cl->children) || cl->filter_cnt)

		return -EBUSY;



	if (!cl->level && htb_parent_last_child(cl)) {

		new_q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,

						cl->parent->classid);

		last_child = 1;

	}



	sch_tree_lock(sch);



	/* delete from hash and active; remainder in destroy_class */
@@ -1349,6 +1393,9 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg) 
	if (cl->prio_activity)

		htb_deactivate(q, cl);



	if (last_child)

		htb_parent_to_leaf(cl, new_q);



	if (--cl->refcnt == 0)

		htb_destroy_class(sch, cl);
@@ -1483,6 +1530,10 @@ static int htb_change_class(struct Qdisc *sch, u32 classid, 
			cl->un.leaf.quantum = hopt->quantum;

		if ((cl->un.leaf.prio = hopt->prio) >= TC_HTB_NUMPRIO)

			cl->un.leaf.prio = TC_HTB_NUMPRIO - 1;



		/* backup for htb_parent_to_leaf */

		cl->quantum = cl->un.leaf.quantum;

		cl->prio = cl->un.leaf.prio;

	}



	cl->buffer = hopt->buffer;