Commit 926e61b7 authored by Jarek Poplawski's avatar Jarek Poplawski Committed by David S. Miller
Browse files

pkt_sched: Fix tx queue selection in tc_modify_qdisc 



After the recent mq change there is the new select_queue qdisc class
method used in tc_modify_qdisc, but it works OK only for direct child
qdiscs of mq qdisc. Grandchildren always get the first tx queue, which
would give wrong qdisc_root etc. results (e.g. for sch_htb as child of
sch_prio). This patch fixes it by using parent's dev_queue for such
grandchildren qdiscs. The select_queue method's return type is changed
BTW.

With feedback from: Patrick McHardy <kaber@trash.net>

Signed-off-by: default avatarJarek Poplawski <jarkao2@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ca519274

include/net/sch_generic.h

+1 −1
Original line number Diff line number Diff line
@@ -81,7 +81,7 @@ struct Qdisc 
struct Qdisc_class_ops

{

	/* Child qdisc manipulation */

	unsigned int		(*select_queue)(struct Qdisc *, struct tcmsg *);

	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);

	int			(*graft)(struct Qdisc *, unsigned long cl,

					struct Qdisc *, struct Qdisc **);

	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);

net/sched/sch_api.c

+7 −3
Original line number Diff line number Diff line
@@ -1116,12 +1116,16 @@ create_n_graft: 
				 tcm->tcm_parent, tcm->tcm_parent,

				 tca, &err);

	else {

		unsigned int ntx = 0;

		struct netdev_queue *dev_queue;



		if (p && p->ops->cl_ops && p->ops->cl_ops->select_queue)

			ntx = p->ops->cl_ops->select_queue(p, tcm);

			dev_queue = p->ops->cl_ops->select_queue(p, tcm);

		else if (p)

			dev_queue = p->dev_queue;

		else

			dev_queue = netdev_get_tx_queue(dev, 0);



		q = qdisc_create(dev, netdev_get_tx_queue(dev, ntx), p,

		q = qdisc_create(dev, dev_queue, p,

				 tcm->tcm_parent, tcm->tcm_handle,

				 tca, &err);

	}

net/sched/sch_mq.c

+9 −4
Original line number Diff line number Diff line
@@ -125,13 +125,18 @@ static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl) 
	return netdev_get_tx_queue(dev, ntx);

}



static unsigned int mq_select_queue(struct Qdisc *sch, struct tcmsg *tcm)

static struct netdev_queue *mq_select_queue(struct Qdisc *sch,

					    struct tcmsg *tcm)

{

	unsigned int ntx = TC_H_MIN(tcm->tcm_parent);

	struct netdev_queue *dev_queue = mq_queue_get(sch, ntx);



	if (!mq_queue_get(sch, ntx))

		return 0;

	return ntx - 1;

	if (!dev_queue) {

		struct net_device *dev = qdisc_dev(sch);



		return netdev_get_tx_queue(dev, 0);

	}

	return dev_queue;

}



static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,

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