Commit 99194cff authored by David S. Miller's avatar David S. Miller
Browse files

pkt_sched: Add multiqueue handling to qdisc_graft(). 



Move the destruction of the old queue into qdisc_graft().

When operating on a root qdisc (ie. "parent == NULL"), apply
the operation to all queues.  The caller has grabbed a single
implicit reference for this graft, therefore when we apply the
change to more than one queue we must grab additional qdisc
references.

Otherwise, we are operating on a class of a specific parent qdisc, and
therefore no multiqueue handling is necessary.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 83874000

net/sched/sch_api.c

+59 −42
Original line number Diff line number Diff line
@@ -435,28 +435,22 @@ static u32 qdisc_alloc_handle(struct net_device *dev) 
	return i>0 ? autohandle : 0;

}



/* Attach toplevel qdisc to device dev */

/* Attach toplevel qdisc to device queue. */



static struct Qdisc *

dev_graft_qdisc(struct net_device *dev, struct Qdisc *qdisc)

static struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,

				     struct Qdisc *qdisc)

{

	struct netdev_queue *dev_queue;

	spinlock_t *root_lock;

	struct Qdisc *oqdisc;

	int ingress;



	if (dev->flags & IFF_UP)

		dev_deactivate(dev);



	ingress = 0;

	if (qdisc && qdisc->flags&TCQ_F_INGRESS)

		ingress = 1;



	if (ingress) {

		dev_queue = &dev->rx_queue;

		oqdisc = dev_queue->qdisc;

	} else {

		dev_queue = netdev_get_tx_queue(dev, 0);

		oqdisc = dev_queue->qdisc_sleeping;

	}
@@ -487,9 +481,6 @@ dev_graft_qdisc(struct net_device *dev, struct Qdisc *qdisc) 


	spin_unlock_bh(root_lock);



	if (dev->flags & IFF_UP)

		dev_activate(dev);



	return oqdisc;

}
@@ -521,26 +512,66 @@ void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n) 
}

EXPORT_SYMBOL(qdisc_tree_decrease_qlen);



/* Graft qdisc "new" to class "classid" of qdisc "parent" or

   to device "dev".

static void notify_and_destroy(struct sk_buff *skb, struct nlmsghdr *n, u32 clid,

			       struct Qdisc *old, struct Qdisc *new)

{

	if (new || old)

		qdisc_notify(skb, n, clid, old, new);



   Old qdisc is not destroyed but returned in *old.

	if (old) {

		spin_lock_bh(&old->q.lock);

		qdisc_destroy(old);

		spin_unlock_bh(&old->q.lock);

	}

}



/* Graft qdisc "new" to class "classid" of qdisc "parent" or

 * to device "dev".

 *

 * When appropriate send a netlink notification using 'skb'

 * and "n".

 *

 * On success, destroy old qdisc.

 */



static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,

		       u32 classid,

		       struct Qdisc *new, struct Qdisc **old)

		       struct sk_buff *skb, struct nlmsghdr *n, u32 classid,

		       struct Qdisc *new, struct Qdisc *old)

{

	struct Qdisc *q = old;

	int err = 0;

	struct Qdisc *q = *old;





	if (parent == NULL) {

		unsigned int i, num_q, ingress;



		ingress = 0;

		num_q = dev->num_tx_queues;

		if (q && q->flags & TCQ_F_INGRESS) {

			*old = dev_graft_qdisc(dev, q);

			num_q = 1;

			ingress = 1;

		}



		if (dev->flags & IFF_UP)

			dev_deactivate(dev);



		for (i = 0; i < num_q; i++) {

			struct netdev_queue *dev_queue = &dev->rx_queue;



			if (!ingress)

				dev_queue = netdev_get_tx_queue(dev, i);



			if (ingress) {

				old = dev_graft_qdisc(dev_queue, q);

			} else {

			*old = dev_graft_qdisc(dev, new);

				old = dev_graft_qdisc(dev_queue, new);

				if (new && i > 0)

					atomic_inc(&new->refcnt);

			}

			notify_and_destroy(skb, n, classid, old, new);

		}



		if (dev->flags & IFF_UP)

			dev_activate(dev);

	} else {

		const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
@@ -549,10 +580,12 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent, 
		if (cops) {

			unsigned long cl = cops->get(parent, classid);

			if (cl) {

				err = cops->graft(parent, cl, new, old);

				err = cops->graft(parent, cl, new, &old);

				cops->put(parent, cl);

			}

		}

		if (!err)

			notify_and_destroy(skb, n, classid, old, new);

	}

	return err;

}
@@ -773,16 +806,8 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg) 
			return -EINVAL;

		if (q->handle == 0)

			return -ENOENT;

		if ((err = qdisc_graft(dev, p, clid, NULL, &q)) != 0)

		if ((err = qdisc_graft(dev, p, skb, n, clid, NULL, q)) != 0)

			return err;

		if (q) {

			spinlock_t *root_lock = qdisc_root_lock(q);



			qdisc_notify(skb, n, clid, q, NULL);

			spin_unlock_bh(root_lock);

			qdisc_destroy(q);

			spin_unlock_bh(root_lock);

		}

	} else {

		qdisc_notify(skb, n, clid, NULL, q);

	}
@@ -923,10 +948,9 @@ create_n_graft: 


graft:

	if (1) {

		struct Qdisc *old_q = NULL;

		spinlock_t *root_lock;



		err = qdisc_graft(dev, p, clid, q, &old_q);

		err = qdisc_graft(dev, p, skb, n, clid, q, NULL);

		if (err) {

			if (q) {

				root_lock = qdisc_root_lock(q);
@@ -936,13 +960,6 @@ graft: 
			}

			return err;

		}

		qdisc_notify(skb, n, clid, old_q, q);

		if (old_q) {

			root_lock = qdisc_root_lock(old_q);

			spin_lock_bh(root_lock);

			qdisc_destroy(old_q);

			spin_unlock_bh(root_lock);

		}

	}

	return 0;

}

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