Commit ce93718f authored by David S. Miller's avatar David S. Miller
Browse files

net: Don't keep around original SKB when we software segment GSO frames. 



Just maintain the list properly by returning the head of the remaining
SKB list from dev_hard_start_xmit().

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 50cbe9ab

include/linux/netdevice.h

+2 −2
Original line number Diff line number Diff line
@@ -2828,8 +2828,8 @@ int dev_change_carrier(struct net_device *, bool new_carrier); 
int dev_get_phys_port_id(struct net_device *dev,

			 struct netdev_phys_port_id *ppid);

struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev);

int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,

			struct netdev_queue *txq);

struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,

				    struct netdev_queue *txq, int *ret);

int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb);

int dev_forward_skb(struct net_device *dev, struct sk_buff *skb);

bool is_skb_forwardable(struct net_device *dev, struct sk_buff *skb);

net/core/dev.c

+14 −65
Original line number Diff line number Diff line
@@ -2485,52 +2485,6 @@ static int illegal_highdma(struct net_device *dev, struct sk_buff *skb) 
	return 0;

}



struct dev_gso_cb {

	void (*destructor)(struct sk_buff *skb);

};



#define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)



static void dev_gso_skb_destructor(struct sk_buff *skb)

{

	struct dev_gso_cb *cb;



	kfree_skb_list(skb->next);

	skb->next = NULL;



	cb = DEV_GSO_CB(skb);

	if (cb->destructor)

		cb->destructor(skb);

}



/**

 *	dev_gso_segment - Perform emulated hardware segmentation on skb.

 *	@skb: buffer to segment

 *	@features: device features as applicable to this skb

 *

 *	This function segments the given skb and stores the list of segments

 *	in skb->next.

 */

static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features)

{

	struct sk_buff *segs;



	segs = skb_gso_segment(skb, features);



	/* Verifying header integrity only. */

	if (!segs)

		return 0;



	if (IS_ERR(segs))

		return PTR_ERR(segs);



	skb->next = segs;

	DEV_GSO_CB(skb)->destructor = skb->destructor;

	skb->destructor = dev_gso_skb_destructor;



	return 0;

}



/* If MPLS offload request, verify we are testing hardware MPLS features

 * instead of standard features for the netdev.

 */
@@ -2682,8 +2636,13 @@ struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev) 
		features &= dev->hw_enc_features;



	if (netif_needs_gso(skb, features)) {

		if (unlikely(dev_gso_segment(skb, features)))

			goto out_kfree_skb;

		struct sk_buff *segs;



		segs = skb_gso_segment(skb, features);

		kfree_skb(skb);

		if (IS_ERR(segs))

			segs = NULL;

		skb = segs;

	} else {

		if (skb_needs_linearize(skb, features) &&

		    __skb_linearize(skb))
@@ -2714,26 +2673,16 @@ struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev) 
	return NULL;

}



int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,

			struct netdev_queue *txq)

struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,

				    struct netdev_queue *txq, int *ret)

{

	int rc = NETDEV_TX_OK;



	if (likely(!skb->next))

		return xmit_one(skb, dev, txq, false);



	skb->next = xmit_list(skb->next, dev, txq, &rc);

	if (likely(skb->next == NULL)) {

		skb->destructor = DEV_GSO_CB(skb)->destructor;

		consume_skb(skb);

		return rc;

	if (likely(!skb->next)) {

		*ret = xmit_one(skb, dev, txq, false);

		return skb;

	}



	kfree_skb(skb);



	return rc;

	return xmit_list(skb, dev, txq, ret);

}

EXPORT_SYMBOL_GPL(dev_hard_start_xmit);



static void qdisc_pkt_len_init(struct sk_buff *skb)

{
@@ -2945,7 +2894,7 @@ static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv) 


			if (!netif_xmit_stopped(txq)) {

				__this_cpu_inc(xmit_recursion);

				rc = dev_hard_start_xmit(skb, dev, txq);

				skb = dev_hard_start_xmit(skb, dev, txq, &rc);

				__this_cpu_dec(xmit_recursion);

				if (dev_xmit_complete(rc)) {

					HARD_TX_UNLOCK(dev, txq);

net/sched/sch_generic.c

+1 −1
Original line number Diff line number Diff line
@@ -129,7 +129,7 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, 


	HARD_TX_LOCK(dev, txq, smp_processor_id());

	if (!netif_xmit_frozen_or_stopped(txq))

		ret = dev_hard_start_xmit(skb, dev, txq);

		skb = dev_hard_start_xmit(skb, dev, txq, &ret);



	HARD_TX_UNLOCK(dev, txq);