From ce93718fb7cdbc064c3000ff59e4d3200bdfa744 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sat, 30 Aug 2014 19:22:20 -0700 Subject: [PATCH] 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: David S. Miller --- include/linux/netdevice.h | 4 +- net/core/dev.c | 79 +++++++-------------------------------- net/sched/sch_generic.c | 2 +- 3 files changed, 17 insertions(+), 68 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 47c49ba2dcf4..202c25a9aadf 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -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); diff --git a/net/core/dev.c b/net/core/dev.c index 75bc5b068a13..c89da4f306b1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -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 @@ out_null: 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); diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index f178798a5836..a8bf9f9928bd 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -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); -- 2.20.1