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authorJohn Fastabend <john.r.fastabend@intel.com>2010-06-16 14:18:12 +0000
committerDavid S. Miller <davem@davemloft.net>2010-06-23 12:58:41 -0700
commit6afff0caa721211e8c04bdc7627ee3bff95bcb95 (patch)
treeec0b2f5b2e15f847ffad3db9501bbd9661bf671b /net/core
parent1dc8d8c06d4002be4d1373fc06f25cd589be47e1 (diff)
net: consolidate netif_needs_gso() checks
netif_needs_gso() is checked twice in the TX path once, before submitting the skb to the qdisc and once after it is dequeued from the qdisc just before calling ndo_hard_start(). This opens a window for a user to change the gso/tso or tx checksum settings that can cause netif_needs_gso to be true in one check and false in the other. Specifically, changing TX checksum setting may cause the warning in skb_gso_segment() to be triggered if the checksum is calculated earlier. This consolidates the netif_needs_gso() calls so that the stack only checks if gso is needed in dev_hard_start_xmit(). Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c68
1 files changed, 32 insertions, 36 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 5902426ef58..7f390b52caa 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1895,6 +1895,22 @@ static inline void skb_orphan_try(struct sk_buff *skb)
skb_orphan(skb);
}
+/*
+ * Returns true if either:
+ * 1. skb has frag_list and the device doesn't support FRAGLIST, or
+ * 2. skb is fragmented and the device does not support SG, or if
+ * at least one of fragments is in highmem and device does not
+ * support DMA from it.
+ */
+static inline int skb_needs_linearize(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ return skb_is_nonlinear(skb) &&
+ ((skb_has_frags(skb) && !(dev->features & NETIF_F_FRAGLIST)) ||
+ (skb_shinfo(skb)->nr_frags && (!(dev->features & NETIF_F_SG) ||
+ illegal_highdma(dev, skb))));
+}
+
int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
struct netdev_queue *txq)
{
@@ -1919,6 +1935,22 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
goto out_kfree_skb;
if (skb->next)
goto gso;
+ } else {
+ if (skb_needs_linearize(skb, dev) &&
+ __skb_linearize(skb))
+ goto out_kfree_skb;
+
+ /* If packet is not checksummed and device does not
+ * support checksumming for this protocol, complete
+ * checksumming here.
+ */
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ skb_set_transport_header(skb, skb->csum_start -
+ skb_headroom(skb));
+ if (!dev_can_checksum(dev, skb) &&
+ skb_checksum_help(skb))
+ goto out_kfree_skb;
+ }
}
rc = ops->ndo_start_xmit(skb, dev);
@@ -2089,22 +2121,6 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
return rc;
}
-/*
- * Returns true if either:
- * 1. skb has frag_list and the device doesn't support FRAGLIST, or
- * 2. skb is fragmented and the device does not support SG, or if
- * at least one of fragments is in highmem and device does not
- * support DMA from it.
- */
-static inline int skb_needs_linearize(struct sk_buff *skb,
- struct net_device *dev)
-{
- return skb_is_nonlinear(skb) &&
- ((skb_has_frags(skb) && !(dev->features & NETIF_F_FRAGLIST)) ||
- (skb_shinfo(skb)->nr_frags && (!(dev->features & NETIF_F_SG) ||
- illegal_highdma(dev, skb))));
-}
-
/**
* dev_queue_xmit - transmit a buffer
* @skb: buffer to transmit
@@ -2137,25 +2153,6 @@ int dev_queue_xmit(struct sk_buff *skb)
struct Qdisc *q;
int rc = -ENOMEM;
- /* GSO will handle the following emulations directly. */
- if (netif_needs_gso(dev, skb))
- goto gso;
-
- /* Convert a paged skb to linear, if required */
- if (skb_needs_linearize(skb, dev) && __skb_linearize(skb))
- goto out_kfree_skb;
-
- /* If packet is not checksummed and device does not support
- * checksumming for this protocol, complete checksumming here.
- */
- if (skb->ip_summed == CHECKSUM_PARTIAL) {
- skb_set_transport_header(skb, skb->csum_start -
- skb_headroom(skb));
- if (!dev_can_checksum(dev, skb) && skb_checksum_help(skb))
- goto out_kfree_skb;
- }
-
-gso:
/* Disable soft irqs for various locks below. Also
* stops preemption for RCU.
*/
@@ -2214,7 +2211,6 @@ gso:
rc = -ENETDOWN;
rcu_read_unlock_bh();
-out_kfree_skb:
kfree_skb(skb);
return rc;
out: