offloading: Make scatter/gather more tolerant of vlans.
When checking if it is necessary to linearize a packet, we currently
use vlan_features if the packet contains either an in-band or out-
of-band vlan tag. However, in-band tags aren't special in any way
for scatter/gather since they are part of the packet buffer and are
simply more data to DMA. Therefore, only use vlan_features for out-
of-band tags, which could potentially have some interaction with
scatter/gather.
Signed-off-by: Jesse Gross <jesse@nicira.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 5968c82..0b403d5 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1976,15 +1976,20 @@
static inline int skb_needs_linearize(struct sk_buff *skb,
struct net_device *dev)
{
- int features = dev->features;
+ if (skb_is_nonlinear(skb)) {
+ int features = dev->features;
- if (skb->protocol == htons(ETH_P_8021Q) || vlan_tx_tag_present(skb))
- features &= dev->vlan_features;
+ if (vlan_tx_tag_present(skb))
+ features &= dev->vlan_features;
- return skb_is_nonlinear(skb) &&
- ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
- (skb_shinfo(skb)->nr_frags && (!(features & NETIF_F_SG) ||
- illegal_highdma(dev, skb))));
+ return (skb_has_frag_list(skb) &&
+ !(features & NETIF_F_FRAGLIST)) ||
+ (skb_shinfo(skb)->nr_frags &&
+ (!(features & NETIF_F_SG) ||
+ illegal_highdma(dev, skb)));
+ }
+
+ return 0;
}
int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,