igmp: refine skb allocations

IGMP allocates MTU sized skbs. This may fail for large MTU (order-2
allocations), so add a fallback to try lower sizes.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-11-16 20:36:42 +00:00 committed by David S. Miller
parent 4c3710afbc
commit 57e1ab6ead

View file

@ -300,6 +300,8 @@ igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
return scount;
}
#define igmp_skb_size(skb) (*(unsigned int *)((skb)->cb))
static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
{
struct sk_buff *skb;
@ -308,9 +310,16 @@ static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
struct igmpv3_report *pig;
struct net *net = dev_net(dev);
skb = alloc_skb(size + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC);
if (skb == NULL)
return NULL;
while (1) {
skb = alloc_skb(size + LL_ALLOCATED_SPACE(dev),
GFP_ATOMIC | __GFP_NOWARN);
if (skb)
break;
size >>= 1;
if (size < 256)
return NULL;
}
igmp_skb_size(skb) = size;
{
struct flowi fl = { .oif = dev->ifindex,
@ -399,7 +408,7 @@ static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
return skb;
}
#define AVAILABLE(skb) ((skb) ? ((skb)->dev ? (skb)->dev->mtu - (skb)->len : \
#define AVAILABLE(skb) ((skb) ? ((skb)->dev ? igmp_skb_size(skb) - (skb)->len : \
skb_tailroom(skb)) : 0)
static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,