From 57e1ab6eaddc9f2c358cd4afb497cda6e3c6821a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 16 Nov 2010 20:36:42 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ipv4/igmp.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 50f6bc1a002..e0e77e297de 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -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, -- 2.39.3