From 9580bf2edb402b3afaf9c5a4efb6953f993ef52e Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 30 Apr 2016 10:19:29 -0700 Subject: net: relax expensive skb_unclone() in iptunnel_handle_offloads() Locally generated TCP GSO packets having to go through a GRE/SIT/IPIP tunnel have to go through an expensive skb_unclone() Reallocating skb->head is a lot of work. Test should really check if a 'real clone' of the packet was done. TCP does not care if the original gso_type is changed while the packet travels in the stack. This adds skb_header_unclone() which is a variant of skb_clone() using skb_header_cloned() check instead of skb_cloned(). This variant can probably be used from other points. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/skbuff.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index c84a5a1078c5..c413c588a24f 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1325,6 +1325,16 @@ static inline int skb_header_cloned(const struct sk_buff *skb) return dataref != 1; } +static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri) +{ + might_sleep_if(gfpflags_allow_blocking(pri)); + + if (skb_header_cloned(skb)) + return pskb_expand_head(skb, 0, 0, pri); + + return 0; +} + /** * skb_header_release - release reference to header * @skb: buffer to operate on -- cgit v1.2.3