From 2996d31f9f292cce67cd9105dc0a4a5ee43d2f14 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Wed, 2 May 2012 18:18:42 +0000 Subject: net: Stop decapitating clones that have a head_frag This change is meant ot prevent stealing the skb->head to use as a page in the event that the skb->head was cloned. This allows the other clones to track each other via shinfo->dataref. Without this we break down to two methods for tracking the reference count, one being dataref, the other being the page count. As a result it becomes difficult to track how many references there are to skb->head. Signed-off-by: Alexander Duyck Cc: Eric Dumazet Cc: Jeff Kirsher Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 2f696ef13dcd..c6f78e2b590f 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4589,7 +4589,7 @@ copyfrags: to->data_len += len; goto merge; } - if (from->head_frag) { + if (from->head_frag && !skb_cloned(from)) { struct page *page; unsigned int offset; @@ -4599,12 +4599,7 @@ copyfrags: offset = from->data - (unsigned char *)page_address(page); skb_fill_page_desc(to, skb_shinfo(to)->nr_frags, page, offset, skb_headlen(from)); - - if (skb_cloned(from)) - get_page(page); - else - *fragstolen = true; - + *fragstolen = true; delta = len; /* we dont know real truesize... */ goto copyfrags; } -- cgit v1.2.3