[PATCH net] gro: fix aggregation for skb using frag_list

* [PATCH net] gro: fix aggregation for skb using frag_list
@ 2014-09-29 17:34 Eric Dumazet
  2014-09-29 19:19 ` David Miller
  0 siblings, 1 reply; 3+ messages in thread
From: Eric Dumazet @ 2014-09-29 17:34 UTC (permalink / raw)
  To: David Miller; +Cc: netdev, Erez Shitrit

From: Eric Dumazet <edumazet@google.com>

In commit 8a29111c7ca6 ("net: gro: allow to build full sized skb")
I added a regression for linear skb that traditionally force GRO
to use the frag_list fallback.

Erez Shitrit found that at most two segments were aggregated and
the "if (skb_gro_len(p) != pinfo->gso_size)" test was failing.

This is because pinfo at this spot still points to the last skb in the
chain, instead of the first one, where we find the correct gso_size
information.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 8a29111c7ca6 ("net: gro: allow to build full sized skb")
Reported-by: Erez Shitrit <erezsh@mellanox.com>
---
 net/core/skbuff.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index da1378a3e2c7..8d289697cc7a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3152,6 +3152,9 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
 		NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
 		goto done;
 	}
+	/* switch back to head shinfo */
+	pinfo = skb_shinfo(p);
+
 	if (pinfo->frag_list)
 		goto merge;
 	if (skb_gro_len(p) != pinfo->gso_size)

^ permalink raw reply related	[flat|nested] 3+ messages in thread