[TCP]: Re-place highest_sack check to a more robust position
I previously added checking to position that is rather poor as
state has already been adjusted quite a bit. Re-placing it above
all state changes should be more robust though the return should
never ever get executed regardless of its place :-).
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index cbb83ac..94c8011 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1718,6 +1718,10 @@
BUG_ON(tcp_skb_pcount(skb) != 1 ||
tcp_skb_pcount(next_skb) != 1);
+ if (WARN_ON(tp->sacked_out &&
+ (TCP_SKB_CB(next_skb)->seq == tp->highest_sack)))
+ return;
+
/* Ok. We will be able to collapse the packet. */
tcp_unlink_write_queue(next_skb, sk);
@@ -1734,10 +1738,6 @@
/* Update sequence range on original skb. */
TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;
- if (WARN_ON(tp->sacked_out &&
- (TCP_SKB_CB(next_skb)->seq == tp->highest_sack)))
- return;
-
/* Merge over control information. */
flags |= TCP_SKB_CB(next_skb)->flags; /* This moves PSH/FIN etc. over */
TCP_SKB_CB(skb)->flags = flags;