tcp: remove redundant code in __tcp_retransmit_skb()

Remove the specialized code in __tcp_retransmit_skb() that tries to trim
any ACKed payload preceding a FIN before we retransmit (this was added
in 1999 in v2.2.3pre3). This trimming code was made unreachable by the
more general code added above it that uses tcp_trim_head() to trim any
ACKed payload, with or without a FIN (this was added in "[NET]: Add
segmentation offload support to TCP." in 2002 circa v2.5.33).

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e5ce0e1..ce7c4d9 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2351,21 +2351,6 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 
        tcp_retrans_try_collapse(sk, skb, cur_mss);
 
-       /* Some Solaris stacks overoptimize and ignore the FIN on a
-        * retransmit when old data is attached.  So strip it off
-        * since it is cheap to do so and saves bytes on the network.
-        */
-       if (skb->len > 0 &&
-           (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) &&
-           tp->snd_una == (TCP_SKB_CB(skb)->end_seq - 1)) {
-               if (!pskb_trim(skb, 0)) {
-                       /* Reuse, even though it does some unnecessary work */
-                       tcp_init_nondata_skb(skb, TCP_SKB_CB(skb)->end_seq - 1,
-                                            TCP_SKB_CB(skb)->tcp_flags);
-                       skb->ip_summed = CHECKSUM_NONE;
-               }
-       }
-
        /* Make a copy, if the first transmission SKB clone we made
         * is still in somebody's hands, else make a clone.
         */