Commit 675297c9 authored Oct 16, 2013 by Neal Cardwell Committed by David S. Miller Oct 18, 2013

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>

parent 3ba405db

net/ipv4/tcp_output.c

+0 −15

Original line number	Diff line number	Diff line
		@@ -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.
		*/