Commit 7f9c33e5 authored Nov 23, 2007 by Ilpo Järvinen Committed by Herbert Xu Nov 23, 2007

[TCP] MTUprobe: Cleanup send queue check (no need to loop)



The original code has striking complexity to perform a query
which can be reduced to a very simple compare.

FIN seqno may be included to write_seq but it should not make
any significant difference here compared to skb->len which was
used previously. One won't end up there with SYN still queued.

Use of write_seq check guarantees that there's a valid skb in
send_head so I removed the extra check.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Acked-by: John Heffner <jheffner@psc.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

parent 91cc17c0

net/ipv4/tcp_output.c

+1 −6

Original line number	Diff line number	Diff line
		@@ -1321,12 +1321,7 @@ static int tcp_mtu_probe(struct sock *sk)
		}

		/* Have enough data in the send queue to probe? */
		len = 0;
		if ((skb = tcp_send_head(sk)) == NULL)
		return -1;
		while ((len += skb->len) < size_needed && !tcp_skb_is_last(sk, skb))
		skb = tcp_write_queue_next(sk, skb);
		if (len < size_needed)
		if (tp->write_seq - tp->snd_nxt < size_needed)
		return -1;

		if (tp->snd_wnd < size_needed)