From 6475be16fd9b3c6746ca4d18959246b13c669ea8 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 1 Sep 2005 22:47:01 -0700 Subject: [TCP]: Keep TSO enabled even during loss events. All we need to do is resegment the queue so that we record SACK information accurately. The edges of the SACK blocks guide our resegmenting decisions. With help from Herbert Xu. Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 36 ++++++++++++++++++++++++------------ 1 file changed, 24 insertions(+), 12 deletions(-) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 1afb080bdf0..29222b96495 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -923,14 +923,6 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ int flag = 0; int i; - /* So, SACKs for already sent large segments will be lost. - * Not good, but alternative is to resegment the queue. */ - if (sk->sk_route_caps & NETIF_F_TSO) { - sk->sk_route_caps &= ~NETIF_F_TSO; - sock_set_flag(sk, SOCK_NO_LARGESEND); - tp->mss_cache = tp->mss_cache; - } - if (!tp->sacked_out) tp->fackets_out = 0; prior_fackets = tp->fackets_out; @@ -978,20 +970,40 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ flag |= FLAG_DATA_LOST; sk_stream_for_retrans_queue(skb, sk) { - u8 sacked = TCP_SKB_CB(skb)->sacked; - int in_sack; + int in_sack, pcount; + u8 sacked; /* The retransmission queue is always in order, so * we can short-circuit the walk early. */ - if(!before(TCP_SKB_CB(skb)->seq, end_seq)) + if (!before(TCP_SKB_CB(skb)->seq, end_seq)) break; - fack_count += tcp_skb_pcount(skb); + pcount = tcp_skb_pcount(skb); + + if (pcount > 1 && + (after(start_seq, TCP_SKB_CB(skb)->seq) || + before(end_seq, TCP_SKB_CB(skb)->end_seq))) { + unsigned int pkt_len; + + if (after(start_seq, TCP_SKB_CB(skb)->seq)) + pkt_len = (start_seq - + TCP_SKB_CB(skb)->seq); + else + pkt_len = (end_seq - + TCP_SKB_CB(skb)->seq); + if (tcp_fragment(sk, skb, pkt_len, skb_shinfo(skb)->tso_size)) + break; + pcount = tcp_skb_pcount(skb); + } + + fack_count += pcount; in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq) && !before(end_seq, TCP_SKB_CB(skb)->end_seq); + sacked = TCP_SKB_CB(skb)->sacked; + /* Account D-SACK for retransmitted packet. */ if ((dup_sack && in_sack) && (sacked & TCPCB_RETRANS) && -- cgit v1.2.3