From 9f58f3b721f52a4d3f497ea57f830ccd307f1d76 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@helsinki.fi>
Date: Thu, 15 Nov 2007 19:42:54 -0800
Subject: [PATCH] [TCP]: Make lost retrans detection more self-contained
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Highest_sack_end_seq is no longer calculated in the loop,
thus it can be pushed to the worker function altogether
making that function independent of the sacktag.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/tcp_input.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 31294b52ad428..7a2bfd85fff0f 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1115,16 +1115,23 @@ static int tcp_is_sackblock_valid(struct tcp_sock *tp, int is_dsack,
*
* Search retransmitted skbs from write_queue that were sent when snd_nxt was
* less than what is now known to be received by the other end (derived from
- * SACK blocks by the caller). Also calculate the lowest snd_nxt among the
- * remaining retransmitted skbs to avoid some costly processing per ACKs.
+ * highest SACK block). Also calculate the lowest snd_nxt among the remaining
+ * retransmitted skbs to avoid some costly processing per ACKs.
*/
-static int tcp_mark_lost_retrans(struct sock *sk, u32 received_upto)
+static int tcp_mark_lost_retrans(struct sock *sk)
{
+ const struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
int flag = 0;
int cnt = 0;
u32 new_low_seq = tp->snd_nxt;
+ u32 received_upto = TCP_SKB_CB(tp->highest_sack)->end_seq;
+
+ if (!tcp_is_fack(tp) || !tp->retrans_out ||
+ !after(received_upto, tp->lost_retrans_low) ||
+ icsk->icsk_ca_state != TCP_CA_Recovery)
+ return flag;
tcp_for_write_queue(skb, sk) {
u32 ack_seq = TCP_SKB_CB(skb)->ack_seq;
@@ -1245,7 +1252,6 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
int num_sacks = (ptr[1] - TCPOLEN_SACK_BASE)>>3;
int reord = tp->packets_out;
int prior_fackets;
- u32 highest_sack_end_seq;
int flag = 0;
int found_dup_sack = 0;
int cached_fack_count;
@@ -1513,11 +1519,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
flag &= ~FLAG_ONLY_ORIG_SACKED;
}
- highest_sack_end_seq = TCP_SKB_CB(tp->highest_sack)->end_seq;
- if (tcp_is_fack(tp) && tp->retrans_out &&
- after(highest_sack_end_seq, tp->lost_retrans_low) &&
- icsk->icsk_ca_state == TCP_CA_Recovery)
- flag |= tcp_mark_lost_retrans(sk, highest_sack_end_seq);
+ flag |= tcp_mark_lost_retrans(sk);
tcp_verify_left_out(tp);
--
2.30.2