From a47e5a988a575e64c8c9bae65a1dfe3dca7cba32 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Thu, 15 Nov 2007 19:41:46 -0800 Subject: [PATCH] [TCP]: Convert highest_sack to sk_buff to allow direct access MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It is going to replace the sack fastpath hint quite soon... :-) Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- include/linux/tcp.h | 6 ++++-- include/net/tcp.h | 10 ++++++++++ net/ipv4/tcp_input.c | 12 ++++++------ net/ipv4/tcp_output.c | 19 ++++++++++--------- 4 files changed, 30 insertions(+), 17 deletions(-) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index bac17c59b24..34acee66223 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -332,8 +332,10 @@ struct tcp_sock { struct tcp_sack_block_wire recv_sack_cache[4]; - u32 highest_sack; /* Start seq of globally highest revd SACK - * (validity guaranteed only if sacked_out > 0) */ + struct sk_buff *highest_sack; /* highest skb with SACK received + * (validity guaranteed only if + * sacked_out > 0) + */ /* from STCP, retrans queue hinting */ struct sk_buff* lost_skb_hint; diff --git a/include/net/tcp.h b/include/net/tcp.h index d893b448076..0ede804b16d 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1312,6 +1312,16 @@ static inline int tcp_write_queue_empty(struct sock *sk) return skb_queue_empty(&sk->sk_write_queue); } +/* Start sequence of the highest skb with SACKed bit, valid only if + * sacked > 0 or when the caller has ensured validity by itself. + */ +static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) +{ + if (!tp->sacked_out) + return tp->snd_una; + return TCP_SKB_CB(tp->highest_sack)->seq; +} + /* /proc */ enum tcp_seq_states { TCP_SEQ_STATE_LISTENING, diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index c0e8f2b1fa7..31294b52ad4 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1245,7 +1245,7 @@ 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 = tp->lost_retrans_low; + u32 highest_sack_end_seq; int flag = 0; int found_dup_sack = 0; int cached_fack_count; @@ -1256,7 +1256,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ if (!tp->sacked_out) { if (WARN_ON(tp->fackets_out)) tp->fackets_out = 0; - tp->highest_sack = tp->snd_una; + tp->highest_sack = tcp_write_queue_head(sk); } prior_fackets = tp->fackets_out; @@ -1483,10 +1483,9 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ if (fack_count > tp->fackets_out) tp->fackets_out = fack_count; - if (after(TCP_SKB_CB(skb)->seq, tp->highest_sack)) { - tp->highest_sack = TCP_SKB_CB(skb)->seq; - highest_sack_end_seq = TCP_SKB_CB(skb)->end_seq; - } + if (after(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp))) + tp->highest_sack = skb; + } else { if (dup_sack && (sacked&TCPCB_RETRANS)) reord = min(fack_count, reord); @@ -1514,6 +1513,7 @@ 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) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f4c1eef89af..ce506af5ce0 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -657,13 +657,15 @@ static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned * tweak SACK fastpath hint too as it would overwrite all changes unless * hint is also changed. */ -static void tcp_adjust_fackets_out(struct tcp_sock *tp, struct sk_buff *skb, +static void tcp_adjust_fackets_out(struct sock *sk, struct sk_buff *skb, int decr) { + struct tcp_sock *tp = tcp_sk(sk); + if (!tp->sacked_out || tcp_is_reno(tp)) return; - if (!before(tp->highest_sack, TCP_SKB_CB(skb)->seq)) + if (!before(tcp_highest_sack_seq(tp), TCP_SKB_CB(skb)->seq)) tp->fackets_out -= decr; /* cnt_hint is "off-by-one" compared with fackets_out (see sacktag) */ @@ -712,9 +714,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss TCP_SKB_CB(buff)->end_seq = TCP_SKB_CB(skb)->end_seq; TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq; - if (tcp_is_sack(tp) && tp->sacked_out && - (TCP_SKB_CB(skb)->seq == tp->highest_sack)) - tp->highest_sack = TCP_SKB_CB(buff)->seq; + if (tcp_is_sack(tp) && tp->sacked_out && (skb == tp->highest_sack)) + tp->highest_sack = buff; /* PSH and FIN should only be set in the second packet. */ flags = TCP_SKB_CB(skb)->flags; @@ -772,7 +773,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss tcp_dec_pcount_approx_int(&tp->sacked_out, diff); tcp_verify_left_out(tp); } - tcp_adjust_fackets_out(tp, skb, diff); + tcp_adjust_fackets_out(sk, skb, diff); } /* Link BUFF into the send queue. */ @@ -1712,7 +1713,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m tcp_skb_pcount(next_skb) != 1); if (WARN_ON(tcp_is_sack(tp) && tp->sacked_out && - (TCP_SKB_CB(next_skb)->seq == tp->highest_sack))) + (next_skb == tp->highest_sack))) return; /* Ok. We will be able to collapse the packet. */ @@ -1747,7 +1748,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m if (tcp_is_reno(tp) && tp->sacked_out) tcp_dec_pcount_approx(&tp->sacked_out, next_skb); - tcp_adjust_fackets_out(tp, next_skb, tcp_skb_pcount(next_skb)); + tcp_adjust_fackets_out(sk, next_skb, tcp_skb_pcount(next_skb)); tp->packets_out -= tcp_skb_pcount(next_skb); /* changed transmit queue under us so clear hints */ @@ -2028,7 +2029,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk) break; tp->forward_skb_hint = skb; - if (after(TCP_SKB_CB(skb)->seq, tp->highest_sack)) + if (after(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp))) break; if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)