From 797108d134a91afca9fa59c572336b279bc66afb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Wed, 1 Apr 2009 23:15:17 +0000 Subject: [PATCH] tcp: add helper for counter tweaking due mid-wq change MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We need full-scale adjustment to fix a TCP miscount in the next patch, so just move it into a helper and call for that from the other places. Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- include/net/tcp.h | 15 ---------- net/ipv4/tcp_output.c | 66 ++++++++++++++++++++++--------------------- 2 files changed, 34 insertions(+), 47 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index e54c76d75495..1b94b9bfe2dc 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -616,21 +616,6 @@ static inline int tcp_skb_mss(const struct sk_buff *skb) return skb_shinfo(skb)->gso_size; } -static inline void tcp_dec_pcount_approx_int(__u32 *count, const int decr) -{ - if (*count) { - *count -= decr; - if ((int)*count < 0) - *count = 0; - } -} - -static inline void tcp_dec_pcount_approx(__u32 *count, - const struct sk_buff *skb) -{ - tcp_dec_pcount_approx_int(count, tcp_skb_pcount(skb)); -} - /* Events passed to congestion control interface */ enum tcp_ca_event { CA_EVENT_TX_START, /* first transmit when no packets in flight */ diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index c1f259d2d33b..f1db89bb3aa7 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -754,6 +754,36 @@ static void tcp_adjust_fackets_out(struct sock *sk, struct sk_buff *skb, tp->fackets_out -= decr; } +/* Pcount in the middle of the write queue got changed, we need to do various + * tweaks to fix counters + */ +static void tcp_adjust_pcount(struct sock *sk, struct sk_buff *skb, int decr) +{ + struct tcp_sock *tp = tcp_sk(sk); + + tp->packets_out -= decr; + + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) + tp->sacked_out -= decr; + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) + tp->retrans_out -= decr; + if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) + tp->lost_out -= decr; + + /* Reno case is special. Sigh... */ + if (tcp_is_reno(tp) && decr > 0) + tp->sacked_out -= min_t(u32, tp->sacked_out, decr); + + tcp_adjust_fackets_out(sk, skb, decr); + + if (tp->lost_skb_hint && + before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(tp->lost_skb_hint)->seq) && + (tcp_is_fack(tp) || TCP_SKB_CB(skb)->sacked)) + tp->lost_cnt_hint -= decr; + + tcp_verify_left_out(tp); +} + /* Function to create two new TCP segments. Shrinks the given segment * to the specified size and appends a new segment with the rest of the * packet to the list. This won't be called frequently, I hope. @@ -836,28 +866,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, int diff = old_factor - tcp_skb_pcount(skb) - tcp_skb_pcount(buff); - tp->packets_out -= diff; - - if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED) - tp->sacked_out -= diff; - if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) - tp->retrans_out -= diff; - - if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) - tp->lost_out -= diff; - - /* Adjust Reno SACK estimate. */ - if (tcp_is_reno(tp) && diff > 0) { - tcp_dec_pcount_approx_int(&tp->sacked_out, diff); - tcp_verify_left_out(tp); - } - tcp_adjust_fackets_out(sk, skb, diff); - - if (tp->lost_skb_hint && - before(TCP_SKB_CB(skb)->seq, - TCP_SKB_CB(tp->lost_skb_hint)->seq) && - (tcp_is_fack(tp) || TCP_SKB_CB(skb)->sacked)) - tp->lost_cnt_hint -= diff; + if (diff) + tcp_adjust_pcount(sk, skb, diff); } /* Link BUFF into the send queue. */ @@ -1768,22 +1778,14 @@ static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb) * packet counting does not break. */ TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked & TCPCB_EVER_RETRANS; - if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_RETRANS) - tp->retrans_out -= tcp_skb_pcount(next_skb); - if (TCP_SKB_CB(next_skb)->sacked & TCPCB_LOST) - tp->lost_out -= tcp_skb_pcount(next_skb); - /* Reno case is special. Sigh... */ - if (tcp_is_reno(tp) && tp->sacked_out) - tcp_dec_pcount_approx(&tp->sacked_out, 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 */ tcp_clear_retrans_hints_partial(tp); if (next_skb == tp->retransmit_skb_hint) tp->retransmit_skb_hint = skb; + tcp_adjust_pcount(sk, next_skb, tcp_skb_pcount(next_skb)); + sk_wmem_free_skb(sk, next_skb); }