From e5fd91f1ef340da553f7a79da9540c3db711c937 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Tue, 8 Sep 2015 01:01:14 -0300 Subject: Linux-libre 4.2-gnu --- net/ipv4/tcp_output.c | 106 ++++++++++++++++++++++++++------------------------ 1 file changed, 56 insertions(+), 50 deletions(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index d80faa151..bb07d2257 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -50,8 +50,8 @@ int sysctl_tcp_retrans_collapse __read_mostly = 1; */ int sysctl_tcp_workaround_signed_windows __read_mostly = 0; -/* Default TSQ limit of two TSO segments */ -int sysctl_tcp_limit_output_bytes __read_mostly = 131072; +/* Default TSQ limit of four TSO segments */ +int sysctl_tcp_limit_output_bytes __read_mostly = 262144; /* This limits the percentage of the congestion window which we * will allow a single TSO frame to consume. Building TSO frames @@ -350,6 +350,15 @@ static void tcp_ecn_send_syn(struct sock *sk, struct sk_buff *skb) } } +static void tcp_ecn_clear_syn(struct sock *sk, struct sk_buff *skb) +{ + if (sock_net(sk)->ipv4.sysctl_tcp_ecn_fallback) + /* tp->ecn_flags are cleared at a later point in time when + * SYN ACK is ultimatively being received. + */ + TCP_SKB_CB(skb)->tcp_flags &= ~(TCPHDR_ECE | TCPHDR_CWR); +} + static void tcp_ecn_make_synack(const struct request_sock *req, struct tcphdr *th, struct sock *sk) @@ -393,8 +402,6 @@ static void tcp_ecn_send(struct sock *sk, struct sk_buff *skb, */ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags) { - struct skb_shared_info *shinfo = skb_shinfo(skb); - skb->ip_summed = CHECKSUM_PARTIAL; skb->csum = 0; @@ -402,8 +409,6 @@ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags) TCP_SKB_CB(skb)->sacked = 0; tcp_skb_pcount_set(skb, 1); - shinfo->gso_size = 0; - shinfo->gso_type = 0; TCP_SKB_CB(skb)->seq = seq; if (flags & (TCPHDR_SYN | TCPHDR_FIN)) @@ -1001,6 +1006,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, } tcp_options_write((__be32 *)(th + 1), tp, &opts); + skb_shinfo(skb)->gso_type = sk->sk_gso_type; if (likely((tcb->tcp_flags & TCPHDR_SYN) == 0)) tcp_ecn_send(sk, skb, tcp_header_size); @@ -1025,8 +1031,10 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, TCP_ADD_STATS(sock_net(sk), TCP_MIB_OUTSEGS, tcp_skb_pcount(skb)); - /* OK, its time to fill skb_shinfo(skb)->gso_segs */ + tp->segs_out += tcp_skb_pcount(skb); + /* OK, its time to fill skb_shinfo(skb)->gso_{segs|size} */ skb_shinfo(skb)->gso_segs = tcp_skb_pcount(skb); + skb_shinfo(skb)->gso_size = tcp_skb_mss(skb); /* Our usage of tstamp should remain private */ skb->tstamp.tv64 = 0; @@ -1063,25 +1071,17 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb) } /* Initialize TSO segments for a packet. */ -static void tcp_set_skb_tso_segs(const struct sock *sk, struct sk_buff *skb, - unsigned int mss_now) +static void tcp_set_skb_tso_segs(struct sk_buff *skb, unsigned int mss_now) { - struct skb_shared_info *shinfo = skb_shinfo(skb); - - /* Make sure we own this skb before messing gso_size/gso_segs */ - WARN_ON_ONCE(skb_cloned(skb)); - if (skb->len <= mss_now || skb->ip_summed == CHECKSUM_NONE) { /* Avoid the costly divide in the normal * non-TSO case. */ tcp_skb_pcount_set(skb, 1); - shinfo->gso_size = 0; - shinfo->gso_type = 0; + TCP_SKB_CB(skb)->tcp_gso_size = 0; } else { tcp_skb_pcount_set(skb, DIV_ROUND_UP(skb->len, mss_now)); - shinfo->gso_size = mss_now; - shinfo->gso_type = sk->sk_gso_type; + TCP_SKB_CB(skb)->tcp_gso_size = mss_now; } } @@ -1170,7 +1170,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, return -ENOMEM; /* Get a new skb... force flag on. */ - buff = sk_stream_alloc_skb(sk, nsize, gfp); + buff = sk_stream_alloc_skb(sk, nsize, gfp, true); if (!buff) return -ENOMEM; /* We'll just try again later. */ @@ -1213,8 +1213,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, old_factor = tcp_skb_pcount(skb); /* Fix up tso_factor for both original and new SKB. */ - tcp_set_skb_tso_segs(sk, skb, mss_now); - tcp_set_skb_tso_segs(sk, buff, mss_now); + tcp_set_skb_tso_segs(skb, mss_now); + tcp_set_skb_tso_segs(buff, mss_now); /* If this packet has been sent out already, we must * adjust the various packet counters. @@ -1294,7 +1294,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len) /* Any change of skb->len requires recalculation of tso factor. */ if (tcp_skb_pcount(skb) > 1) - tcp_set_skb_tso_segs(sk, skb, tcp_skb_mss(skb)); + tcp_set_skb_tso_segs(skb, tcp_skb_mss(skb)); return 0; } @@ -1626,13 +1626,12 @@ static inline unsigned int tcp_cwnd_test(const struct tcp_sock *tp, * This must be invoked the first time we consider transmitting * SKB onto the wire. */ -static int tcp_init_tso_segs(const struct sock *sk, struct sk_buff *skb, - unsigned int mss_now) +static int tcp_init_tso_segs(struct sk_buff *skb, unsigned int mss_now) { int tso_segs = tcp_skb_pcount(skb); if (!tso_segs || (tso_segs > 1 && tcp_skb_mss(skb) != mss_now)) { - tcp_set_skb_tso_segs(sk, skb, mss_now); + tcp_set_skb_tso_segs(skb, mss_now); tso_segs = tcp_skb_pcount(skb); } return tso_segs; @@ -1687,7 +1686,7 @@ static unsigned int tcp_snd_test(const struct sock *sk, struct sk_buff *skb, const struct tcp_sock *tp = tcp_sk(sk); unsigned int cwnd_quota; - tcp_init_tso_segs(sk, skb, cur_mss); + tcp_init_tso_segs(skb, cur_mss); if (!tcp_nagle_test(tp, skb, cur_mss, nonagle)) return 0; @@ -1729,7 +1728,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len, if (skb->len != skb->data_len) return tcp_fragment(sk, skb, len, mss_now, gfp); - buff = sk_stream_alloc_skb(sk, 0, gfp); + buff = sk_stream_alloc_skb(sk, 0, gfp, true); if (unlikely(!buff)) return -ENOMEM; @@ -1756,8 +1755,8 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len, tcp_fragment_tstamp(skb, buff); /* Fix up tso_factor for both original and new SKB. */ - tcp_set_skb_tso_segs(sk, skb, mss_now); - tcp_set_skb_tso_segs(sk, buff, mss_now); + tcp_set_skb_tso_segs(skb, mss_now); + tcp_set_skb_tso_segs(buff, mss_now); /* Link BUFF into the send queue. */ __skb_header_release(buff); @@ -1948,7 +1947,7 @@ static int tcp_mtu_probe(struct sock *sk) } /* We're allowed to probe. Build it now. */ - nskb = sk_stream_alloc_skb(sk, probe_size, GFP_ATOMIC); + nskb = sk_stream_alloc_skb(sk, probe_size, GFP_ATOMIC, false); if (!nskb) return -1; sk->sk_wmem_queued += nskb->truesize; @@ -1991,7 +1990,7 @@ static int tcp_mtu_probe(struct sock *sk) skb->len, 0); } else { __pskb_trim_head(skb, copy); - tcp_set_skb_tso_segs(sk, skb, mss_now); + tcp_set_skb_tso_segs(skb, mss_now); } TCP_SKB_CB(skb)->seq += copy; } @@ -2001,7 +2000,7 @@ static int tcp_mtu_probe(struct sock *sk) if (len >= probe_size) break; } - tcp_init_tso_segs(sk, nskb, nskb->len); + tcp_init_tso_segs(nskb, nskb->len); /* We're ready to send. If this fails, the probe will * be resegmented into mss-sized pieces by tcp_write_xmit(). @@ -2063,7 +2062,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, while ((skb = tcp_send_head(sk))) { unsigned int limit; - tso_segs = tcp_init_tso_segs(sk, skb, mss_now); + tso_segs = tcp_init_tso_segs(skb, mss_now); BUG_ON(!tso_segs); if (unlikely(tp->repair) && tp->repair_queue == TCP_SEND_QUEUE) { @@ -2085,7 +2084,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now))) break; - if (tso_segs == 1 || !max_segs) { + if (tso_segs == 1) { if (unlikely(!tcp_nagle_test(tp, skb, mss_now, (tcp_skb_is_last(sk, skb) ? nonagle : TCP_NAGLE_PUSH)))) @@ -2098,7 +2097,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, } limit = mss_now; - if (tso_segs > 1 && max_segs && !tcp_urg_mode(tp)) + if (tso_segs > 1 && !tcp_urg_mode(tp)) limit = tcp_mss_split_point(sk, skb, mss_now, min_t(unsigned int, cwnd_quota, @@ -2399,7 +2398,7 @@ u32 __tcp_select_window(struct sock *sk) if (free_space < (full_space >> 1)) { icsk->icsk_ack.quick = 0; - if (sk_under_memory_pressure(sk)) + if (tcp_under_memory_pressure(sk)) tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss); @@ -2617,11 +2616,15 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) if (unlikely(oldpcount > 1)) { if (skb_unclone(skb, GFP_ATOMIC)) return -ENOMEM; - tcp_init_tso_segs(sk, skb, cur_mss); + tcp_init_tso_segs(skb, cur_mss); tcp_adjust_pcount(sk, skb, oldpcount - tcp_skb_pcount(skb)); } } + /* RFC3168, section 6.1.1.1. ECN fallback */ + if ((TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN_ECN) == TCPHDR_SYN_ECN) + tcp_ecn_clear_syn(sk, skb); + tcp_retrans_try_collapse(sk, skb, cur_mss); /* Make a copy, if the first transmission SKB clone we made @@ -2823,8 +2826,10 @@ begin_fwd: * connection tear down and (memory) recovery. * Otherwise tcp_send_fin() could be tempted to either delay FIN * or even be forced to close flow without any FIN. + * In general, we want to allow one skb per socket to avoid hangs + * with edge trigger epoll() */ -static void sk_forced_wmem_schedule(struct sock *sk, int size) +void sk_forced_mem_schedule(struct sock *sk, int size) { int amt, status; @@ -2848,7 +2853,7 @@ void tcp_send_fin(struct sock *sk) * Note: in the latter case, FIN packet will be sent after a timeout, * as TCP stack thinks it has already been transmitted. */ - if (tskb && (tcp_send_head(sk) || sk_under_memory_pressure(sk))) { + if (tskb && (tcp_send_head(sk) || tcp_under_memory_pressure(sk))) { coalesce: TCP_SKB_CB(tskb)->tcp_flags |= TCPHDR_FIN; TCP_SKB_CB(tskb)->end_seq++; @@ -2871,7 +2876,7 @@ coalesce: return; } skb_reserve(skb, MAX_TCP_HEADER); - sk_forced_wmem_schedule(sk, skb->truesize); + sk_forced_mem_schedule(sk, skb->truesize); /* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */ tcp_init_nondata_skb(skb, tp->write_seq, TCPHDR_ACK | TCPHDR_FIN); @@ -3182,7 +3187,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) /* limit to order-0 allocations */ space = min_t(size_t, space, SKB_MAX_HEAD(MAX_TCP_HEADER)); - syn_data = sk_stream_alloc_skb(sk, space, sk->sk_allocation); + syn_data = sk_stream_alloc_skb(sk, space, sk->sk_allocation, false); if (!syn_data) goto fallback; syn_data->ip_summed = CHECKSUM_PARTIAL; @@ -3248,7 +3253,7 @@ int tcp_connect(struct sock *sk) return 0; } - buff = sk_stream_alloc_skb(sk, 0, sk->sk_allocation); + buff = sk_stream_alloc_skb(sk, 0, sk->sk_allocation, true); if (unlikely(!buff)) return -ENOBUFS; @@ -3397,7 +3402,7 @@ EXPORT_SYMBOL_GPL(tcp_send_ack); * one is with SEG.SEQ=SND.UNA to deliver urgent pointer, another is * out-of-date with SND.UNA-1 to probe window. */ -static int tcp_xmit_probe_skb(struct sock *sk, int urgent) +static int tcp_xmit_probe_skb(struct sock *sk, int urgent, int mib) { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *skb; @@ -3415,6 +3420,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent) */ tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPHDR_ACK); skb_mstamp_get(&skb->skb_mstamp); + NET_INC_STATS_BH(sock_net(sk), mib); return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC); } @@ -3422,12 +3428,12 @@ void tcp_send_window_probe(struct sock *sk) { if (sk->sk_state == TCP_ESTABLISHED) { tcp_sk(sk)->snd_wl1 = tcp_sk(sk)->rcv_nxt - 1; - tcp_xmit_probe_skb(sk, 0); + tcp_xmit_probe_skb(sk, 0, LINUX_MIB_TCPWINPROBE); } } /* Initiate keepalive or window probe from timer. */ -int tcp_write_wakeup(struct sock *sk) +int tcp_write_wakeup(struct sock *sk, int mib) { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *skb; @@ -3455,7 +3461,7 @@ int tcp_write_wakeup(struct sock *sk) if (tcp_fragment(sk, skb, seg_size, mss, GFP_ATOMIC)) return -1; } else if (!tcp_skb_pcount(skb)) - tcp_set_skb_tso_segs(sk, skb, mss); + tcp_set_skb_tso_segs(skb, mss); TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH; err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); @@ -3464,8 +3470,8 @@ int tcp_write_wakeup(struct sock *sk) return err; } else { if (between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF)) - tcp_xmit_probe_skb(sk, 1); - return tcp_xmit_probe_skb(sk, 0); + tcp_xmit_probe_skb(sk, 1, mib); + return tcp_xmit_probe_skb(sk, 0, mib); } } @@ -3479,7 +3485,7 @@ void tcp_send_probe0(struct sock *sk) unsigned long probe_max; int err; - err = tcp_write_wakeup(sk); + err = tcp_write_wakeup(sk, LINUX_MIB_TCPWINPROBE); if (tp->packets_out || !tcp_send_head(sk)) { /* Cancel probe timer, if it is not required. */ @@ -3505,7 +3511,7 @@ void tcp_send_probe0(struct sock *sk) probe_max = TCP_RESOURCE_PROBE_INTERVAL; } inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, - inet_csk_rto_backoff(icsk, probe_max), + tcp_probe0_when(sk, probe_max), TCP_RTO_MAX); } -- cgit v1.2.3