diff options
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 54 |
1 files changed, 43 insertions, 11 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 149ceb5c94ff..3f7bd7ae7d7a 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -100,6 +100,7 @@ int sysctl_tcp_max_orphans __read_mostly = NR_FILE; #define FLAG_UPDATE_TS_RECENT 0x4000 /* tcp_replace_ts_recent() */ #define FLAG_NO_CHALLENGE_ACK 0x8000 /* do not call tcp_send_challenge_ack() */ #define FLAG_ACK_MAYBE_DELAYED 0x10000 /* Likely a delayed ACK */ +#define FLAG_DSACK_TLP 0x20000 /* DSACK for tail loss probe */ #define FLAG_ACKED (FLAG_DATA_ACKED|FLAG_SYN_ACKED) #define FLAG_NOT_DUP (FLAG_DATA|FLAG_WIN_UPDATE|FLAG_ACKED) @@ -454,11 +455,12 @@ static void tcp_sndbuf_expand(struct sock *sk) */ /* Slow part of check#2. */ -static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb) +static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb, + unsigned int skbtruesize) { struct tcp_sock *tp = tcp_sk(sk); /* Optimize this! */ - int truesize = tcp_win_from_space(sk, skb->truesize) >> 1; + int truesize = tcp_win_from_space(sk, skbtruesize) >> 1; int window = tcp_win_from_space(sk, sock_net(sk)->ipv4.sysctl_tcp_rmem[2]) >> 1; while (tp->rcv_ssthresh <= window) { @@ -471,7 +473,27 @@ static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb) return 0; } -static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb) +/* Even if skb appears to have a bad len/truesize ratio, TCP coalescing + * can play nice with us, as sk_buff and skb->head might be either + * freed or shared with up to MAX_SKB_FRAGS segments. + * Only give a boost to drivers using page frag(s) to hold the frame(s), + * and if no payload was pulled in skb->head before reaching us. + */ +static u32 truesize_adjust(bool adjust, const struct sk_buff *skb) +{ + u32 truesize = skb->truesize; + + if (adjust && !skb_headlen(skb)) { + truesize -= SKB_TRUESIZE(skb_end_offset(skb)); + /* paranoid check, some drivers might be buggy */ + if (unlikely((int)truesize < (int)skb->len)) + truesize = skb->truesize; + } + return truesize; +} + +static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb, + bool adjust) { struct tcp_sock *tp = tcp_sk(sk); int room; @@ -480,15 +502,16 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb) /* Check #1 */ if (room > 0 && !tcp_under_memory_pressure(sk)) { + unsigned int truesize = truesize_adjust(adjust, skb); int incr; /* Check #2. Increase window, if skb with such overhead * will fit to rcvbuf in future. */ - if (tcp_win_from_space(sk, skb->truesize) <= skb->len) + if (tcp_win_from_space(sk, truesize) <= skb->len) incr = 2 * tp->advmss; else - incr = __tcp_grow_window(sk, skb); + incr = __tcp_grow_window(sk, skb, truesize); if (incr) { incr = max_t(int, incr, 2 * skb->len); @@ -782,7 +805,7 @@ static void tcp_event_data_recv(struct sock *sk, struct sk_buff *skb) tcp_ecn_check_ce(sk, skb); if (skb->len >= 128) - tcp_grow_window(sk, skb); + tcp_grow_window(sk, skb, true); } /* Called to compute a smoothed rtt estimate. The data fed to this @@ -969,6 +992,8 @@ static u32 tcp_dsack_seen(struct tcp_sock *tp, u32 start_seq, return 0; if (seq_len > tp->mss_cache) dup_segs = DIV_ROUND_UP(seq_len, tp->mss_cache); + else if (tp->tlp_high_seq && tp->tlp_high_seq == end_seq) + state->flag |= FLAG_DSACK_TLP; tp->dsack_dups += dup_segs; /* Skip the DSACK if dup segs weren't retransmitted by sender */ @@ -976,7 +1001,14 @@ static u32 tcp_dsack_seen(struct tcp_sock *tp, u32 start_seq, return 0; tp->rx_opt.sack_ok |= TCP_DSACK_SEEN; - tp->rack.dsack_seen = 1; + /* We increase the RACK ordering window in rounds where we receive + * DSACKs that may have been due to reordering causing RACK to trigger + * a spurious fast recovery. Thus RACK ignores DSACKs that happen + * without having seen reordering, or that match TLP probes (TLP + * is timer-driven, not triggered by RACK). + */ + if (tp->reord_seen && !(state->flag & FLAG_DSACK_TLP)) + tp->rack.dsack_seen = 1; state->flag |= FLAG_DSACKING_ACK; /* A spurious retransmission is delivered */ @@ -3628,7 +3660,7 @@ static void tcp_process_tlp_ack(struct sock *sk, u32 ack, int flag) if (!tp->tlp_retrans) { /* TLP of new data has been acknowledged */ tp->tlp_high_seq = 0; - } else if (flag & FLAG_DSACKING_ACK) { + } else if (flag & FLAG_DSACK_TLP) { /* This DSACK means original and TLP probe arrived; no loss */ tp->tlp_high_seq = 0; } else if (after(ack, tp->tlp_high_seq)) { @@ -4769,7 +4801,7 @@ coalesce_done: * and trigger fast retransmit. */ if (tcp_is_sack(tp)) - tcp_grow_window(sk, skb); + tcp_grow_window(sk, skb, true); kfree_skb_partial(skb, fragstolen); skb = NULL; goto add_sack; @@ -4857,7 +4889,7 @@ end: * and trigger fast retransmit. */ if (tcp_is_sack(tp)) - tcp_grow_window(sk, skb); + tcp_grow_window(sk, skb, false); skb_condense(skb); skb_set_owner_r(skb, sk); } @@ -5383,7 +5415,7 @@ static void tcp_new_space(struct sock *sk) tp->snd_cwnd_stamp = tcp_jiffies32; } - sk->sk_write_space(sk); + INDIRECT_CALL_1(sk->sk_write_space, sk_stream_write_space, sk); } static void tcp_check_space(struct sock *sk) |