diff options
| -rw-r--r-- | net/ipv4/tcp_input.c | 51 |
1 files changed, 31 insertions, 20 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 0640453fce54..d764b5854dfc 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4764,8 +4764,8 @@ static void tcp_ofo_queue(struct sock *sk) } } -static bool tcp_prune_ofo_queue(struct sock *sk); -static int tcp_prune_queue(struct sock *sk); +static bool tcp_prune_ofo_queue(struct sock *sk, const struct sk_buff *in_skb); +static int tcp_prune_queue(struct sock *sk, const struct sk_buff *in_skb); static int tcp_try_rmem_schedule(struct sock *sk, struct sk_buff *skb, unsigned int size) @@ -4773,11 +4773,11 @@ static int tcp_try_rmem_schedule(struct sock *sk, struct sk_buff *skb, if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || !sk_rmem_schedule(sk, skb, size)) { - if (tcp_prune_queue(sk) < 0) + if (tcp_prune_queue(sk, skb) < 0) return -1; while (!sk_rmem_schedule(sk, skb, size)) { - if (!tcp_prune_ofo_queue(sk)) + if (!tcp_prune_ofo_queue(sk, skb)) return -1; } } @@ -5329,6 +5329,8 @@ new_range: * Clean the out-of-order queue to make room. * We drop high sequences packets to : * 1) Let a chance for holes to be filled. + * This means we do not drop packets from ooo queue if their sequence + * is before incoming packet sequence. * 2) not add too big latencies if thousands of packets sit there. * (But if application shrinks SO_RCVBUF, we could still end up * freeing whole queue here) @@ -5336,24 +5338,31 @@ new_range: * * Return true if queue has shrunk. */ -static bool tcp_prune_ofo_queue(struct sock *sk) +static bool tcp_prune_ofo_queue(struct sock *sk, const struct sk_buff *in_skb) { struct tcp_sock *tp = tcp_sk(sk); struct rb_node *node, *prev; + bool pruned = false; int goal; if (RB_EMPTY_ROOT(&tp->out_of_order_queue)) return false; - NET_INC_STATS(sock_net(sk), LINUX_MIB_OFOPRUNED); goal = sk->sk_rcvbuf >> 3; node = &tp->ooo_last_skb->rbnode; + do { + struct sk_buff *skb = rb_to_skb(node); + + /* If incoming skb would land last in ofo queue, stop pruning. */ + if (after(TCP_SKB_CB(in_skb)->seq, TCP_SKB_CB(skb)->seq)) + break; + pruned = true; prev = rb_prev(node); rb_erase(node, &tp->out_of_order_queue); - goal -= rb_to_skb(node)->truesize; - tcp_drop_reason(sk, rb_to_skb(node), - SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE); + goal -= skb->truesize; + tcp_drop_reason(sk, skb, SKB_DROP_REASON_TCP_OFO_QUEUE_PRUNE); + tp->ooo_last_skb = rb_to_skb(prev); if (!prev || goal <= 0) { if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && !tcp_under_memory_pressure(sk)) @@ -5362,16 +5371,18 @@ static bool tcp_prune_ofo_queue(struct sock *sk) } node = prev; } while (node); - tp->ooo_last_skb = rb_to_skb(prev); - /* Reset SACK state. A conforming SACK implementation will - * do the same at a timeout based retransmit. When a connection - * is in a sad state like this, we care only about integrity - * of the connection not performance. - */ - if (tp->rx_opt.sack_ok) - tcp_sack_reset(&tp->rx_opt); - return true; + if (pruned) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_OFOPRUNED); + /* Reset SACK state. A conforming SACK implementation will + * do the same at a timeout based retransmit. When a connection + * is in a sad state like this, we care only about integrity + * of the connection not performance. + */ + if (tp->rx_opt.sack_ok) + tcp_sack_reset(&tp->rx_opt); + } + return pruned; } /* Reduce allocated memory if we can, trying to get @@ -5381,7 +5392,7 @@ static bool tcp_prune_ofo_queue(struct sock *sk) * until the socket owning process reads some of the data * to stabilize the situation. */ -static int tcp_prune_queue(struct sock *sk) +static int tcp_prune_queue(struct sock *sk, const struct sk_buff *in_skb) { struct tcp_sock *tp = tcp_sk(sk); @@ -5408,7 +5419,7 @@ static int tcp_prune_queue(struct sock *sk) /* Collapsing did not help, destructive actions follow. * This must not ever occur. */ - tcp_prune_ofo_queue(sk); + tcp_prune_ofo_queue(sk, in_skb); if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) return 0; |