tcp: speedup SIOCINQ ioctl

[~andy/linux] / net / ipv4 / tcp.c

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f32c02e2a54346cf4e120d39e17d4d1b5e966189..eace049da052befb0adf86c483b46fc8683e5419 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -536,30 +536,29 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 {
        struct tcp_sock *tp = tcp_sk(sk);
        int answ;
+       bool slow;
 
        switch (cmd) {
        case SIOCINQ:
                if (sk->sk_state == TCP_LISTEN)
                        return -EINVAL;
 
-               lock_sock(sk);
+               slow = lock_sock_fast(sk);
                if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
                        answ = 0;
                else if (sock_flag(sk, SOCK_URGINLINE) ||
                         !tp->urg_data ||
                         before(tp->urg_seq, tp->copied_seq) ||
                         !before(tp->urg_seq, tp->rcv_nxt)) {
-                       struct sk_buff *skb;
 
                        answ = tp->rcv_nxt - tp->copied_seq;
 
-                       /* Subtract 1, if FIN is in queue. */
-                       skb = skb_peek_tail(&sk->sk_receive_queue);
-                       if (answ && skb)
-                               answ -= tcp_hdr(skb)->fin;
+                       /* Subtract 1, if FIN was received */
+                       if (answ && sock_flag(sk, SOCK_DONE))
+                               answ--;
                } else
                        answ = tp->urg_seq - tp->copied_seq;
-               release_sock(sk);
+               unlock_sock_fast(sk, slow);
                break;
        case SIOCATMARK:
                answ = tp->urg_data && tp->urg_seq == tp->copied_seq;