Commit 0e71c55c authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: speedup SIOCINQ ioctl 



SIOCINQ can use the lock_sock_fast() version to avoid double acquisition
of socket lock.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 354e4aa3

net/ipv4/tcp.c

+3 −2
Original line number Diff line number Diff line
@@ -536,13 +536,14 @@ 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) ||
@@ -557,7 +558,7 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 
				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;