Commit 6cd66616 authored by Josef Bacik's avatar Josef Bacik Committed by David S. Miller
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inet: don't check for bind conflicts twice when searching for a port 



This is just wasted time, we've already found a tb that doesn't have a bind
conflict, and we don't drop the head lock so scanning again isn't going to give
us a different answer.  Instead move the tb->reuse setting logic outside of the
found_tb path and put it in the success: path.  Then make it so that we don't
goto again if we find a bind conflict in the found_tb path as we won't reach
this anymore when we are scanning for an ephemeral port.

Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b9470c27

net/ipv4/inet_connection_sock.c

+11 −20
Original line number Diff line number Diff line
@@ -164,7 +164,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum) 
{

	bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;

	struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo;

	int ret = 1, attempts = 5, port = snum;

	int ret = 1, port = snum;

	struct inet_bind_hashbucket *head;

	struct net *net = sock_net(sk);

	int i, low, high, attempt_half;
@@ -183,7 +183,6 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum) 


		goto tb_not_found;

	}

again:

	attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0;

other_half_scan:

	inet_get_local_port_range(net, &low, &high);
@@ -221,7 +220,7 @@ other_parity_scan: 
		inet_bind_bucket_for_each(tb, &head->chain)

			if (net_eq(ib_net(tb), net) && tb->port == port) {

				if (!inet_csk_bind_conflict(sk, tb, false, reuseport_ok))

					goto tb_found;

					goto success;

				goto next_port;

			}

		goto tb_not_found;
@@ -256,23 +255,11 @@ tb_found: 
		      !rcu_access_pointer(sk->sk_reuseport_cb) &&

		      sk->sk_reuseport && uid_eq(tb->fastuid, uid)))

			goto success;

		if (inet_csk_bind_conflict(sk, tb, true, reuseport_ok)) {

			if ((reuse ||

			     (tb->fastreuseport > 0 &&

			      sk->sk_reuseport &&

			      !rcu_access_pointer(sk->sk_reuseport_cb) &&

			      uid_eq(tb->fastuid, uid))) && !snum &&

			    --attempts >= 0) {

				spin_unlock_bh(&head->lock);

				goto again;

			}

		if (inet_csk_bind_conflict(sk, tb, true, reuseport_ok))

			goto fail_unlock;

	}

		if (!reuse)

			tb->fastreuse = 0;

		if (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid))

			tb->fastreuseport = 0;

	} else {

success:

	if (!hlist_empty(&tb->owners)) {

		tb->fastreuse = reuse;

		if (sk->sk_reuseport) {

			tb->fastreuseport = 1;
@@ -280,8 +267,12 @@ tb_found: 
		} else {

			tb->fastreuseport = 0;

		}

	} else {

		if (!reuse)

			tb->fastreuse = 0;

		if (!sk->sk_reuseport || !uid_eq(tb->fastuid, uid))

			tb->fastreuseport = 0;

	}

success:

	if (!inet_csk(sk)->icsk_bind_hash)

		inet_bind_hash(sk, tb, port);

	WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);

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