Commit 1f6610b9 authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

mptcp: avoid unneeded indirection in mptcp_stream_accept() 



We are going to remove the first subflow socket soon, so avoid
the additional indirection at accept() time. Instead access
directly the first subflow sock, and update mptcp_accept() to
operate on it. This allows dropping a duplicated check in
mptcp_accept().

No functional changes intended.

Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarMat Martineau <martineau@kernel.org>
Signed-off-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5426a4ef

net/mptcp/protocol.c

+10 −19
Original line number Diff line number Diff line
@@ -3174,25 +3174,17 @@ void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk) 
	WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd);

}



static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,

static struct sock *mptcp_accept(struct sock *ssk, int flags, int *err,

				 bool kern)

{

	struct mptcp_sock *msk = mptcp_sk(sk);

	struct socket *listener;

	struct sock *newsk;



	listener = READ_ONCE(msk->subflow);

	if (WARN_ON_ONCE(!listener)) {

		*err = -EINVAL;

		return NULL;

	}



	pr_debug("msk=%p, listener=%p", msk, mptcp_subflow_ctx(listener->sk));

	newsk = inet_csk_accept(listener->sk, flags, err, kern);

	pr_debug("ssk=%p, listener=%p", ssk, mptcp_subflow_ctx(ssk));

	newsk = inet_csk_accept(ssk, flags, err, kern);

	if (!newsk)

		return NULL;



	pr_debug("msk=%p, subflow is mptcp=%d", msk, sk_is_mptcp(newsk));

	pr_debug("newsk=%p, subflow is mptcp=%d", newsk, sk_is_mptcp(newsk));

	if (sk_is_mptcp(newsk)) {

		struct mptcp_subflow_context *subflow;

		struct sock *new_mptcp_sock;
@@ -3209,9 +3201,9 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, 
		}



		newsk = new_mptcp_sock;

		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK);

		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPCAPABLEPASSIVEACK);

	} else {

		MPTCP_INC_STATS(sock_net(sk),

		MPTCP_INC_STATS(sock_net(ssk),

				MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK);

	}
@@ -3761,8 +3753,7 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, 
			       int flags, bool kern)

{

	struct mptcp_sock *msk = mptcp_sk(sock->sk);

	struct socket *ssock;

	struct sock *newsk;

	struct sock *ssk, *newsk;

	int err;



	pr_debug("msk=%p", msk);
@@ -3770,11 +3761,11 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, 
	/* Buggy applications can call accept on socket states other then LISTEN

	 * but no need to allocate the first subflow just to error out.

	 */

	ssock = READ_ONCE(msk->subflow);

	if (!ssock)

	ssk = READ_ONCE(msk->first);

	if (!ssk)

		return -EINVAL;



	newsk = mptcp_accept(sock->sk, flags, &err, kern);

	newsk = mptcp_accept(ssk, flags, &err, kern);

	if (!newsk)

		return err;