From 1f6610b92ac3c4cd4b7904b1d00b776f9bf08ed3 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 11 Aug 2023 17:57:22 +0200 Subject: [PATCH] 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: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 29 ++++++++++------------------- 1 file changed, 10 insertions(+), 19 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e89d1bf44f77..e5ebd170d316 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -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; -- 2.20.1