From 71ba088ce0aa87370b18a1d35cd742f352d51c24 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Thu, 6 Jan 2022 16:20:17 -0800 Subject: [PATCH] mptcp: cleanup accept and poll After the previous patch, msk->subflow will never be deleted during the whole msk lifetime. We don't need anymore to acquire references to it in mptcp_stream_accept() and we can use the listener subflow accept queue to simplify mptcp_poll() for listener socket. Overall this removes a lock pair and 4 more atomic operations per accept(). Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 25 +++++++------------------ net/mptcp/protocol.h | 1 - net/mptcp/subflow.c | 1 - 3 files changed, 7 insertions(+), 20 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 83f6d6c3e3eb5..628cd60c9d0f9 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3493,17 +3493,9 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, pr_debug("msk=%p", msk); - lock_sock(sock->sk); - if (sock->sk->sk_state != TCP_LISTEN) - goto unlock_fail; - ssock = __mptcp_nmpc_socket(msk); if (!ssock) - goto unlock_fail; - - clear_bit(MPTCP_DATA_READY, &msk->flags); - sock_hold(ssock->sk); - release_sock(sock->sk); + return -EINVAL; err = ssock->ops->accept(sock, newsock, flags, kern); if (err == 0 && !mptcp_is_tcpsk(newsock->sk)) { @@ -3543,14 +3535,7 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, release_sock(newsk); } - if (inet_csk_listen_poll(ssock->sk)) - set_bit(MPTCP_DATA_READY, &msk->flags); - sock_put(ssock->sk); return err; - -unlock_fail: - release_sock(sock->sk); - return -EINVAL; } static __poll_t mptcp_check_readable(struct mptcp_sock *msk) @@ -3596,8 +3581,12 @@ static __poll_t mptcp_poll(struct file *file, struct socket *sock, state = inet_sk_state_load(sk); pr_debug("msk=%p state=%d flags=%lx", msk, state, msk->flags); - if (state == TCP_LISTEN) - return test_bit(MPTCP_DATA_READY, &msk->flags) ? EPOLLIN | EPOLLRDNORM : 0; + if (state == TCP_LISTEN) { + if (WARN_ON_ONCE(!msk->subflow || !msk->subflow->sk)) + return 0; + + return inet_csk_listen_poll(msk->subflow->sk); + } if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) { mask |= mptcp_check_readable(msk); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 1a4ca5a202c8f..386d1a98ff1d6 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -111,7 +111,6 @@ #define MPTCP_RST_TRANSIENT BIT(0) /* MPTCP socket flags */ -#define MPTCP_DATA_READY 0 #define MPTCP_NOSPACE 1 #define MPTCP_WORK_RTX 2 #define MPTCP_WORK_EOF 3 diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 24bc9d5e87be4..d861307f7efeb 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1293,7 +1293,6 @@ static void subflow_data_ready(struct sock *sk) if (reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue)) return; - set_bit(MPTCP_DATA_READY, &msk->flags); parent->sk_data_ready(parent); return; }