From 8dce2786a2905e5b0ce49263910b4a47af75b752 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Fri, 26 Jan 2018 09:28:47 +0100 Subject: [PATCH] net/smc: smc_poll improvements Increase the socket refcount during poll wait. Take the socket lock before checking socket state. For a listening socket return a mask independent of state SMC_ACTIVE and cover errors or closed state as well. Get rid of the accept_q loop in smc_accept_poll(). Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/af_smc.c | 74 ++++++++++++++++++++++++++---------------------- 1 file changed, 40 insertions(+), 34 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index cf0e11978b66..90c22a854f28 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1122,21 +1122,15 @@ out: static unsigned int smc_accept_poll(struct sock *parent) { - struct smc_sock *isk; - struct sock *sk; - - lock_sock(parent); - list_for_each_entry(isk, &smc_sk(parent)->accept_q, accept_q) { - sk = (struct sock *)isk; + struct smc_sock *isk = smc_sk(parent); + int mask = 0; - if (sk->sk_state == SMC_ACTIVE) { - release_sock(parent); - return POLLIN | POLLRDNORM; - } - } - release_sock(parent); + spin_lock(&isk->accept_q_lock); + if (!list_empty(&isk->accept_q)) + mask = POLLIN | POLLRDNORM; + spin_unlock(&isk->accept_q_lock); - return 0; + return mask; } static unsigned int smc_poll(struct file *file, struct socket *sock, @@ -1147,9 +1141,15 @@ static unsigned int smc_poll(struct file *file, struct socket *sock, struct smc_sock *smc; int rc; + if (!sk) + return POLLNVAL; + smc = smc_sk(sock->sk); + sock_hold(sk); + lock_sock(sk); if ((sk->sk_state == SMC_INIT) || smc->use_fallback) { /* delegate to CLC child sock */ + release_sock(sk); mask = smc->clcsock->ops->poll(file, smc->clcsock, wait); /* if non-blocking connect finished ... */ lock_sock(sk); @@ -1161,37 +1161,43 @@ static unsigned int smc_poll(struct file *file, struct socket *sock, rc = smc_connect_rdma(smc); if (rc < 0) mask |= POLLERR; - else - /* success cases including fallback */ - mask |= POLLOUT | POLLWRNORM; + /* success cases including fallback */ + mask |= POLLOUT | POLLWRNORM; } } - release_sock(sk); } else { - sock_poll_wait(file, sk_sleep(sk), wait); - if (sk->sk_state == SMC_LISTEN) - /* woken up by sk_data_ready in smc_listen_work() */ - mask |= smc_accept_poll(sk); + if (sk->sk_state != SMC_CLOSED) { + release_sock(sk); + sock_poll_wait(file, sk_sleep(sk), wait); + lock_sock(sk); + } if (sk->sk_err) mask |= POLLERR; - if (atomic_read(&smc->conn.sndbuf_space) || - (sk->sk_shutdown & SEND_SHUTDOWN)) { - mask |= POLLOUT | POLLWRNORM; - } else { - sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); - set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); - } - if (atomic_read(&smc->conn.bytes_to_rcv)) - mask |= POLLIN | POLLRDNORM; if ((sk->sk_shutdown == SHUTDOWN_MASK) || (sk->sk_state == SMC_CLOSED)) mask |= POLLHUP; - if (sk->sk_shutdown & RCV_SHUTDOWN) - mask |= POLLIN | POLLRDNORM | POLLRDHUP; - if (sk->sk_state == SMC_APPCLOSEWAIT1) - mask |= POLLIN; + if (sk->sk_state == SMC_LISTEN) { + /* woken up by sk_data_ready in smc_listen_work() */ + mask = smc_accept_poll(sk); + } else { + if (atomic_read(&smc->conn.sndbuf_space) || + sk->sk_shutdown & SEND_SHUTDOWN) { + mask |= POLLOUT | POLLWRNORM; + } else { + sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); + } + if (atomic_read(&smc->conn.bytes_to_rcv)) + mask |= POLLIN | POLLRDNORM; + if (sk->sk_shutdown & RCV_SHUTDOWN) + mask |= POLLIN | POLLRDNORM | POLLRDHUP; + if (sk->sk_state == SMC_APPCLOSEWAIT1) + mask |= POLLIN; + } } + release_sock(sk); + sock_put(sk); return mask; } -- 2.30.2