[PATCH net-next 2/5] net/smc: smc_poll improvements
From: Ursula Braun <hidden>
Date: 2018-01-26 08:29:02
Also in:
linux-rdma, linux-s390
Subsystem:
networking [general], shared memory communications (smc) sockets, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, D. Wythe, Dust Li, Sidraya Jayagond, Mahanta Jambigi, Linus Torvalds
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 <redacted> --- 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 @@ static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 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; }
--
2.13.5