diff options
Diffstat (limited to 'net/smc/smc_close.c')
| -rw-r--r-- | net/smc/smc_close.c | 500 |
1 files changed, 500 insertions, 0 deletions
diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c new file mode 100644 index 000000000..bcd3ea894 --- /dev/null +++ b/net/smc/smc_close.c @@ -0,0 +1,500 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Shared Memory Communications over RDMA (SMC-R) and RoCE + * + * Socket Closing - normal and abnormal + * + * Copyright IBM Corp. 2016 + * + * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com> + */ + +#include <linux/workqueue.h> +#include <linux/sched/signal.h> + +#include <net/sock.h> +#include <net/tcp.h> + +#include "smc.h" +#include "smc_tx.h" +#include "smc_cdc.h" +#include "smc_close.h" + +/* release the clcsock that is assigned to the smc_sock */ +void smc_clcsock_release(struct smc_sock *smc) +{ + struct socket *tcp; + + if (smc->listen_smc && current_work() != &smc->smc_listen_work) + cancel_work_sync(&smc->smc_listen_work); + mutex_lock(&smc->clcsock_release_lock); + if (smc->clcsock) { + tcp = smc->clcsock; + smc->clcsock = NULL; + sock_release(tcp); + } + mutex_unlock(&smc->clcsock_release_lock); +} + +static void smc_close_cleanup_listen(struct sock *parent) +{ + struct sock *sk; + + /* Close non-accepted connections */ + while ((sk = smc_accept_dequeue(parent, NULL))) + smc_close_non_accepted(sk); +} + +/* wait for sndbuf data being transmitted */ +static void smc_close_stream_wait(struct smc_sock *smc, long timeout) +{ + DEFINE_WAIT_FUNC(wait, woken_wake_function); + struct sock *sk = &smc->sk; + + if (!timeout) + return; + + if (!smc_tx_prepared_sends(&smc->conn)) + return; + + smc->wait_close_tx_prepared = 1; + add_wait_queue(sk_sleep(sk), &wait); + while (!signal_pending(current) && timeout) { + int rc; + + rc = sk_wait_event(sk, &timeout, + !smc_tx_prepared_sends(&smc->conn) || + READ_ONCE(sk->sk_err) == ECONNABORTED || + READ_ONCE(sk->sk_err) == ECONNRESET || + smc->conn.killed, + &wait); + if (rc) + break; + } + remove_wait_queue(sk_sleep(sk), &wait); + smc->wait_close_tx_prepared = 0; +} + +void smc_close_wake_tx_prepared(struct smc_sock *smc) +{ + if (smc->wait_close_tx_prepared) + /* wake up socket closing */ + smc->sk.sk_state_change(&smc->sk); +} + +static int smc_close_wr(struct smc_connection *conn) +{ + conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1; + + return smc_cdc_get_slot_and_msg_send(conn); +} + +static int smc_close_final(struct smc_connection *conn) +{ + if (atomic_read(&conn->bytes_to_rcv)) + conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; + else + conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1; + if (conn->killed) + return -EPIPE; + + return smc_cdc_get_slot_and_msg_send(conn); +} + +int smc_close_abort(struct smc_connection *conn) +{ + conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; + + return smc_cdc_get_slot_and_msg_send(conn); +} + +static void smc_close_cancel_work(struct smc_sock *smc) +{ + struct sock *sk = &smc->sk; + + release_sock(sk); + if (cancel_work_sync(&smc->conn.close_work)) + sock_put(sk); + cancel_delayed_work_sync(&smc->conn.tx_work); + lock_sock(sk); +} + +/* terminate smc socket abnormally - active abort + * link group is terminated, i.e. RDMA communication no longer possible + */ +void smc_close_active_abort(struct smc_sock *smc) +{ + struct sock *sk = &smc->sk; + bool release_clcsock = false; + + if (sk->sk_state != SMC_INIT && smc->clcsock && smc->clcsock->sk) { + sk->sk_err = ECONNABORTED; + if (smc->clcsock && smc->clcsock->sk) + tcp_abort(smc->clcsock->sk, ECONNABORTED); + } + switch (sk->sk_state) { + case SMC_ACTIVE: + case SMC_APPCLOSEWAIT1: + case SMC_APPCLOSEWAIT2: + sk->sk_state = SMC_PEERABORTWAIT; + smc_close_cancel_work(smc); + if (sk->sk_state != SMC_PEERABORTWAIT) + break; + sk->sk_state = SMC_CLOSED; + sock_put(sk); /* (postponed) passive closing */ + break; + case SMC_PEERCLOSEWAIT1: + case SMC_PEERCLOSEWAIT2: + case SMC_PEERFINCLOSEWAIT: + sk->sk_state = SMC_PEERABORTWAIT; + smc_close_cancel_work(smc); + if (sk->sk_state != SMC_PEERABORTWAIT) + break; + sk->sk_state = SMC_CLOSED; + smc_conn_free(&smc->conn); + release_clcsock = true; + sock_put(sk); /* passive closing */ + break; + case SMC_PROCESSABORT: + case SMC_APPFINCLOSEWAIT: + sk->sk_state = SMC_PEERABORTWAIT; + smc_close_cancel_work(smc); + if (sk->sk_state != SMC_PEERABORTWAIT) + break; + sk->sk_state = SMC_CLOSED; + smc_conn_free(&smc->conn); + release_clcsock = true; + break; + case SMC_INIT: + case SMC_PEERABORTWAIT: + case SMC_CLOSED: + break; + } + + smc_sock_set_flag(sk, SOCK_DEAD); + sk->sk_state_change(sk); + + if (release_clcsock) { + release_sock(sk); + smc_clcsock_release(smc); + lock_sock(sk); + } +} + +static inline bool smc_close_sent_any_close(struct smc_connection *conn) +{ + return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort || + conn->local_tx_ctrl.conn_state_flags.peer_conn_closed; +} + +int smc_close_active(struct smc_sock *smc) +{ + struct smc_cdc_conn_state_flags *txflags = + &smc->conn.local_tx_ctrl.conn_state_flags; + struct smc_connection *conn = &smc->conn; + struct sock *sk = &smc->sk; + int old_state; + long timeout; + int rc = 0; + int rc1 = 0; + + timeout = current->flags & PF_EXITING ? + 0 : sock_flag(sk, SOCK_LINGER) ? + sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT; + + old_state = sk->sk_state; +again: + switch (sk->sk_state) { + case SMC_INIT: + sk->sk_state = SMC_CLOSED; + break; + case SMC_LISTEN: + sk->sk_state = SMC_CLOSED; + sk->sk_state_change(sk); /* wake up accept */ + if (smc->clcsock && smc->clcsock->sk) { + smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready; + smc->clcsock->sk->sk_user_data = NULL; + rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR); + } + smc_close_cleanup_listen(sk); + release_sock(sk); + flush_work(&smc->tcp_listen_work); + lock_sock(sk); + break; + case SMC_ACTIVE: + smc_close_stream_wait(smc, timeout); + release_sock(sk); + cancel_delayed_work_sync(&conn->tx_work); + lock_sock(sk); + if (sk->sk_state == SMC_ACTIVE) { + /* send close request */ + rc = smc_close_final(conn); + sk->sk_state = SMC_PEERCLOSEWAIT1; + + /* actively shutdown clcsock before peer close it, + * prevent peer from entering TIME_WAIT state. + */ + if (smc->clcsock && smc->clcsock->sk) { + rc1 = kernel_sock_shutdown(smc->clcsock, + SHUT_RDWR); + rc = rc ? rc : rc1; + } + } else { + /* peer event has changed the state */ + goto again; + } + break; + case SMC_APPFINCLOSEWAIT: + /* socket already shutdown wr or both (active close) */ + if (txflags->peer_done_writing && + !smc_close_sent_any_close(conn)) { + /* just shutdown wr done, send close request */ + rc = smc_close_final(conn); + } + sk->sk_state = SMC_CLOSED; + break; + case SMC_APPCLOSEWAIT1: + case SMC_APPCLOSEWAIT2: + if (!smc_cdc_rxed_any_close(conn)) + smc_close_stream_wait(smc, timeout); + release_sock(sk); + cancel_delayed_work_sync(&conn->tx_work); + lock_sock(sk); + if (sk->sk_state != SMC_APPCLOSEWAIT1 && + sk->sk_state != SMC_APPCLOSEWAIT2) + goto again; + /* confirm close from peer */ + rc = smc_close_final(conn); + if (smc_cdc_rxed_any_close(conn)) { + /* peer has closed the socket already */ + sk->sk_state = SMC_CLOSED; + sock_put(sk); /* postponed passive closing */ + } else { + /* peer has just issued a shutdown write */ + sk->sk_state = SMC_PEERFINCLOSEWAIT; + } + break; + case SMC_PEERCLOSEWAIT1: + case SMC_PEERCLOSEWAIT2: + if (txflags->peer_done_writing && + !smc_close_sent_any_close(conn)) { + /* just shutdown wr done, send close request */ + rc = smc_close_final(conn); + } + /* peer sending PeerConnectionClosed will cause transition */ + break; + case SMC_PEERFINCLOSEWAIT: + /* peer sending PeerConnectionClosed will cause transition */ + break; + case SMC_PROCESSABORT: + rc = smc_close_abort(conn); + sk->sk_state = SMC_CLOSED; + break; + case SMC_PEERABORTWAIT: + sk->sk_state = SMC_CLOSED; + break; + case SMC_CLOSED: + /* nothing to do, add tracing in future patch */ + break; + } + + if (old_state != sk->sk_state) + sk->sk_state_change(sk); + return rc; +} + +static void smc_close_passive_abort_received(struct smc_sock *smc) +{ + struct smc_cdc_conn_state_flags *txflags = + &smc->conn.local_tx_ctrl.conn_state_flags; + struct sock *sk = &smc->sk; + + switch (sk->sk_state) { + case SMC_INIT: + case SMC_ACTIVE: + case SMC_APPCLOSEWAIT1: + sk->sk_state = SMC_PROCESSABORT; + sock_put(sk); /* passive closing */ + break; + case SMC_APPFINCLOSEWAIT: + sk->sk_state = SMC_PROCESSABORT; + break; + case SMC_PEERCLOSEWAIT1: + case SMC_PEERCLOSEWAIT2: + if (txflags->peer_done_writing && + !smc_close_sent_any_close(&smc->conn)) + /* just shutdown, but not yet closed locally */ + sk->sk_state = SMC_PROCESSABORT; + else + sk->sk_state = SMC_CLOSED; + sock_put(sk); /* passive closing */ + break; + case SMC_APPCLOSEWAIT2: + case SMC_PEERFINCLOSEWAIT: + sk->sk_state = SMC_CLOSED; + sock_put(sk); /* passive closing */ + break; + case SMC_PEERABORTWAIT: + sk->sk_state = SMC_CLOSED; + break; + case SMC_PROCESSABORT: + /* nothing to do, add tracing in future patch */ + break; + } +} + +/* Either some kind of closing has been received: peer_conn_closed, + * peer_conn_abort, or peer_done_writing + * or the link group of the connection terminates abnormally. + */ +static void smc_close_passive_work(struct work_struct *work) +{ + struct smc_connection *conn = container_of(work, + struct smc_connection, + close_work); + struct smc_sock *smc = container_of(conn, struct smc_sock, conn); + struct smc_cdc_conn_state_flags *rxflags; + bool release_clcsock = false; + struct sock *sk = &smc->sk; + int old_state; + + lock_sock(sk); + old_state = sk->sk_state; + + rxflags = &conn->local_rx_ctrl.conn_state_flags; + if (rxflags->peer_conn_abort) { + /* peer has not received all data */ + smc_close_passive_abort_received(smc); + release_sock(&smc->sk); + cancel_delayed_work_sync(&conn->tx_work); + lock_sock(&smc->sk); + goto wakeup; + } + + switch (sk->sk_state) { + case SMC_INIT: + sk->sk_state = SMC_APPCLOSEWAIT1; + break; + case SMC_ACTIVE: + sk->sk_state = SMC_APPCLOSEWAIT1; + /* postpone sock_put() for passive closing to cover + * received SEND_SHUTDOWN as well + */ + break; + case SMC_PEERCLOSEWAIT1: + if (rxflags->peer_done_writing) + sk->sk_state = SMC_PEERCLOSEWAIT2; + fallthrough; + /* to check for closing */ + case SMC_PEERCLOSEWAIT2: + if (!smc_cdc_rxed_any_close(conn)) + break; + if (sock_flag(sk, SOCK_DEAD) && + smc_close_sent_any_close(conn)) { + /* smc_release has already been called locally */ + sk->sk_state = SMC_CLOSED; + } else { + /* just shutdown, but not yet closed locally */ + sk->sk_state = SMC_APPFINCLOSEWAIT; + } + sock_put(sk); /* passive closing */ + break; + case SMC_PEERFINCLOSEWAIT: + if (smc_cdc_rxed_any_close(conn)) { + sk->sk_state = SMC_CLOSED; + sock_put(sk); /* passive closing */ + } + break; + case SMC_APPCLOSEWAIT1: + case SMC_APPCLOSEWAIT2: + /* postpone sock_put() for passive closing to cover + * received SEND_SHUTDOWN as well + */ + break; + case SMC_APPFINCLOSEWAIT: + case SMC_PEERABORTWAIT: + case SMC_PROCESSABORT: + case SMC_CLOSED: + /* nothing to do, add tracing in future patch */ + break; + } + +wakeup: + sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */ + sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */ + + if (old_state != sk->sk_state) { + sk->sk_state_change(sk); + if ((sk->sk_state == SMC_CLOSED) && + (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) { + smc_conn_free(conn); + if (smc->clcsock) + release_clcsock = true; + } + } + release_sock(sk); + if (release_clcsock) + smc_clcsock_release(smc); + sock_put(sk); /* sock_hold done by schedulers of close_work */ +} + +int smc_close_shutdown_write(struct smc_sock *smc) +{ + struct smc_connection *conn = &smc->conn; + struct sock *sk = &smc->sk; + int old_state; + long timeout; + int rc = 0; + + timeout = current->flags & PF_EXITING ? + 0 : sock_flag(sk, SOCK_LINGER) ? + sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT; + + old_state = sk->sk_state; +again: + switch (sk->sk_state) { + case SMC_ACTIVE: + smc_close_stream_wait(smc, timeout); + release_sock(sk); + cancel_delayed_work_sync(&conn->tx_work); + lock_sock(sk); + if (sk->sk_state != SMC_ACTIVE) + goto again; + /* send close wr request */ + rc = smc_close_wr(conn); + sk->sk_state = SMC_PEERCLOSEWAIT1; + break; + case SMC_APPCLOSEWAIT1: + /* passive close */ + if (!smc_cdc_rxed_any_close(conn)) + smc_close_stream_wait(smc, timeout); + release_sock(sk); + cancel_delayed_work_sync(&conn->tx_work); + lock_sock(sk); + if (sk->sk_state != SMC_APPCLOSEWAIT1) + goto again; + /* confirm close from peer */ + rc = smc_close_wr(conn); + sk->sk_state = SMC_APPCLOSEWAIT2; + break; + case SMC_APPCLOSEWAIT2: + case SMC_PEERFINCLOSEWAIT: + case SMC_PEERCLOSEWAIT1: + case SMC_PEERCLOSEWAIT2: + case SMC_APPFINCLOSEWAIT: + case SMC_PROCESSABORT: + case SMC_PEERABORTWAIT: + /* nothing to do, add tracing in future patch */ + break; + } + + if (old_state != sk->sk_state) + sk->sk_state_change(sk); + return rc; +} + +/* Initialize close properties on connection establishment. */ +void smc_close_init(struct smc_sock *smc) +{ + INIT_WORK(&smc->conn.close_work, smc_close_passive_work); +} |