// 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) || sk->sk_err == ECONNABORTED || 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); cancel_work_sync(&smc->conn.close_work); 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; } 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; 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; } 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); }