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Release 4.14 net/smc/smc_close.c

Directory: net/smc
// 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 "smc.h"
#include "smc_tx.h"
#include "smc_cdc.h"
#include "smc_close.h"


#define SMC_CLOSE_WAIT_TX_PENDS_TIME		(5 * HZ)


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); }

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static void smc_close_wait_tx_pends(struct smc_sock *smc) { DEFINE_WAIT_FUNC(wait, woken_wake_function); struct sock *sk = &smc->sk; signed long timeout; timeout = SMC_CLOSE_WAIT_TX_PENDS_TIME; add_wait_queue(sk_sleep(sk), &wait); while (!signal_pending(current) && timeout) { int rc; rc = sk_wait_event(sk, &timeout, !smc_cdc_tx_has_pending(&smc->conn), &wait); if (rc) break; } remove_wait_queue(sk_sleep(sk), &wait); }

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/* 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), &wait); if (rc) break; } remove_wait_queue(sk_sleep(sk), &wait); smc->wait_close_tx_prepared = 0; }

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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); }

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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); }

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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; return smc_cdc_get_slot_and_msg_send(conn); }

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static 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); }

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/* terminate smc socket abnormally - active abort * RDMA communication no longer possible */
void smc_close_active_abort(struct smc_sock *smc) { struct smc_cdc_conn_state_flags *txflags = &smc->conn.local_tx_ctrl.conn_state_flags; smc->sk.sk_err = ECONNABORTED; if (smc->clcsock && smc->clcsock->sk) { smc->clcsock->sk->sk_err = ECONNABORTED; smc->clcsock->sk->sk_state_change(smc->clcsock->sk); } switch (smc->sk.sk_state) { case SMC_INIT: case SMC_ACTIVE: smc->sk.sk_state = SMC_PEERABORTWAIT; break; case SMC_APPCLOSEWAIT1: case SMC_APPCLOSEWAIT2: txflags->peer_conn_abort = 1; sock_release(smc->clcsock); if (!smc_cdc_rxed_any_close(&smc->conn)) smc->sk.sk_state = SMC_PEERABORTWAIT; else smc->sk.sk_state = SMC_CLOSED; break; case SMC_PEERCLOSEWAIT1: case SMC_PEERCLOSEWAIT2: if (!txflags->peer_conn_closed) { smc->sk.sk_state = SMC_PEERABORTWAIT; txflags->peer_conn_abort = 1; sock_release(smc->clcsock); } else { smc->sk.sk_state = SMC_CLOSED; } break; case SMC_PROCESSABORT: case SMC_APPFINCLOSEWAIT: if (!txflags->peer_conn_closed) { txflags->peer_conn_abort = 1; sock_release(smc->clcsock); } smc->sk.sk_state = SMC_CLOSED; break; case SMC_PEERFINCLOSEWAIT: case SMC_PEERABORTWAIT: case SMC_CLOSED: break; } sock_set_flag(&smc->sk, SOCK_DEAD); smc->sk.sk_state_change(&smc->sk); }

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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; }

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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; again: old_state = sk->sk_state; switch (old_state) { case SMC_INIT: sk->sk_state = SMC_CLOSED; if (smc->smc_listen_work.func) cancel_work_sync(&smc->smc_listen_work); break; case SMC_LISTEN: sk->sk_state = SMC_CLOSED; sk->sk_state_change(sk); /* wake up accept */ if (smc->clcsock && smc->clcsock->sk) { rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR); /* wake up kernel_accept of smc_tcp_listen_worker */ smc->clcsock->sk->sk_data_ready(smc->clcsock->sk); } release_sock(sk); smc_close_cleanup_listen(sk); cancel_work_sync(&smc->smc_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; smc_close_wait_tx_pends(smc); 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_err != ECONNABORTED) { /* confirm close from peer */ rc = smc_close_final(conn); if (rc) break; } if (smc_cdc_rxed_any_close(conn)) /* peer has closed the socket already */ sk->sk_state = SMC_CLOSED; else /* peer has just issued a shutdown write */ sk->sk_state = SMC_PEERFINCLOSEWAIT; smc_close_wait_tx_pends(smc); 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: release_sock(sk); cancel_delayed_work_sync(&conn->tx_work); lock_sock(sk); smc_close_abort(conn); sk->sk_state = SMC_CLOSED; smc_close_wait_tx_pends(smc); break; case SMC_PEERABORTWAIT: case SMC_CLOSED: /* nothing to do, add tracing in future patch */ break; } if (old_state != sk->sk_state) sk->sk_state_change(&smc->sk); return rc; }

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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_ACTIVE: case SMC_APPFINCLOSEWAIT: case SMC_APPCLOSEWAIT1: case SMC_APPCLOSEWAIT2: smc_close_abort(&smc->conn); 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 */ smc_close_abort(&smc->conn); sk->sk_state = SMC_PROCESSABORT; } else { sk->sk_state = SMC_CLOSED; } break; case SMC_PEERFINCLOSEWAIT: case SMC_PEERABORTWAIT: sk->sk_state = SMC_CLOSED; break; case SMC_INIT: case SMC_PROCESSABORT: /* nothing to do, add tracing in future patch */ break; } }

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/* Some kind of closing has been received: peer_conn_closed, peer_conn_abort, * or peer_done_writing. */
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; struct sock *sk = &smc->sk; int old_state; lock_sock(&smc->sk); old_state = sk->sk_state; if (!conn->alert_token_local) { /* abnormal termination */ smc_close_active_abort(smc); goto wakeup; } rxflags = &smc->conn.local_rx_ctrl.conn_state_flags; if (rxflags->peer_conn_abort) { smc_close_passive_abort_received(smc); goto wakeup; } switch (sk->sk_state) { case SMC_INIT: if (atomic_read(&smc->conn.bytes_to_rcv) || (rxflags->peer_done_writing && !smc_cdc_rxed_any_close(conn))) sk->sk_state = SMC_APPCLOSEWAIT1; else sk->sk_state = SMC_CLOSED; break; case SMC_ACTIVE: sk->sk_state = SMC_APPCLOSEWAIT1; break; case SMC_PEERCLOSEWAIT1: if (rxflags->peer_done_writing) sk->sk_state = SMC_PEERCLOSEWAIT2; /* fall through to check for closing */ case SMC_PEERCLOSEWAIT2: case SMC_PEERFINCLOSEWAIT: if (!smc_cdc_rxed_any_close(&smc->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; } break; case SMC_APPCLOSEWAIT1: case SMC_APPCLOSEWAIT2: 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(&smc->conn); schedule_delayed_work(&smc->sock_put_work, SMC_CLOSE_SOCK_PUT_DELAY); } } release_sock(&smc->sk); }

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void smc_close_sock_put_work(struct work_struct *work) { struct smc_sock *smc = container_of(to_delayed_work(work), struct smc_sock, sock_put_work); smc->sk.sk_prot->unhash(&smc->sk); sock_put(&smc->sk); }

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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; again: old_state = sk->sk_state; switch (old_state) { case SMC_ACTIVE: smc_close_stream_wait(smc, timeout); release_sock(sk); cancel_delayed_work_sync(&conn->tx_work); lock_sock(sk); /* send close wr request */ rc = smc_close_wr(conn); if (sk->sk_state == SMC_ACTIVE) sk->sk_state = SMC_PEERCLOSEWAIT1; else goto again; 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); /* 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(&smc->sk); return rc; }

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/* Initialize close properties on connection establishment. */
void smc_close_init(struct smc_sock *smc) { INIT_WORK(&smc->conn.close_work, smc_close_passive_work); }

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Directory: net/smc
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