LXR linux/net/smc/smc

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4 *
   5 *  Socket Closing - normal and abnormal
   6 *
   7 *  Copyright IBM Corp. 2016
   8 *
   9 *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  10 */
  11
  12#include <linux/workqueue.h>
  13#include <linux/sched/signal.h>
  14
  15#include <net/sock.h>
  16#include <net/tcp.h>
  17
  18#include "smc.h"
  19#include "smc_tx.h"
  20#include "smc_cdc.h"
  21#include "smc_close.h"
  22
  23/* release the clcsock that is assigned to the smc_sock */
  24void smc_clcsock_release(struct smc_sock *smc)
  25{
  26        struct socket *tcp;
  27
  28        if (smc->listen_smc && current_work() != &smc->smc_listen_work)
  29                cancel_work_sync(&smc->smc_listen_work);
  30        mutex_lock(&smc->clcsock_release_lock);
  31        if (smc->clcsock) {
  32                tcp = smc->clcsock;
  33                smc->clcsock = NULL;
  34                sock_release(tcp);
  35        }
  36        mutex_unlock(&smc->clcsock_release_lock);
  37}
  38
  39static void smc_close_cleanup_listen(struct sock *parent)
  40{
  41        struct sock *sk;
  42
  43        /* Close non-accepted connections */
  44        while ((sk = smc_accept_dequeue(parent, NULL)))
  45                smc_close_non_accepted(sk);
  46}
  47
  48/* wait for sndbuf data being transmitted */
  49static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
  50{
  51        DEFINE_WAIT_FUNC(wait, woken_wake_function);
  52        struct sock *sk = &smc->sk;
  53
  54        if (!timeout)
  55                return;
  56
  57        if (!smc_tx_prepared_sends(&smc->conn))
  58                return;
  59
  60        smc->wait_close_tx_prepared = 1;
  61        add_wait_queue(sk_sleep(sk), &wait);
  62        while (!signal_pending(current) && timeout) {
  63                int rc;
  64
  65                rc = sk_wait_event(sk, &timeout,
  66                                   !smc_tx_prepared_sends(&smc->conn) ||
  67                                   sk->sk_err == ECONNABORTED ||
  68                                   sk->sk_err == ECONNRESET ||
  69                                   smc->conn.killed,
  70                                   &wait);
  71                if (rc)
  72                        break;
  73        }
  74        remove_wait_queue(sk_sleep(sk), &wait);
  75        smc->wait_close_tx_prepared = 0;
  76}
  77
  78void smc_close_wake_tx_prepared(struct smc_sock *smc)
  79{
  80        if (smc->wait_close_tx_prepared)
  81                /* wake up socket closing */
  82                smc->sk.sk_state_change(&smc->sk);
  83}
  84
  85static int smc_close_wr(struct smc_connection *conn)
  86{
  87        conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;
  88
  89        return smc_cdc_get_slot_and_msg_send(conn);
  90}
  91
  92static int smc_close_final(struct smc_connection *conn)
  93{
  94        if (atomic_read(&conn->bytes_to_rcv))
  95                conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
  96        else
  97                conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
  98        if (conn->killed)
  99                return -EPIPE;
 100
 101        return smc_cdc_get_slot_and_msg_send(conn);
 102}
 103
 104int smc_close_abort(struct smc_connection *conn)
 105{
 106        conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 107
 108        return smc_cdc_get_slot_and_msg_send(conn);
 109}
 110
 111static void smc_close_cancel_work(struct smc_sock *smc)
 112{
 113        struct sock *sk = &smc->sk;
 114
 115        release_sock(sk);
 116        cancel_work_sync(&smc->conn.close_work);
 117        cancel_delayed_work_sync(&smc->conn.tx_work);
 118        lock_sock(sk);
 119}
 120
 121/* terminate smc socket abnormally - active abort
 122 * link group is terminated, i.e. RDMA communication no longer possible
 123 */
 124void smc_close_active_abort(struct smc_sock *smc)
 125{
 126        struct sock *sk = &smc->sk;
 127        bool release_clcsock = false;
 128
 129        if (sk->sk_state != SMC_INIT && smc->clcsock && smc->clcsock->sk) {
 130                sk->sk_err = ECONNABORTED;
 131                if (smc->clcsock && smc->clcsock->sk)
 132                        tcp_abort(smc->clcsock->sk, ECONNABORTED);
 133        }
 134        switch (sk->sk_state) {
 135        case SMC_ACTIVE:
 136        case SMC_APPCLOSEWAIT1:
 137        case SMC_APPCLOSEWAIT2:
 138                sk->sk_state = SMC_PEERABORTWAIT;
 139                smc_close_cancel_work(smc);
 140                if (sk->sk_state != SMC_PEERABORTWAIT)
 141                        break;
 142                sk->sk_state = SMC_CLOSED;
 143                sock_put(sk); /* (postponed) passive closing */
 144                break;
 145        case SMC_PEERCLOSEWAIT1:
 146        case SMC_PEERCLOSEWAIT2:
 147        case SMC_PEERFINCLOSEWAIT:
 148                sk->sk_state = SMC_PEERABORTWAIT;
 149                smc_close_cancel_work(smc);
 150                if (sk->sk_state != SMC_PEERABORTWAIT)
 151                        break;
 152                sk->sk_state = SMC_CLOSED;
 153                smc_conn_free(&smc->conn);
 154                release_clcsock = true;
 155                sock_put(sk); /* passive closing */
 156                break;
 157        case SMC_PROCESSABORT:
 158        case SMC_APPFINCLOSEWAIT:
 159                sk->sk_state = SMC_PEERABORTWAIT;
 160                smc_close_cancel_work(smc);
 161                if (sk->sk_state != SMC_PEERABORTWAIT)
 162                        break;
 163                sk->sk_state = SMC_CLOSED;
 164                smc_conn_free(&smc->conn);
 165                release_clcsock = true;
 166                break;
 167        case SMC_INIT:
 168        case SMC_PEERABORTWAIT:
 169        case SMC_CLOSED:
 170                break;
 171        }
 172
 173        sock_set_flag(sk, SOCK_DEAD);
 174        sk->sk_state_change(sk);
 175
 176        if (release_clcsock) {
 177                release_sock(sk);
 178                smc_clcsock_release(smc);
 179                lock_sock(sk);
 180        }
 181}
 182
 183static inline bool smc_close_sent_any_close(struct smc_connection *conn)
 184{
 185        return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
 186               conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
 187}
 188
 189int smc_close_active(struct smc_sock *smc)
 190{
 191        struct smc_cdc_conn_state_flags *txflags =
 192                &smc->conn.local_tx_ctrl.conn_state_flags;
 193        struct smc_connection *conn = &smc->conn;
 194        struct sock *sk = &smc->sk;
 195        int old_state;
 196        long timeout;
 197        int rc = 0;
 198
 199        timeout = current->flags & PF_EXITING ?
 200                  0 : sock_flag(sk, SOCK_LINGER) ?
 201                      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 202
 203        old_state = sk->sk_state;
 204again:
 205        switch (sk->sk_state) {
 206        case SMC_INIT:
 207                sk->sk_state = SMC_CLOSED;
 208                break;
 209        case SMC_LISTEN:
 210                sk->sk_state = SMC_CLOSED;
 211                sk->sk_state_change(sk); /* wake up accept */
 212                if (smc->clcsock && smc->clcsock->sk) {
 213                        smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
 214                        smc->clcsock->sk->sk_user_data = NULL;
 215                        rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
 216                }
 217                smc_close_cleanup_listen(sk);
 218                release_sock(sk);
 219                flush_work(&smc->tcp_listen_work);
 220                lock_sock(sk);
 221                break;
 222        case SMC_ACTIVE:
 223                smc_close_stream_wait(smc, timeout);
 224                release_sock(sk);
 225                cancel_delayed_work_sync(&conn->tx_work);
 226                lock_sock(sk);
 227                if (sk->sk_state == SMC_ACTIVE) {
 228                        /* send close request */
 229                        rc = smc_close_final(conn);
 230                        sk->sk_state = SMC_PEERCLOSEWAIT1;
 231                } else {
 232                        /* peer event has changed the state */
 233                        goto again;
 234                }
 235                break;
 236        case SMC_APPFINCLOSEWAIT:
 237                /* socket already shutdown wr or both (active close) */
 238                if (txflags->peer_done_writing &&
 239                    !smc_close_sent_any_close(conn)) {
 240                        /* just shutdown wr done, send close request */
 241                        rc = smc_close_final(conn);
 242                }
 243                sk->sk_state = SMC_CLOSED;
 244                break;
 245        case SMC_APPCLOSEWAIT1:
 246        case SMC_APPCLOSEWAIT2:
 247                if (!smc_cdc_rxed_any_close(conn))
 248                        smc_close_stream_wait(smc, timeout);
 249                release_sock(sk);
 250                cancel_delayed_work_sync(&conn->tx_work);
 251                lock_sock(sk);
 252                if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
 253                    sk->sk_state != SMC_APPCLOSEWAIT2)
 254                        goto again;
 255                /* confirm close from peer */
 256                rc = smc_close_final(conn);
 257                if (smc_cdc_rxed_any_close(conn)) {
 258                        /* peer has closed the socket already */
 259                        sk->sk_state = SMC_CLOSED;
 260                        sock_put(sk); /* postponed passive closing */
 261                } else {
 262                        /* peer has just issued a shutdown write */
 263                        sk->sk_state = SMC_PEERFINCLOSEWAIT;
 264                }
 265                break;
 266        case SMC_PEERCLOSEWAIT1:
 267        case SMC_PEERCLOSEWAIT2:
 268                if (txflags->peer_done_writing &&
 269                    !smc_close_sent_any_close(conn)) {
 270                        /* just shutdown wr done, send close request */
 271                        rc = smc_close_final(conn);
 272                }
 273                /* peer sending PeerConnectionClosed will cause transition */
 274                break;
 275        case SMC_PEERFINCLOSEWAIT:
 276                /* peer sending PeerConnectionClosed will cause transition */
 277                break;
 278        case SMC_PROCESSABORT:
 279                rc = smc_close_abort(conn);
 280                sk->sk_state = SMC_CLOSED;
 281                break;
 282        case SMC_PEERABORTWAIT:
 283                sk->sk_state = SMC_CLOSED;
 284                break;
 285        case SMC_CLOSED:
 286                /* nothing to do, add tracing in future patch */
 287                break;
 288        }
 289
 290        if (old_state != sk->sk_state)
 291                sk->sk_state_change(sk);
 292        return rc;
 293}
 294
 295static void smc_close_passive_abort_received(struct smc_sock *smc)
 296{
 297        struct smc_cdc_conn_state_flags *txflags =
 298                &smc->conn.local_tx_ctrl.conn_state_flags;
 299        struct sock *sk = &smc->sk;
 300
 301        switch (sk->sk_state) {
 302        case SMC_INIT:
 303        case SMC_ACTIVE:
 304        case SMC_APPCLOSEWAIT1:
 305                sk->sk_state = SMC_PROCESSABORT;
 306                sock_put(sk); /* passive closing */
 307                break;
 308        case SMC_APPFINCLOSEWAIT:
 309                sk->sk_state = SMC_PROCESSABORT;
 310                break;
 311        case SMC_PEERCLOSEWAIT1:
 312        case SMC_PEERCLOSEWAIT2:
 313                if (txflags->peer_done_writing &&
 314                    !smc_close_sent_any_close(&smc->conn))
 315                        /* just shutdown, but not yet closed locally */
 316                        sk->sk_state = SMC_PROCESSABORT;
 317                else
 318                        sk->sk_state = SMC_CLOSED;
 319                sock_put(sk); /* passive closing */
 320                break;
 321        case SMC_APPCLOSEWAIT2:
 322        case SMC_PEERFINCLOSEWAIT:
 323                sk->sk_state = SMC_CLOSED;
 324                sock_put(sk); /* passive closing */
 325                break;
 326        case SMC_PEERABORTWAIT:
 327                sk->sk_state = SMC_CLOSED;
 328                break;
 329        case SMC_PROCESSABORT:
 330        /* nothing to do, add tracing in future patch */
 331                break;
 332        }
 333}
 334
 335/* Either some kind of closing has been received: peer_conn_closed,
 336 * peer_conn_abort, or peer_done_writing
 337 * or the link group of the connection terminates abnormally.
 338 */
 339static void smc_close_passive_work(struct work_struct *work)
 340{
 341        struct smc_connection *conn = container_of(work,
 342                                                   struct smc_connection,
 343                                                   close_work);
 344        struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 345        struct smc_cdc_conn_state_flags *rxflags;
 346        bool release_clcsock = false;
 347        struct sock *sk = &smc->sk;
 348        int old_state;
 349
 350        lock_sock(sk);
 351        old_state = sk->sk_state;
 352
 353        rxflags = &conn->local_rx_ctrl.conn_state_flags;
 354        if (rxflags->peer_conn_abort) {
 355                /* peer has not received all data */
 356                smc_close_passive_abort_received(smc);
 357                release_sock(&smc->sk);
 358                cancel_delayed_work_sync(&conn->tx_work);
 359                lock_sock(&smc->sk);
 360                goto wakeup;
 361        }
 362
 363        switch (sk->sk_state) {
 364        case SMC_INIT:
 365                sk->sk_state = SMC_APPCLOSEWAIT1;
 366                break;
 367        case SMC_ACTIVE:
 368                sk->sk_state = SMC_APPCLOSEWAIT1;
 369                /* postpone sock_put() for passive closing to cover
 370                 * received SEND_SHUTDOWN as well
 371                 */
 372                break;
 373        case SMC_PEERCLOSEWAIT1:
 374                if (rxflags->peer_done_writing)
 375                        sk->sk_state = SMC_PEERCLOSEWAIT2;
 376                fallthrough;
 377                /* to check for closing */
 378        case SMC_PEERCLOSEWAIT2:
 379                if (!smc_cdc_rxed_any_close(conn))
 380                        break;
 381                if (sock_flag(sk, SOCK_DEAD) &&
 382                    smc_close_sent_any_close(conn)) {
 383                        /* smc_release has already been called locally */
 384                        sk->sk_state = SMC_CLOSED;
 385                } else {
 386                        /* just shutdown, but not yet closed locally */
 387                        sk->sk_state = SMC_APPFINCLOSEWAIT;
 388                }
 389                sock_put(sk); /* passive closing */
 390                break;
 391        case SMC_PEERFINCLOSEWAIT:
 392                if (smc_cdc_rxed_any_close(conn)) {
 393                        sk->sk_state = SMC_CLOSED;
 394                        sock_put(sk); /* passive closing */
 395                }
 396                break;
 397        case SMC_APPCLOSEWAIT1:
 398        case SMC_APPCLOSEWAIT2:
 399                /* postpone sock_put() for passive closing to cover
 400                 * received SEND_SHUTDOWN as well
 401                 */
 402                break;
 403        case SMC_APPFINCLOSEWAIT:
 404        case SMC_PEERABORTWAIT:
 405        case SMC_PROCESSABORT:
 406        case SMC_CLOSED:
 407                /* nothing to do, add tracing in future patch */
 408                break;
 409        }
 410
 411wakeup:
 412        sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
 413        sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
 414
 415        if (old_state != sk->sk_state) {
 416                sk->sk_state_change(sk);
 417                if ((sk->sk_state == SMC_CLOSED) &&
 418                    (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
 419                        smc_conn_free(conn);
 420                        if (smc->clcsock)
 421                                release_clcsock = true;
 422                }
 423        }
 424        release_sock(sk);
 425        if (release_clcsock)
 426                smc_clcsock_release(smc);
 427        sock_put(sk); /* sock_hold done by schedulers of close_work */
 428}
 429
 430int smc_close_shutdown_write(struct smc_sock *smc)
 431{
 432        struct smc_connection *conn = &smc->conn;
 433        struct sock *sk = &smc->sk;
 434        int old_state;
 435        long timeout;
 436        int rc = 0;
 437
 438        timeout = current->flags & PF_EXITING ?
 439                  0 : sock_flag(sk, SOCK_LINGER) ?
 440                      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 441
 442        old_state = sk->sk_state;
 443again:
 444        switch (sk->sk_state) {
 445        case SMC_ACTIVE:
 446                smc_close_stream_wait(smc, timeout);
 447                release_sock(sk);
 448                cancel_delayed_work_sync(&conn->tx_work);
 449                lock_sock(sk);
 450                if (sk->sk_state != SMC_ACTIVE)
 451                        goto again;
 452                /* send close wr request */
 453                rc = smc_close_wr(conn);
 454                sk->sk_state = SMC_PEERCLOSEWAIT1;
 455                break;
 456        case SMC_APPCLOSEWAIT1:
 457                /* passive close */
 458                if (!smc_cdc_rxed_any_close(conn))
 459                        smc_close_stream_wait(smc, timeout);
 460                release_sock(sk);
 461                cancel_delayed_work_sync(&conn->tx_work);
 462                lock_sock(sk);
 463                if (sk->sk_state != SMC_APPCLOSEWAIT1)
 464                        goto again;
 465                /* confirm close from peer */
 466                rc = smc_close_wr(conn);
 467                sk->sk_state = SMC_APPCLOSEWAIT2;
 468                break;
 469        case SMC_APPCLOSEWAIT2:
 470        case SMC_PEERFINCLOSEWAIT:
 471        case SMC_PEERCLOSEWAIT1:
 472        case SMC_PEERCLOSEWAIT2:
 473        case SMC_APPFINCLOSEWAIT:
 474        case SMC_PROCESSABORT:
 475        case SMC_PEERABORTWAIT:
 476                /* nothing to do, add tracing in future patch */
 477                break;
 478        }
 479
 480        if (old_state != sk->sk_state)
 481                sk->sk_state_change(sk);
 482        return rc;
 483}
 484
 485/* Initialize close properties on connection establishment. */
 486void smc_close_init(struct smc_sock *smc)
 487{
 488        INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
 489}
 490