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        int rc1 = 0;
 199
 200        timeout = current->flags & PF_EXITING ?
 201                  0 : sock_flag(sk, SOCK_LINGER) ?
 202                      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 203
 204        old_state = sk->sk_state;
 205again:
 206        switch (sk->sk_state) {
 207        case SMC_INIT:
 208                sk->sk_state = SMC_CLOSED;
 209                break;
 210        case SMC_LISTEN:
 211                sk->sk_state = SMC_CLOSED;
 212                sk->sk_state_change(sk); /* wake up accept */
 213                if (smc->clcsock && smc->clcsock->sk) {
 214                        smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
 215                        smc->clcsock->sk->sk_user_data = NULL;
 216                        rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
 217                }
 218                smc_close_cleanup_listen(sk);
 219                release_sock(sk);
 220                flush_work(&smc->tcp_listen_work);
 221                lock_sock(sk);
 222                break;
 223        case SMC_ACTIVE:
 224                smc_close_stream_wait(smc, timeout);
 225                release_sock(sk);
 226                cancel_delayed_work_sync(&conn->tx_work);
 227                lock_sock(sk);
 228                if (sk->sk_state == SMC_ACTIVE) {
 229                        /* send close request */
 230                        rc = smc_close_final(conn);
 231                        sk->sk_state = SMC_PEERCLOSEWAIT1;
 232
 233                        /* actively shutdown clcsock before peer close it,
 234                         * prevent peer from entering TIME_WAIT state.
 235                         */
 236                        if (smc->clcsock && smc->clcsock->sk) {
 237                                rc1 = kernel_sock_shutdown(smc->clcsock,
 238                                                           SHUT_RDWR);
 239                                rc = rc ? rc : rc1;
 240                        }
 241                } else {
 242                        /* peer event has changed the state */
 243                        goto again;
 244                }
 245                break;
 246        case SMC_APPFINCLOSEWAIT:
 247                /* socket already shutdown wr or both (active close) */
 248                if (txflags->peer_done_writing &&
 249                    !smc_close_sent_any_close(conn)) {
 250                        /* just shutdown wr done, send close request */
 251                        rc = smc_close_final(conn);
 252                }
 253                sk->sk_state = SMC_CLOSED;
 254                break;
 255        case SMC_APPCLOSEWAIT1:
 256        case SMC_APPCLOSEWAIT2:
 257                if (!smc_cdc_rxed_any_close(conn))
 258                        smc_close_stream_wait(smc, timeout);
 259                release_sock(sk);
 260                cancel_delayed_work_sync(&conn->tx_work);
 261                lock_sock(sk);
 262                if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
 263                    sk->sk_state != SMC_APPCLOSEWAIT2)
 264                        goto again;
 265                /* confirm close from peer */
 266                rc = smc_close_final(conn);
 267                if (smc_cdc_rxed_any_close(conn)) {
 268                        /* peer has closed the socket already */
 269                        sk->sk_state = SMC_CLOSED;
 270                        sock_put(sk); /* postponed passive closing */
 271                } else {
 272                        /* peer has just issued a shutdown write */
 273                        sk->sk_state = SMC_PEERFINCLOSEWAIT;
 274                }
 275                break;
 276        case SMC_PEERCLOSEWAIT1:
 277        case SMC_PEERCLOSEWAIT2:
 278                if (txflags->peer_done_writing &&
 279                    !smc_close_sent_any_close(conn)) {
 280                        /* just shutdown wr done, send close request */
 281                        rc = smc_close_final(conn);
 282                }
 283                /* peer sending PeerConnectionClosed will cause transition */
 284                break;
 285        case SMC_PEERFINCLOSEWAIT:
 286                /* peer sending PeerConnectionClosed will cause transition */
 287                break;
 288        case SMC_PROCESSABORT:
 289                rc = smc_close_abort(conn);
 290                sk->sk_state = SMC_CLOSED;
 291                break;
 292        case SMC_PEERABORTWAIT:
 293                sk->sk_state = SMC_CLOSED;
 294                break;
 295        case SMC_CLOSED:
 296                /* nothing to do, add tracing in future patch */
 297                break;
 298        }
 299
 300        if (old_state != sk->sk_state)
 301                sk->sk_state_change(sk);
 302        return rc;
 303}
 304
 305static void smc_close_passive_abort_received(struct smc_sock *smc)
 306{
 307        struct smc_cdc_conn_state_flags *txflags =
 308                &smc->conn.local_tx_ctrl.conn_state_flags;
 309        struct sock *sk = &smc->sk;
 310
 311        switch (sk->sk_state) {
 312        case SMC_INIT:
 313        case SMC_ACTIVE:
 314        case SMC_APPCLOSEWAIT1:
 315                sk->sk_state = SMC_PROCESSABORT;
 316                sock_put(sk); /* passive closing */
 317                break;
 318        case SMC_APPFINCLOSEWAIT:
 319                sk->sk_state = SMC_PROCESSABORT;
 320                break;
 321        case SMC_PEERCLOSEWAIT1:
 322        case SMC_PEERCLOSEWAIT2:
 323                if (txflags->peer_done_writing &&
 324                    !smc_close_sent_any_close(&smc->conn))
 325                        /* just shutdown, but not yet closed locally */
 326                        sk->sk_state = SMC_PROCESSABORT;
 327                else
 328                        sk->sk_state = SMC_CLOSED;
 329                sock_put(sk); /* passive closing */
 330                break;
 331        case SMC_APPCLOSEWAIT2:
 332        case SMC_PEERFINCLOSEWAIT:
 333                sk->sk_state = SMC_CLOSED;
 334                sock_put(sk); /* passive closing */
 335                break;
 336        case SMC_PEERABORTWAIT:
 337                sk->sk_state = SMC_CLOSED;
 338                break;
 339        case SMC_PROCESSABORT:
 340        /* nothing to do, add tracing in future patch */
 341                break;
 342        }
 343}
 344
 345/* Either some kind of closing has been received: peer_conn_closed,
 346 * peer_conn_abort, or peer_done_writing
 347 * or the link group of the connection terminates abnormally.
 348 */
 349static void smc_close_passive_work(struct work_struct *work)
 350{
 351        struct smc_connection *conn = container_of(work,
 352                                                   struct smc_connection,
 353                                                   close_work);
 354        struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 355        struct smc_cdc_conn_state_flags *rxflags;
 356        bool release_clcsock = false;
 357        struct sock *sk = &smc->sk;
 358        int old_state;
 359
 360        lock_sock(sk);
 361        old_state = sk->sk_state;
 362
 363        rxflags = &conn->local_rx_ctrl.conn_state_flags;
 364        if (rxflags->peer_conn_abort) {
 365                /* peer has not received all data */
 366                smc_close_passive_abort_received(smc);
 367                release_sock(sk);
 368                cancel_delayed_work_sync(&conn->tx_work);
 369                lock_sock(sk);
 370                goto wakeup;
 371        }
 372
 373        switch (sk->sk_state) {
 374        case SMC_INIT:
 375                sk->sk_state = SMC_APPCLOSEWAIT1;
 376                break;
 377        case SMC_ACTIVE:
 378                sk->sk_state = SMC_APPCLOSEWAIT1;
 379                /* postpone sock_put() for passive closing to cover
 380                 * received SEND_SHUTDOWN as well
 381                 */
 382                break;
 383        case SMC_PEERCLOSEWAIT1:
 384                if (rxflags->peer_done_writing)
 385                        sk->sk_state = SMC_PEERCLOSEWAIT2;
 386                fallthrough;
 387                /* to check for closing */
 388        case SMC_PEERCLOSEWAIT2:
 389                if (!smc_cdc_rxed_any_close(conn))
 390                        break;
 391                if (sock_flag(sk, SOCK_DEAD) &&
 392                    smc_close_sent_any_close(conn)) {
 393                        /* smc_release has already been called locally */
 394                        sk->sk_state = SMC_CLOSED;
 395                } else {
 396                        /* just shutdown, but not yet closed locally */
 397                        sk->sk_state = SMC_APPFINCLOSEWAIT;
 398                }
 399                sock_put(sk); /* passive closing */
 400                break;
 401        case SMC_PEERFINCLOSEWAIT:
 402                if (smc_cdc_rxed_any_close(conn)) {
 403                        sk->sk_state = SMC_CLOSED;
 404                        sock_put(sk); /* passive closing */
 405                }
 406                break;
 407        case SMC_APPCLOSEWAIT1:
 408        case SMC_APPCLOSEWAIT2:
 409                /* postpone sock_put() for passive closing to cover
 410                 * received SEND_SHUTDOWN as well
 411                 */
 412                break;
 413        case SMC_APPFINCLOSEWAIT:
 414        case SMC_PEERABORTWAIT:
 415        case SMC_PROCESSABORT:
 416        case SMC_CLOSED:
 417                /* nothing to do, add tracing in future patch */
 418                break;
 419        }
 420
 421wakeup:
 422        sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
 423        sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
 424
 425        if (old_state != sk->sk_state) {
 426                sk->sk_state_change(sk);
 427                if ((sk->sk_state == SMC_CLOSED) &&
 428                    (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
 429                        smc_conn_free(conn);
 430                        if (smc->clcsock)
 431                                release_clcsock = true;
 432                }
 433        }
 434        release_sock(sk);
 435        if (release_clcsock)
 436                smc_clcsock_release(smc);
 437        sock_put(sk); /* sock_hold done by schedulers of close_work */
 438}
 439
 440int smc_close_shutdown_write(struct smc_sock *smc)
 441{
 442        struct smc_connection *conn = &smc->conn;
 443        struct sock *sk = &smc->sk;
 444        int old_state;
 445        long timeout;
 446        int rc = 0;
 447
 448        timeout = current->flags & PF_EXITING ?
 449                  0 : sock_flag(sk, SOCK_LINGER) ?
 450                      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 451
 452        old_state = sk->sk_state;
 453again:
 454        switch (sk->sk_state) {
 455        case SMC_ACTIVE:
 456                smc_close_stream_wait(smc, timeout);
 457                release_sock(sk);
 458                cancel_delayed_work_sync(&conn->tx_work);
 459                lock_sock(sk);
 460                if (sk->sk_state != SMC_ACTIVE)
 461                        goto again;
 462                /* send close wr request */
 463                rc = smc_close_wr(conn);
 464                sk->sk_state = SMC_PEERCLOSEWAIT1;
 465                break;
 466        case SMC_APPCLOSEWAIT1:
 467                /* passive close */
 468                if (!smc_cdc_rxed_any_close(conn))
 469                        smc_close_stream_wait(smc, timeout);
 470                release_sock(sk);
 471                cancel_delayed_work_sync(&conn->tx_work);
 472                lock_sock(sk);
 473                if (sk->sk_state != SMC_APPCLOSEWAIT1)
 474                        goto again;
 475                /* confirm close from peer */
 476                rc = smc_close_wr(conn);
 477                sk->sk_state = SMC_APPCLOSEWAIT2;
 478                break;
 479        case SMC_APPCLOSEWAIT2:
 480        case SMC_PEERFINCLOSEWAIT:
 481        case SMC_PEERCLOSEWAIT1:
 482        case SMC_PEERCLOSEWAIT2:
 483        case SMC_APPFINCLOSEWAIT:
 484        case SMC_PROCESSABORT:
 485        case SMC_PEERABORTWAIT:
 486                /* nothing to do, add tracing in future patch */
 487                break;
 488        }
 489
 490        if (old_state != sk->sk_state)
 491                sk->sk_state_change(sk);
 492        return rc;
 493}
 494
 495/* Initialize close properties on connection establishment. */
 496void smc_close_init(struct smc_sock *smc)
 497{
 498        INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
 499}
 500