net/smc/smc_close.c

   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 */
  24 void 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
  39 static 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 */
  49 static 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
  78 void 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
  85 static 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
  92 static 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
 104 int 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
 111 static 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  */
 124 void 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
 183 static 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
 189 int 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;
 205 again:
 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
 305 static 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  */
 349 static 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(&smc->sk);
 368                 cancel_delayed_work_sync(&conn->tx_work);
 369                 lock_sock(&smc->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
 421 wakeup:
 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
 440 int 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;
 453 again:
 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. */
 496 void smc_close_init(struct smc_sock *smc)
 497 {
 498         INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
 499 }