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
  17 #include "smc.h"
  18 #include "smc_tx.h"
  19 #include "smc_cdc.h"
  20 #include "smc_close.h"
  21
  22 #define SMC_CLOSE_WAIT_LISTEN_CLCSOCK_TIME      (5 * HZ)
  23
  24 /* release the clcsock that is assigned to the smc_sock */
  25 void smc_clcsock_release(struct smc_sock *smc)
  26 {
  27         struct socket *tcp;
  28
  29         if (smc->listen_smc && current_work() != &smc->smc_listen_work)
  30                 cancel_work_sync(&smc->smc_listen_work);
  31         mutex_lock(&smc->clcsock_release_lock);
  32         if (smc->clcsock) {
  33                 tcp = smc->clcsock;
  34                 smc->clcsock = NULL;
  35                 sock_release(tcp);
  36         }
  37         mutex_unlock(&smc->clcsock_release_lock);
  38 }
  39
  40 static void smc_close_cleanup_listen(struct sock *parent)
  41 {
  42         struct sock *sk;
  43
  44         /* Close non-accepted connections */
  45         while ((sk = smc_accept_dequeue(parent, NULL)))
  46                 smc_close_non_accepted(sk);
  47 }
  48
  49 /* wait for sndbuf data being transmitted */
  50 static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
  51 {
  52         DEFINE_WAIT_FUNC(wait, woken_wake_function);
  53         struct sock *sk = &smc->sk;
  54
  55         if (!timeout)
  56                 return;
  57
  58         if (!smc_tx_prepared_sends(&smc->conn))
  59                 return;
  60
  61         smc->wait_close_tx_prepared = 1;
  62         add_wait_queue(sk_sleep(sk), &wait);
  63         while (!signal_pending(current) && timeout) {
  64                 int rc;
  65
  66                 rc = sk_wait_event(sk, &timeout,
  67                                    !smc_tx_prepared_sends(&smc->conn) ||
  68                                    (sk->sk_err == ECONNABORTED) ||
  69                                    (sk->sk_err == ECONNRESET),
  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
  99         return smc_cdc_get_slot_and_msg_send(conn);
 100 }
 101
 102 static int smc_close_abort(struct smc_connection *conn)
 103 {
 104         conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 105
 106         return smc_cdc_get_slot_and_msg_send(conn);
 107 }
 108
 109 /* terminate smc socket abnormally - active abort
 110  * link group is terminated, i.e. RDMA communication no longer possible
 111  */
 112 static void smc_close_active_abort(struct smc_sock *smc)
 113 {
 114         struct sock *sk = &smc->sk;
 115
 116         struct smc_cdc_conn_state_flags *txflags =
 117                 &smc->conn.local_tx_ctrl.conn_state_flags;
 118
 119         if (sk->sk_state != SMC_INIT && smc->clcsock && smc->clcsock->sk) {
 120                 sk->sk_err = ECONNABORTED;
 121                 if (smc->clcsock && smc->clcsock->sk) {
 122                         smc->clcsock->sk->sk_err = ECONNABORTED;
 123                         smc->clcsock->sk->sk_state_change(smc->clcsock->sk);
 124                 }
 125         }
 126         switch (sk->sk_state) {
 127         case SMC_ACTIVE:
 128                 sk->sk_state = SMC_PEERABORTWAIT;
 129                 release_sock(sk);
 130                 cancel_delayed_work_sync(&smc->conn.tx_work);
 131                 lock_sock(sk);
 132                 sock_put(sk); /* passive closing */
 133                 break;
 134         case SMC_APPCLOSEWAIT1:
 135         case SMC_APPCLOSEWAIT2:
 136                 if (!smc_cdc_rxed_any_close(&smc->conn))
 137                         sk->sk_state = SMC_PEERABORTWAIT;
 138                 else
 139                         sk->sk_state = SMC_CLOSED;
 140                 release_sock(sk);
 141                 cancel_delayed_work_sync(&smc->conn.tx_work);
 142                 lock_sock(sk);
 143                 break;
 144         case SMC_PEERCLOSEWAIT1:
 145         case SMC_PEERCLOSEWAIT2:
 146                 if (!txflags->peer_conn_closed) {
 147                         /* just SHUTDOWN_SEND done */
 148                         sk->sk_state = SMC_PEERABORTWAIT;
 149                 } else {
 150                         sk->sk_state = SMC_CLOSED;
 151                 }
 152                 sock_put(sk); /* passive closing */
 153                 break;
 154         case SMC_PROCESSABORT:
 155         case SMC_APPFINCLOSEWAIT:
 156                 sk->sk_state = SMC_CLOSED;
 157                 break;
 158         case SMC_PEERFINCLOSEWAIT:
 159                 sock_put(sk); /* passive closing */
 160                 break;
 161         case SMC_INIT:
 162         case SMC_PEERABORTWAIT:
 163         case SMC_CLOSED:
 164                 break;
 165         }
 166
 167         sock_set_flag(sk, SOCK_DEAD);
 168         sk->sk_state_change(sk);
 169 }
 170
 171 static inline bool smc_close_sent_any_close(struct smc_connection *conn)
 172 {
 173         return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
 174                conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
 175 }
 176
 177 int smc_close_active(struct smc_sock *smc)
 178 {
 179         struct smc_cdc_conn_state_flags *txflags =
 180                 &smc->conn.local_tx_ctrl.conn_state_flags;
 181         struct smc_connection *conn = &smc->conn;
 182         struct sock *sk = &smc->sk;
 183         int old_state;
 184         long timeout;
 185         int rc = 0;
 186         int rc1 = 0;
 187
 188         timeout = current->flags & PF_EXITING ?
 189                   0 : sock_flag(sk, SOCK_LINGER) ?
 190                       sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 191
 192         old_state = sk->sk_state;
 193 again:
 194         switch (sk->sk_state) {
 195         case SMC_INIT:
 196                 sk->sk_state = SMC_CLOSED;
 197                 break;
 198         case SMC_LISTEN:
 199                 sk->sk_state = SMC_CLOSED;
 200                 sk->sk_state_change(sk); /* wake up accept */
 201                 if (smc->clcsock && smc->clcsock->sk) {
 202                         rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
 203                         /* wake up kernel_accept of smc_tcp_listen_worker */
 204                         smc->clcsock->sk->sk_data_ready(smc->clcsock->sk);
 205                 }
 206                 smc_close_cleanup_listen(sk);
 207                 release_sock(sk);
 208                 flush_work(&smc->tcp_listen_work);
 209                 lock_sock(sk);
 210                 break;
 211         case SMC_ACTIVE:
 212                 smc_close_stream_wait(smc, timeout);
 213                 release_sock(sk);
 214                 cancel_delayed_work_sync(&conn->tx_work);
 215                 lock_sock(sk);
 216                 if (sk->sk_state == SMC_ACTIVE) {
 217                         /* send close request */
 218                         rc = smc_close_final(conn);
 219                         if (rc)
 220                                 break;
 221                         sk->sk_state = SMC_PEERCLOSEWAIT1;
 222
 223                         /* actively shutdown clcsock before peer close it,
 224                          * prevent peer from entering TIME_WAIT state.
 225                          */
 226                         if (smc->clcsock && smc->clcsock->sk) {
 227                                 rc1 = kernel_sock_shutdown(smc->clcsock,
 228                                                            SHUT_RDWR);
 229                                 rc = rc ? rc : rc1;
 230                         }
 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                         if (rc)
 243                                 break;
 244                 }
 245                 sk->sk_state = SMC_CLOSED;
 246                 break;
 247         case SMC_APPCLOSEWAIT1:
 248         case SMC_APPCLOSEWAIT2:
 249                 if (!smc_cdc_rxed_any_close(conn))
 250                         smc_close_stream_wait(smc, timeout);
 251                 release_sock(sk);
 252                 cancel_delayed_work_sync(&conn->tx_work);
 253                 lock_sock(sk);
 254                 if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
 255                     sk->sk_state != SMC_APPCLOSEWAIT2)
 256                         goto again;
 257                 /* confirm close from peer */
 258                 rc = smc_close_final(conn);
 259                 if (rc)
 260                         break;
 261                 if (smc_cdc_rxed_any_close(conn)) {
 262                         /* peer has closed the socket already */
 263                         sk->sk_state = SMC_CLOSED;
 264                         sock_put(sk); /* postponed passive closing */
 265                 } else {
 266                         /* peer has just issued a shutdown write */
 267                         sk->sk_state = SMC_PEERFINCLOSEWAIT;
 268                 }
 269                 break;
 270         case SMC_PEERCLOSEWAIT1:
 271         case SMC_PEERCLOSEWAIT2:
 272                 if (txflags->peer_done_writing &&
 273                     !smc_close_sent_any_close(conn)) {
 274                         /* just shutdown wr done, send close request */
 275                         rc = smc_close_final(conn);
 276                         if (rc)
 277                                 break;
 278                 }
 279                 /* peer sending PeerConnectionClosed will cause transition */
 280                 break;
 281         case SMC_PEERFINCLOSEWAIT:
 282                 /* peer sending PeerConnectionClosed will cause transition */
 283                 break;
 284         case SMC_PROCESSABORT:
 285                 smc_close_abort(conn);
 286                 sk->sk_state = SMC_CLOSED;
 287                 break;
 288         case SMC_PEERABORTWAIT:
 289         case SMC_CLOSED:
 290                 /* nothing to do, add tracing in future patch */
 291                 break;
 292         }
 293
 294         if (old_state != sk->sk_state)
 295                 sk->sk_state_change(sk);
 296         return rc;
 297 }
 298
 299 static void smc_close_passive_abort_received(struct smc_sock *smc)
 300 {
 301         struct smc_cdc_conn_state_flags *txflags =
 302                 &smc->conn.local_tx_ctrl.conn_state_flags;
 303         struct sock *sk = &smc->sk;
 304
 305         switch (sk->sk_state) {
 306         case SMC_INIT:
 307         case SMC_ACTIVE:
 308         case SMC_APPCLOSEWAIT1:
 309                 sk->sk_state = SMC_PROCESSABORT;
 310                 sock_put(sk); /* passive closing */
 311                 break;
 312         case SMC_APPFINCLOSEWAIT:
 313                 sk->sk_state = SMC_PROCESSABORT;
 314                 break;
 315         case SMC_PEERCLOSEWAIT1:
 316         case SMC_PEERCLOSEWAIT2:
 317                 if (txflags->peer_done_writing &&
 318                     !smc_close_sent_any_close(&smc->conn))
 319                         /* just shutdown, but not yet closed locally */
 320                         sk->sk_state = SMC_PROCESSABORT;
 321                 else
 322                         sk->sk_state = SMC_CLOSED;
 323                 sock_put(sk); /* passive closing */
 324                 break;
 325         case SMC_APPCLOSEWAIT2:
 326         case SMC_PEERFINCLOSEWAIT:
 327                 sk->sk_state = SMC_CLOSED;
 328                 sock_put(sk); /* passive closing */
 329                 break;
 330         case SMC_PEERABORTWAIT:
 331                 sk->sk_state = SMC_CLOSED;
 332                 break;
 333         case SMC_PROCESSABORT:
 334         /* nothing to do, add tracing in future patch */
 335                 break;
 336         }
 337 }
 338
 339 /* Either some kind of closing has been received: peer_conn_closed,
 340  * peer_conn_abort, or peer_done_writing
 341  * or the link group of the connection terminates abnormally.
 342  */
 343 static void smc_close_passive_work(struct work_struct *work)
 344 {
 345         struct smc_connection *conn = container_of(work,
 346                                                    struct smc_connection,
 347                                                    close_work);
 348         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 349         struct smc_cdc_conn_state_flags *rxflags;
 350         bool release_clcsock = false;
 351         struct sock *sk = &smc->sk;
 352         int old_state;
 353
 354         lock_sock(sk);
 355         old_state = sk->sk_state;
 356
 357         if (!conn->alert_token_local) {
 358                 /* abnormal termination */
 359                 smc_close_active_abort(smc);
 360                 goto wakeup;
 361         }
 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                 /* fall through */
 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                 if (rc)
 465                         break;
 466                 sk->sk_state = SMC_PEERCLOSEWAIT1;
 467                 break;
 468         case SMC_APPCLOSEWAIT1:
 469                 /* passive close */
 470                 if (!smc_cdc_rxed_any_close(conn))
 471                         smc_close_stream_wait(smc, timeout);
 472                 release_sock(sk);
 473                 cancel_delayed_work_sync(&conn->tx_work);
 474                 lock_sock(sk);
 475                 if (sk->sk_state != SMC_APPCLOSEWAIT1)
 476                         goto again;
 477                 /* confirm close from peer */
 478                 rc = smc_close_wr(conn);
 479                 if (rc)
 480                         break;
 481                 sk->sk_state = SMC_APPCLOSEWAIT2;
 482                 break;
 483         case SMC_APPCLOSEWAIT2:
 484         case SMC_PEERFINCLOSEWAIT:
 485         case SMC_PEERCLOSEWAIT1:
 486         case SMC_PEERCLOSEWAIT2:
 487         case SMC_APPFINCLOSEWAIT:
 488         case SMC_PROCESSABORT:
 489         case SMC_PEERABORTWAIT:
 490                 /* nothing to do, add tracing in future patch */
 491                 break;
 492         }
 493
 494         if (old_state != sk->sk_state)
 495                 sk->sk_state_change(sk);
 496         return rc;
 497 }
 498
 499 /* Initialize close properties on connection establishment. */
 500 void smc_close_init(struct smc_sock *smc)
 501 {
 502         INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
 503 }