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         /* Send out corked data remaining in sndbuf */
  61         smc_tx_pending(&smc->conn);
  62
  63         smc->wait_close_tx_prepared = 1;
  64         add_wait_queue(sk_sleep(sk), &wait);
  65         while (!signal_pending(current) && timeout) {
  66                 int rc;
  67
  68                 rc = sk_wait_event(sk, &timeout,
  69                                    !smc_tx_prepared_sends(&smc->conn) ||
  70                                    READ_ONCE(sk->sk_err) == ECONNABORTED ||
  71                                    READ_ONCE(sk->sk_err) == ECONNRESET ||
  72                                    smc->conn.killed,
  73                                    &wait);
  74                 if (rc)
  75                         break;
  76         }
  77         remove_wait_queue(sk_sleep(sk), &wait);
  78         smc->wait_close_tx_prepared = 0;
  79 }
  80
  81 void smc_close_wake_tx_prepared(struct smc_sock *smc)
  82 {
  83         if (smc->wait_close_tx_prepared)
  84                 /* wake up socket closing */
  85                 smc->sk.sk_state_change(&smc->sk);
  86 }
  87
  88 static int smc_close_wr(struct smc_connection *conn)
  89 {
  90         conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;
  91
  92         return smc_cdc_get_slot_and_msg_send(conn);
  93 }
  94
  95 static int smc_close_final(struct smc_connection *conn)
  96 {
  97         if (atomic_read(&conn->bytes_to_rcv))
  98                 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
  99         else
 100                 conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
 101         if (conn->killed)
 102                 return -EPIPE;
 103
 104         return smc_cdc_get_slot_and_msg_send(conn);
 105 }
 106
 107 int smc_close_abort(struct smc_connection *conn)
 108 {
 109         conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 110
 111         return smc_cdc_get_slot_and_msg_send(conn);
 112 }
 113
 114 static void smc_close_cancel_work(struct smc_sock *smc)
 115 {
 116         struct sock *sk = &smc->sk;
 117
 118         release_sock(sk);
 119         if (cancel_work_sync(&smc->conn.close_work))
 120                 sock_put(sk);
 121         cancel_delayed_work_sync(&smc->conn.tx_work);
 122         lock_sock(sk);
 123 }
 124
 125 /* terminate smc socket abnormally - active abort
 126  * link group is terminated, i.e. RDMA communication no longer possible
 127  */
 128 void smc_close_active_abort(struct smc_sock *smc)
 129 {
 130         struct sock *sk = &smc->sk;
 131         bool release_clcsock = false;
 132
 133         if (sk->sk_state != SMC_INIT && smc->clcsock && smc->clcsock->sk) {
 134                 sk->sk_err = ECONNABORTED;
 135                 if (smc->clcsock && smc->clcsock->sk)
 136                         tcp_abort(smc->clcsock->sk, ECONNABORTED);
 137         }
 138         switch (sk->sk_state) {
 139         case SMC_ACTIVE:
 140         case SMC_APPCLOSEWAIT1:
 141         case SMC_APPCLOSEWAIT2:
 142                 sk->sk_state = SMC_PEERABORTWAIT;
 143                 smc_close_cancel_work(smc);
 144                 if (sk->sk_state != SMC_PEERABORTWAIT)
 145                         break;
 146                 sk->sk_state = SMC_CLOSED;
 147                 sock_put(sk); /* (postponed) passive closing */
 148                 break;
 149         case SMC_PEERCLOSEWAIT1:
 150         case SMC_PEERCLOSEWAIT2:
 151         case SMC_PEERFINCLOSEWAIT:
 152                 sk->sk_state = SMC_PEERABORTWAIT;
 153                 smc_close_cancel_work(smc);
 154                 if (sk->sk_state != SMC_PEERABORTWAIT)
 155                         break;
 156                 sk->sk_state = SMC_CLOSED;
 157                 smc_conn_free(&smc->conn);
 158                 release_clcsock = true;
 159                 sock_put(sk); /* passive closing */
 160                 break;
 161         case SMC_PROCESSABORT:
 162         case SMC_APPFINCLOSEWAIT:
 163                 sk->sk_state = SMC_PEERABORTWAIT;
 164                 smc_close_cancel_work(smc);
 165                 if (sk->sk_state != SMC_PEERABORTWAIT)
 166                         break;
 167                 sk->sk_state = SMC_CLOSED;
 168                 smc_conn_free(&smc->conn);
 169                 release_clcsock = true;
 170                 break;
 171         case SMC_INIT:
 172         case SMC_PEERABORTWAIT:
 173         case SMC_CLOSED:
 174                 break;
 175         }
 176
 177         smc_sock_set_flag(sk, SOCK_DEAD);
 178         sk->sk_state_change(sk);
 179
 180         if (release_clcsock) {
 181                 release_sock(sk);
 182                 smc_clcsock_release(smc);
 183                 lock_sock(sk);
 184         }
 185 }
 186
 187 static inline bool smc_close_sent_any_close(struct smc_connection *conn)
 188 {
 189         return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
 190                conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
 191 }
 192
 193 int smc_close_active(struct smc_sock *smc)
 194 {
 195         struct smc_cdc_conn_state_flags *txflags =
 196                 &smc->conn.local_tx_ctrl.conn_state_flags;
 197         struct smc_connection *conn = &smc->conn;
 198         struct sock *sk = &smc->sk;
 199         int old_state;
 200         long timeout;
 201         int rc = 0;
 202         int rc1 = 0;
 203
 204         timeout = current->flags & PF_EXITING ?
 205                   0 : sock_flag(sk, SOCK_LINGER) ?
 206                       sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 207
 208         old_state = sk->sk_state;
 209 again:
 210         switch (sk->sk_state) {
 211         case SMC_INIT:
 212                 sk->sk_state = SMC_CLOSED;
 213                 break;
 214         case SMC_LISTEN:
 215                 sk->sk_state = SMC_CLOSED;
 216                 sk->sk_state_change(sk); /* wake up accept */
 217                 if (smc->clcsock && smc->clcsock->sk) {
 218                         write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
 219                         smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
 220                                                &smc->clcsk_data_ready);
 221                         smc->clcsock->sk->sk_user_data = NULL;
 222                         write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
 223                         rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
 224                 }
 225                 smc_close_cleanup_listen(sk);
 226                 release_sock(sk);
 227                 flush_work(&smc->tcp_listen_work);
 228                 lock_sock(sk);
 229                 break;
 230         case SMC_ACTIVE:
 231                 smc_close_stream_wait(smc, timeout);
 232                 release_sock(sk);
 233                 cancel_delayed_work_sync(&conn->tx_work);
 234                 lock_sock(sk);
 235                 if (sk->sk_state == SMC_ACTIVE) {
 236                         /* send close request */
 237                         rc = smc_close_final(conn);
 238                         sk->sk_state = SMC_PEERCLOSEWAIT1;
 239
 240                         /* actively shutdown clcsock before peer close it,
 241                          * prevent peer from entering TIME_WAIT state.
 242                          */
 243                         if (smc->clcsock && smc->clcsock->sk) {
 244                                 rc1 = kernel_sock_shutdown(smc->clcsock,
 245                                                            SHUT_RDWR);
 246                                 rc = rc ? rc : rc1;
 247                         }
 248                 } else {
 249                         /* peer event has changed the state */
 250                         goto again;
 251                 }
 252                 break;
 253         case SMC_APPFINCLOSEWAIT:
 254                 /* socket already shutdown wr or both (active close) */
 255                 if (txflags->peer_done_writing &&
 256                     !smc_close_sent_any_close(conn)) {
 257                         /* just shutdown wr done, send close request */
 258                         rc = smc_close_final(conn);
 259                 }
 260                 sk->sk_state = SMC_CLOSED;
 261                 break;
 262         case SMC_APPCLOSEWAIT1:
 263         case SMC_APPCLOSEWAIT2:
 264                 if (!smc_cdc_rxed_any_close(conn))
 265                         smc_close_stream_wait(smc, timeout);
 266                 release_sock(sk);
 267                 cancel_delayed_work_sync(&conn->tx_work);
 268                 lock_sock(sk);
 269                 if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
 270                     sk->sk_state != SMC_APPCLOSEWAIT2)
 271                         goto again;
 272                 /* confirm close from peer */
 273                 rc = smc_close_final(conn);
 274                 if (smc_cdc_rxed_any_close(conn)) {
 275                         /* peer has closed the socket already */
 276                         sk->sk_state = SMC_CLOSED;
 277                         sock_put(sk); /* postponed passive closing */
 278                 } else {
 279                         /* peer has just issued a shutdown write */
 280                         sk->sk_state = SMC_PEERFINCLOSEWAIT;
 281                 }
 282                 break;
 283         case SMC_PEERCLOSEWAIT1:
 284         case SMC_PEERCLOSEWAIT2:
 285                 if (txflags->peer_done_writing &&
 286                     !smc_close_sent_any_close(conn)) {
 287                         /* just shutdown wr done, send close request */
 288                         rc = smc_close_final(conn);
 289                 }
 290                 /* peer sending PeerConnectionClosed will cause transition */
 291                 break;
 292         case SMC_PEERFINCLOSEWAIT:
 293                 /* peer sending PeerConnectionClosed will cause transition */
 294                 break;
 295         case SMC_PROCESSABORT:
 296                 rc = smc_close_abort(conn);
 297                 sk->sk_state = SMC_CLOSED;
 298                 break;
 299         case SMC_PEERABORTWAIT:
 300                 sk->sk_state = SMC_CLOSED;
 301                 break;
 302         case SMC_CLOSED:
 303                 /* nothing to do, add tracing in future patch */
 304                 break;
 305         }
 306
 307         if (old_state != sk->sk_state)
 308                 sk->sk_state_change(sk);
 309         return rc;
 310 }
 311
 312 static void smc_close_passive_abort_received(struct smc_sock *smc)
 313 {
 314         struct smc_cdc_conn_state_flags *txflags =
 315                 &smc->conn.local_tx_ctrl.conn_state_flags;
 316         struct sock *sk = &smc->sk;
 317
 318         switch (sk->sk_state) {
 319         case SMC_INIT:
 320         case SMC_ACTIVE:
 321         case SMC_APPCLOSEWAIT1:
 322                 sk->sk_state = SMC_PROCESSABORT;
 323                 sock_put(sk); /* passive closing */
 324                 break;
 325         case SMC_APPFINCLOSEWAIT:
 326                 sk->sk_state = SMC_PROCESSABORT;
 327                 break;
 328         case SMC_PEERCLOSEWAIT1:
 329         case SMC_PEERCLOSEWAIT2:
 330                 if (txflags->peer_done_writing &&
 331                     !smc_close_sent_any_close(&smc->conn))
 332                         /* just shutdown, but not yet closed locally */
 333                         sk->sk_state = SMC_PROCESSABORT;
 334                 else
 335                         sk->sk_state = SMC_CLOSED;
 336                 sock_put(sk); /* passive closing */
 337                 break;
 338         case SMC_APPCLOSEWAIT2:
 339         case SMC_PEERFINCLOSEWAIT:
 340                 sk->sk_state = SMC_CLOSED;
 341                 sock_put(sk); /* passive closing */
 342                 break;
 343         case SMC_PEERABORTWAIT:
 344                 sk->sk_state = SMC_CLOSED;
 345                 break;
 346         case SMC_PROCESSABORT:
 347         /* nothing to do, add tracing in future patch */
 348                 break;
 349         }
 350 }
 351
 352 /* Either some kind of closing has been received: peer_conn_closed,
 353  * peer_conn_abort, or peer_done_writing
 354  * or the link group of the connection terminates abnormally.
 355  */
 356 static void smc_close_passive_work(struct work_struct *work)
 357 {
 358         struct smc_connection *conn = container_of(work,
 359                                                    struct smc_connection,
 360                                                    close_work);
 361         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 362         struct smc_cdc_conn_state_flags *rxflags;
 363         bool release_clcsock = false;
 364         struct sock *sk = &smc->sk;
 365         int old_state;
 366
 367         lock_sock(sk);
 368         old_state = sk->sk_state;
 369
 370         rxflags = &conn->local_rx_ctrl.conn_state_flags;
 371         if (rxflags->peer_conn_abort) {
 372                 /* peer has not received all data */
 373                 smc_close_passive_abort_received(smc);
 374                 release_sock(sk);
 375                 cancel_delayed_work_sync(&conn->tx_work);
 376                 lock_sock(sk);
 377                 goto wakeup;
 378         }
 379
 380         switch (sk->sk_state) {
 381         case SMC_INIT:
 382                 sk->sk_state = SMC_APPCLOSEWAIT1;
 383                 break;
 384         case SMC_ACTIVE:
 385                 sk->sk_state = SMC_APPCLOSEWAIT1;
 386                 /* postpone sock_put() for passive closing to cover
 387                  * received SEND_SHUTDOWN as well
 388                  */
 389                 break;
 390         case SMC_PEERCLOSEWAIT1:
 391                 if (rxflags->peer_done_writing)
 392                         sk->sk_state = SMC_PEERCLOSEWAIT2;
 393                 fallthrough;
 394                 /* to check for closing */
 395         case SMC_PEERCLOSEWAIT2:
 396                 if (!smc_cdc_rxed_any_close(conn))
 397                         break;
 398                 if (sock_flag(sk, SOCK_DEAD) &&
 399                     smc_close_sent_any_close(conn)) {
 400                         /* smc_release has already been called locally */
 401                         sk->sk_state = SMC_CLOSED;
 402                 } else {
 403                         /* just shutdown, but not yet closed locally */
 404                         sk->sk_state = SMC_APPFINCLOSEWAIT;
 405                 }
 406                 sock_put(sk); /* passive closing */
 407                 break;
 408         case SMC_PEERFINCLOSEWAIT:
 409                 if (smc_cdc_rxed_any_close(conn)) {
 410                         sk->sk_state = SMC_CLOSED;
 411                         sock_put(sk); /* passive closing */
 412                 }
 413                 break;
 414         case SMC_APPCLOSEWAIT1:
 415         case SMC_APPCLOSEWAIT2:
 416                 /* postpone sock_put() for passive closing to cover
 417                  * received SEND_SHUTDOWN as well
 418                  */
 419                 break;
 420         case SMC_APPFINCLOSEWAIT:
 421         case SMC_PEERABORTWAIT:
 422         case SMC_PROCESSABORT:
 423         case SMC_CLOSED:
 424                 /* nothing to do, add tracing in future patch */
 425                 break;
 426         }
 427
 428 wakeup:
 429         sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
 430         sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
 431
 432         if (old_state != sk->sk_state) {
 433                 sk->sk_state_change(sk);
 434                 if ((sk->sk_state == SMC_CLOSED) &&
 435                     (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
 436                         smc_conn_free(conn);
 437                         if (smc->clcsock)
 438                                 release_clcsock = true;
 439                 }
 440         }
 441         release_sock(sk);
 442         if (release_clcsock)
 443                 smc_clcsock_release(smc);
 444         sock_put(sk); /* sock_hold done by schedulers of close_work */
 445 }
 446
 447 int smc_close_shutdown_write(struct smc_sock *smc)
 448 {
 449         struct smc_connection *conn = &smc->conn;
 450         struct sock *sk = &smc->sk;
 451         int old_state;
 452         long timeout;
 453         int rc = 0;
 454
 455         timeout = current->flags & PF_EXITING ?
 456                   0 : sock_flag(sk, SOCK_LINGER) ?
 457                       sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 458
 459         old_state = sk->sk_state;
 460 again:
 461         switch (sk->sk_state) {
 462         case SMC_ACTIVE:
 463                 smc_close_stream_wait(smc, timeout);
 464                 release_sock(sk);
 465                 cancel_delayed_work_sync(&conn->tx_work);
 466                 lock_sock(sk);
 467                 if (sk->sk_state != SMC_ACTIVE)
 468                         goto again;
 469                 /* send close wr request */
 470                 rc = smc_close_wr(conn);
 471                 sk->sk_state = SMC_PEERCLOSEWAIT1;
 472                 break;
 473         case SMC_APPCLOSEWAIT1:
 474                 /* passive close */
 475                 if (!smc_cdc_rxed_any_close(conn))
 476                         smc_close_stream_wait(smc, timeout);
 477                 release_sock(sk);
 478                 cancel_delayed_work_sync(&conn->tx_work);
 479                 lock_sock(sk);
 480                 if (sk->sk_state != SMC_APPCLOSEWAIT1)
 481                         goto again;
 482                 /* confirm close from peer */
 483                 rc = smc_close_wr(conn);
 484                 sk->sk_state = SMC_APPCLOSEWAIT2;
 485                 break;
 486         case SMC_APPCLOSEWAIT2:
 487         case SMC_PEERFINCLOSEWAIT:
 488         case SMC_PEERCLOSEWAIT1:
 489         case SMC_PEERCLOSEWAIT2:
 490         case SMC_APPFINCLOSEWAIT:
 491         case SMC_PROCESSABORT:
 492         case SMC_PEERABORTWAIT:
 493                 /* nothing to do, add tracing in future patch */
 494                 break;
 495         }
 496
 497         if (old_state != sk->sk_state)
 498                 sk->sk_state_change(sk);
 499         return rc;
 500 }
 501
 502 /* Initialize close properties on connection establishment. */
 503 void smc_close_init(struct smc_sock *smc)
 504 {
 505         INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
 506 }