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