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