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         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
 199         timeout = current->flags & PF_EXITING ?
 200                   0 : sock_flag(sk, SOCK_LINGER) ?
 201                       sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 202
 203         old_state = sk->sk_state;
 204 again:
 205         switch (sk->sk_state) {
 206         case SMC_INIT:
 207                 sk->sk_state = SMC_CLOSED;
 208                 break;
 209         case SMC_LISTEN:
 210                 sk->sk_state = SMC_CLOSED;
 211                 sk->sk_state_change(sk); /* wake up accept */
 212                 if (smc->clcsock && smc->clcsock->sk) {
 213                         smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
 214                         smc->clcsock->sk->sk_user_data = NULL;
 215                         rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
 216                 }
 217                 smc_close_cleanup_listen(sk);
 218                 release_sock(sk);
 219                 flush_work(&smc->tcp_listen_work);
 220                 lock_sock(sk);
 221                 break;
 222         case SMC_ACTIVE:
 223                 smc_close_stream_wait(smc, timeout);
 224                 release_sock(sk);
 225                 cancel_delayed_work_sync(&conn->tx_work);
 226                 lock_sock(sk);
 227                 if (sk->sk_state == SMC_ACTIVE) {
 228                         /* send close request */
 229                         rc = smc_close_final(conn);
 230                         sk->sk_state = SMC_PEERCLOSEWAIT1;
 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                 }
 243                 sk->sk_state = SMC_CLOSED;
 244                 break;
 245         case SMC_APPCLOSEWAIT1:
 246         case SMC_APPCLOSEWAIT2:
 247                 if (!smc_cdc_rxed_any_close(conn))
 248                         smc_close_stream_wait(smc, timeout);
 249                 release_sock(sk);
 250                 cancel_delayed_work_sync(&conn->tx_work);
 251                 lock_sock(sk);
 252                 if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
 253                     sk->sk_state != SMC_APPCLOSEWAIT2)
 254                         goto again;
 255                 /* confirm close from peer */
 256                 rc = smc_close_final(conn);
 257                 if (smc_cdc_rxed_any_close(conn)) {
 258                         /* peer has closed the socket already */
 259                         sk->sk_state = SMC_CLOSED;
 260                         sock_put(sk); /* postponed passive closing */
 261                 } else {
 262                         /* peer has just issued a shutdown write */
 263                         sk->sk_state = SMC_PEERFINCLOSEWAIT;
 264                 }
 265                 break;
 266         case SMC_PEERCLOSEWAIT1:
 267         case SMC_PEERCLOSEWAIT2:
 268                 if (txflags->peer_done_writing &&
 269                     !smc_close_sent_any_close(conn)) {
 270                         /* just shutdown wr done, send close request */
 271                         rc = smc_close_final(conn);
 272                 }
 273                 /* peer sending PeerConnectionClosed will cause transition */
 274                 break;
 275         case SMC_PEERFINCLOSEWAIT:
 276                 /* peer sending PeerConnectionClosed will cause transition */
 277                 break;
 278         case SMC_PROCESSABORT:
 279                 rc = smc_close_abort(conn);
 280                 sk->sk_state = SMC_CLOSED;
 281                 break;
 282         case SMC_PEERABORTWAIT:
 283                 sk->sk_state = SMC_CLOSED;
 284                 break;
 285         case SMC_CLOSED:
 286                 /* nothing to do, add tracing in future patch */
 287                 break;
 288         }
 289
 290         if (old_state != sk->sk_state)
 291                 sk->sk_state_change(sk);
 292         return rc;
 293 }
 294
 295 static void smc_close_passive_abort_received(struct smc_sock *smc)
 296 {
 297         struct smc_cdc_conn_state_flags *txflags =
 298                 &smc->conn.local_tx_ctrl.conn_state_flags;
 299         struct sock *sk = &smc->sk;
 300
 301         switch (sk->sk_state) {
 302         case SMC_INIT:
 303         case SMC_ACTIVE:
 304         case SMC_APPCLOSEWAIT1:
 305                 sk->sk_state = SMC_PROCESSABORT;
 306                 sock_put(sk); /* passive closing */
 307                 break;
 308         case SMC_APPFINCLOSEWAIT:
 309                 sk->sk_state = SMC_PROCESSABORT;
 310                 break;
 311         case SMC_PEERCLOSEWAIT1:
 312         case SMC_PEERCLOSEWAIT2:
 313                 if (txflags->peer_done_writing &&
 314                     !smc_close_sent_any_close(&smc->conn))
 315                         /* just shutdown, but not yet closed locally */
 316                         sk->sk_state = SMC_PROCESSABORT;
 317                 else
 318                         sk->sk_state = SMC_CLOSED;
 319                 sock_put(sk); /* passive closing */
 320                 break;
 321         case SMC_APPCLOSEWAIT2:
 322         case SMC_PEERFINCLOSEWAIT:
 323                 sk->sk_state = SMC_CLOSED;
 324                 sock_put(sk); /* passive closing */
 325                 break;
 326         case SMC_PEERABORTWAIT:
 327                 sk->sk_state = SMC_CLOSED;
 328                 break;
 329         case SMC_PROCESSABORT:
 330         /* nothing to do, add tracing in future patch */
 331                 break;
 332         }
 333 }
 334
 335 /* Either some kind of closing has been received: peer_conn_closed,
 336  * peer_conn_abort, or peer_done_writing
 337  * or the link group of the connection terminates abnormally.
 338  */
 339 static void smc_close_passive_work(struct work_struct *work)
 340 {
 341         struct smc_connection *conn = container_of(work,
 342                                                    struct smc_connection,
 343                                                    close_work);
 344         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 345         struct smc_cdc_conn_state_flags *rxflags;
 346         bool release_clcsock = false;
 347         struct sock *sk = &smc->sk;
 348         int old_state;
 349
 350         lock_sock(sk);
 351         old_state = sk->sk_state;
 352
 353         rxflags = &conn->local_rx_ctrl.conn_state_flags;
 354         if (rxflags->peer_conn_abort) {
 355                 /* peer has not received all data */
 356                 smc_close_passive_abort_received(smc);
 357                 release_sock(&smc->sk);
 358                 cancel_delayed_work_sync(&conn->tx_work);
 359                 lock_sock(&smc->sk);
 360                 goto wakeup;
 361         }
 362
 363         switch (sk->sk_state) {
 364         case SMC_INIT:
 365                 sk->sk_state = SMC_APPCLOSEWAIT1;
 366                 break;
 367         case SMC_ACTIVE:
 368                 sk->sk_state = SMC_APPCLOSEWAIT1;
 369                 /* postpone sock_put() for passive closing to cover
 370                  * received SEND_SHUTDOWN as well
 371                  */
 372                 break;
 373         case SMC_PEERCLOSEWAIT1:
 374                 if (rxflags->peer_done_writing)
 375                         sk->sk_state = SMC_PEERCLOSEWAIT2;
 376                 fallthrough;
 377                 /* to check for closing */
 378         case SMC_PEERCLOSEWAIT2:
 379                 if (!smc_cdc_rxed_any_close(conn))
 380                         break;
 381                 if (sock_flag(sk, SOCK_DEAD) &&
 382                     smc_close_sent_any_close(conn)) {
 383                         /* smc_release has already been called locally */
 384                         sk->sk_state = SMC_CLOSED;
 385                 } else {
 386                         /* just shutdown, but not yet closed locally */
 387                         sk->sk_state = SMC_APPFINCLOSEWAIT;
 388                 }
 389                 sock_put(sk); /* passive closing */
 390                 break;
 391         case SMC_PEERFINCLOSEWAIT:
 392                 if (smc_cdc_rxed_any_close(conn)) {
 393                         sk->sk_state = SMC_CLOSED;
 394                         sock_put(sk); /* passive closing */
 395                 }
 396                 break;
 397         case SMC_APPCLOSEWAIT1:
 398         case SMC_APPCLOSEWAIT2:
 399                 /* postpone sock_put() for passive closing to cover
 400                  * received SEND_SHUTDOWN as well
 401                  */
 402                 break;
 403         case SMC_APPFINCLOSEWAIT:
 404         case SMC_PEERABORTWAIT:
 405         case SMC_PROCESSABORT:
 406         case SMC_CLOSED:
 407                 /* nothing to do, add tracing in future patch */
 408                 break;
 409         }
 410
 411 wakeup:
 412         sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
 413         sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
 414
 415         if (old_state != sk->sk_state) {
 416                 sk->sk_state_change(sk);
 417                 if ((sk->sk_state == SMC_CLOSED) &&
 418                     (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
 419                         smc_conn_free(conn);
 420                         if (smc->clcsock)
 421                                 release_clcsock = true;
 422                 }
 423         }
 424         release_sock(sk);
 425         if (release_clcsock)
 426                 smc_clcsock_release(smc);
 427         sock_put(sk); /* sock_hold done by schedulers of close_work */
 428 }
 429
 430 int smc_close_shutdown_write(struct smc_sock *smc)
 431 {
 432         struct smc_connection *conn = &smc->conn;
 433         struct sock *sk = &smc->sk;
 434         int old_state;
 435         long timeout;
 436         int rc = 0;
 437
 438         timeout = current->flags & PF_EXITING ?
 439                   0 : sock_flag(sk, SOCK_LINGER) ?
 440                       sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 441
 442         old_state = sk->sk_state;
 443 again:
 444         switch (sk->sk_state) {
 445         case SMC_ACTIVE:
 446                 smc_close_stream_wait(smc, timeout);
 447                 release_sock(sk);
 448                 cancel_delayed_work_sync(&conn->tx_work);
 449                 lock_sock(sk);
 450                 if (sk->sk_state != SMC_ACTIVE)
 451                         goto again;
 452                 /* send close wr request */
 453                 rc = smc_close_wr(conn);
 454                 sk->sk_state = SMC_PEERCLOSEWAIT1;
 455                 break;
 456         case SMC_APPCLOSEWAIT1:
 457                 /* passive close */
 458                 if (!smc_cdc_rxed_any_close(conn))
 459                         smc_close_stream_wait(smc, timeout);
 460                 release_sock(sk);
 461                 cancel_delayed_work_sync(&conn->tx_work);
 462                 lock_sock(sk);
 463                 if (sk->sk_state != SMC_APPCLOSEWAIT1)
 464                         goto again;
 465                 /* confirm close from peer */
 466                 rc = smc_close_wr(conn);
 467                 sk->sk_state = SMC_APPCLOSEWAIT2;
 468                 break;
 469         case SMC_APPCLOSEWAIT2:
 470         case SMC_PEERFINCLOSEWAIT:
 471         case SMC_PEERCLOSEWAIT1:
 472         case SMC_PEERCLOSEWAIT2:
 473         case SMC_APPFINCLOSEWAIT:
 474         case SMC_PROCESSABORT:
 475         case SMC_PEERABORTWAIT:
 476                 /* nothing to do, add tracing in future patch */
 477                 break;
 478         }
 479
 480         if (old_state != sk->sk_state)
 481                 sk->sk_state_change(sk);
 482         return rc;
 483 }
 484
 485 /* Initialize close properties on connection establishment. */
 486 void smc_close_init(struct smc_sock *smc)
 487 {
 488         INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
 489 }