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
  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 static void smc_close_cleanup_listen(struct sock *parent)
  25 {
  26         struct sock *sk;
  27
  28         /* Close non-accepted connections */
  29         while ((sk = smc_accept_dequeue(parent, NULL)))
  30                 smc_close_non_accepted(sk);
  31 }
  32
  33 /* wait for sndbuf data being transmitted */
  34 static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
  35 {
  36         DEFINE_WAIT_FUNC(wait, woken_wake_function);
  37         struct sock *sk = &smc->sk;
  38
  39         if (!timeout)
  40                 return;
  41
  42         if (!smc_tx_prepared_sends(&smc->conn))
  43                 return;
  44
  45         smc->wait_close_tx_prepared = 1;
  46         add_wait_queue(sk_sleep(sk), &wait);
  47         while (!signal_pending(current) && timeout) {
  48                 int rc;
  49
  50                 rc = sk_wait_event(sk, &timeout,
  51                                    !smc_tx_prepared_sends(&smc->conn) ||
  52                                    (sk->sk_err == ECONNABORTED) ||
  53                                    (sk->sk_err == ECONNRESET),
  54                                    &wait);
  55                 if (rc)
  56                         break;
  57         }
  58         remove_wait_queue(sk_sleep(sk), &wait);
  59         smc->wait_close_tx_prepared = 0;
  60 }
  61
  62 void smc_close_wake_tx_prepared(struct smc_sock *smc)
  63 {
  64         if (smc->wait_close_tx_prepared)
  65                 /* wake up socket closing */
  66                 smc->sk.sk_state_change(&smc->sk);
  67 }
  68
  69 static int smc_close_wr(struct smc_connection *conn)
  70 {
  71         conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;
  72
  73         return smc_cdc_get_slot_and_msg_send(conn);
  74 }
  75
  76 static int smc_close_final(struct smc_connection *conn)
  77 {
  78         if (atomic_read(&conn->bytes_to_rcv))
  79                 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
  80         else
  81                 conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
  82
  83         return smc_cdc_get_slot_and_msg_send(conn);
  84 }
  85
  86 static int smc_close_abort(struct smc_connection *conn)
  87 {
  88         conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
  89
  90         return smc_cdc_get_slot_and_msg_send(conn);
  91 }
  92
  93 /* terminate smc socket abnormally - active abort
  94  * link group is terminated, i.e. RDMA communication no longer possible
  95  */
  96 static void smc_close_active_abort(struct smc_sock *smc)
  97 {
  98         struct sock *sk = &smc->sk;
  99
 100         struct smc_cdc_conn_state_flags *txflags =
 101                 &smc->conn.local_tx_ctrl.conn_state_flags;
 102
 103         if (sk->sk_state != SMC_INIT && smc->clcsock && smc->clcsock->sk) {
 104                 sk->sk_err = ECONNABORTED;
 105                 if (smc->clcsock && smc->clcsock->sk) {
 106                         smc->clcsock->sk->sk_err = ECONNABORTED;
 107                         smc->clcsock->sk->sk_state_change(smc->clcsock->sk);
 108                 }
 109         }
 110         switch (sk->sk_state) {
 111         case SMC_ACTIVE:
 112                 sk->sk_state = SMC_PEERABORTWAIT;
 113                 release_sock(sk);
 114                 cancel_delayed_work_sync(&smc->conn.tx_work);
 115                 lock_sock(sk);
 116                 sock_put(sk); /* passive closing */
 117                 break;
 118         case SMC_APPCLOSEWAIT1:
 119         case SMC_APPCLOSEWAIT2:
 120                 if (!smc_cdc_rxed_any_close(&smc->conn))
 121                         sk->sk_state = SMC_PEERABORTWAIT;
 122                 else
 123                         sk->sk_state = SMC_CLOSED;
 124                 release_sock(sk);
 125                 cancel_delayed_work_sync(&smc->conn.tx_work);
 126                 lock_sock(sk);
 127                 break;
 128         case SMC_PEERCLOSEWAIT1:
 129         case SMC_PEERCLOSEWAIT2:
 130                 if (!txflags->peer_conn_closed) {
 131                         /* just SHUTDOWN_SEND done */
 132                         sk->sk_state = SMC_PEERABORTWAIT;
 133                 } else {
 134                         sk->sk_state = SMC_CLOSED;
 135                 }
 136                 sock_put(sk); /* passive closing */
 137                 break;
 138         case SMC_PROCESSABORT:
 139         case SMC_APPFINCLOSEWAIT:
 140                 sk->sk_state = SMC_CLOSED;
 141                 break;
 142         case SMC_PEERFINCLOSEWAIT:
 143                 sock_put(sk); /* passive closing */
 144                 break;
 145         case SMC_INIT:
 146         case SMC_PEERABORTWAIT:
 147         case SMC_CLOSED:
 148                 break;
 149         }
 150
 151         sock_set_flag(sk, SOCK_DEAD);
 152         sk->sk_state_change(sk);
 153 }
 154
 155 static inline bool smc_close_sent_any_close(struct smc_connection *conn)
 156 {
 157         return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
 158                conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
 159 }
 160
 161 int smc_close_active(struct smc_sock *smc)
 162 {
 163         struct smc_cdc_conn_state_flags *txflags =
 164                 &smc->conn.local_tx_ctrl.conn_state_flags;
 165         struct smc_connection *conn = &smc->conn;
 166         struct sock *sk = &smc->sk;
 167         int old_state;
 168         long timeout;
 169         int rc = 0;
 170
 171         timeout = current->flags & PF_EXITING ?
 172                   0 : sock_flag(sk, SOCK_LINGER) ?
 173                       sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 174
 175         old_state = sk->sk_state;
 176 again:
 177         switch (sk->sk_state) {
 178         case SMC_INIT:
 179                 sk->sk_state = SMC_CLOSED;
 180                 break;
 181         case SMC_LISTEN:
 182                 sk->sk_state = SMC_CLOSED;
 183                 sk->sk_state_change(sk); /* wake up accept */
 184                 if (smc->clcsock && smc->clcsock->sk) {
 185                         rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
 186                         /* wake up kernel_accept of smc_tcp_listen_worker */
 187                         smc->clcsock->sk->sk_data_ready(smc->clcsock->sk);
 188                 }
 189                 smc_close_cleanup_listen(sk);
 190                 release_sock(sk);
 191                 flush_work(&smc->tcp_listen_work);
 192                 lock_sock(sk);
 193                 break;
 194         case SMC_ACTIVE:
 195                 smc_close_stream_wait(smc, timeout);
 196                 release_sock(sk);
 197                 cancel_delayed_work_sync(&conn->tx_work);
 198                 lock_sock(sk);
 199                 if (sk->sk_state == SMC_ACTIVE) {
 200                         /* send close request */
 201                         rc = smc_close_final(conn);
 202                         if (rc)
 203                                 break;
 204                         sk->sk_state = SMC_PEERCLOSEWAIT1;
 205                 } else {
 206                         /* peer event has changed the state */
 207                         goto again;
 208                 }
 209                 break;
 210         case SMC_APPFINCLOSEWAIT:
 211                 /* socket already shutdown wr or both (active close) */
 212                 if (txflags->peer_done_writing &&
 213                     !smc_close_sent_any_close(conn)) {
 214                         /* just shutdown wr done, send close request */
 215                         rc = smc_close_final(conn);
 216                         if (rc)
 217                                 break;
 218                 }
 219                 sk->sk_state = SMC_CLOSED;
 220                 break;
 221         case SMC_APPCLOSEWAIT1:
 222         case SMC_APPCLOSEWAIT2:
 223                 if (!smc_cdc_rxed_any_close(conn))
 224                         smc_close_stream_wait(smc, timeout);
 225                 release_sock(sk);
 226                 cancel_delayed_work_sync(&conn->tx_work);
 227                 lock_sock(sk);
 228                 if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
 229                     sk->sk_state != SMC_APPCLOSEWAIT2)
 230                         goto again;
 231                 /* confirm close from peer */
 232                 rc = smc_close_final(conn);
 233                 if (rc)
 234                         break;
 235                 if (smc_cdc_rxed_any_close(conn)) {
 236                         /* peer has closed the socket already */
 237                         sk->sk_state = SMC_CLOSED;
 238                         sock_put(sk); /* postponed passive closing */
 239                 } else {
 240                         /* peer has just issued a shutdown write */
 241                         sk->sk_state = SMC_PEERFINCLOSEWAIT;
 242                 }
 243                 break;
 244         case SMC_PEERCLOSEWAIT1:
 245         case SMC_PEERCLOSEWAIT2:
 246                 if (txflags->peer_done_writing &&
 247                     !smc_close_sent_any_close(conn)) {
 248                         /* just shutdown wr done, send close request */
 249                         rc = smc_close_final(conn);
 250                         if (rc)
 251                                 break;
 252                 }
 253                 /* peer sending PeerConnectionClosed will cause transition */
 254                 break;
 255         case SMC_PEERFINCLOSEWAIT:
 256                 /* peer sending PeerConnectionClosed will cause transition */
 257                 break;
 258         case SMC_PROCESSABORT:
 259                 smc_close_abort(conn);
 260                 sk->sk_state = SMC_CLOSED;
 261                 break;
 262         case SMC_PEERABORTWAIT:
 263         case SMC_CLOSED:
 264                 /* nothing to do, add tracing in future patch */
 265                 break;
 266         }
 267
 268         if (old_state != sk->sk_state)
 269                 sk->sk_state_change(sk);
 270         return rc;
 271 }
 272
 273 static void smc_close_passive_abort_received(struct smc_sock *smc)
 274 {
 275         struct smc_cdc_conn_state_flags *txflags =
 276                 &smc->conn.local_tx_ctrl.conn_state_flags;
 277         struct sock *sk = &smc->sk;
 278
 279         switch (sk->sk_state) {
 280         case SMC_INIT:
 281         case SMC_ACTIVE:
 282         case SMC_APPCLOSEWAIT1:
 283                 sk->sk_state = SMC_PROCESSABORT;
 284                 sock_put(sk); /* passive closing */
 285                 break;
 286         case SMC_APPFINCLOSEWAIT:
 287                 sk->sk_state = SMC_PROCESSABORT;
 288                 break;
 289         case SMC_PEERCLOSEWAIT1:
 290         case SMC_PEERCLOSEWAIT2:
 291                 if (txflags->peer_done_writing &&
 292                     !smc_close_sent_any_close(&smc->conn))
 293                         /* just shutdown, but not yet closed locally */
 294                         sk->sk_state = SMC_PROCESSABORT;
 295                 else
 296                         sk->sk_state = SMC_CLOSED;
 297                 sock_put(sk); /* passive closing */
 298                 break;
 299         case SMC_APPCLOSEWAIT2:
 300         case SMC_PEERFINCLOSEWAIT:
 301                 sk->sk_state = SMC_CLOSED;
 302                 sock_put(sk); /* passive closing */
 303                 break;
 304         case SMC_PEERABORTWAIT:
 305                 sk->sk_state = SMC_CLOSED;
 306                 break;
 307         case SMC_PROCESSABORT:
 308         /* nothing to do, add tracing in future patch */
 309                 break;
 310         }
 311 }
 312
 313 /* Either some kind of closing has been received: peer_conn_closed,
 314  * peer_conn_abort, or peer_done_writing
 315  * or the link group of the connection terminates abnormally.
 316  */
 317 static void smc_close_passive_work(struct work_struct *work)
 318 {
 319         struct smc_connection *conn = container_of(work,
 320                                                    struct smc_connection,
 321                                                    close_work);
 322         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 323         struct smc_cdc_conn_state_flags *rxflags;
 324         struct sock *sk = &smc->sk;
 325         int old_state;
 326
 327         lock_sock(sk);
 328         old_state = sk->sk_state;
 329
 330         if (!conn->alert_token_local) {
 331                 /* abnormal termination */
 332                 smc_close_active_abort(smc);
 333                 goto wakeup;
 334         }
 335
 336         rxflags = &conn->local_rx_ctrl.conn_state_flags;
 337         if (rxflags->peer_conn_abort) {
 338                 /* peer has not received all data */
 339                 smc_close_passive_abort_received(smc);
 340                 release_sock(&smc->sk);
 341                 cancel_delayed_work_sync(&conn->tx_work);
 342                 lock_sock(&smc->sk);
 343                 goto wakeup;
 344         }
 345
 346         switch (sk->sk_state) {
 347         case SMC_INIT:
 348                 sk->sk_state = SMC_APPCLOSEWAIT1;
 349                 break;
 350         case SMC_ACTIVE:
 351                 sk->sk_state = SMC_APPCLOSEWAIT1;
 352                 /* postpone sock_put() for passive closing to cover
 353                  * received SEND_SHUTDOWN as well
 354                  */
 355                 break;
 356         case SMC_PEERCLOSEWAIT1:
 357                 if (rxflags->peer_done_writing)
 358                         sk->sk_state = SMC_PEERCLOSEWAIT2;
 359                 /* fall through */
 360                 /* to check for closing */
 361         case SMC_PEERCLOSEWAIT2:
 362                 if (!smc_cdc_rxed_any_close(conn))
 363                         break;
 364                 if (sock_flag(sk, SOCK_DEAD) &&
 365                     smc_close_sent_any_close(conn)) {
 366                         /* smc_release has already been called locally */
 367                         sk->sk_state = SMC_CLOSED;
 368                 } else {
 369                         /* just shutdown, but not yet closed locally */
 370                         sk->sk_state = SMC_APPFINCLOSEWAIT;
 371                 }
 372                 sock_put(sk); /* passive closing */
 373                 break;
 374         case SMC_PEERFINCLOSEWAIT:
 375                 if (smc_cdc_rxed_any_close(conn)) {
 376                         sk->sk_state = SMC_CLOSED;
 377                         sock_put(sk); /* passive closing */
 378                 }
 379                 break;
 380         case SMC_APPCLOSEWAIT1:
 381         case SMC_APPCLOSEWAIT2:
 382                 /* postpone sock_put() for passive closing to cover
 383                  * received SEND_SHUTDOWN as well
 384                  */
 385                 break;
 386         case SMC_APPFINCLOSEWAIT:
 387         case SMC_PEERABORTWAIT:
 388         case SMC_PROCESSABORT:
 389         case SMC_CLOSED:
 390                 /* nothing to do, add tracing in future patch */
 391                 break;
 392         }
 393
 394 wakeup:
 395         sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
 396         sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
 397
 398         if (old_state != sk->sk_state) {
 399                 sk->sk_state_change(sk);
 400                 if ((sk->sk_state == SMC_CLOSED) &&
 401                     (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
 402                         smc_conn_free(conn);
 403                         if (smc->clcsock) {
 404                                 sock_release(smc->clcsock);
 405                                 smc->clcsock = NULL;
 406                         }
 407                 }
 408         }
 409         release_sock(sk);
 410         sock_put(sk); /* sock_hold done by schedulers of close_work */
 411 }
 412
 413 int smc_close_shutdown_write(struct smc_sock *smc)
 414 {
 415         struct smc_connection *conn = &smc->conn;
 416         struct sock *sk = &smc->sk;
 417         int old_state;
 418         long timeout;
 419         int rc = 0;
 420
 421         timeout = current->flags & PF_EXITING ?
 422                   0 : sock_flag(sk, SOCK_LINGER) ?
 423                       sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
 424
 425         old_state = sk->sk_state;
 426 again:
 427         switch (sk->sk_state) {
 428         case SMC_ACTIVE:
 429                 smc_close_stream_wait(smc, timeout);
 430                 release_sock(sk);
 431                 cancel_delayed_work_sync(&conn->tx_work);
 432                 lock_sock(sk);
 433                 if (sk->sk_state != SMC_ACTIVE)
 434                         goto again;
 435                 /* send close wr request */
 436                 rc = smc_close_wr(conn);
 437                 if (rc)
 438                         break;
 439                 sk->sk_state = SMC_PEERCLOSEWAIT1;
 440                 break;
 441         case SMC_APPCLOSEWAIT1:
 442                 /* passive close */
 443                 if (!smc_cdc_rxed_any_close(conn))
 444                         smc_close_stream_wait(smc, timeout);
 445                 release_sock(sk);
 446                 cancel_delayed_work_sync(&conn->tx_work);
 447                 lock_sock(sk);
 448                 if (sk->sk_state != SMC_APPCLOSEWAIT1)
 449                         goto again;
 450                 /* confirm close from peer */
 451                 rc = smc_close_wr(conn);
 452                 if (rc)
 453                         break;
 454                 sk->sk_state = SMC_APPCLOSEWAIT2;
 455                 break;
 456         case SMC_APPCLOSEWAIT2:
 457         case SMC_PEERFINCLOSEWAIT:
 458         case SMC_PEERCLOSEWAIT1:
 459         case SMC_PEERCLOSEWAIT2:
 460         case SMC_APPFINCLOSEWAIT:
 461         case SMC_PROCESSABORT:
 462         case SMC_PEERABORTWAIT:
 463                 /* nothing to do, add tracing in future patch */
 464                 break;
 465         }
 466
 467         if (old_state != sk->sk_state)
 468                 sk->sk_state_change(sk);
 469         return rc;
 470 }
 471
 472 /* Initialize close properties on connection establishment. */
 473 void smc_close_init(struct smc_sock *smc)
 474 {
 475         INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
 476 }