net/smc/smc_close.c

   1 /*
   2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   3  *
   4  *  Socket Closing - normal and abnormal
   5  *
   6  *  Copyright IBM Corp. 2016
   7  *
   8  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
   9  */
  10
  11 #include <linux/workqueue.h>
  12 #include <linux/sched/signal.h>
  13
  14 #include <net/sock.h>
  15
  16 #include "smc.h"
  17 #include "smc_tx.h"
  18 #include "smc_cdc.h"
  19 #include "smc_close.h"
  20
  21 #define SMC_CLOSE_WAIT_TX_PENDS_TIME            (5 * HZ)
  22
  23 static void smc_close_cleanup_listen(struct sock *parent)
  24 {
  25         struct sock *sk;
  26
  27         /* Close non-accepted connections */
  28         while ((sk = smc_accept_dequeue(parent, NULL)))
  29                 smc_close_non_accepted(sk);
  30 }
  31
  32 static void smc_close_wait_tx_pends(struct smc_sock *smc)
  33 {
  34         DEFINE_WAIT_FUNC(wait, woken_wake_function);
  35         struct sock *sk = &smc->sk;
  36         signed long timeout;
  37
  38         timeout = SMC_CLOSE_WAIT_TX_PENDS_TIME;
  39         add_wait_queue(sk_sleep(sk), &wait);
  40         while (!signal_pending(current) && timeout) {
  41                 int rc;
  42
  43                 rc = sk_wait_event(sk, &timeout,
  44                                    !smc_cdc_tx_has_pending(&smc->conn),
  45                                    &wait);
  46                 if (rc)
  47                         break;
  48         }
  49         remove_wait_queue(sk_sleep(sk), &wait);
  50 }
  51
  52 /* wait for sndbuf data being transmitted */
  53 static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
  54 {
  55         DEFINE_WAIT_FUNC(wait, woken_wake_function);
  56         struct sock *sk = &smc->sk;
  57
  58         if (!timeout)
  59                 return;
  60
  61         if (!smc_tx_prepared_sends(&smc->conn))
  62                 return;
  63
  64         smc->wait_close_tx_prepared = 1;
  65         add_wait_queue(sk_sleep(sk), &wait);
  66         while (!signal_pending(current) && timeout) {
  67                 int rc;
  68
  69                 rc = sk_wait_event(sk, &timeout,
  70                                    !smc_tx_prepared_sends(&smc->conn) ||
  71                                    (sk->sk_err == ECONNABORTED) ||
  72                                    (sk->sk_err == ECONNRESET),
  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
 102         return smc_cdc_get_slot_and_msg_send(conn);
 103 }
 104
 105 static int smc_close_abort(struct smc_connection *conn)
 106 {
 107         conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 108
 109         return smc_cdc_get_slot_and_msg_send(conn);
 110 }
 111
 112 /* terminate smc socket abnormally - active abort
 113  * RDMA communication no longer possible
 114  */
 115 void smc_close_active_abort(struct smc_sock *smc)
 116 {
 117         struct smc_cdc_conn_state_flags *txflags =
 118                 &smc->conn.local_tx_ctrl.conn_state_flags;
 119
 120         smc->sk.sk_err = ECONNABORTED;
 121         if (smc->clcsock && smc->clcsock->sk) {
 122                 smc->clcsock->sk->sk_err = ECONNABORTED;
 123                 smc->clcsock->sk->sk_state_change(smc->clcsock->sk);
 124         }
 125         switch (smc->sk.sk_state) {
 126         case SMC_INIT:
 127         case SMC_ACTIVE:
 128                 smc->sk.sk_state = SMC_PEERABORTWAIT;
 129                 break;
 130         case SMC_APPCLOSEWAIT1:
 131         case SMC_APPCLOSEWAIT2:
 132                 txflags->peer_conn_abort = 1;
 133                 sock_release(smc->clcsock);
 134                 if (!smc_cdc_rxed_any_close(&smc->conn))
 135                         smc->sk.sk_state = SMC_PEERABORTWAIT;
 136                 else
 137                         smc->sk.sk_state = SMC_CLOSED;
 138                 break;
 139         case SMC_PEERCLOSEWAIT1:
 140         case SMC_PEERCLOSEWAIT2:
 141                 if (!txflags->peer_conn_closed) {
 142                         smc->sk.sk_state = SMC_PEERABORTWAIT;
 143                         txflags->peer_conn_abort = 1;
 144                         sock_release(smc->clcsock);
 145                 } else {
 146                         smc->sk.sk_state = SMC_CLOSED;
 147                 }
 148                 break;
 149         case SMC_PROCESSABORT:
 150         case SMC_APPFINCLOSEWAIT:
 151                 if (!txflags->peer_conn_closed) {
 152                         txflags->peer_conn_abort = 1;
 153                         sock_release(smc->clcsock);
 154                 }
 155                 smc->sk.sk_state = SMC_CLOSED;
 156                 break;
 157         case SMC_PEERFINCLOSEWAIT:
 158         case SMC_PEERABORTWAIT:
 159         case SMC_CLOSED:
 160                 break;
 161         }
 162
 163         sock_set_flag(&smc->sk, SOCK_DEAD);
 164         smc->sk.sk_state_change(&smc->sk);
 165 }
 166
 167 static inline bool smc_close_sent_any_close(struct smc_connection *conn)
 168 {
 169         return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
 170                conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
 171 }
 172
 173 int smc_close_active(struct smc_sock *smc)
 174 {
 175         struct smc_cdc_conn_state_flags *txflags =
 176                 &smc->conn.local_tx_ctrl.conn_state_flags;
 177         long timeout = SMC_MAX_STREAM_WAIT_TIMEOUT;
 178         struct smc_connection *conn = &smc->conn;
 179         struct sock *sk = &smc->sk;
 180         int old_state;
 181         int rc = 0;
 182
 183         if (sock_flag(sk, SOCK_LINGER) &&
 184             !(current->flags & PF_EXITING))
 185                 timeout = sk->sk_lingertime;
 186
 187 again:
 188         old_state = sk->sk_state;
 189         switch (old_state) {
 190         case SMC_INIT:
 191                 sk->sk_state = SMC_CLOSED;
 192                 if (smc->smc_listen_work.func)
 193                         cancel_work_sync(&smc->smc_listen_work);
 194                 break;
 195         case SMC_LISTEN:
 196                 sk->sk_state = SMC_CLOSED;
 197                 sk->sk_state_change(sk); /* wake up accept */
 198                 if (smc->clcsock && smc->clcsock->sk) {
 199                         rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
 200                         /* wake up kernel_accept of smc_tcp_listen_worker */
 201                         smc->clcsock->sk->sk_data_ready(smc->clcsock->sk);
 202                 }
 203                 release_sock(sk);
 204                 smc_close_cleanup_listen(sk);
 205                 cancel_work_sync(&smc->smc_listen_work);
 206                 lock_sock(sk);
 207                 break;
 208         case SMC_ACTIVE:
 209                 smc_close_stream_wait(smc, timeout);
 210                 release_sock(sk);
 211                 cancel_work_sync(&conn->tx_work);
 212                 lock_sock(sk);
 213                 if (sk->sk_state == SMC_ACTIVE) {
 214                         /* send close request */
 215                         rc = smc_close_final(conn);
 216                         sk->sk_state = SMC_PEERCLOSEWAIT1;
 217                 } else {
 218                         /* peer event has changed the state */
 219                         goto again;
 220                 }
 221                 break;
 222         case SMC_APPFINCLOSEWAIT:
 223                 /* socket already shutdown wr or both (active close) */
 224                 if (txflags->peer_done_writing &&
 225                     !smc_close_sent_any_close(conn)) {
 226                         /* just shutdown wr done, send close request */
 227                         rc = smc_close_final(conn);
 228                 }
 229                 sk->sk_state = SMC_CLOSED;
 230                 smc_close_wait_tx_pends(smc);
 231                 break;
 232         case SMC_APPCLOSEWAIT1:
 233         case SMC_APPCLOSEWAIT2:
 234                 if (!smc_cdc_rxed_any_close(conn))
 235                         smc_close_stream_wait(smc, timeout);
 236                 release_sock(sk);
 237                 cancel_work_sync(&conn->tx_work);
 238                 lock_sock(sk);
 239                 if (sk->sk_err != ECONNABORTED) {
 240                         /* confirm close from peer */
 241                         rc = smc_close_final(conn);
 242                         if (rc)
 243                                 break;
 244                 }
 245                 if (smc_cdc_rxed_any_close(conn))
 246                         /* peer has closed the socket already */
 247                         sk->sk_state = SMC_CLOSED;
 248                 else
 249                         /* peer has just issued a shutdown write */
 250                         sk->sk_state = SMC_PEERFINCLOSEWAIT;
 251                 smc_close_wait_tx_pends(smc);
 252                 break;
 253         case SMC_PEERCLOSEWAIT1:
 254         case SMC_PEERCLOSEWAIT2:
 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                 /* peer sending PeerConnectionClosed will cause transition */
 261                 break;
 262         case SMC_PEERFINCLOSEWAIT:
 263                 /* peer sending PeerConnectionClosed will cause transition */
 264                 break;
 265         case SMC_PROCESSABORT:
 266                 cancel_work_sync(&conn->tx_work);
 267                 smc_close_abort(conn);
 268                 sk->sk_state = SMC_CLOSED;
 269                 smc_close_wait_tx_pends(smc);
 270                 break;
 271         case SMC_PEERABORTWAIT:
 272         case SMC_CLOSED:
 273                 /* nothing to do, add tracing in future patch */
 274                 break;
 275         }
 276
 277         if (old_state != sk->sk_state)
 278                 sk->sk_state_change(&smc->sk);
 279         return rc;
 280 }
 281
 282 static void smc_close_passive_abort_received(struct smc_sock *smc)
 283 {
 284         struct smc_cdc_conn_state_flags *txflags =
 285                 &smc->conn.local_tx_ctrl.conn_state_flags;
 286         struct sock *sk = &smc->sk;
 287
 288         switch (sk->sk_state) {
 289         case SMC_ACTIVE:
 290         case SMC_APPFINCLOSEWAIT:
 291         case SMC_APPCLOSEWAIT1:
 292         case SMC_APPCLOSEWAIT2:
 293                 smc_close_abort(&smc->conn);
 294                 sk->sk_state = SMC_PROCESSABORT;
 295                 break;
 296         case SMC_PEERCLOSEWAIT1:
 297         case SMC_PEERCLOSEWAIT2:
 298                 if (txflags->peer_done_writing &&
 299                     !smc_close_sent_any_close(&smc->conn)) {
 300                         /* just shutdown, but not yet closed locally */
 301                         smc_close_abort(&smc->conn);
 302                         sk->sk_state = SMC_PROCESSABORT;
 303                 } else {
 304                         sk->sk_state = SMC_CLOSED;
 305                 }
 306                 break;
 307         case SMC_PEERFINCLOSEWAIT:
 308         case SMC_PEERABORTWAIT:
 309                 sk->sk_state = SMC_CLOSED;
 310                 break;
 311         case SMC_INIT:
 312         case SMC_PROCESSABORT:
 313         /* nothing to do, add tracing in future patch */
 314                 break;
 315         }
 316 }
 317
 318 /* Some kind of closing has been received: peer_conn_closed, peer_conn_abort,
 319  * or peer_done_writing.
 320  */
 321 static void smc_close_passive_work(struct work_struct *work)
 322 {
 323         struct smc_connection *conn = container_of(work,
 324                                                    struct smc_connection,
 325                                                    close_work);
 326         struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
 327         struct smc_cdc_conn_state_flags *rxflags;
 328         struct sock *sk = &smc->sk;
 329         int old_state;
 330
 331         lock_sock(&smc->sk);
 332         old_state = sk->sk_state;
 333
 334         if (!conn->alert_token_local) {
 335                 /* abnormal termination */
 336                 smc_close_active_abort(smc);
 337                 goto wakeup;
 338         }
 339
 340         rxflags = &smc->conn.local_rx_ctrl.conn_state_flags;
 341         if (rxflags->peer_conn_abort) {
 342                 smc_close_passive_abort_received(smc);
 343                 goto wakeup;
 344         }
 345
 346         switch (sk->sk_state) {
 347         case SMC_INIT:
 348                 if (atomic_read(&smc->conn.bytes_to_rcv) ||
 349                     (rxflags->peer_done_writing &&
 350                      !smc_cdc_rxed_any_close(conn)))
 351                         sk->sk_state = SMC_APPCLOSEWAIT1;
 352                 else
 353                         sk->sk_state = SMC_CLOSED;
 354                 break;
 355         case SMC_ACTIVE:
 356                 sk->sk_state = SMC_APPCLOSEWAIT1;
 357                 break;
 358         case SMC_PEERCLOSEWAIT1:
 359                 if (rxflags->peer_done_writing)
 360                         sk->sk_state = SMC_PEERCLOSEWAIT2;
 361                 /* fall through to check for closing */
 362         case SMC_PEERCLOSEWAIT2:
 363         case SMC_PEERFINCLOSEWAIT:
 364                 if (!smc_cdc_rxed_any_close(&smc->conn))
 365                         break;
 366                 if (sock_flag(sk, SOCK_DEAD) &&
 367                     smc_close_sent_any_close(conn)) {
 368                         /* smc_release has already been called locally */
 369                         sk->sk_state = SMC_CLOSED;
 370                 } else {
 371                         /* just shutdown, but not yet closed locally */
 372                         sk->sk_state = SMC_APPFINCLOSEWAIT;
 373                 }
 374                 break;
 375         case SMC_APPCLOSEWAIT1:
 376         case SMC_APPCLOSEWAIT2:
 377         case SMC_APPFINCLOSEWAIT:
 378         case SMC_PEERABORTWAIT:
 379         case SMC_PROCESSABORT:
 380         case SMC_CLOSED:
 381                 /* nothing to do, add tracing in future patch */
 382                 break;
 383         }
 384
 385 wakeup:
 386         sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
 387         sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
 388
 389         if (old_state != sk->sk_state) {
 390                 sk->sk_state_change(sk);
 391                 if ((sk->sk_state == SMC_CLOSED) &&
 392                     (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
 393                         smc_conn_free(&smc->conn);
 394                         schedule_delayed_work(&smc->sock_put_work,
 395                                               SMC_CLOSE_SOCK_PUT_DELAY);
 396                 }
 397         }
 398         release_sock(&smc->sk);
 399 }
 400
 401 void smc_close_sock_put_work(struct work_struct *work)
 402 {
 403         struct smc_sock *smc = container_of(to_delayed_work(work),
 404                                             struct smc_sock,
 405                                             sock_put_work);
 406
 407         smc->sk.sk_prot->unhash(&smc->sk);
 408         sock_put(&smc->sk);
 409 }
 410
 411 int smc_close_shutdown_write(struct smc_sock *smc)
 412 {
 413         struct smc_connection *conn = &smc->conn;
 414         long timeout = SMC_MAX_STREAM_WAIT_TIMEOUT;
 415         struct sock *sk = &smc->sk;
 416         int old_state;
 417         int rc = 0;
 418
 419         if (sock_flag(sk, SOCK_LINGER))
 420                 timeout = sk->sk_lingertime;
 421
 422 again:
 423         old_state = sk->sk_state;
 424         switch (old_state) {
 425         case SMC_ACTIVE:
 426                 smc_close_stream_wait(smc, timeout);
 427                 release_sock(sk);
 428                 cancel_work_sync(&conn->tx_work);
 429                 lock_sock(sk);
 430                 /* send close wr request */
 431                 rc = smc_close_wr(conn);
 432                 if (sk->sk_state == SMC_ACTIVE)
 433                         sk->sk_state = SMC_PEERCLOSEWAIT1;
 434                 else
 435                         goto again;
 436                 break;
 437         case SMC_APPCLOSEWAIT1:
 438                 /* passive close */
 439                 if (!smc_cdc_rxed_any_close(conn))
 440                         smc_close_stream_wait(smc, timeout);
 441                 release_sock(sk);
 442                 cancel_work_sync(&conn->tx_work);
 443                 lock_sock(sk);
 444                 /* confirm close from peer */
 445                 rc = smc_close_wr(conn);
 446                 sk->sk_state = SMC_APPCLOSEWAIT2;
 447                 break;
 448         case SMC_APPCLOSEWAIT2:
 449         case SMC_PEERFINCLOSEWAIT:
 450         case SMC_PEERCLOSEWAIT1:
 451         case SMC_PEERCLOSEWAIT2:
 452         case SMC_APPFINCLOSEWAIT:
 453         case SMC_PROCESSABORT:
 454         case SMC_PEERABORTWAIT:
 455                 /* nothing to do, add tracing in future patch */
 456                 break;
 457         }
 458
 459         if (old_state != sk->sk_state)
 460                 sk->sk_state_change(&smc->sk);
 461         return rc;
 462 }
 463
 464 /* Initialize close properties on connection establishment. */
 465 void smc_close_init(struct smc_sock *smc)
 466 {
 467         INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
 468 }