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 <[email protected]>
   9  */
  10
  11 #include <linux/workqueue.h>
  12 #include <net/sock.h>
  13
  14 #include "smc.h"
  15 #include "smc_tx.h"
  16 #include "smc_cdc.h"
  17 #include "smc_close.h"
  18
  19 #define SMC_CLOSE_WAIT_TX_PENDS_TIME            (5 * HZ)
  20
  21 static void smc_close_cleanup_listen(struct sock *parent)
  22 {
  23         struct sock *sk;
  24
  25         /* Close non-accepted connections */
  26         while ((sk = smc_accept_dequeue(parent, NULL)))
  27                 smc_close_non_accepted(sk);
  28 }
  29
  30 static void smc_close_wait_tx_pends(struct smc_sock *smc)
  31 {
  32         DEFINE_WAIT_FUNC(wait, woken_wake_function);
  33         struct sock *sk = &smc->sk;
  34         signed long timeout;
  35
  36         timeout = SMC_CLOSE_WAIT_TX_PENDS_TIME;
  37         add_wait_queue(sk_sleep(sk), &wait);
  38         while (!signal_pending(current) && timeout) {
  39                 int rc;
  40
  41                 rc = sk_wait_event(sk, &timeout,
  42                                    !smc_cdc_tx_has_pending(&smc->conn),
  43                                    &wait);
  44                 if (rc)
  45                         break;
  46         }
  47         remove_wait_queue(sk_sleep(sk), &wait);
  48 }
  49
  50 /* wait for sndbuf data being transmitted */
  51 static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
  52 {
  53         DEFINE_WAIT_FUNC(wait, woken_wake_function);
  54         struct sock *sk = &smc->sk;
  55
  56         if (!timeout)
  57                 return;
  58
  59         if (!smc_tx_prepared_sends(&smc->conn))
  60                 return;
  61
  62         smc->wait_close_tx_prepared = 1;
  63         add_wait_queue(sk_sleep(sk), &wait);
  64         while (!signal_pending(current) && timeout) {
  65                 int rc;
  66
  67                 rc = sk_wait_event(sk, &timeout,
  68                                    !smc_tx_prepared_sends(&smc->conn) ||
  69                                    (sk->sk_err == ECONNABORTED) ||
  70                                    (sk->sk_err == ECONNRESET),
  71                                    &wait);
  72                 if (rc)
  73                         break;
  74         }
  75         remove_wait_queue(sk_sleep(sk), &wait);
  76         smc->wait_close_tx_prepared = 0;
  77 }
  78
  79 void smc_close_wake_tx_prepared(struct smc_sock *smc)
  80 {
  81         if (smc->wait_close_tx_prepared)
  82                 /* wake up socket closing */
  83                 smc->sk.sk_state_change(&smc->sk);
  84 }
  85
  86 static int smc_close_wr(struct smc_connection *conn)
  87 {
  88         conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;
  89
  90         return smc_cdc_get_slot_and_msg_send(conn);
  91 }
  92
  93 static int smc_close_final(struct smc_connection *conn)
  94 {
  95         if (atomic_read(&conn->bytes_to_rcv))
  96                 conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
  97         else
  98                 conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
  99
 100         return smc_cdc_get_slot_and_msg_send(conn);
 101 }
 102
 103 static int smc_close_abort(struct smc_connection *conn)
 104 {
 105         conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 106
 107         return smc_cdc_get_slot_and_msg_send(conn);
 108 }
 109
 110 /* terminate smc socket abnormally - active abort
 111  * RDMA communication no longer possible
 112  */
 113 void smc_close_active_abort(struct smc_sock *smc)
 114 {
 115         struct smc_cdc_conn_state_flags *txflags =
 116                 &smc->conn.local_tx_ctrl.conn_state_flags;
 117
 118         bh_lock_sock(&smc->sk);
 119         smc->sk.sk_err = ECONNABORTED;
 120         if (smc->clcsock && smc->clcsock->sk) {
 121                 smc->clcsock->sk->sk_err = ECONNABORTED;
 122                 smc->clcsock->sk->sk_state_change(smc->clcsock->sk);
 123         }
 124         switch (smc->sk.sk_state) {
 125         case SMC_INIT:
 126                 smc->sk.sk_state = SMC_PEERABORTWAIT;
 127                 break;
 128         case SMC_APPCLOSEWAIT1:
 129         case SMC_APPCLOSEWAIT2:
 130                 txflags->peer_conn_abort = 1;
 131                 sock_release(smc->clcsock);
 132                 if (!smc_cdc_rxed_any_close(&smc->conn))
 133                         smc->sk.sk_state = SMC_PEERABORTWAIT;
 134                 else
 135                         smc->sk.sk_state = SMC_CLOSED;
 136                 break;
 137         case SMC_PEERCLOSEWAIT1:
 138         case SMC_PEERCLOSEWAIT2:
 139                 if (!txflags->peer_conn_closed) {
 140                         smc->sk.sk_state = SMC_PEERABORTWAIT;
 141                         txflags->peer_conn_abort = 1;
 142                         sock_release(smc->clcsock);
 143                 } else {
 144                         smc->sk.sk_state = SMC_CLOSED;
 145                 }
 146                 break;
 147         case SMC_PROCESSABORT:
 148         case SMC_APPFINCLOSEWAIT:
 149                 if (!txflags->peer_conn_closed) {
 150                         txflags->peer_conn_abort = 1;
 151                         sock_release(smc->clcsock);
 152                 }
 153                 smc->sk.sk_state = SMC_CLOSED;
 154                 break;
 155         case SMC_PEERFINCLOSEWAIT:
 156         case SMC_PEERABORTWAIT:
 157         case SMC_CLOSED:
 158                 break;
 159         }
 160
 161         sock_set_flag(&smc->sk, SOCK_DEAD);
 162         bh_unlock_sock(&smc->sk);
 163         smc->sk.sk_state_change(&smc->sk);
 164 }
 165
 166 int smc_close_active(struct smc_sock *smc)
 167 {
 168         struct smc_cdc_conn_state_flags *txflags =
 169                 &smc->conn.local_tx_ctrl.conn_state_flags;
 170         long timeout = SMC_MAX_STREAM_WAIT_TIMEOUT;
 171         struct smc_connection *conn = &smc->conn;
 172         struct sock *sk = &smc->sk;
 173         int old_state;
 174         int rc = 0;
 175
 176         if (sock_flag(sk, SOCK_LINGER) &&
 177             !(current->flags & PF_EXITING))
 178                 timeout = sk->sk_lingertime;
 179
 180 again:
 181         old_state = sk->sk_state;
 182         switch (old_state) {
 183         case SMC_INIT:
 184                 sk->sk_state = SMC_CLOSED;
 185                 if (smc->smc_listen_work.func)
 186                         flush_work(&smc->smc_listen_work);
 187                 sock_put(sk);
 188                 break;
 189         case SMC_LISTEN:
 190                 sk->sk_state = SMC_CLOSED;
 191                 sk->sk_state_change(sk); /* wake up accept */
 192                 if (smc->clcsock && smc->clcsock->sk) {
 193                         rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
 194                         /* wake up kernel_accept of smc_tcp_listen_worker */
 195                         smc->clcsock->sk->sk_data_ready(smc->clcsock->sk);
 196                 }
 197                 release_sock(sk);
 198                 smc_close_cleanup_listen(sk);
 199                 flush_work(&smc->tcp_listen_work);
 200                 lock_sock(sk);
 201                 break;
 202         case SMC_ACTIVE:
 203                 smc_close_stream_wait(smc, timeout);
 204                 release_sock(sk);
 205                 cancel_work_sync(&conn->tx_work);
 206                 lock_sock(sk);
 207                 if (sk->sk_state == SMC_ACTIVE) {
 208                         /* send close request */
 209                         rc = smc_close_final(conn);
 210                         sk->sk_state = SMC_PEERCLOSEWAIT1;
 211                 } else {
 212                         /* peer event has changed the state */
 213                         goto again;
 214                 }
 215                 break;
 216         case SMC_APPFINCLOSEWAIT:
 217                 /* socket already shutdown wr or both (active close) */
 218                 if (txflags->peer_done_writing &&
 219                     !txflags->peer_conn_closed) {
 220                         /* just shutdown wr done, send close request */
 221                         rc = smc_close_final(conn);
 222                 }
 223                 sk->sk_state = SMC_CLOSED;
 224                 smc_close_wait_tx_pends(smc);
 225                 break;
 226         case SMC_APPCLOSEWAIT1:
 227         case SMC_APPCLOSEWAIT2:
 228                 if (!smc_cdc_rxed_any_close(conn))
 229                         smc_close_stream_wait(smc, timeout);
 230                 release_sock(sk);
 231                 cancel_work_sync(&conn->tx_work);
 232                 lock_sock(sk);
 233                 if (sk->sk_err != ECONNABORTED) {
 234                         /* confirm close from peer */
 235                         rc = smc_close_final(conn);
 236                         if (rc)
 237                                 break;
 238                 }
 239                 if (smc_cdc_rxed_any_close(conn))
 240                         /* peer has closed the socket already */
 241                         sk->sk_state = SMC_CLOSED;
 242                 else
 243                         /* peer has just issued a shutdown write */
 244                         sk->sk_state = SMC_PEERFINCLOSEWAIT;
 245                 smc_close_wait_tx_pends(smc);
 246                 break;
 247         case SMC_PEERCLOSEWAIT1:
 248         case SMC_PEERCLOSEWAIT2:
 249         case SMC_PEERFINCLOSEWAIT:
 250                 /* peer sending PeerConnectionClosed will cause transition */
 251                 break;
 252         case SMC_PROCESSABORT:
 253                 cancel_work_sync(&conn->tx_work);
 254                 smc_close_abort(conn);
 255                 sk->sk_state = SMC_CLOSED;
 256                 smc_close_wait_tx_pends(smc);
 257                 break;
 258         case SMC_PEERABORTWAIT:
 259         case SMC_CLOSED:
 260                 /* nothing to do, add tracing in future patch */
 261                 break;
 262         }
 263
 264         if (old_state != sk->sk_state)
 265                 sk->sk_state_change(&smc->sk);
 266         return rc;
 267 }
 268
 269 static void smc_close_passive_abort_received(struct smc_sock *smc)
 270 {
 271         struct smc_cdc_conn_state_flags *txflags =
 272                 &smc->conn.local_tx_ctrl.conn_state_flags;
 273         struct sock *sk = &smc->sk;
 274
 275         switch (sk->sk_state) {
 276         case SMC_ACTIVE:
 277         case SMC_APPFINCLOSEWAIT:
 278         case SMC_APPCLOSEWAIT1:
 279         case SMC_APPCLOSEWAIT2:
 280                 smc_close_abort(&smc->conn);
 281                 sk->sk_state = SMC_PROCESSABORT;
 282                 break;
 283         case SMC_PEERCLOSEWAIT1:
 284         case SMC_PEERCLOSEWAIT2:
 285                 if (txflags->peer_done_writing &&
 286                     !txflags->peer_conn_closed) {
 287                         /* just shutdown, but not yet closed locally */
 288                         smc_close_abort(&smc->conn);
 289                         sk->sk_state = SMC_PROCESSABORT;
 290                 } else {
 291                         sk->sk_state = SMC_CLOSED;
 292                 }
 293                 break;
 294         case SMC_PEERFINCLOSEWAIT:
 295         case SMC_PEERABORTWAIT:
 296                 sk->sk_state = SMC_CLOSED;
 297                 break;
 298         case SMC_INIT:
 299         case SMC_PROCESSABORT:
 300         /* nothing to do, add tracing in future patch */
 301                 break;
 302         }
 303 }
 304
 305 /* Some kind of closing has been received: peer_conn_closed, peer_conn_abort,
 306  * or peer_done_writing.
 307  * Called under tasklet context.
 308  */
 309 void smc_close_passive_received(struct smc_sock *smc)
 310 {
 311         struct smc_cdc_conn_state_flags *rxflags =
 312                 &smc->conn.local_rx_ctrl.conn_state_flags;
 313         struct sock *sk = &smc->sk;
 314         int old_state;
 315
 316         sk->sk_shutdown |= RCV_SHUTDOWN;
 317         if (smc->clcsock && smc->clcsock->sk)
 318                 smc->clcsock->sk->sk_shutdown |= RCV_SHUTDOWN;
 319         sock_set_flag(&smc->sk, SOCK_DONE);
 320
 321         old_state = sk->sk_state;
 322
 323         if (rxflags->peer_conn_abort) {
 324                 smc_close_passive_abort_received(smc);
 325                 goto wakeup;
 326         }
 327
 328         switch (sk->sk_state) {
 329         case SMC_INIT:
 330                 if (atomic_read(&smc->conn.bytes_to_rcv) ||
 331                     (rxflags->peer_done_writing &&
 332                      !rxflags->peer_conn_closed))
 333                         sk->sk_state = SMC_APPCLOSEWAIT1;
 334                 else
 335                         sk->sk_state = SMC_CLOSED;
 336                 break;
 337         case SMC_ACTIVE:
 338                 sk->sk_state = SMC_APPCLOSEWAIT1;
 339                 break;
 340         case SMC_PEERCLOSEWAIT1:
 341                 if (rxflags->peer_done_writing)
 342                         sk->sk_state = SMC_PEERCLOSEWAIT2;
 343                 /* fall through to check for closing */
 344         case SMC_PEERCLOSEWAIT2:
 345         case SMC_PEERFINCLOSEWAIT:
 346                 if (!smc_cdc_rxed_any_close(&smc->conn))
 347                         break;
 348                 if (sock_flag(sk, SOCK_DEAD) &&
 349                     (sk->sk_shutdown == SHUTDOWN_MASK)) {
 350                         /* smc_release has already been called locally */
 351                         sk->sk_state = SMC_CLOSED;
 352                 } else {
 353                         /* just shutdown, but not yet closed locally */
 354                         sk->sk_state = SMC_APPFINCLOSEWAIT;
 355                 }
 356                 break;
 357         case SMC_APPCLOSEWAIT1:
 358         case SMC_APPCLOSEWAIT2:
 359         case SMC_APPFINCLOSEWAIT:
 360         case SMC_PEERABORTWAIT:
 361         case SMC_PROCESSABORT:
 362         case SMC_CLOSED:
 363                 /* nothing to do, add tracing in future patch */
 364                 break;
 365         }
 366
 367 wakeup:
 368         if (old_state != sk->sk_state)
 369                 sk->sk_state_change(sk);
 370         sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
 371         sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
 372
 373         if ((sk->sk_state == SMC_CLOSED) &&
 374             (sock_flag(sk, SOCK_DEAD) || (old_state == SMC_INIT))) {
 375                 smc_conn_free(&smc->conn);
 376                 schedule_delayed_work(&smc->sock_put_work,
 377                                       SMC_CLOSE_SOCK_PUT_DELAY);
 378         }
 379 }
 380
 381 void smc_close_sock_put_work(struct work_struct *work)
 382 {
 383         struct smc_sock *smc = container_of(to_delayed_work(work),
 384                                             struct smc_sock,
 385                                             sock_put_work);
 386
 387         smc->sk.sk_prot->unhash(&smc->sk);
 388         sock_put(&smc->sk);
 389 }
 390
 391 int smc_close_shutdown_write(struct smc_sock *smc)
 392 {
 393         struct smc_connection *conn = &smc->conn;
 394         long timeout = SMC_MAX_STREAM_WAIT_TIMEOUT;
 395         struct sock *sk = &smc->sk;
 396         int old_state;
 397         int rc = 0;
 398
 399         if (sock_flag(sk, SOCK_LINGER))
 400                 timeout = sk->sk_lingertime;
 401
 402 again:
 403         old_state = sk->sk_state;
 404         switch (old_state) {
 405         case SMC_ACTIVE:
 406                 smc_close_stream_wait(smc, timeout);
 407                 release_sock(sk);
 408                 cancel_work_sync(&conn->tx_work);
 409                 lock_sock(sk);
 410                 /* send close wr request */
 411                 rc = smc_close_wr(conn);
 412                 if (sk->sk_state == SMC_ACTIVE)
 413                         sk->sk_state = SMC_PEERCLOSEWAIT1;
 414                 else
 415                         goto again;
 416                 break;
 417         case SMC_APPCLOSEWAIT1:
 418                 /* passive close */
 419                 if (!smc_cdc_rxed_any_close(conn))
 420                         smc_close_stream_wait(smc, timeout);
 421                 release_sock(sk);
 422                 cancel_work_sync(&conn->tx_work);
 423                 lock_sock(sk);
 424                 /* confirm close from peer */
 425                 rc = smc_close_wr(conn);
 426                 sk->sk_state = SMC_APPCLOSEWAIT2;
 427                 break;
 428         case SMC_APPCLOSEWAIT2:
 429         case SMC_PEERFINCLOSEWAIT:
 430         case SMC_PEERCLOSEWAIT1:
 431         case SMC_PEERCLOSEWAIT2:
 432         case SMC_APPFINCLOSEWAIT:
 433         case SMC_PROCESSABORT:
 434         case SMC_PEERABORTWAIT:
 435                 /* nothing to do, add tracing in future patch */
 436                 break;
 437         }
 438
 439         if (old_state != sk->sk_state)
 440                 sk->sk_state_change(&smc->sk);
 441         return rc;
 442 }