net/rxrpc/ar-call.c

   1 /* RxRPC individual remote procedure call handling
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/circ_buf.h>
  14 #include <net/sock.h>
  15 #include <net/af_rxrpc.h>
  16 #include "ar-internal.h"
  17
  18 struct kmem_cache *rxrpc_call_jar;
  19 LIST_HEAD(rxrpc_calls);
  20 DEFINE_RWLOCK(rxrpc_call_lock);
  21 static unsigned rxrpc_call_max_lifetime = 60;
  22 static unsigned rxrpc_dead_call_timeout = 10;
  23
  24 static void rxrpc_destroy_call(struct work_struct *work);
  25 static void rxrpc_call_life_expired(unsigned long _call);
  26 static void rxrpc_dead_call_expired(unsigned long _call);
  27 static void rxrpc_ack_time_expired(unsigned long _call);
  28 static void rxrpc_resend_time_expired(unsigned long _call);
  29
  30 /*
  31  * allocate a new call
  32  */
  33 static struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
  34 {
  35         struct rxrpc_call *call;
  36
  37         call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
  38         if (!call)
  39                 return NULL;
  40
  41         call->acks_winsz = 16;
  42         call->acks_window = kmalloc(call->acks_winsz * sizeof(unsigned long),
  43                                     gfp);
  44         if (!call->acks_window) {
  45                 kmem_cache_free(rxrpc_call_jar, call);
  46                 return NULL;
  47         }
  48
  49         setup_timer(&call->lifetimer, &rxrpc_call_life_expired,
  50                     (unsigned long) call);
  51         setup_timer(&call->deadspan, &rxrpc_dead_call_expired,
  52                     (unsigned long) call);
  53         setup_timer(&call->ack_timer, &rxrpc_ack_time_expired,
  54                     (unsigned long) call);
  55         setup_timer(&call->resend_timer, &rxrpc_resend_time_expired,
  56                     (unsigned long) call);
  57         INIT_WORK(&call->destroyer, &rxrpc_destroy_call);
  58         INIT_WORK(&call->processor, &rxrpc_process_call);
  59         INIT_LIST_HEAD(&call->accept_link);
  60         skb_queue_head_init(&call->rx_queue);
  61         skb_queue_head_init(&call->rx_oos_queue);
  62         init_waitqueue_head(&call->tx_waitq);
  63         spin_lock_init(&call->lock);
  64         rwlock_init(&call->state_lock);
  65         atomic_set(&call->usage, 1);
  66         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
  67         call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
  68
  69         memset(&call->sock_node, 0xed, sizeof(call->sock_node));
  70
  71         call->rx_data_expect = 1;
  72         call->rx_data_eaten = 0;
  73         call->rx_first_oos = 0;
  74         call->ackr_win_top = call->rx_data_eaten + 1 + RXRPC_MAXACKS;
  75         call->creation_jif = jiffies;
  76         return call;
  77 }
  78
  79 /*
  80  * allocate a new client call and attempt to to get a connection slot for it
  81  */
  82 static struct rxrpc_call *rxrpc_alloc_client_call(
  83         struct rxrpc_sock *rx,
  84         struct rxrpc_transport *trans,
  85         struct rxrpc_conn_bundle *bundle,
  86         gfp_t gfp)
  87 {
  88         struct rxrpc_call *call;
  89         int ret;
  90
  91         _enter("");
  92
  93         ASSERT(rx != NULL);
  94         ASSERT(trans != NULL);
  95         ASSERT(bundle != NULL);
  96
  97         call = rxrpc_alloc_call(gfp);
  98         if (!call)
  99                 return ERR_PTR(-ENOMEM);
 100
 101         sock_hold(&rx->sk);
 102         call->socket = rx;
 103         call->rx_data_post = 1;
 104
 105         ret = rxrpc_connect_call(rx, trans, bundle, call, gfp);
 106         if (ret < 0) {
 107                 kmem_cache_free(rxrpc_call_jar, call);
 108                 return ERR_PTR(ret);
 109         }
 110
 111         spin_lock(&call->conn->trans->peer->lock);
 112         list_add(&call->error_link, &call->conn->trans->peer->error_targets);
 113         spin_unlock(&call->conn->trans->peer->lock);
 114
 115         call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
 116         add_timer(&call->lifetimer);
 117
 118         _leave(" = %p", call);
 119         return call;
 120 }
 121
 122 /*
 123  * set up a call for the given data
 124  * - called in process context with IRQs enabled
 125  */
 126 struct rxrpc_call *rxrpc_get_client_call(struct rxrpc_sock *rx,
 127                                          struct rxrpc_transport *trans,
 128                                          struct rxrpc_conn_bundle *bundle,
 129                                          unsigned long user_call_ID,
 130                                          int create,
 131                                          gfp_t gfp)
 132 {
 133         struct rxrpc_call *call, *candidate;
 134         struct rb_node *p, *parent, **pp;
 135
 136         _enter("%p,%d,%d,%lx,%d",
 137                rx, trans ? trans->debug_id : -1, bundle ? bundle->debug_id : -1,
 138                user_call_ID, create);
 139
 140         /* search the extant calls first for one that matches the specified
 141          * user ID */
 142         read_lock(&rx->call_lock);
 143
 144         p = rx->calls.rb_node;
 145         while (p) {
 146                 call = rb_entry(p, struct rxrpc_call, sock_node);
 147
 148                 if (user_call_ID < call->user_call_ID)
 149                         p = p->rb_left;
 150                 else if (user_call_ID > call->user_call_ID)
 151                         p = p->rb_right;
 152                 else
 153                         goto found_extant_call;
 154         }
 155
 156         read_unlock(&rx->call_lock);
 157
 158         if (!create || !trans)
 159                 return ERR_PTR(-EBADSLT);
 160
 161         /* not yet present - create a candidate for a new record and then
 162          * redo the search */
 163         candidate = rxrpc_alloc_client_call(rx, trans, bundle, gfp);
 164         if (IS_ERR(candidate)) {
 165                 _leave(" = %ld", PTR_ERR(candidate));
 166                 return candidate;
 167         }
 168
 169         candidate->user_call_ID = user_call_ID;
 170         __set_bit(RXRPC_CALL_HAS_USERID, &candidate->flags);
 171
 172         write_lock(&rx->call_lock);
 173
 174         pp = &rx->calls.rb_node;
 175         parent = NULL;
 176         while (*pp) {
 177                 parent = *pp;
 178                 call = rb_entry(parent, struct rxrpc_call, sock_node);
 179
 180                 if (user_call_ID < call->user_call_ID)
 181                         pp = &(*pp)->rb_left;
 182                 else if (user_call_ID > call->user_call_ID)
 183                         pp = &(*pp)->rb_right;
 184                 else
 185                         goto found_extant_second;
 186         }
 187
 188         /* second search also failed; add the new call */
 189         call = candidate;
 190         candidate = NULL;
 191         rxrpc_get_call(call);
 192
 193         rb_link_node(&call->sock_node, parent, pp);
 194         rb_insert_color(&call->sock_node, &rx->calls);
 195         write_unlock(&rx->call_lock);
 196
 197         write_lock_bh(&rxrpc_call_lock);
 198         list_add_tail(&call->link, &rxrpc_calls);
 199         write_unlock_bh(&rxrpc_call_lock);
 200
 201         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
 202
 203         _leave(" = %p [new]", call);
 204         return call;
 205
 206         /* we found the call in the list immediately */
 207 found_extant_call:
 208         rxrpc_get_call(call);
 209         read_unlock(&rx->call_lock);
 210         _leave(" = %p [extant %d]", call, atomic_read(&call->usage));
 211         return call;
 212
 213         /* we found the call on the second time through the list */
 214 found_extant_second:
 215         rxrpc_get_call(call);
 216         write_unlock(&rx->call_lock);
 217         rxrpc_put_call(candidate);
 218         _leave(" = %p [second %d]", call, atomic_read(&call->usage));
 219         return call;
 220 }
 221
 222 /*
 223  * set up an incoming call
 224  * - called in process context with IRQs enabled
 225  */
 226 struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
 227                                        struct rxrpc_connection *conn,
 228                                        struct rxrpc_header *hdr,
 229                                        gfp_t gfp)
 230 {
 231         struct rxrpc_call *call, *candidate;
 232         struct rb_node **p, *parent;
 233         __be32 call_id;
 234
 235         _enter(",%d,,%x", conn->debug_id, gfp);
 236
 237         ASSERT(rx != NULL);
 238
 239         candidate = rxrpc_alloc_call(gfp);
 240         if (!candidate)
 241                 return ERR_PTR(-EBUSY);
 242
 243         candidate->socket = rx;
 244         candidate->conn = conn;
 245         candidate->cid = hdr->cid;
 246         candidate->call_id = hdr->callNumber;
 247         candidate->channel = ntohl(hdr->cid) & RXRPC_CHANNELMASK;
 248         candidate->rx_data_post = 0;
 249         candidate->state = RXRPC_CALL_SERVER_ACCEPTING;
 250         if (conn->security_ix > 0)
 251                 candidate->state = RXRPC_CALL_SERVER_SECURING;
 252
 253         write_lock_bh(&conn->lock);
 254
 255         /* set the channel for this call */
 256         call = conn->channels[candidate->channel];
 257         _debug("channel[%u] is %p", candidate->channel, call);
 258         if (call && call->call_id == hdr->callNumber) {
 259                 /* already set; must've been a duplicate packet */
 260                 _debug("extant call [%d]", call->state);
 261                 ASSERTCMP(call->conn, ==, conn);
 262
 263                 read_lock(&call->state_lock);
 264                 switch (call->state) {
 265                 case RXRPC_CALL_LOCALLY_ABORTED:
 266                         if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events))
 267                                 schedule_work(&call->processor);
 268                 case RXRPC_CALL_REMOTELY_ABORTED:
 269                         read_unlock(&call->state_lock);
 270                         goto aborted_call;
 271                 default:
 272                         rxrpc_get_call(call);
 273                         read_unlock(&call->state_lock);
 274                         goto extant_call;
 275                 }
 276         }
 277
 278         if (call) {
 279                 /* it seems the channel is still in use from the previous call
 280                  * - ditch the old binding if its call is now complete */
 281                 _debug("CALL: %u { %s }",
 282                        call->debug_id, rxrpc_call_states[call->state]);
 283
 284                 if (call->state >= RXRPC_CALL_COMPLETE) {
 285                         conn->channels[call->channel] = NULL;
 286                 } else {
 287                         write_unlock_bh(&conn->lock);
 288                         kmem_cache_free(rxrpc_call_jar, candidate);
 289                         _leave(" = -EBUSY");
 290                         return ERR_PTR(-EBUSY);
 291                 }
 292         }
 293
 294         /* check the call number isn't duplicate */
 295         _debug("check dup");
 296         call_id = hdr->callNumber;
 297         p = &conn->calls.rb_node;
 298         parent = NULL;
 299         while (*p) {
 300                 parent = *p;
 301                 call = rb_entry(parent, struct rxrpc_call, conn_node);
 302
 303                 if (call_id < call->call_id)
 304                         p = &(*p)->rb_left;
 305                 else if (call_id > call->call_id)
 306                         p = &(*p)->rb_right;
 307                 else
 308                         goto old_call;
 309         }
 310
 311         /* make the call available */
 312         _debug("new call");
 313         call = candidate;
 314         candidate = NULL;
 315         rb_link_node(&call->conn_node, parent, p);
 316         rb_insert_color(&call->conn_node, &conn->calls);
 317         conn->channels[call->channel] = call;
 318         sock_hold(&rx->sk);
 319         atomic_inc(&conn->usage);
 320         write_unlock_bh(&conn->lock);
 321
 322         spin_lock(&conn->trans->peer->lock);
 323         list_add(&call->error_link, &conn->trans->peer->error_targets);
 324         spin_unlock(&conn->trans->peer->lock);
 325
 326         write_lock_bh(&rxrpc_call_lock);
 327         list_add_tail(&call->link, &rxrpc_calls);
 328         write_unlock_bh(&rxrpc_call_lock);
 329
 330         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
 331
 332         call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
 333         add_timer(&call->lifetimer);
 334         _leave(" = %p {%d} [new]", call, call->debug_id);
 335         return call;
 336
 337 extant_call:
 338         write_unlock_bh(&conn->lock);
 339         kmem_cache_free(rxrpc_call_jar, candidate);
 340         _leave(" = %p {%d} [extant]", call, call ? call->debug_id : -1);
 341         return call;
 342
 343 aborted_call:
 344         write_unlock_bh(&conn->lock);
 345         kmem_cache_free(rxrpc_call_jar, candidate);
 346         _leave(" = -ECONNABORTED");
 347         return ERR_PTR(-ECONNABORTED);
 348
 349 old_call:
 350         write_unlock_bh(&conn->lock);
 351         kmem_cache_free(rxrpc_call_jar, candidate);
 352         _leave(" = -ECONNRESET [old]");
 353         return ERR_PTR(-ECONNRESET);
 354 }
 355
 356 /*
 357  * find an extant server call
 358  * - called in process context with IRQs enabled
 359  */
 360 struct rxrpc_call *rxrpc_find_server_call(struct rxrpc_sock *rx,
 361                                           unsigned long user_call_ID)
 362 {
 363         struct rxrpc_call *call;
 364         struct rb_node *p;
 365
 366         _enter("%p,%lx", rx, user_call_ID);
 367
 368         /* search the extant calls for one that matches the specified user
 369          * ID */
 370         read_lock(&rx->call_lock);
 371
 372         p = rx->calls.rb_node;
 373         while (p) {
 374                 call = rb_entry(p, struct rxrpc_call, sock_node);
 375
 376                 if (user_call_ID < call->user_call_ID)
 377                         p = p->rb_left;
 378                 else if (user_call_ID > call->user_call_ID)
 379                         p = p->rb_right;
 380                 else
 381                         goto found_extant_call;
 382         }
 383
 384         read_unlock(&rx->call_lock);
 385         _leave(" = NULL");
 386         return NULL;
 387
 388         /* we found the call in the list immediately */
 389 found_extant_call:
 390         rxrpc_get_call(call);
 391         read_unlock(&rx->call_lock);
 392         _leave(" = %p [%d]", call, atomic_read(&call->usage));
 393         return call;
 394 }
 395
 396 /*
 397  * detach a call from a socket and set up for release
 398  */
 399 void rxrpc_release_call(struct rxrpc_call *call)
 400 {
 401         struct rxrpc_sock *rx = call->socket;
 402
 403         _enter("{%d,%d,%d,%d}",
 404                call->debug_id, atomic_read(&call->usage),
 405                atomic_read(&call->ackr_not_idle),
 406                call->rx_first_oos);
 407
 408         spin_lock_bh(&call->lock);
 409         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 410                 BUG();
 411         spin_unlock_bh(&call->lock);
 412
 413         /* dissociate from the socket
 414          * - the socket's ref on the call is passed to the death timer
 415          */
 416         _debug("RELEASE CALL %p (%d CONN %p)",
 417                call, call->debug_id, call->conn);
 418
 419         write_lock_bh(&rx->call_lock);
 420         if (!list_empty(&call->accept_link)) {
 421                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 422                        call, call->events, call->flags);
 423                 ASSERT(!test_bit(RXRPC_CALL_HAS_USERID, &call->flags));
 424                 list_del_init(&call->accept_link);
 425                 sk_acceptq_removed(&rx->sk);
 426         } else if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 427                 rb_erase(&call->sock_node, &rx->calls);
 428                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 429                 clear_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 430         }
 431         write_unlock_bh(&rx->call_lock);
 432
 433         if (call->conn->out_clientflag)
 434                 spin_lock(&call->conn->trans->client_lock);
 435         write_lock_bh(&call->conn->lock);
 436
 437         /* free up the channel for reuse */
 438         if (call->conn->out_clientflag) {
 439                 call->conn->avail_calls++;
 440                 if (call->conn->avail_calls == RXRPC_MAXCALLS)
 441                         list_move_tail(&call->conn->bundle_link,
 442                                        &call->conn->bundle->unused_conns);
 443                 else if (call->conn->avail_calls == 1)
 444                         list_move_tail(&call->conn->bundle_link,
 445                                        &call->conn->bundle->avail_conns);
 446         }
 447
 448         write_lock(&call->state_lock);
 449         if (call->conn->channels[call->channel] == call)
 450                 call->conn->channels[call->channel] = NULL;
 451
 452         if (call->state < RXRPC_CALL_COMPLETE &&
 453             call->state != RXRPC_CALL_CLIENT_FINAL_ACK) {
 454                 _debug("+++ ABORTING STATE %d +++\n", call->state);
 455                 call->state = RXRPC_CALL_LOCALLY_ABORTED;
 456                 call->abort_code = RX_CALL_DEAD;
 457                 set_bit(RXRPC_CALL_ABORT, &call->events);
 458                 schedule_work(&call->processor);
 459         }
 460         write_unlock(&call->state_lock);
 461         write_unlock_bh(&call->conn->lock);
 462         if (call->conn->out_clientflag)
 463                 spin_unlock(&call->conn->trans->client_lock);
 464
 465         if (!skb_queue_empty(&call->rx_queue) ||
 466             !skb_queue_empty(&call->rx_oos_queue)) {
 467                 struct rxrpc_skb_priv *sp;
 468                 struct sk_buff *skb;
 469
 470                 _debug("purge Rx queues");
 471
 472                 spin_lock_bh(&call->lock);
 473                 while ((skb = skb_dequeue(&call->rx_queue)) ||
 474                        (skb = skb_dequeue(&call->rx_oos_queue))) {
 475                         sp = rxrpc_skb(skb);
 476                         if (sp->call) {
 477                                 ASSERTCMP(sp->call, ==, call);
 478                                 rxrpc_put_call(call);
 479                                 sp->call = NULL;
 480                         }
 481                         skb->destructor = NULL;
 482                         spin_unlock_bh(&call->lock);
 483
 484                         _debug("- zap %s %%%u #%u",
 485                                rxrpc_pkts[sp->hdr.type],
 486                                ntohl(sp->hdr.serial),
 487                                ntohl(sp->hdr.seq));
 488                         rxrpc_free_skb(skb);
 489                         spin_lock_bh(&call->lock);
 490                 }
 491                 spin_unlock_bh(&call->lock);
 492
 493                 ASSERTCMP(call->state, !=, RXRPC_CALL_COMPLETE);
 494         }
 495
 496         del_timer_sync(&call->resend_timer);
 497         del_timer_sync(&call->ack_timer);
 498         del_timer_sync(&call->lifetimer);
 499         call->deadspan.expires = jiffies + rxrpc_dead_call_timeout * HZ;
 500         add_timer(&call->deadspan);
 501
 502         _leave("");
 503 }
 504
 505 /*
 506  * handle a dead call being ready for reaping
 507  */
 508 static void rxrpc_dead_call_expired(unsigned long _call)
 509 {
 510         struct rxrpc_call *call = (struct rxrpc_call *) _call;
 511
 512         _enter("{%d}", call->debug_id);
 513
 514         write_lock_bh(&call->state_lock);
 515         call->state = RXRPC_CALL_DEAD;
 516         write_unlock_bh(&call->state_lock);
 517         rxrpc_put_call(call);
 518 }
 519
 520 /*
 521  * mark a call as to be released, aborting it if it's still in progress
 522  * - called with softirqs disabled
 523  */
 524 static void rxrpc_mark_call_released(struct rxrpc_call *call)
 525 {
 526         bool sched;
 527
 528         write_lock(&call->state_lock);
 529         if (call->state < RXRPC_CALL_DEAD) {
 530                 sched = false;
 531                 if (call->state < RXRPC_CALL_COMPLETE) {
 532                         _debug("abort call %p", call);
 533                         call->state = RXRPC_CALL_LOCALLY_ABORTED;
 534                         call->abort_code = RX_CALL_DEAD;
 535                         if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events))
 536                                 sched = true;
 537                 }
 538                 if (!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
 539                         sched = true;
 540                 if (sched)
 541                         schedule_work(&call->processor);
 542         }
 543         write_unlock(&call->state_lock);
 544 }
 545
 546 /*
 547  * release all the calls associated with a socket
 548  */
 549 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 550 {
 551         struct rxrpc_call *call;
 552         struct rb_node *p;
 553
 554         _enter("%p", rx);
 555
 556         read_lock_bh(&rx->call_lock);
 557
 558         /* mark all the calls as no longer wanting incoming packets */
 559         for (p = rb_first(&rx->calls); p; p = rb_next(p)) {
 560                 call = rb_entry(p, struct rxrpc_call, sock_node);
 561                 rxrpc_mark_call_released(call);
 562         }
 563
 564         /* kill the not-yet-accepted incoming calls */
 565         list_for_each_entry(call, &rx->secureq, accept_link) {
 566                 rxrpc_mark_call_released(call);
 567         }
 568
 569         list_for_each_entry(call, &rx->acceptq, accept_link) {
 570                 rxrpc_mark_call_released(call);
 571         }
 572
 573         read_unlock_bh(&rx->call_lock);
 574         _leave("");
 575 }
 576
 577 /*
 578  * release a call
 579  */
 580 void __rxrpc_put_call(struct rxrpc_call *call)
 581 {
 582         ASSERT(call != NULL);
 583
 584         _enter("%p{u=%d}", call, atomic_read(&call->usage));
 585
 586         ASSERTCMP(atomic_read(&call->usage), >, 0);
 587
 588         if (atomic_dec_and_test(&call->usage)) {
 589                 _debug("call %d dead", call->debug_id);
 590                 ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
 591                 schedule_work(&call->destroyer);
 592         }
 593         _leave("");
 594 }
 595
 596 /*
 597  * clean up a call
 598  */
 599 static void rxrpc_cleanup_call(struct rxrpc_call *call)
 600 {
 601         _net("DESTROY CALL %d", call->debug_id);
 602
 603         ASSERT(call->socket);
 604
 605         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 606
 607         del_timer_sync(&call->lifetimer);
 608         del_timer_sync(&call->deadspan);
 609         del_timer_sync(&call->ack_timer);
 610         del_timer_sync(&call->resend_timer);
 611
 612         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 613         ASSERTCMP(call->events, ==, 0);
 614         if (work_pending(&call->processor)) {
 615                 _debug("defer destroy");
 616                 schedule_work(&call->destroyer);
 617                 return;
 618         }
 619
 620         if (call->conn) {
 621                 spin_lock(&call->conn->trans->peer->lock);
 622                 list_del(&call->error_link);
 623                 spin_unlock(&call->conn->trans->peer->lock);
 624
 625                 write_lock_bh(&call->conn->lock);
 626                 rb_erase(&call->conn_node, &call->conn->calls);
 627                 write_unlock_bh(&call->conn->lock);
 628                 rxrpc_put_connection(call->conn);
 629         }
 630
 631         if (call->acks_window) {
 632                 _debug("kill Tx window %d",
 633                        CIRC_CNT(call->acks_head, call->acks_tail,
 634                                 call->acks_winsz));
 635                 smp_mb();
 636                 while (CIRC_CNT(call->acks_head, call->acks_tail,
 637                                 call->acks_winsz) > 0) {
 638                         struct rxrpc_skb_priv *sp;
 639                         unsigned long _skb;
 640
 641                         _skb = call->acks_window[call->acks_tail] & ~1;
 642                         sp = rxrpc_skb((struct sk_buff *) _skb);
 643                         _debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
 644                         rxrpc_free_skb((struct sk_buff *) _skb);
 645                         call->acks_tail =
 646                                 (call->acks_tail + 1) & (call->acks_winsz - 1);
 647                 }
 648
 649                 kfree(call->acks_window);
 650         }
 651
 652         rxrpc_free_skb(call->tx_pending);
 653
 654         rxrpc_purge_queue(&call->rx_queue);
 655         ASSERT(skb_queue_empty(&call->rx_oos_queue));
 656         sock_put(&call->socket->sk);
 657         kmem_cache_free(rxrpc_call_jar, call);
 658 }
 659
 660 /*
 661  * destroy a call
 662  */
 663 static void rxrpc_destroy_call(struct work_struct *work)
 664 {
 665         struct rxrpc_call *call =
 666                 container_of(work, struct rxrpc_call, destroyer);
 667
 668         _enter("%p{%d,%d,%p}",
 669                call, atomic_read(&call->usage), call->channel, call->conn);
 670
 671         ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
 672
 673         write_lock_bh(&rxrpc_call_lock);
 674         list_del_init(&call->link);
 675         write_unlock_bh(&rxrpc_call_lock);
 676
 677         rxrpc_cleanup_call(call);
 678         _leave("");
 679 }
 680
 681 /*
 682  * preemptively destroy all the call records from a transport endpoint rather
 683  * than waiting for them to time out
 684  */
 685 void __exit rxrpc_destroy_all_calls(void)
 686 {
 687         struct rxrpc_call *call;
 688
 689         _enter("");
 690         write_lock_bh(&rxrpc_call_lock);
 691
 692         while (!list_empty(&rxrpc_calls)) {
 693                 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
 694                 _debug("Zapping call %p", call);
 695
 696                 list_del_init(&call->link);
 697
 698                 switch (atomic_read(&call->usage)) {
 699                 case 0:
 700                         ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
 701                         break;
 702                 case 1:
 703                         if (del_timer_sync(&call->deadspan) != 0 &&
 704                             call->state != RXRPC_CALL_DEAD)
 705                                 rxrpc_dead_call_expired((unsigned long) call);
 706                         if (call->state != RXRPC_CALL_DEAD)
 707                                 break;
 708                 default:
 709                         printk(KERN_ERR "RXRPC:"
 710                                " Call %p still in use (%d,%d,%s,%lx,%lx)!\n",
 711                                call, atomic_read(&call->usage),
 712                                atomic_read(&call->ackr_not_idle),
 713                                rxrpc_call_states[call->state],
 714                                call->flags, call->events);
 715                         if (!skb_queue_empty(&call->rx_queue))
 716                                 printk(KERN_ERR"RXRPC: Rx queue occupied\n");
 717                         if (!skb_queue_empty(&call->rx_oos_queue))
 718                                 printk(KERN_ERR"RXRPC: OOS queue occupied\n");
 719                         break;
 720                 }
 721
 722                 write_unlock_bh(&rxrpc_call_lock);
 723                 cond_resched();
 724                 write_lock_bh(&rxrpc_call_lock);
 725         }
 726
 727         write_unlock_bh(&rxrpc_call_lock);
 728         _leave("");
 729 }
 730
 731 /*
 732  * handle call lifetime being exceeded
 733  */
 734 static void rxrpc_call_life_expired(unsigned long _call)
 735 {
 736         struct rxrpc_call *call = (struct rxrpc_call *) _call;
 737
 738         if (call->state >= RXRPC_CALL_COMPLETE)
 739                 return;
 740
 741         _enter("{%d}", call->debug_id);
 742         read_lock_bh(&call->state_lock);
 743         if (call->state < RXRPC_CALL_COMPLETE) {
 744                 set_bit(RXRPC_CALL_LIFE_TIMER, &call->events);
 745                 schedule_work(&call->processor);
 746         }
 747         read_unlock_bh(&call->state_lock);
 748 }
 749
 750 /*
 751  * handle resend timer expiry
 752  */
 753 static void rxrpc_resend_time_expired(unsigned long _call)
 754 {
 755         struct rxrpc_call *call = (struct rxrpc_call *) _call;
 756
 757         _enter("{%d}", call->debug_id);
 758
 759         if (call->state >= RXRPC_CALL_COMPLETE)
 760                 return;
 761
 762         read_lock_bh(&call->state_lock);
 763         clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
 764         if (call->state < RXRPC_CALL_COMPLETE &&
 765             !test_and_set_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
 766                 schedule_work(&call->processor);
 767         read_unlock_bh(&call->state_lock);
 768 }
 769
 770 /*
 771  * handle ACK timer expiry
 772  */
 773 static void rxrpc_ack_time_expired(unsigned long _call)
 774 {
 775         struct rxrpc_call *call = (struct rxrpc_call *) _call;
 776
 777         _enter("{%d}", call->debug_id);
 778
 779         if (call->state >= RXRPC_CALL_COMPLETE)
 780                 return;
 781
 782         read_lock_bh(&call->state_lock);
 783         if (call->state < RXRPC_CALL_COMPLETE &&
 784             !test_and_set_bit(RXRPC_CALL_ACK, &call->events))
 785                 schedule_work(&call->processor);
 786         read_unlock_bh(&call->state_lock);
 787 }