net/rxrpc/call_object.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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <linux/circ_buf.h>
  17 #include <linux/spinlock_types.h>
  18 #include <net/sock.h>
  19 #include <net/af_rxrpc.h>
  20 #include "ar-internal.h"
  21
  22 /*
  23  * Maximum lifetime of a call (in jiffies).
  24  */
  25 unsigned int rxrpc_max_call_lifetime = 60 * HZ;
  26
  27 /*
  28  * Time till dead call expires after last use (in jiffies).
  29  */
  30 unsigned int rxrpc_dead_call_expiry = 2 * HZ;
  31
  32 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
  33         [RXRPC_CALL_UNINITIALISED]              = "Uninit",
  34         [RXRPC_CALL_CLIENT_AWAIT_CONN]          = "ClWtConn",
  35         [RXRPC_CALL_CLIENT_SEND_REQUEST]        = "ClSndReq",
  36         [RXRPC_CALL_CLIENT_AWAIT_REPLY]         = "ClAwtRpl",
  37         [RXRPC_CALL_CLIENT_RECV_REPLY]          = "ClRcvRpl",
  38         [RXRPC_CALL_CLIENT_FINAL_ACK]           = "ClFnlACK",
  39         [RXRPC_CALL_SERVER_SECURING]            = "SvSecure",
  40         [RXRPC_CALL_SERVER_ACCEPTING]           = "SvAccept",
  41         [RXRPC_CALL_SERVER_RECV_REQUEST]        = "SvRcvReq",
  42         [RXRPC_CALL_SERVER_ACK_REQUEST]         = "SvAckReq",
  43         [RXRPC_CALL_SERVER_SEND_REPLY]          = "SvSndRpl",
  44         [RXRPC_CALL_SERVER_AWAIT_ACK]           = "SvAwtACK",
  45         [RXRPC_CALL_COMPLETE]                   = "Complete",
  46         [RXRPC_CALL_SERVER_BUSY]                = "SvBusy  ",
  47         [RXRPC_CALL_REMOTELY_ABORTED]           = "RmtAbort",
  48         [RXRPC_CALL_LOCALLY_ABORTED]            = "LocAbort",
  49         [RXRPC_CALL_NETWORK_ERROR]              = "NetError",
  50         [RXRPC_CALL_DEAD]                       = "Dead    ",
  51 };
  52
  53 struct kmem_cache *rxrpc_call_jar;
  54 LIST_HEAD(rxrpc_calls);
  55 DEFINE_RWLOCK(rxrpc_call_lock);
  56
  57 static void rxrpc_destroy_call(struct work_struct *work);
  58 static void rxrpc_call_life_expired(unsigned long _call);
  59 static void rxrpc_dead_call_expired(unsigned long _call);
  60 static void rxrpc_ack_time_expired(unsigned long _call);
  61 static void rxrpc_resend_time_expired(unsigned long _call);
  62
  63 /*
  64  * find an extant server call
  65  * - called in process context with IRQs enabled
  66  */
  67 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
  68                                               unsigned long user_call_ID)
  69 {
  70         struct rxrpc_call *call;
  71         struct rb_node *p;
  72
  73         _enter("%p,%lx", rx, user_call_ID);
  74
  75         read_lock(&rx->call_lock);
  76
  77         p = rx->calls.rb_node;
  78         while (p) {
  79                 call = rb_entry(p, struct rxrpc_call, sock_node);
  80
  81                 if (user_call_ID < call->user_call_ID)
  82                         p = p->rb_left;
  83                 else if (user_call_ID > call->user_call_ID)
  84                         p = p->rb_right;
  85                 else
  86                         goto found_extant_call;
  87         }
  88
  89         read_unlock(&rx->call_lock);
  90         _leave(" = NULL");
  91         return NULL;
  92
  93 found_extant_call:
  94         rxrpc_get_call(call);
  95         read_unlock(&rx->call_lock);
  96         _leave(" = %p [%d]", call, atomic_read(&call->usage));
  97         return call;
  98 }
  99
 100 /*
 101  * allocate a new call
 102  */
 103 static struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
 104 {
 105         struct rxrpc_call *call;
 106
 107         call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
 108         if (!call)
 109                 return NULL;
 110
 111         call->acks_winsz = 16;
 112         call->acks_window = kmalloc(call->acks_winsz * sizeof(unsigned long),
 113                                     gfp);
 114         if (!call->acks_window) {
 115                 kmem_cache_free(rxrpc_call_jar, call);
 116                 return NULL;
 117         }
 118
 119         setup_timer(&call->lifetimer, &rxrpc_call_life_expired,
 120                     (unsigned long) call);
 121         setup_timer(&call->deadspan, &rxrpc_dead_call_expired,
 122                     (unsigned long) call);
 123         setup_timer(&call->ack_timer, &rxrpc_ack_time_expired,
 124                     (unsigned long) call);
 125         setup_timer(&call->resend_timer, &rxrpc_resend_time_expired,
 126                     (unsigned long) call);
 127         INIT_WORK(&call->destroyer, &rxrpc_destroy_call);
 128         INIT_WORK(&call->processor, &rxrpc_process_call);
 129         INIT_LIST_HEAD(&call->link);
 130         INIT_LIST_HEAD(&call->accept_link);
 131         skb_queue_head_init(&call->rx_queue);
 132         skb_queue_head_init(&call->rx_oos_queue);
 133         init_waitqueue_head(&call->tx_waitq);
 134         spin_lock_init(&call->lock);
 135         rwlock_init(&call->state_lock);
 136         atomic_set(&call->usage, 1);
 137         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
 138
 139         memset(&call->sock_node, 0xed, sizeof(call->sock_node));
 140
 141         call->rx_data_expect = 1;
 142         call->rx_data_eaten = 0;
 143         call->rx_first_oos = 0;
 144         call->ackr_win_top = call->rx_data_eaten + 1 + rxrpc_rx_window_size;
 145         call->creation_jif = jiffies;
 146         return call;
 147 }
 148
 149 /*
 150  * Allocate a new client call.
 151  */
 152 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
 153                                                   struct sockaddr_rxrpc *srx,
 154                                                   gfp_t gfp)
 155 {
 156         struct rxrpc_call *call;
 157
 158         _enter("");
 159
 160         ASSERT(rx->local != NULL);
 161
 162         call = rxrpc_alloc_call(gfp);
 163         if (!call)
 164                 return ERR_PTR(-ENOMEM);
 165         call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
 166
 167         sock_hold(&rx->sk);
 168         call->socket = rx;
 169         call->rx_data_post = 1;
 170
 171         call->local = rx->local;
 172         call->service_id = srx->srx_service;
 173         call->in_clientflag = 0;
 174
 175         _leave(" = %p", call);
 176         return call;
 177 }
 178
 179 /*
 180  * Begin client call.
 181  */
 182 static int rxrpc_begin_client_call(struct rxrpc_call *call,
 183                                    struct rxrpc_conn_parameters *cp,
 184                                    struct sockaddr_rxrpc *srx,
 185                                    gfp_t gfp)
 186 {
 187         int ret;
 188
 189         /* Set up or get a connection record and set the protocol parameters,
 190          * including channel number and call ID.
 191          */
 192         ret = rxrpc_connect_call(call, cp, srx, gfp);
 193         if (ret < 0)
 194                 return ret;
 195
 196         call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
 197
 198         spin_lock(&call->conn->params.peer->lock);
 199         hlist_add_head(&call->error_link, &call->conn->params.peer->error_targets);
 200         spin_unlock(&call->conn->params.peer->lock);
 201
 202         call->lifetimer.expires = jiffies + rxrpc_max_call_lifetime;
 203         add_timer(&call->lifetimer);
 204         return 0;
 205 }
 206
 207 /*
 208  * set up a call for the given data
 209  * - called in process context with IRQs enabled
 210  */
 211 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 212                                          struct rxrpc_conn_parameters *cp,
 213                                          struct sockaddr_rxrpc *srx,
 214                                          unsigned long user_call_ID,
 215                                          gfp_t gfp)
 216 {
 217         struct rxrpc_call *call, *xcall;
 218         struct rb_node *parent, **pp;
 219         int ret;
 220
 221         _enter("%p,%lx", rx, user_call_ID);
 222
 223         call = rxrpc_alloc_client_call(rx, srx, gfp);
 224         if (IS_ERR(call)) {
 225                 _leave(" = %ld", PTR_ERR(call));
 226                 return call;
 227         }
 228
 229         /* Publish the call, even though it is incompletely set up as yet */
 230         call->user_call_ID = user_call_ID;
 231         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 232
 233         write_lock(&rx->call_lock);
 234
 235         pp = &rx->calls.rb_node;
 236         parent = NULL;
 237         while (*pp) {
 238                 parent = *pp;
 239                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 240
 241                 if (user_call_ID < xcall->user_call_ID)
 242                         pp = &(*pp)->rb_left;
 243                 else if (user_call_ID > xcall->user_call_ID)
 244                         pp = &(*pp)->rb_right;
 245                 else
 246                         goto found_user_ID_now_present;
 247         }
 248
 249         rxrpc_get_call(call);
 250
 251         rb_link_node(&call->sock_node, parent, pp);
 252         rb_insert_color(&call->sock_node, &rx->calls);
 253         write_unlock(&rx->call_lock);
 254
 255         write_lock_bh(&rxrpc_call_lock);
 256         list_add_tail(&call->link, &rxrpc_calls);
 257         write_unlock_bh(&rxrpc_call_lock);
 258
 259         ret = rxrpc_begin_client_call(call, cp, srx, gfp);
 260         if (ret < 0)
 261                 goto error;
 262
 263         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
 264
 265         _leave(" = %p [new]", call);
 266         return call;
 267
 268 error:
 269         write_lock(&rx->call_lock);
 270         rb_erase(&call->sock_node, &rx->calls);
 271         write_unlock(&rx->call_lock);
 272         rxrpc_put_call(call);
 273
 274         write_lock_bh(&rxrpc_call_lock);
 275         list_del_init(&call->link);
 276         write_unlock_bh(&rxrpc_call_lock);
 277
 278         call->state = RXRPC_CALL_DEAD;
 279         rxrpc_put_call(call);
 280         _leave(" = %d", ret);
 281         return ERR_PTR(ret);
 282
 283         /* We unexpectedly found the user ID in the list after taking
 284          * the call_lock.  This shouldn't happen unless the user races
 285          * with itself and tries to add the same user ID twice at the
 286          * same time in different threads.
 287          */
 288 found_user_ID_now_present:
 289         write_unlock(&rx->call_lock);
 290         call->state = RXRPC_CALL_DEAD;
 291         rxrpc_put_call(call);
 292         _leave(" = -EEXIST [%p]", call);
 293         return ERR_PTR(-EEXIST);
 294 }
 295
 296 /*
 297  * set up an incoming call
 298  * - called in process context with IRQs enabled
 299  */
 300 struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
 301                                        struct rxrpc_connection *conn,
 302                                        struct sk_buff *skb)
 303 {
 304         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 305         struct rxrpc_call *call, *candidate;
 306         u32 call_id, chan;
 307
 308         _enter(",%d", conn->debug_id);
 309
 310         ASSERT(rx != NULL);
 311
 312         candidate = rxrpc_alloc_call(GFP_NOIO);
 313         if (!candidate)
 314                 return ERR_PTR(-EBUSY);
 315
 316         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 317         candidate->socket       = rx;
 318         candidate->conn         = conn;
 319         candidate->cid          = sp->hdr.cid;
 320         candidate->call_id      = sp->hdr.callNumber;
 321         candidate->channel      = chan;
 322         candidate->rx_data_post = 0;
 323         candidate->state        = RXRPC_CALL_SERVER_ACCEPTING;
 324         if (conn->security_ix > 0)
 325                 candidate->state = RXRPC_CALL_SERVER_SECURING;
 326
 327         spin_lock(&conn->channel_lock);
 328
 329         /* set the channel for this call */
 330         call = rcu_dereference_protected(conn->channels[chan].call,
 331                                          lockdep_is_held(&conn->channel_lock));
 332
 333         _debug("channel[%u] is %p", candidate->channel, call);
 334         if (call && call->call_id == sp->hdr.callNumber) {
 335                 /* already set; must've been a duplicate packet */
 336                 _debug("extant call [%d]", call->state);
 337                 ASSERTCMP(call->conn, ==, conn);
 338
 339                 read_lock(&call->state_lock);
 340                 switch (call->state) {
 341                 case RXRPC_CALL_LOCALLY_ABORTED:
 342                         if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events))
 343                                 rxrpc_queue_call(call);
 344                 case RXRPC_CALL_REMOTELY_ABORTED:
 345                         read_unlock(&call->state_lock);
 346                         goto aborted_call;
 347                 default:
 348                         rxrpc_get_call(call);
 349                         read_unlock(&call->state_lock);
 350                         goto extant_call;
 351                 }
 352         }
 353
 354         if (call) {
 355                 /* it seems the channel is still in use from the previous call
 356                  * - ditch the old binding if its call is now complete */
 357                 _debug("CALL: %u { %s }",
 358                        call->debug_id, rxrpc_call_states[call->state]);
 359
 360                 if (call->state >= RXRPC_CALL_COMPLETE) {
 361                         __rxrpc_disconnect_call(call);
 362                 } else {
 363                         spin_unlock(&conn->channel_lock);
 364                         kmem_cache_free(rxrpc_call_jar, candidate);
 365                         _leave(" = -EBUSY");
 366                         return ERR_PTR(-EBUSY);
 367                 }
 368         }
 369
 370         /* check the call number isn't duplicate */
 371         _debug("check dup");
 372         call_id = sp->hdr.callNumber;
 373
 374         /* We just ignore calls prior to the current call ID.  Terminated calls
 375          * are handled via the connection.
 376          */
 377         if (call_id <= conn->channels[chan].call_counter)
 378                 goto old_call; /* TODO: Just drop packet */
 379
 380         /* make the call available */
 381         _debug("new call");
 382         call = candidate;
 383         candidate = NULL;
 384         conn->channels[chan].call_counter = call_id;
 385         rcu_assign_pointer(conn->channels[chan].call, call);
 386         sock_hold(&rx->sk);
 387         rxrpc_get_connection(conn);
 388         spin_unlock(&conn->channel_lock);
 389
 390         spin_lock(&conn->params.peer->lock);
 391         hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
 392         spin_unlock(&conn->params.peer->lock);
 393
 394         write_lock_bh(&rxrpc_call_lock);
 395         list_add_tail(&call->link, &rxrpc_calls);
 396         write_unlock_bh(&rxrpc_call_lock);
 397
 398         call->local = conn->params.local;
 399         call->epoch = conn->proto.epoch;
 400         call->service_id = conn->params.service_id;
 401         call->in_clientflag = RXRPC_CLIENT_INITIATED;
 402
 403         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
 404
 405         call->lifetimer.expires = jiffies + rxrpc_max_call_lifetime;
 406         add_timer(&call->lifetimer);
 407         _leave(" = %p {%d} [new]", call, call->debug_id);
 408         return call;
 409
 410 extant_call:
 411         spin_unlock(&conn->channel_lock);
 412         kmem_cache_free(rxrpc_call_jar, candidate);
 413         _leave(" = %p {%d} [extant]", call, call ? call->debug_id : -1);
 414         return call;
 415
 416 aborted_call:
 417         spin_unlock(&conn->channel_lock);
 418         kmem_cache_free(rxrpc_call_jar, candidate);
 419         _leave(" = -ECONNABORTED");
 420         return ERR_PTR(-ECONNABORTED);
 421
 422 old_call:
 423         spin_unlock(&conn->channel_lock);
 424         kmem_cache_free(rxrpc_call_jar, candidate);
 425         _leave(" = -ECONNRESET [old]");
 426         return ERR_PTR(-ECONNRESET);
 427 }
 428
 429 /*
 430  * detach a call from a socket and set up for release
 431  */
 432 void rxrpc_release_call(struct rxrpc_call *call)
 433 {
 434         struct rxrpc_connection *conn = call->conn;
 435         struct rxrpc_sock *rx = call->socket;
 436
 437         _enter("{%d,%d,%d,%d}",
 438                call->debug_id, atomic_read(&call->usage),
 439                atomic_read(&call->ackr_not_idle),
 440                call->rx_first_oos);
 441
 442         spin_lock_bh(&call->lock);
 443         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 444                 BUG();
 445         spin_unlock_bh(&call->lock);
 446
 447         /* dissociate from the socket
 448          * - the socket's ref on the call is passed to the death timer
 449          */
 450         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
 451
 452         spin_lock(&conn->params.peer->lock);
 453         hlist_del_init(&call->error_link);
 454         spin_unlock(&conn->params.peer->lock);
 455
 456         write_lock_bh(&rx->call_lock);
 457         if (!list_empty(&call->accept_link)) {
 458                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 459                        call, call->events, call->flags);
 460                 ASSERT(!test_bit(RXRPC_CALL_HAS_USERID, &call->flags));
 461                 list_del_init(&call->accept_link);
 462                 sk_acceptq_removed(&rx->sk);
 463         } else if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 464                 rb_erase(&call->sock_node, &rx->calls);
 465                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 466                 clear_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 467         }
 468         write_unlock_bh(&rx->call_lock);
 469
 470         /* free up the channel for reuse */
 471         write_lock_bh(&call->state_lock);
 472
 473         if (call->state < RXRPC_CALL_COMPLETE &&
 474             call->state != RXRPC_CALL_CLIENT_FINAL_ACK) {
 475                 _debug("+++ ABORTING STATE %d +++\n", call->state);
 476                 call->state = RXRPC_CALL_LOCALLY_ABORTED;
 477                 call->local_abort = RX_CALL_DEAD;
 478         }
 479         write_unlock_bh(&call->state_lock);
 480
 481         rxrpc_disconnect_call(call);
 482
 483         /* clean up the Rx queue */
 484         if (!skb_queue_empty(&call->rx_queue) ||
 485             !skb_queue_empty(&call->rx_oos_queue)) {
 486                 struct rxrpc_skb_priv *sp;
 487                 struct sk_buff *skb;
 488
 489                 _debug("purge Rx queues");
 490
 491                 spin_lock_bh(&call->lock);
 492                 while ((skb = skb_dequeue(&call->rx_queue)) ||
 493                        (skb = skb_dequeue(&call->rx_oos_queue))) {
 494                         spin_unlock_bh(&call->lock);
 495
 496                         sp = rxrpc_skb(skb);
 497                         _debug("- zap %s %%%u #%u",
 498                                rxrpc_pkts[sp->hdr.type],
 499                                sp->hdr.serial, sp->hdr.seq);
 500                         rxrpc_free_skb(skb);
 501                         spin_lock_bh(&call->lock);
 502                 }
 503                 spin_unlock_bh(&call->lock);
 504
 505                 ASSERTCMP(call->state, !=, RXRPC_CALL_COMPLETE);
 506         }
 507
 508         del_timer_sync(&call->resend_timer);
 509         del_timer_sync(&call->ack_timer);
 510         del_timer_sync(&call->lifetimer);
 511         call->deadspan.expires = jiffies + rxrpc_dead_call_expiry;
 512         add_timer(&call->deadspan);
 513
 514         _leave("");
 515 }
 516
 517 /*
 518  * handle a dead call being ready for reaping
 519  */
 520 static void rxrpc_dead_call_expired(unsigned long _call)
 521 {
 522         struct rxrpc_call *call = (struct rxrpc_call *) _call;
 523
 524         _enter("{%d}", call->debug_id);
 525
 526         write_lock_bh(&call->state_lock);
 527         call->state = RXRPC_CALL_DEAD;
 528         write_unlock_bh(&call->state_lock);
 529         rxrpc_put_call(call);
 530 }
 531
 532 /*
 533  * mark a call as to be released, aborting it if it's still in progress
 534  * - called with softirqs disabled
 535  */
 536 static void rxrpc_mark_call_released(struct rxrpc_call *call)
 537 {
 538         bool sched;
 539
 540         write_lock(&call->state_lock);
 541         if (call->state < RXRPC_CALL_DEAD) {
 542                 sched = false;
 543                 if (call->state < RXRPC_CALL_COMPLETE) {
 544                         _debug("abort call %p", call);
 545                         call->state = RXRPC_CALL_LOCALLY_ABORTED;
 546                         call->local_abort = RX_CALL_DEAD;
 547                         if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events))
 548                                 sched = true;
 549                 }
 550                 if (!test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events))
 551                         sched = true;
 552                 if (sched)
 553                         rxrpc_queue_call(call);
 554         }
 555         write_unlock(&call->state_lock);
 556 }
 557
 558 /*
 559  * release all the calls associated with a socket
 560  */
 561 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 562 {
 563         struct rxrpc_call *call;
 564         struct rb_node *p;
 565
 566         _enter("%p", rx);
 567
 568         read_lock_bh(&rx->call_lock);
 569
 570         /* mark all the calls as no longer wanting incoming packets */
 571         for (p = rb_first(&rx->calls); p; p = rb_next(p)) {
 572                 call = rb_entry(p, struct rxrpc_call, sock_node);
 573                 rxrpc_mark_call_released(call);
 574         }
 575
 576         /* kill the not-yet-accepted incoming calls */
 577         list_for_each_entry(call, &rx->secureq, accept_link) {
 578                 rxrpc_mark_call_released(call);
 579         }
 580
 581         list_for_each_entry(call, &rx->acceptq, accept_link) {
 582                 rxrpc_mark_call_released(call);
 583         }
 584
 585         read_unlock_bh(&rx->call_lock);
 586         _leave("");
 587 }
 588
 589 /*
 590  * release a call
 591  */
 592 void __rxrpc_put_call(struct rxrpc_call *call)
 593 {
 594         ASSERT(call != NULL);
 595
 596         _enter("%p{u=%d}", call, atomic_read(&call->usage));
 597
 598         ASSERTCMP(atomic_read(&call->usage), >, 0);
 599
 600         if (atomic_dec_and_test(&call->usage)) {
 601                 _debug("call %d dead", call->debug_id);
 602                 WARN_ON(atomic_read(&call->skb_count) != 0);
 603                 ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
 604                 rxrpc_queue_work(&call->destroyer);
 605         }
 606         _leave("");
 607 }
 608
 609 /*
 610  * Final call destruction under RCU.
 611  */
 612 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
 613 {
 614         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 615
 616         rxrpc_purge_queue(&call->rx_queue);
 617         kmem_cache_free(rxrpc_call_jar, call);
 618 }
 619
 620 /*
 621  * clean up a call
 622  */
 623 static void rxrpc_cleanup_call(struct rxrpc_call *call)
 624 {
 625         _net("DESTROY CALL %d", call->debug_id);
 626
 627         ASSERT(call->socket);
 628
 629         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 630
 631         del_timer_sync(&call->lifetimer);
 632         del_timer_sync(&call->deadspan);
 633         del_timer_sync(&call->ack_timer);
 634         del_timer_sync(&call->resend_timer);
 635
 636         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 637         ASSERTCMP(call->events, ==, 0);
 638         if (work_pending(&call->processor)) {
 639                 _debug("defer destroy");
 640                 rxrpc_queue_work(&call->destroyer);
 641                 return;
 642         }
 643
 644         ASSERTCMP(call->conn, ==, NULL);
 645
 646         if (call->acks_window) {
 647                 _debug("kill Tx window %d",
 648                        CIRC_CNT(call->acks_head, call->acks_tail,
 649                                 call->acks_winsz));
 650                 smp_mb();
 651                 while (CIRC_CNT(call->acks_head, call->acks_tail,
 652                                 call->acks_winsz) > 0) {
 653                         struct rxrpc_skb_priv *sp;
 654                         unsigned long _skb;
 655
 656                         _skb = call->acks_window[call->acks_tail] & ~1;
 657                         sp = rxrpc_skb((struct sk_buff *)_skb);
 658                         _debug("+++ clear Tx %u", sp->hdr.seq);
 659                         rxrpc_free_skb((struct sk_buff *)_skb);
 660                         call->acks_tail =
 661                                 (call->acks_tail + 1) & (call->acks_winsz - 1);
 662                 }
 663
 664                 kfree(call->acks_window);
 665         }
 666
 667         rxrpc_free_skb(call->tx_pending);
 668
 669         rxrpc_purge_queue(&call->rx_queue);
 670         ASSERT(skb_queue_empty(&call->rx_oos_queue));
 671         sock_put(&call->socket->sk);
 672         call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
 673 }
 674
 675 /*
 676  * destroy a call
 677  */
 678 static void rxrpc_destroy_call(struct work_struct *work)
 679 {
 680         struct rxrpc_call *call =
 681                 container_of(work, struct rxrpc_call, destroyer);
 682
 683         _enter("%p{%d,%d,%p}",
 684                call, atomic_read(&call->usage), call->channel, call->conn);
 685
 686         ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
 687
 688         write_lock_bh(&rxrpc_call_lock);
 689         list_del_init(&call->link);
 690         write_unlock_bh(&rxrpc_call_lock);
 691
 692         rxrpc_cleanup_call(call);
 693         _leave("");
 694 }
 695
 696 /*
 697  * preemptively destroy all the call records from a transport endpoint rather
 698  * than waiting for them to time out
 699  */
 700 void __exit rxrpc_destroy_all_calls(void)
 701 {
 702         struct rxrpc_call *call;
 703
 704         _enter("");
 705         write_lock_bh(&rxrpc_call_lock);
 706
 707         while (!list_empty(&rxrpc_calls)) {
 708                 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
 709                 _debug("Zapping call %p", call);
 710
 711                 list_del_init(&call->link);
 712
 713                 switch (atomic_read(&call->usage)) {
 714                 case 0:
 715                         ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
 716                         break;
 717                 case 1:
 718                         if (del_timer_sync(&call->deadspan) != 0 &&
 719                             call->state != RXRPC_CALL_DEAD)
 720                                 rxrpc_dead_call_expired((unsigned long) call);
 721                         if (call->state != RXRPC_CALL_DEAD)
 722                                 break;
 723                 default:
 724                         pr_err("Call %p still in use (%d,%d,%s,%lx,%lx)!\n",
 725                                call, atomic_read(&call->usage),
 726                                atomic_read(&call->ackr_not_idle),
 727                                rxrpc_call_states[call->state],
 728                                call->flags, call->events);
 729                         if (!skb_queue_empty(&call->rx_queue))
 730                                 pr_err("Rx queue occupied\n");
 731                         if (!skb_queue_empty(&call->rx_oos_queue))
 732                                 pr_err("OOS queue occupied\n");
 733                         break;
 734                 }
 735
 736                 write_unlock_bh(&rxrpc_call_lock);
 737                 cond_resched();
 738                 write_lock_bh(&rxrpc_call_lock);
 739         }
 740
 741         write_unlock_bh(&rxrpc_call_lock);
 742         _leave("");
 743 }
 744
 745 /*
 746  * handle call lifetime being exceeded
 747  */
 748 static void rxrpc_call_life_expired(unsigned long _call)
 749 {
 750         struct rxrpc_call *call = (struct rxrpc_call *) _call;
 751
 752         if (call->state >= RXRPC_CALL_COMPLETE)
 753                 return;
 754
 755         _enter("{%d}", call->debug_id);
 756         read_lock_bh(&call->state_lock);
 757         if (call->state < RXRPC_CALL_COMPLETE) {
 758                 set_bit(RXRPC_CALL_EV_LIFE_TIMER, &call->events);
 759                 rxrpc_queue_call(call);
 760         }
 761         read_unlock_bh(&call->state_lock);
 762 }
 763
 764 /*
 765  * handle resend timer expiry
 766  * - may not take call->state_lock as this can deadlock against del_timer_sync()
 767  */
 768 static void rxrpc_resend_time_expired(unsigned long _call)
 769 {
 770         struct rxrpc_call *call = (struct rxrpc_call *) _call;
 771
 772         _enter("{%d}", call->debug_id);
 773
 774         if (call->state >= RXRPC_CALL_COMPLETE)
 775                 return;
 776
 777         clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
 778         if (!test_and_set_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events))
 779                 rxrpc_queue_call(call);
 780 }
 781
 782 /*
 783  * handle ACK timer expiry
 784  */
 785 static void rxrpc_ack_time_expired(unsigned long _call)
 786 {
 787         struct rxrpc_call *call = (struct rxrpc_call *) _call;
 788
 789         _enter("{%d}", call->debug_id);
 790
 791         if (call->state >= RXRPC_CALL_COMPLETE)
 792                 return;
 793
 794         read_lock_bh(&call->state_lock);
 795         if (call->state < RXRPC_CALL_COMPLETE &&
 796             !test_and_set_bit(RXRPC_CALL_EV_ACK, &call->events))
 797                 rxrpc_queue_call(call);
 798         read_unlock_bh(&call->state_lock);
 799 }