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 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
  23         [RXRPC_CALL_UNINITIALISED]              = "Uninit  ",
  24         [RXRPC_CALL_CLIENT_AWAIT_CONN]          = "ClWtConn",
  25         [RXRPC_CALL_CLIENT_SEND_REQUEST]        = "ClSndReq",
  26         [RXRPC_CALL_CLIENT_AWAIT_REPLY]         = "ClAwtRpl",
  27         [RXRPC_CALL_CLIENT_RECV_REPLY]          = "ClRcvRpl",
  28         [RXRPC_CALL_SERVER_PREALLOC]            = "SvPrealc",
  29         [RXRPC_CALL_SERVER_SECURING]            = "SvSecure",
  30         [RXRPC_CALL_SERVER_ACCEPTING]           = "SvAccept",
  31         [RXRPC_CALL_SERVER_RECV_REQUEST]        = "SvRcvReq",
  32         [RXRPC_CALL_SERVER_ACK_REQUEST]         = "SvAckReq",
  33         [RXRPC_CALL_SERVER_SEND_REPLY]          = "SvSndRpl",
  34         [RXRPC_CALL_SERVER_AWAIT_ACK]           = "SvAwtACK",
  35         [RXRPC_CALL_COMPLETE]                   = "Complete",
  36 };
  37
  38 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
  39         [RXRPC_CALL_SUCCEEDED]                  = "Complete",
  40         [RXRPC_CALL_REMOTELY_ABORTED]           = "RmtAbort",
  41         [RXRPC_CALL_LOCALLY_ABORTED]            = "LocAbort",
  42         [RXRPC_CALL_LOCAL_ERROR]                = "LocError",
  43         [RXRPC_CALL_NETWORK_ERROR]              = "NetError",
  44 };
  45
  46 struct kmem_cache *rxrpc_call_jar;
  47
  48 static void rxrpc_call_timer_expired(struct timer_list *t)
  49 {
  50         struct rxrpc_call *call = from_timer(call, t, timer);
  51
  52         _enter("%d", call->debug_id);
  53
  54         if (call->state < RXRPC_CALL_COMPLETE) {
  55                 trace_rxrpc_timer(call, rxrpc_timer_expired, jiffies);
  56                 rxrpc_queue_call(call);
  57         }
  58 }
  59
  60 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
  61
  62 /*
  63  * find an extant server call
  64  * - called in process context with IRQs enabled
  65  */
  66 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
  67                                               unsigned long user_call_ID)
  68 {
  69         struct rxrpc_call *call;
  70         struct rb_node *p;
  71
  72         _enter("%p,%lx", rx, user_call_ID);
  73
  74         read_lock(&rx->call_lock);
  75
  76         p = rx->calls.rb_node;
  77         while (p) {
  78                 call = rb_entry(p, struct rxrpc_call, sock_node);
  79
  80                 if (user_call_ID < call->user_call_ID)
  81                         p = p->rb_left;
  82                 else if (user_call_ID > call->user_call_ID)
  83                         p = p->rb_right;
  84                 else
  85                         goto found_extant_call;
  86         }
  87
  88         read_unlock(&rx->call_lock);
  89         _leave(" = NULL");
  90         return NULL;
  91
  92 found_extant_call:
  93         rxrpc_get_call(call, rxrpc_call_got);
  94         read_unlock(&rx->call_lock);
  95         _leave(" = %p [%d]", call, atomic_read(&call->usage));
  96         return call;
  97 }
  98
  99 /*
 100  * allocate a new call
 101  */
 102 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
 103                                     unsigned int debug_id)
 104 {
 105         struct rxrpc_call *call;
 106         struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
 107
 108         call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
 109         if (!call)
 110                 return NULL;
 111
 112         call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
 113                                     sizeof(struct sk_buff *),
 114                                     gfp);
 115         if (!call->rxtx_buffer)
 116                 goto nomem;
 117
 118         call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
 119         if (!call->rxtx_annotations)
 120                 goto nomem_2;
 121
 122         mutex_init(&call->user_mutex);
 123
 124         /* Prevent lockdep reporting a deadlock false positive between the afs
 125          * filesystem and sys_sendmsg() via the mmap sem.
 126          */
 127         if (rx->sk.sk_kern_sock)
 128                 lockdep_set_class(&call->user_mutex,
 129                                   &rxrpc_call_user_mutex_lock_class_key);
 130
 131         timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
 132         INIT_WORK(&call->processor, &rxrpc_process_call);
 133         INIT_LIST_HEAD(&call->link);
 134         INIT_LIST_HEAD(&call->chan_wait_link);
 135         INIT_LIST_HEAD(&call->accept_link);
 136         INIT_LIST_HEAD(&call->recvmsg_link);
 137         INIT_LIST_HEAD(&call->sock_link);
 138         init_waitqueue_head(&call->waitq);
 139         spin_lock_init(&call->lock);
 140         spin_lock_init(&call->notify_lock);
 141         spin_lock_init(&call->input_lock);
 142         rwlock_init(&call->state_lock);
 143         atomic_set(&call->usage, 1);
 144         call->debug_id = debug_id;
 145         call->tx_total_len = -1;
 146         call->next_rx_timo = 20 * HZ;
 147         call->next_req_timo = 1 * HZ;
 148
 149         memset(&call->sock_node, 0xed, sizeof(call->sock_node));
 150
 151         /* Leave space in the ring to handle a maxed-out jumbo packet */
 152         call->rx_winsize = rxrpc_rx_window_size;
 153         call->tx_winsize = 16;
 154         call->rx_expect_next = 1;
 155
 156         call->cong_cwnd = 2;
 157         call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
 158
 159         call->rxnet = rxnet;
 160         atomic_inc(&rxnet->nr_calls);
 161         return call;
 162
 163 nomem_2:
 164         kfree(call->rxtx_buffer);
 165 nomem:
 166         kmem_cache_free(rxrpc_call_jar, call);
 167         return NULL;
 168 }
 169
 170 /*
 171  * Allocate a new client call.
 172  */
 173 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
 174                                                   struct sockaddr_rxrpc *srx,
 175                                                   gfp_t gfp,
 176                                                   unsigned int debug_id)
 177 {
 178         struct rxrpc_call *call;
 179         ktime_t now;
 180
 181         _enter("");
 182
 183         call = rxrpc_alloc_call(rx, gfp, debug_id);
 184         if (!call)
 185                 return ERR_PTR(-ENOMEM);
 186         call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
 187         call->service_id = srx->srx_service;
 188         call->tx_phase = true;
 189         now = ktime_get_real();
 190         call->acks_latest_ts = now;
 191         call->cong_tstamp = now;
 192
 193         _leave(" = %p", call);
 194         return call;
 195 }
 196
 197 /*
 198  * Initiate the call ack/resend/expiry timer.
 199  */
 200 static void rxrpc_start_call_timer(struct rxrpc_call *call)
 201 {
 202         unsigned long now = jiffies;
 203         unsigned long j = now + MAX_JIFFY_OFFSET;
 204
 205         call->ack_at = j;
 206         call->ack_lost_at = j;
 207         call->resend_at = j;
 208         call->ping_at = j;
 209         call->expect_rx_by = j;
 210         call->expect_req_by = j;
 211         call->expect_term_by = j;
 212         call->timer.expires = now;
 213 }
 214
 215 /*
 216  * Set up a call for the given parameters.
 217  * - Called with the socket lock held, which it must release.
 218  * - If it returns a call, the call's lock will need releasing by the caller.
 219  */
 220 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 221                                          struct rxrpc_conn_parameters *cp,
 222                                          struct sockaddr_rxrpc *srx,
 223                                          struct rxrpc_call_params *p,
 224                                          gfp_t gfp,
 225                                          unsigned int debug_id)
 226         __releases(&rx->sk.sk_lock.slock)
 227         __acquires(&call->user_mutex)
 228 {
 229         struct rxrpc_call *call, *xcall;
 230         struct rxrpc_net *rxnet;
 231         struct rb_node *parent, **pp;
 232         const void *here = __builtin_return_address(0);
 233         int ret;
 234
 235         _enter("%p,%lx", rx, p->user_call_ID);
 236
 237         call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
 238         if (IS_ERR(call)) {
 239                 release_sock(&rx->sk);
 240                 _leave(" = %ld", PTR_ERR(call));
 241                 return call;
 242         }
 243
 244         call->tx_total_len = p->tx_total_len;
 245         trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage),
 246                          here, (const void *)p->user_call_ID);
 247
 248         /* We need to protect a partially set up call against the user as we
 249          * will be acting outside the socket lock.
 250          */
 251         mutex_lock(&call->user_mutex);
 252
 253         /* Publish the call, even though it is incompletely set up as yet */
 254         write_lock(&rx->call_lock);
 255
 256         pp = &rx->calls.rb_node;
 257         parent = NULL;
 258         while (*pp) {
 259                 parent = *pp;
 260                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 261
 262                 if (p->user_call_ID < xcall->user_call_ID)
 263                         pp = &(*pp)->rb_left;
 264                 else if (p->user_call_ID > xcall->user_call_ID)
 265                         pp = &(*pp)->rb_right;
 266                 else
 267                         goto error_dup_user_ID;
 268         }
 269
 270         rcu_assign_pointer(call->socket, rx);
 271         call->user_call_ID = p->user_call_ID;
 272         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 273         rxrpc_get_call(call, rxrpc_call_got_userid);
 274         rb_link_node(&call->sock_node, parent, pp);
 275         rb_insert_color(&call->sock_node, &rx->calls);
 276         list_add(&call->sock_link, &rx->sock_calls);
 277
 278         write_unlock(&rx->call_lock);
 279
 280         rxnet = call->rxnet;
 281         write_lock(&rxnet->call_lock);
 282         list_add_tail(&call->link, &rxnet->calls);
 283         write_unlock(&rxnet->call_lock);
 284
 285         /* From this point on, the call is protected by its own lock. */
 286         release_sock(&rx->sk);
 287
 288         /* Set up or get a connection record and set the protocol parameters,
 289          * including channel number and call ID.
 290          */
 291         ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
 292         if (ret < 0)
 293                 goto error;
 294
 295         trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
 296                          here, NULL);
 297
 298         rxrpc_start_call_timer(call);
 299
 300         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
 301
 302         _leave(" = %p [new]", call);
 303         return call;
 304
 305         /* We unexpectedly found the user ID in the list after taking
 306          * the call_lock.  This shouldn't happen unless the user races
 307          * with itself and tries to add the same user ID twice at the
 308          * same time in different threads.
 309          */
 310 error_dup_user_ID:
 311         write_unlock(&rx->call_lock);
 312         release_sock(&rx->sk);
 313         ret = -EEXIST;
 314
 315 error:
 316         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 317                                     RX_CALL_DEAD, ret);
 318         trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
 319                          here, ERR_PTR(ret));
 320         rxrpc_release_call(rx, call);
 321         mutex_unlock(&call->user_mutex);
 322         rxrpc_put_call(call, rxrpc_call_put);
 323         _leave(" = %d", ret);
 324         return ERR_PTR(ret);
 325 }
 326
 327 /*
 328  * Set up an incoming call.  call->conn points to the connection.
 329  * This is called in BH context and isn't allowed to fail.
 330  */
 331 void rxrpc_incoming_call(struct rxrpc_sock *rx,
 332                          struct rxrpc_call *call,
 333                          struct sk_buff *skb)
 334 {
 335         struct rxrpc_connection *conn = call->conn;
 336         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 337         u32 chan;
 338
 339         _enter(",%d", call->conn->debug_id);
 340
 341         rcu_assign_pointer(call->socket, rx);
 342         call->call_id           = sp->hdr.callNumber;
 343         call->service_id        = sp->hdr.serviceId;
 344         call->cid               = sp->hdr.cid;
 345         call->state             = RXRPC_CALL_SERVER_ACCEPTING;
 346         if (sp->hdr.securityIndex > 0)
 347                 call->state     = RXRPC_CALL_SERVER_SECURING;
 348         call->cong_tstamp       = skb->tstamp;
 349
 350         /* Set the channel for this call.  We don't get channel_lock as we're
 351          * only defending against the data_ready handler (which we're called
 352          * from) and the RESPONSE packet parser (which is only really
 353          * interested in call_counter and can cope with a disagreement with the
 354          * call pointer).
 355          */
 356         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 357         conn->channels[chan].call_counter = call->call_id;
 358         conn->channels[chan].call_id = call->call_id;
 359         rcu_assign_pointer(conn->channels[chan].call, call);
 360
 361         spin_lock(&conn->params.peer->lock);
 362         hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets);
 363         spin_unlock(&conn->params.peer->lock);
 364
 365         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
 366
 367         rxrpc_start_call_timer(call);
 368         _leave("");
 369 }
 370
 371 /*
 372  * Queue a call's work processor, getting a ref to pass to the work queue.
 373  */
 374 bool rxrpc_queue_call(struct rxrpc_call *call)
 375 {
 376         const void *here = __builtin_return_address(0);
 377         int n = atomic_fetch_add_unless(&call->usage, 1, 0);
 378         if (n == 0)
 379                 return false;
 380         if (rxrpc_queue_work(&call->processor))
 381                 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
 382         else
 383                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 384         return true;
 385 }
 386
 387 /*
 388  * Queue a call's work processor, passing the callers ref to the work queue.
 389  */
 390 bool __rxrpc_queue_call(struct rxrpc_call *call)
 391 {
 392         const void *here = __builtin_return_address(0);
 393         int n = atomic_read(&call->usage);
 394         ASSERTCMP(n, >=, 1);
 395         if (rxrpc_queue_work(&call->processor))
 396                 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
 397         else
 398                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 399         return true;
 400 }
 401
 402 /*
 403  * Note the re-emergence of a call.
 404  */
 405 void rxrpc_see_call(struct rxrpc_call *call)
 406 {
 407         const void *here = __builtin_return_address(0);
 408         if (call) {
 409                 int n = atomic_read(&call->usage);
 410
 411                 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
 412         }
 413 }
 414
 415 /*
 416  * Note the addition of a ref on a call.
 417  */
 418 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 419 {
 420         const void *here = __builtin_return_address(0);
 421         int n = atomic_inc_return(&call->usage);
 422
 423         trace_rxrpc_call(call, op, n, here, NULL);
 424 }
 425
 426 /*
 427  * Detach a call from its owning socket.
 428  */
 429 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 430 {
 431         const void *here = __builtin_return_address(0);
 432         struct rxrpc_connection *conn = call->conn;
 433         bool put = false;
 434         int i;
 435
 436         _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
 437
 438         trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
 439                          here, (const void *)call->flags);
 440
 441         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 442
 443         spin_lock_bh(&call->lock);
 444         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 445                 BUG();
 446         spin_unlock_bh(&call->lock);
 447
 448         del_timer_sync(&call->timer);
 449
 450         /* Make sure we don't get any more notifications */
 451         write_lock_bh(&rx->recvmsg_lock);
 452
 453         if (!list_empty(&call->recvmsg_link)) {
 454                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 455                        call, call->events, call->flags);
 456                 list_del(&call->recvmsg_link);
 457                 put = true;
 458         }
 459
 460         /* list_empty() must return false in rxrpc_notify_socket() */
 461         call->recvmsg_link.next = NULL;
 462         call->recvmsg_link.prev = NULL;
 463
 464         write_unlock_bh(&rx->recvmsg_lock);
 465         if (put)
 466                 rxrpc_put_call(call, rxrpc_call_put);
 467
 468         write_lock(&rx->call_lock);
 469
 470         if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 471                 rb_erase(&call->sock_node, &rx->calls);
 472                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 473                 rxrpc_put_call(call, rxrpc_call_put_userid);
 474         }
 475
 476         list_del(&call->sock_link);
 477         write_unlock(&rx->call_lock);
 478
 479         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
 480
 481         if (conn)
 482                 rxrpc_disconnect_call(call);
 483
 484         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
 485                 rxrpc_free_skb(call->rxtx_buffer[i],
 486                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
 487                                 rxrpc_skb_rx_cleaned));
 488                 call->rxtx_buffer[i] = NULL;
 489         }
 490
 491         _leave("");
 492 }
 493
 494 /*
 495  * release all the calls associated with a socket
 496  */
 497 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 498 {
 499         struct rxrpc_call *call;
 500
 501         _enter("%p", rx);
 502
 503         while (!list_empty(&rx->to_be_accepted)) {
 504                 call = list_entry(rx->to_be_accepted.next,
 505                                   struct rxrpc_call, accept_link);
 506                 list_del(&call->accept_link);
 507                 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
 508                 rxrpc_put_call(call, rxrpc_call_put);
 509         }
 510
 511         while (!list_empty(&rx->sock_calls)) {
 512                 call = list_entry(rx->sock_calls.next,
 513                                   struct rxrpc_call, sock_link);
 514                 rxrpc_get_call(call, rxrpc_call_got);
 515                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
 516                 rxrpc_send_abort_packet(call);
 517                 rxrpc_release_call(rx, call);
 518                 rxrpc_put_call(call, rxrpc_call_put);
 519         }
 520
 521         _leave("");
 522 }
 523
 524 /*
 525  * release a call
 526  */
 527 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 528 {
 529         struct rxrpc_net *rxnet = call->rxnet;
 530         const void *here = __builtin_return_address(0);
 531         int n;
 532
 533         ASSERT(call != NULL);
 534
 535         n = atomic_dec_return(&call->usage);
 536         trace_rxrpc_call(call, op, n, here, NULL);
 537         ASSERTCMP(n, >=, 0);
 538         if (n == 0) {
 539                 _debug("call %d dead", call->debug_id);
 540                 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 541
 542                 if (!list_empty(&call->link)) {
 543                         write_lock(&rxnet->call_lock);
 544                         list_del_init(&call->link);
 545                         write_unlock(&rxnet->call_lock);
 546                 }
 547
 548                 rxrpc_cleanup_call(call);
 549         }
 550 }
 551
 552 /*
 553  * Final call destruction under RCU.
 554  */
 555 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
 556 {
 557         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 558         struct rxrpc_net *rxnet = call->rxnet;
 559
 560         rxrpc_put_peer(call->peer);
 561         kfree(call->rxtx_buffer);
 562         kfree(call->rxtx_annotations);
 563         kmem_cache_free(rxrpc_call_jar, call);
 564         if (atomic_dec_and_test(&rxnet->nr_calls))
 565                 wake_up_var(&rxnet->nr_calls);
 566 }
 567
 568 /*
 569  * clean up a call
 570  */
 571 void rxrpc_cleanup_call(struct rxrpc_call *call)
 572 {
 573         int i;
 574
 575         _net("DESTROY CALL %d", call->debug_id);
 576
 577         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 578
 579         del_timer_sync(&call->timer);
 580
 581         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 582         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 583         ASSERTCMP(call->conn, ==, NULL);
 584
 585         /* Clean up the Rx/Tx buffer */
 586         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
 587                 rxrpc_free_skb(call->rxtx_buffer[i],
 588                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
 589                                 rxrpc_skb_rx_cleaned));
 590
 591         rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned);
 592
 593         call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
 594 }
 595
 596 /*
 597  * Make sure that all calls are gone from a network namespace.  To reach this
 598  * point, any open UDP sockets in that namespace must have been closed, so any
 599  * outstanding calls cannot be doing I/O.
 600  */
 601 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
 602 {
 603         struct rxrpc_call *call;
 604
 605         _enter("");
 606
 607         if (list_empty(&rxnet->calls))
 608                 return;
 609
 610         write_lock(&rxnet->call_lock);
 611
 612         while (!list_empty(&rxnet->calls)) {
 613                 call = list_entry(rxnet->calls.next, struct rxrpc_call, link);
 614                 _debug("Zapping call %p", call);
 615
 616                 rxrpc_see_call(call);
 617                 list_del_init(&call->link);
 618
 619                 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
 620                        call, atomic_read(&call->usage),
 621                        rxrpc_call_states[call->state],
 622                        call->flags, call->events);
 623
 624                 write_unlock(&rxnet->call_lock);
 625                 cond_resched();
 626                 write_lock(&rxnet->call_lock);
 627         }
 628
 629         write_unlock(&rxnet->call_lock);
 630
 631         atomic_dec(&rxnet->nr_calls);
 632         wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
 633 }