net/rxrpc/call_object.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* RxRPC individual remote procedure call handling
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/slab.h>
  11 #include <linux/module.h>
  12 #include <linux/circ_buf.h>
  13 #include <linux/spinlock_types.h>
  14 #include <net/sock.h>
  15 #include <net/af_rxrpc.h>
  16 #include "ar-internal.h"
  17
  18 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
  19         [RXRPC_CALL_UNINITIALISED]              = "Uninit  ",
  20         [RXRPC_CALL_CLIENT_AWAIT_CONN]          = "ClWtConn",
  21         [RXRPC_CALL_CLIENT_SEND_REQUEST]        = "ClSndReq",
  22         [RXRPC_CALL_CLIENT_AWAIT_REPLY]         = "ClAwtRpl",
  23         [RXRPC_CALL_CLIENT_RECV_REPLY]          = "ClRcvRpl",
  24         [RXRPC_CALL_SERVER_PREALLOC]            = "SvPrealc",
  25         [RXRPC_CALL_SERVER_SECURING]            = "SvSecure",
  26         [RXRPC_CALL_SERVER_RECV_REQUEST]        = "SvRcvReq",
  27         [RXRPC_CALL_SERVER_ACK_REQUEST]         = "SvAckReq",
  28         [RXRPC_CALL_SERVER_SEND_REPLY]          = "SvSndRpl",
  29         [RXRPC_CALL_SERVER_AWAIT_ACK]           = "SvAwtACK",
  30         [RXRPC_CALL_COMPLETE]                   = "Complete",
  31 };
  32
  33 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
  34         [RXRPC_CALL_SUCCEEDED]                  = "Complete",
  35         [RXRPC_CALL_REMOTELY_ABORTED]           = "RmtAbort",
  36         [RXRPC_CALL_LOCALLY_ABORTED]            = "LocAbort",
  37         [RXRPC_CALL_LOCAL_ERROR]                = "LocError",
  38         [RXRPC_CALL_NETWORK_ERROR]              = "NetError",
  39 };
  40
  41 struct kmem_cache *rxrpc_call_jar;
  42
  43 static struct semaphore rxrpc_call_limiter =
  44         __SEMAPHORE_INITIALIZER(rxrpc_call_limiter, 1000);
  45 static struct semaphore rxrpc_kernel_call_limiter =
  46         __SEMAPHORE_INITIALIZER(rxrpc_kernel_call_limiter, 1000);
  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         call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
 161         atomic_inc(&rxnet->nr_calls);
 162         return call;
 163
 164 nomem_2:
 165         kfree(call->rxtx_buffer);
 166 nomem:
 167         kmem_cache_free(rxrpc_call_jar, call);
 168         return NULL;
 169 }
 170
 171 /*
 172  * Allocate a new client call.
 173  */
 174 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
 175                                                   struct sockaddr_rxrpc *srx,
 176                                                   gfp_t gfp,
 177                                                   unsigned int debug_id)
 178 {
 179         struct rxrpc_call *call;
 180         ktime_t now;
 181
 182         _enter("");
 183
 184         call = rxrpc_alloc_call(rx, gfp, debug_id);
 185         if (!call)
 186                 return ERR_PTR(-ENOMEM);
 187         call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
 188         call->service_id = srx->srx_service;
 189         call->tx_phase = true;
 190         now = ktime_get_real();
 191         call->acks_latest_ts = now;
 192         call->cong_tstamp = now;
 193
 194         _leave(" = %p", call);
 195         return call;
 196 }
 197
 198 /*
 199  * Initiate the call ack/resend/expiry timer.
 200  */
 201 static void rxrpc_start_call_timer(struct rxrpc_call *call)
 202 {
 203         unsigned long now = jiffies;
 204         unsigned long j = now + MAX_JIFFY_OFFSET;
 205
 206         call->ack_at = j;
 207         call->ack_lost_at = j;
 208         call->resend_at = j;
 209         call->ping_at = j;
 210         call->expect_rx_by = j;
 211         call->expect_req_by = j;
 212         call->expect_term_by = j;
 213         call->timer.expires = now;
 214 }
 215
 216 /*
 217  * Wait for a call slot to become available.
 218  */
 219 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
 220 {
 221         struct semaphore *limiter = &rxrpc_call_limiter;
 222
 223         if (p->kernel)
 224                 limiter = &rxrpc_kernel_call_limiter;
 225         if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
 226                 down(limiter);
 227                 return limiter;
 228         }
 229         return down_interruptible(limiter) < 0 ? NULL : limiter;
 230 }
 231
 232 /*
 233  * Release a call slot.
 234  */
 235 static void rxrpc_put_call_slot(struct rxrpc_call *call)
 236 {
 237         struct semaphore *limiter = &rxrpc_call_limiter;
 238
 239         if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
 240                 limiter = &rxrpc_kernel_call_limiter;
 241         up(limiter);
 242 }
 243
 244 /*
 245  * Set up a call for the given parameters.
 246  * - Called with the socket lock held, which it must release.
 247  * - If it returns a call, the call's lock will need releasing by the caller.
 248  */
 249 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 250                                          struct rxrpc_conn_parameters *cp,
 251                                          struct sockaddr_rxrpc *srx,
 252                                          struct rxrpc_call_params *p,
 253                                          gfp_t gfp,
 254                                          unsigned int debug_id)
 255         __releases(&rx->sk.sk_lock.slock)
 256         __acquires(&call->user_mutex)
 257 {
 258         struct rxrpc_call *call, *xcall;
 259         struct rxrpc_net *rxnet;
 260         struct semaphore *limiter;
 261         struct rb_node *parent, **pp;
 262         const void *here = __builtin_return_address(0);
 263         int ret;
 264
 265         _enter("%p,%lx", rx, p->user_call_ID);
 266
 267         limiter = rxrpc_get_call_slot(p, gfp);
 268         if (!limiter)
 269                 return ERR_PTR(-ERESTARTSYS);
 270
 271         call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
 272         if (IS_ERR(call)) {
 273                 release_sock(&rx->sk);
 274                 up(limiter);
 275                 _leave(" = %ld", PTR_ERR(call));
 276                 return call;
 277         }
 278
 279         call->interruptibility = p->interruptibility;
 280         call->tx_total_len = p->tx_total_len;
 281         trace_rxrpc_call(call->debug_id, rxrpc_call_new_client,
 282                          atomic_read(&call->usage),
 283                          here, (const void *)p->user_call_ID);
 284         if (p->kernel)
 285                 __set_bit(RXRPC_CALL_KERNEL, &call->flags);
 286
 287         /* We need to protect a partially set up call against the user as we
 288          * will be acting outside the socket lock.
 289          */
 290         mutex_lock(&call->user_mutex);
 291
 292         /* Publish the call, even though it is incompletely set up as yet */
 293         write_lock(&rx->call_lock);
 294
 295         pp = &rx->calls.rb_node;
 296         parent = NULL;
 297         while (*pp) {
 298                 parent = *pp;
 299                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 300
 301                 if (p->user_call_ID < xcall->user_call_ID)
 302                         pp = &(*pp)->rb_left;
 303                 else if (p->user_call_ID > xcall->user_call_ID)
 304                         pp = &(*pp)->rb_right;
 305                 else
 306                         goto error_dup_user_ID;
 307         }
 308
 309         rcu_assign_pointer(call->socket, rx);
 310         call->user_call_ID = p->user_call_ID;
 311         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 312         rxrpc_get_call(call, rxrpc_call_got_userid);
 313         rb_link_node(&call->sock_node, parent, pp);
 314         rb_insert_color(&call->sock_node, &rx->calls);
 315         list_add(&call->sock_link, &rx->sock_calls);
 316
 317         write_unlock(&rx->call_lock);
 318
 319         rxnet = call->rxnet;
 320         write_lock(&rxnet->call_lock);
 321         list_add_tail(&call->link, &rxnet->calls);
 322         write_unlock(&rxnet->call_lock);
 323
 324         /* From this point on, the call is protected by its own lock. */
 325         release_sock(&rx->sk);
 326
 327         /* Set up or get a connection record and set the protocol parameters,
 328          * including channel number and call ID.
 329          */
 330         ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
 331         if (ret < 0)
 332                 goto error_attached_to_socket;
 333
 334         trace_rxrpc_call(call->debug_id, rxrpc_call_connected,
 335                          atomic_read(&call->usage), here, NULL);
 336
 337         rxrpc_start_call_timer(call);
 338
 339         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
 340
 341         _leave(" = %p [new]", call);
 342         return call;
 343
 344         /* We unexpectedly found the user ID in the list after taking
 345          * the call_lock.  This shouldn't happen unless the user races
 346          * with itself and tries to add the same user ID twice at the
 347          * same time in different threads.
 348          */
 349 error_dup_user_ID:
 350         write_unlock(&rx->call_lock);
 351         release_sock(&rx->sk);
 352         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 353                                     RX_CALL_DEAD, -EEXIST);
 354         trace_rxrpc_call(call->debug_id, rxrpc_call_error,
 355                          atomic_read(&call->usage), here, ERR_PTR(-EEXIST));
 356         rxrpc_release_call(rx, call);
 357         mutex_unlock(&call->user_mutex);
 358         rxrpc_put_call(call, rxrpc_call_put);
 359         _leave(" = -EEXIST");
 360         return ERR_PTR(-EEXIST);
 361
 362         /* We got an error, but the call is attached to the socket and is in
 363          * need of release.  However, we might now race with recvmsg() when
 364          * completing the call queues it.  Return 0 from sys_sendmsg() and
 365          * leave the error to recvmsg() to deal with.
 366          */
 367 error_attached_to_socket:
 368         trace_rxrpc_call(call->debug_id, rxrpc_call_error,
 369                          atomic_read(&call->usage), here, ERR_PTR(ret));
 370         set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
 371         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 372                                     RX_CALL_DEAD, ret);
 373         _leave(" = c=%08x [err]", call->debug_id);
 374         return call;
 375 }
 376
 377 /*
 378  * Set up an incoming call.  call->conn points to the connection.
 379  * This is called in BH context and isn't allowed to fail.
 380  */
 381 void rxrpc_incoming_call(struct rxrpc_sock *rx,
 382                          struct rxrpc_call *call,
 383                          struct sk_buff *skb)
 384 {
 385         struct rxrpc_connection *conn = call->conn;
 386         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 387         u32 chan;
 388
 389         _enter(",%d", call->conn->debug_id);
 390
 391         rcu_assign_pointer(call->socket, rx);
 392         call->call_id           = sp->hdr.callNumber;
 393         call->service_id        = sp->hdr.serviceId;
 394         call->cid               = sp->hdr.cid;
 395         call->state             = RXRPC_CALL_SERVER_SECURING;
 396         call->cong_tstamp       = skb->tstamp;
 397
 398         /* Set the channel for this call.  We don't get channel_lock as we're
 399          * only defending against the data_ready handler (which we're called
 400          * from) and the RESPONSE packet parser (which is only really
 401          * interested in call_counter and can cope with a disagreement with the
 402          * call pointer).
 403          */
 404         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 405         conn->channels[chan].call_counter = call->call_id;
 406         conn->channels[chan].call_id = call->call_id;
 407         rcu_assign_pointer(conn->channels[chan].call, call);
 408
 409         spin_lock(&conn->params.peer->lock);
 410         hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets);
 411         spin_unlock(&conn->params.peer->lock);
 412
 413         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
 414
 415         rxrpc_start_call_timer(call);
 416         _leave("");
 417 }
 418
 419 /*
 420  * Queue a call's work processor, getting a ref to pass to the work queue.
 421  */
 422 bool rxrpc_queue_call(struct rxrpc_call *call)
 423 {
 424         const void *here = __builtin_return_address(0);
 425         int n = atomic_fetch_add_unless(&call->usage, 1, 0);
 426         if (n == 0)
 427                 return false;
 428         if (rxrpc_queue_work(&call->processor))
 429                 trace_rxrpc_call(call->debug_id, rxrpc_call_queued, n + 1,
 430                                  here, NULL);
 431         else
 432                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 433         return true;
 434 }
 435
 436 /*
 437  * Queue a call's work processor, passing the callers ref to the work queue.
 438  */
 439 bool __rxrpc_queue_call(struct rxrpc_call *call)
 440 {
 441         const void *here = __builtin_return_address(0);
 442         int n = atomic_read(&call->usage);
 443         ASSERTCMP(n, >=, 1);
 444         if (rxrpc_queue_work(&call->processor))
 445                 trace_rxrpc_call(call->debug_id, rxrpc_call_queued_ref, n,
 446                                  here, NULL);
 447         else
 448                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 449         return true;
 450 }
 451
 452 /*
 453  * Note the re-emergence of a call.
 454  */
 455 void rxrpc_see_call(struct rxrpc_call *call)
 456 {
 457         const void *here = __builtin_return_address(0);
 458         if (call) {
 459                 int n = atomic_read(&call->usage);
 460
 461                 trace_rxrpc_call(call->debug_id, rxrpc_call_seen, n,
 462                                  here, NULL);
 463         }
 464 }
 465
 466 /*
 467  * Note the addition of a ref on a call.
 468  */
 469 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 470 {
 471         const void *here = __builtin_return_address(0);
 472         int n = atomic_inc_return(&call->usage);
 473
 474         trace_rxrpc_call(call->debug_id, op, n, here, NULL);
 475 }
 476
 477 /*
 478  * Clean up the RxTx skb ring.
 479  */
 480 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
 481 {
 482         int i;
 483
 484         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
 485                 rxrpc_free_skb(call->rxtx_buffer[i], rxrpc_skb_cleaned);
 486                 call->rxtx_buffer[i] = NULL;
 487         }
 488 }
 489
 490 /*
 491  * Detach a call from its owning socket.
 492  */
 493 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 494 {
 495         const void *here = __builtin_return_address(0);
 496         struct rxrpc_connection *conn = call->conn;
 497         bool put = false;
 498
 499         _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
 500
 501         trace_rxrpc_call(call->debug_id, rxrpc_call_release,
 502                          atomic_read(&call->usage),
 503                          here, (const void *)call->flags);
 504
 505         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 506
 507         spin_lock_bh(&call->lock);
 508         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 509                 BUG();
 510         spin_unlock_bh(&call->lock);
 511
 512         rxrpc_put_call_slot(call);
 513
 514         del_timer_sync(&call->timer);
 515
 516         /* Make sure we don't get any more notifications */
 517         write_lock_bh(&rx->recvmsg_lock);
 518
 519         if (!list_empty(&call->recvmsg_link)) {
 520                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 521                        call, call->events, call->flags);
 522                 list_del(&call->recvmsg_link);
 523                 put = true;
 524         }
 525
 526         /* list_empty() must return false in rxrpc_notify_socket() */
 527         call->recvmsg_link.next = NULL;
 528         call->recvmsg_link.prev = NULL;
 529
 530         write_unlock_bh(&rx->recvmsg_lock);
 531         if (put)
 532                 rxrpc_put_call(call, rxrpc_call_put);
 533
 534         write_lock(&rx->call_lock);
 535
 536         if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 537                 rb_erase(&call->sock_node, &rx->calls);
 538                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 539                 rxrpc_put_call(call, rxrpc_call_put_userid);
 540         }
 541
 542         list_del(&call->sock_link);
 543         write_unlock(&rx->call_lock);
 544
 545         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
 546
 547         if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
 548                 rxrpc_disconnect_call(call);
 549         if (call->security)
 550                 call->security->free_call_crypto(call);
 551
 552         rxrpc_cleanup_ring(call);
 553         _leave("");
 554 }
 555
 556 /*
 557  * release all the calls associated with a socket
 558  */
 559 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 560 {
 561         struct rxrpc_call *call;
 562
 563         _enter("%p", rx);
 564
 565         while (!list_empty(&rx->to_be_accepted)) {
 566                 call = list_entry(rx->to_be_accepted.next,
 567                                   struct rxrpc_call, accept_link);
 568                 list_del(&call->accept_link);
 569                 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
 570                 rxrpc_put_call(call, rxrpc_call_put);
 571         }
 572
 573         while (!list_empty(&rx->sock_calls)) {
 574                 call = list_entry(rx->sock_calls.next,
 575                                   struct rxrpc_call, sock_link);
 576                 rxrpc_get_call(call, rxrpc_call_got);
 577                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
 578                 rxrpc_send_abort_packet(call);
 579                 rxrpc_release_call(rx, call);
 580                 rxrpc_put_call(call, rxrpc_call_put);
 581         }
 582
 583         _leave("");
 584 }
 585
 586 /*
 587  * release a call
 588  */
 589 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 590 {
 591         struct rxrpc_net *rxnet = call->rxnet;
 592         const void *here = __builtin_return_address(0);
 593         unsigned int debug_id = call->debug_id;
 594         int n;
 595
 596         ASSERT(call != NULL);
 597
 598         n = atomic_dec_return(&call->usage);
 599         trace_rxrpc_call(debug_id, op, n, here, NULL);
 600         ASSERTCMP(n, >=, 0);
 601         if (n == 0) {
 602                 _debug("call %d dead", call->debug_id);
 603                 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 604
 605                 if (!list_empty(&call->link)) {
 606                         write_lock(&rxnet->call_lock);
 607                         list_del_init(&call->link);
 608                         write_unlock(&rxnet->call_lock);
 609                 }
 610
 611                 rxrpc_cleanup_call(call);
 612         }
 613 }
 614
 615 /*
 616  * Final call destruction - but must be done in process context.
 617  */
 618 static void rxrpc_destroy_call(struct work_struct *work)
 619 {
 620         struct rxrpc_call *call = container_of(work, struct rxrpc_call, processor);
 621         struct rxrpc_net *rxnet = call->rxnet;
 622
 623         rxrpc_put_connection(call->conn);
 624         rxrpc_put_peer(call->peer);
 625         kfree(call->rxtx_buffer);
 626         kfree(call->rxtx_annotations);
 627         kmem_cache_free(rxrpc_call_jar, call);
 628         if (atomic_dec_and_test(&rxnet->nr_calls))
 629                 wake_up_var(&rxnet->nr_calls);
 630 }
 631
 632 /*
 633  * Final call destruction under RCU.
 634  */
 635 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
 636 {
 637         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 638
 639         if (in_softirq()) {
 640                 INIT_WORK(&call->processor, rxrpc_destroy_call);
 641                 if (!rxrpc_queue_work(&call->processor))
 642                         BUG();
 643         } else {
 644                 rxrpc_destroy_call(&call->processor);
 645         }
 646 }
 647
 648 /*
 649  * clean up a call
 650  */
 651 void rxrpc_cleanup_call(struct rxrpc_call *call)
 652 {
 653         _net("DESTROY CALL %d", call->debug_id);
 654
 655         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 656
 657         del_timer_sync(&call->timer);
 658
 659         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 660         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 661
 662         rxrpc_cleanup_ring(call);
 663         rxrpc_free_skb(call->tx_pending, rxrpc_skb_cleaned);
 664
 665         call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
 666 }
 667
 668 /*
 669  * Make sure that all calls are gone from a network namespace.  To reach this
 670  * point, any open UDP sockets in that namespace must have been closed, so any
 671  * outstanding calls cannot be doing I/O.
 672  */
 673 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
 674 {
 675         struct rxrpc_call *call;
 676
 677         _enter("");
 678
 679         if (!list_empty(&rxnet->calls)) {
 680                 write_lock(&rxnet->call_lock);
 681
 682                 while (!list_empty(&rxnet->calls)) {
 683                         call = list_entry(rxnet->calls.next,
 684                                           struct rxrpc_call, link);
 685                         _debug("Zapping call %p", call);
 686
 687                         rxrpc_see_call(call);
 688                         list_del_init(&call->link);
 689
 690                         pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
 691                                call, atomic_read(&call->usage),
 692                                rxrpc_call_states[call->state],
 693                                call->flags, call->events);
 694
 695                         write_unlock(&rxnet->call_lock);
 696                         cond_resched();
 697                         write_lock(&rxnet->call_lock);
 698                 }
 699
 700                 write_unlock(&rxnet->call_lock);
 701         }
 702
 703         atomic_dec(&rxnet->nr_calls);
 704         wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
 705 }