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_expired(call, jiffies);
  56                 __rxrpc_queue_call(call);
  57         } else {
  58                 rxrpc_put_call(call, rxrpc_call_put);
  59         }
  60 }
  61
  62 void rxrpc_reduce_call_timer(struct rxrpc_call *call,
  63                              unsigned long expire_at,
  64                              unsigned long now,
  65                              enum rxrpc_timer_trace why)
  66 {
  67         if (rxrpc_try_get_call(call, rxrpc_call_got_timer)) {
  68                 trace_rxrpc_timer(call, why, now);
  69                 if (timer_reduce(&call->timer, expire_at))
  70                         rxrpc_put_call(call, rxrpc_call_put_notimer);
  71         }
  72 }
  73
  74 void rxrpc_delete_call_timer(struct rxrpc_call *call)
  75 {
  76         if (del_timer_sync(&call->timer))
  77                 rxrpc_put_call(call, rxrpc_call_put_timer);
  78 }
  79
  80 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
  81
  82 /*
  83  * find an extant server call
  84  * - called in process context with IRQs enabled
  85  */
  86 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
  87                                               unsigned long user_call_ID)
  88 {
  89         struct rxrpc_call *call;
  90         struct rb_node *p;
  91
  92         _enter("%p,%lx", rx, user_call_ID);
  93
  94         read_lock(&rx->call_lock);
  95
  96         p = rx->calls.rb_node;
  97         while (p) {
  98                 call = rb_entry(p, struct rxrpc_call, sock_node);
  99
 100                 if (user_call_ID < call->user_call_ID)
 101                         p = p->rb_left;
 102                 else if (user_call_ID > call->user_call_ID)
 103                         p = p->rb_right;
 104                 else
 105                         goto found_extant_call;
 106         }
 107
 108         read_unlock(&rx->call_lock);
 109         _leave(" = NULL");
 110         return NULL;
 111
 112 found_extant_call:
 113         rxrpc_get_call(call, rxrpc_call_got);
 114         read_unlock(&rx->call_lock);
 115         _leave(" = %p [%d]", call, refcount_read(&call->ref));
 116         return call;
 117 }
 118
 119 /*
 120  * allocate a new call
 121  */
 122 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
 123                                     unsigned int debug_id)
 124 {
 125         struct rxrpc_call *call;
 126         struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
 127
 128         call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
 129         if (!call)
 130                 return NULL;
 131
 132         mutex_init(&call->user_mutex);
 133
 134         /* Prevent lockdep reporting a deadlock false positive between the afs
 135          * filesystem and sys_sendmsg() via the mmap sem.
 136          */
 137         if (rx->sk.sk_kern_sock)
 138                 lockdep_set_class(&call->user_mutex,
 139                                   &rxrpc_call_user_mutex_lock_class_key);
 140
 141         timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
 142         INIT_WORK(&call->processor, &rxrpc_process_call);
 143         INIT_LIST_HEAD(&call->link);
 144         INIT_LIST_HEAD(&call->chan_wait_link);
 145         INIT_LIST_HEAD(&call->accept_link);
 146         INIT_LIST_HEAD(&call->recvmsg_link);
 147         INIT_LIST_HEAD(&call->sock_link);
 148         INIT_LIST_HEAD(&call->tx_buffer);
 149         skb_queue_head_init(&call->recvmsg_queue);
 150         skb_queue_head_init(&call->rx_oos_queue);
 151         init_waitqueue_head(&call->waitq);
 152         spin_lock_init(&call->notify_lock);
 153         spin_lock_init(&call->tx_lock);
 154         spin_lock_init(&call->input_lock);
 155         spin_lock_init(&call->acks_ack_lock);
 156         rwlock_init(&call->state_lock);
 157         refcount_set(&call->ref, 1);
 158         call->debug_id = debug_id;
 159         call->tx_total_len = -1;
 160         call->next_rx_timo = 20 * HZ;
 161         call->next_req_timo = 1 * HZ;
 162         atomic64_set(&call->ackr_window, 0x100000001ULL);
 163
 164         memset(&call->sock_node, 0xed, sizeof(call->sock_node));
 165
 166         call->rx_winsize = rxrpc_rx_window_size;
 167         call->tx_winsize = 16;
 168
 169         if (RXRPC_TX_SMSS > 2190)
 170                 call->cong_cwnd = 2;
 171         else if (RXRPC_TX_SMSS > 1095)
 172                 call->cong_cwnd = 3;
 173         else
 174                 call->cong_cwnd = 4;
 175         call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
 176
 177         call->rxnet = rxnet;
 178         call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
 179         atomic_inc(&rxnet->nr_calls);
 180         return call;
 181 }
 182
 183 /*
 184  * Allocate a new client call.
 185  */
 186 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
 187                                                   struct sockaddr_rxrpc *srx,
 188                                                   gfp_t gfp,
 189                                                   unsigned int debug_id)
 190 {
 191         struct rxrpc_call *call;
 192         ktime_t now;
 193
 194         _enter("");
 195
 196         call = rxrpc_alloc_call(rx, gfp, debug_id);
 197         if (!call)
 198                 return ERR_PTR(-ENOMEM);
 199         call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
 200         call->service_id = srx->srx_service;
 201         now = ktime_get_real();
 202         call->acks_latest_ts = now;
 203         call->cong_tstamp = now;
 204
 205         _leave(" = %p", call);
 206         return call;
 207 }
 208
 209 /*
 210  * Initiate the call ack/resend/expiry timer.
 211  */
 212 static void rxrpc_start_call_timer(struct rxrpc_call *call)
 213 {
 214         unsigned long now = jiffies;
 215         unsigned long j = now + MAX_JIFFY_OFFSET;
 216
 217         call->delay_ack_at = j;
 218         call->ack_lost_at = j;
 219         call->resend_at = j;
 220         call->ping_at = j;
 221         call->expect_rx_by = j;
 222         call->expect_req_by = j;
 223         call->expect_term_by = j;
 224         call->timer.expires = now;
 225 }
 226
 227 /*
 228  * Wait for a call slot to become available.
 229  */
 230 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
 231 {
 232         struct semaphore *limiter = &rxrpc_call_limiter;
 233
 234         if (p->kernel)
 235                 limiter = &rxrpc_kernel_call_limiter;
 236         if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
 237                 down(limiter);
 238                 return limiter;
 239         }
 240         return down_interruptible(limiter) < 0 ? NULL : limiter;
 241 }
 242
 243 /*
 244  * Release a call slot.
 245  */
 246 static void rxrpc_put_call_slot(struct rxrpc_call *call)
 247 {
 248         struct semaphore *limiter = &rxrpc_call_limiter;
 249
 250         if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
 251                 limiter = &rxrpc_kernel_call_limiter;
 252         up(limiter);
 253 }
 254
 255 /*
 256  * Set up a call for the given parameters.
 257  * - Called with the socket lock held, which it must release.
 258  * - If it returns a call, the call's lock will need releasing by the caller.
 259  */
 260 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 261                                          struct rxrpc_conn_parameters *cp,
 262                                          struct sockaddr_rxrpc *srx,
 263                                          struct rxrpc_call_params *p,
 264                                          gfp_t gfp,
 265                                          unsigned int debug_id)
 266         __releases(&rx->sk.sk_lock.slock)
 267         __acquires(&call->user_mutex)
 268 {
 269         struct rxrpc_call *call, *xcall;
 270         struct rxrpc_net *rxnet;
 271         struct semaphore *limiter;
 272         struct rb_node *parent, **pp;
 273         const void *here = __builtin_return_address(0);
 274         int ret;
 275
 276         _enter("%p,%lx", rx, p->user_call_ID);
 277
 278         limiter = rxrpc_get_call_slot(p, gfp);
 279         if (!limiter) {
 280                 release_sock(&rx->sk);
 281                 return ERR_PTR(-ERESTARTSYS);
 282         }
 283
 284         call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
 285         if (IS_ERR(call)) {
 286                 release_sock(&rx->sk);
 287                 up(limiter);
 288                 _leave(" = %ld", PTR_ERR(call));
 289                 return call;
 290         }
 291
 292         call->interruptibility = p->interruptibility;
 293         call->tx_total_len = p->tx_total_len;
 294         trace_rxrpc_call(call->debug_id, rxrpc_call_new_client,
 295                          refcount_read(&call->ref),
 296                          here, (const void *)p->user_call_ID);
 297         if (p->kernel)
 298                 __set_bit(RXRPC_CALL_KERNEL, &call->flags);
 299
 300         /* We need to protect a partially set up call against the user as we
 301          * will be acting outside the socket lock.
 302          */
 303         mutex_lock(&call->user_mutex);
 304
 305         /* Publish the call, even though it is incompletely set up as yet */
 306         write_lock(&rx->call_lock);
 307
 308         pp = &rx->calls.rb_node;
 309         parent = NULL;
 310         while (*pp) {
 311                 parent = *pp;
 312                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 313
 314                 if (p->user_call_ID < xcall->user_call_ID)
 315                         pp = &(*pp)->rb_left;
 316                 else if (p->user_call_ID > xcall->user_call_ID)
 317                         pp = &(*pp)->rb_right;
 318                 else
 319                         goto error_dup_user_ID;
 320         }
 321
 322         rcu_assign_pointer(call->socket, rx);
 323         call->user_call_ID = p->user_call_ID;
 324         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 325         rxrpc_get_call(call, rxrpc_call_got_userid);
 326         rb_link_node(&call->sock_node, parent, pp);
 327         rb_insert_color(&call->sock_node, &rx->calls);
 328         list_add(&call->sock_link, &rx->sock_calls);
 329
 330         write_unlock(&rx->call_lock);
 331
 332         rxnet = call->rxnet;
 333         spin_lock_bh(&rxnet->call_lock);
 334         list_add_tail_rcu(&call->link, &rxnet->calls);
 335         spin_unlock_bh(&rxnet->call_lock);
 336
 337         /* From this point on, the call is protected by its own lock. */
 338         release_sock(&rx->sk);
 339
 340         /* Set up or get a connection record and set the protocol parameters,
 341          * including channel number and call ID.
 342          */
 343         ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
 344         if (ret < 0)
 345                 goto error_attached_to_socket;
 346
 347         trace_rxrpc_call(call->debug_id, rxrpc_call_connected,
 348                          refcount_read(&call->ref), here, NULL);
 349
 350         rxrpc_start_call_timer(call);
 351
 352         _leave(" = %p [new]", call);
 353         return call;
 354
 355         /* We unexpectedly found the user ID in the list after taking
 356          * the call_lock.  This shouldn't happen unless the user races
 357          * with itself and tries to add the same user ID twice at the
 358          * same time in different threads.
 359          */
 360 error_dup_user_ID:
 361         write_unlock(&rx->call_lock);
 362         release_sock(&rx->sk);
 363         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 364                                     RX_CALL_DEAD, -EEXIST);
 365         trace_rxrpc_call(call->debug_id, rxrpc_call_error,
 366                          refcount_read(&call->ref), here, ERR_PTR(-EEXIST));
 367         rxrpc_release_call(rx, call);
 368         mutex_unlock(&call->user_mutex);
 369         rxrpc_put_call(call, rxrpc_call_put);
 370         _leave(" = -EEXIST");
 371         return ERR_PTR(-EEXIST);
 372
 373         /* We got an error, but the call is attached to the socket and is in
 374          * need of release.  However, we might now race with recvmsg() when
 375          * completing the call queues it.  Return 0 from sys_sendmsg() and
 376          * leave the error to recvmsg() to deal with.
 377          */
 378 error_attached_to_socket:
 379         trace_rxrpc_call(call->debug_id, rxrpc_call_error,
 380                          refcount_read(&call->ref), here, ERR_PTR(ret));
 381         set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
 382         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 383                                     RX_CALL_DEAD, ret);
 384         _leave(" = c=%08x [err]", call->debug_id);
 385         return call;
 386 }
 387
 388 /*
 389  * Set up an incoming call.  call->conn points to the connection.
 390  * This is called in BH context and isn't allowed to fail.
 391  */
 392 void rxrpc_incoming_call(struct rxrpc_sock *rx,
 393                          struct rxrpc_call *call,
 394                          struct sk_buff *skb)
 395 {
 396         struct rxrpc_connection *conn = call->conn;
 397         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 398         u32 chan;
 399
 400         _enter(",%d", call->conn->debug_id);
 401
 402         rcu_assign_pointer(call->socket, rx);
 403         call->call_id           = sp->hdr.callNumber;
 404         call->service_id        = sp->hdr.serviceId;
 405         call->cid               = sp->hdr.cid;
 406         call->state             = RXRPC_CALL_SERVER_SECURING;
 407         call->cong_tstamp       = skb->tstamp;
 408
 409         /* Set the channel for this call.  We don't get channel_lock as we're
 410          * only defending against the data_ready handler (which we're called
 411          * from) and the RESPONSE packet parser (which is only really
 412          * interested in call_counter and can cope with a disagreement with the
 413          * call pointer).
 414          */
 415         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 416         conn->channels[chan].call_counter = call->call_id;
 417         conn->channels[chan].call_id = call->call_id;
 418         rcu_assign_pointer(conn->channels[chan].call, call);
 419
 420         spin_lock(&conn->params.peer->lock);
 421         hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets);
 422         spin_unlock(&conn->params.peer->lock);
 423
 424         rxrpc_start_call_timer(call);
 425         _leave("");
 426 }
 427
 428 /*
 429  * Queue a call's work processor, getting a ref to pass to the work queue.
 430  */
 431 bool rxrpc_queue_call(struct rxrpc_call *call)
 432 {
 433         const void *here = __builtin_return_address(0);
 434         int n;
 435
 436         if (!__refcount_inc_not_zero(&call->ref, &n))
 437                 return false;
 438         if (rxrpc_queue_work(&call->processor))
 439                 trace_rxrpc_call(call->debug_id, rxrpc_call_queued, n + 1,
 440                                  here, NULL);
 441         else
 442                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 443         return true;
 444 }
 445
 446 /*
 447  * Queue a call's work processor, passing the callers ref to the work queue.
 448  */
 449 bool __rxrpc_queue_call(struct rxrpc_call *call)
 450 {
 451         const void *here = __builtin_return_address(0);
 452         int n = refcount_read(&call->ref);
 453         ASSERTCMP(n, >=, 1);
 454         if (rxrpc_queue_work(&call->processor))
 455                 trace_rxrpc_call(call->debug_id, rxrpc_call_queued_ref, n,
 456                                  here, NULL);
 457         else
 458                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 459         return true;
 460 }
 461
 462 /*
 463  * Note the re-emergence of a call.
 464  */
 465 void rxrpc_see_call(struct rxrpc_call *call)
 466 {
 467         const void *here = __builtin_return_address(0);
 468         if (call) {
 469                 int n = refcount_read(&call->ref);
 470
 471                 trace_rxrpc_call(call->debug_id, rxrpc_call_seen, n,
 472                                  here, NULL);
 473         }
 474 }
 475
 476 bool rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 477 {
 478         const void *here = __builtin_return_address(0);
 479         int n;
 480
 481         if (!__refcount_inc_not_zero(&call->ref, &n))
 482                 return false;
 483         trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
 484         return true;
 485 }
 486
 487 /*
 488  * Note the addition of a ref on a call.
 489  */
 490 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 491 {
 492         const void *here = __builtin_return_address(0);
 493         int n;
 494
 495         __refcount_inc(&call->ref, &n);
 496         trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
 497 }
 498
 499 /*
 500  * Clean up the Rx skb ring.
 501  */
 502 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
 503 {
 504         skb_queue_purge(&call->recvmsg_queue);
 505         skb_queue_purge(&call->rx_oos_queue);
 506 }
 507
 508 /*
 509  * Detach a call from its owning socket.
 510  */
 511 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 512 {
 513         const void *here = __builtin_return_address(0);
 514         struct rxrpc_connection *conn = call->conn;
 515         bool put = false;
 516
 517         _enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
 518
 519         trace_rxrpc_call(call->debug_id, rxrpc_call_release,
 520                          refcount_read(&call->ref),
 521                          here, (const void *)call->flags);
 522
 523         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 524
 525         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 526                 BUG();
 527
 528         rxrpc_put_call_slot(call);
 529         rxrpc_delete_call_timer(call);
 530
 531         /* Make sure we don't get any more notifications */
 532         write_lock_bh(&rx->recvmsg_lock);
 533
 534         if (!list_empty(&call->recvmsg_link)) {
 535                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 536                        call, call->events, call->flags);
 537                 list_del(&call->recvmsg_link);
 538                 put = true;
 539         }
 540
 541         /* list_empty() must return false in rxrpc_notify_socket() */
 542         call->recvmsg_link.next = NULL;
 543         call->recvmsg_link.prev = NULL;
 544
 545         write_unlock_bh(&rx->recvmsg_lock);
 546         if (put)
 547                 rxrpc_put_call(call, rxrpc_call_put);
 548
 549         write_lock(&rx->call_lock);
 550
 551         if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 552                 rb_erase(&call->sock_node, &rx->calls);
 553                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 554                 rxrpc_put_call(call, rxrpc_call_put_userid);
 555         }
 556
 557         list_del(&call->sock_link);
 558         write_unlock(&rx->call_lock);
 559
 560         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
 561
 562         if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
 563                 rxrpc_disconnect_call(call);
 564         if (call->security)
 565                 call->security->free_call_crypto(call);
 566         _leave("");
 567 }
 568
 569 /*
 570  * release all the calls associated with a socket
 571  */
 572 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 573 {
 574         struct rxrpc_call *call;
 575
 576         _enter("%p", rx);
 577
 578         while (!list_empty(&rx->to_be_accepted)) {
 579                 call = list_entry(rx->to_be_accepted.next,
 580                                   struct rxrpc_call, accept_link);
 581                 list_del(&call->accept_link);
 582                 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
 583                 rxrpc_put_call(call, rxrpc_call_put);
 584         }
 585
 586         while (!list_empty(&rx->sock_calls)) {
 587                 call = list_entry(rx->sock_calls.next,
 588                                   struct rxrpc_call, sock_link);
 589                 rxrpc_get_call(call, rxrpc_call_got);
 590                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
 591                 rxrpc_send_abort_packet(call);
 592                 rxrpc_release_call(rx, call);
 593                 rxrpc_put_call(call, rxrpc_call_put);
 594         }
 595
 596         _leave("");
 597 }
 598
 599 /*
 600  * release a call
 601  */
 602 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 603 {
 604         struct rxrpc_net *rxnet = call->rxnet;
 605         const void *here = __builtin_return_address(0);
 606         unsigned int debug_id = call->debug_id;
 607         bool dead;
 608         int n;
 609
 610         ASSERT(call != NULL);
 611
 612         dead = __refcount_dec_and_test(&call->ref, &n);
 613         trace_rxrpc_call(debug_id, op, n, here, NULL);
 614         if (dead) {
 615                 _debug("call %d dead", call->debug_id);
 616                 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 617
 618                 if (!list_empty(&call->link)) {
 619                         spin_lock_bh(&rxnet->call_lock);
 620                         list_del_init(&call->link);
 621                         spin_unlock_bh(&rxnet->call_lock);
 622                 }
 623
 624                 rxrpc_cleanup_call(call);
 625         }
 626 }
 627
 628 /*
 629  * Final call destruction - but must be done in process context.
 630  */
 631 static void rxrpc_destroy_call(struct work_struct *work)
 632 {
 633         struct rxrpc_call *call = container_of(work, struct rxrpc_call, processor);
 634         struct rxrpc_net *rxnet = call->rxnet;
 635
 636         rxrpc_delete_call_timer(call);
 637
 638         rxrpc_put_connection(call->conn);
 639         rxrpc_put_peer(call->peer);
 640         kmem_cache_free(rxrpc_call_jar, call);
 641         if (atomic_dec_and_test(&rxnet->nr_calls))
 642                 wake_up_var(&rxnet->nr_calls);
 643 }
 644
 645 /*
 646  * Final call destruction under RCU.
 647  */
 648 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
 649 {
 650         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 651
 652         if (in_softirq()) {
 653                 INIT_WORK(&call->processor, rxrpc_destroy_call);
 654                 if (!rxrpc_queue_work(&call->processor))
 655                         BUG();
 656         } else {
 657                 rxrpc_destroy_call(&call->processor);
 658         }
 659 }
 660
 661 /*
 662  * clean up a call
 663  */
 664 void rxrpc_cleanup_call(struct rxrpc_call *call)
 665 {
 666         struct rxrpc_txbuf *txb;
 667
 668         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 669
 670         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 671         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 672
 673         rxrpc_cleanup_ring(call);
 674         while ((txb = list_first_entry_or_null(&call->tx_buffer,
 675                                                struct rxrpc_txbuf, call_link))) {
 676                 list_del(&txb->call_link);
 677                 rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
 678         }
 679         rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
 680         rxrpc_free_skb(call->acks_soft_tbl, rxrpc_skb_cleaned);
 681
 682         call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
 683 }
 684
 685 /*
 686  * Make sure that all calls are gone from a network namespace.  To reach this
 687  * point, any open UDP sockets in that namespace must have been closed, so any
 688  * outstanding calls cannot be doing I/O.
 689  */
 690 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
 691 {
 692         struct rxrpc_call *call;
 693
 694         _enter("");
 695
 696         if (!list_empty(&rxnet->calls)) {
 697                 spin_lock_bh(&rxnet->call_lock);
 698
 699                 while (!list_empty(&rxnet->calls)) {
 700                         call = list_entry(rxnet->calls.next,
 701                                           struct rxrpc_call, link);
 702                         _debug("Zapping call %p", call);
 703
 704                         rxrpc_see_call(call);
 705                         list_del_init(&call->link);
 706
 707                         pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
 708                                call, refcount_read(&call->ref),
 709                                rxrpc_call_states[call->state],
 710                                call->flags, call->events);
 711
 712                         spin_unlock_bh(&rxnet->call_lock);
 713                         cond_resched();
 714                         spin_lock_bh(&rxnet->call_lock);
 715                 }
 716
 717                 spin_unlock_bh(&rxnet->call_lock);
 718         }
 719
 720         atomic_dec(&rxnet->nr_calls);
 721         wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
 722 }