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 void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what)
  49 {
  50         struct rxrpc_local *local;
  51         struct rxrpc_peer *peer = call->peer;
  52         bool busy;
  53
  54         if (WARN_ON_ONCE(!peer))
  55                 return;
  56         local = peer->local;
  57
  58         if (call->state < RXRPC_CALL_COMPLETE) {
  59                 spin_lock_bh(&local->lock);
  60                 busy = !list_empty(&call->attend_link);
  61                 trace_rxrpc_poke_call(call, busy, what);
  62                 if (!busy) {
  63                         rxrpc_get_call(call, rxrpc_call_get_poke);
  64                         list_add_tail(&call->attend_link, &local->call_attend_q);
  65                 }
  66                 spin_unlock_bh(&local->lock);
  67                 rxrpc_wake_up_io_thread(local);
  68         }
  69 }
  70
  71 static void rxrpc_call_timer_expired(struct timer_list *t)
  72 {
  73         struct rxrpc_call *call = from_timer(call, t, timer);
  74
  75         _enter("%d", call->debug_id);
  76
  77         if (call->state < RXRPC_CALL_COMPLETE) {
  78                 trace_rxrpc_timer_expired(call, jiffies);
  79                 rxrpc_queue_call(call, rxrpc_call_queue_timer);
  80         }
  81 }
  82
  83 void rxrpc_reduce_call_timer(struct rxrpc_call *call,
  84                              unsigned long expire_at,
  85                              unsigned long now,
  86                              enum rxrpc_timer_trace why)
  87 {
  88         trace_rxrpc_timer(call, why, now);
  89         timer_reduce(&call->timer, expire_at);
  90 }
  91
  92 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
  93
  94 static void rxrpc_destroy_call(struct work_struct *);
  95
  96 /*
  97  * find an extant server call
  98  * - called in process context with IRQs enabled
  99  */
 100 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
 101                                               unsigned long user_call_ID)
 102 {
 103         struct rxrpc_call *call;
 104         struct rb_node *p;
 105
 106         _enter("%p,%lx", rx, user_call_ID);
 107
 108         read_lock(&rx->call_lock);
 109
 110         p = rx->calls.rb_node;
 111         while (p) {
 112                 call = rb_entry(p, struct rxrpc_call, sock_node);
 113
 114                 if (user_call_ID < call->user_call_ID)
 115                         p = p->rb_left;
 116                 else if (user_call_ID > call->user_call_ID)
 117                         p = p->rb_right;
 118                 else
 119                         goto found_extant_call;
 120         }
 121
 122         read_unlock(&rx->call_lock);
 123         _leave(" = NULL");
 124         return NULL;
 125
 126 found_extant_call:
 127         rxrpc_get_call(call, rxrpc_call_get_sendmsg);
 128         read_unlock(&rx->call_lock);
 129         _leave(" = %p [%d]", call, refcount_read(&call->ref));
 130         return call;
 131 }
 132
 133 /*
 134  * allocate a new call
 135  */
 136 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
 137                                     unsigned int debug_id)
 138 {
 139         struct rxrpc_call *call;
 140         struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
 141
 142         call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
 143         if (!call)
 144                 return NULL;
 145
 146         mutex_init(&call->user_mutex);
 147
 148         /* Prevent lockdep reporting a deadlock false positive between the afs
 149          * filesystem and sys_sendmsg() via the mmap sem.
 150          */
 151         if (rx->sk.sk_kern_sock)
 152                 lockdep_set_class(&call->user_mutex,
 153                                   &rxrpc_call_user_mutex_lock_class_key);
 154
 155         timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
 156         INIT_WORK(&call->processor, rxrpc_process_call);
 157         INIT_WORK(&call->destroyer, rxrpc_destroy_call);
 158         INIT_LIST_HEAD(&call->link);
 159         INIT_LIST_HEAD(&call->chan_wait_link);
 160         INIT_LIST_HEAD(&call->accept_link);
 161         INIT_LIST_HEAD(&call->recvmsg_link);
 162         INIT_LIST_HEAD(&call->sock_link);
 163         INIT_LIST_HEAD(&call->attend_link);
 164         INIT_LIST_HEAD(&call->tx_buffer);
 165         skb_queue_head_init(&call->recvmsg_queue);
 166         skb_queue_head_init(&call->rx_oos_queue);
 167         init_waitqueue_head(&call->waitq);
 168         spin_lock_init(&call->notify_lock);
 169         spin_lock_init(&call->tx_lock);
 170         spin_lock_init(&call->acks_ack_lock);
 171         rwlock_init(&call->state_lock);
 172         refcount_set(&call->ref, 1);
 173         call->debug_id = debug_id;
 174         call->tx_total_len = -1;
 175         call->next_rx_timo = 20 * HZ;
 176         call->next_req_timo = 1 * HZ;
 177         atomic64_set(&call->ackr_window, 0x100000001ULL);
 178
 179         memset(&call->sock_node, 0xed, sizeof(call->sock_node));
 180
 181         call->rx_winsize = rxrpc_rx_window_size;
 182         call->tx_winsize = 16;
 183
 184         if (RXRPC_TX_SMSS > 2190)
 185                 call->cong_cwnd = 2;
 186         else if (RXRPC_TX_SMSS > 1095)
 187                 call->cong_cwnd = 3;
 188         else
 189                 call->cong_cwnd = 4;
 190         call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
 191
 192         call->rxnet = rxnet;
 193         call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
 194         atomic_inc(&rxnet->nr_calls);
 195         return call;
 196 }
 197
 198 /*
 199  * Allocate a new client call.
 200  */
 201 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
 202                                                   struct sockaddr_rxrpc *srx,
 203                                                   gfp_t gfp,
 204                                                   unsigned int debug_id)
 205 {
 206         struct rxrpc_call *call;
 207         ktime_t now;
 208
 209         _enter("");
 210
 211         call = rxrpc_alloc_call(rx, gfp, debug_id);
 212         if (!call)
 213                 return ERR_PTR(-ENOMEM);
 214         call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
 215         call->service_id = srx->srx_service;
 216         now = ktime_get_real();
 217         call->acks_latest_ts = now;
 218         call->cong_tstamp = now;
 219
 220         _leave(" = %p", call);
 221         return call;
 222 }
 223
 224 /*
 225  * Initiate the call ack/resend/expiry timer.
 226  */
 227 static void rxrpc_start_call_timer(struct rxrpc_call *call)
 228 {
 229         unsigned long now = jiffies;
 230         unsigned long j = now + MAX_JIFFY_OFFSET;
 231
 232         call->delay_ack_at = j;
 233         call->ack_lost_at = j;
 234         call->resend_at = j;
 235         call->ping_at = j;
 236         call->expect_rx_by = j;
 237         call->expect_req_by = j;
 238         call->expect_term_by = j;
 239         call->timer.expires = now;
 240 }
 241
 242 /*
 243  * Wait for a call slot to become available.
 244  */
 245 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
 246 {
 247         struct semaphore *limiter = &rxrpc_call_limiter;
 248
 249         if (p->kernel)
 250                 limiter = &rxrpc_kernel_call_limiter;
 251         if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
 252                 down(limiter);
 253                 return limiter;
 254         }
 255         return down_interruptible(limiter) < 0 ? NULL : limiter;
 256 }
 257
 258 /*
 259  * Release a call slot.
 260  */
 261 static void rxrpc_put_call_slot(struct rxrpc_call *call)
 262 {
 263         struct semaphore *limiter = &rxrpc_call_limiter;
 264
 265         if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
 266                 limiter = &rxrpc_kernel_call_limiter;
 267         up(limiter);
 268 }
 269
 270 /*
 271  * Set up a call for the given parameters.
 272  * - Called with the socket lock held, which it must release.
 273  * - If it returns a call, the call's lock will need releasing by the caller.
 274  */
 275 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 276                                          struct rxrpc_conn_parameters *cp,
 277                                          struct sockaddr_rxrpc *srx,
 278                                          struct rxrpc_call_params *p,
 279                                          gfp_t gfp,
 280                                          unsigned int debug_id)
 281         __releases(&rx->sk.sk_lock.slock)
 282         __acquires(&call->user_mutex)
 283 {
 284         struct rxrpc_call *call, *xcall;
 285         struct rxrpc_net *rxnet;
 286         struct semaphore *limiter;
 287         struct rb_node *parent, **pp;
 288         int ret;
 289
 290         _enter("%p,%lx", rx, p->user_call_ID);
 291
 292         limiter = rxrpc_get_call_slot(p, gfp);
 293         if (!limiter) {
 294                 release_sock(&rx->sk);
 295                 return ERR_PTR(-ERESTARTSYS);
 296         }
 297
 298         call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
 299         if (IS_ERR(call)) {
 300                 release_sock(&rx->sk);
 301                 up(limiter);
 302                 _leave(" = %ld", PTR_ERR(call));
 303                 return call;
 304         }
 305
 306         call->interruptibility = p->interruptibility;
 307         call->tx_total_len = p->tx_total_len;
 308         trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
 309                          p->user_call_ID, rxrpc_call_new_client);
 310         if (p->kernel)
 311                 __set_bit(RXRPC_CALL_KERNEL, &call->flags);
 312
 313         /* We need to protect a partially set up call against the user as we
 314          * will be acting outside the socket lock.
 315          */
 316         mutex_lock(&call->user_mutex);
 317
 318         /* Publish the call, even though it is incompletely set up as yet */
 319         write_lock(&rx->call_lock);
 320
 321         pp = &rx->calls.rb_node;
 322         parent = NULL;
 323         while (*pp) {
 324                 parent = *pp;
 325                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 326
 327                 if (p->user_call_ID < xcall->user_call_ID)
 328                         pp = &(*pp)->rb_left;
 329                 else if (p->user_call_ID > xcall->user_call_ID)
 330                         pp = &(*pp)->rb_right;
 331                 else
 332                         goto error_dup_user_ID;
 333         }
 334
 335         rcu_assign_pointer(call->socket, rx);
 336         call->user_call_ID = p->user_call_ID;
 337         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 338         rxrpc_get_call(call, rxrpc_call_get_userid);
 339         rb_link_node(&call->sock_node, parent, pp);
 340         rb_insert_color(&call->sock_node, &rx->calls);
 341         list_add(&call->sock_link, &rx->sock_calls);
 342
 343         write_unlock(&rx->call_lock);
 344
 345         rxnet = call->rxnet;
 346         spin_lock_bh(&rxnet->call_lock);
 347         list_add_tail_rcu(&call->link, &rxnet->calls);
 348         spin_unlock_bh(&rxnet->call_lock);
 349
 350         /* From this point on, the call is protected by its own lock. */
 351         release_sock(&rx->sk);
 352
 353         /* Set up or get a connection record and set the protocol parameters,
 354          * including channel number and call ID.
 355          */
 356         ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
 357         if (ret < 0)
 358                 goto error_attached_to_socket;
 359
 360         rxrpc_see_call(call, rxrpc_call_see_connected);
 361
 362         rxrpc_start_call_timer(call);
 363
 364         _leave(" = %p [new]", call);
 365         return call;
 366
 367         /* We unexpectedly found the user ID in the list after taking
 368          * the call_lock.  This shouldn't happen unless the user races
 369          * with itself and tries to add the same user ID twice at the
 370          * same time in different threads.
 371          */
 372 error_dup_user_ID:
 373         write_unlock(&rx->call_lock);
 374         release_sock(&rx->sk);
 375         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 376                                     RX_CALL_DEAD, -EEXIST);
 377         trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
 378                          rxrpc_call_see_userid_exists);
 379         rxrpc_release_call(rx, call);
 380         mutex_unlock(&call->user_mutex);
 381         rxrpc_put_call(call, rxrpc_call_put_userid_exists);
 382         _leave(" = -EEXIST");
 383         return ERR_PTR(-EEXIST);
 384
 385         /* We got an error, but the call is attached to the socket and is in
 386          * need of release.  However, we might now race with recvmsg() when
 387          * completing the call queues it.  Return 0 from sys_sendmsg() and
 388          * leave the error to recvmsg() to deal with.
 389          */
 390 error_attached_to_socket:
 391         trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
 392                          rxrpc_call_see_connect_failed);
 393         set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
 394         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 395                                     RX_CALL_DEAD, ret);
 396         _leave(" = c=%08x [err]", call->debug_id);
 397         return call;
 398 }
 399
 400 /*
 401  * Set up an incoming call.  call->conn points to the connection.
 402  * This is called in BH context and isn't allowed to fail.
 403  */
 404 void rxrpc_incoming_call(struct rxrpc_sock *rx,
 405                          struct rxrpc_call *call,
 406                          struct sk_buff *skb)
 407 {
 408         struct rxrpc_connection *conn = call->conn;
 409         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 410         u32 chan;
 411
 412         _enter(",%d", call->conn->debug_id);
 413
 414         rcu_assign_pointer(call->socket, rx);
 415         call->call_id           = sp->hdr.callNumber;
 416         call->service_id        = sp->hdr.serviceId;
 417         call->cid               = sp->hdr.cid;
 418         call->state             = RXRPC_CALL_SERVER_SECURING;
 419         call->cong_tstamp       = skb->tstamp;
 420
 421         /* Set the channel for this call.  We don't get channel_lock as we're
 422          * only defending against the data_ready handler (which we're called
 423          * from) and the RESPONSE packet parser (which is only really
 424          * interested in call_counter and can cope with a disagreement with the
 425          * call pointer).
 426          */
 427         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 428         conn->channels[chan].call_counter = call->call_id;
 429         conn->channels[chan].call_id = call->call_id;
 430         rcu_assign_pointer(conn->channels[chan].call, call);
 431
 432         spin_lock(&conn->peer->lock);
 433         hlist_add_head_rcu(&call->error_link, &conn->peer->error_targets);
 434         spin_unlock(&conn->peer->lock);
 435
 436         rxrpc_start_call_timer(call);
 437         _leave("");
 438 }
 439
 440 /*
 441  * Queue a call's work processor.
 442  */
 443 void rxrpc_queue_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
 444 {
 445         if (rxrpc_queue_work(&call->processor))
 446                 trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0, why);
 447 }
 448
 449 /*
 450  * Note the re-emergence of a call.
 451  */
 452 void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
 453 {
 454         if (call) {
 455                 int r = refcount_read(&call->ref);
 456
 457                 trace_rxrpc_call(call->debug_id, r, 0, why);
 458         }
 459 }
 460
 461 bool rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
 462 {
 463         int r;
 464
 465         if (!__refcount_inc_not_zero(&call->ref, &r))
 466                 return false;
 467         trace_rxrpc_call(call->debug_id, r + 1, 0, why);
 468         return true;
 469 }
 470
 471 /*
 472  * Note the addition of a ref on a call.
 473  */
 474 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
 475 {
 476         int r;
 477
 478         __refcount_inc(&call->ref, &r);
 479         trace_rxrpc_call(call->debug_id, r + 1, 0, why);
 480 }
 481
 482 /*
 483  * Clean up the Rx skb ring.
 484  */
 485 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
 486 {
 487         skb_queue_purge(&call->recvmsg_queue);
 488         skb_queue_purge(&call->rx_oos_queue);
 489 }
 490
 491 /*
 492  * Detach a call from its owning socket.
 493  */
 494 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 495 {
 496         struct rxrpc_connection *conn = call->conn;
 497         bool put = false;
 498
 499         _enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
 500
 501         trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
 502                          call->flags, rxrpc_call_see_release);
 503
 504         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 505
 506         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 507                 BUG();
 508
 509         rxrpc_put_call_slot(call);
 510         del_timer_sync(&call->timer);
 511
 512         /* Make sure we don't get any more notifications */
 513         write_lock_bh(&rx->recvmsg_lock);
 514
 515         if (!list_empty(&call->recvmsg_link)) {
 516                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 517                        call, call->events, call->flags);
 518                 list_del(&call->recvmsg_link);
 519                 put = true;
 520         }
 521
 522         /* list_empty() must return false in rxrpc_notify_socket() */
 523         call->recvmsg_link.next = NULL;
 524         call->recvmsg_link.prev = NULL;
 525
 526         write_unlock_bh(&rx->recvmsg_lock);
 527         if (put)
 528                 rxrpc_put_call(call, rxrpc_call_put_unnotify);
 529
 530         write_lock(&rx->call_lock);
 531
 532         if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 533                 rb_erase(&call->sock_node, &rx->calls);
 534                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 535                 rxrpc_put_call(call, rxrpc_call_put_userid_exists);
 536         }
 537
 538         list_del(&call->sock_link);
 539         write_unlock(&rx->call_lock);
 540
 541         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
 542
 543         if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
 544                 rxrpc_disconnect_call(call);
 545         if (call->security)
 546                 call->security->free_call_crypto(call);
 547         _leave("");
 548 }
 549
 550 /*
 551  * release all the calls associated with a socket
 552  */
 553 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 554 {
 555         struct rxrpc_call *call;
 556
 557         _enter("%p", rx);
 558
 559         while (!list_empty(&rx->to_be_accepted)) {
 560                 call = list_entry(rx->to_be_accepted.next,
 561                                   struct rxrpc_call, accept_link);
 562                 list_del(&call->accept_link);
 563                 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
 564                 rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
 565         }
 566
 567         while (!list_empty(&rx->sock_calls)) {
 568                 call = list_entry(rx->sock_calls.next,
 569                                   struct rxrpc_call, sock_link);
 570                 rxrpc_get_call(call, rxrpc_call_get_release_sock);
 571                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
 572                 rxrpc_send_abort_packet(call);
 573                 rxrpc_release_call(rx, call);
 574                 rxrpc_put_call(call, rxrpc_call_put_release_sock);
 575         }
 576
 577         _leave("");
 578 }
 579
 580 /*
 581  * release a call
 582  */
 583 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
 584 {
 585         struct rxrpc_net *rxnet = call->rxnet;
 586         unsigned int debug_id = call->debug_id;
 587         bool dead;
 588         int r;
 589
 590         ASSERT(call != NULL);
 591
 592         dead = __refcount_dec_and_test(&call->ref, &r);
 593         trace_rxrpc_call(debug_id, r - 1, 0, why);
 594         if (dead) {
 595                 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 596
 597                 if (!list_empty(&call->link)) {
 598                         spin_lock_bh(&rxnet->call_lock);
 599                         list_del_init(&call->link);
 600                         spin_unlock_bh(&rxnet->call_lock);
 601                 }
 602
 603                 rxrpc_cleanup_call(call);
 604         }
 605 }
 606
 607 /*
 608  * Free up the call under RCU.
 609  */
 610 static void rxrpc_rcu_free_call(struct rcu_head *rcu)
 611 {
 612         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 613         struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
 614
 615         kmem_cache_free(rxrpc_call_jar, call);
 616         if (atomic_dec_and_test(&rxnet->nr_calls))
 617                 wake_up_var(&rxnet->nr_calls);
 618 }
 619
 620 /*
 621  * Final call destruction - but must be done in process context.
 622  */
 623 static void rxrpc_destroy_call(struct work_struct *work)
 624 {
 625         struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
 626         struct rxrpc_txbuf *txb;
 627
 628         del_timer_sync(&call->timer);
 629         cancel_work_sync(&call->processor); /* The processor may restart the timer */
 630         del_timer_sync(&call->timer);
 631
 632         rxrpc_cleanup_ring(call);
 633         while ((txb = list_first_entry_or_null(&call->tx_buffer,
 634                                                struct rxrpc_txbuf, call_link))) {
 635                 list_del(&txb->call_link);
 636                 rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
 637         }
 638         rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
 639         rxrpc_free_skb(call->acks_soft_tbl, rxrpc_skb_put_ack);
 640         rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
 641         rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
 642         call_rcu(&call->rcu, rxrpc_rcu_free_call);
 643 }
 644
 645 /*
 646  * clean up a call
 647  */
 648 void rxrpc_cleanup_call(struct rxrpc_call *call)
 649 {
 650         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 651
 652         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 653         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 654
 655         del_timer_sync(&call->timer);
 656         cancel_work(&call->processor);
 657
 658         if (rcu_read_lock_held() || work_busy(&call->processor))
 659                 /* Can't use the rxrpc workqueue as we need to cancel/flush
 660                  * something that may be running/waiting there.
 661                  */
 662                 schedule_work(&call->destroyer);
 663         else
 664                 rxrpc_destroy_call(&call->destroyer);
 665 }
 666
 667 /*
 668  * Make sure that all calls are gone from a network namespace.  To reach this
 669  * point, any open UDP sockets in that namespace must have been closed, so any
 670  * outstanding calls cannot be doing I/O.
 671  */
 672 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
 673 {
 674         struct rxrpc_call *call;
 675
 676         _enter("");
 677
 678         if (!list_empty(&rxnet->calls)) {
 679                 spin_lock_bh(&rxnet->call_lock);
 680
 681                 while (!list_empty(&rxnet->calls)) {
 682                         call = list_entry(rxnet->calls.next,
 683                                           struct rxrpc_call, link);
 684                         _debug("Zapping call %p", call);
 685
 686                         rxrpc_see_call(call, rxrpc_call_see_zap);
 687                         list_del_init(&call->link);
 688
 689                         pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
 690                                call, refcount_read(&call->ref),
 691                                rxrpc_call_states[call->state],
 692                                call->flags, call->events);
 693
 694                         spin_unlock_bh(&rxnet->call_lock);
 695                         cond_resched();
 696                         spin_lock_bh(&rxnet->call_lock);
 697                 }
 698
 699                 spin_unlock_bh(&rxnet->call_lock);
 700         }
 701
 702         atomic_dec(&rxnet->nr_calls);
 703         wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
 704 }