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