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