ar-call.c 21.2 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822
/* RxRPC individual remote procedure call handling
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/circ_buf.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"

const char *const rxrpc_call_states[] = {
	[RXRPC_CALL_CLIENT_SEND_REQUEST]	= "ClSndReq",
	[RXRPC_CALL_CLIENT_AWAIT_REPLY]		= "ClAwtRpl",
	[RXRPC_CALL_CLIENT_RECV_REPLY]		= "ClRcvRpl",
	[RXRPC_CALL_CLIENT_FINAL_ACK]		= "ClFnlACK",
	[RXRPC_CALL_SERVER_SECURING]		= "SvSecure",
	[RXRPC_CALL_SERVER_ACCEPTING]		= "SvAccept",
	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
	[RXRPC_CALL_COMPLETE]			= "Complete",
	[RXRPC_CALL_SERVER_BUSY]		= "SvBusy  ",
	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
	[RXRPC_CALL_DEAD]			= "Dead    ",
};

struct kmem_cache *rxrpc_call_jar;
LIST_HEAD(rxrpc_calls);
DEFINE_RWLOCK(rxrpc_call_lock);
static unsigned int rxrpc_call_max_lifetime = 60;
static unsigned int rxrpc_dead_call_timeout = 2;

static void rxrpc_destroy_call(struct work_struct *work);
static void rxrpc_call_life_expired(unsigned long _call);
static void rxrpc_dead_call_expired(unsigned long _call);
static void rxrpc_ack_time_expired(unsigned long _call);
static void rxrpc_resend_time_expired(unsigned long _call);

/*
 * allocate a new call
 */
static struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
{
	struct rxrpc_call *call;

	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
	if (!call)
		return NULL;

	call->acks_winsz = 16;
	call->acks_window = kmalloc(call->acks_winsz * sizeof(unsigned long),
				    gfp);
	if (!call->acks_window) {
		kmem_cache_free(rxrpc_call_jar, call);
		return NULL;
	}

	setup_timer(&call->lifetimer, &rxrpc_call_life_expired,
		    (unsigned long) call);
	setup_timer(&call->deadspan, &rxrpc_dead_call_expired,
		    (unsigned long) call);
	setup_timer(&call->ack_timer, &rxrpc_ack_time_expired,
		    (unsigned long) call);
	setup_timer(&call->resend_timer, &rxrpc_resend_time_expired,
		    (unsigned long) call);
	INIT_WORK(&call->destroyer, &rxrpc_destroy_call);
	INIT_WORK(&call->processor, &rxrpc_process_call);
	INIT_LIST_HEAD(&call->accept_link);
	skb_queue_head_init(&call->rx_queue);
	skb_queue_head_init(&call->rx_oos_queue);
	init_waitqueue_head(&call->tx_waitq);
	spin_lock_init(&call->lock);
	rwlock_init(&call->state_lock);
	atomic_set(&call->usage, 1);
	call->debug_id = atomic_inc_return(&rxrpc_debug_id);
	call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;

	memset(&call->sock_node, 0xed, sizeof(call->sock_node));

	call->rx_data_expect = 1;
	call->rx_data_eaten = 0;
	call->rx_first_oos = 0;
	call->ackr_win_top = call->rx_data_eaten + 1 + RXRPC_MAXACKS;
	call->creation_jif = jiffies;
	return call;
}

/*
 * allocate a new client call and attempt to get a connection slot for it
 */
static struct rxrpc_call *rxrpc_alloc_client_call(
	struct rxrpc_sock *rx,
	struct rxrpc_transport *trans,
	struct rxrpc_conn_bundle *bundle,
	gfp_t gfp)
{
	struct rxrpc_call *call;
	int ret;

	_enter("");

	ASSERT(rx != NULL);
	ASSERT(trans != NULL);
	ASSERT(bundle != NULL);

	call = rxrpc_alloc_call(gfp);
	if (!call)
		return ERR_PTR(-ENOMEM);

	sock_hold(&rx->sk);
	call->socket = rx;
	call->rx_data_post = 1;

	ret = rxrpc_connect_call(rx, trans, bundle, call, gfp);
	if (ret < 0) {
		kmem_cache_free(rxrpc_call_jar, call);
		return ERR_PTR(ret);
	}

	spin_lock(&call->conn->trans->peer->lock);
	list_add(&call->error_link, &call->conn->trans->peer->error_targets);
	spin_unlock(&call->conn->trans->peer->lock);

	call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
	add_timer(&call->lifetimer);

	_leave(" = %p", call);
	return call;
}

/*
 * set up a call for the given data
 * - called in process context with IRQs enabled
 */
struct rxrpc_call *rxrpc_get_client_call(struct rxrpc_sock *rx,
					 struct rxrpc_transport *trans,
					 struct rxrpc_conn_bundle *bundle,
					 unsigned long user_call_ID,
					 int create,
					 gfp_t gfp)
{
	struct rxrpc_call *call, *candidate;
	struct rb_node *p, *parent, **pp;

	_enter("%p,%d,%d,%lx,%d",
	       rx, trans ? trans->debug_id : -1, bundle ? bundle->debug_id : -1,
	       user_call_ID, create);

	/* search the extant calls first for one that matches the specified
	 * user ID */
	read_lock(&rx->call_lock);

	p = rx->calls.rb_node;
	while (p) {
		call = rb_entry(p, struct rxrpc_call, sock_node);

		if (user_call_ID < call->user_call_ID)
			p = p->rb_left;
		else if (user_call_ID > call->user_call_ID)
			p = p->rb_right;
		else
			goto found_extant_call;
	}

	read_unlock(&rx->call_lock);

	if (!create || !trans)
		return ERR_PTR(-EBADSLT);

	/* not yet present - create a candidate for a new record and then
	 * redo the search */
	candidate = rxrpc_alloc_client_call(rx, trans, bundle, gfp);
	if (IS_ERR(candidate)) {
		_leave(" = %ld", PTR_ERR(candidate));
		return candidate;
	}

	candidate->user_call_ID = user_call_ID;
	__set_bit(RXRPC_CALL_HAS_USERID, &candidate->flags);

	write_lock(&rx->call_lock);

	pp = &rx->calls.rb_node;
	parent = NULL;
	while (*pp) {
		parent = *pp;
		call = rb_entry(parent, struct rxrpc_call, sock_node);

		if (user_call_ID < call->user_call_ID)
			pp = &(*pp)->rb_left;
		else if (user_call_ID > call->user_call_ID)
			pp = &(*pp)->rb_right;
		else
			goto found_extant_second;
	}

	/* second search also failed; add the new call */
	call = candidate;
	candidate = NULL;
	rxrpc_get_call(call);

	rb_link_node(&call->sock_node, parent, pp);
	rb_insert_color(&call->sock_node, &rx->calls);
	write_unlock(&rx->call_lock);

	write_lock_bh(&rxrpc_call_lock);
	list_add_tail(&call->link, &rxrpc_calls);
	write_unlock_bh(&rxrpc_call_lock);

	_net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);

	_leave(" = %p [new]", call);
	return call;

	/* we found the call in the list immediately */
found_extant_call:
	rxrpc_get_call(call);
	read_unlock(&rx->call_lock);
	_leave(" = %p [extant %d]", call, atomic_read(&call->usage));
	return call;

	/* we found the call on the second time through the list */
found_extant_second:
	rxrpc_get_call(call);
	write_unlock(&rx->call_lock);
	rxrpc_put_call(candidate);
	_leave(" = %p [second %d]", call, atomic_read(&call->usage));
	return call;
}

/*
 * set up an incoming call
 * - called in process context with IRQs enabled
 */
struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
				       struct rxrpc_connection *conn,
				       struct rxrpc_header *hdr,
				       gfp_t gfp)
{
	struct rxrpc_call *call, *candidate;
	struct rb_node **p, *parent;
	__be32 call_id;

	_enter(",%d,,%x", conn->debug_id, gfp);

	ASSERT(rx != NULL);

	candidate = rxrpc_alloc_call(gfp);
	if (!candidate)
		return ERR_PTR(-EBUSY);

	candidate->socket = rx;
	candidate->conn = conn;
	candidate->cid = hdr->cid;
	candidate->call_id = hdr->callNumber;
	candidate->channel = ntohl(hdr->cid) & RXRPC_CHANNELMASK;
	candidate->rx_data_post = 0;
	candidate->state = RXRPC_CALL_SERVER_ACCEPTING;
	if (conn->security_ix > 0)
		candidate->state = RXRPC_CALL_SERVER_SECURING;

	write_lock_bh(&conn->lock);

	/* set the channel for this call */
	call = conn->channels[candidate->channel];
	_debug("channel[%u] is %p", candidate->channel, call);
	if (call && call->call_id == hdr->callNumber) {
		/* already set; must've been a duplicate packet */
		_debug("extant call [%d]", call->state);
		ASSERTCMP(call->conn, ==, conn);

		read_lock(&call->state_lock);
		switch (call->state) {
		case RXRPC_CALL_LOCALLY_ABORTED:
			if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events))
				rxrpc_queue_call(call);
		case RXRPC_CALL_REMOTELY_ABORTED:
			read_unlock(&call->state_lock);
			goto aborted_call;
		default:
			rxrpc_get_call(call);
			read_unlock(&call->state_lock);
			goto extant_call;
		}
	}

	if (call) {
		/* it seems the channel is still in use from the previous call
		 * - ditch the old binding if its call is now complete */
		_debug("CALL: %u { %s }",
		       call->debug_id, rxrpc_call_states[call->state]);

		if (call->state >= RXRPC_CALL_COMPLETE) {
			conn->channels[call->channel] = NULL;
		} else {
			write_unlock_bh(&conn->lock);
			kmem_cache_free(rxrpc_call_jar, candidate);
			_leave(" = -EBUSY");
			return ERR_PTR(-EBUSY);
		}
	}

	/* check the call number isn't duplicate */
	_debug("check dup");
	call_id = hdr->callNumber;
	p = &conn->calls.rb_node;
	parent = NULL;
	while (*p) {
		parent = *p;
		call = rb_entry(parent, struct rxrpc_call, conn_node);

		if (call_id < call->call_id)
			p = &(*p)->rb_left;
		else if (call_id > call->call_id)
			p = &(*p)->rb_right;
		else
			goto old_call;
	}

	/* make the call available */
	_debug("new call");
	call = candidate;
	candidate = NULL;
	rb_link_node(&call->conn_node, parent, p);
	rb_insert_color(&call->conn_node, &conn->calls);
	conn->channels[call->channel] = call;
	sock_hold(&rx->sk);
	atomic_inc(&conn->usage);
	write_unlock_bh(&conn->lock);

	spin_lock(&conn->trans->peer->lock);
	list_add(&call->error_link, &conn->trans->peer->error_targets);
	spin_unlock(&conn->trans->peer->lock);

	write_lock_bh(&rxrpc_call_lock);
	list_add_tail(&call->link, &rxrpc_calls);
	write_unlock_bh(&rxrpc_call_lock);

	_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);

	call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ;
	add_timer(&call->lifetimer);
	_leave(" = %p {%d} [new]", call, call->debug_id);
	return call;

extant_call:
	write_unlock_bh(&conn->lock);
	kmem_cache_free(rxrpc_call_jar, candidate);
	_leave(" = %p {%d} [extant]", call, call ? call->debug_id : -1);
	return call;

aborted_call:
	write_unlock_bh(&conn->lock);
	kmem_cache_free(rxrpc_call_jar, candidate);
	_leave(" = -ECONNABORTED");
	return ERR_PTR(-ECONNABORTED);

old_call:
	write_unlock_bh(&conn->lock);
	kmem_cache_free(rxrpc_call_jar, candidate);
	_leave(" = -ECONNRESET [old]");
	return ERR_PTR(-ECONNRESET);
}

/*
 * find an extant server call
 * - called in process context with IRQs enabled
 */
struct rxrpc_call *rxrpc_find_server_call(struct rxrpc_sock *rx,
					  unsigned long user_call_ID)
{
	struct rxrpc_call *call;
	struct rb_node *p;

	_enter("%p,%lx", rx, user_call_ID);

	/* search the extant calls for one that matches the specified user
	 * ID */
	read_lock(&rx->call_lock);

	p = rx->calls.rb_node;
	while (p) {
		call = rb_entry(p, struct rxrpc_call, sock_node);

		if (user_call_ID < call->user_call_ID)
			p = p->rb_left;
		else if (user_call_ID > call->user_call_ID)
			p = p->rb_right;
		else
			goto found_extant_call;
	}

	read_unlock(&rx->call_lock);
	_leave(" = NULL");
	return NULL;

	/* we found the call in the list immediately */
found_extant_call:
	rxrpc_get_call(call);
	read_unlock(&rx->call_lock);
	_leave(" = %p [%d]", call, atomic_read(&call->usage));
	return call;
}

/*
 * detach a call from a socket and set up for release
 */
void rxrpc_release_call(struct rxrpc_call *call)
{
	struct rxrpc_connection *conn = call->conn;
	struct rxrpc_sock *rx = call->socket;

	_enter("{%d,%d,%d,%d}",
	       call->debug_id, atomic_read(&call->usage),
	       atomic_read(&call->ackr_not_idle),
	       call->rx_first_oos);

	spin_lock_bh(&call->lock);
	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
		BUG();
	spin_unlock_bh(&call->lock);

	/* dissociate from the socket
	 * - the socket's ref on the call is passed to the death timer
	 */
	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);

	write_lock_bh(&rx->call_lock);
	if (!list_empty(&call->accept_link)) {
		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
		       call, call->events, call->flags);
		ASSERT(!test_bit(RXRPC_CALL_HAS_USERID, &call->flags));
		list_del_init(&call->accept_link);
		sk_acceptq_removed(&rx->sk);
	} else if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
		rb_erase(&call->sock_node, &rx->calls);
		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
		clear_bit(RXRPC_CALL_HAS_USERID, &call->flags);
	}
	write_unlock_bh(&rx->call_lock);

	/* free up the channel for reuse */
	spin_lock(&conn->trans->client_lock);
	write_lock_bh(&conn->lock);
	write_lock(&call->state_lock);

	if (conn->channels[call->channel] == call)
		conn->channels[call->channel] = NULL;

	if (conn->out_clientflag && conn->bundle) {
		conn->avail_calls++;
		switch (conn->avail_calls) {
		case 1:
			list_move_tail(&conn->bundle_link,
				       &conn->bundle->avail_conns);
		case 2 ... RXRPC_MAXCALLS - 1:
			ASSERT(conn->channels[0] == NULL ||
			       conn->channels[1] == NULL ||
			       conn->channels[2] == NULL ||
			       conn->channels[3] == NULL);
			break;
		case RXRPC_MAXCALLS:
			list_move_tail(&conn->bundle_link,
				       &conn->bundle->unused_conns);
			ASSERT(conn->channels[0] == NULL &&
			       conn->channels[1] == NULL &&
			       conn->channels[2] == NULL &&
			       conn->channels[3] == NULL);
			break;
		default:
			printk(KERN_ERR "RxRPC: conn->avail_calls=%d\n",
			       conn->avail_calls);
			BUG();
		}
	}

	spin_unlock(&conn->trans->client_lock);

	if (call->state < RXRPC_CALL_COMPLETE &&
	    call->state != RXRPC_CALL_CLIENT_FINAL_ACK) {
		_debug("+++ ABORTING STATE %d +++\n", call->state);
		call->state = RXRPC_CALL_LOCALLY_ABORTED;
		call->abort_code = RX_CALL_DEAD;
		set_bit(RXRPC_CALL_ABORT, &call->events);
		rxrpc_queue_call(call);
	}
	write_unlock(&call->state_lock);
	write_unlock_bh(&conn->lock);

	/* clean up the Rx queue */
	if (!skb_queue_empty(&call->rx_queue) ||
	    !skb_queue_empty(&call->rx_oos_queue)) {
		struct rxrpc_skb_priv *sp;
		struct sk_buff *skb;

		_debug("purge Rx queues");

		spin_lock_bh(&call->lock);
		while ((skb = skb_dequeue(&call->rx_queue)) ||
		       (skb = skb_dequeue(&call->rx_oos_queue))) {
			sp = rxrpc_skb(skb);
			if (sp->call) {
				ASSERTCMP(sp->call, ==, call);
				rxrpc_put_call(call);
				sp->call = NULL;
			}
			skb->destructor = NULL;
			spin_unlock_bh(&call->lock);

			_debug("- zap %s %%%u #%u",
			       rxrpc_pkts[sp->hdr.type],
			       ntohl(sp->hdr.serial),
			       ntohl(sp->hdr.seq));
			rxrpc_free_skb(skb);
			spin_lock_bh(&call->lock);
		}
		spin_unlock_bh(&call->lock);

		ASSERTCMP(call->state, !=, RXRPC_CALL_COMPLETE);
	}

	del_timer_sync(&call->resend_timer);
	del_timer_sync(&call->ack_timer);
	del_timer_sync(&call->lifetimer);
	call->deadspan.expires = jiffies + rxrpc_dead_call_timeout * HZ;
	add_timer(&call->deadspan);

	_leave("");
}

/*
 * handle a dead call being ready for reaping
 */
static void rxrpc_dead_call_expired(unsigned long _call)
{
	struct rxrpc_call *call = (struct rxrpc_call *) _call;

	_enter("{%d}", call->debug_id);

	write_lock_bh(&call->state_lock);
	call->state = RXRPC_CALL_DEAD;
	write_unlock_bh(&call->state_lock);
	rxrpc_put_call(call);
}

/*
 * mark a call as to be released, aborting it if it's still in progress
 * - called with softirqs disabled
 */
static void rxrpc_mark_call_released(struct rxrpc_call *call)
{
	bool sched;

	write_lock(&call->state_lock);
	if (call->state < RXRPC_CALL_DEAD) {
		sched = false;
		if (call->state < RXRPC_CALL_COMPLETE) {
			_debug("abort call %p", call);
			call->state = RXRPC_CALL_LOCALLY_ABORTED;
			call->abort_code = RX_CALL_DEAD;
			if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events))
				sched = true;
		}
		if (!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
			sched = true;
		if (sched)
			rxrpc_queue_call(call);
	}
	write_unlock(&call->state_lock);
}

/*
 * release all the calls associated with a socket
 */
void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
{
	struct rxrpc_call *call;
	struct rb_node *p;

	_enter("%p", rx);

	read_lock_bh(&rx->call_lock);

	/* mark all the calls as no longer wanting incoming packets */
	for (p = rb_first(&rx->calls); p; p = rb_next(p)) {
		call = rb_entry(p, struct rxrpc_call, sock_node);
		rxrpc_mark_call_released(call);
	}

	/* kill the not-yet-accepted incoming calls */
	list_for_each_entry(call, &rx->secureq, accept_link) {
		rxrpc_mark_call_released(call);
	}

	list_for_each_entry(call, &rx->acceptq, accept_link) {
		rxrpc_mark_call_released(call);
	}

	read_unlock_bh(&rx->call_lock);
	_leave("");
}

/*
 * release a call
 */
void __rxrpc_put_call(struct rxrpc_call *call)
{
	ASSERT(call != NULL);

	_enter("%p{u=%d}", call, atomic_read(&call->usage));

	ASSERTCMP(atomic_read(&call->usage), >, 0);

	if (atomic_dec_and_test(&call->usage)) {
		_debug("call %d dead", call->debug_id);
		ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
		rxrpc_queue_work(&call->destroyer);
	}
	_leave("");
}

/*
 * clean up a call
 */
static void rxrpc_cleanup_call(struct rxrpc_call *call)
{
	_net("DESTROY CALL %d", call->debug_id);

	ASSERT(call->socket);

	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));

	del_timer_sync(&call->lifetimer);
	del_timer_sync(&call->deadspan);
	del_timer_sync(&call->ack_timer);
	del_timer_sync(&call->resend_timer);

	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
	ASSERTCMP(call->events, ==, 0);
	if (work_pending(&call->processor)) {
		_debug("defer destroy");
		rxrpc_queue_work(&call->destroyer);
		return;
	}

	if (call->conn) {
		spin_lock(&call->conn->trans->peer->lock);
		list_del(&call->error_link);
		spin_unlock(&call->conn->trans->peer->lock);

		write_lock_bh(&call->conn->lock);
		rb_erase(&call->conn_node, &call->conn->calls);
		write_unlock_bh(&call->conn->lock);
		rxrpc_put_connection(call->conn);
	}

	if (call->acks_window) {
		_debug("kill Tx window %d",
		       CIRC_CNT(call->acks_head, call->acks_tail,
				call->acks_winsz));
		smp_mb();
		while (CIRC_CNT(call->acks_head, call->acks_tail,
				call->acks_winsz) > 0) {
			struct rxrpc_skb_priv *sp;
			unsigned long _skb;

			_skb = call->acks_window[call->acks_tail] & ~1;
			sp = rxrpc_skb((struct sk_buff *) _skb);
			_debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
			rxrpc_free_skb((struct sk_buff *) _skb);
			call->acks_tail =
				(call->acks_tail + 1) & (call->acks_winsz - 1);
		}

		kfree(call->acks_window);
	}

	rxrpc_free_skb(call->tx_pending);

	rxrpc_purge_queue(&call->rx_queue);
	ASSERT(skb_queue_empty(&call->rx_oos_queue));
	sock_put(&call->socket->sk);
	kmem_cache_free(rxrpc_call_jar, call);
}

/*
 * destroy a call
 */
static void rxrpc_destroy_call(struct work_struct *work)
{
	struct rxrpc_call *call =
		container_of(work, struct rxrpc_call, destroyer);

	_enter("%p{%d,%d,%p}",
	       call, atomic_read(&call->usage), call->channel, call->conn);

	ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);

	write_lock_bh(&rxrpc_call_lock);
	list_del_init(&call->link);
	write_unlock_bh(&rxrpc_call_lock);

	rxrpc_cleanup_call(call);
	_leave("");
}

/*
 * preemptively destroy all the call records from a transport endpoint rather
 * than waiting for them to time out
 */
void __exit rxrpc_destroy_all_calls(void)
{
	struct rxrpc_call *call;

	_enter("");
	write_lock_bh(&rxrpc_call_lock);

	while (!list_empty(&rxrpc_calls)) {
		call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
		_debug("Zapping call %p", call);

		list_del_init(&call->link);

		switch (atomic_read(&call->usage)) {
		case 0:
			ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
			break;
		case 1:
			if (del_timer_sync(&call->deadspan) != 0 &&
			    call->state != RXRPC_CALL_DEAD)
				rxrpc_dead_call_expired((unsigned long) call);
			if (call->state != RXRPC_CALL_DEAD)
				break;
		default:
			printk(KERN_ERR "RXRPC:"
			       " Call %p still in use (%d,%d,%s,%lx,%lx)!\n",
			       call, atomic_read(&call->usage),
			       atomic_read(&call->ackr_not_idle),
			       rxrpc_call_states[call->state],
			       call->flags, call->events);
			if (!skb_queue_empty(&call->rx_queue))
				printk(KERN_ERR"RXRPC: Rx queue occupied\n");
			if (!skb_queue_empty(&call->rx_oos_queue))
				printk(KERN_ERR"RXRPC: OOS queue occupied\n");
			break;
		}

		write_unlock_bh(&rxrpc_call_lock);
		cond_resched();
		write_lock_bh(&rxrpc_call_lock);
	}

	write_unlock_bh(&rxrpc_call_lock);
	_leave("");
}

/*
 * handle call lifetime being exceeded
 */
static void rxrpc_call_life_expired(unsigned long _call)
{
	struct rxrpc_call *call = (struct rxrpc_call *) _call;

	if (call->state >= RXRPC_CALL_COMPLETE)
		return;

	_enter("{%d}", call->debug_id);
	read_lock_bh(&call->state_lock);
	if (call->state < RXRPC_CALL_COMPLETE) {
		set_bit(RXRPC_CALL_LIFE_TIMER, &call->events);
		rxrpc_queue_call(call);
	}
	read_unlock_bh(&call->state_lock);
}

/*
 * handle resend timer expiry
 * - may not take call->state_lock as this can deadlock against del_timer_sync()
 */
static void rxrpc_resend_time_expired(unsigned long _call)
{
	struct rxrpc_call *call = (struct rxrpc_call *) _call;

	_enter("{%d}", call->debug_id);

	if (call->state >= RXRPC_CALL_COMPLETE)
		return;

	clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
	if (!test_and_set_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
		rxrpc_queue_call(call);
}

/*
 * handle ACK timer expiry
 */
static void rxrpc_ack_time_expired(unsigned long _call)
{
	struct rxrpc_call *call = (struct rxrpc_call *) _call;

	_enter("{%d}", call->debug_id);

	if (call->state >= RXRPC_CALL_COMPLETE)
		return;

	read_lock_bh(&call->state_lock);
	if (call->state < RXRPC_CALL_COMPLETE &&
	    !test_and_set_bit(RXRPC_CALL_ACK, &call->events))
		rxrpc_queue_call(call);
	read_unlock_bh(&call->state_lock);
}