xref: /openbmc/linux/net/rxrpc/call_object.c (revision 9aab6601)
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_ACCEPTING]		= "SvAccept",
27 	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
28 	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
29 	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
30 	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
31 	[RXRPC_CALL_COMPLETE]			= "Complete",
32 };
33 
34 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
35 	[RXRPC_CALL_SUCCEEDED]			= "Complete",
36 	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
37 	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
38 	[RXRPC_CALL_LOCAL_ERROR]		= "LocError",
39 	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
40 };
41 
42 struct kmem_cache *rxrpc_call_jar;
43 
44 static void rxrpc_call_timer_expired(struct timer_list *t)
45 {
46 	struct rxrpc_call *call = from_timer(call, t, timer);
47 
48 	_enter("%d", call->debug_id);
49 
50 	if (call->state < RXRPC_CALL_COMPLETE) {
51 		trace_rxrpc_timer(call, rxrpc_timer_expired, jiffies);
52 		rxrpc_queue_call(call);
53 	}
54 }
55 
56 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
57 
58 /*
59  * find an extant server call
60  * - called in process context with IRQs enabled
61  */
62 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
63 					      unsigned long user_call_ID)
64 {
65 	struct rxrpc_call *call;
66 	struct rb_node *p;
67 
68 	_enter("%p,%lx", rx, user_call_ID);
69 
70 	read_lock(&rx->call_lock);
71 
72 	p = rx->calls.rb_node;
73 	while (p) {
74 		call = rb_entry(p, struct rxrpc_call, sock_node);
75 
76 		if (user_call_ID < call->user_call_ID)
77 			p = p->rb_left;
78 		else if (user_call_ID > call->user_call_ID)
79 			p = p->rb_right;
80 		else
81 			goto found_extant_call;
82 	}
83 
84 	read_unlock(&rx->call_lock);
85 	_leave(" = NULL");
86 	return NULL;
87 
88 found_extant_call:
89 	rxrpc_get_call(call, rxrpc_call_got);
90 	read_unlock(&rx->call_lock);
91 	_leave(" = %p [%d]", call, atomic_read(&call->usage));
92 	return call;
93 }
94 
95 /*
96  * allocate a new call
97  */
98 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
99 				    unsigned int debug_id)
100 {
101 	struct rxrpc_call *call;
102 	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
103 
104 	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
105 	if (!call)
106 		return NULL;
107 
108 	call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
109 				    sizeof(struct sk_buff *),
110 				    gfp);
111 	if (!call->rxtx_buffer)
112 		goto nomem;
113 
114 	call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
115 	if (!call->rxtx_annotations)
116 		goto nomem_2;
117 
118 	mutex_init(&call->user_mutex);
119 
120 	/* Prevent lockdep reporting a deadlock false positive between the afs
121 	 * filesystem and sys_sendmsg() via the mmap sem.
122 	 */
123 	if (rx->sk.sk_kern_sock)
124 		lockdep_set_class(&call->user_mutex,
125 				  &rxrpc_call_user_mutex_lock_class_key);
126 
127 	timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
128 	INIT_WORK(&call->processor, &rxrpc_process_call);
129 	INIT_LIST_HEAD(&call->link);
130 	INIT_LIST_HEAD(&call->chan_wait_link);
131 	INIT_LIST_HEAD(&call->accept_link);
132 	INIT_LIST_HEAD(&call->recvmsg_link);
133 	INIT_LIST_HEAD(&call->sock_link);
134 	init_waitqueue_head(&call->waitq);
135 	spin_lock_init(&call->lock);
136 	spin_lock_init(&call->notify_lock);
137 	spin_lock_init(&call->input_lock);
138 	rwlock_init(&call->state_lock);
139 	atomic_set(&call->usage, 1);
140 	call->debug_id = debug_id;
141 	call->tx_total_len = -1;
142 	call->next_rx_timo = 20 * HZ;
143 	call->next_req_timo = 1 * HZ;
144 
145 	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
146 
147 	/* Leave space in the ring to handle a maxed-out jumbo packet */
148 	call->rx_winsize = rxrpc_rx_window_size;
149 	call->tx_winsize = 16;
150 	call->rx_expect_next = 1;
151 
152 	call->cong_cwnd = 2;
153 	call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
154 
155 	call->rxnet = rxnet;
156 	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
157 	atomic_inc(&rxnet->nr_calls);
158 	return call;
159 
160 nomem_2:
161 	kfree(call->rxtx_buffer);
162 nomem:
163 	kmem_cache_free(rxrpc_call_jar, call);
164 	return NULL;
165 }
166 
167 /*
168  * Allocate a new client call.
169  */
170 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
171 						  struct sockaddr_rxrpc *srx,
172 						  gfp_t gfp,
173 						  unsigned int debug_id)
174 {
175 	struct rxrpc_call *call;
176 	ktime_t now;
177 
178 	_enter("");
179 
180 	call = rxrpc_alloc_call(rx, gfp, debug_id);
181 	if (!call)
182 		return ERR_PTR(-ENOMEM);
183 	call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
184 	call->service_id = srx->srx_service;
185 	call->tx_phase = true;
186 	now = ktime_get_real();
187 	call->acks_latest_ts = now;
188 	call->cong_tstamp = now;
189 
190 	_leave(" = %p", call);
191 	return call;
192 }
193 
194 /*
195  * Initiate the call ack/resend/expiry timer.
196  */
197 static void rxrpc_start_call_timer(struct rxrpc_call *call)
198 {
199 	unsigned long now = jiffies;
200 	unsigned long j = now + MAX_JIFFY_OFFSET;
201 
202 	call->ack_at = j;
203 	call->ack_lost_at = j;
204 	call->resend_at = j;
205 	call->ping_at = j;
206 	call->expect_rx_by = j;
207 	call->expect_req_by = j;
208 	call->expect_term_by = j;
209 	call->timer.expires = now;
210 }
211 
212 /*
213  * Set up a call for the given parameters.
214  * - Called with the socket lock held, which it must release.
215  * - If it returns a call, the call's lock will need releasing by the caller.
216  */
217 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
218 					 struct rxrpc_conn_parameters *cp,
219 					 struct sockaddr_rxrpc *srx,
220 					 struct rxrpc_call_params *p,
221 					 gfp_t gfp,
222 					 unsigned int debug_id)
223 	__releases(&rx->sk.sk_lock.slock)
224 	__acquires(&call->user_mutex)
225 {
226 	struct rxrpc_call *call, *xcall;
227 	struct rxrpc_net *rxnet;
228 	struct rb_node *parent, **pp;
229 	const void *here = __builtin_return_address(0);
230 	int ret;
231 
232 	_enter("%p,%lx", rx, p->user_call_ID);
233 
234 	call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
235 	if (IS_ERR(call)) {
236 		release_sock(&rx->sk);
237 		_leave(" = %ld", PTR_ERR(call));
238 		return call;
239 	}
240 
241 	call->interruptibility = p->interruptibility;
242 	call->tx_total_len = p->tx_total_len;
243 	trace_rxrpc_call(call->debug_id, rxrpc_call_new_client,
244 			 atomic_read(&call->usage),
245 			 here, (const void *)p->user_call_ID);
246 
247 	/* We need to protect a partially set up call against the user as we
248 	 * will be acting outside the socket lock.
249 	 */
250 	mutex_lock(&call->user_mutex);
251 
252 	/* Publish the call, even though it is incompletely set up as yet */
253 	write_lock(&rx->call_lock);
254 
255 	pp = &rx->calls.rb_node;
256 	parent = NULL;
257 	while (*pp) {
258 		parent = *pp;
259 		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
260 
261 		if (p->user_call_ID < xcall->user_call_ID)
262 			pp = &(*pp)->rb_left;
263 		else if (p->user_call_ID > xcall->user_call_ID)
264 			pp = &(*pp)->rb_right;
265 		else
266 			goto error_dup_user_ID;
267 	}
268 
269 	rcu_assign_pointer(call->socket, rx);
270 	call->user_call_ID = p->user_call_ID;
271 	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
272 	rxrpc_get_call(call, rxrpc_call_got_userid);
273 	rb_link_node(&call->sock_node, parent, pp);
274 	rb_insert_color(&call->sock_node, &rx->calls);
275 	list_add(&call->sock_link, &rx->sock_calls);
276 
277 	write_unlock(&rx->call_lock);
278 
279 	rxnet = call->rxnet;
280 	write_lock(&rxnet->call_lock);
281 	list_add_tail(&call->link, &rxnet->calls);
282 	write_unlock(&rxnet->call_lock);
283 
284 	/* From this point on, the call is protected by its own lock. */
285 	release_sock(&rx->sk);
286 
287 	/* Set up or get a connection record and set the protocol parameters,
288 	 * including channel number and call ID.
289 	 */
290 	ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
291 	if (ret < 0)
292 		goto error_attached_to_socket;
293 
294 	trace_rxrpc_call(call->debug_id, rxrpc_call_connected,
295 			 atomic_read(&call->usage), here, NULL);
296 
297 	rxrpc_start_call_timer(call);
298 
299 	_net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
300 
301 	_leave(" = %p [new]", call);
302 	return call;
303 
304 	/* We unexpectedly found the user ID in the list after taking
305 	 * the call_lock.  This shouldn't happen unless the user races
306 	 * with itself and tries to add the same user ID twice at the
307 	 * same time in different threads.
308 	 */
309 error_dup_user_ID:
310 	write_unlock(&rx->call_lock);
311 	release_sock(&rx->sk);
312 	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
313 				    RX_CALL_DEAD, -EEXIST);
314 	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
315 			 atomic_read(&call->usage), here, ERR_PTR(-EEXIST));
316 	rxrpc_release_call(rx, call);
317 	mutex_unlock(&call->user_mutex);
318 	rxrpc_put_call(call, rxrpc_call_put);
319 	_leave(" = -EEXIST");
320 	return ERR_PTR(-EEXIST);
321 
322 	/* We got an error, but the call is attached to the socket and is in
323 	 * need of release.  However, we might now race with recvmsg() when
324 	 * completing the call queues it.  Return 0 from sys_sendmsg() and
325 	 * leave the error to recvmsg() to deal with.
326 	 */
327 error_attached_to_socket:
328 	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
329 			 atomic_read(&call->usage), here, ERR_PTR(ret));
330 	set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
331 	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
332 				    RX_CALL_DEAD, ret);
333 	_leave(" = c=%08x [err]", call->debug_id);
334 	return call;
335 }
336 
337 /*
338  * Set up an incoming call.  call->conn points to the connection.
339  * This is called in BH context and isn't allowed to fail.
340  */
341 void rxrpc_incoming_call(struct rxrpc_sock *rx,
342 			 struct rxrpc_call *call,
343 			 struct sk_buff *skb)
344 {
345 	struct rxrpc_connection *conn = call->conn;
346 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
347 	u32 chan;
348 
349 	_enter(",%d", call->conn->debug_id);
350 
351 	rcu_assign_pointer(call->socket, rx);
352 	call->call_id		= sp->hdr.callNumber;
353 	call->service_id	= sp->hdr.serviceId;
354 	call->cid		= sp->hdr.cid;
355 	call->state		= RXRPC_CALL_SERVER_ACCEPTING;
356 	if (sp->hdr.securityIndex > 0)
357 		call->state	= RXRPC_CALL_SERVER_SECURING;
358 	call->cong_tstamp	= skb->tstamp;
359 
360 	/* Set the channel for this call.  We don't get channel_lock as we're
361 	 * only defending against the data_ready handler (which we're called
362 	 * from) and the RESPONSE packet parser (which is only really
363 	 * interested in call_counter and can cope with a disagreement with the
364 	 * call pointer).
365 	 */
366 	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
367 	conn->channels[chan].call_counter = call->call_id;
368 	conn->channels[chan].call_id = call->call_id;
369 	rcu_assign_pointer(conn->channels[chan].call, call);
370 
371 	spin_lock(&conn->params.peer->lock);
372 	hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets);
373 	spin_unlock(&conn->params.peer->lock);
374 
375 	_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
376 
377 	rxrpc_start_call_timer(call);
378 	_leave("");
379 }
380 
381 /*
382  * Queue a call's work processor, getting a ref to pass to the work queue.
383  */
384 bool rxrpc_queue_call(struct rxrpc_call *call)
385 {
386 	const void *here = __builtin_return_address(0);
387 	int n = atomic_fetch_add_unless(&call->usage, 1, 0);
388 	if (n == 0)
389 		return false;
390 	if (rxrpc_queue_work(&call->processor))
391 		trace_rxrpc_call(call->debug_id, rxrpc_call_queued, n + 1,
392 				 here, NULL);
393 	else
394 		rxrpc_put_call(call, rxrpc_call_put_noqueue);
395 	return true;
396 }
397 
398 /*
399  * Queue a call's work processor, passing the callers ref to the work queue.
400  */
401 bool __rxrpc_queue_call(struct rxrpc_call *call)
402 {
403 	const void *here = __builtin_return_address(0);
404 	int n = atomic_read(&call->usage);
405 	ASSERTCMP(n, >=, 1);
406 	if (rxrpc_queue_work(&call->processor))
407 		trace_rxrpc_call(call->debug_id, rxrpc_call_queued_ref, n,
408 				 here, NULL);
409 	else
410 		rxrpc_put_call(call, rxrpc_call_put_noqueue);
411 	return true;
412 }
413 
414 /*
415  * Note the re-emergence of a call.
416  */
417 void rxrpc_see_call(struct rxrpc_call *call)
418 {
419 	const void *here = __builtin_return_address(0);
420 	if (call) {
421 		int n = atomic_read(&call->usage);
422 
423 		trace_rxrpc_call(call->debug_id, rxrpc_call_seen, n,
424 				 here, NULL);
425 	}
426 }
427 
428 /*
429  * Note the addition of a ref on a call.
430  */
431 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
432 {
433 	const void *here = __builtin_return_address(0);
434 	int n = atomic_inc_return(&call->usage);
435 
436 	trace_rxrpc_call(call->debug_id, op, n, here, NULL);
437 }
438 
439 /*
440  * Clean up the RxTx skb ring.
441  */
442 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
443 {
444 	int i;
445 
446 	for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
447 		rxrpc_free_skb(call->rxtx_buffer[i], rxrpc_skb_cleaned);
448 		call->rxtx_buffer[i] = NULL;
449 	}
450 }
451 
452 /*
453  * Detach a call from its owning socket.
454  */
455 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
456 {
457 	const void *here = __builtin_return_address(0);
458 	struct rxrpc_connection *conn = call->conn;
459 	bool put = false;
460 
461 	_enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
462 
463 	trace_rxrpc_call(call->debug_id, rxrpc_call_release,
464 			 atomic_read(&call->usage),
465 			 here, (const void *)call->flags);
466 
467 	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
468 
469 	spin_lock_bh(&call->lock);
470 	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
471 		BUG();
472 	spin_unlock_bh(&call->lock);
473 
474 	del_timer_sync(&call->timer);
475 
476 	/* Make sure we don't get any more notifications */
477 	write_lock_bh(&rx->recvmsg_lock);
478 
479 	if (!list_empty(&call->recvmsg_link)) {
480 		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
481 		       call, call->events, call->flags);
482 		list_del(&call->recvmsg_link);
483 		put = true;
484 	}
485 
486 	/* list_empty() must return false in rxrpc_notify_socket() */
487 	call->recvmsg_link.next = NULL;
488 	call->recvmsg_link.prev = NULL;
489 
490 	write_unlock_bh(&rx->recvmsg_lock);
491 	if (put)
492 		rxrpc_put_call(call, rxrpc_call_put);
493 
494 	write_lock(&rx->call_lock);
495 
496 	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
497 		rb_erase(&call->sock_node, &rx->calls);
498 		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
499 		rxrpc_put_call(call, rxrpc_call_put_userid);
500 	}
501 
502 	list_del(&call->sock_link);
503 	write_unlock(&rx->call_lock);
504 
505 	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
506 
507 	if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
508 		rxrpc_disconnect_call(call);
509 	if (call->security)
510 		call->security->free_call_crypto(call);
511 
512 	rxrpc_cleanup_ring(call);
513 	_leave("");
514 }
515 
516 /*
517  * release all the calls associated with a socket
518  */
519 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
520 {
521 	struct rxrpc_call *call;
522 
523 	_enter("%p", rx);
524 
525 	while (!list_empty(&rx->to_be_accepted)) {
526 		call = list_entry(rx->to_be_accepted.next,
527 				  struct rxrpc_call, accept_link);
528 		list_del(&call->accept_link);
529 		rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
530 		rxrpc_put_call(call, rxrpc_call_put);
531 	}
532 
533 	while (!list_empty(&rx->sock_calls)) {
534 		call = list_entry(rx->sock_calls.next,
535 				  struct rxrpc_call, sock_link);
536 		rxrpc_get_call(call, rxrpc_call_got);
537 		rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
538 		rxrpc_send_abort_packet(call);
539 		rxrpc_release_call(rx, call);
540 		rxrpc_put_call(call, rxrpc_call_put);
541 	}
542 
543 	_leave("");
544 }
545 
546 /*
547  * release a call
548  */
549 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
550 {
551 	struct rxrpc_net *rxnet = call->rxnet;
552 	const void *here = __builtin_return_address(0);
553 	unsigned int debug_id = call->debug_id;
554 	int n;
555 
556 	ASSERT(call != NULL);
557 
558 	n = atomic_dec_return(&call->usage);
559 	trace_rxrpc_call(debug_id, op, n, here, NULL);
560 	ASSERTCMP(n, >=, 0);
561 	if (n == 0) {
562 		_debug("call %d dead", call->debug_id);
563 		ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
564 
565 		if (!list_empty(&call->link)) {
566 			write_lock(&rxnet->call_lock);
567 			list_del_init(&call->link);
568 			write_unlock(&rxnet->call_lock);
569 		}
570 
571 		rxrpc_cleanup_call(call);
572 	}
573 }
574 
575 /*
576  * Final call destruction - but must be done in process context.
577  */
578 static void rxrpc_destroy_call(struct work_struct *work)
579 {
580 	struct rxrpc_call *call = container_of(work, struct rxrpc_call, processor);
581 	struct rxrpc_net *rxnet = call->rxnet;
582 
583 	rxrpc_put_connection(call->conn);
584 	rxrpc_put_peer(call->peer);
585 	kfree(call->rxtx_buffer);
586 	kfree(call->rxtx_annotations);
587 	kmem_cache_free(rxrpc_call_jar, call);
588 	if (atomic_dec_and_test(&rxnet->nr_calls))
589 		wake_up_var(&rxnet->nr_calls);
590 }
591 
592 /*
593  * Final call destruction under RCU.
594  */
595 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
596 {
597 	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
598 
599 	if (in_softirq()) {
600 		INIT_WORK(&call->processor, rxrpc_destroy_call);
601 		if (!rxrpc_queue_work(&call->processor))
602 			BUG();
603 	} else {
604 		rxrpc_destroy_call(&call->processor);
605 	}
606 }
607 
608 /*
609  * clean up a call
610  */
611 void rxrpc_cleanup_call(struct rxrpc_call *call)
612 {
613 	_net("DESTROY CALL %d", call->debug_id);
614 
615 	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
616 
617 	del_timer_sync(&call->timer);
618 
619 	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
620 	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
621 
622 	rxrpc_cleanup_ring(call);
623 	rxrpc_free_skb(call->tx_pending, rxrpc_skb_cleaned);
624 
625 	call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
626 }
627 
628 /*
629  * Make sure that all calls are gone from a network namespace.  To reach this
630  * point, any open UDP sockets in that namespace must have been closed, so any
631  * outstanding calls cannot be doing I/O.
632  */
633 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
634 {
635 	struct rxrpc_call *call;
636 
637 	_enter("");
638 
639 	if (!list_empty(&rxnet->calls)) {
640 		write_lock(&rxnet->call_lock);
641 
642 		while (!list_empty(&rxnet->calls)) {
643 			call = list_entry(rxnet->calls.next,
644 					  struct rxrpc_call, link);
645 			_debug("Zapping call %p", call);
646 
647 			rxrpc_see_call(call);
648 			list_del_init(&call->link);
649 
650 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
651 			       call, atomic_read(&call->usage),
652 			       rxrpc_call_states[call->state],
653 			       call->flags, call->events);
654 
655 			write_unlock(&rxnet->call_lock);
656 			cond_resched();
657 			write_lock(&rxnet->call_lock);
658 		}
659 
660 		write_unlock(&rxnet->call_lock);
661 	}
662 
663 	atomic_dec(&rxnet->nr_calls);
664 	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
665 }
666