xref: /linux/net/rxrpc/call_object.c (revision 6af91e3d2cfc8bb579b1aa2d22cd91f8c34acdf6)
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 DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000);
44 static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000);
45 
46 void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what)
47 {
48 	struct rxrpc_local *local = call->local;
49 	bool busy;
50 
51 	if (!test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) {
52 		spin_lock_bh(&local->lock);
53 		busy = !list_empty(&call->attend_link);
54 		trace_rxrpc_poke_call(call, busy, what);
55 		if (!busy && !rxrpc_try_get_call(call, rxrpc_call_get_poke))
56 			busy = true;
57 		if (!busy) {
58 			list_add_tail(&call->attend_link, &local->call_attend_q);
59 		}
60 		spin_unlock_bh(&local->lock);
61 		if (!busy)
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 (!__rxrpc_call_is_complete(call)) {
73 		trace_rxrpc_timer_expired(call);
74 		rxrpc_poke_call(call, rxrpc_call_poke_timer);
75 	}
76 }
77 
78 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
79 
80 static void rxrpc_destroy_call(struct work_struct *);
81 
82 /*
83  * find an extant server call
84  * - called in process context with IRQs enabled
85  */
86 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
87 					      unsigned long user_call_ID)
88 {
89 	struct rxrpc_call *call;
90 	struct rb_node *p;
91 
92 	_enter("%p,%lx", rx, user_call_ID);
93 
94 	read_lock(&rx->call_lock);
95 
96 	p = rx->calls.rb_node;
97 	while (p) {
98 		call = rb_entry(p, struct rxrpc_call, sock_node);
99 
100 		if (user_call_ID < call->user_call_ID)
101 			p = p->rb_left;
102 		else if (user_call_ID > call->user_call_ID)
103 			p = p->rb_right;
104 		else
105 			goto found_extant_call;
106 	}
107 
108 	read_unlock(&rx->call_lock);
109 	_leave(" = NULL");
110 	return NULL;
111 
112 found_extant_call:
113 	rxrpc_get_call(call, rxrpc_call_get_sendmsg);
114 	read_unlock(&rx->call_lock);
115 	_leave(" = %p [%d]", call, refcount_read(&call->ref));
116 	return call;
117 }
118 
119 /*
120  * allocate a new call
121  */
122 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
123 				    unsigned int debug_id)
124 {
125 	struct rxrpc_call *call;
126 	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
127 
128 	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
129 	if (!call)
130 		return NULL;
131 
132 	mutex_init(&call->user_mutex);
133 
134 	/* Prevent lockdep reporting a deadlock false positive between the afs
135 	 * filesystem and sys_sendmsg() via the mmap sem.
136 	 */
137 	if (rx->sk.sk_kern_sock)
138 		lockdep_set_class(&call->user_mutex,
139 				  &rxrpc_call_user_mutex_lock_class_key);
140 
141 	timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
142 	INIT_WORK(&call->destroyer, rxrpc_destroy_call);
143 	INIT_LIST_HEAD(&call->link);
144 	INIT_LIST_HEAD(&call->wait_link);
145 	INIT_LIST_HEAD(&call->accept_link);
146 	INIT_LIST_HEAD(&call->recvmsg_link);
147 	INIT_LIST_HEAD(&call->sock_link);
148 	INIT_LIST_HEAD(&call->attend_link);
149 	INIT_LIST_HEAD(&call->tx_sendmsg);
150 	INIT_LIST_HEAD(&call->tx_buffer);
151 	skb_queue_head_init(&call->recvmsg_queue);
152 	skb_queue_head_init(&call->rx_oos_queue);
153 	init_waitqueue_head(&call->waitq);
154 	spin_lock_init(&call->notify_lock);
155 	spin_lock_init(&call->tx_lock);
156 	refcount_set(&call->ref, 1);
157 	call->debug_id		= debug_id;
158 	call->tx_total_len	= -1;
159 	call->next_rx_timo	= 20 * HZ;
160 	call->next_req_timo	= 1 * HZ;
161 	call->ackr_window	= 1;
162 	call->ackr_wtop		= 1;
163 	call->delay_ack_at	= KTIME_MAX;
164 	call->ack_lost_at	= KTIME_MAX;
165 	call->resend_at		= KTIME_MAX;
166 	call->ping_at		= KTIME_MAX;
167 	call->keepalive_at	= KTIME_MAX;
168 	call->expect_rx_by	= KTIME_MAX;
169 	call->expect_req_by	= KTIME_MAX;
170 	call->expect_term_by	= KTIME_MAX;
171 
172 	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
173 
174 	call->rx_winsize = rxrpc_rx_window_size;
175 	call->tx_winsize = 16;
176 
177 	call->cong_cwnd = RXRPC_MIN_CWND;
178 	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
179 
180 	call->rxnet = rxnet;
181 	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
182 	atomic_inc(&rxnet->nr_calls);
183 	return call;
184 }
185 
186 /*
187  * Allocate a new client call.
188  */
189 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
190 						  struct rxrpc_conn_parameters *cp,
191 						  struct rxrpc_call_params *p,
192 						  gfp_t gfp,
193 						  unsigned int debug_id)
194 {
195 	struct rxrpc_call *call;
196 	ktime_t now;
197 	int ret;
198 
199 	_enter("");
200 
201 	call = rxrpc_alloc_call(rx, gfp, debug_id);
202 	if (!call)
203 		return ERR_PTR(-ENOMEM);
204 	now = ktime_get_real();
205 	call->acks_latest_ts	= now;
206 	call->cong_tstamp	= now;
207 	call->dest_srx		= cp->peer->srx;
208 	call->dest_srx.srx_service = cp->service_id;
209 	call->interruptibility	= p->interruptibility;
210 	call->tx_total_len	= p->tx_total_len;
211 	call->key		= key_get(cp->key);
212 	call->peer		= rxrpc_get_peer(cp->peer, rxrpc_peer_get_call);
213 	call->local		= rxrpc_get_local(cp->local, rxrpc_local_get_call);
214 	call->security_level	= cp->security_level;
215 	if (p->kernel)
216 		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
217 	if (cp->upgrade)
218 		__set_bit(RXRPC_CALL_UPGRADE, &call->flags);
219 	if (cp->exclusive)
220 		__set_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
221 
222 	if (p->timeouts.normal)
223 		call->next_rx_timo = min(p->timeouts.normal, 1);
224 	if (p->timeouts.idle)
225 		call->next_req_timo = min(p->timeouts.idle, 1);
226 	if (p->timeouts.hard)
227 		call->hard_timo = p->timeouts.hard;
228 
229 	ret = rxrpc_init_client_call_security(call);
230 	if (ret < 0) {
231 		rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret);
232 		rxrpc_put_call(call, rxrpc_call_put_discard_error);
233 		return ERR_PTR(ret);
234 	}
235 
236 	rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_CONN);
237 
238 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
239 			 p->user_call_ID, rxrpc_call_new_client);
240 
241 	_leave(" = %p", call);
242 	return call;
243 }
244 
245 /*
246  * Initiate the call ack/resend/expiry timer.
247  */
248 void rxrpc_start_call_timer(struct rxrpc_call *call)
249 {
250 	if (call->hard_timo) {
251 		ktime_t delay = ms_to_ktime(call->hard_timo * 1000);
252 
253 		call->expect_term_by = ktime_add(ktime_get_real(), delay);
254 		trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
255 	}
256 	call->timer.expires = jiffies;
257 }
258 
259 /*
260  * Wait for a call slot to become available.
261  */
262 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
263 {
264 	struct semaphore *limiter = &rxrpc_call_limiter;
265 
266 	if (p->kernel)
267 		limiter = &rxrpc_kernel_call_limiter;
268 	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
269 		down(limiter);
270 		return limiter;
271 	}
272 	return down_interruptible(limiter) < 0 ? NULL : limiter;
273 }
274 
275 /*
276  * Release a call slot.
277  */
278 static void rxrpc_put_call_slot(struct rxrpc_call *call)
279 {
280 	struct semaphore *limiter = &rxrpc_call_limiter;
281 
282 	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
283 		limiter = &rxrpc_kernel_call_limiter;
284 	up(limiter);
285 }
286 
287 /*
288  * Start the process of connecting a call.  We obtain a peer and a connection
289  * bundle, but the actual association of a call with a connection is offloaded
290  * to the I/O thread to simplify locking.
291  */
292 static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
293 {
294 	struct rxrpc_local *local = call->local;
295 	int ret = -ENOMEM;
296 
297 	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
298 
299 	ret = rxrpc_look_up_bundle(call, gfp);
300 	if (ret < 0)
301 		goto error;
302 
303 	trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
304 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
305 	spin_lock(&local->client_call_lock);
306 	list_add_tail(&call->wait_link, &local->new_client_calls);
307 	spin_unlock(&local->client_call_lock);
308 	rxrpc_wake_up_io_thread(local);
309 	return 0;
310 
311 error:
312 	__set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
313 	return ret;
314 }
315 
316 /*
317  * Set up a call for the given parameters.
318  * - Called with the socket lock held, which it must release.
319  * - If it returns a call, the call's lock will need releasing by the caller.
320  */
321 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
322 					 struct rxrpc_conn_parameters *cp,
323 					 struct rxrpc_call_params *p,
324 					 gfp_t gfp,
325 					 unsigned int debug_id)
326 	__releases(&rx->sk.sk_lock.slock)
327 	__acquires(&call->user_mutex)
328 {
329 	struct rxrpc_call *call, *xcall;
330 	struct rxrpc_net *rxnet;
331 	struct semaphore *limiter;
332 	struct rb_node *parent, **pp;
333 	int ret;
334 
335 	_enter("%p,%lx", rx, p->user_call_ID);
336 
337 	if (WARN_ON_ONCE(!cp->peer)) {
338 		release_sock(&rx->sk);
339 		return ERR_PTR(-EIO);
340 	}
341 
342 	limiter = rxrpc_get_call_slot(p, gfp);
343 	if (!limiter) {
344 		release_sock(&rx->sk);
345 		return ERR_PTR(-ERESTARTSYS);
346 	}
347 
348 	call = rxrpc_alloc_client_call(rx, cp, p, gfp, debug_id);
349 	if (IS_ERR(call)) {
350 		release_sock(&rx->sk);
351 		up(limiter);
352 		_leave(" = %ld", PTR_ERR(call));
353 		return call;
354 	}
355 
356 	/* We need to protect a partially set up call against the user as we
357 	 * will be acting outside the socket lock.
358 	 */
359 	mutex_lock(&call->user_mutex);
360 
361 	/* Publish the call, even though it is incompletely set up as yet */
362 	write_lock(&rx->call_lock);
363 
364 	pp = &rx->calls.rb_node;
365 	parent = NULL;
366 	while (*pp) {
367 		parent = *pp;
368 		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
369 
370 		if (p->user_call_ID < xcall->user_call_ID)
371 			pp = &(*pp)->rb_left;
372 		else if (p->user_call_ID > xcall->user_call_ID)
373 			pp = &(*pp)->rb_right;
374 		else
375 			goto error_dup_user_ID;
376 	}
377 
378 	rcu_assign_pointer(call->socket, rx);
379 	call->user_call_ID = p->user_call_ID;
380 	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
381 	rxrpc_get_call(call, rxrpc_call_get_userid);
382 	rb_link_node(&call->sock_node, parent, pp);
383 	rb_insert_color(&call->sock_node, &rx->calls);
384 	list_add(&call->sock_link, &rx->sock_calls);
385 
386 	write_unlock(&rx->call_lock);
387 
388 	rxnet = call->rxnet;
389 	spin_lock(&rxnet->call_lock);
390 	list_add_tail_rcu(&call->link, &rxnet->calls);
391 	spin_unlock(&rxnet->call_lock);
392 
393 	/* From this point on, the call is protected by its own lock. */
394 	release_sock(&rx->sk);
395 
396 	/* Set up or get a connection record and set the protocol parameters,
397 	 * including channel number and call ID.
398 	 */
399 	ret = rxrpc_connect_call(call, gfp);
400 	if (ret < 0)
401 		goto error_attached_to_socket;
402 
403 	_leave(" = %p [new]", call);
404 	return call;
405 
406 	/* We unexpectedly found the user ID in the list after taking
407 	 * the call_lock.  This shouldn't happen unless the user races
408 	 * with itself and tries to add the same user ID twice at the
409 	 * same time in different threads.
410 	 */
411 error_dup_user_ID:
412 	write_unlock(&rx->call_lock);
413 	release_sock(&rx->sk);
414 	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
415 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
416 			 rxrpc_call_see_userid_exists);
417 	mutex_unlock(&call->user_mutex);
418 	rxrpc_put_call(call, rxrpc_call_put_userid_exists);
419 	_leave(" = -EEXIST");
420 	return ERR_PTR(-EEXIST);
421 
422 	/* We got an error, but the call is attached to the socket and is in
423 	 * need of release.  However, we might now race with recvmsg() when it
424 	 * completion notifies the socket.  Return 0 from sys_sendmsg() and
425 	 * leave the error to recvmsg() to deal with.
426 	 */
427 error_attached_to_socket:
428 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
429 			 rxrpc_call_see_connect_failed);
430 	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
431 	_leave(" = c=%08x [err]", call->debug_id);
432 	return call;
433 }
434 
435 /*
436  * Set up an incoming call.  call->conn points to the connection.
437  * This is called in BH context and isn't allowed to fail.
438  */
439 void rxrpc_incoming_call(struct rxrpc_sock *rx,
440 			 struct rxrpc_call *call,
441 			 struct sk_buff *skb)
442 {
443 	struct rxrpc_connection *conn = call->conn;
444 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
445 	u32 chan;
446 
447 	_enter(",%d", call->conn->debug_id);
448 
449 	rcu_assign_pointer(call->socket, rx);
450 	call->call_id		= sp->hdr.callNumber;
451 	call->dest_srx.srx_service = sp->hdr.serviceId;
452 	call->cid		= sp->hdr.cid;
453 	call->cong_tstamp	= skb->tstamp;
454 
455 	__set_bit(RXRPC_CALL_EXPOSED, &call->flags);
456 	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
457 
458 	spin_lock(&conn->state_lock);
459 
460 	switch (conn->state) {
461 	case RXRPC_CONN_SERVICE_UNSECURED:
462 	case RXRPC_CONN_SERVICE_CHALLENGING:
463 		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
464 		break;
465 	case RXRPC_CONN_SERVICE:
466 		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
467 		break;
468 
469 	case RXRPC_CONN_ABORTED:
470 		rxrpc_set_call_completion(call, conn->completion,
471 					  conn->abort_code, conn->error);
472 		break;
473 	default:
474 		BUG();
475 	}
476 
477 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
478 
479 	/* Set the channel for this call.  We don't get channel_lock as we're
480 	 * only defending against the data_ready handler (which we're called
481 	 * from) and the RESPONSE packet parser (which is only really
482 	 * interested in call_counter and can cope with a disagreement with the
483 	 * call pointer).
484 	 */
485 	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
486 	conn->channels[chan].call_counter = call->call_id;
487 	conn->channels[chan].call_id = call->call_id;
488 	conn->channels[chan].call = call;
489 	spin_unlock(&conn->state_lock);
490 
491 	spin_lock(&conn->peer->lock);
492 	hlist_add_head(&call->error_link, &conn->peer->error_targets);
493 	spin_unlock(&conn->peer->lock);
494 
495 	rxrpc_start_call_timer(call);
496 	_leave("");
497 }
498 
499 /*
500  * Note the re-emergence of a call.
501  */
502 void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
503 {
504 	if (call) {
505 		int r = refcount_read(&call->ref);
506 
507 		trace_rxrpc_call(call->debug_id, r, 0, why);
508 	}
509 }
510 
511 struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call,
512 				      enum rxrpc_call_trace why)
513 {
514 	int r;
515 
516 	if (!call || !__refcount_inc_not_zero(&call->ref, &r))
517 		return NULL;
518 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
519 	return call;
520 }
521 
522 /*
523  * Note the addition of a ref on a call.
524  */
525 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
526 {
527 	int r;
528 
529 	__refcount_inc(&call->ref, &r);
530 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
531 }
532 
533 /*
534  * Clean up the Rx skb ring.
535  */
536 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
537 {
538 	rxrpc_purge_queue(&call->recvmsg_queue);
539 	rxrpc_purge_queue(&call->rx_oos_queue);
540 }
541 
542 /*
543  * Detach a call from its owning socket.
544  */
545 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
546 {
547 	struct rxrpc_connection *conn = call->conn;
548 	bool put = false, putu = false;
549 
550 	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
551 
552 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
553 			 call->flags, rxrpc_call_see_release);
554 
555 	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
556 		BUG();
557 
558 	rxrpc_put_call_slot(call);
559 
560 	/* Make sure we don't get any more notifications */
561 	spin_lock(&rx->recvmsg_lock);
562 
563 	if (!list_empty(&call->recvmsg_link)) {
564 		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
565 		       call, call->events, call->flags);
566 		list_del(&call->recvmsg_link);
567 		put = true;
568 	}
569 
570 	/* list_empty() must return false in rxrpc_notify_socket() */
571 	call->recvmsg_link.next = NULL;
572 	call->recvmsg_link.prev = NULL;
573 
574 	spin_unlock(&rx->recvmsg_lock);
575 	if (put)
576 		rxrpc_put_call(call, rxrpc_call_put_unnotify);
577 
578 	write_lock(&rx->call_lock);
579 
580 	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
581 		rb_erase(&call->sock_node, &rx->calls);
582 		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
583 		putu = true;
584 	}
585 
586 	list_del(&call->sock_link);
587 	write_unlock(&rx->call_lock);
588 
589 	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
590 
591 	if (putu)
592 		rxrpc_put_call(call, rxrpc_call_put_userid);
593 
594 	_leave("");
595 }
596 
597 /*
598  * release all the calls associated with a socket
599  */
600 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
601 {
602 	struct rxrpc_call *call;
603 
604 	_enter("%p", rx);
605 
606 	while (!list_empty(&rx->to_be_accepted)) {
607 		call = list_entry(rx->to_be_accepted.next,
608 				  struct rxrpc_call, accept_link);
609 		list_del(&call->accept_link);
610 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
611 				    rxrpc_abort_call_sock_release_tba);
612 		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
613 	}
614 
615 	while (!list_empty(&rx->sock_calls)) {
616 		call = list_entry(rx->sock_calls.next,
617 				  struct rxrpc_call, sock_link);
618 		rxrpc_get_call(call, rxrpc_call_get_release_sock);
619 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
620 				    rxrpc_abort_call_sock_release);
621 		rxrpc_release_call(rx, call);
622 		rxrpc_put_call(call, rxrpc_call_put_release_sock);
623 	}
624 
625 	_leave("");
626 }
627 
628 /*
629  * release a call
630  */
631 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
632 {
633 	struct rxrpc_net *rxnet = call->rxnet;
634 	unsigned int debug_id = call->debug_id;
635 	bool dead;
636 	int r;
637 
638 	ASSERT(call != NULL);
639 
640 	dead = __refcount_dec_and_test(&call->ref, &r);
641 	trace_rxrpc_call(debug_id, r - 1, 0, why);
642 	if (dead) {
643 		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
644 
645 		if (!list_empty(&call->link)) {
646 			spin_lock(&rxnet->call_lock);
647 			list_del_init(&call->link);
648 			spin_unlock(&rxnet->call_lock);
649 		}
650 
651 		rxrpc_cleanup_call(call);
652 	}
653 }
654 
655 /*
656  * Free up the call under RCU.
657  */
658 static void rxrpc_rcu_free_call(struct rcu_head *rcu)
659 {
660 	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
661 	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
662 
663 	kmem_cache_free(rxrpc_call_jar, call);
664 	if (atomic_dec_and_test(&rxnet->nr_calls))
665 		wake_up_var(&rxnet->nr_calls);
666 }
667 
668 /*
669  * Final call destruction - but must be done in process context.
670  */
671 static void rxrpc_destroy_call(struct work_struct *work)
672 {
673 	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
674 	struct rxrpc_txbuf *txb;
675 
676 	del_timer_sync(&call->timer);
677 
678 	rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack);
679 	rxrpc_cleanup_ring(call);
680 	while ((txb = list_first_entry_or_null(&call->tx_sendmsg,
681 					       struct rxrpc_txbuf, call_link))) {
682 		list_del(&txb->call_link);
683 		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
684 	}
685 	while ((txb = list_first_entry_or_null(&call->tx_buffer,
686 					       struct rxrpc_txbuf, call_link))) {
687 		list_del(&txb->call_link);
688 		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
689 	}
690 
691 	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
692 	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
693 	rxrpc_deactivate_bundle(call->bundle);
694 	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
695 	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
696 	rxrpc_put_local(call->local, rxrpc_local_put_call);
697 	call_rcu(&call->rcu, rxrpc_rcu_free_call);
698 }
699 
700 /*
701  * clean up a call
702  */
703 void rxrpc_cleanup_call(struct rxrpc_call *call)
704 {
705 	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
706 
707 	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
708 	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
709 
710 	del_timer(&call->timer);
711 
712 	if (rcu_read_lock_held())
713 		/* Can't use the rxrpc workqueue as we need to cancel/flush
714 		 * something that may be running/waiting there.
715 		 */
716 		schedule_work(&call->destroyer);
717 	else
718 		rxrpc_destroy_call(&call->destroyer);
719 }
720 
721 /*
722  * Make sure that all calls are gone from a network namespace.  To reach this
723  * point, any open UDP sockets in that namespace must have been closed, so any
724  * outstanding calls cannot be doing I/O.
725  */
726 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
727 {
728 	struct rxrpc_call *call;
729 
730 	_enter("");
731 
732 	if (!list_empty(&rxnet->calls)) {
733 		spin_lock(&rxnet->call_lock);
734 
735 		while (!list_empty(&rxnet->calls)) {
736 			call = list_entry(rxnet->calls.next,
737 					  struct rxrpc_call, link);
738 			_debug("Zapping call %p", call);
739 
740 			rxrpc_see_call(call, rxrpc_call_see_zap);
741 			list_del_init(&call->link);
742 
743 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
744 			       call, refcount_read(&call->ref),
745 			       rxrpc_call_states[__rxrpc_call_state(call)],
746 			       call->flags, call->events);
747 
748 			spin_unlock(&rxnet->call_lock);
749 			cond_resched();
750 			spin_lock(&rxnet->call_lock);
751 		}
752 
753 		spin_unlock(&rxnet->call_lock);
754 	}
755 
756 	atomic_dec(&rxnet->nr_calls);
757 	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
758 }
759