xref: /openbmc/linux/net/rxrpc/call_object.c (revision 024b2511)
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, jiffies);
74 		rxrpc_poke_call(call, rxrpc_call_poke_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->destroyer, rxrpc_destroy_call);
152 	INIT_LIST_HEAD(&call->link);
153 	INIT_LIST_HEAD(&call->wait_link);
154 	INIT_LIST_HEAD(&call->accept_link);
155 	INIT_LIST_HEAD(&call->recvmsg_link);
156 	INIT_LIST_HEAD(&call->sock_link);
157 	INIT_LIST_HEAD(&call->attend_link);
158 	INIT_LIST_HEAD(&call->tx_sendmsg);
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 	refcount_set(&call->ref, 1);
166 	call->debug_id = debug_id;
167 	call->tx_total_len = -1;
168 	call->next_rx_timo = 20 * HZ;
169 	call->next_req_timo = 1 * HZ;
170 	call->ackr_window = 1;
171 	call->ackr_wtop = 1;
172 
173 	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
174 
175 	call->rx_winsize = rxrpc_rx_window_size;
176 	call->tx_winsize = 16;
177 
178 	if (RXRPC_TX_SMSS > 2190)
179 		call->cong_cwnd = 2;
180 	else if (RXRPC_TX_SMSS > 1095)
181 		call->cong_cwnd = 3;
182 	else
183 		call->cong_cwnd = 4;
184 	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
185 
186 	call->rxnet = rxnet;
187 	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
188 	atomic_inc(&rxnet->nr_calls);
189 	return call;
190 }
191 
192 /*
193  * Allocate a new client call.
194  */
195 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
196 						  struct sockaddr_rxrpc *srx,
197 						  struct rxrpc_conn_parameters *cp,
198 						  struct rxrpc_call_params *p,
199 						  gfp_t gfp,
200 						  unsigned int debug_id)
201 {
202 	struct rxrpc_call *call;
203 	ktime_t now;
204 	int ret;
205 
206 	_enter("");
207 
208 	call = rxrpc_alloc_call(rx, gfp, debug_id);
209 	if (!call)
210 		return ERR_PTR(-ENOMEM);
211 	now = ktime_get_real();
212 	call->acks_latest_ts	= now;
213 	call->cong_tstamp	= now;
214 	call->dest_srx		= *srx;
215 	call->interruptibility	= p->interruptibility;
216 	call->tx_total_len	= p->tx_total_len;
217 	call->key		= key_get(cp->key);
218 	call->local		= rxrpc_get_local(cp->local, rxrpc_local_get_call);
219 	call->security_level	= cp->security_level;
220 	if (p->kernel)
221 		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
222 	if (cp->upgrade)
223 		__set_bit(RXRPC_CALL_UPGRADE, &call->flags);
224 	if (cp->exclusive)
225 		__set_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
226 
227 	if (p->timeouts.normal)
228 		call->next_rx_timo = min(msecs_to_jiffies(p->timeouts.normal), 1UL);
229 	if (p->timeouts.idle)
230 		call->next_req_timo = min(msecs_to_jiffies(p->timeouts.idle), 1UL);
231 	if (p->timeouts.hard)
232 		call->hard_timo = p->timeouts.hard * HZ;
233 
234 	ret = rxrpc_init_client_call_security(call);
235 	if (ret < 0) {
236 		rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret);
237 		rxrpc_put_call(call, rxrpc_call_put_discard_error);
238 		return ERR_PTR(ret);
239 	}
240 
241 	rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_CONN);
242 
243 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
244 			 p->user_call_ID, rxrpc_call_new_client);
245 
246 	_leave(" = %p", call);
247 	return call;
248 }
249 
250 /*
251  * Initiate the call ack/resend/expiry timer.
252  */
253 void rxrpc_start_call_timer(struct rxrpc_call *call)
254 {
255 	unsigned long now = jiffies;
256 	unsigned long j = now + MAX_JIFFY_OFFSET;
257 
258 	call->delay_ack_at = j;
259 	call->ack_lost_at = j;
260 	call->resend_at = j;
261 	call->ping_at = j;
262 	call->keepalive_at = j;
263 	call->expect_rx_by = j;
264 	call->expect_req_by = j;
265 	call->expect_term_by = j + call->hard_timo;
266 	call->timer.expires = now;
267 }
268 
269 /*
270  * Wait for a call slot to become available.
271  */
272 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
273 {
274 	struct semaphore *limiter = &rxrpc_call_limiter;
275 
276 	if (p->kernel)
277 		limiter = &rxrpc_kernel_call_limiter;
278 	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
279 		down(limiter);
280 		return limiter;
281 	}
282 	return down_interruptible(limiter) < 0 ? NULL : limiter;
283 }
284 
285 /*
286  * Release a call slot.
287  */
288 static void rxrpc_put_call_slot(struct rxrpc_call *call)
289 {
290 	struct semaphore *limiter = &rxrpc_call_limiter;
291 
292 	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
293 		limiter = &rxrpc_kernel_call_limiter;
294 	up(limiter);
295 }
296 
297 /*
298  * Start the process of connecting a call.  We obtain a peer and a connection
299  * bundle, but the actual association of a call with a connection is offloaded
300  * to the I/O thread to simplify locking.
301  */
302 static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
303 {
304 	struct rxrpc_local *local = call->local;
305 	int ret = -ENOMEM;
306 
307 	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
308 
309 	call->peer = rxrpc_lookup_peer(local, &call->dest_srx, gfp);
310 	if (!call->peer)
311 		goto error;
312 
313 	ret = rxrpc_look_up_bundle(call, gfp);
314 	if (ret < 0)
315 		goto error;
316 
317 	trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
318 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
319 	spin_lock(&local->client_call_lock);
320 	list_add_tail(&call->wait_link, &local->new_client_calls);
321 	spin_unlock(&local->client_call_lock);
322 	rxrpc_wake_up_io_thread(local);
323 	return 0;
324 
325 error:
326 	__set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
327 	return ret;
328 }
329 
330 /*
331  * Set up a call for the given parameters.
332  * - Called with the socket lock held, which it must release.
333  * - If it returns a call, the call's lock will need releasing by the caller.
334  */
335 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
336 					 struct rxrpc_conn_parameters *cp,
337 					 struct sockaddr_rxrpc *srx,
338 					 struct rxrpc_call_params *p,
339 					 gfp_t gfp,
340 					 unsigned int debug_id)
341 	__releases(&rx->sk.sk_lock.slock)
342 	__acquires(&call->user_mutex)
343 {
344 	struct rxrpc_call *call, *xcall;
345 	struct rxrpc_net *rxnet;
346 	struct semaphore *limiter;
347 	struct rb_node *parent, **pp;
348 	int ret;
349 
350 	_enter("%p,%lx", rx, p->user_call_ID);
351 
352 	limiter = rxrpc_get_call_slot(p, gfp);
353 	if (!limiter) {
354 		release_sock(&rx->sk);
355 		return ERR_PTR(-ERESTARTSYS);
356 	}
357 
358 	call = rxrpc_alloc_client_call(rx, srx, cp, p, gfp, debug_id);
359 	if (IS_ERR(call)) {
360 		release_sock(&rx->sk);
361 		up(limiter);
362 		_leave(" = %ld", PTR_ERR(call));
363 		return call;
364 	}
365 
366 	/* We need to protect a partially set up call against the user as we
367 	 * will be acting outside the socket lock.
368 	 */
369 	mutex_lock(&call->user_mutex);
370 
371 	/* Publish the call, even though it is incompletely set up as yet */
372 	write_lock(&rx->call_lock);
373 
374 	pp = &rx->calls.rb_node;
375 	parent = NULL;
376 	while (*pp) {
377 		parent = *pp;
378 		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
379 
380 		if (p->user_call_ID < xcall->user_call_ID)
381 			pp = &(*pp)->rb_left;
382 		else if (p->user_call_ID > xcall->user_call_ID)
383 			pp = &(*pp)->rb_right;
384 		else
385 			goto error_dup_user_ID;
386 	}
387 
388 	rcu_assign_pointer(call->socket, rx);
389 	call->user_call_ID = p->user_call_ID;
390 	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
391 	rxrpc_get_call(call, rxrpc_call_get_userid);
392 	rb_link_node(&call->sock_node, parent, pp);
393 	rb_insert_color(&call->sock_node, &rx->calls);
394 	list_add(&call->sock_link, &rx->sock_calls);
395 
396 	write_unlock(&rx->call_lock);
397 
398 	rxnet = call->rxnet;
399 	spin_lock(&rxnet->call_lock);
400 	list_add_tail_rcu(&call->link, &rxnet->calls);
401 	spin_unlock(&rxnet->call_lock);
402 
403 	/* From this point on, the call is protected by its own lock. */
404 	release_sock(&rx->sk);
405 
406 	/* Set up or get a connection record and set the protocol parameters,
407 	 * including channel number and call ID.
408 	 */
409 	ret = rxrpc_connect_call(call, gfp);
410 	if (ret < 0)
411 		goto error_attached_to_socket;
412 
413 	_leave(" = %p [new]", call);
414 	return call;
415 
416 	/* We unexpectedly found the user ID in the list after taking
417 	 * the call_lock.  This shouldn't happen unless the user races
418 	 * with itself and tries to add the same user ID twice at the
419 	 * same time in different threads.
420 	 */
421 error_dup_user_ID:
422 	write_unlock(&rx->call_lock);
423 	release_sock(&rx->sk);
424 	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
425 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
426 			 rxrpc_call_see_userid_exists);
427 	mutex_unlock(&call->user_mutex);
428 	rxrpc_put_call(call, rxrpc_call_put_userid_exists);
429 	_leave(" = -EEXIST");
430 	return ERR_PTR(-EEXIST);
431 
432 	/* We got an error, but the call is attached to the socket and is in
433 	 * need of release.  However, we might now race with recvmsg() when it
434 	 * completion notifies the socket.  Return 0 from sys_sendmsg() and
435 	 * leave the error to recvmsg() to deal with.
436 	 */
437 error_attached_to_socket:
438 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
439 			 rxrpc_call_see_connect_failed);
440 	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
441 	_leave(" = c=%08x [err]", call->debug_id);
442 	return call;
443 }
444 
445 /*
446  * Set up an incoming call.  call->conn points to the connection.
447  * This is called in BH context and isn't allowed to fail.
448  */
449 void rxrpc_incoming_call(struct rxrpc_sock *rx,
450 			 struct rxrpc_call *call,
451 			 struct sk_buff *skb)
452 {
453 	struct rxrpc_connection *conn = call->conn;
454 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
455 	u32 chan;
456 
457 	_enter(",%d", call->conn->debug_id);
458 
459 	rcu_assign_pointer(call->socket, rx);
460 	call->call_id		= sp->hdr.callNumber;
461 	call->dest_srx.srx_service = sp->hdr.serviceId;
462 	call->cid		= sp->hdr.cid;
463 	call->cong_tstamp	= skb->tstamp;
464 
465 	__set_bit(RXRPC_CALL_EXPOSED, &call->flags);
466 	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
467 
468 	spin_lock(&conn->state_lock);
469 
470 	switch (conn->state) {
471 	case RXRPC_CONN_SERVICE_UNSECURED:
472 	case RXRPC_CONN_SERVICE_CHALLENGING:
473 		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
474 		break;
475 	case RXRPC_CONN_SERVICE:
476 		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
477 		break;
478 
479 	case RXRPC_CONN_ABORTED:
480 		rxrpc_set_call_completion(call, conn->completion,
481 					  conn->abort_code, conn->error);
482 		break;
483 	default:
484 		BUG();
485 	}
486 
487 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
488 
489 	/* Set the channel for this call.  We don't get channel_lock as we're
490 	 * only defending against the data_ready handler (which we're called
491 	 * from) and the RESPONSE packet parser (which is only really
492 	 * interested in call_counter and can cope with a disagreement with the
493 	 * call pointer).
494 	 */
495 	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
496 	conn->channels[chan].call_counter = call->call_id;
497 	conn->channels[chan].call_id = call->call_id;
498 	conn->channels[chan].call = call;
499 	spin_unlock(&conn->state_lock);
500 
501 	spin_lock(&conn->peer->lock);
502 	hlist_add_head(&call->error_link, &conn->peer->error_targets);
503 	spin_unlock(&conn->peer->lock);
504 
505 	rxrpc_start_call_timer(call);
506 	_leave("");
507 }
508 
509 /*
510  * Note the re-emergence of a call.
511  */
512 void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
513 {
514 	if (call) {
515 		int r = refcount_read(&call->ref);
516 
517 		trace_rxrpc_call(call->debug_id, r, 0, why);
518 	}
519 }
520 
521 struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call,
522 				      enum rxrpc_call_trace why)
523 {
524 	int r;
525 
526 	if (!call || !__refcount_inc_not_zero(&call->ref, &r))
527 		return NULL;
528 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
529 	return call;
530 }
531 
532 /*
533  * Note the addition of a ref on a call.
534  */
535 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
536 {
537 	int r;
538 
539 	__refcount_inc(&call->ref, &r);
540 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
541 }
542 
543 /*
544  * Clean up the Rx skb ring.
545  */
546 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
547 {
548 	rxrpc_purge_queue(&call->recvmsg_queue);
549 	rxrpc_purge_queue(&call->rx_oos_queue);
550 }
551 
552 /*
553  * Detach a call from its owning socket.
554  */
555 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
556 {
557 	struct rxrpc_connection *conn = call->conn;
558 	bool put = false, putu = false;
559 
560 	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
561 
562 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
563 			 call->flags, rxrpc_call_see_release);
564 
565 	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
566 		BUG();
567 
568 	rxrpc_put_call_slot(call);
569 
570 	/* Make sure we don't get any more notifications */
571 	spin_lock(&rx->recvmsg_lock);
572 
573 	if (!list_empty(&call->recvmsg_link)) {
574 		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
575 		       call, call->events, call->flags);
576 		list_del(&call->recvmsg_link);
577 		put = true;
578 	}
579 
580 	/* list_empty() must return false in rxrpc_notify_socket() */
581 	call->recvmsg_link.next = NULL;
582 	call->recvmsg_link.prev = NULL;
583 
584 	spin_unlock(&rx->recvmsg_lock);
585 	if (put)
586 		rxrpc_put_call(call, rxrpc_call_put_unnotify);
587 
588 	write_lock(&rx->call_lock);
589 
590 	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
591 		rb_erase(&call->sock_node, &rx->calls);
592 		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
593 		putu = true;
594 	}
595 
596 	list_del(&call->sock_link);
597 	write_unlock(&rx->call_lock);
598 
599 	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
600 
601 	if (putu)
602 		rxrpc_put_call(call, rxrpc_call_put_userid);
603 
604 	_leave("");
605 }
606 
607 /*
608  * release all the calls associated with a socket
609  */
610 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
611 {
612 	struct rxrpc_call *call;
613 
614 	_enter("%p", rx);
615 
616 	while (!list_empty(&rx->to_be_accepted)) {
617 		call = list_entry(rx->to_be_accepted.next,
618 				  struct rxrpc_call, accept_link);
619 		list_del(&call->accept_link);
620 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
621 				    rxrpc_abort_call_sock_release_tba);
622 		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
623 	}
624 
625 	while (!list_empty(&rx->sock_calls)) {
626 		call = list_entry(rx->sock_calls.next,
627 				  struct rxrpc_call, sock_link);
628 		rxrpc_get_call(call, rxrpc_call_get_release_sock);
629 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
630 				    rxrpc_abort_call_sock_release);
631 		rxrpc_release_call(rx, call);
632 		rxrpc_put_call(call, rxrpc_call_put_release_sock);
633 	}
634 
635 	_leave("");
636 }
637 
638 /*
639  * release a call
640  */
641 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
642 {
643 	struct rxrpc_net *rxnet = call->rxnet;
644 	unsigned int debug_id = call->debug_id;
645 	bool dead;
646 	int r;
647 
648 	ASSERT(call != NULL);
649 
650 	dead = __refcount_dec_and_test(&call->ref, &r);
651 	trace_rxrpc_call(debug_id, r - 1, 0, why);
652 	if (dead) {
653 		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
654 
655 		if (!list_empty(&call->link)) {
656 			spin_lock(&rxnet->call_lock);
657 			list_del_init(&call->link);
658 			spin_unlock(&rxnet->call_lock);
659 		}
660 
661 		rxrpc_cleanup_call(call);
662 	}
663 }
664 
665 /*
666  * Free up the call under RCU.
667  */
668 static void rxrpc_rcu_free_call(struct rcu_head *rcu)
669 {
670 	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
671 	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
672 
673 	kmem_cache_free(rxrpc_call_jar, call);
674 	if (atomic_dec_and_test(&rxnet->nr_calls))
675 		wake_up_var(&rxnet->nr_calls);
676 }
677 
678 /*
679  * Final call destruction - but must be done in process context.
680  */
681 static void rxrpc_destroy_call(struct work_struct *work)
682 {
683 	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
684 	struct rxrpc_txbuf *txb;
685 
686 	del_timer_sync(&call->timer);
687 
688 	rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack);
689 	rxrpc_cleanup_ring(call);
690 	while ((txb = list_first_entry_or_null(&call->tx_sendmsg,
691 					       struct rxrpc_txbuf, call_link))) {
692 		list_del(&txb->call_link);
693 		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
694 	}
695 	while ((txb = list_first_entry_or_null(&call->tx_buffer,
696 					       struct rxrpc_txbuf, call_link))) {
697 		list_del(&txb->call_link);
698 		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
699 	}
700 
701 	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
702 	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
703 	rxrpc_deactivate_bundle(call->bundle);
704 	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
705 	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
706 	rxrpc_put_local(call->local, rxrpc_local_put_call);
707 	call_rcu(&call->rcu, rxrpc_rcu_free_call);
708 }
709 
710 /*
711  * clean up a call
712  */
713 void rxrpc_cleanup_call(struct rxrpc_call *call)
714 {
715 	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
716 
717 	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
718 	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
719 
720 	del_timer(&call->timer);
721 
722 	if (rcu_read_lock_held())
723 		/* Can't use the rxrpc workqueue as we need to cancel/flush
724 		 * something that may be running/waiting there.
725 		 */
726 		schedule_work(&call->destroyer);
727 	else
728 		rxrpc_destroy_call(&call->destroyer);
729 }
730 
731 /*
732  * Make sure that all calls are gone from a network namespace.  To reach this
733  * point, any open UDP sockets in that namespace must have been closed, so any
734  * outstanding calls cannot be doing I/O.
735  */
736 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
737 {
738 	struct rxrpc_call *call;
739 
740 	_enter("");
741 
742 	if (!list_empty(&rxnet->calls)) {
743 		spin_lock(&rxnet->call_lock);
744 
745 		while (!list_empty(&rxnet->calls)) {
746 			call = list_entry(rxnet->calls.next,
747 					  struct rxrpc_call, link);
748 			_debug("Zapping call %p", call);
749 
750 			rxrpc_see_call(call, rxrpc_call_see_zap);
751 			list_del_init(&call->link);
752 
753 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
754 			       call, refcount_read(&call->ref),
755 			       rxrpc_call_states[__rxrpc_call_state(call)],
756 			       call->flags, call->events);
757 
758 			spin_unlock(&rxnet->call_lock);
759 			cond_resched();
760 			spin_lock(&rxnet->call_lock);
761 		}
762 
763 		spin_unlock(&rxnet->call_lock);
764 	}
765 
766 	atomic_dec(&rxnet->nr_calls);
767 	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
768 }
769