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
18const 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
33const 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
41struct kmem_cache *rxrpc_call_jar;
42
43static DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000);
44static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000);
45
46void 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
66static 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
78static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
79
80static void rxrpc_destroy_call(struct work_struct *);
81
82/*
83 * find an extant server call
84 * - called in process context with IRQs enabled
85 */
86struct 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
112found_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 */
122struct 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	if (RXRPC_TX_SMSS > 2190)
178		call->cong_cwnd = 2;
179	else if (RXRPC_TX_SMSS > 1095)
180		call->cong_cwnd = 3;
181	else
182		call->cong_cwnd = 4;
183	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
184
185	call->rxnet = rxnet;
186	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
187	atomic_inc(&rxnet->nr_calls);
188	return call;
189}
190
191/*
192 * Allocate a new client call.
193 */
194static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
195						  struct rxrpc_conn_parameters *cp,
196						  struct rxrpc_call_params *p,
197						  gfp_t gfp,
198						  unsigned int debug_id)
199{
200	struct rxrpc_call *call;
201	ktime_t now;
202	int ret;
203
204	_enter("");
205
206	call = rxrpc_alloc_call(rx, gfp, debug_id);
207	if (!call)
208		return ERR_PTR(-ENOMEM);
209	now = ktime_get_real();
210	call->acks_latest_ts	= now;
211	call->cong_tstamp	= now;
212	call->dest_srx		= cp->peer->srx;
213	call->dest_srx.srx_service = cp->service_id;
214	call->interruptibility	= p->interruptibility;
215	call->tx_total_len	= p->tx_total_len;
216	call->key		= key_get(cp->key);
217	call->peer		= rxrpc_get_peer(cp->peer, rxrpc_peer_get_call);
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(p->timeouts.normal, 1);
229	if (p->timeouts.idle)
230		call->next_req_timo = min(p->timeouts.idle, 1);
231	if (p->timeouts.hard)
232		call->hard_timo = p->timeouts.hard;
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 */
253void rxrpc_start_call_timer(struct rxrpc_call *call)
254{
255	if (call->hard_timo) {
256		ktime_t delay = ms_to_ktime(call->hard_timo * 1000);
257
258		call->expect_term_by = ktime_add(ktime_get_real(), delay);
259		trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
260	}
261	call->timer.expires = jiffies;
262}
263
264/*
265 * Wait for a call slot to become available.
266 */
267static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
268{
269	struct semaphore *limiter = &rxrpc_call_limiter;
270
271	if (p->kernel)
272		limiter = &rxrpc_kernel_call_limiter;
273	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
274		down(limiter);
275		return limiter;
276	}
277	return down_interruptible(limiter) < 0 ? NULL : limiter;
278}
279
280/*
281 * Release a call slot.
282 */
283static void rxrpc_put_call_slot(struct rxrpc_call *call)
284{
285	struct semaphore *limiter = &rxrpc_call_limiter;
286
287	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
288		limiter = &rxrpc_kernel_call_limiter;
289	up(limiter);
290}
291
292/*
293 * Start the process of connecting a call.  We obtain a peer and a connection
294 * bundle, but the actual association of a call with a connection is offloaded
295 * to the I/O thread to simplify locking.
296 */
297static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
298{
299	struct rxrpc_local *local = call->local;
300	int ret = -ENOMEM;
301
302	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
303
304	ret = rxrpc_look_up_bundle(call, gfp);
305	if (ret < 0)
306		goto error;
307
308	trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
309	rxrpc_get_call(call, rxrpc_call_get_io_thread);
310	spin_lock(&local->client_call_lock);
311	list_add_tail(&call->wait_link, &local->new_client_calls);
312	spin_unlock(&local->client_call_lock);
313	rxrpc_wake_up_io_thread(local);
314	return 0;
315
316error:
317	__set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
318	return ret;
319}
320
321/*
322 * Set up a call for the given parameters.
323 * - Called with the socket lock held, which it must release.
324 * - If it returns a call, the call's lock will need releasing by the caller.
325 */
326struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
327					 struct rxrpc_conn_parameters *cp,
328					 struct rxrpc_call_params *p,
329					 gfp_t gfp,
330					 unsigned int debug_id)
331	__releases(&rx->sk.sk_lock.slock)
332	__acquires(&call->user_mutex)
333{
334	struct rxrpc_call *call, *xcall;
335	struct rxrpc_net *rxnet;
336	struct semaphore *limiter;
337	struct rb_node *parent, **pp;
338	int ret;
339
340	_enter("%p,%lx", rx, p->user_call_ID);
341
342	if (WARN_ON_ONCE(!cp->peer)) {
343		release_sock(&rx->sk);
344		return ERR_PTR(-EIO);
345	}
346
347	limiter = rxrpc_get_call_slot(p, gfp);
348	if (!limiter) {
349		release_sock(&rx->sk);
350		return ERR_PTR(-ERESTARTSYS);
351	}
352
353	call = rxrpc_alloc_client_call(rx, cp, p, gfp, debug_id);
354	if (IS_ERR(call)) {
355		release_sock(&rx->sk);
356		up(limiter);
357		_leave(" = %ld", PTR_ERR(call));
358		return call;
359	}
360
361	/* We need to protect a partially set up call against the user as we
362	 * will be acting outside the socket lock.
363	 */
364	mutex_lock(&call->user_mutex);
365
366	/* Publish the call, even though it is incompletely set up as yet */
367	write_lock(&rx->call_lock);
368
369	pp = &rx->calls.rb_node;
370	parent = NULL;
371	while (*pp) {
372		parent = *pp;
373		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
374
375		if (p->user_call_ID < xcall->user_call_ID)
376			pp = &(*pp)->rb_left;
377		else if (p->user_call_ID > xcall->user_call_ID)
378			pp = &(*pp)->rb_right;
379		else
380			goto error_dup_user_ID;
381	}
382
383	rcu_assign_pointer(call->socket, rx);
384	call->user_call_ID = p->user_call_ID;
385	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
386	rxrpc_get_call(call, rxrpc_call_get_userid);
387	rb_link_node(&call->sock_node, parent, pp);
388	rb_insert_color(&call->sock_node, &rx->calls);
389	list_add(&call->sock_link, &rx->sock_calls);
390
391	write_unlock(&rx->call_lock);
392
393	rxnet = call->rxnet;
394	spin_lock(&rxnet->call_lock);
395	list_add_tail_rcu(&call->link, &rxnet->calls);
396	spin_unlock(&rxnet->call_lock);
397
398	/* From this point on, the call is protected by its own lock. */
399	release_sock(&rx->sk);
400
401	/* Set up or get a connection record and set the protocol parameters,
402	 * including channel number and call ID.
403	 */
404	ret = rxrpc_connect_call(call, gfp);
405	if (ret < 0)
406		goto error_attached_to_socket;
407
408	_leave(" = %p [new]", call);
409	return call;
410
411	/* We unexpectedly found the user ID in the list after taking
412	 * the call_lock.  This shouldn't happen unless the user races
413	 * with itself and tries to add the same user ID twice at the
414	 * same time in different threads.
415	 */
416error_dup_user_ID:
417	write_unlock(&rx->call_lock);
418	release_sock(&rx->sk);
419	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
420	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
421			 rxrpc_call_see_userid_exists);
422	mutex_unlock(&call->user_mutex);
423	rxrpc_put_call(call, rxrpc_call_put_userid_exists);
424	_leave(" = -EEXIST");
425	return ERR_PTR(-EEXIST);
426
427	/* We got an error, but the call is attached to the socket and is in
428	 * need of release.  However, we might now race with recvmsg() when it
429	 * completion notifies the socket.  Return 0 from sys_sendmsg() and
430	 * leave the error to recvmsg() to deal with.
431	 */
432error_attached_to_socket:
433	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
434			 rxrpc_call_see_connect_failed);
435	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
436	_leave(" = c=%08x [err]", call->debug_id);
437	return call;
438}
439
440/*
441 * Set up an incoming call.  call->conn points to the connection.
442 * This is called in BH context and isn't allowed to fail.
443 */
444void rxrpc_incoming_call(struct rxrpc_sock *rx,
445			 struct rxrpc_call *call,
446			 struct sk_buff *skb)
447{
448	struct rxrpc_connection *conn = call->conn;
449	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
450	u32 chan;
451
452	_enter(",%d", call->conn->debug_id);
453
454	rcu_assign_pointer(call->socket, rx);
455	call->call_id		= sp->hdr.callNumber;
456	call->dest_srx.srx_service = sp->hdr.serviceId;
457	call->cid		= sp->hdr.cid;
458	call->cong_tstamp	= skb->tstamp;
459
460	__set_bit(RXRPC_CALL_EXPOSED, &call->flags);
461	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
462
463	spin_lock(&conn->state_lock);
464
465	switch (conn->state) {
466	case RXRPC_CONN_SERVICE_UNSECURED:
467	case RXRPC_CONN_SERVICE_CHALLENGING:
468		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
469		break;
470	case RXRPC_CONN_SERVICE:
471		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
472		break;
473
474	case RXRPC_CONN_ABORTED:
475		rxrpc_set_call_completion(call, conn->completion,
476					  conn->abort_code, conn->error);
477		break;
478	default:
479		BUG();
480	}
481
482	rxrpc_get_call(call, rxrpc_call_get_io_thread);
483
484	/* Set the channel for this call.  We don't get channel_lock as we're
485	 * only defending against the data_ready handler (which we're called
486	 * from) and the RESPONSE packet parser (which is only really
487	 * interested in call_counter and can cope with a disagreement with the
488	 * call pointer).
489	 */
490	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
491	conn->channels[chan].call_counter = call->call_id;
492	conn->channels[chan].call_id = call->call_id;
493	conn->channels[chan].call = call;
494	spin_unlock(&conn->state_lock);
495
496	spin_lock(&conn->peer->lock);
497	hlist_add_head(&call->error_link, &conn->peer->error_targets);
498	spin_unlock(&conn->peer->lock);
499
500	rxrpc_start_call_timer(call);
501	_leave("");
502}
503
504/*
505 * Note the re-emergence of a call.
506 */
507void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
508{
509	if (call) {
510		int r = refcount_read(&call->ref);
511
512		trace_rxrpc_call(call->debug_id, r, 0, why);
513	}
514}
515
516struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call,
517				      enum rxrpc_call_trace why)
518{
519	int r;
520
521	if (!call || !__refcount_inc_not_zero(&call->ref, &r))
522		return NULL;
523	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
524	return call;
525}
526
527/*
528 * Note the addition of a ref on a call.
529 */
530void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
531{
532	int r;
533
534	__refcount_inc(&call->ref, &r);
535	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
536}
537
538/*
539 * Clean up the Rx skb ring.
540 */
541static void rxrpc_cleanup_ring(struct rxrpc_call *call)
542{
543	rxrpc_purge_queue(&call->recvmsg_queue);
544	rxrpc_purge_queue(&call->rx_oos_queue);
545}
546
547/*
548 * Detach a call from its owning socket.
549 */
550void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
551{
552	struct rxrpc_connection *conn = call->conn;
553	bool put = false, putu = false;
554
555	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
556
557	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
558			 call->flags, rxrpc_call_see_release);
559
560	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
561		BUG();
562
563	rxrpc_put_call_slot(call);
564
565	/* Make sure we don't get any more notifications */
566	spin_lock(&rx->recvmsg_lock);
567
568	if (!list_empty(&call->recvmsg_link)) {
569		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
570		       call, call->events, call->flags);
571		list_del(&call->recvmsg_link);
572		put = true;
573	}
574
575	/* list_empty() must return false in rxrpc_notify_socket() */
576	call->recvmsg_link.next = NULL;
577	call->recvmsg_link.prev = NULL;
578
579	spin_unlock(&rx->recvmsg_lock);
580	if (put)
581		rxrpc_put_call(call, rxrpc_call_put_unnotify);
582
583	write_lock(&rx->call_lock);
584
585	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
586		rb_erase(&call->sock_node, &rx->calls);
587		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
588		putu = true;
589	}
590
591	list_del(&call->sock_link);
592	write_unlock(&rx->call_lock);
593
594	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
595
596	if (putu)
597		rxrpc_put_call(call, rxrpc_call_put_userid);
598
599	_leave("");
600}
601
602/*
603 * release all the calls associated with a socket
604 */
605void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
606{
607	struct rxrpc_call *call;
608
609	_enter("%p", rx);
610
611	while (!list_empty(&rx->to_be_accepted)) {
612		call = list_entry(rx->to_be_accepted.next,
613				  struct rxrpc_call, accept_link);
614		list_del(&call->accept_link);
615		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
616				    rxrpc_abort_call_sock_release_tba);
617		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
618	}
619
620	while (!list_empty(&rx->sock_calls)) {
621		call = list_entry(rx->sock_calls.next,
622				  struct rxrpc_call, sock_link);
623		rxrpc_get_call(call, rxrpc_call_get_release_sock);
624		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
625				    rxrpc_abort_call_sock_release);
626		rxrpc_release_call(rx, call);
627		rxrpc_put_call(call, rxrpc_call_put_release_sock);
628	}
629
630	_leave("");
631}
632
633/*
634 * release a call
635 */
636void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
637{
638	struct rxrpc_net *rxnet = call->rxnet;
639	unsigned int debug_id = call->debug_id;
640	bool dead;
641	int r;
642
643	ASSERT(call != NULL);
644
645	dead = __refcount_dec_and_test(&call->ref, &r);
646	trace_rxrpc_call(debug_id, r - 1, 0, why);
647	if (dead) {
648		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
649
650		if (!list_empty(&call->link)) {
651			spin_lock(&rxnet->call_lock);
652			list_del_init(&call->link);
653			spin_unlock(&rxnet->call_lock);
654		}
655
656		rxrpc_cleanup_call(call);
657	}
658}
659
660/*
661 * Free up the call under RCU.
662 */
663static void rxrpc_rcu_free_call(struct rcu_head *rcu)
664{
665	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
666	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
667
668	kmem_cache_free(rxrpc_call_jar, call);
669	if (atomic_dec_and_test(&rxnet->nr_calls))
670		wake_up_var(&rxnet->nr_calls);
671}
672
673/*
674 * Final call destruction - but must be done in process context.
675 */
676static void rxrpc_destroy_call(struct work_struct *work)
677{
678	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
679	struct rxrpc_txbuf *txb;
680
681	del_timer_sync(&call->timer);
682
683	rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack);
684	rxrpc_cleanup_ring(call);
685	while ((txb = list_first_entry_or_null(&call->tx_sendmsg,
686					       struct rxrpc_txbuf, call_link))) {
687		list_del(&txb->call_link);
688		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
689	}
690	while ((txb = list_first_entry_or_null(&call->tx_buffer,
691					       struct rxrpc_txbuf, call_link))) {
692		list_del(&txb->call_link);
693		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
694	}
695
696	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
697	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
698	rxrpc_deactivate_bundle(call->bundle);
699	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
700	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
701	rxrpc_put_local(call->local, rxrpc_local_put_call);
702	call_rcu(&call->rcu, rxrpc_rcu_free_call);
703}
704
705/*
706 * clean up a call
707 */
708void rxrpc_cleanup_call(struct rxrpc_call *call)
709{
710	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
711
712	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
713	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
714
715	del_timer(&call->timer);
716
717	if (rcu_read_lock_held())
718		/* Can't use the rxrpc workqueue as we need to cancel/flush
719		 * something that may be running/waiting there.
720		 */
721		schedule_work(&call->destroyer);
722	else
723		rxrpc_destroy_call(&call->destroyer);
724}
725
726/*
727 * Make sure that all calls are gone from a network namespace.  To reach this
728 * point, any open UDP sockets in that namespace must have been closed, so any
729 * outstanding calls cannot be doing I/O.
730 */
731void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
732{
733	struct rxrpc_call *call;
734
735	_enter("");
736
737	if (!list_empty(&rxnet->calls)) {
738		spin_lock(&rxnet->call_lock);
739
740		while (!list_empty(&rxnet->calls)) {
741			call = list_entry(rxnet->calls.next,
742					  struct rxrpc_call, link);
743			_debug("Zapping call %p", call);
744
745			rxrpc_see_call(call, rxrpc_call_see_zap);
746			list_del_init(&call->link);
747
748			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
749			       call, refcount_read(&call->ref),
750			       rxrpc_call_states[__rxrpc_call_state(call)],
751			       call->flags, call->events);
752
753			spin_unlock(&rxnet->call_lock);
754			cond_resched();
755			spin_lock(&rxnet->call_lock);
756		}
757
758		spin_unlock(&rxnet->call_lock);
759	}
760
761	atomic_dec(&rxnet->nr_calls);
762	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
763}
764