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_RECV_REQUEST]	= "SvRcvReq",
 26	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
 27	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
 28	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
 29	[RXRPC_CALL_COMPLETE]			= "Complete",
 30};
 31
 32const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
 33	[RXRPC_CALL_SUCCEEDED]			= "Complete",
 34	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
 35	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
 36	[RXRPC_CALL_LOCAL_ERROR]		= "LocError",
 37	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
 38};
 39
 40struct kmem_cache *rxrpc_call_jar;
 41
 42static DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000);
 43static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000);
 44
 45void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what)
 46{
 47	struct rxrpc_local *local = call->local;
 48	bool busy;
 49
 50	if (!test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) {
 51		spin_lock_bh(&local->lock);
 52		busy = !list_empty(&call->attend_link);
 53		trace_rxrpc_poke_call(call, busy, what);
 54		if (!busy && !rxrpc_try_get_call(call, rxrpc_call_get_poke))
 55			busy = true;
 56		if (!busy) {
 57			list_add_tail(&call->attend_link, &local->call_attend_q);
 58		}
 59		spin_unlock_bh(&local->lock);
 60		if (!busy)
 61			rxrpc_wake_up_io_thread(local);
 62	}
 63}
 64
 65static void rxrpc_call_timer_expired(struct timer_list *t)
 66{
 67	struct rxrpc_call *call = from_timer(call, t, timer);
 68
 69	_enter("%d", call->debug_id);
 70
 71	if (!__rxrpc_call_is_complete(call)) {
 72		trace_rxrpc_timer_expired(call);
 73		rxrpc_poke_call(call, rxrpc_call_poke_timer);
 74	}
 75}
 76
 
 
 
 
 
 
 
 
 
 77static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
 78
 79static void rxrpc_destroy_call(struct work_struct *);
 80
 81/*
 82 * find an extant server call
 83 * - called in process context with IRQs enabled
 84 */
 85struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
 86					      unsigned long user_call_ID)
 87{
 88	struct rxrpc_call *call;
 89	struct rb_node *p;
 90
 91	_enter("%p,%lx", rx, user_call_ID);
 92
 93	read_lock(&rx->call_lock);
 94
 95	p = rx->calls.rb_node;
 96	while (p) {
 97		call = rb_entry(p, struct rxrpc_call, sock_node);
 98
 99		if (user_call_ID < call->user_call_ID)
100			p = p->rb_left;
101		else if (user_call_ID > call->user_call_ID)
102			p = p->rb_right;
103		else
104			goto found_extant_call;
105	}
106
107	read_unlock(&rx->call_lock);
108	_leave(" = NULL");
109	return NULL;
110
111found_extant_call:
112	rxrpc_get_call(call, rxrpc_call_get_sendmsg);
113	read_unlock(&rx->call_lock);
114	_leave(" = %p [%d]", call, refcount_read(&call->ref));
115	return call;
116}
117
118/*
119 * allocate a new call
120 */
121struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
122				    unsigned int debug_id)
123{
124	struct rxrpc_call *call;
125	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
126
127	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
128	if (!call)
129		return NULL;
130
131	mutex_init(&call->user_mutex);
132
133	/* Prevent lockdep reporting a deadlock false positive between the afs
134	 * filesystem and sys_sendmsg() via the mmap sem.
135	 */
136	if (rx->sk.sk_kern_sock)
137		lockdep_set_class(&call->user_mutex,
138				  &rxrpc_call_user_mutex_lock_class_key);
139
140	timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
141	INIT_WORK(&call->destroyer, rxrpc_destroy_call);
142	INIT_LIST_HEAD(&call->link);
143	INIT_LIST_HEAD(&call->wait_link);
144	INIT_LIST_HEAD(&call->accept_link);
145	INIT_LIST_HEAD(&call->recvmsg_link);
146	INIT_LIST_HEAD(&call->sock_link);
147	INIT_LIST_HEAD(&call->attend_link);
148	INIT_LIST_HEAD(&call->tx_sendmsg);
149	INIT_LIST_HEAD(&call->tx_buffer);
150	skb_queue_head_init(&call->recvmsg_queue);
151	skb_queue_head_init(&call->rx_oos_queue);
152	init_waitqueue_head(&call->waitq);
153	spin_lock_init(&call->notify_lock);
154	spin_lock_init(&call->tx_lock);
155	refcount_set(&call->ref, 1);
156	call->debug_id		= debug_id;
157	call->tx_total_len	= -1;
158	call->next_rx_timo	= 20 * HZ;
159	call->next_req_timo	= 1 * HZ;
160	call->ackr_window	= 1;
161	call->ackr_wtop		= 1;
162	call->delay_ack_at	= KTIME_MAX;
163	call->ack_lost_at	= KTIME_MAX;
164	call->resend_at		= KTIME_MAX;
165	call->ping_at		= KTIME_MAX;
166	call->keepalive_at	= KTIME_MAX;
167	call->expect_rx_by	= KTIME_MAX;
168	call->expect_req_by	= KTIME_MAX;
169	call->expect_term_by	= KTIME_MAX;
170
171	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
172
173	call->rx_winsize = rxrpc_rx_window_size;
174	call->tx_winsize = 16;
175
176	call->cong_cwnd = RXRPC_MIN_CWND;
 
 
 
 
 
177	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
178
179	call->rxnet = rxnet;
180	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
181	atomic_inc(&rxnet->nr_calls);
182	return call;
183}
184
185/*
186 * Allocate a new client call.
187 */
188static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
189						  struct rxrpc_conn_parameters *cp,
190						  struct rxrpc_call_params *p,
191						  gfp_t gfp,
192						  unsigned int debug_id)
193{
194	struct rxrpc_call *call;
195	ktime_t now;
196	int ret;
197
198	_enter("");
199
200	call = rxrpc_alloc_call(rx, gfp, debug_id);
201	if (!call)
202		return ERR_PTR(-ENOMEM);
203	now = ktime_get_real();
204	call->acks_latest_ts	= now;
205	call->cong_tstamp	= now;
206	call->dest_srx		= cp->peer->srx;
207	call->dest_srx.srx_service = cp->service_id;
208	call->interruptibility	= p->interruptibility;
209	call->tx_total_len	= p->tx_total_len;
210	call->key		= key_get(cp->key);
211	call->peer		= rxrpc_get_peer(cp->peer, rxrpc_peer_get_call);
212	call->local		= rxrpc_get_local(cp->local, rxrpc_local_get_call);
213	call->security_level	= cp->security_level;
214	if (p->kernel)
215		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
216	if (cp->upgrade)
217		__set_bit(RXRPC_CALL_UPGRADE, &call->flags);
218	if (cp->exclusive)
219		__set_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
220
221	if (p->timeouts.normal)
222		call->next_rx_timo = min(p->timeouts.normal, 1);
223	if (p->timeouts.idle)
224		call->next_req_timo = min(p->timeouts.idle, 1);
225	if (p->timeouts.hard)
226		call->hard_timo = p->timeouts.hard;
227
228	ret = rxrpc_init_client_call_security(call);
229	if (ret < 0) {
230		rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret);
231		rxrpc_put_call(call, rxrpc_call_put_discard_error);
232		return ERR_PTR(ret);
233	}
234
235	rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_CONN);
236
237	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
238			 p->user_call_ID, rxrpc_call_new_client);
239
240	_leave(" = %p", call);
241	return call;
242}
243
244/*
245 * Initiate the call ack/resend/expiry timer.
246 */
247void rxrpc_start_call_timer(struct rxrpc_call *call)
248{
249	if (call->hard_timo) {
250		ktime_t delay = ms_to_ktime(call->hard_timo * 1000);
251
252		call->expect_term_by = ktime_add(ktime_get_real(), delay);
253		trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
254	}
255	call->timer.expires = jiffies;
 
 
 
 
 
256}
257
258/*
259 * Wait for a call slot to become available.
260 */
261static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
262{
263	struct semaphore *limiter = &rxrpc_call_limiter;
264
265	if (p->kernel)
266		limiter = &rxrpc_kernel_call_limiter;
267	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
268		down(limiter);
269		return limiter;
270	}
271	return down_interruptible(limiter) < 0 ? NULL : limiter;
272}
273
274/*
275 * Release a call slot.
276 */
277static void rxrpc_put_call_slot(struct rxrpc_call *call)
278{
279	struct semaphore *limiter = &rxrpc_call_limiter;
280
281	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
282		limiter = &rxrpc_kernel_call_limiter;
283	up(limiter);
284}
285
286/*
287 * Start the process of connecting a call.  We obtain a peer and a connection
288 * bundle, but the actual association of a call with a connection is offloaded
289 * to the I/O thread to simplify locking.
290 */
291static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
292{
293	struct rxrpc_local *local = call->local;
294	int ret = -ENOMEM;
295
296	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
297
298	ret = rxrpc_look_up_bundle(call, gfp);
299	if (ret < 0)
300		goto error;
301
302	trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
303	rxrpc_get_call(call, rxrpc_call_get_io_thread);
304	spin_lock(&local->client_call_lock);
305	list_add_tail(&call->wait_link, &local->new_client_calls);
306	spin_unlock(&local->client_call_lock);
307	rxrpc_wake_up_io_thread(local);
308	return 0;
309
310error:
311	__set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
312	return ret;
313}
314
315/*
316 * Set up a call for the given parameters.
317 * - Called with the socket lock held, which it must release.
318 * - If it returns a call, the call's lock will need releasing by the caller.
319 */
320struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
321					 struct rxrpc_conn_parameters *cp,
322					 struct rxrpc_call_params *p,
323					 gfp_t gfp,
324					 unsigned int debug_id)
325	__releases(&rx->sk.sk_lock.slock)
326	__acquires(&call->user_mutex)
327{
328	struct rxrpc_call *call, *xcall;
329	struct rxrpc_net *rxnet;
330	struct semaphore *limiter;
331	struct rb_node *parent, **pp;
332	int ret;
333
334	_enter("%p,%lx", rx, p->user_call_ID);
335
336	if (WARN_ON_ONCE(!cp->peer)) {
337		release_sock(&rx->sk);
338		return ERR_PTR(-EIO);
339	}
340
341	limiter = rxrpc_get_call_slot(p, gfp);
342	if (!limiter) {
343		release_sock(&rx->sk);
344		return ERR_PTR(-ERESTARTSYS);
345	}
346
347	call = rxrpc_alloc_client_call(rx, cp, p, gfp, debug_id);
348	if (IS_ERR(call)) {
349		release_sock(&rx->sk);
350		up(limiter);
351		_leave(" = %ld", PTR_ERR(call));
352		return call;
353	}
354
355	/* We need to protect a partially set up call against the user as we
356	 * will be acting outside the socket lock.
357	 */
358	mutex_lock(&call->user_mutex);
359
360	/* Publish the call, even though it is incompletely set up as yet */
361	write_lock(&rx->call_lock);
362
363	pp = &rx->calls.rb_node;
364	parent = NULL;
365	while (*pp) {
366		parent = *pp;
367		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
368
369		if (p->user_call_ID < xcall->user_call_ID)
370			pp = &(*pp)->rb_left;
371		else if (p->user_call_ID > xcall->user_call_ID)
372			pp = &(*pp)->rb_right;
373		else
374			goto error_dup_user_ID;
375	}
376
377	rcu_assign_pointer(call->socket, rx);
378	call->user_call_ID = p->user_call_ID;
379	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
380	rxrpc_get_call(call, rxrpc_call_get_userid);
381	rb_link_node(&call->sock_node, parent, pp);
382	rb_insert_color(&call->sock_node, &rx->calls);
383	list_add(&call->sock_link, &rx->sock_calls);
384
385	write_unlock(&rx->call_lock);
386
387	rxnet = call->rxnet;
388	spin_lock(&rxnet->call_lock);
389	list_add_tail_rcu(&call->link, &rxnet->calls);
390	spin_unlock(&rxnet->call_lock);
391
392	/* From this point on, the call is protected by its own lock. */
393	release_sock(&rx->sk);
394
395	/* Set up or get a connection record and set the protocol parameters,
396	 * including channel number and call ID.
397	 */
398	ret = rxrpc_connect_call(call, gfp);
399	if (ret < 0)
400		goto error_attached_to_socket;
401
402	_leave(" = %p [new]", call);
403	return call;
404
405	/* We unexpectedly found the user ID in the list after taking
406	 * the call_lock.  This shouldn't happen unless the user races
407	 * with itself and tries to add the same user ID twice at the
408	 * same time in different threads.
409	 */
410error_dup_user_ID:
411	write_unlock(&rx->call_lock);
412	release_sock(&rx->sk);
413	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
414	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
415			 rxrpc_call_see_userid_exists);
416	mutex_unlock(&call->user_mutex);
417	rxrpc_put_call(call, rxrpc_call_put_userid_exists);
418	_leave(" = -EEXIST");
419	return ERR_PTR(-EEXIST);
420
421	/* We got an error, but the call is attached to the socket and is in
422	 * need of release.  However, we might now race with recvmsg() when it
423	 * completion notifies the socket.  Return 0 from sys_sendmsg() and
424	 * leave the error to recvmsg() to deal with.
425	 */
426error_attached_to_socket:
427	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
428			 rxrpc_call_see_connect_failed);
429	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
430	_leave(" = c=%08x [err]", call->debug_id);
431	return call;
432}
433
434/*
435 * Set up an incoming call.  call->conn points to the connection.
436 * This is called in BH context and isn't allowed to fail.
437 */
438void rxrpc_incoming_call(struct rxrpc_sock *rx,
439			 struct rxrpc_call *call,
440			 struct sk_buff *skb)
441{
442	struct rxrpc_connection *conn = call->conn;
443	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
444	u32 chan;
445
446	_enter(",%d", call->conn->debug_id);
447
448	rcu_assign_pointer(call->socket, rx);
449	call->call_id		= sp->hdr.callNumber;
450	call->dest_srx.srx_service = sp->hdr.serviceId;
451	call->cid		= sp->hdr.cid;
452	call->cong_tstamp	= skb->tstamp;
453
454	__set_bit(RXRPC_CALL_EXPOSED, &call->flags);
455	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
456
457	spin_lock(&conn->state_lock);
458
459	switch (conn->state) {
460	case RXRPC_CONN_SERVICE_UNSECURED:
461	case RXRPC_CONN_SERVICE_CHALLENGING:
462		__set_bit(RXRPC_CALL_CONN_CHALLENGING, &call->flags);
463		break;
464	case RXRPC_CONN_SERVICE:
 
465		break;
466
467	case RXRPC_CONN_ABORTED:
468		rxrpc_set_call_completion(call, conn->completion,
469					  conn->abort_code, conn->error);
470		break;
471	default:
472		BUG();
473	}
474
475	rxrpc_get_call(call, rxrpc_call_get_io_thread);
476
477	/* Set the channel for this call.  We don't get channel_lock as we're
478	 * only defending against the data_ready handler (which we're called
479	 * from) and the RESPONSE packet parser (which is only really
480	 * interested in call_counter and can cope with a disagreement with the
481	 * call pointer).
482	 */
483	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
484	conn->channels[chan].call_counter = call->call_id;
485	conn->channels[chan].call_id = call->call_id;
486	conn->channels[chan].call = call;
487	spin_unlock(&conn->state_lock);
488
489	spin_lock(&conn->peer->lock);
490	hlist_add_head(&call->error_link, &conn->peer->error_targets);
491	spin_unlock(&conn->peer->lock);
492
493	rxrpc_start_call_timer(call);
494	_leave("");
495}
496
497/*
498 * Note the re-emergence of a call.
499 */
500void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
501{
502	if (call) {
503		int r = refcount_read(&call->ref);
504
505		trace_rxrpc_call(call->debug_id, r, 0, why);
506	}
507}
508
509struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call,
510				      enum rxrpc_call_trace why)
511{
512	int r;
513
514	if (!call || !__refcount_inc_not_zero(&call->ref, &r))
515		return NULL;
516	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
517	return call;
518}
519
520/*
521 * Note the addition of a ref on a call.
522 */
523void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
524{
525	int r;
526
527	__refcount_inc(&call->ref, &r);
528	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
529}
530
531/*
532 * Clean up the Rx skb ring.
533 */
534static void rxrpc_cleanup_ring(struct rxrpc_call *call)
535{
536	rxrpc_purge_queue(&call->recvmsg_queue);
537	rxrpc_purge_queue(&call->rx_oos_queue);
538}
539
540/*
541 * Detach a call from its owning socket.
542 */
543void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
544{
545	struct rxrpc_connection *conn = call->conn;
546	bool put = false, putu = false;
547
548	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
549
550	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
551			 call->flags, rxrpc_call_see_release);
552
553	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
554		BUG();
555
556	rxrpc_put_call_slot(call);
557
558	/* Make sure we don't get any more notifications */
559	spin_lock(&rx->recvmsg_lock);
560
561	if (!list_empty(&call->recvmsg_link)) {
562		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
563		       call, call->events, call->flags);
564		list_del(&call->recvmsg_link);
565		put = true;
566	}
567
568	/* list_empty() must return false in rxrpc_notify_socket() */
569	call->recvmsg_link.next = NULL;
570	call->recvmsg_link.prev = NULL;
571
572	spin_unlock(&rx->recvmsg_lock);
573	if (put)
574		rxrpc_put_call(call, rxrpc_call_put_unnotify);
575
576	write_lock(&rx->call_lock);
577
578	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
579		rb_erase(&call->sock_node, &rx->calls);
580		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
581		putu = true;
582	}
583
584	list_del(&call->sock_link);
585	write_unlock(&rx->call_lock);
586
587	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
588
589	if (putu)
590		rxrpc_put_call(call, rxrpc_call_put_userid);
591
592	_leave("");
593}
594
595/*
596 * release all the calls associated with a socket
597 */
598void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
599{
600	struct rxrpc_call *call;
601
602	_enter("%p", rx);
603
604	while (!list_empty(&rx->to_be_accepted)) {
605		call = list_entry(rx->to_be_accepted.next,
606				  struct rxrpc_call, accept_link);
607		list_del(&call->accept_link);
608		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
609				    rxrpc_abort_call_sock_release_tba);
610		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
611	}
612
613	while (!list_empty(&rx->sock_calls)) {
614		call = list_entry(rx->sock_calls.next,
615				  struct rxrpc_call, sock_link);
616		rxrpc_get_call(call, rxrpc_call_get_release_sock);
617		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
618				    rxrpc_abort_call_sock_release);
619		rxrpc_release_call(rx, call);
620		rxrpc_put_call(call, rxrpc_call_put_release_sock);
621	}
622
623	_leave("");
624}
625
626/*
627 * release a call
628 */
629void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
630{
631	struct rxrpc_net *rxnet = call->rxnet;
632	unsigned int debug_id = call->debug_id;
633	bool dead;
634	int r;
635
636	ASSERT(call != NULL);
637
638	dead = __refcount_dec_and_test(&call->ref, &r);
639	trace_rxrpc_call(debug_id, r - 1, 0, why);
640	if (dead) {
641		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
642
643		if (!list_empty(&call->link)) {
644			spin_lock(&rxnet->call_lock);
645			list_del_init(&call->link);
646			spin_unlock(&rxnet->call_lock);
647		}
648
649		rxrpc_cleanup_call(call);
650	}
651}
652
653/*
654 * Free up the call under RCU.
655 */
656static void rxrpc_rcu_free_call(struct rcu_head *rcu)
657{
658	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
659	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
660
661	kmem_cache_free(rxrpc_call_jar, call);
662	if (atomic_dec_and_test(&rxnet->nr_calls))
663		wake_up_var(&rxnet->nr_calls);
664}
665
666/*
667 * Final call destruction - but must be done in process context.
668 */
669static void rxrpc_destroy_call(struct work_struct *work)
670{
671	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
672	struct rxrpc_txbuf *txb;
673
674	del_timer_sync(&call->timer);
675
676	rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack);
677	rxrpc_cleanup_ring(call);
678	while ((txb = list_first_entry_or_null(&call->tx_sendmsg,
679					       struct rxrpc_txbuf, call_link))) {
680		list_del(&txb->call_link);
681		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
682	}
683	while ((txb = list_first_entry_or_null(&call->tx_buffer,
684					       struct rxrpc_txbuf, call_link))) {
685		list_del(&txb->call_link);
686		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
687	}
688
689	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
690	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
691	rxrpc_deactivate_bundle(call->bundle);
692	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
693	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
694	rxrpc_put_local(call->local, rxrpc_local_put_call);
695	call_rcu(&call->rcu, rxrpc_rcu_free_call);
696}
697
698/*
699 * clean up a call
700 */
701void rxrpc_cleanup_call(struct rxrpc_call *call)
702{
703	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
704
705	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
706	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
707
708	del_timer(&call->timer);
709
710	if (rcu_read_lock_held())
711		/* Can't use the rxrpc workqueue as we need to cancel/flush
712		 * something that may be running/waiting there.
713		 */
714		schedule_work(&call->destroyer);
715	else
716		rxrpc_destroy_call(&call->destroyer);
717}
718
719/*
720 * Make sure that all calls are gone from a network namespace.  To reach this
721 * point, any open UDP sockets in that namespace must have been closed, so any
722 * outstanding calls cannot be doing I/O.
723 */
724void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
725{
726	struct rxrpc_call *call;
727
728	_enter("");
729
730	if (!list_empty(&rxnet->calls)) {
731		spin_lock(&rxnet->call_lock);
732
733		while (!list_empty(&rxnet->calls)) {
734			call = list_entry(rxnet->calls.next,
735					  struct rxrpc_call, link);
736			_debug("Zapping call %p", call);
737
738			rxrpc_see_call(call, rxrpc_call_see_zap);
739			list_del_init(&call->link);
740
741			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
742			       call, refcount_read(&call->ref),
743			       rxrpc_call_states[__rxrpc_call_state(call)],
744			       call->flags, call->events);
745
746			spin_unlock(&rxnet->call_lock);
747			cond_resched();
748			spin_lock(&rxnet->call_lock);
749		}
750
751		spin_unlock(&rxnet->call_lock);
752	}
753
754	atomic_dec(&rxnet->nr_calls);
755	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
756}