xref: /kernel/linux/linux-6.6/net/rxrpc/call_object.c (revision 62306a36)
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, jiffies);
74		rxrpc_poke_call(call, rxrpc_call_poke_timer);
75	}
76}
77
78void 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
87static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
88
89static void rxrpc_destroy_call(struct work_struct *);
90
91/*
92 * find an extant server call
93 * - called in process context with IRQs enabled
94 */
95struct 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
121found_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 */
131struct 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 */
195static 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 */
253void 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 */
272static 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 */
288static 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 */
302static 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
325error:
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 */
335struct 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	 */
421error_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	 */
437error_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 */
449void 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 */
512void 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
521struct 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 */
535void 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 */
546static 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 */
555void 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 */
610void 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 */
641void 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 */
668static 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 */
681static 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 */
713void 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 */
736void 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