xref: /linux/net/rxrpc/call_object.c (revision 3cf0a98fea776adb09087e521fe150c295a4b031)
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_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 
32 const 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 
40 struct kmem_cache *rxrpc_call_jar;
41 
42 static DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000);
43 static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000);
44 
rxrpc_poke_call(struct rxrpc_call * call,enum rxrpc_call_poke_trace what)45 void 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_irq(&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_irq(&local->lock);
60 		if (!busy)
61 			rxrpc_wake_up_io_thread(local);
62 	}
63 }
64 
rxrpc_call_timer_expired(struct timer_list * t)65 static 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 
77 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
78 
79 static void rxrpc_destroy_call(struct work_struct *);
80 
81 /*
82  * find an extant server call
83  * - called in process context with IRQs enabled
84  */
rxrpc_find_call_by_user_ID(struct rxrpc_sock * rx,unsigned long user_call_ID)85 struct 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 
111 found_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  */
rxrpc_alloc_call(struct rxrpc_sock * rx,gfp_t gfp,unsigned int debug_id)121 struct 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 	skb_queue_head_init(&call->rx_queue);
149 	skb_queue_head_init(&call->recvmsg_queue);
150 	skb_queue_head_init(&call->rx_oos_queue);
151 	init_waitqueue_head(&call->waitq);
152 	spin_lock_init(&call->notify_lock);
153 	refcount_set(&call->ref, 1);
154 	call->debug_id		= debug_id;
155 	call->tx_total_len	= -1;
156 	call->tx_jumbo_max	= 1;
157 	call->next_rx_timo	= 20 * HZ;
158 	call->next_req_timo	= 1 * HZ;
159 	call->ackr_window	= 1;
160 	call->ackr_wtop		= 1;
161 	call->delay_ack_at	= KTIME_MAX;
162 	call->rack_timo_at	= KTIME_MAX;
163 	call->ping_at		= KTIME_MAX;
164 	call->keepalive_at	= KTIME_MAX;
165 	call->expect_rx_by	= KTIME_MAX;
166 	call->expect_req_by	= KTIME_MAX;
167 	call->expect_term_by	= KTIME_MAX;
168 
169 	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
170 
171 	call->rx_winsize = rxrpc_rx_window_size;
172 	call->tx_winsize = 16;
173 
174 	call->cong_cwnd = RXRPC_MIN_CWND;
175 	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
176 
177 	rxrpc_call_init_rtt(call);
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  */
rxrpc_alloc_client_call(struct rxrpc_sock * rx,struct rxrpc_conn_parameters * cp,struct rxrpc_call_params * p,gfp_t gfp,unsigned int debug_id)188 static 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 = umin(p->timeouts.normal, 1);
223 	if (p->timeouts.idle)
224 		call->next_req_timo = umin(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  */
rxrpc_start_call_timer(struct rxrpc_call * call)247 void 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  */
rxrpc_get_call_slot(struct rxrpc_call_params * p,gfp_t gfp)261 static 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  */
rxrpc_put_call_slot(struct rxrpc_call * call)277 static 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  */
rxrpc_connect_call(struct rxrpc_call * call,gfp_t gfp)291 static 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_irq(&local->client_call_lock);
305 	list_add_tail(&call->wait_link, &local->new_client_calls);
306 	spin_unlock_irq(&local->client_call_lock);
307 	rxrpc_wake_up_io_thread(local);
308 	return 0;
309 
310 error:
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  */
rxrpc_new_client_call(struct rxrpc_sock * rx,struct rxrpc_conn_parameters * cp,struct rxrpc_call_params * p,gfp_t gfp,unsigned int debug_id)320 struct 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 	 */
410 error_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 	 */
426 error_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 with interrupts disabled and isn't allowed to fail.
437  */
rxrpc_incoming_call(struct rxrpc_sock * rx,struct rxrpc_call * call,struct sk_buff * skb)438 void 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  */
rxrpc_see_call(struct rxrpc_call * call,enum rxrpc_call_trace why)500 void 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 
rxrpc_try_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)509 struct 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  */
rxrpc_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)523 void 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 transmission buffers.
533  */
rxrpc_cleanup_tx_buffers(struct rxrpc_call * call)534 static void rxrpc_cleanup_tx_buffers(struct rxrpc_call *call)
535 {
536 	struct rxrpc_txqueue *tq, *next;
537 
538 	for (tq = call->tx_queue; tq; tq = next) {
539 		next = tq->next;
540 		for (int i = 0; i < RXRPC_NR_TXQUEUE; i++)
541 			if (tq->bufs[i])
542 				rxrpc_put_txbuf(tq->bufs[i], rxrpc_txbuf_put_cleaned);
543 		trace_rxrpc_tq(call, tq, 0, rxrpc_tq_cleaned);
544 		kfree(tq);
545 	}
546 }
547 
548 /*
549  * Clean up the receive buffers.
550  */
rxrpc_cleanup_rx_buffers(struct rxrpc_call * call)551 static void rxrpc_cleanup_rx_buffers(struct rxrpc_call *call)
552 {
553 	rxrpc_purge_queue(&call->recvmsg_queue);
554 	rxrpc_purge_queue(&call->rx_queue);
555 	rxrpc_purge_queue(&call->rx_oos_queue);
556 }
557 
558 /*
559  * Detach a call from its owning socket.
560  */
rxrpc_release_call(struct rxrpc_sock * rx,struct rxrpc_call * call)561 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
562 {
563 	struct rxrpc_connection *conn = call->conn;
564 	bool put = false, putu = false;
565 
566 	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
567 
568 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
569 			 call->flags, rxrpc_call_see_release);
570 
571 	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
572 		BUG();
573 
574 	rxrpc_put_call_slot(call);
575 
576 	/* Make sure we don't get any more notifications */
577 	spin_lock_irq(&rx->recvmsg_lock);
578 
579 	if (!list_empty(&call->recvmsg_link)) {
580 		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
581 		       call, call->events, call->flags);
582 		list_del(&call->recvmsg_link);
583 		put = true;
584 	}
585 
586 	/* list_empty() must return false in rxrpc_notify_socket() */
587 	call->recvmsg_link.next = NULL;
588 	call->recvmsg_link.prev = NULL;
589 
590 	spin_unlock_irq(&rx->recvmsg_lock);
591 	if (put)
592 		rxrpc_put_call(call, rxrpc_call_put_unnotify);
593 
594 	write_lock(&rx->call_lock);
595 
596 	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
597 		rb_erase(&call->sock_node, &rx->calls);
598 		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
599 		putu = true;
600 	}
601 
602 	list_del(&call->sock_link);
603 	write_unlock(&rx->call_lock);
604 
605 	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
606 
607 	if (putu)
608 		rxrpc_put_call(call, rxrpc_call_put_userid);
609 
610 	_leave("");
611 }
612 
613 /*
614  * release all the calls associated with a socket
615  */
rxrpc_release_calls_on_socket(struct rxrpc_sock * rx)616 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
617 {
618 	struct rxrpc_call *call;
619 
620 	_enter("%p", rx);
621 
622 	while (!list_empty(&rx->to_be_accepted)) {
623 		call = list_entry(rx->to_be_accepted.next,
624 				  struct rxrpc_call, accept_link);
625 		list_del(&call->accept_link);
626 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
627 				    rxrpc_abort_call_sock_release_tba);
628 		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
629 	}
630 
631 	while (!list_empty(&rx->sock_calls)) {
632 		call = list_entry(rx->sock_calls.next,
633 				  struct rxrpc_call, sock_link);
634 		rxrpc_get_call(call, rxrpc_call_get_release_sock);
635 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
636 				    rxrpc_abort_call_sock_release);
637 		rxrpc_release_call(rx, call);
638 		rxrpc_put_call(call, rxrpc_call_put_release_sock);
639 	}
640 
641 	_leave("");
642 }
643 
644 /*
645  * release a call
646  */
rxrpc_put_call(struct rxrpc_call * call,enum rxrpc_call_trace why)647 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
648 {
649 	struct rxrpc_net *rxnet = call->rxnet;
650 	unsigned int debug_id = call->debug_id;
651 	bool dead;
652 	int r;
653 
654 	ASSERT(call != NULL);
655 
656 	dead = __refcount_dec_and_test(&call->ref, &r);
657 	trace_rxrpc_call(debug_id, r - 1, 0, why);
658 	if (dead) {
659 		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
660 
661 		if (!list_empty(&call->link)) {
662 			spin_lock(&rxnet->call_lock);
663 			list_del_init(&call->link);
664 			spin_unlock(&rxnet->call_lock);
665 		}
666 
667 		rxrpc_cleanup_call(call);
668 	}
669 }
670 
671 /*
672  * Free up the call under RCU.
673  */
rxrpc_rcu_free_call(struct rcu_head * rcu)674 static void rxrpc_rcu_free_call(struct rcu_head *rcu)
675 {
676 	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
677 	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
678 
679 	kmem_cache_free(rxrpc_call_jar, call);
680 	if (atomic_dec_and_test(&rxnet->nr_calls))
681 		wake_up_var(&rxnet->nr_calls);
682 }
683 
684 /*
685  * Final call destruction - but must be done in process context.
686  */
rxrpc_destroy_call(struct work_struct * work)687 static void rxrpc_destroy_call(struct work_struct *work)
688 {
689 	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
690 
691 	del_timer_sync(&call->timer);
692 
693 	rxrpc_cleanup_tx_buffers(call);
694 	rxrpc_cleanup_rx_buffers(call);
695 	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
696 	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
697 	rxrpc_deactivate_bundle(call->bundle);
698 	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
699 	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
700 	rxrpc_put_local(call->local, rxrpc_local_put_call);
701 	call_rcu(&call->rcu, rxrpc_rcu_free_call);
702 }
703 
704 /*
705  * clean up a call
706  */
rxrpc_cleanup_call(struct rxrpc_call * call)707 void rxrpc_cleanup_call(struct rxrpc_call *call)
708 {
709 	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
710 
711 	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
712 	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
713 
714 	del_timer(&call->timer);
715 
716 	if (rcu_read_lock_held())
717 		/* Can't use the rxrpc workqueue as we need to cancel/flush
718 		 * something that may be running/waiting there.
719 		 */
720 		schedule_work(&call->destroyer);
721 	else
722 		rxrpc_destroy_call(&call->destroyer);
723 }
724 
725 /*
726  * Make sure that all calls are gone from a network namespace.  To reach this
727  * point, any open UDP sockets in that namespace must have been closed, so any
728  * outstanding calls cannot be doing I/O.
729  */
rxrpc_destroy_all_calls(struct rxrpc_net * rxnet)730 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
731 {
732 	struct rxrpc_call *call;
733 
734 	_enter("");
735 
736 	if (!list_empty(&rxnet->calls)) {
737 		spin_lock(&rxnet->call_lock);
738 
739 		while (!list_empty(&rxnet->calls)) {
740 			call = list_entry(rxnet->calls.next,
741 					  struct rxrpc_call, link);
742 			_debug("Zapping call %p", call);
743 
744 			rxrpc_see_call(call, rxrpc_call_see_zap);
745 			list_del_init(&call->link);
746 
747 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
748 			       call, refcount_read(&call->ref),
749 			       rxrpc_call_states[__rxrpc_call_state(call)],
750 			       call->flags, call->events);
751 
752 			spin_unlock(&rxnet->call_lock);
753 			cond_resched();
754 			spin_lock(&rxnet->call_lock);
755 		}
756 
757 		spin_unlock(&rxnet->call_lock);
758 	}
759 
760 	atomic_dec(&rxnet->nr_calls);
761 	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
762 }
763