xref: /openbmc/linux/net/rxrpc/call_object.c (revision 360823a09426347ea8f232b0b0b5156d0aed0302)
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_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 
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, jiffies);
73 		rxrpc_poke_call(call, rxrpc_call_poke_timer);
74 	}
75 }
76 
rxrpc_reduce_call_timer(struct rxrpc_call * call,unsigned long expire_at,unsigned long now,enum rxrpc_timer_trace why)77 void rxrpc_reduce_call_timer(struct rxrpc_call *call,
78 			     unsigned long expire_at,
79 			     unsigned long now,
80 			     enum rxrpc_timer_trace why)
81 {
82 	trace_rxrpc_timer(call, why, now);
83 	timer_reduce(&call->timer, expire_at);
84 }
85 
86 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
87 
88 static void rxrpc_destroy_call(struct work_struct *);
89 
90 /*
91  * find an extant server call
92  * - called in process context with IRQs enabled
93  */
rxrpc_find_call_by_user_ID(struct rxrpc_sock * rx,unsigned long user_call_ID)94 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
95 					      unsigned long user_call_ID)
96 {
97 	struct rxrpc_call *call;
98 	struct rb_node *p;
99 
100 	_enter("%p,%lx", rx, user_call_ID);
101 
102 	read_lock(&rx->call_lock);
103 
104 	p = rx->calls.rb_node;
105 	while (p) {
106 		call = rb_entry(p, struct rxrpc_call, sock_node);
107 
108 		if (user_call_ID < call->user_call_ID)
109 			p = p->rb_left;
110 		else if (user_call_ID > call->user_call_ID)
111 			p = p->rb_right;
112 		else
113 			goto found_extant_call;
114 	}
115 
116 	read_unlock(&rx->call_lock);
117 	_leave(" = NULL");
118 	return NULL;
119 
120 found_extant_call:
121 	rxrpc_get_call(call, rxrpc_call_get_sendmsg);
122 	read_unlock(&rx->call_lock);
123 	_leave(" = %p [%d]", call, refcount_read(&call->ref));
124 	return call;
125 }
126 
127 /*
128  * allocate a new call
129  */
rxrpc_alloc_call(struct rxrpc_sock * rx,gfp_t gfp,unsigned int debug_id)130 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
131 				    unsigned int debug_id)
132 {
133 	struct rxrpc_call *call;
134 	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
135 
136 	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
137 	if (!call)
138 		return NULL;
139 
140 	mutex_init(&call->user_mutex);
141 
142 	/* Prevent lockdep reporting a deadlock false positive between the afs
143 	 * filesystem and sys_sendmsg() via the mmap sem.
144 	 */
145 	if (rx->sk.sk_kern_sock)
146 		lockdep_set_class(&call->user_mutex,
147 				  &rxrpc_call_user_mutex_lock_class_key);
148 
149 	timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
150 	INIT_WORK(&call->destroyer, rxrpc_destroy_call);
151 	INIT_LIST_HEAD(&call->link);
152 	INIT_LIST_HEAD(&call->wait_link);
153 	INIT_LIST_HEAD(&call->accept_link);
154 	INIT_LIST_HEAD(&call->recvmsg_link);
155 	INIT_LIST_HEAD(&call->sock_link);
156 	INIT_LIST_HEAD(&call->attend_link);
157 	INIT_LIST_HEAD(&call->tx_sendmsg);
158 	INIT_LIST_HEAD(&call->tx_buffer);
159 	skb_queue_head_init(&call->recvmsg_queue);
160 	skb_queue_head_init(&call->rx_oos_queue);
161 	init_waitqueue_head(&call->waitq);
162 	spin_lock_init(&call->notify_lock);
163 	spin_lock_init(&call->tx_lock);
164 	refcount_set(&call->ref, 1);
165 	call->debug_id = debug_id;
166 	call->tx_total_len = -1;
167 	call->next_rx_timo = 20 * HZ;
168 	call->next_req_timo = 1 * HZ;
169 	call->ackr_window = 1;
170 	call->ackr_wtop = 1;
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 	call->cong_cwnd = RXRPC_MIN_CWND;
178 	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
179 
180 	call->rxnet = rxnet;
181 	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
182 	atomic_inc(&rxnet->nr_calls);
183 	return call;
184 }
185 
186 /*
187  * Allocate a new client call.
188  */
rxrpc_alloc_client_call(struct rxrpc_sock * rx,struct sockaddr_rxrpc * srx,struct rxrpc_conn_parameters * cp,struct rxrpc_call_params * p,gfp_t gfp,unsigned int debug_id)189 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
190 						  struct sockaddr_rxrpc *srx,
191 						  struct rxrpc_conn_parameters *cp,
192 						  struct rxrpc_call_params *p,
193 						  gfp_t gfp,
194 						  unsigned int debug_id)
195 {
196 	struct rxrpc_call *call;
197 	ktime_t now;
198 	int ret;
199 
200 	_enter("");
201 
202 	call = rxrpc_alloc_call(rx, gfp, debug_id);
203 	if (!call)
204 		return ERR_PTR(-ENOMEM);
205 	now = ktime_get_real();
206 	call->acks_latest_ts	= now;
207 	call->cong_tstamp	= now;
208 	call->dest_srx		= *srx;
209 	call->interruptibility	= p->interruptibility;
210 	call->tx_total_len	= p->tx_total_len;
211 	call->key		= key_get(cp->key);
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(msecs_to_jiffies(p->timeouts.normal), 1UL);
223 	if (p->timeouts.idle)
224 		call->next_req_timo = min(msecs_to_jiffies(p->timeouts.idle), 1UL);
225 	if (p->timeouts.hard)
226 		call->hard_timo = p->timeouts.hard * HZ;
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 	unsigned long now = jiffies;
250 	unsigned long j = now + MAX_JIFFY_OFFSET;
251 
252 	call->delay_ack_at = j;
253 	call->ack_lost_at = j;
254 	call->resend_at = j;
255 	call->ping_at = j;
256 	call->keepalive_at = j;
257 	call->expect_rx_by = j;
258 	call->expect_req_by = j;
259 	call->expect_term_by = j + call->hard_timo;
260 	call->timer.expires = now;
261 }
262 
263 /*
264  * Wait for a call slot to become available.
265  */
rxrpc_get_call_slot(struct rxrpc_call_params * p,gfp_t gfp)266 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
267 {
268 	struct semaphore *limiter = &rxrpc_call_limiter;
269 
270 	if (p->kernel)
271 		limiter = &rxrpc_kernel_call_limiter;
272 	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
273 		down(limiter);
274 		return limiter;
275 	}
276 	return down_interruptible(limiter) < 0 ? NULL : limiter;
277 }
278 
279 /*
280  * Release a call slot.
281  */
rxrpc_put_call_slot(struct rxrpc_call * call)282 static void rxrpc_put_call_slot(struct rxrpc_call *call)
283 {
284 	struct semaphore *limiter = &rxrpc_call_limiter;
285 
286 	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
287 		limiter = &rxrpc_kernel_call_limiter;
288 	up(limiter);
289 }
290 
291 /*
292  * Start the process of connecting a call.  We obtain a peer and a connection
293  * bundle, but the actual association of a call with a connection is offloaded
294  * to the I/O thread to simplify locking.
295  */
rxrpc_connect_call(struct rxrpc_call * call,gfp_t gfp)296 static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
297 {
298 	struct rxrpc_local *local = call->local;
299 	int ret = -ENOMEM;
300 
301 	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
302 
303 	call->peer = rxrpc_lookup_peer(local, &call->dest_srx, gfp);
304 	if (!call->peer)
305 		goto error;
306 
307 	ret = rxrpc_look_up_bundle(call, gfp);
308 	if (ret < 0)
309 		goto error;
310 
311 	trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
312 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
313 	spin_lock(&local->client_call_lock);
314 	list_add_tail(&call->wait_link, &local->new_client_calls);
315 	spin_unlock(&local->client_call_lock);
316 	rxrpc_wake_up_io_thread(local);
317 	return 0;
318 
319 error:
320 	__set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
321 	return ret;
322 }
323 
324 /*
325  * Set up a call for the given parameters.
326  * - Called with the socket lock held, which it must release.
327  * - If it returns a call, the call's lock will need releasing by the caller.
328  */
rxrpc_new_client_call(struct rxrpc_sock * rx,struct rxrpc_conn_parameters * cp,struct sockaddr_rxrpc * srx,struct rxrpc_call_params * p,gfp_t gfp,unsigned int debug_id)329 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
330 					 struct rxrpc_conn_parameters *cp,
331 					 struct sockaddr_rxrpc *srx,
332 					 struct rxrpc_call_params *p,
333 					 gfp_t gfp,
334 					 unsigned int debug_id)
335 	__releases(&rx->sk.sk_lock.slock)
336 	__acquires(&call->user_mutex)
337 {
338 	struct rxrpc_call *call, *xcall;
339 	struct rxrpc_net *rxnet;
340 	struct semaphore *limiter;
341 	struct rb_node *parent, **pp;
342 	int ret;
343 
344 	_enter("%p,%lx", rx, p->user_call_ID);
345 
346 	limiter = rxrpc_get_call_slot(p, gfp);
347 	if (!limiter) {
348 		release_sock(&rx->sk);
349 		return ERR_PTR(-ERESTARTSYS);
350 	}
351 
352 	call = rxrpc_alloc_client_call(rx, srx, cp, p, gfp, debug_id);
353 	if (IS_ERR(call)) {
354 		release_sock(&rx->sk);
355 		up(limiter);
356 		_leave(" = %ld", PTR_ERR(call));
357 		return call;
358 	}
359 
360 	/* We need to protect a partially set up call against the user as we
361 	 * will be acting outside the socket lock.
362 	 */
363 	mutex_lock(&call->user_mutex);
364 
365 	/* Publish the call, even though it is incompletely set up as yet */
366 	write_lock(&rx->call_lock);
367 
368 	pp = &rx->calls.rb_node;
369 	parent = NULL;
370 	while (*pp) {
371 		parent = *pp;
372 		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
373 
374 		if (p->user_call_ID < xcall->user_call_ID)
375 			pp = &(*pp)->rb_left;
376 		else if (p->user_call_ID > xcall->user_call_ID)
377 			pp = &(*pp)->rb_right;
378 		else
379 			goto error_dup_user_ID;
380 	}
381 
382 	rcu_assign_pointer(call->socket, rx);
383 	call->user_call_ID = p->user_call_ID;
384 	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
385 	rxrpc_get_call(call, rxrpc_call_get_userid);
386 	rb_link_node(&call->sock_node, parent, pp);
387 	rb_insert_color(&call->sock_node, &rx->calls);
388 	list_add(&call->sock_link, &rx->sock_calls);
389 
390 	write_unlock(&rx->call_lock);
391 
392 	rxnet = call->rxnet;
393 	spin_lock(&rxnet->call_lock);
394 	list_add_tail_rcu(&call->link, &rxnet->calls);
395 	spin_unlock(&rxnet->call_lock);
396 
397 	/* From this point on, the call is protected by its own lock. */
398 	release_sock(&rx->sk);
399 
400 	/* Set up or get a connection record and set the protocol parameters,
401 	 * including channel number and call ID.
402 	 */
403 	ret = rxrpc_connect_call(call, gfp);
404 	if (ret < 0)
405 		goto error_attached_to_socket;
406 
407 	_leave(" = %p [new]", call);
408 	return call;
409 
410 	/* We unexpectedly found the user ID in the list after taking
411 	 * the call_lock.  This shouldn't happen unless the user races
412 	 * with itself and tries to add the same user ID twice at the
413 	 * same time in different threads.
414 	 */
415 error_dup_user_ID:
416 	write_unlock(&rx->call_lock);
417 	release_sock(&rx->sk);
418 	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
419 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
420 			 rxrpc_call_see_userid_exists);
421 	mutex_unlock(&call->user_mutex);
422 	rxrpc_put_call(call, rxrpc_call_put_userid_exists);
423 	_leave(" = -EEXIST");
424 	return ERR_PTR(-EEXIST);
425 
426 	/* We got an error, but the call is attached to the socket and is in
427 	 * need of release.  However, we might now race with recvmsg() when it
428 	 * completion notifies the socket.  Return 0 from sys_sendmsg() and
429 	 * leave the error to recvmsg() to deal with.
430 	 */
431 error_attached_to_socket:
432 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
433 			 rxrpc_call_see_connect_failed);
434 	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
435 	_leave(" = c=%08x [err]", call->debug_id);
436 	return call;
437 }
438 
439 /*
440  * Set up an incoming call.  call->conn points to the connection.
441  * This is called in BH context and isn't allowed to fail.
442  */
rxrpc_incoming_call(struct rxrpc_sock * rx,struct rxrpc_call * call,struct sk_buff * skb)443 void rxrpc_incoming_call(struct rxrpc_sock *rx,
444 			 struct rxrpc_call *call,
445 			 struct sk_buff *skb)
446 {
447 	struct rxrpc_connection *conn = call->conn;
448 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
449 	u32 chan;
450 
451 	_enter(",%d", call->conn->debug_id);
452 
453 	rcu_assign_pointer(call->socket, rx);
454 	call->call_id		= sp->hdr.callNumber;
455 	call->dest_srx.srx_service = sp->hdr.serviceId;
456 	call->cid		= sp->hdr.cid;
457 	call->cong_tstamp	= skb->tstamp;
458 
459 	__set_bit(RXRPC_CALL_EXPOSED, &call->flags);
460 	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
461 
462 	spin_lock(&conn->state_lock);
463 
464 	switch (conn->state) {
465 	case RXRPC_CONN_SERVICE_UNSECURED:
466 	case RXRPC_CONN_SERVICE_CHALLENGING:
467 		__set_bit(RXRPC_CALL_CONN_CHALLENGING, &call->flags);
468 		break;
469 	case RXRPC_CONN_SERVICE:
470 		break;
471 
472 	case RXRPC_CONN_ABORTED:
473 		rxrpc_set_call_completion(call, conn->completion,
474 					  conn->abort_code, conn->error);
475 		break;
476 	default:
477 		BUG();
478 	}
479 
480 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
481 
482 	/* Set the channel for this call.  We don't get channel_lock as we're
483 	 * only defending against the data_ready handler (which we're called
484 	 * from) and the RESPONSE packet parser (which is only really
485 	 * interested in call_counter and can cope with a disagreement with the
486 	 * call pointer).
487 	 */
488 	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
489 	conn->channels[chan].call_counter = call->call_id;
490 	conn->channels[chan].call_id = call->call_id;
491 	conn->channels[chan].call = call;
492 	spin_unlock(&conn->state_lock);
493 
494 	spin_lock(&conn->peer->lock);
495 	hlist_add_head(&call->error_link, &conn->peer->error_targets);
496 	spin_unlock(&conn->peer->lock);
497 
498 	rxrpc_start_call_timer(call);
499 	_leave("");
500 }
501 
502 /*
503  * Note the re-emergence of a call.
504  */
rxrpc_see_call(struct rxrpc_call * call,enum rxrpc_call_trace why)505 void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
506 {
507 	if (call) {
508 		int r = refcount_read(&call->ref);
509 
510 		trace_rxrpc_call(call->debug_id, r, 0, why);
511 	}
512 }
513 
rxrpc_try_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)514 struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call,
515 				      enum rxrpc_call_trace why)
516 {
517 	int r;
518 
519 	if (!call || !__refcount_inc_not_zero(&call->ref, &r))
520 		return NULL;
521 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
522 	return call;
523 }
524 
525 /*
526  * Note the addition of a ref on a call.
527  */
rxrpc_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)528 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
529 {
530 	int r;
531 
532 	__refcount_inc(&call->ref, &r);
533 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
534 }
535 
536 /*
537  * Clean up the Rx skb ring.
538  */
rxrpc_cleanup_ring(struct rxrpc_call * call)539 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
540 {
541 	rxrpc_purge_queue(&call->recvmsg_queue);
542 	rxrpc_purge_queue(&call->rx_oos_queue);
543 }
544 
545 /*
546  * Detach a call from its owning socket.
547  */
rxrpc_release_call(struct rxrpc_sock * rx,struct rxrpc_call * call)548 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
549 {
550 	struct rxrpc_connection *conn = call->conn;
551 	bool put = false, putu = false;
552 
553 	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
554 
555 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
556 			 call->flags, rxrpc_call_see_release);
557 
558 	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
559 		BUG();
560 
561 	rxrpc_put_call_slot(call);
562 
563 	/* Make sure we don't get any more notifications */
564 	spin_lock(&rx->recvmsg_lock);
565 
566 	if (!list_empty(&call->recvmsg_link)) {
567 		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
568 		       call, call->events, call->flags);
569 		list_del(&call->recvmsg_link);
570 		put = true;
571 	}
572 
573 	/* list_empty() must return false in rxrpc_notify_socket() */
574 	call->recvmsg_link.next = NULL;
575 	call->recvmsg_link.prev = NULL;
576 
577 	spin_unlock(&rx->recvmsg_lock);
578 	if (put)
579 		rxrpc_put_call(call, rxrpc_call_put_unnotify);
580 
581 	write_lock(&rx->call_lock);
582 
583 	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
584 		rb_erase(&call->sock_node, &rx->calls);
585 		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
586 		putu = true;
587 	}
588 
589 	list_del(&call->sock_link);
590 	write_unlock(&rx->call_lock);
591 
592 	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
593 
594 	if (putu)
595 		rxrpc_put_call(call, rxrpc_call_put_userid);
596 
597 	_leave("");
598 }
599 
600 /*
601  * release all the calls associated with a socket
602  */
rxrpc_release_calls_on_socket(struct rxrpc_sock * rx)603 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
604 {
605 	struct rxrpc_call *call;
606 
607 	_enter("%p", rx);
608 
609 	while (!list_empty(&rx->to_be_accepted)) {
610 		call = list_entry(rx->to_be_accepted.next,
611 				  struct rxrpc_call, accept_link);
612 		list_del(&call->accept_link);
613 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
614 				    rxrpc_abort_call_sock_release_tba);
615 		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
616 	}
617 
618 	while (!list_empty(&rx->sock_calls)) {
619 		call = list_entry(rx->sock_calls.next,
620 				  struct rxrpc_call, sock_link);
621 		rxrpc_get_call(call, rxrpc_call_get_release_sock);
622 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
623 				    rxrpc_abort_call_sock_release);
624 		rxrpc_release_call(rx, call);
625 		rxrpc_put_call(call, rxrpc_call_put_release_sock);
626 	}
627 
628 	_leave("");
629 }
630 
631 /*
632  * release a call
633  */
rxrpc_put_call(struct rxrpc_call * call,enum rxrpc_call_trace why)634 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
635 {
636 	struct rxrpc_net *rxnet = call->rxnet;
637 	unsigned int debug_id = call->debug_id;
638 	bool dead;
639 	int r;
640 
641 	ASSERT(call != NULL);
642 
643 	dead = __refcount_dec_and_test(&call->ref, &r);
644 	trace_rxrpc_call(debug_id, r - 1, 0, why);
645 	if (dead) {
646 		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
647 
648 		if (!list_empty(&call->link)) {
649 			spin_lock(&rxnet->call_lock);
650 			list_del_init(&call->link);
651 			spin_unlock(&rxnet->call_lock);
652 		}
653 
654 		rxrpc_cleanup_call(call);
655 	}
656 }
657 
658 /*
659  * Free up the call under RCU.
660  */
rxrpc_rcu_free_call(struct rcu_head * rcu)661 static void rxrpc_rcu_free_call(struct rcu_head *rcu)
662 {
663 	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
664 	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
665 
666 	kmem_cache_free(rxrpc_call_jar, call);
667 	if (atomic_dec_and_test(&rxnet->nr_calls))
668 		wake_up_var(&rxnet->nr_calls);
669 }
670 
671 /*
672  * Final call destruction - but must be done in process context.
673  */
rxrpc_destroy_call(struct work_struct * work)674 static void rxrpc_destroy_call(struct work_struct *work)
675 {
676 	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
677 	struct rxrpc_txbuf *txb;
678 
679 	del_timer_sync(&call->timer);
680 
681 	rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack);
682 	rxrpc_cleanup_ring(call);
683 	while ((txb = list_first_entry_or_null(&call->tx_sendmsg,
684 					       struct rxrpc_txbuf, call_link))) {
685 		list_del(&txb->call_link);
686 		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
687 	}
688 	while ((txb = list_first_entry_or_null(&call->tx_buffer,
689 					       struct rxrpc_txbuf, call_link))) {
690 		list_del(&txb->call_link);
691 		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
692 	}
693 
694 	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
695 	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
696 	rxrpc_deactivate_bundle(call->bundle);
697 	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
698 	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
699 	rxrpc_put_local(call->local, rxrpc_local_put_call);
700 	call_rcu(&call->rcu, rxrpc_rcu_free_call);
701 }
702 
703 /*
704  * clean up a call
705  */
rxrpc_cleanup_call(struct rxrpc_call * call)706 void rxrpc_cleanup_call(struct rxrpc_call *call)
707 {
708 	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
709 
710 	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
711 	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
712 
713 	del_timer(&call->timer);
714 
715 	if (rcu_read_lock_held())
716 		/* Can't use the rxrpc workqueue as we need to cancel/flush
717 		 * something that may be running/waiting there.
718 		 */
719 		schedule_work(&call->destroyer);
720 	else
721 		rxrpc_destroy_call(&call->destroyer);
722 }
723 
724 /*
725  * Make sure that all calls are gone from a network namespace.  To reach this
726  * point, any open UDP sockets in that namespace must have been closed, so any
727  * outstanding calls cannot be doing I/O.
728  */
rxrpc_destroy_all_calls(struct rxrpc_net * rxnet)729 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
730 {
731 	struct rxrpc_call *call;
732 
733 	_enter("");
734 
735 	if (!list_empty(&rxnet->calls)) {
736 		spin_lock(&rxnet->call_lock);
737 
738 		while (!list_empty(&rxnet->calls)) {
739 			call = list_entry(rxnet->calls.next,
740 					  struct rxrpc_call, link);
741 			_debug("Zapping call %p", call);
742 
743 			rxrpc_see_call(call, rxrpc_call_see_zap);
744 			list_del_init(&call->link);
745 
746 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
747 			       call, refcount_read(&call->ref),
748 			       rxrpc_call_states[__rxrpc_call_state(call)],
749 			       call->flags, call->events);
750 
751 			spin_unlock(&rxnet->call_lock);
752 			cond_resched();
753 			spin_lock(&rxnet->call_lock);
754 		}
755 
756 		spin_unlock(&rxnet->call_lock);
757 	}
758 
759 	atomic_dec(&rxnet->nr_calls);
760 	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
761 }
762