xref: /openbmc/linux/net/rxrpc/call_object.c (revision fa6dbe25)
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_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 
33 const 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 
41 struct kmem_cache *rxrpc_call_jar;
42 
43 static DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000);
44 static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000);
45 
rxrpc_poke_call(struct rxrpc_call * call,enum rxrpc_call_poke_trace what)46 void 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 
rxrpc_call_timer_expired(struct timer_list * t)66 static 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 
rxrpc_reduce_call_timer(struct rxrpc_call * call,unsigned long expire_at,unsigned long now,enum rxrpc_timer_trace why)78 void 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 
87 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
88 
89 static void rxrpc_destroy_call(struct work_struct *);
90 
91 /*
92  * find an extant server call
93  * - called in process context with IRQs enabled
94  */
rxrpc_find_call_by_user_ID(struct rxrpc_sock * rx,unsigned long user_call_ID)95 struct 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 
121 found_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  */
rxrpc_alloc_call(struct rxrpc_sock * rx,gfp_t gfp,unsigned int debug_id)131 struct 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 	call->cong_cwnd = RXRPC_MIN_CWND;
179 	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
180 
181 	call->rxnet = rxnet;
182 	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
183 	atomic_inc(&rxnet->nr_calls);
184 	return call;
185 }
186 
187 /*
188  * Allocate a new client call.
189  */
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)190 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
191 						  struct sockaddr_rxrpc *srx,
192 						  struct rxrpc_conn_parameters *cp,
193 						  struct rxrpc_call_params *p,
194 						  gfp_t gfp,
195 						  unsigned int debug_id)
196 {
197 	struct rxrpc_call *call;
198 	ktime_t now;
199 	int ret;
200 
201 	_enter("");
202 
203 	call = rxrpc_alloc_call(rx, gfp, debug_id);
204 	if (!call)
205 		return ERR_PTR(-ENOMEM);
206 	now = ktime_get_real();
207 	call->acks_latest_ts	= now;
208 	call->cong_tstamp	= now;
209 	call->dest_srx		= *srx;
210 	call->interruptibility	= p->interruptibility;
211 	call->tx_total_len	= p->tx_total_len;
212 	call->key		= key_get(cp->key);
213 	call->local		= rxrpc_get_local(cp->local, rxrpc_local_get_call);
214 	call->security_level	= cp->security_level;
215 	if (p->kernel)
216 		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
217 	if (cp->upgrade)
218 		__set_bit(RXRPC_CALL_UPGRADE, &call->flags);
219 	if (cp->exclusive)
220 		__set_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
221 
222 	if (p->timeouts.normal)
223 		call->next_rx_timo = min(msecs_to_jiffies(p->timeouts.normal), 1UL);
224 	if (p->timeouts.idle)
225 		call->next_req_timo = min(msecs_to_jiffies(p->timeouts.idle), 1UL);
226 	if (p->timeouts.hard)
227 		call->hard_timo = p->timeouts.hard * HZ;
228 
229 	ret = rxrpc_init_client_call_security(call);
230 	if (ret < 0) {
231 		rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret);
232 		rxrpc_put_call(call, rxrpc_call_put_discard_error);
233 		return ERR_PTR(ret);
234 	}
235 
236 	rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_CONN);
237 
238 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
239 			 p->user_call_ID, rxrpc_call_new_client);
240 
241 	_leave(" = %p", call);
242 	return call;
243 }
244 
245 /*
246  * Initiate the call ack/resend/expiry timer.
247  */
rxrpc_start_call_timer(struct rxrpc_call * call)248 void rxrpc_start_call_timer(struct rxrpc_call *call)
249 {
250 	unsigned long now = jiffies;
251 	unsigned long j = now + MAX_JIFFY_OFFSET;
252 
253 	call->delay_ack_at = j;
254 	call->ack_lost_at = j;
255 	call->resend_at = j;
256 	call->ping_at = j;
257 	call->keepalive_at = j;
258 	call->expect_rx_by = j;
259 	call->expect_req_by = j;
260 	call->expect_term_by = j + call->hard_timo;
261 	call->timer.expires = now;
262 }
263 
264 /*
265  * Wait for a call slot to become available.
266  */
rxrpc_get_call_slot(struct rxrpc_call_params * p,gfp_t gfp)267 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
268 {
269 	struct semaphore *limiter = &rxrpc_call_limiter;
270 
271 	if (p->kernel)
272 		limiter = &rxrpc_kernel_call_limiter;
273 	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
274 		down(limiter);
275 		return limiter;
276 	}
277 	return down_interruptible(limiter) < 0 ? NULL : limiter;
278 }
279 
280 /*
281  * Release a call slot.
282  */
rxrpc_put_call_slot(struct rxrpc_call * call)283 static void rxrpc_put_call_slot(struct rxrpc_call *call)
284 {
285 	struct semaphore *limiter = &rxrpc_call_limiter;
286 
287 	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
288 		limiter = &rxrpc_kernel_call_limiter;
289 	up(limiter);
290 }
291 
292 /*
293  * Start the process of connecting a call.  We obtain a peer and a connection
294  * bundle, but the actual association of a call with a connection is offloaded
295  * to the I/O thread to simplify locking.
296  */
rxrpc_connect_call(struct rxrpc_call * call,gfp_t gfp)297 static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
298 {
299 	struct rxrpc_local *local = call->local;
300 	int ret = -ENOMEM;
301 
302 	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
303 
304 	call->peer = rxrpc_lookup_peer(local, &call->dest_srx, gfp);
305 	if (!call->peer)
306 		goto error;
307 
308 	ret = rxrpc_look_up_bundle(call, gfp);
309 	if (ret < 0)
310 		goto error;
311 
312 	trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
313 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
314 	spin_lock(&local->client_call_lock);
315 	list_add_tail(&call->wait_link, &local->new_client_calls);
316 	spin_unlock(&local->client_call_lock);
317 	rxrpc_wake_up_io_thread(local);
318 	return 0;
319 
320 error:
321 	__set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
322 	return ret;
323 }
324 
325 /*
326  * Set up a call for the given parameters.
327  * - Called with the socket lock held, which it must release.
328  * - If it returns a call, the call's lock will need releasing by the caller.
329  */
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)330 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
331 					 struct rxrpc_conn_parameters *cp,
332 					 struct sockaddr_rxrpc *srx,
333 					 struct rxrpc_call_params *p,
334 					 gfp_t gfp,
335 					 unsigned int debug_id)
336 	__releases(&rx->sk.sk_lock.slock)
337 	__acquires(&call->user_mutex)
338 {
339 	struct rxrpc_call *call, *xcall;
340 	struct rxrpc_net *rxnet;
341 	struct semaphore *limiter;
342 	struct rb_node *parent, **pp;
343 	int ret;
344 
345 	_enter("%p,%lx", rx, p->user_call_ID);
346 
347 	limiter = rxrpc_get_call_slot(p, gfp);
348 	if (!limiter) {
349 		release_sock(&rx->sk);
350 		return ERR_PTR(-ERESTARTSYS);
351 	}
352 
353 	call = rxrpc_alloc_client_call(rx, srx, cp, p, gfp, debug_id);
354 	if (IS_ERR(call)) {
355 		release_sock(&rx->sk);
356 		up(limiter);
357 		_leave(" = %ld", PTR_ERR(call));
358 		return call;
359 	}
360 
361 	/* We need to protect a partially set up call against the user as we
362 	 * will be acting outside the socket lock.
363 	 */
364 	mutex_lock(&call->user_mutex);
365 
366 	/* Publish the call, even though it is incompletely set up as yet */
367 	write_lock(&rx->call_lock);
368 
369 	pp = &rx->calls.rb_node;
370 	parent = NULL;
371 	while (*pp) {
372 		parent = *pp;
373 		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
374 
375 		if (p->user_call_ID < xcall->user_call_ID)
376 			pp = &(*pp)->rb_left;
377 		else if (p->user_call_ID > xcall->user_call_ID)
378 			pp = &(*pp)->rb_right;
379 		else
380 			goto error_dup_user_ID;
381 	}
382 
383 	rcu_assign_pointer(call->socket, rx);
384 	call->user_call_ID = p->user_call_ID;
385 	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
386 	rxrpc_get_call(call, rxrpc_call_get_userid);
387 	rb_link_node(&call->sock_node, parent, pp);
388 	rb_insert_color(&call->sock_node, &rx->calls);
389 	list_add(&call->sock_link, &rx->sock_calls);
390 
391 	write_unlock(&rx->call_lock);
392 
393 	rxnet = call->rxnet;
394 	spin_lock(&rxnet->call_lock);
395 	list_add_tail_rcu(&call->link, &rxnet->calls);
396 	spin_unlock(&rxnet->call_lock);
397 
398 	/* From this point on, the call is protected by its own lock. */
399 	release_sock(&rx->sk);
400 
401 	/* Set up or get a connection record and set the protocol parameters,
402 	 * including channel number and call ID.
403 	 */
404 	ret = rxrpc_connect_call(call, gfp);
405 	if (ret < 0)
406 		goto error_attached_to_socket;
407 
408 	_leave(" = %p [new]", call);
409 	return call;
410 
411 	/* We unexpectedly found the user ID in the list after taking
412 	 * the call_lock.  This shouldn't happen unless the user races
413 	 * with itself and tries to add the same user ID twice at the
414 	 * same time in different threads.
415 	 */
416 error_dup_user_ID:
417 	write_unlock(&rx->call_lock);
418 	release_sock(&rx->sk);
419 	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
420 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
421 			 rxrpc_call_see_userid_exists);
422 	mutex_unlock(&call->user_mutex);
423 	rxrpc_put_call(call, rxrpc_call_put_userid_exists);
424 	_leave(" = -EEXIST");
425 	return ERR_PTR(-EEXIST);
426 
427 	/* We got an error, but the call is attached to the socket and is in
428 	 * need of release.  However, we might now race with recvmsg() when it
429 	 * completion notifies the socket.  Return 0 from sys_sendmsg() and
430 	 * leave the error to recvmsg() to deal with.
431 	 */
432 error_attached_to_socket:
433 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
434 			 rxrpc_call_see_connect_failed);
435 	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
436 	_leave(" = c=%08x [err]", call->debug_id);
437 	return call;
438 }
439 
440 /*
441  * Set up an incoming call.  call->conn points to the connection.
442  * This is called in BH context and isn't allowed to fail.
443  */
rxrpc_incoming_call(struct rxrpc_sock * rx,struct rxrpc_call * call,struct sk_buff * skb)444 void rxrpc_incoming_call(struct rxrpc_sock *rx,
445 			 struct rxrpc_call *call,
446 			 struct sk_buff *skb)
447 {
448 	struct rxrpc_connection *conn = call->conn;
449 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
450 	u32 chan;
451 
452 	_enter(",%d", call->conn->debug_id);
453 
454 	rcu_assign_pointer(call->socket, rx);
455 	call->call_id		= sp->hdr.callNumber;
456 	call->dest_srx.srx_service = sp->hdr.serviceId;
457 	call->cid		= sp->hdr.cid;
458 	call->cong_tstamp	= skb->tstamp;
459 
460 	__set_bit(RXRPC_CALL_EXPOSED, &call->flags);
461 	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
462 
463 	spin_lock(&conn->state_lock);
464 
465 	switch (conn->state) {
466 	case RXRPC_CONN_SERVICE_UNSECURED:
467 	case RXRPC_CONN_SERVICE_CHALLENGING:
468 		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
469 		break;
470 	case RXRPC_CONN_SERVICE:
471 		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
472 		break;
473 
474 	case RXRPC_CONN_ABORTED:
475 		rxrpc_set_call_completion(call, conn->completion,
476 					  conn->abort_code, conn->error);
477 		break;
478 	default:
479 		BUG();
480 	}
481 
482 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
483 
484 	/* Set the channel for this call.  We don't get channel_lock as we're
485 	 * only defending against the data_ready handler (which we're called
486 	 * from) and the RESPONSE packet parser (which is only really
487 	 * interested in call_counter and can cope with a disagreement with the
488 	 * call pointer).
489 	 */
490 	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
491 	conn->channels[chan].call_counter = call->call_id;
492 	conn->channels[chan].call_id = call->call_id;
493 	conn->channels[chan].call = call;
494 	spin_unlock(&conn->state_lock);
495 
496 	spin_lock(&conn->peer->lock);
497 	hlist_add_head(&call->error_link, &conn->peer->error_targets);
498 	spin_unlock(&conn->peer->lock);
499 
500 	rxrpc_start_call_timer(call);
501 	_leave("");
502 }
503 
504 /*
505  * Note the re-emergence of a call.
506  */
rxrpc_see_call(struct rxrpc_call * call,enum rxrpc_call_trace why)507 void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
508 {
509 	if (call) {
510 		int r = refcount_read(&call->ref);
511 
512 		trace_rxrpc_call(call->debug_id, r, 0, why);
513 	}
514 }
515 
rxrpc_try_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)516 struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call,
517 				      enum rxrpc_call_trace why)
518 {
519 	int r;
520 
521 	if (!call || !__refcount_inc_not_zero(&call->ref, &r))
522 		return NULL;
523 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
524 	return call;
525 }
526 
527 /*
528  * Note the addition of a ref on a call.
529  */
rxrpc_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)530 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
531 {
532 	int r;
533 
534 	__refcount_inc(&call->ref, &r);
535 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
536 }
537 
538 /*
539  * Clean up the Rx skb ring.
540  */
rxrpc_cleanup_ring(struct rxrpc_call * call)541 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
542 {
543 	rxrpc_purge_queue(&call->recvmsg_queue);
544 	rxrpc_purge_queue(&call->rx_oos_queue);
545 }
546 
547 /*
548  * Detach a call from its owning socket.
549  */
rxrpc_release_call(struct rxrpc_sock * rx,struct rxrpc_call * call)550 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
551 {
552 	struct rxrpc_connection *conn = call->conn;
553 	bool put = false, putu = false;
554 
555 	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
556 
557 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
558 			 call->flags, rxrpc_call_see_release);
559 
560 	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
561 		BUG();
562 
563 	rxrpc_put_call_slot(call);
564 
565 	/* Make sure we don't get any more notifications */
566 	spin_lock(&rx->recvmsg_lock);
567 
568 	if (!list_empty(&call->recvmsg_link)) {
569 		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
570 		       call, call->events, call->flags);
571 		list_del(&call->recvmsg_link);
572 		put = true;
573 	}
574 
575 	/* list_empty() must return false in rxrpc_notify_socket() */
576 	call->recvmsg_link.next = NULL;
577 	call->recvmsg_link.prev = NULL;
578 
579 	spin_unlock(&rx->recvmsg_lock);
580 	if (put)
581 		rxrpc_put_call(call, rxrpc_call_put_unnotify);
582 
583 	write_lock(&rx->call_lock);
584 
585 	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
586 		rb_erase(&call->sock_node, &rx->calls);
587 		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
588 		putu = true;
589 	}
590 
591 	list_del(&call->sock_link);
592 	write_unlock(&rx->call_lock);
593 
594 	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
595 
596 	if (putu)
597 		rxrpc_put_call(call, rxrpc_call_put_userid);
598 
599 	_leave("");
600 }
601 
602 /*
603  * release all the calls associated with a socket
604  */
rxrpc_release_calls_on_socket(struct rxrpc_sock * rx)605 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
606 {
607 	struct rxrpc_call *call;
608 
609 	_enter("%p", rx);
610 
611 	while (!list_empty(&rx->to_be_accepted)) {
612 		call = list_entry(rx->to_be_accepted.next,
613 				  struct rxrpc_call, accept_link);
614 		list_del(&call->accept_link);
615 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
616 				    rxrpc_abort_call_sock_release_tba);
617 		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
618 	}
619 
620 	while (!list_empty(&rx->sock_calls)) {
621 		call = list_entry(rx->sock_calls.next,
622 				  struct rxrpc_call, sock_link);
623 		rxrpc_get_call(call, rxrpc_call_get_release_sock);
624 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
625 				    rxrpc_abort_call_sock_release);
626 		rxrpc_release_call(rx, call);
627 		rxrpc_put_call(call, rxrpc_call_put_release_sock);
628 	}
629 
630 	_leave("");
631 }
632 
633 /*
634  * release a call
635  */
rxrpc_put_call(struct rxrpc_call * call,enum rxrpc_call_trace why)636 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
637 {
638 	struct rxrpc_net *rxnet = call->rxnet;
639 	unsigned int debug_id = call->debug_id;
640 	bool dead;
641 	int r;
642 
643 	ASSERT(call != NULL);
644 
645 	dead = __refcount_dec_and_test(&call->ref, &r);
646 	trace_rxrpc_call(debug_id, r - 1, 0, why);
647 	if (dead) {
648 		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
649 
650 		if (!list_empty(&call->link)) {
651 			spin_lock(&rxnet->call_lock);
652 			list_del_init(&call->link);
653 			spin_unlock(&rxnet->call_lock);
654 		}
655 
656 		rxrpc_cleanup_call(call);
657 	}
658 }
659 
660 /*
661  * Free up the call under RCU.
662  */
rxrpc_rcu_free_call(struct rcu_head * rcu)663 static void rxrpc_rcu_free_call(struct rcu_head *rcu)
664 {
665 	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
666 	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
667 
668 	kmem_cache_free(rxrpc_call_jar, call);
669 	if (atomic_dec_and_test(&rxnet->nr_calls))
670 		wake_up_var(&rxnet->nr_calls);
671 }
672 
673 /*
674  * Final call destruction - but must be done in process context.
675  */
rxrpc_destroy_call(struct work_struct * work)676 static void rxrpc_destroy_call(struct work_struct *work)
677 {
678 	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
679 	struct rxrpc_txbuf *txb;
680 
681 	del_timer_sync(&call->timer);
682 
683 	rxrpc_free_skb(call->cong_last_nack, rxrpc_skb_put_last_nack);
684 	rxrpc_cleanup_ring(call);
685 	while ((txb = list_first_entry_or_null(&call->tx_sendmsg,
686 					       struct rxrpc_txbuf, call_link))) {
687 		list_del(&txb->call_link);
688 		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
689 	}
690 	while ((txb = list_first_entry_or_null(&call->tx_buffer,
691 					       struct rxrpc_txbuf, call_link))) {
692 		list_del(&txb->call_link);
693 		rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
694 	}
695 
696 	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
697 	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
698 	rxrpc_deactivate_bundle(call->bundle);
699 	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
700 	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
701 	rxrpc_put_local(call->local, rxrpc_local_put_call);
702 	call_rcu(&call->rcu, rxrpc_rcu_free_call);
703 }
704 
705 /*
706  * clean up a call
707  */
rxrpc_cleanup_call(struct rxrpc_call * call)708 void rxrpc_cleanup_call(struct rxrpc_call *call)
709 {
710 	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
711 
712 	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
713 	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
714 
715 	del_timer(&call->timer);
716 
717 	if (rcu_read_lock_held())
718 		/* Can't use the rxrpc workqueue as we need to cancel/flush
719 		 * something that may be running/waiting there.
720 		 */
721 		schedule_work(&call->destroyer);
722 	else
723 		rxrpc_destroy_call(&call->destroyer);
724 }
725 
726 /*
727  * Make sure that all calls are gone from a network namespace.  To reach this
728  * point, any open UDP sockets in that namespace must have been closed, so any
729  * outstanding calls cannot be doing I/O.
730  */
rxrpc_destroy_all_calls(struct rxrpc_net * rxnet)731 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
732 {
733 	struct rxrpc_call *call;
734 
735 	_enter("");
736 
737 	if (!list_empty(&rxnet->calls)) {
738 		spin_lock(&rxnet->call_lock);
739 
740 		while (!list_empty(&rxnet->calls)) {
741 			call = list_entry(rxnet->calls.next,
742 					  struct rxrpc_call, link);
743 			_debug("Zapping call %p", call);
744 
745 			rxrpc_see_call(call, rxrpc_call_see_zap);
746 			list_del_init(&call->link);
747 
748 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
749 			       call, refcount_read(&call->ref),
750 			       rxrpc_call_states[__rxrpc_call_state(call)],
751 			       call->flags, call->events);
752 
753 			spin_unlock(&rxnet->call_lock);
754 			cond_resched();
755 			spin_lock(&rxnet->call_lock);
756 		}
757 
758 		spin_unlock(&rxnet->call_lock);
759 	}
760 
761 	atomic_dec(&rxnet->nr_calls);
762 	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
763 }
764