Merge tag 'dmaengine-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul...
[platform/kernel/linux-starfive.git] / net / rxrpc / call_object.c
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
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
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
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  */
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  */
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         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  */
195 static 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         ret = rxrpc_init_client_call_security(call);
228         if (ret < 0) {
229                 rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret);
230                 rxrpc_put_call(call, rxrpc_call_put_discard_error);
231                 return ERR_PTR(ret);
232         }
233
234         rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_CONN);
235
236         trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
237                          p->user_call_ID, rxrpc_call_new_client);
238
239         _leave(" = %p", call);
240         return call;
241 }
242
243 /*
244  * Initiate the call ack/resend/expiry timer.
245  */
246 void rxrpc_start_call_timer(struct rxrpc_call *call)
247 {
248         unsigned long now = jiffies;
249         unsigned long j = now + MAX_JIFFY_OFFSET;
250
251         call->delay_ack_at = j;
252         call->ack_lost_at = j;
253         call->resend_at = j;
254         call->ping_at = j;
255         call->keepalive_at = j;
256         call->expect_rx_by = j;
257         call->expect_req_by = j;
258         call->expect_term_by = j;
259         call->timer.expires = now;
260 }
261
262 /*
263  * Wait for a call slot to become available.
264  */
265 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
266 {
267         struct semaphore *limiter = &rxrpc_call_limiter;
268
269         if (p->kernel)
270                 limiter = &rxrpc_kernel_call_limiter;
271         if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
272                 down(limiter);
273                 return limiter;
274         }
275         return down_interruptible(limiter) < 0 ? NULL : limiter;
276 }
277
278 /*
279  * Release a call slot.
280  */
281 static void rxrpc_put_call_slot(struct rxrpc_call *call)
282 {
283         struct semaphore *limiter = &rxrpc_call_limiter;
284
285         if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
286                 limiter = &rxrpc_kernel_call_limiter;
287         up(limiter);
288 }
289
290 /*
291  * Start the process of connecting a call.  We obtain a peer and a connection
292  * bundle, but the actual association of a call with a connection is offloaded
293  * to the I/O thread to simplify locking.
294  */
295 static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
296 {
297         struct rxrpc_local *local = call->local;
298         int ret = -ENOMEM;
299
300         _enter("{%d,%lx},", call->debug_id, call->user_call_ID);
301
302         call->peer = rxrpc_lookup_peer(local, &call->dest_srx, gfp);
303         if (!call->peer)
304                 goto error;
305
306         ret = rxrpc_look_up_bundle(call, gfp);
307         if (ret < 0)
308                 goto error;
309
310         trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
311         rxrpc_get_call(call, rxrpc_call_get_io_thread);
312         spin_lock(&local->client_call_lock);
313         list_add_tail(&call->wait_link, &local->new_client_calls);
314         spin_unlock(&local->client_call_lock);
315         rxrpc_wake_up_io_thread(local);
316         return 0;
317
318 error:
319         __set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
320         return ret;
321 }
322
323 /*
324  * Set up a call for the given parameters.
325  * - Called with the socket lock held, which it must release.
326  * - If it returns a call, the call's lock will need releasing by the caller.
327  */
328 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
329                                          struct rxrpc_conn_parameters *cp,
330                                          struct sockaddr_rxrpc *srx,
331                                          struct rxrpc_call_params *p,
332                                          gfp_t gfp,
333                                          unsigned int debug_id)
334         __releases(&rx->sk.sk_lock.slock)
335         __acquires(&call->user_mutex)
336 {
337         struct rxrpc_call *call, *xcall;
338         struct rxrpc_net *rxnet;
339         struct semaphore *limiter;
340         struct rb_node *parent, **pp;
341         int ret;
342
343         _enter("%p,%lx", rx, p->user_call_ID);
344
345         limiter = rxrpc_get_call_slot(p, gfp);
346         if (!limiter) {
347                 release_sock(&rx->sk);
348                 return ERR_PTR(-ERESTARTSYS);
349         }
350
351         call = rxrpc_alloc_client_call(rx, srx, cp, p, gfp, debug_id);
352         if (IS_ERR(call)) {
353                 release_sock(&rx->sk);
354                 up(limiter);
355                 _leave(" = %ld", PTR_ERR(call));
356                 return call;
357         }
358
359         /* We need to protect a partially set up call against the user as we
360          * will be acting outside the socket lock.
361          */
362         mutex_lock(&call->user_mutex);
363
364         /* Publish the call, even though it is incompletely set up as yet */
365         write_lock(&rx->call_lock);
366
367         pp = &rx->calls.rb_node;
368         parent = NULL;
369         while (*pp) {
370                 parent = *pp;
371                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
372
373                 if (p->user_call_ID < xcall->user_call_ID)
374                         pp = &(*pp)->rb_left;
375                 else if (p->user_call_ID > xcall->user_call_ID)
376                         pp = &(*pp)->rb_right;
377                 else
378                         goto error_dup_user_ID;
379         }
380
381         rcu_assign_pointer(call->socket, rx);
382         call->user_call_ID = p->user_call_ID;
383         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
384         rxrpc_get_call(call, rxrpc_call_get_userid);
385         rb_link_node(&call->sock_node, parent, pp);
386         rb_insert_color(&call->sock_node, &rx->calls);
387         list_add(&call->sock_link, &rx->sock_calls);
388
389         write_unlock(&rx->call_lock);
390
391         rxnet = call->rxnet;
392         spin_lock(&rxnet->call_lock);
393         list_add_tail_rcu(&call->link, &rxnet->calls);
394         spin_unlock(&rxnet->call_lock);
395
396         /* From this point on, the call is protected by its own lock. */
397         release_sock(&rx->sk);
398
399         /* Set up or get a connection record and set the protocol parameters,
400          * including channel number and call ID.
401          */
402         ret = rxrpc_connect_call(call, gfp);
403         if (ret < 0)
404                 goto error_attached_to_socket;
405
406         _leave(" = %p [new]", call);
407         return call;
408
409         /* We unexpectedly found the user ID in the list after taking
410          * the call_lock.  This shouldn't happen unless the user races
411          * with itself and tries to add the same user ID twice at the
412          * same time in different threads.
413          */
414 error_dup_user_ID:
415         write_unlock(&rx->call_lock);
416         release_sock(&rx->sk);
417         rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
418         trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
419                          rxrpc_call_see_userid_exists);
420         mutex_unlock(&call->user_mutex);
421         rxrpc_put_call(call, rxrpc_call_put_userid_exists);
422         _leave(" = -EEXIST");
423         return ERR_PTR(-EEXIST);
424
425         /* We got an error, but the call is attached to the socket and is in
426          * need of release.  However, we might now race with recvmsg() when it
427          * completion notifies the socket.  Return 0 from sys_sendmsg() and
428          * leave the error to recvmsg() to deal with.
429          */
430 error_attached_to_socket:
431         trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
432                          rxrpc_call_see_connect_failed);
433         rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
434         _leave(" = c=%08x [err]", call->debug_id);
435         return call;
436 }
437
438 /*
439  * Set up an incoming call.  call->conn points to the connection.
440  * This is called in BH context and isn't allowed to fail.
441  */
442 void rxrpc_incoming_call(struct rxrpc_sock *rx,
443                          struct rxrpc_call *call,
444                          struct sk_buff *skb)
445 {
446         struct rxrpc_connection *conn = call->conn;
447         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
448         u32 chan;
449
450         _enter(",%d", call->conn->debug_id);
451
452         rcu_assign_pointer(call->socket, rx);
453         call->call_id           = sp->hdr.callNumber;
454         call->dest_srx.srx_service = sp->hdr.serviceId;
455         call->cid               = sp->hdr.cid;
456         call->cong_tstamp       = skb->tstamp;
457
458         __set_bit(RXRPC_CALL_EXPOSED, &call->flags);
459         rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
460
461         spin_lock(&conn->state_lock);
462
463         switch (conn->state) {
464         case RXRPC_CONN_SERVICE_UNSECURED:
465         case RXRPC_CONN_SERVICE_CHALLENGING:
466                 rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SECURING);
467                 break;
468         case RXRPC_CONN_SERVICE:
469                 rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
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  */
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
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  */
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  */
539 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
540 {
541         skb_queue_purge(&call->recvmsg_queue);
542         skb_queue_purge(&call->rx_oos_queue);
543 }
544
545 /*
546  * Detach a call from its owning socket.
547  */
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  */
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  */
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  */
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  */
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_cleanup_ring(call);
682         while ((txb = list_first_entry_or_null(&call->tx_sendmsg,
683                                                struct rxrpc_txbuf, call_link))) {
684                 list_del(&txb->call_link);
685                 rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
686         }
687         while ((txb = list_first_entry_or_null(&call->tx_buffer,
688                                                struct rxrpc_txbuf, call_link))) {
689                 list_del(&txb->call_link);
690                 rxrpc_put_txbuf(txb, rxrpc_txbuf_put_cleaned);
691         }
692
693         rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
694         rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
695         rxrpc_deactivate_bundle(call->bundle);
696         rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
697         rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
698         rxrpc_put_local(call->local, rxrpc_local_put_call);
699         call_rcu(&call->rcu, rxrpc_rcu_free_call);
700 }
701
702 /*
703  * clean up a call
704  */
705 void rxrpc_cleanup_call(struct rxrpc_call *call)
706 {
707         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
708
709         ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
710         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
711
712         del_timer(&call->timer);
713
714         if (rcu_read_lock_held())
715                 /* Can't use the rxrpc workqueue as we need to cancel/flush
716                  * something that may be running/waiting there.
717                  */
718                 schedule_work(&call->destroyer);
719         else
720                 rxrpc_destroy_call(&call->destroyer);
721 }
722
723 /*
724  * Make sure that all calls are gone from a network namespace.  To reach this
725  * point, any open UDP sockets in that namespace must have been closed, so any
726  * outstanding calls cannot be doing I/O.
727  */
728 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
729 {
730         struct rxrpc_call *call;
731
732         _enter("");
733
734         if (!list_empty(&rxnet->calls)) {
735                 spin_lock(&rxnet->call_lock);
736
737                 while (!list_empty(&rxnet->calls)) {
738                         call = list_entry(rxnet->calls.next,
739                                           struct rxrpc_call, link);
740                         _debug("Zapping call %p", call);
741
742                         rxrpc_see_call(call, rxrpc_call_see_zap);
743                         list_del_init(&call->link);
744
745                         pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
746                                call, refcount_read(&call->ref),
747                                rxrpc_call_states[__rxrpc_call_state(call)],
748                                call->flags, call->events);
749
750                         spin_unlock(&rxnet->call_lock);
751                         cond_resched();
752                         spin_lock(&rxnet->call_lock);
753                 }
754
755                 spin_unlock(&rxnet->call_lock);
756         }
757
758         atomic_dec(&rxnet->nr_calls);
759         wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
760 }