RxRPC: Use uX/sX rather than uintX_t/intX_t types
[linux-2.6.git] / net / rxrpc / ar-ack.c
1 /* Management of Tx window, Tx resend, ACKs and out-of-sequence reception
2  *
3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11
12 #include <linux/module.h>
13 #include <linux/circ_buf.h>
14 #include <linux/net.h>
15 #include <linux/skbuff.h>
16 #include <linux/udp.h>
17 #include <net/sock.h>
18 #include <net/af_rxrpc.h>
19 #include "ar-internal.h"
20
21 static unsigned rxrpc_ack_defer = 1;
22
23 static const char *const rxrpc_acks[] = {
24         "---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY", "IDL",
25         "-?-"
26 };
27
28 static const s8 rxrpc_ack_priority[] = {
29         [0]                             = 0,
30         [RXRPC_ACK_DELAY]               = 1,
31         [RXRPC_ACK_REQUESTED]           = 2,
32         [RXRPC_ACK_IDLE]                = 3,
33         [RXRPC_ACK_PING_RESPONSE]       = 4,
34         [RXRPC_ACK_DUPLICATE]           = 5,
35         [RXRPC_ACK_OUT_OF_SEQUENCE]     = 6,
36         [RXRPC_ACK_EXCEEDS_WINDOW]      = 7,
37         [RXRPC_ACK_NOSPACE]             = 8,
38 };
39
40 /*
41  * propose an ACK be sent
42  */
43 void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
44                          __be32 serial, bool immediate)
45 {
46         unsigned long expiry;
47         s8 prior = rxrpc_ack_priority[ack_reason];
48
49         ASSERTCMP(prior, >, 0);
50
51         _enter("{%d},%s,%%%x,%u",
52                call->debug_id, rxrpc_acks[ack_reason], ntohl(serial),
53                immediate);
54
55         if (prior < rxrpc_ack_priority[call->ackr_reason]) {
56                 if (immediate)
57                         goto cancel_timer;
58                 return;
59         }
60
61         /* update DELAY, IDLE, REQUESTED and PING_RESPONSE ACK serial
62          * numbers */
63         if (prior == rxrpc_ack_priority[call->ackr_reason]) {
64                 if (prior <= 4)
65                         call->ackr_serial = serial;
66                 if (immediate)
67                         goto cancel_timer;
68                 return;
69         }
70
71         call->ackr_reason = ack_reason;
72         call->ackr_serial = serial;
73
74         switch (ack_reason) {
75         case RXRPC_ACK_DELAY:
76                 _debug("run delay timer");
77                 call->ack_timer.expires = jiffies + rxrpc_ack_timeout * HZ;
78                 add_timer(&call->ack_timer);
79                 return;
80
81         case RXRPC_ACK_IDLE:
82                 if (!immediate) {
83                         _debug("run defer timer");
84                         expiry = 1;
85                         goto run_timer;
86                 }
87                 goto cancel_timer;
88
89         case RXRPC_ACK_REQUESTED:
90                 if (!rxrpc_ack_defer)
91                         goto cancel_timer;
92                 if (!immediate || serial == cpu_to_be32(1)) {
93                         _debug("run defer timer");
94                         expiry = rxrpc_ack_defer;
95                         goto run_timer;
96                 }
97
98         default:
99                 _debug("immediate ACK");
100                 goto cancel_timer;
101         }
102
103 run_timer:
104         expiry += jiffies;
105         if (!timer_pending(&call->ack_timer) ||
106             time_after(call->ack_timer.expires, expiry))
107                 mod_timer(&call->ack_timer, expiry);
108         return;
109
110 cancel_timer:
111         _debug("cancel timer %%%u", ntohl(serial));
112         try_to_del_timer_sync(&call->ack_timer);
113         read_lock_bh(&call->state_lock);
114         if (call->state <= RXRPC_CALL_COMPLETE &&
115             !test_and_set_bit(RXRPC_CALL_ACK, &call->events))
116                 rxrpc_queue_call(call);
117         read_unlock_bh(&call->state_lock);
118 }
119
120 /*
121  * propose an ACK be sent, locking the call structure
122  */
123 void rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
124                        __be32 serial, bool immediate)
125 {
126         s8 prior = rxrpc_ack_priority[ack_reason];
127
128         if (prior > rxrpc_ack_priority[call->ackr_reason]) {
129                 spin_lock_bh(&call->lock);
130                 __rxrpc_propose_ACK(call, ack_reason, serial, immediate);
131                 spin_unlock_bh(&call->lock);
132         }
133 }
134
135 /*
136  * set the resend timer
137  */
138 static void rxrpc_set_resend(struct rxrpc_call *call, u8 resend,
139                              unsigned long resend_at)
140 {
141         read_lock_bh(&call->state_lock);
142         if (call->state >= RXRPC_CALL_COMPLETE)
143                 resend = 0;
144
145         if (resend & 1) {
146                 _debug("SET RESEND");
147                 set_bit(RXRPC_CALL_RESEND, &call->events);
148         }
149
150         if (resend & 2) {
151                 _debug("MODIFY RESEND TIMER");
152                 set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
153                 mod_timer(&call->resend_timer, resend_at);
154         } else {
155                 _debug("KILL RESEND TIMER");
156                 del_timer_sync(&call->resend_timer);
157                 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
158                 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
159         }
160         read_unlock_bh(&call->state_lock);
161 }
162
163 /*
164  * resend packets
165  */
166 static void rxrpc_resend(struct rxrpc_call *call)
167 {
168         struct rxrpc_skb_priv *sp;
169         struct rxrpc_header *hdr;
170         struct sk_buff *txb;
171         unsigned long *p_txb, resend_at;
172         int loop, stop;
173         u8 resend;
174
175         _enter("{%d,%d,%d,%d},",
176                call->acks_hard, call->acks_unacked,
177                atomic_read(&call->sequence),
178                CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
179
180         stop = 0;
181         resend = 0;
182         resend_at = 0;
183
184         for (loop = call->acks_tail;
185              loop != call->acks_head || stop;
186              loop = (loop + 1) &  (call->acks_winsz - 1)
187              ) {
188                 p_txb = call->acks_window + loop;
189                 smp_read_barrier_depends();
190                 if (*p_txb & 1)
191                         continue;
192
193                 txb = (struct sk_buff *) *p_txb;
194                 sp = rxrpc_skb(txb);
195
196                 if (sp->need_resend) {
197                         sp->need_resend = 0;
198
199                         /* each Tx packet has a new serial number */
200                         sp->hdr.serial =
201                                 htonl(atomic_inc_return(&call->conn->serial));
202
203                         hdr = (struct rxrpc_header *) txb->head;
204                         hdr->serial = sp->hdr.serial;
205
206                         _proto("Tx DATA %%%u { #%d }",
207                                ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
208                         if (rxrpc_send_packet(call->conn->trans, txb) < 0) {
209                                 stop = 0;
210                                 sp->resend_at = jiffies + 3;
211                         } else {
212                                 sp->resend_at =
213                                         jiffies + rxrpc_resend_timeout * HZ;
214                         }
215                 }
216
217                 if (time_after_eq(jiffies + 1, sp->resend_at)) {
218                         sp->need_resend = 1;
219                         resend |= 1;
220                 } else if (resend & 2) {
221                         if (time_before(sp->resend_at, resend_at))
222                                 resend_at = sp->resend_at;
223                 } else {
224                         resend_at = sp->resend_at;
225                         resend |= 2;
226                 }
227         }
228
229         rxrpc_set_resend(call, resend, resend_at);
230         _leave("");
231 }
232
233 /*
234  * handle resend timer expiry
235  */
236 static void rxrpc_resend_timer(struct rxrpc_call *call)
237 {
238         struct rxrpc_skb_priv *sp;
239         struct sk_buff *txb;
240         unsigned long *p_txb, resend_at;
241         int loop;
242         u8 resend;
243
244         _enter("%d,%d,%d",
245                call->acks_tail, call->acks_unacked, call->acks_head);
246
247         resend = 0;
248         resend_at = 0;
249
250         for (loop = call->acks_unacked;
251              loop != call->acks_head;
252              loop = (loop + 1) &  (call->acks_winsz - 1)
253              ) {
254                 p_txb = call->acks_window + loop;
255                 smp_read_barrier_depends();
256                 txb = (struct sk_buff *) (*p_txb & ~1);
257                 sp = rxrpc_skb(txb);
258
259                 ASSERT(!(*p_txb & 1));
260
261                 if (sp->need_resend) {
262                         ;
263                 } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
264                         sp->need_resend = 1;
265                         resend |= 1;
266                 } else if (resend & 2) {
267                         if (time_before(sp->resend_at, resend_at))
268                                 resend_at = sp->resend_at;
269                 } else {
270                         resend_at = sp->resend_at;
271                         resend |= 2;
272                 }
273         }
274
275         rxrpc_set_resend(call, resend, resend_at);
276         _leave("");
277 }
278
279 /*
280  * process soft ACKs of our transmitted packets
281  * - these indicate packets the peer has or has not received, but hasn't yet
282  *   given to the consumer, and so can still be discarded and re-requested
283  */
284 static int rxrpc_process_soft_ACKs(struct rxrpc_call *call,
285                                    struct rxrpc_ackpacket *ack,
286                                    struct sk_buff *skb)
287 {
288         struct rxrpc_skb_priv *sp;
289         struct sk_buff *txb;
290         unsigned long *p_txb, resend_at;
291         int loop;
292         u8 sacks[RXRPC_MAXACKS], resend;
293
294         _enter("{%d,%d},{%d},",
295                call->acks_hard,
296                CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz),
297                ack->nAcks);
298
299         if (skb_copy_bits(skb, 0, sacks, ack->nAcks) < 0)
300                 goto protocol_error;
301
302         resend = 0;
303         resend_at = 0;
304         for (loop = 0; loop < ack->nAcks; loop++) {
305                 p_txb = call->acks_window;
306                 p_txb += (call->acks_tail + loop) & (call->acks_winsz - 1);
307                 smp_read_barrier_depends();
308                 txb = (struct sk_buff *) (*p_txb & ~1);
309                 sp = rxrpc_skb(txb);
310
311                 switch (sacks[loop]) {
312                 case RXRPC_ACK_TYPE_ACK:
313                         sp->need_resend = 0;
314                         *p_txb |= 1;
315                         break;
316                 case RXRPC_ACK_TYPE_NACK:
317                         sp->need_resend = 1;
318                         *p_txb &= ~1;
319                         resend = 1;
320                         break;
321                 default:
322                         _debug("Unsupported ACK type %d", sacks[loop]);
323                         goto protocol_error;
324                 }
325         }
326
327         smp_mb();
328         call->acks_unacked = (call->acks_tail + loop) & (call->acks_winsz - 1);
329
330         /* anything not explicitly ACK'd is implicitly NACK'd, but may just not
331          * have been received or processed yet by the far end */
332         for (loop = call->acks_unacked;
333              loop != call->acks_head;
334              loop = (loop + 1) &  (call->acks_winsz - 1)
335              ) {
336                 p_txb = call->acks_window + loop;
337                 smp_read_barrier_depends();
338                 txb = (struct sk_buff *) (*p_txb & ~1);
339                 sp = rxrpc_skb(txb);
340
341                 if (*p_txb & 1) {
342                         /* packet must have been discarded */
343                         sp->need_resend = 1;
344                         *p_txb &= ~1;
345                         resend |= 1;
346                 } else if (sp->need_resend) {
347                         ;
348                 } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
349                         sp->need_resend = 1;
350                         resend |= 1;
351                 } else if (resend & 2) {
352                         if (time_before(sp->resend_at, resend_at))
353                                 resend_at = sp->resend_at;
354                 } else {
355                         resend_at = sp->resend_at;
356                         resend |= 2;
357                 }
358         }
359
360         rxrpc_set_resend(call, resend, resend_at);
361         _leave(" = 0");
362         return 0;
363
364 protocol_error:
365         _leave(" = -EPROTO");
366         return -EPROTO;
367 }
368
369 /*
370  * discard hard-ACK'd packets from the Tx window
371  */
372 static void rxrpc_rotate_tx_window(struct rxrpc_call *call, u32 hard)
373 {
374         struct rxrpc_skb_priv *sp;
375         unsigned long _skb;
376         int tail = call->acks_tail, old_tail;
377         int win = CIRC_CNT(call->acks_head, tail, call->acks_winsz);
378
379         _enter("{%u,%u},%u", call->acks_hard, win, hard);
380
381         ASSERTCMP(hard - call->acks_hard, <=, win);
382
383         while (call->acks_hard < hard) {
384                 smp_read_barrier_depends();
385                 _skb = call->acks_window[tail] & ~1;
386                 sp = rxrpc_skb((struct sk_buff *) _skb);
387                 rxrpc_free_skb((struct sk_buff *) _skb);
388                 old_tail = tail;
389                 tail = (tail + 1) & (call->acks_winsz - 1);
390                 call->acks_tail = tail;
391                 if (call->acks_unacked == old_tail)
392                         call->acks_unacked = tail;
393                 call->acks_hard++;
394         }
395
396         wake_up(&call->tx_waitq);
397 }
398
399 /*
400  * clear the Tx window in the event of a failure
401  */
402 static void rxrpc_clear_tx_window(struct rxrpc_call *call)
403 {
404         rxrpc_rotate_tx_window(call, atomic_read(&call->sequence));
405 }
406
407 /*
408  * drain the out of sequence received packet queue into the packet Rx queue
409  */
410 static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call)
411 {
412         struct rxrpc_skb_priv *sp;
413         struct sk_buff *skb;
414         bool terminal;
415         int ret;
416
417         _enter("{%d,%d}", call->rx_data_post, call->rx_first_oos);
418
419         spin_lock_bh(&call->lock);
420
421         ret = -ECONNRESET;
422         if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
423                 goto socket_unavailable;
424
425         skb = skb_dequeue(&call->rx_oos_queue);
426         if (skb) {
427                 sp = rxrpc_skb(skb);
428
429                 _debug("drain OOS packet %d [%d]",
430                        ntohl(sp->hdr.seq), call->rx_first_oos);
431
432                 if (ntohl(sp->hdr.seq) != call->rx_first_oos) {
433                         skb_queue_head(&call->rx_oos_queue, skb);
434                         call->rx_first_oos = ntohl(rxrpc_skb(skb)->hdr.seq);
435                         _debug("requeue %p {%u}", skb, call->rx_first_oos);
436                 } else {
437                         skb->mark = RXRPC_SKB_MARK_DATA;
438                         terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
439                                 !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
440                         ret = rxrpc_queue_rcv_skb(call, skb, true, terminal);
441                         BUG_ON(ret < 0);
442                         _debug("drain #%u", call->rx_data_post);
443                         call->rx_data_post++;
444
445                         /* find out what the next packet is */
446                         skb = skb_peek(&call->rx_oos_queue);
447                         if (skb)
448                                 call->rx_first_oos =
449                                         ntohl(rxrpc_skb(skb)->hdr.seq);
450                         else
451                                 call->rx_first_oos = 0;
452                         _debug("peek %p {%u}", skb, call->rx_first_oos);
453                 }
454         }
455
456         ret = 0;
457 socket_unavailable:
458         spin_unlock_bh(&call->lock);
459         _leave(" = %d", ret);
460         return ret;
461 }
462
463 /*
464  * insert an out of sequence packet into the buffer
465  */
466 static void rxrpc_insert_oos_packet(struct rxrpc_call *call,
467                                     struct sk_buff *skb)
468 {
469         struct rxrpc_skb_priv *sp, *psp;
470         struct sk_buff *p;
471         u32 seq;
472
473         sp = rxrpc_skb(skb);
474         seq = ntohl(sp->hdr.seq);
475         _enter(",,{%u}", seq);
476
477         skb->destructor = rxrpc_packet_destructor;
478         ASSERTCMP(sp->call, ==, NULL);
479         sp->call = call;
480         rxrpc_get_call(call);
481
482         /* insert into the buffer in sequence order */
483         spin_lock_bh(&call->lock);
484
485         skb_queue_walk(&call->rx_oos_queue, p) {
486                 psp = rxrpc_skb(p);
487                 if (ntohl(psp->hdr.seq) > seq) {
488                         _debug("insert oos #%u before #%u",
489                                seq, ntohl(psp->hdr.seq));
490                         skb_insert(p, skb, &call->rx_oos_queue);
491                         goto inserted;
492                 }
493         }
494
495         _debug("append oos #%u", seq);
496         skb_queue_tail(&call->rx_oos_queue, skb);
497 inserted:
498
499         /* we might now have a new front to the queue */
500         if (call->rx_first_oos == 0 || seq < call->rx_first_oos)
501                 call->rx_first_oos = seq;
502
503         read_lock(&call->state_lock);
504         if (call->state < RXRPC_CALL_COMPLETE &&
505             call->rx_data_post == call->rx_first_oos) {
506                 _debug("drain rx oos now");
507                 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
508         }
509         read_unlock(&call->state_lock);
510
511         spin_unlock_bh(&call->lock);
512         _leave(" [stored #%u]", call->rx_first_oos);
513 }
514
515 /*
516  * clear the Tx window on final ACK reception
517  */
518 static void rxrpc_zap_tx_window(struct rxrpc_call *call)
519 {
520         struct rxrpc_skb_priv *sp;
521         struct sk_buff *skb;
522         unsigned long _skb, *acks_window;
523         u8 winsz = call->acks_winsz;
524         int tail;
525
526         acks_window = call->acks_window;
527         call->acks_window = NULL;
528
529         while (CIRC_CNT(call->acks_head, call->acks_tail, winsz) > 0) {
530                 tail = call->acks_tail;
531                 smp_read_barrier_depends();
532                 _skb = acks_window[tail] & ~1;
533                 smp_mb();
534                 call->acks_tail = (call->acks_tail + 1) & (winsz - 1);
535
536                 skb = (struct sk_buff *) _skb;
537                 sp = rxrpc_skb(skb);
538                 _debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
539                 rxrpc_free_skb(skb);
540         }
541
542         kfree(acks_window);
543 }
544
545 /*
546  * process the extra information that may be appended to an ACK packet
547  */
548 static void rxrpc_extract_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
549                                   unsigned latest, int nAcks)
550 {
551         struct rxrpc_ackinfo ackinfo;
552         struct rxrpc_peer *peer;
553         unsigned mtu;
554
555         if (skb_copy_bits(skb, nAcks + 3, &ackinfo, sizeof(ackinfo)) < 0) {
556                 _leave(" [no ackinfo]");
557                 return;
558         }
559
560         _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
561                latest,
562                ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU),
563                ntohl(ackinfo.rwind), ntohl(ackinfo.jumbo_max));
564
565         mtu = min(ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU));
566
567         peer = call->conn->trans->peer;
568         if (mtu < peer->maxdata) {
569                 spin_lock_bh(&peer->lock);
570                 peer->maxdata = mtu;
571                 peer->mtu = mtu + peer->hdrsize;
572                 spin_unlock_bh(&peer->lock);
573                 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
574         }
575 }
576
577 /*
578  * process packets in the reception queue
579  */
580 static int rxrpc_process_rx_queue(struct rxrpc_call *call,
581                                   u32 *_abort_code)
582 {
583         struct rxrpc_ackpacket ack;
584         struct rxrpc_skb_priv *sp;
585         struct sk_buff *skb;
586         bool post_ACK;
587         int latest;
588         u32 hard, tx;
589
590         _enter("");
591
592 process_further:
593         skb = skb_dequeue(&call->rx_queue);
594         if (!skb)
595                 return -EAGAIN;
596
597         _net("deferred skb %p", skb);
598
599         sp = rxrpc_skb(skb);
600
601         _debug("process %s [st %d]", rxrpc_pkts[sp->hdr.type], call->state);
602
603         post_ACK = false;
604
605         switch (sp->hdr.type) {
606                 /* data packets that wind up here have been received out of
607                  * order, need security processing or are jumbo packets */
608         case RXRPC_PACKET_TYPE_DATA:
609                 _proto("OOSQ DATA %%%u { #%u }",
610                        ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
611
612                 /* secured packets must be verified and possibly decrypted */
613                 if (rxrpc_verify_packet(call, skb, _abort_code) < 0)
614                         goto protocol_error;
615
616                 rxrpc_insert_oos_packet(call, skb);
617                 goto process_further;
618
619                 /* partial ACK to process */
620         case RXRPC_PACKET_TYPE_ACK:
621                 if (skb_copy_bits(skb, 0, &ack, sizeof(ack)) < 0) {
622                         _debug("extraction failure");
623                         goto protocol_error;
624                 }
625                 if (!skb_pull(skb, sizeof(ack)))
626                         BUG();
627
628                 latest = ntohl(sp->hdr.serial);
629                 hard = ntohl(ack.firstPacket);
630                 tx = atomic_read(&call->sequence);
631
632                 _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
633                        latest,
634                        ntohs(ack.maxSkew),
635                        hard,
636                        ntohl(ack.previousPacket),
637                        ntohl(ack.serial),
638                        rxrpc_acks[ack.reason],
639                        ack.nAcks);
640
641                 rxrpc_extract_ackinfo(call, skb, latest, ack.nAcks);
642
643                 if (ack.reason == RXRPC_ACK_PING) {
644                         _proto("Rx ACK %%%u PING Request", latest);
645                         rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
646                                           sp->hdr.serial, true);
647                 }
648
649                 /* discard any out-of-order or duplicate ACKs */
650                 if (latest - call->acks_latest <= 0) {
651                         _debug("discard ACK %d <= %d",
652                                latest, call->acks_latest);
653                         goto discard;
654                 }
655                 call->acks_latest = latest;
656
657                 if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
658                     call->state != RXRPC_CALL_CLIENT_AWAIT_REPLY &&
659                     call->state != RXRPC_CALL_SERVER_SEND_REPLY &&
660                     call->state != RXRPC_CALL_SERVER_AWAIT_ACK)
661                         goto discard;
662
663                 _debug("Tx=%d H=%u S=%d", tx, call->acks_hard, call->state);
664
665                 if (hard > 0) {
666                         if (hard - 1 > tx) {
667                                 _debug("hard-ACK'd packet %d not transmitted"
668                                        " (%d top)",
669                                        hard - 1, tx);
670                                 goto protocol_error;
671                         }
672
673                         if ((call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY ||
674                              call->state == RXRPC_CALL_SERVER_AWAIT_ACK) &&
675                             hard > tx)
676                                 goto all_acked;
677
678                         smp_rmb();
679                         rxrpc_rotate_tx_window(call, hard - 1);
680                 }
681
682                 if (ack.nAcks > 0) {
683                         if (hard - 1 + ack.nAcks > tx) {
684                                 _debug("soft-ACK'd packet %d+%d not"
685                                        " transmitted (%d top)",
686                                        hard - 1, ack.nAcks, tx);
687                                 goto protocol_error;
688                         }
689
690                         if (rxrpc_process_soft_ACKs(call, &ack, skb) < 0)
691                                 goto protocol_error;
692                 }
693                 goto discard;
694
695                 /* complete ACK to process */
696         case RXRPC_PACKET_TYPE_ACKALL:
697                 goto all_acked;
698
699                 /* abort and busy are handled elsewhere */
700         case RXRPC_PACKET_TYPE_BUSY:
701         case RXRPC_PACKET_TYPE_ABORT:
702                 BUG();
703
704                 /* connection level events - also handled elsewhere */
705         case RXRPC_PACKET_TYPE_CHALLENGE:
706         case RXRPC_PACKET_TYPE_RESPONSE:
707         case RXRPC_PACKET_TYPE_DEBUG:
708                 BUG();
709         }
710
711         /* if we've had a hard ACK that covers all the packets we've sent, then
712          * that ends that phase of the operation */
713 all_acked:
714         write_lock_bh(&call->state_lock);
715         _debug("ack all %d", call->state);
716
717         switch (call->state) {
718         case RXRPC_CALL_CLIENT_AWAIT_REPLY:
719                 call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
720                 break;
721         case RXRPC_CALL_SERVER_AWAIT_ACK:
722                 _debug("srv complete");
723                 call->state = RXRPC_CALL_COMPLETE;
724                 post_ACK = true;
725                 break;
726         case RXRPC_CALL_CLIENT_SEND_REQUEST:
727         case RXRPC_CALL_SERVER_RECV_REQUEST:
728                 goto protocol_error_unlock; /* can't occur yet */
729         default:
730                 write_unlock_bh(&call->state_lock);
731                 goto discard; /* assume packet left over from earlier phase */
732         }
733
734         write_unlock_bh(&call->state_lock);
735
736         /* if all the packets we sent are hard-ACK'd, then we can discard
737          * whatever we've got left */
738         _debug("clear Tx %d",
739                CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
740
741         del_timer_sync(&call->resend_timer);
742         clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
743         clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
744
745         if (call->acks_window)
746                 rxrpc_zap_tx_window(call);
747
748         if (post_ACK) {
749                 /* post the final ACK message for userspace to pick up */
750                 _debug("post ACK");
751                 skb->mark = RXRPC_SKB_MARK_FINAL_ACK;
752                 sp->call = call;
753                 rxrpc_get_call(call);
754                 spin_lock_bh(&call->lock);
755                 if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0)
756                         BUG();
757                 spin_unlock_bh(&call->lock);
758                 goto process_further;
759         }
760
761 discard:
762         rxrpc_free_skb(skb);
763         goto process_further;
764
765 protocol_error_unlock:
766         write_unlock_bh(&call->state_lock);
767 protocol_error:
768         rxrpc_free_skb(skb);
769         _leave(" = -EPROTO");
770         return -EPROTO;
771 }
772
773 /*
774  * post a message to the socket Rx queue for recvmsg() to pick up
775  */
776 static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error,
777                               bool fatal)
778 {
779         struct rxrpc_skb_priv *sp;
780         struct sk_buff *skb;
781         int ret;
782
783         _enter("{%d,%lx},%u,%u,%d",
784                call->debug_id, call->flags, mark, error, fatal);
785
786         /* remove timers and things for fatal messages */
787         if (fatal) {
788                 del_timer_sync(&call->resend_timer);
789                 del_timer_sync(&call->ack_timer);
790                 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
791         }
792
793         if (mark != RXRPC_SKB_MARK_NEW_CALL &&
794             !test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
795                 _leave("[no userid]");
796                 return 0;
797         }
798
799         if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
800                 skb = alloc_skb(0, GFP_NOFS);
801                 if (!skb)
802                         return -ENOMEM;
803
804                 rxrpc_new_skb(skb);
805
806                 skb->mark = mark;
807
808                 sp = rxrpc_skb(skb);
809                 memset(sp, 0, sizeof(*sp));
810                 sp->error = error;
811                 sp->call = call;
812                 rxrpc_get_call(call);
813
814                 spin_lock_bh(&call->lock);
815                 ret = rxrpc_queue_rcv_skb(call, skb, true, fatal);
816                 spin_unlock_bh(&call->lock);
817                 BUG_ON(ret < 0);
818         }
819
820         return 0;
821 }
822
823 /*
824  * handle background processing of incoming call packets and ACK / abort
825  * generation
826  */
827 void rxrpc_process_call(struct work_struct *work)
828 {
829         struct rxrpc_call *call =
830                 container_of(work, struct rxrpc_call, processor);
831         struct rxrpc_ackpacket ack;
832         struct rxrpc_ackinfo ackinfo;
833         struct rxrpc_header hdr;
834         struct msghdr msg;
835         struct kvec iov[5];
836         unsigned long bits;
837         __be32 data, pad;
838         size_t len;
839         int genbit, loop, nbit, ioc, ret, mtu;
840         u32 abort_code = RX_PROTOCOL_ERROR;
841         u8 *acks = NULL;
842
843         //printk("\n--------------------\n");
844         _enter("{%d,%s,%lx} [%lu]",
845                call->debug_id, rxrpc_call_states[call->state], call->events,
846                (jiffies - call->creation_jif) / (HZ / 10));
847
848         if (test_and_set_bit(RXRPC_CALL_PROC_BUSY, &call->flags)) {
849                 _debug("XXXXXXXXXXXXX RUNNING ON MULTIPLE CPUS XXXXXXXXXXXXX");
850                 return;
851         }
852
853         /* there's a good chance we're going to have to send a message, so set
854          * one up in advance */
855         msg.msg_name    = &call->conn->trans->peer->srx.transport.sin;
856         msg.msg_namelen = sizeof(call->conn->trans->peer->srx.transport.sin);
857         msg.msg_control = NULL;
858         msg.msg_controllen = 0;
859         msg.msg_flags   = 0;
860
861         hdr.epoch       = call->conn->epoch;
862         hdr.cid         = call->cid;
863         hdr.callNumber  = call->call_id;
864         hdr.seq         = 0;
865         hdr.type        = RXRPC_PACKET_TYPE_ACK;
866         hdr.flags       = call->conn->out_clientflag;
867         hdr.userStatus  = 0;
868         hdr.securityIndex = call->conn->security_ix;
869         hdr._rsvd       = 0;
870         hdr.serviceId   = call->conn->service_id;
871
872         memset(iov, 0, sizeof(iov));
873         iov[0].iov_base = &hdr;
874         iov[0].iov_len  = sizeof(hdr);
875
876         /* deal with events of a final nature */
877         if (test_bit(RXRPC_CALL_RELEASE, &call->events)) {
878                 rxrpc_release_call(call);
879                 clear_bit(RXRPC_CALL_RELEASE, &call->events);
880         }
881
882         if (test_bit(RXRPC_CALL_RCVD_ERROR, &call->events)) {
883                 int error;
884
885                 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
886                 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
887                 clear_bit(RXRPC_CALL_ABORT, &call->events);
888
889                 error = call->conn->trans->peer->net_error;
890                 _debug("post net error %d", error);
891
892                 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NET_ERROR,
893                                        error, true) < 0)
894                         goto no_mem;
895                 clear_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
896                 goto kill_ACKs;
897         }
898
899         if (test_bit(RXRPC_CALL_CONN_ABORT, &call->events)) {
900                 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
901
902                 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
903                 clear_bit(RXRPC_CALL_ABORT, &call->events);
904
905                 _debug("post conn abort");
906
907                 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
908                                        call->conn->error, true) < 0)
909                         goto no_mem;
910                 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
911                 goto kill_ACKs;
912         }
913
914         if (test_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) {
915                 hdr.type = RXRPC_PACKET_TYPE_BUSY;
916                 genbit = RXRPC_CALL_REJECT_BUSY;
917                 goto send_message;
918         }
919
920         if (test_bit(RXRPC_CALL_ABORT, &call->events)) {
921                 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
922
923                 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
924                                        ECONNABORTED, true) < 0)
925                         goto no_mem;
926                 hdr.type = RXRPC_PACKET_TYPE_ABORT;
927                 data = htonl(call->abort_code);
928                 iov[1].iov_base = &data;
929                 iov[1].iov_len = sizeof(data);
930                 genbit = RXRPC_CALL_ABORT;
931                 goto send_message;
932         }
933
934         if (test_bit(RXRPC_CALL_ACK_FINAL, &call->events)) {
935                 genbit = RXRPC_CALL_ACK_FINAL;
936
937                 ack.bufferSpace = htons(8);
938                 ack.maxSkew     = 0;
939                 ack.serial      = 0;
940                 ack.reason      = RXRPC_ACK_IDLE;
941                 ack.nAcks       = 0;
942                 call->ackr_reason = 0;
943
944                 spin_lock_bh(&call->lock);
945                 ack.serial = call->ackr_serial;
946                 ack.previousPacket = call->ackr_prev_seq;
947                 ack.firstPacket = htonl(call->rx_data_eaten + 1);
948                 spin_unlock_bh(&call->lock);
949
950                 pad = 0;
951
952                 iov[1].iov_base = &ack;
953                 iov[1].iov_len  = sizeof(ack);
954                 iov[2].iov_base = &pad;
955                 iov[2].iov_len  = 3;
956                 iov[3].iov_base = &ackinfo;
957                 iov[3].iov_len  = sizeof(ackinfo);
958                 goto send_ACK;
959         }
960
961         if (call->events & ((1 << RXRPC_CALL_RCVD_BUSY) |
962                             (1 << RXRPC_CALL_RCVD_ABORT))
963             ) {
964                 u32 mark;
965
966                 if (test_bit(RXRPC_CALL_RCVD_ABORT, &call->events))
967                         mark = RXRPC_SKB_MARK_REMOTE_ABORT;
968                 else
969                         mark = RXRPC_SKB_MARK_BUSY;
970
971                 _debug("post abort/busy");
972                 rxrpc_clear_tx_window(call);
973                 if (rxrpc_post_message(call, mark, ECONNABORTED, true) < 0)
974                         goto no_mem;
975
976                 clear_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
977                 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
978                 goto kill_ACKs;
979         }
980
981         if (test_and_clear_bit(RXRPC_CALL_RCVD_ACKALL, &call->events)) {
982                 _debug("do implicit ackall");
983                 rxrpc_clear_tx_window(call);
984         }
985
986         if (test_bit(RXRPC_CALL_LIFE_TIMER, &call->events)) {
987                 write_lock_bh(&call->state_lock);
988                 if (call->state <= RXRPC_CALL_COMPLETE) {
989                         call->state = RXRPC_CALL_LOCALLY_ABORTED;
990                         call->abort_code = RX_CALL_TIMEOUT;
991                         set_bit(RXRPC_CALL_ABORT, &call->events);
992                 }
993                 write_unlock_bh(&call->state_lock);
994
995                 _debug("post timeout");
996                 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
997                                        ETIME, true) < 0)
998                         goto no_mem;
999
1000                 clear_bit(RXRPC_CALL_LIFE_TIMER, &call->events);
1001                 goto kill_ACKs;
1002         }
1003
1004         /* deal with assorted inbound messages */
1005         if (!skb_queue_empty(&call->rx_queue)) {
1006                 switch (rxrpc_process_rx_queue(call, &abort_code)) {
1007                 case 0:
1008                 case -EAGAIN:
1009                         break;
1010                 case -ENOMEM:
1011                         goto no_mem;
1012                 case -EKEYEXPIRED:
1013                 case -EKEYREJECTED:
1014                 case -EPROTO:
1015                         rxrpc_abort_call(call, abort_code);
1016                         goto kill_ACKs;
1017                 }
1018         }
1019
1020         /* handle resending */
1021         if (test_and_clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
1022                 rxrpc_resend_timer(call);
1023         if (test_and_clear_bit(RXRPC_CALL_RESEND, &call->events))
1024                 rxrpc_resend(call);
1025
1026         /* consider sending an ordinary ACK */
1027         if (test_bit(RXRPC_CALL_ACK, &call->events)) {
1028                 _debug("send ACK: window: %d - %d { %lx }",
1029                        call->rx_data_eaten, call->ackr_win_top,
1030                        call->ackr_window[0]);
1031
1032                 if (call->state > RXRPC_CALL_SERVER_ACK_REQUEST &&
1033                     call->ackr_reason != RXRPC_ACK_PING_RESPONSE) {
1034                         /* ACK by sending reply DATA packet in this state */
1035                         clear_bit(RXRPC_CALL_ACK, &call->events);
1036                         goto maybe_reschedule;
1037                 }
1038
1039                 genbit = RXRPC_CALL_ACK;
1040
1041                 acks = kzalloc(call->ackr_win_top - call->rx_data_eaten,
1042                                GFP_NOFS);
1043                 if (!acks)
1044                         goto no_mem;
1045
1046                 //hdr.flags     = RXRPC_SLOW_START_OK;
1047                 ack.bufferSpace = htons(8);
1048                 ack.maxSkew     = 0;
1049                 ack.serial      = 0;
1050                 ack.reason      = 0;
1051
1052                 spin_lock_bh(&call->lock);
1053                 ack.reason = call->ackr_reason;
1054                 ack.serial = call->ackr_serial;
1055                 ack.previousPacket = call->ackr_prev_seq;
1056                 ack.firstPacket = htonl(call->rx_data_eaten + 1);
1057
1058                 ack.nAcks = 0;
1059                 for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) {
1060                         nbit = loop * BITS_PER_LONG;
1061                         for (bits = call->ackr_window[loop]; bits; bits >>= 1
1062                              ) {
1063                                 _debug("- l=%d n=%d b=%lx", loop, nbit, bits);
1064                                 if (bits & 1) {
1065                                         acks[nbit] = RXRPC_ACK_TYPE_ACK;
1066                                         ack.nAcks = nbit + 1;
1067                                 }
1068                                 nbit++;
1069                         }
1070                 }
1071                 call->ackr_reason = 0;
1072                 spin_unlock_bh(&call->lock);
1073
1074                 pad = 0;
1075
1076                 iov[1].iov_base = &ack;
1077                 iov[1].iov_len  = sizeof(ack);
1078                 iov[2].iov_base = acks;
1079                 iov[2].iov_len  = ack.nAcks;
1080                 iov[3].iov_base = &pad;
1081                 iov[3].iov_len  = 3;
1082                 iov[4].iov_base = &ackinfo;
1083                 iov[4].iov_len  = sizeof(ackinfo);
1084
1085                 switch (ack.reason) {
1086                 case RXRPC_ACK_REQUESTED:
1087                 case RXRPC_ACK_DUPLICATE:
1088                 case RXRPC_ACK_OUT_OF_SEQUENCE:
1089                 case RXRPC_ACK_EXCEEDS_WINDOW:
1090                 case RXRPC_ACK_NOSPACE:
1091                 case RXRPC_ACK_PING:
1092                 case RXRPC_ACK_PING_RESPONSE:
1093                         goto send_ACK_with_skew;
1094                 case RXRPC_ACK_DELAY:
1095                 case RXRPC_ACK_IDLE:
1096                         goto send_ACK;
1097                 }
1098         }
1099
1100         /* handle completion of security negotiations on an incoming
1101          * connection */
1102         if (test_and_clear_bit(RXRPC_CALL_SECURED, &call->events)) {
1103                 _debug("secured");
1104                 spin_lock_bh(&call->lock);
1105
1106                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
1107                         _debug("securing");
1108                         write_lock(&call->conn->lock);
1109                         if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
1110                             !test_bit(RXRPC_CALL_RELEASE, &call->events)) {
1111                                 _debug("not released");
1112                                 call->state = RXRPC_CALL_SERVER_ACCEPTING;
1113                                 list_move_tail(&call->accept_link,
1114                                                &call->socket->acceptq);
1115                         }
1116                         write_unlock(&call->conn->lock);
1117                         read_lock(&call->state_lock);
1118                         if (call->state < RXRPC_CALL_COMPLETE)
1119                                 set_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
1120                         read_unlock(&call->state_lock);
1121                 }
1122
1123                 spin_unlock_bh(&call->lock);
1124                 if (!test_bit(RXRPC_CALL_POST_ACCEPT, &call->events))
1125                         goto maybe_reschedule;
1126         }
1127
1128         /* post a notification of an acceptable connection to the app */
1129         if (test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) {
1130                 _debug("post accept");
1131                 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NEW_CALL,
1132                                        0, false) < 0)
1133                         goto no_mem;
1134                 clear_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
1135                 goto maybe_reschedule;
1136         }
1137
1138         /* handle incoming call acceptance */
1139         if (test_and_clear_bit(RXRPC_CALL_ACCEPTED, &call->events)) {
1140                 _debug("accepted");
1141                 ASSERTCMP(call->rx_data_post, ==, 0);
1142                 call->rx_data_post = 1;
1143                 read_lock_bh(&call->state_lock);
1144                 if (call->state < RXRPC_CALL_COMPLETE)
1145                         set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
1146                 read_unlock_bh(&call->state_lock);
1147         }
1148
1149         /* drain the out of sequence received packet queue into the packet Rx
1150          * queue */
1151         if (test_and_clear_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events)) {
1152                 while (call->rx_data_post == call->rx_first_oos)
1153                         if (rxrpc_drain_rx_oos_queue(call) < 0)
1154                                 break;
1155                 goto maybe_reschedule;
1156         }
1157
1158         /* other events may have been raised since we started checking */
1159         goto maybe_reschedule;
1160
1161 send_ACK_with_skew:
1162         ack.maxSkew = htons(atomic_read(&call->conn->hi_serial) -
1163                             ntohl(ack.serial));
1164 send_ACK:
1165         mtu = call->conn->trans->peer->if_mtu;
1166         mtu -= call->conn->trans->peer->hdrsize;
1167         ackinfo.maxMTU  = htonl(mtu);
1168         ackinfo.rwind   = htonl(32);
1169
1170         /* permit the peer to send us jumbo packets if it wants to */
1171         ackinfo.rxMTU   = htonl(5692);
1172         ackinfo.jumbo_max = htonl(4);
1173
1174         hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
1175         _proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
1176                ntohl(hdr.serial),
1177                ntohs(ack.maxSkew),
1178                ntohl(ack.firstPacket),
1179                ntohl(ack.previousPacket),
1180                ntohl(ack.serial),
1181                rxrpc_acks[ack.reason],
1182                ack.nAcks);
1183
1184         del_timer_sync(&call->ack_timer);
1185         if (ack.nAcks > 0)
1186                 set_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags);
1187         goto send_message_2;
1188
1189 send_message:
1190         _debug("send message");
1191
1192         hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
1193         _proto("Tx %s %%%u", rxrpc_pkts[hdr.type], ntohl(hdr.serial));
1194 send_message_2:
1195
1196         len = iov[0].iov_len;
1197         ioc = 1;
1198         if (iov[4].iov_len) {
1199                 ioc = 5;
1200                 len += iov[4].iov_len;
1201                 len += iov[3].iov_len;
1202                 len += iov[2].iov_len;
1203                 len += iov[1].iov_len;
1204         } else if (iov[3].iov_len) {
1205                 ioc = 4;
1206                 len += iov[3].iov_len;
1207                 len += iov[2].iov_len;
1208                 len += iov[1].iov_len;
1209         } else if (iov[2].iov_len) {
1210                 ioc = 3;
1211                 len += iov[2].iov_len;
1212                 len += iov[1].iov_len;
1213         } else if (iov[1].iov_len) {
1214                 ioc = 2;
1215                 len += iov[1].iov_len;
1216         }
1217
1218         ret = kernel_sendmsg(call->conn->trans->local->socket,
1219                              &msg, iov, ioc, len);
1220         if (ret < 0) {
1221                 _debug("sendmsg failed: %d", ret);
1222                 read_lock_bh(&call->state_lock);
1223                 if (call->state < RXRPC_CALL_DEAD)
1224                         rxrpc_queue_call(call);
1225                 read_unlock_bh(&call->state_lock);
1226                 goto error;
1227         }
1228
1229         switch (genbit) {
1230         case RXRPC_CALL_ABORT:
1231                 clear_bit(genbit, &call->events);
1232                 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
1233                 goto kill_ACKs;
1234
1235         case RXRPC_CALL_ACK_FINAL:
1236                 write_lock_bh(&call->state_lock);
1237                 if (call->state == RXRPC_CALL_CLIENT_FINAL_ACK)
1238                         call->state = RXRPC_CALL_COMPLETE;
1239                 write_unlock_bh(&call->state_lock);
1240                 goto kill_ACKs;
1241
1242         default:
1243                 clear_bit(genbit, &call->events);
1244                 switch (call->state) {
1245                 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
1246                 case RXRPC_CALL_CLIENT_RECV_REPLY:
1247                 case RXRPC_CALL_SERVER_RECV_REQUEST:
1248                 case RXRPC_CALL_SERVER_ACK_REQUEST:
1249                         _debug("start ACK timer");
1250                         rxrpc_propose_ACK(call, RXRPC_ACK_DELAY,
1251                                           call->ackr_serial, false);
1252                 default:
1253                         break;
1254                 }
1255                 goto maybe_reschedule;
1256         }
1257
1258 kill_ACKs:
1259         del_timer_sync(&call->ack_timer);
1260         if (test_and_clear_bit(RXRPC_CALL_ACK_FINAL, &call->events))
1261                 rxrpc_put_call(call);
1262         clear_bit(RXRPC_CALL_ACK, &call->events);
1263
1264 maybe_reschedule:
1265         if (call->events || !skb_queue_empty(&call->rx_queue)) {
1266                 read_lock_bh(&call->state_lock);
1267                 if (call->state < RXRPC_CALL_DEAD)
1268                         rxrpc_queue_call(call);
1269                 read_unlock_bh(&call->state_lock);
1270         }
1271
1272         /* don't leave aborted connections on the accept queue */
1273         if (call->state >= RXRPC_CALL_COMPLETE &&
1274             !list_empty(&call->accept_link)) {
1275                 _debug("X unlinking once-pending call %p { e=%lx f=%lx c=%x }",
1276                        call, call->events, call->flags,
1277                        ntohl(call->conn->cid));
1278
1279                 read_lock_bh(&call->state_lock);
1280                 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
1281                     !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
1282                         rxrpc_queue_call(call);
1283                 read_unlock_bh(&call->state_lock);
1284         }
1285
1286 error:
1287         clear_bit(RXRPC_CALL_PROC_BUSY, &call->flags);
1288         kfree(acks);
1289
1290         /* because we don't want two CPUs both processing the work item for one
1291          * call at the same time, we use a flag to note when it's busy; however
1292          * this means there's a race between clearing the flag and setting the
1293          * work pending bit and the work item being processed again */
1294         if (call->events && !work_pending(&call->processor)) {
1295                 _debug("jumpstart %x", ntohl(call->conn->cid));
1296                 rxrpc_queue_call(call);
1297         }
1298
1299         _leave("");
1300         return;
1301
1302 no_mem:
1303         _debug("out of memory");
1304         goto maybe_reschedule;
1305 }