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Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux
[linux/fpc-iii.git] / net / rxrpc / ar-ack.c
blobc6be17a959a6e4981ecfff38af85805df6d8b26e
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/slab.h>
17 #include <linux/udp.h>
18 #include <net/sock.h>
19 #include <net/af_rxrpc.h>
20 #include "ar-internal.h"
21
22 /*
23 * How long to wait before scheduling ACK generation after seeing a
24 * packet with RXRPC_REQUEST_ACK set (in jiffies).
25 */
26 unsigned rxrpc_requested_ack_delay = 1;
27
28 /*
29 * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
30 *
31 * We use this when we've received new data packets. If those packets aren't
32 * all consumed within this time we will send a DELAY ACK if an ACK was not
33 * requested to let the sender know it doesn't need to resend.
34 */
35 unsigned rxrpc_soft_ack_delay = 1 * HZ;
36
37 /*
38 * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
39 *
40 * We use this when we've consumed some previously soft-ACK'd packets when
41 * further packets aren't immediately received to decide when to send an IDLE
42 * ACK let the other end know that it can free up its Tx buffer space.
43 */
44 unsigned rxrpc_idle_ack_delay = 0.5 * HZ;
45
46 /*
47 * Receive window size in packets. This indicates the maximum number of
48 * unconsumed received packets we're willing to retain in memory. Once this
49 * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
50 * packets.
51 */
52 unsigned rxrpc_rx_window_size = 32;
53
54 /*
55 * Maximum Rx MTU size. This indicates to the sender the size of jumbo packet
56 * made by gluing normal packets together that we're willing to handle.
57 */
58 unsigned rxrpc_rx_mtu = 5692;
59
60 /*
61 * The maximum number of fragments in a received jumbo packet that we tell the
62 * sender that we're willing to handle.
63 */
64 unsigned rxrpc_rx_jumbo_max = 4;
65
66 static const char *rxrpc_acks(u8 reason)
67 {
68 static const char *const str[] = {
69 "---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
70 "IDL", "-?-"
71 };
72
73 if (reason >= ARRAY_SIZE(str))
74 reason = ARRAY_SIZE(str) - 1;
75 return str[reason];
76 }
77
78 static const s8 rxrpc_ack_priority[] = {
79 [0] = 0,
80 [RXRPC_ACK_DELAY] = 1,
81 [RXRPC_ACK_REQUESTED] = 2,
82 [RXRPC_ACK_IDLE] = 3,
83 [RXRPC_ACK_PING_RESPONSE] = 4,
84 [RXRPC_ACK_DUPLICATE] = 5,
85 [RXRPC_ACK_OUT_OF_SEQUENCE] = 6,
86 [RXRPC_ACK_EXCEEDS_WINDOW] = 7,
87 [RXRPC_ACK_NOSPACE] = 8,
88 };
89
90 /*
91 * propose an ACK be sent
92 */
93 void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
94 __be32 serial, bool immediate)
95 {
96 unsigned long expiry;
97 s8 prior = rxrpc_ack_priority[ack_reason];
98
99 ASSERTCMP(prior, >, 0);
100
101 _enter("{%d},%s,%%%x,%u",
102 call->debug_id, rxrpc_acks(ack_reason), ntohl(serial),
103 immediate);
104
105 if (prior < rxrpc_ack_priority[call->ackr_reason]) {
106 if (immediate)
107 goto cancel_timer;
108 return;
109 }
110
111 /* update DELAY, IDLE, REQUESTED and PING_RESPONSE ACK serial
112 * numbers */
113 if (prior == rxrpc_ack_priority[call->ackr_reason]) {
114 if (prior <= 4)
115 call->ackr_serial = serial;
116 if (immediate)
117 goto cancel_timer;
118 return;
119 }
120
121 call->ackr_reason = ack_reason;
122 call->ackr_serial = serial;
123
124 switch (ack_reason) {
125 case RXRPC_ACK_DELAY:
126 _debug("run delay timer");
127 expiry = rxrpc_soft_ack_delay;
128 goto run_timer;
129
130 case RXRPC_ACK_IDLE:
131 if (!immediate) {
132 _debug("run defer timer");
133 expiry = rxrpc_idle_ack_delay;
134 goto run_timer;
135 }
136 goto cancel_timer;
137
138 case RXRPC_ACK_REQUESTED:
139 expiry = rxrpc_requested_ack_delay;
140 if (!expiry)
141 goto cancel_timer;
142 if (!immediate || serial == cpu_to_be32(1)) {
143 _debug("run defer timer");
144 goto run_timer;
145 }
146
147 default:
148 _debug("immediate ACK");
149 goto cancel_timer;
150 }
151
152 run_timer:
153 expiry += jiffies;
154 if (!timer_pending(&call->ack_timer) ||
155 time_after(call->ack_timer.expires, expiry))
156 mod_timer(&call->ack_timer, expiry);
157 return;
158
159 cancel_timer:
160 _debug("cancel timer %%%u", ntohl(serial));
161 try_to_del_timer_sync(&call->ack_timer);
162 read_lock_bh(&call->state_lock);
163 if (call->state <= RXRPC_CALL_COMPLETE &&
164 !test_and_set_bit(RXRPC_CALL_ACK, &call->events))
165 rxrpc_queue_call(call);
166 read_unlock_bh(&call->state_lock);
167 }
168
169 /*
170 * propose an ACK be sent, locking the call structure
171 */
172 void rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
173 __be32 serial, bool immediate)
174 {
175 s8 prior = rxrpc_ack_priority[ack_reason];
176
177 if (prior > rxrpc_ack_priority[call->ackr_reason]) {
178 spin_lock_bh(&call->lock);
179 __rxrpc_propose_ACK(call, ack_reason, serial, immediate);
180 spin_unlock_bh(&call->lock);
181 }
182 }
183
184 /*
185 * set the resend timer
186 */
187 static void rxrpc_set_resend(struct rxrpc_call *call, u8 resend,
188 unsigned long resend_at)
189 {
190 read_lock_bh(&call->state_lock);
191 if (call->state >= RXRPC_CALL_COMPLETE)
192 resend = 0;
193
194 if (resend & 1) {
195 _debug("SET RESEND");
196 set_bit(RXRPC_CALL_RESEND, &call->events);
197 }
198
199 if (resend & 2) {
200 _debug("MODIFY RESEND TIMER");
201 set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
202 mod_timer(&call->resend_timer, resend_at);
203 } else {
204 _debug("KILL RESEND TIMER");
205 del_timer_sync(&call->resend_timer);
206 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
207 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
208 }
209 read_unlock_bh(&call->state_lock);
210 }
211
212 /*
213 * resend packets
214 */
215 static void rxrpc_resend(struct rxrpc_call *call)
216 {
217 struct rxrpc_skb_priv *sp;
218 struct rxrpc_header *hdr;
219 struct sk_buff *txb;
220 unsigned long *p_txb, resend_at;
221 int loop, stop;
222 u8 resend;
223
224 _enter("{%d,%d,%d,%d},",
225 call->acks_hard, call->acks_unacked,
226 atomic_read(&call->sequence),
227 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
228
229 stop = 0;
230 resend = 0;
231 resend_at = 0;
232
233 for (loop = call->acks_tail;
234 loop != call->acks_head || stop;
235 loop = (loop + 1) & (call->acks_winsz - 1)
236 ) {
237 p_txb = call->acks_window + loop;
238 smp_read_barrier_depends();
239 if (*p_txb & 1)
240 continue;
241
242 txb = (struct sk_buff *) *p_txb;
243 sp = rxrpc_skb(txb);
244
245 if (sp->need_resend) {
246 sp->need_resend = false;
247
248 /* each Tx packet has a new serial number */
249 sp->hdr.serial =
250 htonl(atomic_inc_return(&call->conn->serial));
251
252 hdr = (struct rxrpc_header *) txb->head;
253 hdr->serial = sp->hdr.serial;
254
255 _proto("Tx DATA %%%u { #%d }",
256 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
257 if (rxrpc_send_packet(call->conn->trans, txb) < 0) {
258 stop = 0;
259 sp->resend_at = jiffies + 3;
260 } else {
261 sp->resend_at =
262 jiffies + rxrpc_resend_timeout * HZ;
263 }
264 }
265
266 if (time_after_eq(jiffies + 1, sp->resend_at)) {
267 sp->need_resend = true;
268 resend |= 1;
269 } else if (resend & 2) {
270 if (time_before(sp->resend_at, resend_at))
271 resend_at = sp->resend_at;
272 } else {
273 resend_at = sp->resend_at;
274 resend |= 2;
275 }
276 }
277
278 rxrpc_set_resend(call, resend, resend_at);
279 _leave("");
280 }
281
282 /*
283 * handle resend timer expiry
284 */
285 static void rxrpc_resend_timer(struct rxrpc_call *call)
286 {
287 struct rxrpc_skb_priv *sp;
288 struct sk_buff *txb;
289 unsigned long *p_txb, resend_at;
290 int loop;
291 u8 resend;
292
293 _enter("%d,%d,%d",
294 call->acks_tail, call->acks_unacked, call->acks_head);
295
296 if (call->state >= RXRPC_CALL_COMPLETE)
297 return;
298
299 resend = 0;
300 resend_at = 0;
301
302 for (loop = call->acks_unacked;
303 loop != call->acks_head;
304 loop = (loop + 1) & (call->acks_winsz - 1)
305 ) {
306 p_txb = call->acks_window + loop;
307 smp_read_barrier_depends();
308 txb = (struct sk_buff *) (*p_txb & ~1);
309 sp = rxrpc_skb(txb);
310
311 ASSERT(!(*p_txb & 1));
312
313 if (sp->need_resend) {
314 ;
315 } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
316 sp->need_resend = true;
317 resend |= 1;
318 } else if (resend & 2) {
319 if (time_before(sp->resend_at, resend_at))
320 resend_at = sp->resend_at;
321 } else {
322 resend_at = sp->resend_at;
323 resend |= 2;
324 }
325 }
326
327 rxrpc_set_resend(call, resend, resend_at);
328 _leave("");
329 }
330
331 /*
332 * process soft ACKs of our transmitted packets
333 * - these indicate packets the peer has or has not received, but hasn't yet
334 * given to the consumer, and so can still be discarded and re-requested
335 */
336 static int rxrpc_process_soft_ACKs(struct rxrpc_call *call,
337 struct rxrpc_ackpacket *ack,
338 struct sk_buff *skb)
339 {
340 struct rxrpc_skb_priv *sp;
341 struct sk_buff *txb;
342 unsigned long *p_txb, resend_at;
343 int loop;
344 u8 sacks[RXRPC_MAXACKS], resend;
345
346 _enter("{%d,%d},{%d},",
347 call->acks_hard,
348 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz),
349 ack->nAcks);
350
351 if (skb_copy_bits(skb, 0, sacks, ack->nAcks) < 0)
352 goto protocol_error;
353
354 resend = 0;
355 resend_at = 0;
356 for (loop = 0; loop < ack->nAcks; loop++) {
357 p_txb = call->acks_window;
358 p_txb += (call->acks_tail + loop) & (call->acks_winsz - 1);
359 smp_read_barrier_depends();
360 txb = (struct sk_buff *) (*p_txb & ~1);
361 sp = rxrpc_skb(txb);
362
363 switch (sacks[loop]) {
364 case RXRPC_ACK_TYPE_ACK:
365 sp->need_resend = false;
366 *p_txb |= 1;
367 break;
368 case RXRPC_ACK_TYPE_NACK:
369 sp->need_resend = true;
370 *p_txb &= ~1;
371 resend = 1;
372 break;
373 default:
374 _debug("Unsupported ACK type %d", sacks[loop]);
375 goto protocol_error;
376 }
377 }
378
379 smp_mb();
380 call->acks_unacked = (call->acks_tail + loop) & (call->acks_winsz - 1);
381
382 /* anything not explicitly ACK'd is implicitly NACK'd, but may just not
383 * have been received or processed yet by the far end */
384 for (loop = call->acks_unacked;
385 loop != call->acks_head;
386 loop = (loop + 1) & (call->acks_winsz - 1)
387 ) {
388 p_txb = call->acks_window + loop;
389 smp_read_barrier_depends();
390 txb = (struct sk_buff *) (*p_txb & ~1);
391 sp = rxrpc_skb(txb);
392
393 if (*p_txb & 1) {
394 /* packet must have been discarded */
395 sp->need_resend = true;
396 *p_txb &= ~1;
397 resend |= 1;
398 } else if (sp->need_resend) {
399 ;
400 } else if (time_after_eq(jiffies + 1, sp->resend_at)) {
401 sp->need_resend = true;
402 resend |= 1;
403 } else if (resend & 2) {
404 if (time_before(sp->resend_at, resend_at))
405 resend_at = sp->resend_at;
406 } else {
407 resend_at = sp->resend_at;
408 resend |= 2;
409 }
410 }
411
412 rxrpc_set_resend(call, resend, resend_at);
413 _leave(" = 0");
414 return 0;
415
416 protocol_error:
417 _leave(" = -EPROTO");
418 return -EPROTO;
419 }
420
421 /*
422 * discard hard-ACK'd packets from the Tx window
423 */
424 static void rxrpc_rotate_tx_window(struct rxrpc_call *call, u32 hard)
425 {
426 unsigned long _skb;
427 int tail = call->acks_tail, old_tail;
428 int win = CIRC_CNT(call->acks_head, tail, call->acks_winsz);
429
430 _enter("{%u,%u},%u", call->acks_hard, win, hard);
431
432 ASSERTCMP(hard - call->acks_hard, <=, win);
433
434 while (call->acks_hard < hard) {
435 smp_read_barrier_depends();
436 _skb = call->acks_window[tail] & ~1;
437 rxrpc_free_skb((struct sk_buff *) _skb);
438 old_tail = tail;
439 tail = (tail + 1) & (call->acks_winsz - 1);
440 call->acks_tail = tail;
441 if (call->acks_unacked == old_tail)
442 call->acks_unacked = tail;
443 call->acks_hard++;
444 }
445
446 wake_up(&call->tx_waitq);
447 }
448
449 /*
450 * clear the Tx window in the event of a failure
451 */
452 static void rxrpc_clear_tx_window(struct rxrpc_call *call)
453 {
454 rxrpc_rotate_tx_window(call, atomic_read(&call->sequence));
455 }
456
457 /*
458 * drain the out of sequence received packet queue into the packet Rx queue
459 */
460 static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call)
461 {
462 struct rxrpc_skb_priv *sp;
463 struct sk_buff *skb;
464 bool terminal;
465 int ret;
466
467 _enter("{%d,%d}", call->rx_data_post, call->rx_first_oos);
468
469 spin_lock_bh(&call->lock);
470
471 ret = -ECONNRESET;
472 if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
473 goto socket_unavailable;
474
475 skb = skb_dequeue(&call->rx_oos_queue);
476 if (skb) {
477 sp = rxrpc_skb(skb);
478
479 _debug("drain OOS packet %d [%d]",
480 ntohl(sp->hdr.seq), call->rx_first_oos);
481
482 if (ntohl(sp->hdr.seq) != call->rx_first_oos) {
483 skb_queue_head(&call->rx_oos_queue, skb);
484 call->rx_first_oos = ntohl(rxrpc_skb(skb)->hdr.seq);
485 _debug("requeue %p {%u}", skb, call->rx_first_oos);
486 } else {
487 skb->mark = RXRPC_SKB_MARK_DATA;
488 terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
489 !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
490 ret = rxrpc_queue_rcv_skb(call, skb, true, terminal);
491 BUG_ON(ret < 0);
492 _debug("drain #%u", call->rx_data_post);
493 call->rx_data_post++;
494
495 /* find out what the next packet is */
496 skb = skb_peek(&call->rx_oos_queue);
497 if (skb)
498 call->rx_first_oos =
499 ntohl(rxrpc_skb(skb)->hdr.seq);
500 else
501 call->rx_first_oos = 0;
502 _debug("peek %p {%u}", skb, call->rx_first_oos);
503 }
504 }
505
506 ret = 0;
507 socket_unavailable:
508 spin_unlock_bh(&call->lock);
509 _leave(" = %d", ret);
510 return ret;
511 }
512
513 /*
514 * insert an out of sequence packet into the buffer
515 */
516 static void rxrpc_insert_oos_packet(struct rxrpc_call *call,
517 struct sk_buff *skb)
518 {
519 struct rxrpc_skb_priv *sp, *psp;
520 struct sk_buff *p;
521 u32 seq;
522
523 sp = rxrpc_skb(skb);
524 seq = ntohl(sp->hdr.seq);
525 _enter(",,{%u}", seq);
526
527 skb->destructor = rxrpc_packet_destructor;
528 ASSERTCMP(sp->call, ==, NULL);
529 sp->call = call;
530 rxrpc_get_call(call);
531
532 /* insert into the buffer in sequence order */
533 spin_lock_bh(&call->lock);
534
535 skb_queue_walk(&call->rx_oos_queue, p) {
536 psp = rxrpc_skb(p);
537 if (ntohl(psp->hdr.seq) > seq) {
538 _debug("insert oos #%u before #%u",
539 seq, ntohl(psp->hdr.seq));
540 skb_insert(p, skb, &call->rx_oos_queue);
541 goto inserted;
542 }
543 }
544
545 _debug("append oos #%u", seq);
546 skb_queue_tail(&call->rx_oos_queue, skb);
547 inserted:
548
549 /* we might now have a new front to the queue */
550 if (call->rx_first_oos == 0 || seq < call->rx_first_oos)
551 call->rx_first_oos = seq;
552
553 read_lock(&call->state_lock);
554 if (call->state < RXRPC_CALL_COMPLETE &&
555 call->rx_data_post == call->rx_first_oos) {
556 _debug("drain rx oos now");
557 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
558 }
559 read_unlock(&call->state_lock);
560
561 spin_unlock_bh(&call->lock);
562 _leave(" [stored #%u]", call->rx_first_oos);
563 }
564
565 /*
566 * clear the Tx window on final ACK reception
567 */
568 static void rxrpc_zap_tx_window(struct rxrpc_call *call)
569 {
570 struct rxrpc_skb_priv *sp;
571 struct sk_buff *skb;
572 unsigned long _skb, *acks_window;
573 u8 winsz = call->acks_winsz;
574 int tail;
575
576 acks_window = call->acks_window;
577 call->acks_window = NULL;
578
579 while (CIRC_CNT(call->acks_head, call->acks_tail, winsz) > 0) {
580 tail = call->acks_tail;
581 smp_read_barrier_depends();
582 _skb = acks_window[tail] & ~1;
583 smp_mb();
584 call->acks_tail = (call->acks_tail + 1) & (winsz - 1);
585
586 skb = (struct sk_buff *) _skb;
587 sp = rxrpc_skb(skb);
588 _debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
589 rxrpc_free_skb(skb);
590 }
591
592 kfree(acks_window);
593 }
594
595 /*
596 * process the extra information that may be appended to an ACK packet
597 */
598 static void rxrpc_extract_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
599 unsigned int latest, int nAcks)
600 {
601 struct rxrpc_ackinfo ackinfo;
602 struct rxrpc_peer *peer;
603 unsigned int mtu;
604
605 if (skb_copy_bits(skb, nAcks + 3, &ackinfo, sizeof(ackinfo)) < 0) {
606 _leave(" [no ackinfo]");
607 return;
608 }
609
610 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
611 latest,
612 ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU),
613 ntohl(ackinfo.rwind), ntohl(ackinfo.jumbo_max));
614
615 mtu = min(ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU));
616
617 peer = call->conn->trans->peer;
618 if (mtu < peer->maxdata) {
619 spin_lock_bh(&peer->lock);
620 peer->maxdata = mtu;
621 peer->mtu = mtu + peer->hdrsize;
622 spin_unlock_bh(&peer->lock);
623 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
624 }
625 }
626
627 /*
628 * process packets in the reception queue
629 */
630 static int rxrpc_process_rx_queue(struct rxrpc_call *call,
631 u32 *_abort_code)
632 {
633 struct rxrpc_ackpacket ack;
634 struct rxrpc_skb_priv *sp;
635 struct sk_buff *skb;
636 bool post_ACK;
637 int latest;
638 u32 hard, tx;
639
640 _enter("");
641
642 process_further:
643 skb = skb_dequeue(&call->rx_queue);
644 if (!skb)
645 return -EAGAIN;
646
647 _net("deferred skb %p", skb);
648
649 sp = rxrpc_skb(skb);
650
651 _debug("process %s [st %d]", rxrpc_pkts[sp->hdr.type], call->state);
652
653 post_ACK = false;
654
655 switch (sp->hdr.type) {
656 /* data packets that wind up here have been received out of
657 * order, need security processing or are jumbo packets */
658 case RXRPC_PACKET_TYPE_DATA:
659 _proto("OOSQ DATA %%%u { #%u }",
660 ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
661
662 /* secured packets must be verified and possibly decrypted */
663 if (rxrpc_verify_packet(call, skb, _abort_code) < 0)
664 goto protocol_error;
665
666 rxrpc_insert_oos_packet(call, skb);
667 goto process_further;
668
669 /* partial ACK to process */
670 case RXRPC_PACKET_TYPE_ACK:
671 if (skb_copy_bits(skb, 0, &ack, sizeof(ack)) < 0) {
672 _debug("extraction failure");
673 goto protocol_error;
674 }
675 if (!skb_pull(skb, sizeof(ack)))
676 BUG();
677
678 latest = ntohl(sp->hdr.serial);
679 hard = ntohl(ack.firstPacket);
680 tx = atomic_read(&call->sequence);
681
682 _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
683 latest,
684 ntohs(ack.maxSkew),
685 hard,
686 ntohl(ack.previousPacket),
687 ntohl(ack.serial),
688 rxrpc_acks(ack.reason),
689 ack.nAcks);
690
691 rxrpc_extract_ackinfo(call, skb, latest, ack.nAcks);
692
693 if (ack.reason == RXRPC_ACK_PING) {
694 _proto("Rx ACK %%%u PING Request", latest);
695 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
696 sp->hdr.serial, true);
697 }
698
699 /* discard any out-of-order or duplicate ACKs */
700 if (latest - call->acks_latest <= 0) {
701 _debug("discard ACK %d <= %d",
702 latest, call->acks_latest);
703 goto discard;
704 }
705 call->acks_latest = latest;
706
707 if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
708 call->state != RXRPC_CALL_CLIENT_AWAIT_REPLY &&
709 call->state != RXRPC_CALL_SERVER_SEND_REPLY &&
710 call->state != RXRPC_CALL_SERVER_AWAIT_ACK)
711 goto discard;
712
713 _debug("Tx=%d H=%u S=%d", tx, call->acks_hard, call->state);
714
715 if (hard > 0) {
716 if (hard - 1 > tx) {
717 _debug("hard-ACK'd packet %d not transmitted"
718 " (%d top)",
719 hard - 1, tx);
720 goto protocol_error;
721 }
722
723 if ((call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY ||
724 call->state == RXRPC_CALL_SERVER_AWAIT_ACK) &&
725 hard > tx)
726 goto all_acked;
727
728 smp_rmb();
729 rxrpc_rotate_tx_window(call, hard - 1);
730 }
731
732 if (ack.nAcks > 0) {
733 if (hard - 1 + ack.nAcks > tx) {
734 _debug("soft-ACK'd packet %d+%d not"
735 " transmitted (%d top)",
736 hard - 1, ack.nAcks, tx);
737 goto protocol_error;
738 }
739
740 if (rxrpc_process_soft_ACKs(call, &ack, skb) < 0)
741 goto protocol_error;
742 }
743 goto discard;
744
745 /* complete ACK to process */
746 case RXRPC_PACKET_TYPE_ACKALL:
747 goto all_acked;
748
749 /* abort and busy are handled elsewhere */
750 case RXRPC_PACKET_TYPE_BUSY:
751 case RXRPC_PACKET_TYPE_ABORT:
752 BUG();
753
754 /* connection level events - also handled elsewhere */
755 case RXRPC_PACKET_TYPE_CHALLENGE:
756 case RXRPC_PACKET_TYPE_RESPONSE:
757 case RXRPC_PACKET_TYPE_DEBUG:
758 BUG();
759 }
760
761 /* if we've had a hard ACK that covers all the packets we've sent, then
762 * that ends that phase of the operation */
763 all_acked:
764 write_lock_bh(&call->state_lock);
765 _debug("ack all %d", call->state);
766
767 switch (call->state) {
768 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
769 call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
770 break;
771 case RXRPC_CALL_SERVER_AWAIT_ACK:
772 _debug("srv complete");
773 call->state = RXRPC_CALL_COMPLETE;
774 post_ACK = true;
775 break;
776 case RXRPC_CALL_CLIENT_SEND_REQUEST:
777 case RXRPC_CALL_SERVER_RECV_REQUEST:
778 goto protocol_error_unlock; /* can't occur yet */
779 default:
780 write_unlock_bh(&call->state_lock);
781 goto discard; /* assume packet left over from earlier phase */
782 }
783
784 write_unlock_bh(&call->state_lock);
785
786 /* if all the packets we sent are hard-ACK'd, then we can discard
787 * whatever we've got left */
788 _debug("clear Tx %d",
789 CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
790
791 del_timer_sync(&call->resend_timer);
792 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
793 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
794
795 if (call->acks_window)
796 rxrpc_zap_tx_window(call);
797
798 if (post_ACK) {
799 /* post the final ACK message for userspace to pick up */
800 _debug("post ACK");
801 skb->mark = RXRPC_SKB_MARK_FINAL_ACK;
802 sp->call = call;
803 rxrpc_get_call(call);
804 spin_lock_bh(&call->lock);
805 if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0)
806 BUG();
807 spin_unlock_bh(&call->lock);
808 goto process_further;
809 }
810
811 discard:
812 rxrpc_free_skb(skb);
813 goto process_further;
814
815 protocol_error_unlock:
816 write_unlock_bh(&call->state_lock);
817 protocol_error:
818 rxrpc_free_skb(skb);
819 _leave(" = -EPROTO");
820 return -EPROTO;
821 }
822
823 /*
824 * post a message to the socket Rx queue for recvmsg() to pick up
825 */
826 static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error,
827 bool fatal)
828 {
829 struct rxrpc_skb_priv *sp;
830 struct sk_buff *skb;
831 int ret;
832
833 _enter("{%d,%lx},%u,%u,%d",
834 call->debug_id, call->flags, mark, error, fatal);
835
836 /* remove timers and things for fatal messages */
837 if (fatal) {
838 del_timer_sync(&call->resend_timer);
839 del_timer_sync(&call->ack_timer);
840 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
841 }
842
843 if (mark != RXRPC_SKB_MARK_NEW_CALL &&
844 !test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
845 _leave("[no userid]");
846 return 0;
847 }
848
849 if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
850 skb = alloc_skb(0, GFP_NOFS);
851 if (!skb)
852 return -ENOMEM;
853
854 rxrpc_new_skb(skb);
855
856 skb->mark = mark;
857
858 sp = rxrpc_skb(skb);
859 memset(sp, 0, sizeof(*sp));
860 sp->error = error;
861 sp->call = call;
862 rxrpc_get_call(call);
863
864 spin_lock_bh(&call->lock);
865 ret = rxrpc_queue_rcv_skb(call, skb, true, fatal);
866 spin_unlock_bh(&call->lock);
867 BUG_ON(ret < 0);
868 }
869
870 return 0;
871 }
872
873 /*
874 * handle background processing of incoming call packets and ACK / abort
875 * generation
876 */
877 void rxrpc_process_call(struct work_struct *work)
878 {
879 struct rxrpc_call *call =
880 container_of(work, struct rxrpc_call, processor);
881 struct rxrpc_ackpacket ack;
882 struct rxrpc_ackinfo ackinfo;
883 struct rxrpc_header hdr;
884 struct msghdr msg;
885 struct kvec iov[5];
886 unsigned long bits;
887 __be32 data, pad;
888 size_t len;
889 int genbit, loop, nbit, ioc, ret, mtu;
890 u32 abort_code = RX_PROTOCOL_ERROR;
891 u8 *acks = NULL;
892
893 //printk("\n--------------------\n");
894 _enter("{%d,%s,%lx} [%lu]",
895 call->debug_id, rxrpc_call_states[call->state], call->events,
896 (jiffies - call->creation_jif) / (HZ / 10));
897
898 if (test_and_set_bit(RXRPC_CALL_PROC_BUSY, &call->flags)) {
899 _debug("XXXXXXXXXXXXX RUNNING ON MULTIPLE CPUS XXXXXXXXXXXXX");
900 return;
901 }
902
903 /* there's a good chance we're going to have to send a message, so set
904 * one up in advance */
905 msg.msg_name = &call->conn->trans->peer->srx.transport.sin;
906 msg.msg_namelen = sizeof(call->conn->trans->peer->srx.transport.sin);
907 msg.msg_control = NULL;
908 msg.msg_controllen = 0;
909 msg.msg_flags = 0;
910
911 hdr.epoch = call->conn->epoch;
912 hdr.cid = call->cid;
913 hdr.callNumber = call->call_id;
914 hdr.seq = 0;
915 hdr.type = RXRPC_PACKET_TYPE_ACK;
916 hdr.flags = call->conn->out_clientflag;
917 hdr.userStatus = 0;
918 hdr.securityIndex = call->conn->security_ix;
919 hdr._rsvd = 0;
920 hdr.serviceId = call->conn->service_id;
921
922 memset(iov, 0, sizeof(iov));
923 iov[0].iov_base = &hdr;
924 iov[0].iov_len = sizeof(hdr);
925
926 /* deal with events of a final nature */
927 if (test_bit(RXRPC_CALL_RELEASE, &call->events)) {
928 rxrpc_release_call(call);
929 clear_bit(RXRPC_CALL_RELEASE, &call->events);
930 }
931
932 if (test_bit(RXRPC_CALL_RCVD_ERROR, &call->events)) {
933 int error;
934
935 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
936 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
937 clear_bit(RXRPC_CALL_ABORT, &call->events);
938
939 error = call->conn->trans->peer->net_error;
940 _debug("post net error %d", error);
941
942 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NET_ERROR,
943 error, true) < 0)
944 goto no_mem;
945 clear_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
946 goto kill_ACKs;
947 }
948
949 if (test_bit(RXRPC_CALL_CONN_ABORT, &call->events)) {
950 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
951
952 clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
953 clear_bit(RXRPC_CALL_ABORT, &call->events);
954
955 _debug("post conn abort");
956
957 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
958 call->conn->error, true) < 0)
959 goto no_mem;
960 clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
961 goto kill_ACKs;
962 }
963
964 if (test_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) {
965 hdr.type = RXRPC_PACKET_TYPE_BUSY;
966 genbit = RXRPC_CALL_REJECT_BUSY;
967 goto send_message;
968 }
969
970 if (test_bit(RXRPC_CALL_ABORT, &call->events)) {
971 ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
972
973 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
974 ECONNABORTED, true) < 0)
975 goto no_mem;
976 hdr.type = RXRPC_PACKET_TYPE_ABORT;
977 data = htonl(call->abort_code);
978 iov[1].iov_base = &data;
979 iov[1].iov_len = sizeof(data);
980 genbit = RXRPC_CALL_ABORT;
981 goto send_message;
982 }
983
984 if (test_bit(RXRPC_CALL_ACK_FINAL, &call->events)) {
985 genbit = RXRPC_CALL_ACK_FINAL;
986
987 ack.bufferSpace = htons(8);
988 ack.maxSkew = 0;
989 ack.serial = 0;
990 ack.reason = RXRPC_ACK_IDLE;
991 ack.nAcks = 0;
992 call->ackr_reason = 0;
993
994 spin_lock_bh(&call->lock);
995 ack.serial = call->ackr_serial;
996 ack.previousPacket = call->ackr_prev_seq;
997 ack.firstPacket = htonl(call->rx_data_eaten + 1);
998 spin_unlock_bh(&call->lock);
999
1000 pad = 0;
1001
1002 iov[1].iov_base = &ack;
1003 iov[1].iov_len = sizeof(ack);
1004 iov[2].iov_base = &pad;
1005 iov[2].iov_len = 3;
1006 iov[3].iov_base = &ackinfo;
1007 iov[3].iov_len = sizeof(ackinfo);
1008 goto send_ACK;
1009 }
1010
1011 if (call->events & ((1 << RXRPC_CALL_RCVD_BUSY) |
1012 (1 << RXRPC_CALL_RCVD_ABORT))
1013 ) {
1014 u32 mark;
1015
1016 if (test_bit(RXRPC_CALL_RCVD_ABORT, &call->events))
1017 mark = RXRPC_SKB_MARK_REMOTE_ABORT;
1018 else
1019 mark = RXRPC_SKB_MARK_BUSY;
1020
1021 _debug("post abort/busy");
1022 rxrpc_clear_tx_window(call);
1023 if (rxrpc_post_message(call, mark, ECONNABORTED, true) < 0)
1024 goto no_mem;
1025
1026 clear_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
1027 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
1028 goto kill_ACKs;
1029 }
1030
1031 if (test_and_clear_bit(RXRPC_CALL_RCVD_ACKALL, &call->events)) {
1032 _debug("do implicit ackall");
1033 rxrpc_clear_tx_window(call);
1034 }
1035
1036 if (test_bit(RXRPC_CALL_LIFE_TIMER, &call->events)) {
1037 write_lock_bh(&call->state_lock);
1038 if (call->state <= RXRPC_CALL_COMPLETE) {
1039 call->state = RXRPC_CALL_LOCALLY_ABORTED;
1040 call->abort_code = RX_CALL_TIMEOUT;
1041 set_bit(RXRPC_CALL_ABORT, &call->events);
1042 }
1043 write_unlock_bh(&call->state_lock);
1044
1045 _debug("post timeout");
1046 if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
1047 ETIME, true) < 0)
1048 goto no_mem;
1049
1050 clear_bit(RXRPC_CALL_LIFE_TIMER, &call->events);
1051 goto kill_ACKs;
1052 }
1053
1054 /* deal with assorted inbound messages */
1055 if (!skb_queue_empty(&call->rx_queue)) {
1056 switch (rxrpc_process_rx_queue(call, &abort_code)) {
1057 case 0:
1058 case -EAGAIN:
1059 break;
1060 case -ENOMEM:
1061 goto no_mem;
1062 case -EKEYEXPIRED:
1063 case -EKEYREJECTED:
1064 case -EPROTO:
1065 rxrpc_abort_call(call, abort_code);
1066 goto kill_ACKs;
1067 }
1068 }
1069
1070 /* handle resending */
1071 if (test_and_clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
1072 rxrpc_resend_timer(call);
1073 if (test_and_clear_bit(RXRPC_CALL_RESEND, &call->events))
1074 rxrpc_resend(call);
1075
1076 /* consider sending an ordinary ACK */
1077 if (test_bit(RXRPC_CALL_ACK, &call->events)) {
1078 _debug("send ACK: window: %d - %d { %lx }",
1079 call->rx_data_eaten, call->ackr_win_top,
1080 call->ackr_window[0]);
1081
1082 if (call->state > RXRPC_CALL_SERVER_ACK_REQUEST &&
1083 call->ackr_reason != RXRPC_ACK_PING_RESPONSE) {
1084 /* ACK by sending reply DATA packet in this state */
1085 clear_bit(RXRPC_CALL_ACK, &call->events);
1086 goto maybe_reschedule;
1087 }
1088
1089 genbit = RXRPC_CALL_ACK;
1090
1091 acks = kzalloc(call->ackr_win_top - call->rx_data_eaten,
1092 GFP_NOFS);
1093 if (!acks)
1094 goto no_mem;
1095
1096 //hdr.flags = RXRPC_SLOW_START_OK;
1097 ack.bufferSpace = htons(8);
1098 ack.maxSkew = 0;
1099 ack.serial = 0;
1100 ack.reason = 0;
1101
1102 spin_lock_bh(&call->lock);
1103 ack.reason = call->ackr_reason;
1104 ack.serial = call->ackr_serial;
1105 ack.previousPacket = call->ackr_prev_seq;
1106 ack.firstPacket = htonl(call->rx_data_eaten + 1);
1107
1108 ack.nAcks = 0;
1109 for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) {
1110 nbit = loop * BITS_PER_LONG;
1111 for (bits = call->ackr_window[loop]; bits; bits >>= 1
1112 ) {
1113 _debug("- l=%d n=%d b=%lx", loop, nbit, bits);
1114 if (bits & 1) {
1115 acks[nbit] = RXRPC_ACK_TYPE_ACK;
1116 ack.nAcks = nbit + 1;
1117 }
1118 nbit++;
1119 }
1120 }
1121 call->ackr_reason = 0;
1122 spin_unlock_bh(&call->lock);
1123
1124 pad = 0;
1125
1126 iov[1].iov_base = &ack;
1127 iov[1].iov_len = sizeof(ack);
1128 iov[2].iov_base = acks;
1129 iov[2].iov_len = ack.nAcks;
1130 iov[3].iov_base = &pad;
1131 iov[3].iov_len = 3;
1132 iov[4].iov_base = &ackinfo;
1133 iov[4].iov_len = sizeof(ackinfo);
1134
1135 switch (ack.reason) {
1136 case RXRPC_ACK_REQUESTED:
1137 case RXRPC_ACK_DUPLICATE:
1138 case RXRPC_ACK_OUT_OF_SEQUENCE:
1139 case RXRPC_ACK_EXCEEDS_WINDOW:
1140 case RXRPC_ACK_NOSPACE:
1141 case RXRPC_ACK_PING:
1142 case RXRPC_ACK_PING_RESPONSE:
1143 goto send_ACK_with_skew;
1144 case RXRPC_ACK_DELAY:
1145 case RXRPC_ACK_IDLE:
1146 goto send_ACK;
1147 }
1148 }
1149
1150 /* handle completion of security negotiations on an incoming
1151 * connection */
1152 if (test_and_clear_bit(RXRPC_CALL_SECURED, &call->events)) {
1153 _debug("secured");
1154 spin_lock_bh(&call->lock);
1155
1156 if (call->state == RXRPC_CALL_SERVER_SECURING) {
1157 _debug("securing");
1158 write_lock(&call->conn->lock);
1159 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
1160 !test_bit(RXRPC_CALL_RELEASE, &call->events)) {
1161 _debug("not released");
1162 call->state = RXRPC_CALL_SERVER_ACCEPTING;
1163 list_move_tail(&call->accept_link,
1164 &call->socket->acceptq);
1165 }
1166 write_unlock(&call->conn->lock);
1167 read_lock(&call->state_lock);
1168 if (call->state < RXRPC_CALL_COMPLETE)
1169 set_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
1170 read_unlock(&call->state_lock);
1171 }
1172
1173 spin_unlock_bh(&call->lock);
1174 if (!test_bit(RXRPC_CALL_POST_ACCEPT, &call->events))
1175 goto maybe_reschedule;
1176 }
1177
1178 /* post a notification of an acceptable connection to the app */
1179 if (test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) {
1180 _debug("post accept");
1181 if (rxrpc_post_message(call, RXRPC_SKB_MARK_NEW_CALL,
1182 0, false) < 0)
1183 goto no_mem;
1184 clear_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
1185 goto maybe_reschedule;
1186 }
1187
1188 /* handle incoming call acceptance */
1189 if (test_and_clear_bit(RXRPC_CALL_ACCEPTED, &call->events)) {
1190 _debug("accepted");
1191 ASSERTCMP(call->rx_data_post, ==, 0);
1192 call->rx_data_post = 1;
1193 read_lock_bh(&call->state_lock);
1194 if (call->state < RXRPC_CALL_COMPLETE)
1195 set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
1196 read_unlock_bh(&call->state_lock);
1197 }
1198
1199 /* drain the out of sequence received packet queue into the packet Rx
1200 * queue */
1201 if (test_and_clear_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events)) {
1202 while (call->rx_data_post == call->rx_first_oos)
1203 if (rxrpc_drain_rx_oos_queue(call) < 0)
1204 break;
1205 goto maybe_reschedule;
1206 }
1207
1208 /* other events may have been raised since we started checking */
1209 goto maybe_reschedule;
1210
1211 send_ACK_with_skew:
1212 ack.maxSkew = htons(atomic_read(&call->conn->hi_serial) -
1213 ntohl(ack.serial));
1214 send_ACK:
1215 mtu = call->conn->trans->peer->if_mtu;
1216 mtu -= call->conn->trans->peer->hdrsize;
1217 ackinfo.maxMTU = htonl(mtu);
1218 ackinfo.rwind = htonl(rxrpc_rx_window_size);
1219
1220 /* permit the peer to send us jumbo packets if it wants to */
1221 ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
1222 ackinfo.jumbo_max = htonl(rxrpc_rx_jumbo_max);
1223
1224 hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
1225 _proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
1226 ntohl(hdr.serial),
1227 ntohs(ack.maxSkew),
1228 ntohl(ack.firstPacket),
1229 ntohl(ack.previousPacket),
1230 ntohl(ack.serial),
1231 rxrpc_acks(ack.reason),
1232 ack.nAcks);
1233
1234 del_timer_sync(&call->ack_timer);
1235 if (ack.nAcks > 0)
1236 set_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags);
1237 goto send_message_2;
1238
1239 send_message:
1240 _debug("send message");
1241
1242 hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
1243 _proto("Tx %s %%%u", rxrpc_pkts[hdr.type], ntohl(hdr.serial));
1244 send_message_2:
1245
1246 len = iov[0].iov_len;
1247 ioc = 1;
1248 if (iov[4].iov_len) {
1249 ioc = 5;
1250 len += iov[4].iov_len;
1251 len += iov[3].iov_len;
1252 len += iov[2].iov_len;
1253 len += iov[1].iov_len;
1254 } else if (iov[3].iov_len) {
1255 ioc = 4;
1256 len += iov[3].iov_len;
1257 len += iov[2].iov_len;
1258 len += iov[1].iov_len;
1259 } else if (iov[2].iov_len) {
1260 ioc = 3;
1261 len += iov[2].iov_len;
1262 len += iov[1].iov_len;
1263 } else if (iov[1].iov_len) {
1264 ioc = 2;
1265 len += iov[1].iov_len;
1266 }
1267
1268 ret = kernel_sendmsg(call->conn->trans->local->socket,
1269 &msg, iov, ioc, len);
1270 if (ret < 0) {
1271 _debug("sendmsg failed: %d", ret);
1272 read_lock_bh(&call->state_lock);
1273 if (call->state < RXRPC_CALL_DEAD)
1274 rxrpc_queue_call(call);
1275 read_unlock_bh(&call->state_lock);
1276 goto error;
1277 }
1278
1279 switch (genbit) {
1280 case RXRPC_CALL_ABORT:
1281 clear_bit(genbit, &call->events);
1282 clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
1283 goto kill_ACKs;
1284
1285 case RXRPC_CALL_ACK_FINAL:
1286 write_lock_bh(&call->state_lock);
1287 if (call->state == RXRPC_CALL_CLIENT_FINAL_ACK)
1288 call->state = RXRPC_CALL_COMPLETE;
1289 write_unlock_bh(&call->state_lock);
1290 goto kill_ACKs;
1291
1292 default:
1293 clear_bit(genbit, &call->events);
1294 switch (call->state) {
1295 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
1296 case RXRPC_CALL_CLIENT_RECV_REPLY:
1297 case RXRPC_CALL_SERVER_RECV_REQUEST:
1298 case RXRPC_CALL_SERVER_ACK_REQUEST:
1299 _debug("start ACK timer");
1300 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY,
1301 call->ackr_serial, false);
1302 default:
1303 break;
1304 }
1305 goto maybe_reschedule;
1306 }
1307
1308 kill_ACKs:
1309 del_timer_sync(&call->ack_timer);
1310 if (test_and_clear_bit(RXRPC_CALL_ACK_FINAL, &call->events))
1311 rxrpc_put_call(call);
1312 clear_bit(RXRPC_CALL_ACK, &call->events);
1313
1314 maybe_reschedule:
1315 if (call->events || !skb_queue_empty(&call->rx_queue)) {
1316 read_lock_bh(&call->state_lock);
1317 if (call->state < RXRPC_CALL_DEAD)
1318 rxrpc_queue_call(call);
1319 read_unlock_bh(&call->state_lock);
1320 }
1321
1322 /* don't leave aborted connections on the accept queue */
1323 if (call->state >= RXRPC_CALL_COMPLETE &&
1324 !list_empty(&call->accept_link)) {
1325 _debug("X unlinking once-pending call %p { e=%lx f=%lx c=%x }",
1326 call, call->events, call->flags,
1327 ntohl(call->conn->cid));
1328
1329 read_lock_bh(&call->state_lock);
1330 if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
1331 !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
1332 rxrpc_queue_call(call);
1333 read_unlock_bh(&call->state_lock);
1334 }
1335
1336 error:
1337 clear_bit(RXRPC_CALL_PROC_BUSY, &call->flags);
1338 kfree(acks);
1339
1340 /* because we don't want two CPUs both processing the work item for one
1341 * call at the same time, we use a flag to note when it's busy; however
1342 * this means there's a race between clearing the flag and setting the
1343 * work pending bit and the work item being processed again */
1344 if (call->events && !work_pending(&call->processor)) {
1345 _debug("jumpstart %x", ntohl(call->conn->cid));
1346 rxrpc_queue_call(call);
1347 }
1348
1349 _leave("");
1350 return;
1351
1352 no_mem:
1353 _debug("out of memory");
1354 goto maybe_reschedule;
1355 }
Linux with added FPC-III support