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configfs: fix race between dentry put and lookup
[linux-2.6.git] / fs / afs / rxrpc.c
blob8ad8c2a0703a120c2dde7f425225f1d515b13f0c
1 /* Maintain an RxRPC server socket to do AFS communications through
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/slab.h>
13 #include <net/sock.h>
14 #include <net/af_rxrpc.h>
15 #include <rxrpc/packet.h>
16 #include "internal.h"
17 #include "afs_cm.h"
18
19 static struct socket *afs_socket; /* my RxRPC socket */
20 static struct workqueue_struct *afs_async_calls;
21 static atomic_t afs_outstanding_calls;
22 static atomic_t afs_outstanding_skbs;
23
24 static void afs_wake_up_call_waiter(struct afs_call *);
25 static int afs_wait_for_call_to_complete(struct afs_call *);
26 static void afs_wake_up_async_call(struct afs_call *);
27 static int afs_dont_wait_for_call_to_complete(struct afs_call *);
28 static void afs_process_async_call(struct work_struct *);
29 static void afs_rx_interceptor(struct sock *, unsigned long, struct sk_buff *);
30 static int afs_deliver_cm_op_id(struct afs_call *, struct sk_buff *, bool);
31
32 /* synchronous call management */
33 const struct afs_wait_mode afs_sync_call = {
34 .rx_wakeup = afs_wake_up_call_waiter,
35 .wait = afs_wait_for_call_to_complete,
36 };
37
38 /* asynchronous call management */
39 const struct afs_wait_mode afs_async_call = {
40 .rx_wakeup = afs_wake_up_async_call,
41 .wait = afs_dont_wait_for_call_to_complete,
42 };
43
44 /* asynchronous incoming call management */
45 static const struct afs_wait_mode afs_async_incoming_call = {
46 .rx_wakeup = afs_wake_up_async_call,
47 };
48
49 /* asynchronous incoming call initial processing */
50 static const struct afs_call_type afs_RXCMxxxx = {
51 .name = "CB.xxxx",
52 .deliver = afs_deliver_cm_op_id,
53 .abort_to_error = afs_abort_to_error,
54 };
55
56 static void afs_collect_incoming_call(struct work_struct *);
57
58 static struct sk_buff_head afs_incoming_calls;
59 static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call);
60
61 /*
62 * open an RxRPC socket and bind it to be a server for callback notifications
63 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
64 */
65 int afs_open_socket(void)
66 {
67 struct sockaddr_rxrpc srx;
68 struct socket *socket;
69 int ret;
70
71 _enter("");
72
73 skb_queue_head_init(&afs_incoming_calls);
74
75 afs_async_calls = create_singlethread_workqueue("kafsd");
76 if (!afs_async_calls) {
77 _leave(" = -ENOMEM [wq]");
78 return -ENOMEM;
79 }
80
81 ret = sock_create_kern(AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
82 if (ret < 0) {
83 destroy_workqueue(afs_async_calls);
84 _leave(" = %d [socket]", ret);
85 return ret;
86 }
87
88 socket->sk->sk_allocation = GFP_NOFS;
89
90 /* bind the callback manager's address to make this a server socket */
91 srx.srx_family = AF_RXRPC;
92 srx.srx_service = CM_SERVICE;
93 srx.transport_type = SOCK_DGRAM;
94 srx.transport_len = sizeof(srx.transport.sin);
95 srx.transport.sin.sin_family = AF_INET;
96 srx.transport.sin.sin_port = htons(AFS_CM_PORT);
97 memset(&srx.transport.sin.sin_addr, 0,
98 sizeof(srx.transport.sin.sin_addr));
99
100 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
101 if (ret < 0) {
102 sock_release(socket);
103 destroy_workqueue(afs_async_calls);
104 _leave(" = %d [bind]", ret);
105 return ret;
106 }
107
108 rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor);
109
110 afs_socket = socket;
111 _leave(" = 0");
112 return 0;
113 }
114
115 /*
116 * close the RxRPC socket AFS was using
117 */
118 void afs_close_socket(void)
119 {
120 _enter("");
121
122 sock_release(afs_socket);
123
124 _debug("dework");
125 destroy_workqueue(afs_async_calls);
126
127 ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0);
128 ASSERTCMP(atomic_read(&afs_outstanding_calls), ==, 0);
129 _leave("");
130 }
131
132 /*
133 * note that the data in a socket buffer is now delivered and that the buffer
134 * should be freed
135 */
136 static void afs_data_delivered(struct sk_buff *skb)
137 {
138 if (!skb) {
139 _debug("DLVR NULL [%d]", atomic_read(&afs_outstanding_skbs));
140 dump_stack();
141 } else {
142 _debug("DLVR %p{%u} [%d]",
143 skb, skb->mark, atomic_read(&afs_outstanding_skbs));
144 if (atomic_dec_return(&afs_outstanding_skbs) == -1)
145 BUG();
146 rxrpc_kernel_data_delivered(skb);
147 }
148 }
149
150 /*
151 * free a socket buffer
152 */
153 static void afs_free_skb(struct sk_buff *skb)
154 {
155 if (!skb) {
156 _debug("FREE NULL [%d]", atomic_read(&afs_outstanding_skbs));
157 dump_stack();
158 } else {
159 _debug("FREE %p{%u} [%d]",
160 skb, skb->mark, atomic_read(&afs_outstanding_skbs));
161 if (atomic_dec_return(&afs_outstanding_skbs) == -1)
162 BUG();
163 rxrpc_kernel_free_skb(skb);
164 }
165 }
166
167 /*
168 * free a call
169 */
170 static void afs_free_call(struct afs_call *call)
171 {
172 _debug("DONE %p{%s} [%d]",
173 call, call->type->name, atomic_read(&afs_outstanding_calls));
174 if (atomic_dec_return(&afs_outstanding_calls) == -1)
175 BUG();
176
177 ASSERTCMP(call->rxcall, ==, NULL);
178 ASSERT(!work_pending(&call->async_work));
179 ASSERT(skb_queue_empty(&call->rx_queue));
180 ASSERT(call->type->name != NULL);
181
182 kfree(call->request);
183 kfree(call);
184 }
185
186 /*
187 * allocate a call with flat request and reply buffers
188 */
189 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
190 size_t request_size, size_t reply_size)
191 {
192 struct afs_call *call;
193
194 call = kzalloc(sizeof(*call), GFP_NOFS);
195 if (!call)
196 goto nomem_call;
197
198 _debug("CALL %p{%s} [%d]",
199 call, type->name, atomic_read(&afs_outstanding_calls));
200 atomic_inc(&afs_outstanding_calls);
201
202 call->type = type;
203 call->request_size = request_size;
204 call->reply_max = reply_size;
205
206 if (request_size) {
207 call->request = kmalloc(request_size, GFP_NOFS);
208 if (!call->request)
209 goto nomem_free;
210 }
211
212 if (reply_size) {
213 call->buffer = kmalloc(reply_size, GFP_NOFS);
214 if (!call->buffer)
215 goto nomem_free;
216 }
217
218 init_waitqueue_head(&call->waitq);
219 skb_queue_head_init(&call->rx_queue);
220 return call;
221
222 nomem_free:
223 afs_free_call(call);
224 nomem_call:
225 return NULL;
226 }
227
228 /*
229 * clean up a call with flat buffer
230 */
231 void afs_flat_call_destructor(struct afs_call *call)
232 {
233 _enter("");
234
235 kfree(call->request);
236 call->request = NULL;
237 kfree(call->buffer);
238 call->buffer = NULL;
239 }
240
241 /*
242 * attach the data from a bunch of pages on an inode to a call
243 */
244 static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
245 struct kvec *iov)
246 {
247 struct page *pages[8];
248 unsigned count, n, loop, offset, to;
249 pgoff_t first = call->first, last = call->last;
250 int ret;
251
252 _enter("");
253
254 offset = call->first_offset;
255 call->first_offset = 0;
256
257 do {
258 _debug("attach %lx-%lx", first, last);
259
260 count = last - first + 1;
261 if (count > ARRAY_SIZE(pages))
262 count = ARRAY_SIZE(pages);
263 n = find_get_pages_contig(call->mapping, first, count, pages);
264 ASSERTCMP(n, ==, count);
265
266 loop = 0;
267 do {
268 msg->msg_flags = 0;
269 to = PAGE_SIZE;
270 if (first + loop >= last)
271 to = call->last_to;
272 else
273 msg->msg_flags = MSG_MORE;
274 iov->iov_base = kmap(pages[loop]) + offset;
275 iov->iov_len = to - offset;
276 offset = 0;
277
278 _debug("- range %u-%u%s",
279 offset, to, msg->msg_flags ? " [more]" : "");
280 msg->msg_iov = (struct iovec *) iov;
281 msg->msg_iovlen = 1;
282
283 /* have to change the state *before* sending the last
284 * packet as RxRPC might give us the reply before it
285 * returns from sending the request */
286 if (first + loop >= last)
287 call->state = AFS_CALL_AWAIT_REPLY;
288 ret = rxrpc_kernel_send_data(call->rxcall, msg,
289 to - offset);
290 kunmap(pages[loop]);
291 if (ret < 0)
292 break;
293 } while (++loop < count);
294 first += count;
295
296 for (loop = 0; loop < count; loop++)
297 put_page(pages[loop]);
298 if (ret < 0)
299 break;
300 } while (first <= last);
301
302 _leave(" = %d", ret);
303 return ret;
304 }
305
306 /*
307 * initiate a call
308 */
309 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
310 const struct afs_wait_mode *wait_mode)
311 {
312 struct sockaddr_rxrpc srx;
313 struct rxrpc_call *rxcall;
314 struct msghdr msg;
315 struct kvec iov[1];
316 int ret;
317 struct sk_buff *skb;
318
319 _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
320
321 ASSERT(call->type != NULL);
322 ASSERT(call->type->name != NULL);
323
324 _debug("____MAKE %p{%s,%x} [%d]____",
325 call, call->type->name, key_serial(call->key),
326 atomic_read(&afs_outstanding_calls));
327
328 call->wait_mode = wait_mode;
329 INIT_WORK(&call->async_work, afs_process_async_call);
330
331 memset(&srx, 0, sizeof(srx));
332 srx.srx_family = AF_RXRPC;
333 srx.srx_service = call->service_id;
334 srx.transport_type = SOCK_DGRAM;
335 srx.transport_len = sizeof(srx.transport.sin);
336 srx.transport.sin.sin_family = AF_INET;
337 srx.transport.sin.sin_port = call->port;
338 memcpy(&srx.transport.sin.sin_addr, addr, 4);
339
340 /* create a call */
341 rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
342 (unsigned long) call, gfp);
343 call->key = NULL;
344 if (IS_ERR(rxcall)) {
345 ret = PTR_ERR(rxcall);
346 goto error_kill_call;
347 }
348
349 call->rxcall = rxcall;
350
351 /* send the request */
352 iov[0].iov_base = call->request;
353 iov[0].iov_len = call->request_size;
354
355 msg.msg_name = NULL;
356 msg.msg_namelen = 0;
357 msg.msg_iov = (struct iovec *) iov;
358 msg.msg_iovlen = 1;
359 msg.msg_control = NULL;
360 msg.msg_controllen = 0;
361 msg.msg_flags = (call->send_pages ? MSG_MORE : 0);
362
363 /* have to change the state *before* sending the last packet as RxRPC
364 * might give us the reply before it returns from sending the
365 * request */
366 if (!call->send_pages)
367 call->state = AFS_CALL_AWAIT_REPLY;
368 ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size);
369 if (ret < 0)
370 goto error_do_abort;
371
372 if (call->send_pages) {
373 ret = afs_send_pages(call, &msg, iov);
374 if (ret < 0)
375 goto error_do_abort;
376 }
377
378 /* at this point, an async call may no longer exist as it may have
379 * already completed */
380 return wait_mode->wait(call);
381
382 error_do_abort:
383 rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT);
384 while ((skb = skb_dequeue(&call->rx_queue)))
385 afs_free_skb(skb);
386 rxrpc_kernel_end_call(rxcall);
387 call->rxcall = NULL;
388 error_kill_call:
389 call->type->destructor(call);
390 afs_free_call(call);
391 _leave(" = %d", ret);
392 return ret;
393 }
394
395 /*
396 * handles intercepted messages that were arriving in the socket's Rx queue
397 * - called with the socket receive queue lock held to ensure message ordering
398 * - called with softirqs disabled
399 */
400 static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID,
401 struct sk_buff *skb)
402 {
403 struct afs_call *call = (struct afs_call *) user_call_ID;
404
405 _enter("%p,,%u", call, skb->mark);
406
407 _debug("ICPT %p{%u} [%d]",
408 skb, skb->mark, atomic_read(&afs_outstanding_skbs));
409
410 ASSERTCMP(sk, ==, afs_socket->sk);
411 atomic_inc(&afs_outstanding_skbs);
412
413 if (!call) {
414 /* its an incoming call for our callback service */
415 skb_queue_tail(&afs_incoming_calls, skb);
416 queue_work(afs_wq, &afs_collect_incoming_call_work);
417 } else {
418 /* route the messages directly to the appropriate call */
419 skb_queue_tail(&call->rx_queue, skb);
420 call->wait_mode->rx_wakeup(call);
421 }
422
423 _leave("");
424 }
425
426 /*
427 * deliver messages to a call
428 */
429 static void afs_deliver_to_call(struct afs_call *call)
430 {
431 struct sk_buff *skb;
432 bool last;
433 u32 abort_code;
434 int ret;
435
436 _enter("");
437
438 while ((call->state == AFS_CALL_AWAIT_REPLY ||
439 call->state == AFS_CALL_AWAIT_OP_ID ||
440 call->state == AFS_CALL_AWAIT_REQUEST ||
441 call->state == AFS_CALL_AWAIT_ACK) &&
442 (skb = skb_dequeue(&call->rx_queue))) {
443 switch (skb->mark) {
444 case RXRPC_SKB_MARK_DATA:
445 _debug("Rcv DATA");
446 last = rxrpc_kernel_is_data_last(skb);
447 ret = call->type->deliver(call, skb, last);
448 switch (ret) {
449 case 0:
450 if (last &&
451 call->state == AFS_CALL_AWAIT_REPLY)
452 call->state = AFS_CALL_COMPLETE;
453 break;
454 case -ENOTCONN:
455 abort_code = RX_CALL_DEAD;
456 goto do_abort;
457 case -ENOTSUPP:
458 abort_code = RX_INVALID_OPERATION;
459 goto do_abort;
460 default:
461 abort_code = RXGEN_CC_UNMARSHAL;
462 if (call->state != AFS_CALL_AWAIT_REPLY)
463 abort_code = RXGEN_SS_UNMARSHAL;
464 do_abort:
465 rxrpc_kernel_abort_call(call->rxcall,
466 abort_code);
467 call->error = ret;
468 call->state = AFS_CALL_ERROR;
469 break;
470 }
471 afs_data_delivered(skb);
472 skb = NULL;
473 continue;
474 case RXRPC_SKB_MARK_FINAL_ACK:
475 _debug("Rcv ACK");
476 call->state = AFS_CALL_COMPLETE;
477 break;
478 case RXRPC_SKB_MARK_BUSY:
479 _debug("Rcv BUSY");
480 call->error = -EBUSY;
481 call->state = AFS_CALL_BUSY;
482 break;
483 case RXRPC_SKB_MARK_REMOTE_ABORT:
484 abort_code = rxrpc_kernel_get_abort_code(skb);
485 call->error = call->type->abort_to_error(abort_code);
486 call->state = AFS_CALL_ABORTED;
487 _debug("Rcv ABORT %u -> %d", abort_code, call->error);
488 break;
489 case RXRPC_SKB_MARK_NET_ERROR:
490 call->error = -rxrpc_kernel_get_error_number(skb);
491 call->state = AFS_CALL_ERROR;
492 _debug("Rcv NET ERROR %d", call->error);
493 break;
494 case RXRPC_SKB_MARK_LOCAL_ERROR:
495 call->error = -rxrpc_kernel_get_error_number(skb);
496 call->state = AFS_CALL_ERROR;
497 _debug("Rcv LOCAL ERROR %d", call->error);
498 break;
499 default:
500 BUG();
501 break;
502 }
503
504 afs_free_skb(skb);
505 }
506
507 /* make sure the queue is empty if the call is done with (we might have
508 * aborted the call early because of an unmarshalling error) */
509 if (call->state >= AFS_CALL_COMPLETE) {
510 while ((skb = skb_dequeue(&call->rx_queue)))
511 afs_free_skb(skb);
512 if (call->incoming) {
513 rxrpc_kernel_end_call(call->rxcall);
514 call->rxcall = NULL;
515 call->type->destructor(call);
516 afs_free_call(call);
517 }
518 }
519
520 _leave("");
521 }
522
523 /*
524 * wait synchronously for a call to complete
525 */
526 static int afs_wait_for_call_to_complete(struct afs_call *call)
527 {
528 struct sk_buff *skb;
529 int ret;
530
531 DECLARE_WAITQUEUE(myself, current);
532
533 _enter("");
534
535 add_wait_queue(&call->waitq, &myself);
536 for (;;) {
537 set_current_state(TASK_INTERRUPTIBLE);
538
539 /* deliver any messages that are in the queue */
540 if (!skb_queue_empty(&call->rx_queue)) {
541 __set_current_state(TASK_RUNNING);
542 afs_deliver_to_call(call);
543 continue;
544 }
545
546 ret = call->error;
547 if (call->state >= AFS_CALL_COMPLETE)
548 break;
549 ret = -EINTR;
550 if (signal_pending(current))
551 break;
552 schedule();
553 }
554
555 remove_wait_queue(&call->waitq, &myself);
556 __set_current_state(TASK_RUNNING);
557
558 /* kill the call */
559 if (call->state < AFS_CALL_COMPLETE) {
560 _debug("call incomplete");
561 rxrpc_kernel_abort_call(call->rxcall, RX_CALL_DEAD);
562 while ((skb = skb_dequeue(&call->rx_queue)))
563 afs_free_skb(skb);
564 }
565
566 _debug("call complete");
567 rxrpc_kernel_end_call(call->rxcall);
568 call->rxcall = NULL;
569 call->type->destructor(call);
570 afs_free_call(call);
571 _leave(" = %d", ret);
572 return ret;
573 }
574
575 /*
576 * wake up a waiting call
577 */
578 static void afs_wake_up_call_waiter(struct afs_call *call)
579 {
580 wake_up(&call->waitq);
581 }
582
583 /*
584 * wake up an asynchronous call
585 */
586 static void afs_wake_up_async_call(struct afs_call *call)
587 {
588 _enter("");
589 queue_work(afs_async_calls, &call->async_work);
590 }
591
592 /*
593 * put a call into asynchronous mode
594 * - mustn't touch the call descriptor as the call my have completed by the
595 * time we get here
596 */
597 static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
598 {
599 _enter("");
600 return -EINPROGRESS;
601 }
602
603 /*
604 * delete an asynchronous call
605 */
606 static void afs_delete_async_call(struct work_struct *work)
607 {
608 struct afs_call *call =
609 container_of(work, struct afs_call, async_work);
610
611 _enter("");
612
613 afs_free_call(call);
614
615 _leave("");
616 }
617
618 /*
619 * perform processing on an asynchronous call
620 * - on a multiple-thread workqueue this work item may try to run on several
621 * CPUs at the same time
622 */
623 static void afs_process_async_call(struct work_struct *work)
624 {
625 struct afs_call *call =
626 container_of(work, struct afs_call, async_work);
627
628 _enter("");
629
630 if (!skb_queue_empty(&call->rx_queue))
631 afs_deliver_to_call(call);
632
633 if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) {
634 if (call->wait_mode->async_complete)
635 call->wait_mode->async_complete(call->reply,
636 call->error);
637 call->reply = NULL;
638
639 /* kill the call */
640 rxrpc_kernel_end_call(call->rxcall);
641 call->rxcall = NULL;
642 if (call->type->destructor)
643 call->type->destructor(call);
644
645 /* we can't just delete the call because the work item may be
646 * queued */
647 PREPARE_WORK(&call->async_work, afs_delete_async_call);
648 queue_work(afs_async_calls, &call->async_work);
649 }
650
651 _leave("");
652 }
653
654 /*
655 * empty a socket buffer into a flat reply buffer
656 */
657 void afs_transfer_reply(struct afs_call *call, struct sk_buff *skb)
658 {
659 size_t len = skb->len;
660
661 if (skb_copy_bits(skb, 0, call->buffer + call->reply_size, len) < 0)
662 BUG();
663 call->reply_size += len;
664 }
665
666 /*
667 * accept the backlog of incoming calls
668 */
669 static void afs_collect_incoming_call(struct work_struct *work)
670 {
671 struct rxrpc_call *rxcall;
672 struct afs_call *call = NULL;
673 struct sk_buff *skb;
674
675 while ((skb = skb_dequeue(&afs_incoming_calls))) {
676 _debug("new call");
677
678 /* don't need the notification */
679 afs_free_skb(skb);
680
681 if (!call) {
682 call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
683 if (!call) {
684 rxrpc_kernel_reject_call(afs_socket);
685 return;
686 }
687
688 INIT_WORK(&call->async_work, afs_process_async_call);
689 call->wait_mode = &afs_async_incoming_call;
690 call->type = &afs_RXCMxxxx;
691 init_waitqueue_head(&call->waitq);
692 skb_queue_head_init(&call->rx_queue);
693 call->state = AFS_CALL_AWAIT_OP_ID;
694
695 _debug("CALL %p{%s} [%d]",
696 call, call->type->name,
697 atomic_read(&afs_outstanding_calls));
698 atomic_inc(&afs_outstanding_calls);
699 }
700
701 rxcall = rxrpc_kernel_accept_call(afs_socket,
702 (unsigned long) call);
703 if (!IS_ERR(rxcall)) {
704 call->rxcall = rxcall;
705 call = NULL;
706 }
707 }
708
709 if (call)
710 afs_free_call(call);
711 }
712
713 /*
714 * grab the operation ID from an incoming cache manager call
715 */
716 static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb,
717 bool last)
718 {
719 size_t len = skb->len;
720 void *oibuf = (void *) &call->operation_ID;
721
722 _enter("{%u},{%zu},%d", call->offset, len, last);
723
724 ASSERTCMP(call->offset, <, 4);
725
726 /* the operation ID forms the first four bytes of the request data */
727 len = min_t(size_t, len, 4 - call->offset);
728 if (skb_copy_bits(skb, 0, oibuf + call->offset, len) < 0)
729 BUG();
730 if (!pskb_pull(skb, len))
731 BUG();
732 call->offset += len;
733
734 if (call->offset < 4) {
735 if (last) {
736 _leave(" = -EBADMSG [op ID short]");
737 return -EBADMSG;
738 }
739 _leave(" = 0 [incomplete]");
740 return 0;
741 }
742
743 call->state = AFS_CALL_AWAIT_REQUEST;
744
745 /* ask the cache manager to route the call (it'll change the call type
746 * if successful) */
747 if (!afs_cm_incoming_call(call))
748 return -ENOTSUPP;
749
750 /* pass responsibility for the remainer of this message off to the
751 * cache manager op */
752 return call->type->deliver(call, skb, last);
753 }
754
755 /*
756 * send an empty reply
757 */
758 void afs_send_empty_reply(struct afs_call *call)
759 {
760 struct msghdr msg;
761 struct iovec iov[1];
762
763 _enter("");
764
765 iov[0].iov_base = NULL;
766 iov[0].iov_len = 0;
767 msg.msg_name = NULL;
768 msg.msg_namelen = 0;
769 msg.msg_iov = iov;
770 msg.msg_iovlen = 0;
771 msg.msg_control = NULL;
772 msg.msg_controllen = 0;
773 msg.msg_flags = 0;
774
775 call->state = AFS_CALL_AWAIT_ACK;
776 switch (rxrpc_kernel_send_data(call->rxcall, &msg, 0)) {
777 case 0:
778 _leave(" [replied]");
779 return;
780
781 case -ENOMEM:
782 _debug("oom");
783 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
784 default:
785 rxrpc_kernel_end_call(call->rxcall);
786 call->rxcall = NULL;
787 call->type->destructor(call);
788 afs_free_call(call);
789 _leave(" [error]");
790 return;
791 }
792 }
793
794 /*
795 * send a simple reply
796 */
797 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
798 {
799 struct msghdr msg;
800 struct iovec iov[1];
801 int n;
802
803 _enter("");
804
805 iov[0].iov_base = (void *) buf;
806 iov[0].iov_len = len;
807 msg.msg_name = NULL;
808 msg.msg_namelen = 0;
809 msg.msg_iov = iov;
810 msg.msg_iovlen = 1;
811 msg.msg_control = NULL;
812 msg.msg_controllen = 0;
813 msg.msg_flags = 0;
814
815 call->state = AFS_CALL_AWAIT_ACK;
816 n = rxrpc_kernel_send_data(call->rxcall, &msg, len);
817 if (n >= 0) {
818 _leave(" [replied]");
819 return;
820 }
821 if (n == -ENOMEM) {
822 _debug("oom");
823 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
824 }
825 rxrpc_kernel_end_call(call->rxcall);
826 call->rxcall = NULL;
827 call->type->destructor(call);
828 afs_free_call(call);
829 _leave(" [error]");
830 }
831
832 /*
833 * extract a piece of data from the received data socket buffers
834 */
835 int afs_extract_data(struct afs_call *call, struct sk_buff *skb,
836 bool last, void *buf, size_t count)
837 {
838 size_t len = skb->len;
839
840 _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
841
842 ASSERTCMP(call->offset, <, count);
843
844 len = min_t(size_t, len, count - call->offset);
845 if (skb_copy_bits(skb, 0, buf + call->offset, len) < 0 ||
846 !pskb_pull(skb, len))
847 BUG();
848 call->offset += len;
849
850 if (call->offset < count) {
851 if (last) {
852 _leave(" = -EBADMSG [%d < %zu]", call->offset, count);
853 return -EBADMSG;
854 }
855 _leave(" = -EAGAIN");
856 return -EAGAIN;
857 }
858 return 0;
859 }
Linus' kernel tree