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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / fs / afs / rxrpc.c
blobe1126659f043f0c445cc19fa9524cc5d96afd36a
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 <linux/sched/signal.h>
14
15 #include <net/sock.h>
16 #include <net/af_rxrpc.h>
17 #include "internal.h"
18 #include "afs_cm.h"
19
20 struct workqueue_struct *afs_async_calls;
21
22 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
23 static long afs_wait_for_call_to_complete(struct afs_call *, struct afs_addr_cursor *);
24 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
25 static void afs_process_async_call(struct work_struct *);
26 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
27 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
28 static int afs_deliver_cm_op_id(struct afs_call *);
29
30 /* asynchronous incoming call initial processing */
31 static const struct afs_call_type afs_RXCMxxxx = {
32 .name = "CB.xxxx",
33 .deliver = afs_deliver_cm_op_id,
34 };
35
36 /*
37 * open an RxRPC socket and bind it to be a server for callback notifications
38 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
39 */
40 int afs_open_socket(struct afs_net *net)
41 {
42 struct sockaddr_rxrpc srx;
43 struct socket *socket;
44 int ret;
45
46 _enter("");
47
48 ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
49 if (ret < 0)
50 goto error_1;
51
52 socket->sk->sk_allocation = GFP_NOFS;
53
54 /* bind the callback manager's address to make this a server socket */
55 memset(&srx, 0, sizeof(srx));
56 srx.srx_family = AF_RXRPC;
57 srx.srx_service = CM_SERVICE;
58 srx.transport_type = SOCK_DGRAM;
59 srx.transport_len = sizeof(srx.transport.sin6);
60 srx.transport.sin6.sin6_family = AF_INET6;
61 srx.transport.sin6.sin6_port = htons(AFS_CM_PORT);
62
63 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
64 if (ret == -EADDRINUSE) {
65 srx.transport.sin6.sin6_port = 0;
66 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
67 }
68 if (ret < 0)
69 goto error_2;
70
71 rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
72 afs_rx_discard_new_call);
73
74 ret = kernel_listen(socket, INT_MAX);
75 if (ret < 0)
76 goto error_2;
77
78 net->socket = socket;
79 afs_charge_preallocation(&net->charge_preallocation_work);
80 _leave(" = 0");
81 return 0;
82
83 error_2:
84 sock_release(socket);
85 error_1:
86 _leave(" = %d", ret);
87 return ret;
88 }
89
90 /*
91 * close the RxRPC socket AFS was using
92 */
93 void afs_close_socket(struct afs_net *net)
94 {
95 _enter("");
96
97 kernel_listen(net->socket, 0);
98 flush_workqueue(afs_async_calls);
99
100 if (net->spare_incoming_call) {
101 afs_put_call(net->spare_incoming_call);
102 net->spare_incoming_call = NULL;
103 }
104
105 _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
106 wait_on_atomic_t(&net->nr_outstanding_calls, atomic_t_wait,
107 TASK_UNINTERRUPTIBLE);
108 _debug("no outstanding calls");
109
110 kernel_sock_shutdown(net->socket, SHUT_RDWR);
111 flush_workqueue(afs_async_calls);
112 sock_release(net->socket);
113
114 _debug("dework");
115 _leave("");
116 }
117
118 /*
119 * Allocate a call.
120 */
121 static struct afs_call *afs_alloc_call(struct afs_net *net,
122 const struct afs_call_type *type,
123 gfp_t gfp)
124 {
125 struct afs_call *call;
126 int o;
127
128 call = kzalloc(sizeof(*call), gfp);
129 if (!call)
130 return NULL;
131
132 call->type = type;
133 call->net = net;
134 atomic_set(&call->usage, 1);
135 INIT_WORK(&call->async_work, afs_process_async_call);
136 init_waitqueue_head(&call->waitq);
137 spin_lock_init(&call->state_lock);
138
139 o = atomic_inc_return(&net->nr_outstanding_calls);
140 trace_afs_call(call, afs_call_trace_alloc, 1, o,
141 __builtin_return_address(0));
142 return call;
143 }
144
145 /*
146 * Dispose of a reference on a call.
147 */
148 void afs_put_call(struct afs_call *call)
149 {
150 struct afs_net *net = call->net;
151 int n = atomic_dec_return(&call->usage);
152 int o = atomic_read(&net->nr_outstanding_calls);
153
154 trace_afs_call(call, afs_call_trace_put, n + 1, o,
155 __builtin_return_address(0));
156
157 ASSERTCMP(n, >=, 0);
158 if (n == 0) {
159 ASSERT(!work_pending(&call->async_work));
160 ASSERT(call->type->name != NULL);
161
162 if (call->rxcall) {
163 rxrpc_kernel_end_call(net->socket, call->rxcall);
164 call->rxcall = NULL;
165 }
166 if (call->type->destructor)
167 call->type->destructor(call);
168
169 afs_put_server(call->net, call->cm_server);
170 afs_put_cb_interest(call->net, call->cbi);
171 kfree(call->request);
172 kfree(call);
173
174 o = atomic_dec_return(&net->nr_outstanding_calls);
175 trace_afs_call(call, afs_call_trace_free, 0, o,
176 __builtin_return_address(0));
177 if (o == 0)
178 wake_up_atomic_t(&net->nr_outstanding_calls);
179 }
180 }
181
182 /*
183 * Queue the call for actual work. Returns 0 unconditionally for convenience.
184 */
185 int afs_queue_call_work(struct afs_call *call)
186 {
187 int u = atomic_inc_return(&call->usage);
188
189 trace_afs_call(call, afs_call_trace_work, u,
190 atomic_read(&call->net->nr_outstanding_calls),
191 __builtin_return_address(0));
192
193 INIT_WORK(&call->work, call->type->work);
194
195 if (!queue_work(afs_wq, &call->work))
196 afs_put_call(call);
197 return 0;
198 }
199
200 /*
201 * allocate a call with flat request and reply buffers
202 */
203 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
204 const struct afs_call_type *type,
205 size_t request_size, size_t reply_max)
206 {
207 struct afs_call *call;
208
209 call = afs_alloc_call(net, type, GFP_NOFS);
210 if (!call)
211 goto nomem_call;
212
213 if (request_size) {
214 call->request_size = request_size;
215 call->request = kmalloc(request_size, GFP_NOFS);
216 if (!call->request)
217 goto nomem_free;
218 }
219
220 if (reply_max) {
221 call->reply_max = reply_max;
222 call->buffer = kmalloc(reply_max, GFP_NOFS);
223 if (!call->buffer)
224 goto nomem_free;
225 }
226
227 call->operation_ID = type->op;
228 init_waitqueue_head(&call->waitq);
229 return call;
230
231 nomem_free:
232 afs_put_call(call);
233 nomem_call:
234 return NULL;
235 }
236
237 /*
238 * clean up a call with flat buffer
239 */
240 void afs_flat_call_destructor(struct afs_call *call)
241 {
242 _enter("");
243
244 kfree(call->request);
245 call->request = NULL;
246 kfree(call->buffer);
247 call->buffer = NULL;
248 }
249
250 #define AFS_BVEC_MAX 8
251
252 /*
253 * Load the given bvec with the next few pages.
254 */
255 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
256 struct bio_vec *bv, pgoff_t first, pgoff_t last,
257 unsigned offset)
258 {
259 struct page *pages[AFS_BVEC_MAX];
260 unsigned int nr, n, i, to, bytes = 0;
261
262 nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
263 n = find_get_pages_contig(call->mapping, first, nr, pages);
264 ASSERTCMP(n, ==, nr);
265
266 msg->msg_flags |= MSG_MORE;
267 for (i = 0; i < nr; i++) {
268 to = PAGE_SIZE;
269 if (first + i >= last) {
270 to = call->last_to;
271 msg->msg_flags &= ~MSG_MORE;
272 }
273 bv[i].bv_page = pages[i];
274 bv[i].bv_len = to - offset;
275 bv[i].bv_offset = offset;
276 bytes += to - offset;
277 offset = 0;
278 }
279
280 iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
281 }
282
283 /*
284 * Advance the AFS call state when the RxRPC call ends the transmit phase.
285 */
286 static void afs_notify_end_request_tx(struct sock *sock,
287 struct rxrpc_call *rxcall,
288 unsigned long call_user_ID)
289 {
290 struct afs_call *call = (struct afs_call *)call_user_ID;
291
292 afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
293 }
294
295 /*
296 * attach the data from a bunch of pages on an inode to a call
297 */
298 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
299 {
300 struct bio_vec bv[AFS_BVEC_MAX];
301 unsigned int bytes, nr, loop, offset;
302 pgoff_t first = call->first, last = call->last;
303 int ret;
304
305 offset = call->first_offset;
306 call->first_offset = 0;
307
308 do {
309 afs_load_bvec(call, msg, bv, first, last, offset);
310 trace_afs_send_pages(call, msg, first, last, offset);
311
312 offset = 0;
313 bytes = msg->msg_iter.count;
314 nr = msg->msg_iter.nr_segs;
315
316 ret = rxrpc_kernel_send_data(call->net->socket, call->rxcall, msg,
317 bytes, afs_notify_end_request_tx);
318 for (loop = 0; loop < nr; loop++)
319 put_page(bv[loop].bv_page);
320 if (ret < 0)
321 break;
322
323 first += nr;
324 } while (first <= last);
325
326 trace_afs_sent_pages(call, call->first, last, first, ret);
327 return ret;
328 }
329
330 /*
331 * initiate a call
332 */
333 long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
334 gfp_t gfp, bool async)
335 {
336 struct sockaddr_rxrpc *srx = ac->addr;
337 struct rxrpc_call *rxcall;
338 struct msghdr msg;
339 struct kvec iov[1];
340 size_t offset;
341 s64 tx_total_len;
342 int ret;
343
344 _enter(",{%pISp},", &srx->transport);
345
346 ASSERT(call->type != NULL);
347 ASSERT(call->type->name != NULL);
348
349 _debug("____MAKE %p{%s,%x} [%d]____",
350 call, call->type->name, key_serial(call->key),
351 atomic_read(&call->net->nr_outstanding_calls));
352
353 call->async = async;
354
355 /* Work out the length we're going to transmit. This is awkward for
356 * calls such as FS.StoreData where there's an extra injection of data
357 * after the initial fixed part.
358 */
359 tx_total_len = call->request_size;
360 if (call->send_pages) {
361 if (call->last == call->first) {
362 tx_total_len += call->last_to - call->first_offset;
363 } else {
364 /* It looks mathematically like you should be able to
365 * combine the following lines with the ones above, but
366 * unsigned arithmetic is fun when it wraps...
367 */
368 tx_total_len += PAGE_SIZE - call->first_offset;
369 tx_total_len += call->last_to;
370 tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
371 }
372 }
373
374 /* create a call */
375 rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
376 (unsigned long)call,
377 tx_total_len, gfp,
378 (async ?
379 afs_wake_up_async_call :
380 afs_wake_up_call_waiter),
381 call->upgrade);
382 if (IS_ERR(rxcall)) {
383 ret = PTR_ERR(rxcall);
384 goto error_kill_call;
385 }
386
387 call->rxcall = rxcall;
388
389 /* send the request */
390 iov[0].iov_base = call->request;
391 iov[0].iov_len = call->request_size;
392
393 msg.msg_name = NULL;
394 msg.msg_namelen = 0;
395 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
396 call->request_size);
397 msg.msg_control = NULL;
398 msg.msg_controllen = 0;
399 msg.msg_flags = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
400
401 ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
402 &msg, call->request_size,
403 afs_notify_end_request_tx);
404 if (ret < 0)
405 goto error_do_abort;
406
407 if (call->send_pages) {
408 ret = afs_send_pages(call, &msg);
409 if (ret < 0)
410 goto error_do_abort;
411 }
412
413 /* at this point, an async call may no longer exist as it may have
414 * already completed */
415 if (call->async)
416 return -EINPROGRESS;
417
418 return afs_wait_for_call_to_complete(call, ac);
419
420 error_do_abort:
421 call->state = AFS_CALL_COMPLETE;
422 if (ret != -ECONNABORTED) {
423 rxrpc_kernel_abort_call(call->net->socket, rxcall,
424 RX_USER_ABORT, ret, "KSD");
425 } else {
426 offset = 0;
427 rxrpc_kernel_recv_data(call->net->socket, rxcall, NULL,
428 0, &offset, false, &call->abort_code,
429 &call->service_id);
430 ac->abort_code = call->abort_code;
431 ac->responded = true;
432 }
433 call->error = ret;
434 trace_afs_call_done(call);
435 error_kill_call:
436 afs_put_call(call);
437 ac->error = ret;
438 _leave(" = %d", ret);
439 return ret;
440 }
441
442 /*
443 * deliver messages to a call
444 */
445 static void afs_deliver_to_call(struct afs_call *call)
446 {
447 enum afs_call_state state;
448 u32 abort_code, remote_abort = 0;
449 int ret;
450
451 _enter("%s", call->type->name);
452
453 while (state = READ_ONCE(call->state),
454 state == AFS_CALL_CL_AWAIT_REPLY ||
455 state == AFS_CALL_SV_AWAIT_OP_ID ||
456 state == AFS_CALL_SV_AWAIT_REQUEST ||
457 state == AFS_CALL_SV_AWAIT_ACK
458 ) {
459 if (state == AFS_CALL_SV_AWAIT_ACK) {
460 size_t offset = 0;
461 ret = rxrpc_kernel_recv_data(call->net->socket,
462 call->rxcall,
463 NULL, 0, &offset, false,
464 &remote_abort,
465 &call->service_id);
466 trace_afs_recv_data(call, 0, offset, false, ret);
467
468 if (ret == -EINPROGRESS || ret == -EAGAIN)
469 return;
470 if (ret < 0 || ret == 1) {
471 if (ret == 1)
472 ret = 0;
473 goto call_complete;
474 }
475 return;
476 }
477
478 ret = call->type->deliver(call);
479 state = READ_ONCE(call->state);
480 switch (ret) {
481 case 0:
482 if (state == AFS_CALL_CL_PROC_REPLY)
483 goto call_complete;
484 ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
485 goto done;
486 case -EINPROGRESS:
487 case -EAGAIN:
488 goto out;
489 case -EIO:
490 case -ECONNABORTED:
491 ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
492 goto done;
493 case -ENOTCONN:
494 abort_code = RX_CALL_DEAD;
495 rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
496 abort_code, ret, "KNC");
497 goto local_abort;
498 case -ENOTSUPP:
499 abort_code = RXGEN_OPCODE;
500 rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
501 abort_code, ret, "KIV");
502 goto local_abort;
503 case -ENODATA:
504 case -EBADMSG:
505 case -EMSGSIZE:
506 default:
507 abort_code = RXGEN_CC_UNMARSHAL;
508 if (state != AFS_CALL_CL_AWAIT_REPLY)
509 abort_code = RXGEN_SS_UNMARSHAL;
510 rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
511 abort_code, -EBADMSG, "KUM");
512 goto local_abort;
513 }
514 }
515
516 done:
517 if (state == AFS_CALL_COMPLETE && call->incoming)
518 afs_put_call(call);
519 out:
520 _leave("");
521 return;
522
523 local_abort:
524 abort_code = 0;
525 call_complete:
526 afs_set_call_complete(call, ret, remote_abort);
527 state = AFS_CALL_COMPLETE;
528 goto done;
529 }
530
531 /*
532 * wait synchronously for a call to complete
533 */
534 static long afs_wait_for_call_to_complete(struct afs_call *call,
535 struct afs_addr_cursor *ac)
536 {
537 signed long rtt2, timeout;
538 long ret;
539 u64 rtt;
540 u32 life, last_life;
541
542 DECLARE_WAITQUEUE(myself, current);
543
544 _enter("");
545
546 rtt = rxrpc_kernel_get_rtt(call->net->socket, call->rxcall);
547 rtt2 = nsecs_to_jiffies64(rtt) * 2;
548 if (rtt2 < 2)
549 rtt2 = 2;
550
551 timeout = rtt2;
552 last_life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
553
554 add_wait_queue(&call->waitq, &myself);
555 for (;;) {
556 set_current_state(TASK_UNINTERRUPTIBLE);
557
558 /* deliver any messages that are in the queue */
559 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
560 call->need_attention) {
561 call->need_attention = false;
562 __set_current_state(TASK_RUNNING);
563 afs_deliver_to_call(call);
564 continue;
565 }
566
567 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
568 break;
569
570 life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
571 if (timeout == 0 &&
572 life == last_life && signal_pending(current))
573 break;
574
575 if (life != last_life) {
576 timeout = rtt2;
577 last_life = life;
578 }
579
580 timeout = schedule_timeout(timeout);
581 }
582
583 remove_wait_queue(&call->waitq, &myself);
584 __set_current_state(TASK_RUNNING);
585
586 /* Kill off the call if it's still live. */
587 if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
588 _debug("call interrupted");
589 if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
590 RX_USER_ABORT, -EINTR, "KWI"))
591 afs_set_call_complete(call, -EINTR, 0);
592 }
593
594 spin_lock_bh(&call->state_lock);
595 ac->abort_code = call->abort_code;
596 ac->error = call->error;
597 spin_unlock_bh(&call->state_lock);
598
599 ret = ac->error;
600 switch (ret) {
601 case 0:
602 if (call->ret_reply0) {
603 ret = (long)call->reply[0];
604 call->reply[0] = NULL;
605 }
606 /* Fall through */
607 case -ECONNABORTED:
608 ac->responded = true;
609 break;
610 }
611
612 _debug("call complete");
613 afs_put_call(call);
614 _leave(" = %p", (void *)ret);
615 return ret;
616 }
617
618 /*
619 * wake up a waiting call
620 */
621 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
622 unsigned long call_user_ID)
623 {
624 struct afs_call *call = (struct afs_call *)call_user_ID;
625
626 call->need_attention = true;
627 wake_up(&call->waitq);
628 }
629
630 /*
631 * wake up an asynchronous call
632 */
633 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
634 unsigned long call_user_ID)
635 {
636 struct afs_call *call = (struct afs_call *)call_user_ID;
637 int u;
638
639 trace_afs_notify_call(rxcall, call);
640 call->need_attention = true;
641
642 u = __atomic_add_unless(&call->usage, 1, 0);
643 if (u != 0) {
644 trace_afs_call(call, afs_call_trace_wake, u,
645 atomic_read(&call->net->nr_outstanding_calls),
646 __builtin_return_address(0));
647
648 if (!queue_work(afs_async_calls, &call->async_work))
649 afs_put_call(call);
650 }
651 }
652
653 /*
654 * Delete an asynchronous call. The work item carries a ref to the call struct
655 * that we need to release.
656 */
657 static void afs_delete_async_call(struct work_struct *work)
658 {
659 struct afs_call *call = container_of(work, struct afs_call, async_work);
660
661 _enter("");
662
663 afs_put_call(call);
664
665 _leave("");
666 }
667
668 /*
669 * Perform I/O processing on an asynchronous call. The work item carries a ref
670 * to the call struct that we either need to release or to pass on.
671 */
672 static void afs_process_async_call(struct work_struct *work)
673 {
674 struct afs_call *call = container_of(work, struct afs_call, async_work);
675
676 _enter("");
677
678 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
679 call->need_attention = false;
680 afs_deliver_to_call(call);
681 }
682
683 if (call->state == AFS_CALL_COMPLETE) {
684 call->reply[0] = NULL;
685
686 /* We have two refs to release - one from the alloc and one
687 * queued with the work item - and we can't just deallocate the
688 * call because the work item may be queued again.
689 */
690 call->async_work.func = afs_delete_async_call;
691 if (!queue_work(afs_async_calls, &call->async_work))
692 afs_put_call(call);
693 }
694
695 afs_put_call(call);
696 _leave("");
697 }
698
699 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
700 {
701 struct afs_call *call = (struct afs_call *)user_call_ID;
702
703 call->rxcall = rxcall;
704 }
705
706 /*
707 * Charge the incoming call preallocation.
708 */
709 void afs_charge_preallocation(struct work_struct *work)
710 {
711 struct afs_net *net =
712 container_of(work, struct afs_net, charge_preallocation_work);
713 struct afs_call *call = net->spare_incoming_call;
714
715 for (;;) {
716 if (!call) {
717 call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
718 if (!call)
719 break;
720
721 call->async = true;
722 call->state = AFS_CALL_SV_AWAIT_OP_ID;
723 init_waitqueue_head(&call->waitq);
724 }
725
726 if (rxrpc_kernel_charge_accept(net->socket,
727 afs_wake_up_async_call,
728 afs_rx_attach,
729 (unsigned long)call,
730 GFP_KERNEL) < 0)
731 break;
732 call = NULL;
733 }
734 net->spare_incoming_call = call;
735 }
736
737 /*
738 * Discard a preallocated call when a socket is shut down.
739 */
740 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
741 unsigned long user_call_ID)
742 {
743 struct afs_call *call = (struct afs_call *)user_call_ID;
744
745 call->rxcall = NULL;
746 afs_put_call(call);
747 }
748
749 /*
750 * Notification of an incoming call.
751 */
752 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
753 unsigned long user_call_ID)
754 {
755 struct afs_net *net = afs_sock2net(sk);
756
757 queue_work(afs_wq, &net->charge_preallocation_work);
758 }
759
760 /*
761 * Grab the operation ID from an incoming cache manager call. The socket
762 * buffer is discarded on error or if we don't yet have sufficient data.
763 */
764 static int afs_deliver_cm_op_id(struct afs_call *call)
765 {
766 int ret;
767
768 _enter("{%zu}", call->offset);
769
770 ASSERTCMP(call->offset, <, 4);
771
772 /* the operation ID forms the first four bytes of the request data */
773 ret = afs_extract_data(call, &call->tmp, 4, true);
774 if (ret < 0)
775 return ret;
776
777 call->operation_ID = ntohl(call->tmp);
778 afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
779 call->offset = 0;
780
781 /* ask the cache manager to route the call (it'll change the call type
782 * if successful) */
783 if (!afs_cm_incoming_call(call))
784 return -ENOTSUPP;
785
786 trace_afs_cb_call(call);
787
788 /* pass responsibility for the remainer of this message off to the
789 * cache manager op */
790 return call->type->deliver(call);
791 }
792
793 /*
794 * Advance the AFS call state when an RxRPC service call ends the transmit
795 * phase.
796 */
797 static void afs_notify_end_reply_tx(struct sock *sock,
798 struct rxrpc_call *rxcall,
799 unsigned long call_user_ID)
800 {
801 struct afs_call *call = (struct afs_call *)call_user_ID;
802
803 afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
804 }
805
806 /*
807 * send an empty reply
808 */
809 void afs_send_empty_reply(struct afs_call *call)
810 {
811 struct afs_net *net = call->net;
812 struct msghdr msg;
813
814 _enter("");
815
816 rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
817
818 msg.msg_name = NULL;
819 msg.msg_namelen = 0;
820 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
821 msg.msg_control = NULL;
822 msg.msg_controllen = 0;
823 msg.msg_flags = 0;
824
825 switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
826 afs_notify_end_reply_tx)) {
827 case 0:
828 _leave(" [replied]");
829 return;
830
831 case -ENOMEM:
832 _debug("oom");
833 rxrpc_kernel_abort_call(net->socket, call->rxcall,
834 RX_USER_ABORT, -ENOMEM, "KOO");
835 default:
836 _leave(" [error]");
837 return;
838 }
839 }
840
841 /*
842 * send a simple reply
843 */
844 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
845 {
846 struct afs_net *net = call->net;
847 struct msghdr msg;
848 struct kvec iov[1];
849 int n;
850
851 _enter("");
852
853 rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
854
855 iov[0].iov_base = (void *) buf;
856 iov[0].iov_len = len;
857 msg.msg_name = NULL;
858 msg.msg_namelen = 0;
859 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
860 msg.msg_control = NULL;
861 msg.msg_controllen = 0;
862 msg.msg_flags = 0;
863
864 n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
865 afs_notify_end_reply_tx);
866 if (n >= 0) {
867 /* Success */
868 _leave(" [replied]");
869 return;
870 }
871
872 if (n == -ENOMEM) {
873 _debug("oom");
874 rxrpc_kernel_abort_call(net->socket, call->rxcall,
875 RX_USER_ABORT, -ENOMEM, "KOO");
876 }
877 _leave(" [error]");
878 }
879
880 /*
881 * Extract a piece of data from the received data socket buffers.
882 */
883 int afs_extract_data(struct afs_call *call, void *buf, size_t count,
884 bool want_more)
885 {
886 struct afs_net *net = call->net;
887 enum afs_call_state state;
888 u32 remote_abort = 0;
889 int ret;
890
891 _enter("{%s,%zu},,%zu,%d",
892 call->type->name, call->offset, count, want_more);
893
894 ASSERTCMP(call->offset, <=, count);
895
896 ret = rxrpc_kernel_recv_data(net->socket, call->rxcall,
897 buf, count, &call->offset,
898 want_more, &remote_abort,
899 &call->service_id);
900 trace_afs_recv_data(call, count, call->offset, want_more, ret);
901 if (ret == 0 || ret == -EAGAIN)
902 return ret;
903
904 state = READ_ONCE(call->state);
905 if (ret == 1) {
906 switch (state) {
907 case AFS_CALL_CL_AWAIT_REPLY:
908 afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
909 break;
910 case AFS_CALL_SV_AWAIT_REQUEST:
911 afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
912 break;
913 case AFS_CALL_COMPLETE:
914 kdebug("prem complete %d", call->error);
915 return -EIO;
916 default:
917 break;
918 }
919 return 0;
920 }
921
922 afs_set_call_complete(call, ret, remote_abort);
923 return ret;
924 }
CRIS linux kernel tree