xref: /linux/fs/afs/rxrpc.c (revision 8a79db5e83a5d52c74e6f3c40d6f312cf899213e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Maintain an RxRPC server socket to do AFS communications through
3  *
4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/sched/signal.h>
10 
11 #include <net/sock.h>
12 #include <net/af_rxrpc.h>
13 #include "internal.h"
14 #include "afs_cm.h"
15 #include "protocol_yfs.h"
16 
17 struct workqueue_struct *afs_async_calls;
18 
19 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
20 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
21 static void afs_delete_async_call(struct work_struct *);
22 static void afs_process_async_call(struct work_struct *);
23 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
24 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
25 static int afs_deliver_cm_op_id(struct afs_call *);
26 
27 /* asynchronous incoming call initial processing */
28 static const struct afs_call_type afs_RXCMxxxx = {
29 	.name		= "CB.xxxx",
30 	.deliver	= afs_deliver_cm_op_id,
31 };
32 
33 /*
34  * open an RxRPC socket and bind it to be a server for callback notifications
35  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
36  */
37 int afs_open_socket(struct afs_net *net)
38 {
39 	struct sockaddr_rxrpc srx;
40 	struct socket *socket;
41 	unsigned int min_level;
42 	int ret;
43 
44 	_enter("");
45 
46 	ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
47 	if (ret < 0)
48 		goto error_1;
49 
50 	socket->sk->sk_allocation = GFP_NOFS;
51 
52 	/* bind the callback manager's address to make this a server socket */
53 	memset(&srx, 0, sizeof(srx));
54 	srx.srx_family			= AF_RXRPC;
55 	srx.srx_service			= CM_SERVICE;
56 	srx.transport_type		= SOCK_DGRAM;
57 	srx.transport_len		= sizeof(srx.transport.sin6);
58 	srx.transport.sin6.sin6_family	= AF_INET6;
59 	srx.transport.sin6.sin6_port	= htons(AFS_CM_PORT);
60 
61 	min_level = RXRPC_SECURITY_ENCRYPT;
62 	ret = kernel_setsockopt(socket, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
63 				(void *)&min_level, sizeof(min_level));
64 	if (ret < 0)
65 		goto error_2;
66 
67 	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
68 	if (ret == -EADDRINUSE) {
69 		srx.transport.sin6.sin6_port = 0;
70 		ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
71 	}
72 	if (ret < 0)
73 		goto error_2;
74 
75 	srx.srx_service = YFS_CM_SERVICE;
76 	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
77 	if (ret < 0)
78 		goto error_2;
79 
80 	/* Ideally, we'd turn on service upgrade here, but we can't because
81 	 * OpenAFS is buggy and leaks the userStatus field from packet to
82 	 * packet and between FS packets and CB packets - so if we try to do an
83 	 * upgrade on an FS packet, OpenAFS will leak that into the CB packet
84 	 * it sends back to us.
85 	 */
86 
87 	rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
88 					   afs_rx_discard_new_call);
89 
90 	ret = kernel_listen(socket, INT_MAX);
91 	if (ret < 0)
92 		goto error_2;
93 
94 	net->socket = socket;
95 	afs_charge_preallocation(&net->charge_preallocation_work);
96 	_leave(" = 0");
97 	return 0;
98 
99 error_2:
100 	sock_release(socket);
101 error_1:
102 	_leave(" = %d", ret);
103 	return ret;
104 }
105 
106 /*
107  * close the RxRPC socket AFS was using
108  */
109 void afs_close_socket(struct afs_net *net)
110 {
111 	_enter("");
112 
113 	kernel_listen(net->socket, 0);
114 	flush_workqueue(afs_async_calls);
115 
116 	if (net->spare_incoming_call) {
117 		afs_put_call(net->spare_incoming_call);
118 		net->spare_incoming_call = NULL;
119 	}
120 
121 	_debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
122 	wait_var_event(&net->nr_outstanding_calls,
123 		       !atomic_read(&net->nr_outstanding_calls));
124 	_debug("no outstanding calls");
125 
126 	kernel_sock_shutdown(net->socket, SHUT_RDWR);
127 	flush_workqueue(afs_async_calls);
128 	sock_release(net->socket);
129 
130 	_debug("dework");
131 	_leave("");
132 }
133 
134 /*
135  * Allocate a call.
136  */
137 static struct afs_call *afs_alloc_call(struct afs_net *net,
138 				       const struct afs_call_type *type,
139 				       gfp_t gfp)
140 {
141 	struct afs_call *call;
142 	int o;
143 
144 	call = kzalloc(sizeof(*call), gfp);
145 	if (!call)
146 		return NULL;
147 
148 	call->type = type;
149 	call->net = net;
150 	call->debug_id = atomic_inc_return(&rxrpc_debug_id);
151 	atomic_set(&call->usage, 1);
152 	INIT_WORK(&call->async_work, afs_process_async_call);
153 	init_waitqueue_head(&call->waitq);
154 	spin_lock_init(&call->state_lock);
155 	call->iter = &call->def_iter;
156 
157 	o = atomic_inc_return(&net->nr_outstanding_calls);
158 	trace_afs_call(call, afs_call_trace_alloc, 1, o,
159 		       __builtin_return_address(0));
160 	return call;
161 }
162 
163 /*
164  * Dispose of a reference on a call.
165  */
166 void afs_put_call(struct afs_call *call)
167 {
168 	struct afs_net *net = call->net;
169 	int n = atomic_dec_return(&call->usage);
170 	int o = atomic_read(&net->nr_outstanding_calls);
171 
172 	trace_afs_call(call, afs_call_trace_put, n + 1, o,
173 		       __builtin_return_address(0));
174 
175 	ASSERTCMP(n, >=, 0);
176 	if (n == 0) {
177 		ASSERT(!work_pending(&call->async_work));
178 		ASSERT(call->type->name != NULL);
179 
180 		if (call->rxcall) {
181 			rxrpc_kernel_end_call(net->socket, call->rxcall);
182 			call->rxcall = NULL;
183 		}
184 		if (call->type->destructor)
185 			call->type->destructor(call);
186 
187 		afs_put_server(call->net, call->server, afs_server_trace_put_call);
188 		afs_put_cb_interest(call->net, call->cbi);
189 		afs_put_addrlist(call->alist);
190 		kfree(call->request);
191 
192 		trace_afs_call(call, afs_call_trace_free, 0, o,
193 			       __builtin_return_address(0));
194 		kfree(call);
195 
196 		o = atomic_dec_return(&net->nr_outstanding_calls);
197 		if (o == 0)
198 			wake_up_var(&net->nr_outstanding_calls);
199 	}
200 }
201 
202 static struct afs_call *afs_get_call(struct afs_call *call,
203 				     enum afs_call_trace why)
204 {
205 	int u = atomic_inc_return(&call->usage);
206 
207 	trace_afs_call(call, why, u,
208 		       atomic_read(&call->net->nr_outstanding_calls),
209 		       __builtin_return_address(0));
210 	return call;
211 }
212 
213 /*
214  * Queue the call for actual work.
215  */
216 static void afs_queue_call_work(struct afs_call *call)
217 {
218 	if (call->type->work) {
219 		INIT_WORK(&call->work, call->type->work);
220 
221 		afs_get_call(call, afs_call_trace_work);
222 		if (!queue_work(afs_wq, &call->work))
223 			afs_put_call(call);
224 	}
225 }
226 
227 /*
228  * allocate a call with flat request and reply buffers
229  */
230 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
231 				     const struct afs_call_type *type,
232 				     size_t request_size, size_t reply_max)
233 {
234 	struct afs_call *call;
235 
236 	call = afs_alloc_call(net, type, GFP_NOFS);
237 	if (!call)
238 		goto nomem_call;
239 
240 	if (request_size) {
241 		call->request_size = request_size;
242 		call->request = kmalloc(request_size, GFP_NOFS);
243 		if (!call->request)
244 			goto nomem_free;
245 	}
246 
247 	if (reply_max) {
248 		call->reply_max = reply_max;
249 		call->buffer = kmalloc(reply_max, GFP_NOFS);
250 		if (!call->buffer)
251 			goto nomem_free;
252 	}
253 
254 	afs_extract_to_buf(call, call->reply_max);
255 	call->operation_ID = type->op;
256 	init_waitqueue_head(&call->waitq);
257 	return call;
258 
259 nomem_free:
260 	afs_put_call(call);
261 nomem_call:
262 	return NULL;
263 }
264 
265 /*
266  * clean up a call with flat buffer
267  */
268 void afs_flat_call_destructor(struct afs_call *call)
269 {
270 	_enter("");
271 
272 	kfree(call->request);
273 	call->request = NULL;
274 	kfree(call->buffer);
275 	call->buffer = NULL;
276 }
277 
278 #define AFS_BVEC_MAX 8
279 
280 /*
281  * Load the given bvec with the next few pages.
282  */
283 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
284 			  struct bio_vec *bv, pgoff_t first, pgoff_t last,
285 			  unsigned offset)
286 {
287 	struct page *pages[AFS_BVEC_MAX];
288 	unsigned int nr, n, i, to, bytes = 0;
289 
290 	nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
291 	n = find_get_pages_contig(call->mapping, first, nr, pages);
292 	ASSERTCMP(n, ==, nr);
293 
294 	msg->msg_flags |= MSG_MORE;
295 	for (i = 0; i < nr; i++) {
296 		to = PAGE_SIZE;
297 		if (first + i >= last) {
298 			to = call->last_to;
299 			msg->msg_flags &= ~MSG_MORE;
300 		}
301 		bv[i].bv_page = pages[i];
302 		bv[i].bv_len = to - offset;
303 		bv[i].bv_offset = offset;
304 		bytes += to - offset;
305 		offset = 0;
306 	}
307 
308 	iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
309 }
310 
311 /*
312  * Advance the AFS call state when the RxRPC call ends the transmit phase.
313  */
314 static void afs_notify_end_request_tx(struct sock *sock,
315 				      struct rxrpc_call *rxcall,
316 				      unsigned long call_user_ID)
317 {
318 	struct afs_call *call = (struct afs_call *)call_user_ID;
319 
320 	afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
321 }
322 
323 /*
324  * attach the data from a bunch of pages on an inode to a call
325  */
326 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
327 {
328 	struct bio_vec bv[AFS_BVEC_MAX];
329 	unsigned int bytes, nr, loop, offset;
330 	pgoff_t first = call->first, last = call->last;
331 	int ret;
332 
333 	offset = call->first_offset;
334 	call->first_offset = 0;
335 
336 	do {
337 		afs_load_bvec(call, msg, bv, first, last, offset);
338 		trace_afs_send_pages(call, msg, first, last, offset);
339 
340 		offset = 0;
341 		bytes = msg->msg_iter.count;
342 		nr = msg->msg_iter.nr_segs;
343 
344 		ret = rxrpc_kernel_send_data(call->net->socket, call->rxcall, msg,
345 					     bytes, afs_notify_end_request_tx);
346 		for (loop = 0; loop < nr; loop++)
347 			put_page(bv[loop].bv_page);
348 		if (ret < 0)
349 			break;
350 
351 		first += nr;
352 	} while (first <= last);
353 
354 	trace_afs_sent_pages(call, call->first, last, first, ret);
355 	return ret;
356 }
357 
358 /*
359  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
360  * error is stored into the call struct, which the caller must check for.
361  */
362 void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
363 {
364 	struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
365 	struct rxrpc_call *rxcall;
366 	struct msghdr msg;
367 	struct kvec iov[1];
368 	s64 tx_total_len;
369 	int ret;
370 
371 	_enter(",{%pISp},", &srx->transport);
372 
373 	ASSERT(call->type != NULL);
374 	ASSERT(call->type->name != NULL);
375 
376 	_debug("____MAKE %p{%s,%x} [%d]____",
377 	       call, call->type->name, key_serial(call->key),
378 	       atomic_read(&call->net->nr_outstanding_calls));
379 
380 	call->addr_ix = ac->index;
381 	call->alist = afs_get_addrlist(ac->alist);
382 
383 	/* Work out the length we're going to transmit.  This is awkward for
384 	 * calls such as FS.StoreData where there's an extra injection of data
385 	 * after the initial fixed part.
386 	 */
387 	tx_total_len = call->request_size;
388 	if (call->send_pages) {
389 		if (call->last == call->first) {
390 			tx_total_len += call->last_to - call->first_offset;
391 		} else {
392 			/* It looks mathematically like you should be able to
393 			 * combine the following lines with the ones above, but
394 			 * unsigned arithmetic is fun when it wraps...
395 			 */
396 			tx_total_len += PAGE_SIZE - call->first_offset;
397 			tx_total_len += call->last_to;
398 			tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
399 		}
400 	}
401 
402 	/* If the call is going to be asynchronous, we need an extra ref for
403 	 * the call to hold itself so the caller need not hang on to its ref.
404 	 */
405 	if (call->async)
406 		afs_get_call(call, afs_call_trace_get);
407 
408 	/* create a call */
409 	rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
410 					 (unsigned long)call,
411 					 tx_total_len, gfp,
412 					 (call->async ?
413 					  afs_wake_up_async_call :
414 					  afs_wake_up_call_waiter),
415 					 call->upgrade,
416 					 call->intr,
417 					 call->debug_id);
418 	if (IS_ERR(rxcall)) {
419 		ret = PTR_ERR(rxcall);
420 		call->error = ret;
421 		goto error_kill_call;
422 	}
423 
424 	call->rxcall = rxcall;
425 
426 	if (call->max_lifespan)
427 		rxrpc_kernel_set_max_life(call->net->socket, rxcall,
428 					  call->max_lifespan);
429 
430 	/* send the request */
431 	iov[0].iov_base	= call->request;
432 	iov[0].iov_len	= call->request_size;
433 
434 	msg.msg_name		= NULL;
435 	msg.msg_namelen		= 0;
436 	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
437 	msg.msg_control		= NULL;
438 	msg.msg_controllen	= 0;
439 	msg.msg_flags		= MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
440 
441 	ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
442 				     &msg, call->request_size,
443 				     afs_notify_end_request_tx);
444 	if (ret < 0)
445 		goto error_do_abort;
446 
447 	if (call->send_pages) {
448 		ret = afs_send_pages(call, &msg);
449 		if (ret < 0)
450 			goto error_do_abort;
451 	}
452 
453 	/* Note that at this point, we may have received the reply or an abort
454 	 * - and an asynchronous call may already have completed.
455 	 *
456 	 * afs_wait_for_call_to_complete(call, ac)
457 	 * must be called to synchronously clean up.
458 	 */
459 	return;
460 
461 error_do_abort:
462 	if (ret != -ECONNABORTED) {
463 		rxrpc_kernel_abort_call(call->net->socket, rxcall,
464 					RX_USER_ABORT, ret, "KSD");
465 	} else {
466 		iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
467 		rxrpc_kernel_recv_data(call->net->socket, rxcall,
468 				       &msg.msg_iter, false,
469 				       &call->abort_code, &call->service_id);
470 		ac->abort_code = call->abort_code;
471 		ac->responded = true;
472 	}
473 	call->error = ret;
474 	trace_afs_call_done(call);
475 error_kill_call:
476 	if (call->type->done)
477 		call->type->done(call);
478 
479 	/* We need to dispose of the extra ref we grabbed for an async call.
480 	 * The call, however, might be queued on afs_async_calls and we need to
481 	 * make sure we don't get any more notifications that might requeue it.
482 	 */
483 	if (call->rxcall) {
484 		rxrpc_kernel_end_call(call->net->socket, call->rxcall);
485 		call->rxcall = NULL;
486 	}
487 	if (call->async) {
488 		if (cancel_work_sync(&call->async_work))
489 			afs_put_call(call);
490 		afs_put_call(call);
491 	}
492 
493 	ac->error = ret;
494 	call->state = AFS_CALL_COMPLETE;
495 	_leave(" = %d", ret);
496 }
497 
498 /*
499  * deliver messages to a call
500  */
501 static void afs_deliver_to_call(struct afs_call *call)
502 {
503 	enum afs_call_state state;
504 	u32 abort_code, remote_abort = 0;
505 	int ret;
506 
507 	_enter("%s", call->type->name);
508 
509 	while (state = READ_ONCE(call->state),
510 	       state == AFS_CALL_CL_AWAIT_REPLY ||
511 	       state == AFS_CALL_SV_AWAIT_OP_ID ||
512 	       state == AFS_CALL_SV_AWAIT_REQUEST ||
513 	       state == AFS_CALL_SV_AWAIT_ACK
514 	       ) {
515 		if (state == AFS_CALL_SV_AWAIT_ACK) {
516 			iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
517 			ret = rxrpc_kernel_recv_data(call->net->socket,
518 						     call->rxcall, &call->def_iter,
519 						     false, &remote_abort,
520 						     &call->service_id);
521 			trace_afs_receive_data(call, &call->def_iter, false, ret);
522 
523 			if (ret == -EINPROGRESS || ret == -EAGAIN)
524 				return;
525 			if (ret < 0 || ret == 1) {
526 				if (ret == 1)
527 					ret = 0;
528 				goto call_complete;
529 			}
530 			return;
531 		}
532 
533 		if (!call->have_reply_time &&
534 		    rxrpc_kernel_get_reply_time(call->net->socket,
535 						call->rxcall,
536 						&call->reply_time))
537 			call->have_reply_time = true;
538 
539 		ret = call->type->deliver(call);
540 		state = READ_ONCE(call->state);
541 		switch (ret) {
542 		case 0:
543 			afs_queue_call_work(call);
544 			if (state == AFS_CALL_CL_PROC_REPLY) {
545 				if (call->cbi)
546 					set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
547 						&call->cbi->server->flags);
548 				goto call_complete;
549 			}
550 			ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
551 			goto done;
552 		case -EINPROGRESS:
553 		case -EAGAIN:
554 			goto out;
555 		case -ECONNABORTED:
556 			ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
557 			goto done;
558 		case -ENOTSUPP:
559 			abort_code = RXGEN_OPCODE;
560 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
561 						abort_code, ret, "KIV");
562 			goto local_abort;
563 		case -EIO:
564 			pr_err("kAFS: Call %u in bad state %u\n",
565 			       call->debug_id, state);
566 			/* Fall through */
567 		case -ENODATA:
568 		case -EBADMSG:
569 		case -EMSGSIZE:
570 			abort_code = RXGEN_CC_UNMARSHAL;
571 			if (state != AFS_CALL_CL_AWAIT_REPLY)
572 				abort_code = RXGEN_SS_UNMARSHAL;
573 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
574 						abort_code, ret, "KUM");
575 			goto local_abort;
576 		default:
577 			abort_code = RX_USER_ABORT;
578 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
579 						abort_code, ret, "KER");
580 			goto local_abort;
581 		}
582 	}
583 
584 done:
585 	if (call->type->done)
586 		call->type->done(call);
587 	if (state == AFS_CALL_COMPLETE && call->incoming)
588 		afs_put_call(call);
589 out:
590 	_leave("");
591 	return;
592 
593 local_abort:
594 	abort_code = 0;
595 call_complete:
596 	afs_set_call_complete(call, ret, remote_abort);
597 	state = AFS_CALL_COMPLETE;
598 	goto done;
599 }
600 
601 /*
602  * Wait synchronously for a call to complete and clean up the call struct.
603  */
604 long afs_wait_for_call_to_complete(struct afs_call *call,
605 				   struct afs_addr_cursor *ac)
606 {
607 	signed long rtt2, timeout;
608 	long ret;
609 	bool stalled = false;
610 	u64 rtt;
611 	u32 life, last_life;
612 	bool rxrpc_complete = false;
613 
614 	DECLARE_WAITQUEUE(myself, current);
615 
616 	_enter("");
617 
618 	ret = call->error;
619 	if (ret < 0)
620 		goto out;
621 
622 	rtt = rxrpc_kernel_get_rtt(call->net->socket, call->rxcall);
623 	rtt2 = nsecs_to_jiffies64(rtt) * 2;
624 	if (rtt2 < 2)
625 		rtt2 = 2;
626 
627 	timeout = rtt2;
628 	rxrpc_kernel_check_life(call->net->socket, call->rxcall, &last_life);
629 
630 	add_wait_queue(&call->waitq, &myself);
631 	for (;;) {
632 		set_current_state(TASK_UNINTERRUPTIBLE);
633 
634 		/* deliver any messages that are in the queue */
635 		if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
636 		    call->need_attention) {
637 			call->need_attention = false;
638 			__set_current_state(TASK_RUNNING);
639 			afs_deliver_to_call(call);
640 			timeout = rtt2;
641 			continue;
642 		}
643 
644 		if (afs_check_call_state(call, AFS_CALL_COMPLETE))
645 			break;
646 
647 		if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall, &life)) {
648 			/* rxrpc terminated the call. */
649 			rxrpc_complete = true;
650 			break;
651 		}
652 
653 		if (call->intr && timeout == 0 &&
654 		    life == last_life && signal_pending(current)) {
655 			if (stalled)
656 				break;
657 			__set_current_state(TASK_RUNNING);
658 			rxrpc_kernel_probe_life(call->net->socket, call->rxcall);
659 			timeout = rtt2;
660 			stalled = true;
661 			continue;
662 		}
663 
664 		if (life != last_life) {
665 			timeout = rtt2;
666 			last_life = life;
667 			stalled = false;
668 		}
669 
670 		timeout = schedule_timeout(timeout);
671 	}
672 
673 	remove_wait_queue(&call->waitq, &myself);
674 	__set_current_state(TASK_RUNNING);
675 
676 	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
677 		if (rxrpc_complete) {
678 			afs_set_call_complete(call, call->error, call->abort_code);
679 		} else {
680 			/* Kill off the call if it's still live. */
681 			_debug("call interrupted");
682 			if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
683 						    RX_USER_ABORT, -EINTR, "KWI"))
684 				afs_set_call_complete(call, -EINTR, 0);
685 		}
686 	}
687 
688 	spin_lock_bh(&call->state_lock);
689 	ac->abort_code = call->abort_code;
690 	ac->error = call->error;
691 	spin_unlock_bh(&call->state_lock);
692 
693 	ret = ac->error;
694 	switch (ret) {
695 	case 0:
696 		ret = call->ret0;
697 		call->ret0 = 0;
698 
699 		/* Fall through */
700 	case -ECONNABORTED:
701 		ac->responded = true;
702 		break;
703 	}
704 
705 out:
706 	_debug("call complete");
707 	afs_put_call(call);
708 	_leave(" = %p", (void *)ret);
709 	return ret;
710 }
711 
712 /*
713  * wake up a waiting call
714  */
715 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
716 				    unsigned long call_user_ID)
717 {
718 	struct afs_call *call = (struct afs_call *)call_user_ID;
719 
720 	call->need_attention = true;
721 	wake_up(&call->waitq);
722 }
723 
724 /*
725  * wake up an asynchronous call
726  */
727 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
728 				   unsigned long call_user_ID)
729 {
730 	struct afs_call *call = (struct afs_call *)call_user_ID;
731 	int u;
732 
733 	trace_afs_notify_call(rxcall, call);
734 	call->need_attention = true;
735 
736 	u = atomic_fetch_add_unless(&call->usage, 1, 0);
737 	if (u != 0) {
738 		trace_afs_call(call, afs_call_trace_wake, u,
739 			       atomic_read(&call->net->nr_outstanding_calls),
740 			       __builtin_return_address(0));
741 
742 		if (!queue_work(afs_async_calls, &call->async_work))
743 			afs_put_call(call);
744 	}
745 }
746 
747 /*
748  * Delete an asynchronous call.  The work item carries a ref to the call struct
749  * that we need to release.
750  */
751 static void afs_delete_async_call(struct work_struct *work)
752 {
753 	struct afs_call *call = container_of(work, struct afs_call, async_work);
754 
755 	_enter("");
756 
757 	afs_put_call(call);
758 
759 	_leave("");
760 }
761 
762 /*
763  * Perform I/O processing on an asynchronous call.  The work item carries a ref
764  * to the call struct that we either need to release or to pass on.
765  */
766 static void afs_process_async_call(struct work_struct *work)
767 {
768 	struct afs_call *call = container_of(work, struct afs_call, async_work);
769 
770 	_enter("");
771 
772 	if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
773 		call->need_attention = false;
774 		afs_deliver_to_call(call);
775 	}
776 
777 	if (call->state == AFS_CALL_COMPLETE) {
778 		/* We have two refs to release - one from the alloc and one
779 		 * queued with the work item - and we can't just deallocate the
780 		 * call because the work item may be queued again.
781 		 */
782 		call->async_work.func = afs_delete_async_call;
783 		if (!queue_work(afs_async_calls, &call->async_work))
784 			afs_put_call(call);
785 	}
786 
787 	afs_put_call(call);
788 	_leave("");
789 }
790 
791 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
792 {
793 	struct afs_call *call = (struct afs_call *)user_call_ID;
794 
795 	call->rxcall = rxcall;
796 }
797 
798 /*
799  * Charge the incoming call preallocation.
800  */
801 void afs_charge_preallocation(struct work_struct *work)
802 {
803 	struct afs_net *net =
804 		container_of(work, struct afs_net, charge_preallocation_work);
805 	struct afs_call *call = net->spare_incoming_call;
806 
807 	for (;;) {
808 		if (!call) {
809 			call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
810 			if (!call)
811 				break;
812 
813 			call->async = true;
814 			call->state = AFS_CALL_SV_AWAIT_OP_ID;
815 			init_waitqueue_head(&call->waitq);
816 			afs_extract_to_tmp(call);
817 		}
818 
819 		if (rxrpc_kernel_charge_accept(net->socket,
820 					       afs_wake_up_async_call,
821 					       afs_rx_attach,
822 					       (unsigned long)call,
823 					       GFP_KERNEL,
824 					       call->debug_id) < 0)
825 			break;
826 		call = NULL;
827 	}
828 	net->spare_incoming_call = call;
829 }
830 
831 /*
832  * Discard a preallocated call when a socket is shut down.
833  */
834 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
835 				    unsigned long user_call_ID)
836 {
837 	struct afs_call *call = (struct afs_call *)user_call_ID;
838 
839 	call->rxcall = NULL;
840 	afs_put_call(call);
841 }
842 
843 /*
844  * Notification of an incoming call.
845  */
846 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
847 			    unsigned long user_call_ID)
848 {
849 	struct afs_net *net = afs_sock2net(sk);
850 
851 	queue_work(afs_wq, &net->charge_preallocation_work);
852 }
853 
854 /*
855  * Grab the operation ID from an incoming cache manager call.  The socket
856  * buffer is discarded on error or if we don't yet have sufficient data.
857  */
858 static int afs_deliver_cm_op_id(struct afs_call *call)
859 {
860 	int ret;
861 
862 	_enter("{%zu}", iov_iter_count(call->iter));
863 
864 	/* the operation ID forms the first four bytes of the request data */
865 	ret = afs_extract_data(call, true);
866 	if (ret < 0)
867 		return ret;
868 
869 	call->operation_ID = ntohl(call->tmp);
870 	afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
871 
872 	/* ask the cache manager to route the call (it'll change the call type
873 	 * if successful) */
874 	if (!afs_cm_incoming_call(call))
875 		return -ENOTSUPP;
876 
877 	trace_afs_cb_call(call);
878 
879 	/* pass responsibility for the remainer of this message off to the
880 	 * cache manager op */
881 	return call->type->deliver(call);
882 }
883 
884 /*
885  * Advance the AFS call state when an RxRPC service call ends the transmit
886  * phase.
887  */
888 static void afs_notify_end_reply_tx(struct sock *sock,
889 				    struct rxrpc_call *rxcall,
890 				    unsigned long call_user_ID)
891 {
892 	struct afs_call *call = (struct afs_call *)call_user_ID;
893 
894 	afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
895 }
896 
897 /*
898  * send an empty reply
899  */
900 void afs_send_empty_reply(struct afs_call *call)
901 {
902 	struct afs_net *net = call->net;
903 	struct msghdr msg;
904 
905 	_enter("");
906 
907 	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
908 
909 	msg.msg_name		= NULL;
910 	msg.msg_namelen		= 0;
911 	iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
912 	msg.msg_control		= NULL;
913 	msg.msg_controllen	= 0;
914 	msg.msg_flags		= 0;
915 
916 	switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
917 				       afs_notify_end_reply_tx)) {
918 	case 0:
919 		_leave(" [replied]");
920 		return;
921 
922 	case -ENOMEM:
923 		_debug("oom");
924 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
925 					RX_USER_ABORT, -ENOMEM, "KOO");
926 		/* Fall through */
927 	default:
928 		_leave(" [error]");
929 		return;
930 	}
931 }
932 
933 /*
934  * send a simple reply
935  */
936 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
937 {
938 	struct afs_net *net = call->net;
939 	struct msghdr msg;
940 	struct kvec iov[1];
941 	int n;
942 
943 	_enter("");
944 
945 	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
946 
947 	iov[0].iov_base		= (void *) buf;
948 	iov[0].iov_len		= len;
949 	msg.msg_name		= NULL;
950 	msg.msg_namelen		= 0;
951 	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
952 	msg.msg_control		= NULL;
953 	msg.msg_controllen	= 0;
954 	msg.msg_flags		= 0;
955 
956 	n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
957 				   afs_notify_end_reply_tx);
958 	if (n >= 0) {
959 		/* Success */
960 		_leave(" [replied]");
961 		return;
962 	}
963 
964 	if (n == -ENOMEM) {
965 		_debug("oom");
966 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
967 					RX_USER_ABORT, -ENOMEM, "KOO");
968 	}
969 	_leave(" [error]");
970 }
971 
972 /*
973  * Extract a piece of data from the received data socket buffers.
974  */
975 int afs_extract_data(struct afs_call *call, bool want_more)
976 {
977 	struct afs_net *net = call->net;
978 	struct iov_iter *iter = call->iter;
979 	enum afs_call_state state;
980 	u32 remote_abort = 0;
981 	int ret;
982 
983 	_enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
984 
985 	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
986 				     want_more, &remote_abort,
987 				     &call->service_id);
988 	if (ret == 0 || ret == -EAGAIN)
989 		return ret;
990 
991 	state = READ_ONCE(call->state);
992 	if (ret == 1) {
993 		switch (state) {
994 		case AFS_CALL_CL_AWAIT_REPLY:
995 			afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
996 			break;
997 		case AFS_CALL_SV_AWAIT_REQUEST:
998 			afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
999 			break;
1000 		case AFS_CALL_COMPLETE:
1001 			kdebug("prem complete %d", call->error);
1002 			return afs_io_error(call, afs_io_error_extract);
1003 		default:
1004 			break;
1005 		}
1006 		return 0;
1007 	}
1008 
1009 	afs_set_call_complete(call, ret, remote_abort);
1010 	return ret;
1011 }
1012 
1013 /*
1014  * Log protocol error production.
1015  */
1016 noinline int afs_protocol_error(struct afs_call *call, int error,
1017 				enum afs_eproto_cause cause)
1018 {
1019 	trace_afs_protocol_error(call, error, cause);
1020 	return error;
1021 }
1022