xref: /kernel/linux/linux-5.10/fs/afs/rxrpc.c (revision 8c2ecf20)
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
17struct workqueue_struct *afs_async_calls;
18
19static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
20static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
21static void afs_process_async_call(struct work_struct *);
22static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
23static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
24static int afs_deliver_cm_op_id(struct afs_call *);
25
26/* asynchronous incoming call initial processing */
27static const struct afs_call_type afs_RXCMxxxx = {
28	.name		= "CB.xxxx",
29	.deliver	= afs_deliver_cm_op_id,
30};
31
32/*
33 * open an RxRPC socket and bind it to be a server for callback notifications
34 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
35 */
36int afs_open_socket(struct afs_net *net)
37{
38	struct sockaddr_rxrpc srx;
39	struct socket *socket;
40	int ret;
41
42	_enter("");
43
44	ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
45	if (ret < 0)
46		goto error_1;
47
48	socket->sk->sk_allocation = GFP_NOFS;
49
50	/* bind the callback manager's address to make this a server socket */
51	memset(&srx, 0, sizeof(srx));
52	srx.srx_family			= AF_RXRPC;
53	srx.srx_service			= CM_SERVICE;
54	srx.transport_type		= SOCK_DGRAM;
55	srx.transport_len		= sizeof(srx.transport.sin6);
56	srx.transport.sin6.sin6_family	= AF_INET6;
57	srx.transport.sin6.sin6_port	= htons(AFS_CM_PORT);
58
59	ret = rxrpc_sock_set_min_security_level(socket->sk,
60						RXRPC_SECURITY_ENCRYPT);
61	if (ret < 0)
62		goto error_2;
63
64	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
65	if (ret == -EADDRINUSE) {
66		srx.transport.sin6.sin6_port = 0;
67		ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
68	}
69	if (ret < 0)
70		goto error_2;
71
72	srx.srx_service = YFS_CM_SERVICE;
73	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
74	if (ret < 0)
75		goto error_2;
76
77	/* Ideally, we'd turn on service upgrade here, but we can't because
78	 * OpenAFS is buggy and leaks the userStatus field from packet to
79	 * packet and between FS packets and CB packets - so if we try to do an
80	 * upgrade on an FS packet, OpenAFS will leak that into the CB packet
81	 * it sends back to us.
82	 */
83
84	rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
85					   afs_rx_discard_new_call);
86
87	ret = kernel_listen(socket, INT_MAX);
88	if (ret < 0)
89		goto error_2;
90
91	net->socket = socket;
92	afs_charge_preallocation(&net->charge_preallocation_work);
93	_leave(" = 0");
94	return 0;
95
96error_2:
97	sock_release(socket);
98error_1:
99	_leave(" = %d", ret);
100	return ret;
101}
102
103/*
104 * close the RxRPC socket AFS was using
105 */
106void afs_close_socket(struct afs_net *net)
107{
108	_enter("");
109
110	kernel_listen(net->socket, 0);
111	flush_workqueue(afs_async_calls);
112
113	if (net->spare_incoming_call) {
114		afs_put_call(net->spare_incoming_call);
115		net->spare_incoming_call = NULL;
116	}
117
118	_debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
119	wait_var_event(&net->nr_outstanding_calls,
120		       !atomic_read(&net->nr_outstanding_calls));
121	_debug("no outstanding calls");
122
123	kernel_sock_shutdown(net->socket, SHUT_RDWR);
124	flush_workqueue(afs_async_calls);
125	sock_release(net->socket);
126
127	_debug("dework");
128	_leave("");
129}
130
131/*
132 * Allocate a call.
133 */
134static struct afs_call *afs_alloc_call(struct afs_net *net,
135				       const struct afs_call_type *type,
136				       gfp_t gfp)
137{
138	struct afs_call *call;
139	int o;
140
141	call = kzalloc(sizeof(*call), gfp);
142	if (!call)
143		return NULL;
144
145	call->type = type;
146	call->net = net;
147	call->debug_id = atomic_inc_return(&rxrpc_debug_id);
148	atomic_set(&call->usage, 1);
149	INIT_WORK(&call->async_work, afs_process_async_call);
150	init_waitqueue_head(&call->waitq);
151	spin_lock_init(&call->state_lock);
152	call->iter = &call->def_iter;
153
154	o = atomic_inc_return(&net->nr_outstanding_calls);
155	trace_afs_call(call, afs_call_trace_alloc, 1, o,
156		       __builtin_return_address(0));
157	return call;
158}
159
160/*
161 * Dispose of a reference on a call.
162 */
163void afs_put_call(struct afs_call *call)
164{
165	struct afs_net *net = call->net;
166	int n = atomic_dec_return(&call->usage);
167	int o = atomic_read(&net->nr_outstanding_calls);
168
169	trace_afs_call(call, afs_call_trace_put, n, o,
170		       __builtin_return_address(0));
171
172	ASSERTCMP(n, >=, 0);
173	if (n == 0) {
174		ASSERT(!work_pending(&call->async_work));
175		ASSERT(call->type->name != NULL);
176
177		if (call->rxcall) {
178			rxrpc_kernel_end_call(net->socket, call->rxcall);
179			call->rxcall = NULL;
180		}
181		if (call->type->destructor)
182			call->type->destructor(call);
183
184		afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);
185		afs_put_addrlist(call->alist);
186		kfree(call->request);
187
188		trace_afs_call(call, afs_call_trace_free, 0, o,
189			       __builtin_return_address(0));
190		kfree(call);
191
192		o = atomic_dec_return(&net->nr_outstanding_calls);
193		if (o == 0)
194			wake_up_var(&net->nr_outstanding_calls);
195	}
196}
197
198static struct afs_call *afs_get_call(struct afs_call *call,
199				     enum afs_call_trace why)
200{
201	int u = atomic_inc_return(&call->usage);
202
203	trace_afs_call(call, why, u,
204		       atomic_read(&call->net->nr_outstanding_calls),
205		       __builtin_return_address(0));
206	return call;
207}
208
209/*
210 * Queue the call for actual work.
211 */
212static void afs_queue_call_work(struct afs_call *call)
213{
214	if (call->type->work) {
215		INIT_WORK(&call->work, call->type->work);
216
217		afs_get_call(call, afs_call_trace_work);
218		if (!queue_work(afs_wq, &call->work))
219			afs_put_call(call);
220	}
221}
222
223/*
224 * allocate a call with flat request and reply buffers
225 */
226struct afs_call *afs_alloc_flat_call(struct afs_net *net,
227				     const struct afs_call_type *type,
228				     size_t request_size, size_t reply_max)
229{
230	struct afs_call *call;
231
232	call = afs_alloc_call(net, type, GFP_NOFS);
233	if (!call)
234		goto nomem_call;
235
236	if (request_size) {
237		call->request_size = request_size;
238		call->request = kmalloc(request_size, GFP_NOFS);
239		if (!call->request)
240			goto nomem_free;
241	}
242
243	if (reply_max) {
244		call->reply_max = reply_max;
245		call->buffer = kmalloc(reply_max, GFP_NOFS);
246		if (!call->buffer)
247			goto nomem_free;
248	}
249
250	afs_extract_to_buf(call, call->reply_max);
251	call->operation_ID = type->op;
252	init_waitqueue_head(&call->waitq);
253	return call;
254
255nomem_free:
256	afs_put_call(call);
257nomem_call:
258	return NULL;
259}
260
261/*
262 * clean up a call with flat buffer
263 */
264void afs_flat_call_destructor(struct afs_call *call)
265{
266	_enter("");
267
268	kfree(call->request);
269	call->request = NULL;
270	kfree(call->buffer);
271	call->buffer = NULL;
272}
273
274#define AFS_BVEC_MAX 8
275
276/*
277 * Load the given bvec with the next few pages.
278 */
279static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
280			  struct bio_vec *bv, pgoff_t first, pgoff_t last,
281			  unsigned offset)
282{
283	struct afs_operation *op = call->op;
284	struct page *pages[AFS_BVEC_MAX];
285	unsigned int nr, n, i, to, bytes = 0;
286
287	nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
288	n = find_get_pages_contig(op->store.mapping, first, nr, pages);
289	ASSERTCMP(n, ==, nr);
290
291	msg->msg_flags |= MSG_MORE;
292	for (i = 0; i < nr; i++) {
293		to = PAGE_SIZE;
294		if (first + i >= last) {
295			to = op->store.last_to;
296			msg->msg_flags &= ~MSG_MORE;
297		}
298		bv[i].bv_page = pages[i];
299		bv[i].bv_len = to - offset;
300		bv[i].bv_offset = offset;
301		bytes += to - offset;
302		offset = 0;
303	}
304
305	iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
306}
307
308/*
309 * Advance the AFS call state when the RxRPC call ends the transmit phase.
310 */
311static void afs_notify_end_request_tx(struct sock *sock,
312				      struct rxrpc_call *rxcall,
313				      unsigned long call_user_ID)
314{
315	struct afs_call *call = (struct afs_call *)call_user_ID;
316
317	afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
318}
319
320/*
321 * attach the data from a bunch of pages on an inode to a call
322 */
323static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
324{
325	struct afs_operation *op = call->op;
326	struct bio_vec bv[AFS_BVEC_MAX];
327	unsigned int bytes, nr, loop, offset;
328	pgoff_t first = op->store.first, last = op->store.last;
329	int ret;
330
331	offset = op->store.first_offset;
332	op->store.first_offset = 0;
333
334	do {
335		afs_load_bvec(call, msg, bv, first, last, offset);
336		trace_afs_send_pages(call, msg, first, last, offset);
337
338		offset = 0;
339		bytes = msg->msg_iter.count;
340		nr = msg->msg_iter.nr_segs;
341
342		ret = rxrpc_kernel_send_data(op->net->socket, call->rxcall, msg,
343					     bytes, afs_notify_end_request_tx);
344		for (loop = 0; loop < nr; loop++)
345			put_page(bv[loop].bv_page);
346		if (ret < 0)
347			break;
348
349		first += nr;
350	} while (first <= last);
351
352	trace_afs_sent_pages(call, op->store.first, last, first, ret);
353	return ret;
354}
355
356/*
357 * Initiate a call and synchronously queue up the parameters for dispatch.  Any
358 * error is stored into the call struct, which the caller must check for.
359 */
360void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
361{
362	struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
363	struct rxrpc_call *rxcall;
364	struct msghdr msg;
365	struct kvec iov[1];
366	s64 tx_total_len;
367	int ret;
368
369	_enter(",{%pISp},", &srx->transport);
370
371	ASSERT(call->type != NULL);
372	ASSERT(call->type->name != NULL);
373
374	_debug("____MAKE %p{%s,%x} [%d]____",
375	       call, call->type->name, key_serial(call->key),
376	       atomic_read(&call->net->nr_outstanding_calls));
377
378	call->addr_ix = ac->index;
379	call->alist = afs_get_addrlist(ac->alist);
380
381	/* Work out the length we're going to transmit.  This is awkward for
382	 * calls such as FS.StoreData where there's an extra injection of data
383	 * after the initial fixed part.
384	 */
385	tx_total_len = call->request_size;
386	if (call->send_pages) {
387		struct afs_operation *op = call->op;
388
389		if (op->store.last == op->store.first) {
390			tx_total_len += op->store.last_to - op->store.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 - op->store.first_offset;
397			tx_total_len += op->store.last_to;
398			tx_total_len += (op->store.last - op->store.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		call->drop_ref = true;
408	}
409
410	/* create a call */
411	rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
412					 (unsigned long)call,
413					 tx_total_len, gfp,
414					 (call->async ?
415					  afs_wake_up_async_call :
416					  afs_wake_up_call_waiter),
417					 call->upgrade,
418					 (call->intr ? RXRPC_PREINTERRUPTIBLE :
419					  RXRPC_UNINTERRUPTIBLE),
420					 call->debug_id);
421	if (IS_ERR(rxcall)) {
422		ret = PTR_ERR(rxcall);
423		call->error = ret;
424		goto error_kill_call;
425	}
426
427	call->rxcall = rxcall;
428
429	if (call->max_lifespan)
430		rxrpc_kernel_set_max_life(call->net->socket, rxcall,
431					  call->max_lifespan);
432	call->issue_time = ktime_get_real();
433
434	/* send the request */
435	iov[0].iov_base	= call->request;
436	iov[0].iov_len	= call->request_size;
437
438	msg.msg_name		= NULL;
439	msg.msg_namelen		= 0;
440	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
441	msg.msg_control		= NULL;
442	msg.msg_controllen	= 0;
443	msg.msg_flags		= MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
444
445	ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
446				     &msg, call->request_size,
447				     afs_notify_end_request_tx);
448	if (ret < 0)
449		goto error_do_abort;
450
451	if (call->send_pages) {
452		ret = afs_send_pages(call, &msg);
453		if (ret < 0)
454			goto error_do_abort;
455	}
456
457	/* Note that at this point, we may have received the reply or an abort
458	 * - and an asynchronous call may already have completed.
459	 *
460	 * afs_wait_for_call_to_complete(call, ac)
461	 * must be called to synchronously clean up.
462	 */
463	return;
464
465error_do_abort:
466	if (ret != -ECONNABORTED) {
467		rxrpc_kernel_abort_call(call->net->socket, rxcall,
468					RX_USER_ABORT, ret, "KSD");
469	} else {
470		iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
471		rxrpc_kernel_recv_data(call->net->socket, rxcall,
472				       &msg.msg_iter, false,
473				       &call->abort_code, &call->service_id);
474		ac->abort_code = call->abort_code;
475		ac->responded = true;
476	}
477	call->error = ret;
478	trace_afs_call_done(call);
479error_kill_call:
480	if (call->type->done)
481		call->type->done(call);
482
483	/* We need to dispose of the extra ref we grabbed for an async call.
484	 * The call, however, might be queued on afs_async_calls and we need to
485	 * make sure we don't get any more notifications that might requeue it.
486	 */
487	if (call->rxcall) {
488		rxrpc_kernel_end_call(call->net->socket, call->rxcall);
489		call->rxcall = NULL;
490	}
491	if (call->async) {
492		if (cancel_work_sync(&call->async_work))
493			afs_put_call(call);
494		afs_set_call_complete(call, ret, 0);
495	}
496
497	ac->error = ret;
498	call->state = AFS_CALL_COMPLETE;
499	_leave(" = %d", ret);
500}
501
502/*
503 * deliver messages to a call
504 */
505static void afs_deliver_to_call(struct afs_call *call)
506{
507	enum afs_call_state state;
508	u32 abort_code, remote_abort = 0;
509	int ret;
510
511	_enter("%s", call->type->name);
512
513	while (state = READ_ONCE(call->state),
514	       state == AFS_CALL_CL_AWAIT_REPLY ||
515	       state == AFS_CALL_SV_AWAIT_OP_ID ||
516	       state == AFS_CALL_SV_AWAIT_REQUEST ||
517	       state == AFS_CALL_SV_AWAIT_ACK
518	       ) {
519		if (state == AFS_CALL_SV_AWAIT_ACK) {
520			iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
521			ret = rxrpc_kernel_recv_data(call->net->socket,
522						     call->rxcall, &call->def_iter,
523						     false, &remote_abort,
524						     &call->service_id);
525			trace_afs_receive_data(call, &call->def_iter, false, ret);
526
527			if (ret == -EINPROGRESS || ret == -EAGAIN)
528				return;
529			if (ret < 0 || ret == 1) {
530				if (ret == 1)
531					ret = 0;
532				goto call_complete;
533			}
534			return;
535		}
536
537		ret = call->type->deliver(call);
538		state = READ_ONCE(call->state);
539		if (ret == 0 && call->unmarshalling_error)
540			ret = -EBADMSG;
541		switch (ret) {
542		case 0:
543			afs_queue_call_work(call);
544			if (state == AFS_CALL_CL_PROC_REPLY) {
545				if (call->op)
546					set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
547						&call->op->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			fallthrough;
567		case -ENODATA:
568		case -EBADMSG:
569		case -EMSGSIZE:
570		case -ENOMEM:
571		case -EFAULT:
572			abort_code = RXGEN_CC_UNMARSHAL;
573			if (state != AFS_CALL_CL_AWAIT_REPLY)
574				abort_code = RXGEN_SS_UNMARSHAL;
575			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
576						abort_code, ret, "KUM");
577			goto local_abort;
578		default:
579			abort_code = RX_CALL_DEAD;
580			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
581						abort_code, ret, "KER");
582			goto local_abort;
583		}
584	}
585
586done:
587	if (call->type->done)
588		call->type->done(call);
589out:
590	_leave("");
591	return;
592
593local_abort:
594	abort_code = 0;
595call_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 */
604long afs_wait_for_call_to_complete(struct afs_call *call,
605				   struct afs_addr_cursor *ac)
606{
607	long ret;
608	bool rxrpc_complete = false;
609
610	DECLARE_WAITQUEUE(myself, current);
611
612	_enter("");
613
614	ret = call->error;
615	if (ret < 0)
616		goto out;
617
618	add_wait_queue(&call->waitq, &myself);
619	for (;;) {
620		set_current_state(TASK_UNINTERRUPTIBLE);
621
622		/* deliver any messages that are in the queue */
623		if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
624		    call->need_attention) {
625			call->need_attention = false;
626			__set_current_state(TASK_RUNNING);
627			afs_deliver_to_call(call);
628			continue;
629		}
630
631		if (afs_check_call_state(call, AFS_CALL_COMPLETE))
632			break;
633
634		if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
635			/* rxrpc terminated the call. */
636			rxrpc_complete = true;
637			break;
638		}
639
640		schedule();
641	}
642
643	remove_wait_queue(&call->waitq, &myself);
644	__set_current_state(TASK_RUNNING);
645
646	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
647		if (rxrpc_complete) {
648			afs_set_call_complete(call, call->error, call->abort_code);
649		} else {
650			/* Kill off the call if it's still live. */
651			_debug("call interrupted");
652			if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
653						    RX_USER_ABORT, -EINTR, "KWI"))
654				afs_set_call_complete(call, -EINTR, 0);
655		}
656	}
657
658	spin_lock_bh(&call->state_lock);
659	ac->abort_code = call->abort_code;
660	ac->error = call->error;
661	spin_unlock_bh(&call->state_lock);
662
663	ret = ac->error;
664	switch (ret) {
665	case 0:
666		ret = call->ret0;
667		call->ret0 = 0;
668
669		fallthrough;
670	case -ECONNABORTED:
671		ac->responded = true;
672		break;
673	}
674
675out:
676	_debug("call complete");
677	afs_put_call(call);
678	_leave(" = %p", (void *)ret);
679	return ret;
680}
681
682/*
683 * wake up a waiting call
684 */
685static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
686				    unsigned long call_user_ID)
687{
688	struct afs_call *call = (struct afs_call *)call_user_ID;
689
690	call->need_attention = true;
691	wake_up(&call->waitq);
692}
693
694/*
695 * wake up an asynchronous call
696 */
697static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
698				   unsigned long call_user_ID)
699{
700	struct afs_call *call = (struct afs_call *)call_user_ID;
701	int u;
702
703	trace_afs_notify_call(rxcall, call);
704	call->need_attention = true;
705
706	u = atomic_fetch_add_unless(&call->usage, 1, 0);
707	if (u != 0) {
708		trace_afs_call(call, afs_call_trace_wake, u + 1,
709			       atomic_read(&call->net->nr_outstanding_calls),
710			       __builtin_return_address(0));
711
712		if (!queue_work(afs_async_calls, &call->async_work))
713			afs_put_call(call);
714	}
715}
716
717/*
718 * Perform I/O processing on an asynchronous call.  The work item carries a ref
719 * to the call struct that we either need to release or to pass on.
720 */
721static void afs_process_async_call(struct work_struct *work)
722{
723	struct afs_call *call = container_of(work, struct afs_call, async_work);
724
725	_enter("");
726
727	if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
728		call->need_attention = false;
729		afs_deliver_to_call(call);
730	}
731
732	afs_put_call(call);
733	_leave("");
734}
735
736static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
737{
738	struct afs_call *call = (struct afs_call *)user_call_ID;
739
740	call->rxcall = rxcall;
741}
742
743/*
744 * Charge the incoming call preallocation.
745 */
746void afs_charge_preallocation(struct work_struct *work)
747{
748	struct afs_net *net =
749		container_of(work, struct afs_net, charge_preallocation_work);
750	struct afs_call *call = net->spare_incoming_call;
751
752	for (;;) {
753		if (!call) {
754			call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
755			if (!call)
756				break;
757
758			call->drop_ref = true;
759			call->async = true;
760			call->state = AFS_CALL_SV_AWAIT_OP_ID;
761			init_waitqueue_head(&call->waitq);
762			afs_extract_to_tmp(call);
763		}
764
765		if (rxrpc_kernel_charge_accept(net->socket,
766					       afs_wake_up_async_call,
767					       afs_rx_attach,
768					       (unsigned long)call,
769					       GFP_KERNEL,
770					       call->debug_id) < 0)
771			break;
772		call = NULL;
773	}
774	net->spare_incoming_call = call;
775}
776
777/*
778 * Discard a preallocated call when a socket is shut down.
779 */
780static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
781				    unsigned long user_call_ID)
782{
783	struct afs_call *call = (struct afs_call *)user_call_ID;
784
785	call->rxcall = NULL;
786	afs_put_call(call);
787}
788
789/*
790 * Notification of an incoming call.
791 */
792static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
793			    unsigned long user_call_ID)
794{
795	struct afs_net *net = afs_sock2net(sk);
796
797	queue_work(afs_wq, &net->charge_preallocation_work);
798}
799
800/*
801 * Grab the operation ID from an incoming cache manager call.  The socket
802 * buffer is discarded on error or if we don't yet have sufficient data.
803 */
804static int afs_deliver_cm_op_id(struct afs_call *call)
805{
806	int ret;
807
808	_enter("{%zu}", iov_iter_count(call->iter));
809
810	/* the operation ID forms the first four bytes of the request data */
811	ret = afs_extract_data(call, true);
812	if (ret < 0)
813		return ret;
814
815	call->operation_ID = ntohl(call->tmp);
816	afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
817
818	/* ask the cache manager to route the call (it'll change the call type
819	 * if successful) */
820	if (!afs_cm_incoming_call(call))
821		return -ENOTSUPP;
822
823	trace_afs_cb_call(call);
824
825	/* pass responsibility for the remainer of this message off to the
826	 * cache manager op */
827	return call->type->deliver(call);
828}
829
830/*
831 * Advance the AFS call state when an RxRPC service call ends the transmit
832 * phase.
833 */
834static void afs_notify_end_reply_tx(struct sock *sock,
835				    struct rxrpc_call *rxcall,
836				    unsigned long call_user_ID)
837{
838	struct afs_call *call = (struct afs_call *)call_user_ID;
839
840	afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
841}
842
843/*
844 * send an empty reply
845 */
846void afs_send_empty_reply(struct afs_call *call)
847{
848	struct afs_net *net = call->net;
849	struct msghdr msg;
850
851	_enter("");
852
853	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
854
855	msg.msg_name		= NULL;
856	msg.msg_namelen		= 0;
857	iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
858	msg.msg_control		= NULL;
859	msg.msg_controllen	= 0;
860	msg.msg_flags		= 0;
861
862	switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
863				       afs_notify_end_reply_tx)) {
864	case 0:
865		_leave(" [replied]");
866		return;
867
868	case -ENOMEM:
869		_debug("oom");
870		rxrpc_kernel_abort_call(net->socket, call->rxcall,
871					RXGEN_SS_MARSHAL, -ENOMEM, "KOO");
872		fallthrough;
873	default:
874		_leave(" [error]");
875		return;
876	}
877}
878
879/*
880 * send a simple reply
881 */
882void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
883{
884	struct afs_net *net = call->net;
885	struct msghdr msg;
886	struct kvec iov[1];
887	int n;
888
889	_enter("");
890
891	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
892
893	iov[0].iov_base		= (void *) buf;
894	iov[0].iov_len		= len;
895	msg.msg_name		= NULL;
896	msg.msg_namelen		= 0;
897	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
898	msg.msg_control		= NULL;
899	msg.msg_controllen	= 0;
900	msg.msg_flags		= 0;
901
902	n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
903				   afs_notify_end_reply_tx);
904	if (n >= 0) {
905		/* Success */
906		_leave(" [replied]");
907		return;
908	}
909
910	if (n == -ENOMEM) {
911		_debug("oom");
912		rxrpc_kernel_abort_call(net->socket, call->rxcall,
913					RXGEN_SS_MARSHAL, -ENOMEM, "KOO");
914	}
915	_leave(" [error]");
916}
917
918/*
919 * Extract a piece of data from the received data socket buffers.
920 */
921int afs_extract_data(struct afs_call *call, bool want_more)
922{
923	struct afs_net *net = call->net;
924	struct iov_iter *iter = call->iter;
925	enum afs_call_state state;
926	u32 remote_abort = 0;
927	int ret;
928
929	_enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
930
931	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
932				     want_more, &remote_abort,
933				     &call->service_id);
934	if (ret == 0 || ret == -EAGAIN)
935		return ret;
936
937	state = READ_ONCE(call->state);
938	if (ret == 1) {
939		switch (state) {
940		case AFS_CALL_CL_AWAIT_REPLY:
941			afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
942			break;
943		case AFS_CALL_SV_AWAIT_REQUEST:
944			afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
945			break;
946		case AFS_CALL_COMPLETE:
947			kdebug("prem complete %d", call->error);
948			return afs_io_error(call, afs_io_error_extract);
949		default:
950			break;
951		}
952		return 0;
953	}
954
955	afs_set_call_complete(call, ret, remote_abort);
956	return ret;
957}
958
959/*
960 * Log protocol error production.
961 */
962noinline int afs_protocol_error(struct afs_call *call,
963				enum afs_eproto_cause cause)
964{
965	trace_afs_protocol_error(call, cause);
966	if (call)
967		call->unmarshalling_error = true;
968	return -EBADMSG;
969}
970