summaryrefslogtreecommitdiff
path: root/fs/afs/vlclient.c
blob: db7e94584e874643d07ecf897bfc00d5c843fd31 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
// SPDX-License-Identifier: GPL-2.0-or-later
/* AFS Volume Location Service client
 *
 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/sched.h>
#include "afs_fs.h"
#include "internal.h"

/*
 * Deliver reply data to a VL.GetEntryByNameU call.
 */
static int afs_deliver_vl_get_entry_by_name_u(struct afs_call *call)
{
	struct afs_uvldbentry__xdr *uvldb;
	struct afs_vldb_entry *entry;
	bool new_only = false;
	u32 tmp, nr_servers, vlflags;
	int i, ret;

	_enter("");

	ret = afs_transfer_reply(call);
	if (ret < 0)
		return ret;

	/* unmarshall the reply once we've received all of it */
	uvldb = call->buffer;
	entry = call->ret_vldb;

	nr_servers = ntohl(uvldb->nServers);
	if (nr_servers > AFS_NMAXNSERVERS)
		nr_servers = AFS_NMAXNSERVERS;

	for (i = 0; i < ARRAY_SIZE(uvldb->name) - 1; i++)
		entry->name[i] = (u8)ntohl(uvldb->name[i]);
	entry->name[i] = 0;
	entry->name_len = strlen(entry->name);

	/* If there is a new replication site that we can use, ignore all the
	 * sites that aren't marked as new.
	 */
	for (i = 0; i < nr_servers; i++) {
		tmp = ntohl(uvldb->serverFlags[i]);
		if (!(tmp & AFS_VLSF_DONTUSE) &&
		    (tmp & AFS_VLSF_NEWREPSITE))
			new_only = true;
	}

	vlflags = ntohl(uvldb->flags);
	for (i = 0; i < nr_servers; i++) {
		struct afs_uuid__xdr *xdr;
		struct afs_uuid *uuid;
		int j;
		int n = entry->nr_servers;

		tmp = ntohl(uvldb->serverFlags[i]);
		if (tmp & AFS_VLSF_DONTUSE ||
		    (new_only && !(tmp & AFS_VLSF_NEWREPSITE)))
			continue;
		if (tmp & AFS_VLSF_RWVOL) {
			entry->fs_mask[n] |= AFS_VOL_VTM_RW;
			if (vlflags & AFS_VLF_BACKEXISTS)
				entry->fs_mask[n] |= AFS_VOL_VTM_BAK;
		}
		if (tmp & AFS_VLSF_ROVOL)
			entry->fs_mask[n] |= AFS_VOL_VTM_RO;
		if (!entry->fs_mask[n])
			continue;

		xdr = &uvldb->serverNumber[i];
		uuid = (struct afs_uuid *)&entry->fs_server[n];
		uuid->time_low			= xdr->time_low;
		uuid->time_mid			= htons(ntohl(xdr->time_mid));
		uuid->time_hi_and_version	= htons(ntohl(xdr->time_hi_and_version));
		uuid->clock_seq_hi_and_reserved	= (u8)ntohl(xdr->clock_seq_hi_and_reserved);
		uuid->clock_seq_low		= (u8)ntohl(xdr->clock_seq_low);
		for (j = 0; j < 6; j++)
			uuid->node[j] = (u8)ntohl(xdr->node[j]);

		entry->addr_version[n] = ntohl(uvldb->serverUnique[i]);
		entry->nr_servers++;
	}

	for (i = 0; i < AFS_MAXTYPES; i++)
		entry->vid[i] = ntohl(uvldb->volumeId[i]);

	if (vlflags & AFS_VLF_RWEXISTS)
		__set_bit(AFS_VLDB_HAS_RW, &entry->flags);
	if (vlflags & AFS_VLF_ROEXISTS)
		__set_bit(AFS_VLDB_HAS_RO, &entry->flags);
	if (vlflags & AFS_VLF_BACKEXISTS)
		__set_bit(AFS_VLDB_HAS_BAK, &entry->flags);

	if (!(vlflags & (AFS_VLF_RWEXISTS | AFS_VLF_ROEXISTS | AFS_VLF_BACKEXISTS))) {
		entry->error = -ENOMEDIUM;
		__set_bit(AFS_VLDB_QUERY_ERROR, &entry->flags);
	}

	__set_bit(AFS_VLDB_QUERY_VALID, &entry->flags);
	_leave(" = 0 [done]");
	return 0;
}

/*
 * VL.GetEntryByNameU operation type.
 */
static const struct afs_call_type afs_RXVLGetEntryByNameU = {
	.name		= "VL.GetEntryByNameU",
	.op		= afs_VL_GetEntryByNameU,
	.deliver	= afs_deliver_vl_get_entry_by_name_u,
	.destructor	= afs_flat_call_destructor,
};

/*
 * Dispatch a get volume entry by name or ID operation (uuid variant).  If the
 * volname is a decimal number then it's a volume ID not a volume name.
 */
struct afs_vldb_entry *afs_vl_get_entry_by_name_u(struct afs_vl_cursor *vc,
						  const char *volname,
						  int volnamesz)
{
	struct afs_vldb_entry *entry;
	struct afs_call *call;
	struct afs_net *net = vc->cell->net;
	size_t reqsz, padsz;
	__be32 *bp;

	_enter("");

	padsz = (4 - (volnamesz & 3)) & 3;
	reqsz = 8 + volnamesz + padsz;

	entry = kzalloc(sizeof(struct afs_vldb_entry), GFP_KERNEL);
	if (!entry)
		return ERR_PTR(-ENOMEM);

	call = afs_alloc_flat_call(net, &afs_RXVLGetEntryByNameU, reqsz,
				   sizeof(struct afs_uvldbentry__xdr));
	if (!call) {
		kfree(entry);
		return ERR_PTR(-ENOMEM);
	}

	call->key = vc->key;
	call->ret_vldb = entry;
	call->max_lifespan = AFS_VL_MAX_LIFESPAN;

	/* Marshall the parameters */
	bp = call->request;
	*bp++ = htonl(VLGETENTRYBYNAMEU);
	*bp++ = htonl(volnamesz);
	memcpy(bp, volname, volnamesz);
	if (padsz > 0)
		memset((void *)bp + volnamesz, 0, padsz);

	trace_afs_make_vl_call(call);
	afs_make_call(&vc->ac, call, GFP_KERNEL);
	afs_wait_for_call_to_complete(call, &vc->ac);
	vc->call_abort_code	= call->abort_code;
	vc->call_error		= call->error;
	vc->call_responded	= call->responded;
	afs_put_call(call);
	if (vc->call_error) {
		kfree(entry);
		return ERR_PTR(vc->call_error);
	}
	return entry;
}

/*
 * Deliver reply data to a VL.GetAddrsU call.
 *
 *	GetAddrsU(IN ListAddrByAttributes *inaddr,
 *		  OUT afsUUID *uuidp1,
 *		  OUT uint32_t *uniquifier,
 *		  OUT uint32_t *nentries,
 *		  OUT bulkaddrs *blkaddrs);
 */
static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
{
	struct afs_addr_list *alist;
	__be32 *bp;
	u32 uniquifier, nentries, count;
	int i, ret;

	_enter("{%u,%zu/%u}",
	       call->unmarshall, iov_iter_count(call->iter), call->count);

	switch (call->unmarshall) {
	case 0:
		afs_extract_to_buf(call,
				   sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32));
		call->unmarshall++;

		/* Extract the returned uuid, uniquifier, nentries and
		 * blkaddrs size */
		fallthrough;
	case 1:
		ret = afs_extract_data(call, true);
		if (ret < 0)
			return ret;

		bp = call->buffer + sizeof(struct afs_uuid__xdr);
		uniquifier	= ntohl(*bp++);
		nentries	= ntohl(*bp++);
		count		= ntohl(*bp);

		nentries = min(nentries, count);
		alist = afs_alloc_addrlist(nentries, FS_SERVICE);
		if (!alist)
			return -ENOMEM;
		alist->version = uniquifier;
		call->ret_alist = alist;
		call->count = count;
		call->count2 = nentries;
		call->unmarshall++;

	more_entries:
		count = min(call->count, 4U);
		afs_extract_to_buf(call, count * sizeof(__be32));

		fallthrough;	/* and extract entries */
	case 2:
		ret = afs_extract_data(call, call->count > 4);
		if (ret < 0)
			return ret;

		alist = call->ret_alist;
		bp = call->buffer;
		count = min(call->count, 4U);
		for (i = 0; i < count; i++) {
			if (alist->nr_addrs < call->count2) {
				ret = afs_merge_fs_addr4(call->net, alist, *bp++, AFS_FS_PORT);
				if (ret < 0)
					return ret;
			}
		}

		call->count -= count;
		if (call->count > 0)
			goto more_entries;
		call->unmarshall++;
		break;
	}

	_leave(" = 0 [done]");
	return 0;
}

/*
 * VL.GetAddrsU operation type.
 */
static const struct afs_call_type afs_RXVLGetAddrsU = {
	.name		= "VL.GetAddrsU",
	.op		= afs_VL_GetAddrsU,
	.deliver	= afs_deliver_vl_get_addrs_u,
	.destructor	= afs_flat_call_destructor,
};

/*
 * Dispatch an operation to get the addresses for a server, where the server is
 * nominated by UUID.
 */
struct afs_addr_list *afs_vl_get_addrs_u(struct afs_vl_cursor *vc,
					 const uuid_t *uuid)
{
	struct afs_ListAddrByAttributes__xdr *r;
	struct afs_addr_list *alist;
	const struct afs_uuid *u = (const struct afs_uuid *)uuid;
	struct afs_call *call;
	struct afs_net *net = vc->cell->net;
	__be32 *bp;
	int i;

	_enter("");

	call = afs_alloc_flat_call(net, &afs_RXVLGetAddrsU,
				   sizeof(__be32) + sizeof(struct afs_ListAddrByAttributes__xdr),
				   sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32));
	if (!call)
		return ERR_PTR(-ENOMEM);

	call->key = vc->key;
	call->ret_alist = NULL;
	call->max_lifespan = AFS_VL_MAX_LIFESPAN;

	/* Marshall the parameters */
	bp = call->request;
	*bp++ = htonl(VLGETADDRSU);
	r = (struct afs_ListAddrByAttributes__xdr *)bp;
	r->Mask		= htonl(AFS_VLADDR_UUID);
	r->ipaddr	= 0;
	r->index	= 0;
	r->spare	= 0;
	r->uuid.time_low			= u->time_low;
	r->uuid.time_mid			= htonl(ntohs(u->time_mid));
	r->uuid.time_hi_and_version		= htonl(ntohs(u->time_hi_and_version));
	r->uuid.clock_seq_hi_and_reserved 	= htonl(u->clock_seq_hi_and_reserved);
	r->uuid.clock_seq_low			= htonl(u->clock_seq_low);
	for (i = 0; i < 6; i++)
		r->uuid.node[i] = htonl(u->node[i]);

	trace_afs_make_vl_call(call);
	afs_make_call(&vc->ac, call, GFP_KERNEL);
	afs_wait_for_call_to_complete(call, &vc->ac);
	vc->call_abort_code	= call->abort_code;
	vc->call_error		= call->error;
	vc->call_responded	= call->responded;
	alist			= call->ret_alist;
	afs_put_call(call);
	if (vc->call_error) {
		afs_put_addrlist(alist);
		return ERR_PTR(vc->call_error);
	}
	return alist;
}

/*
 * Deliver reply data to an VL.GetCapabilities operation.
 */
static int afs_deliver_vl_get_capabilities(struct afs_call *call)
{
	u32 count;
	int ret;

	_enter("{%u,%zu/%u}",
	       call->unmarshall, iov_iter_count(call->iter), call->count);

	switch (call->unmarshall) {
	case 0:
		afs_extract_to_tmp(call);
		call->unmarshall++;

		fallthrough;	/* and extract the capabilities word count */
	case 1:
		ret = afs_extract_data(call, true);
		if (ret < 0)
			return ret;

		count = ntohl(call->tmp);
		call->count = count;
		call->count2 = count;

		call->unmarshall++;
		afs_extract_discard(call, count * sizeof(__be32));

		fallthrough;	/* and extract capabilities words */
	case 2:
		ret = afs_extract_data(call, false);
		if (ret < 0)
			return ret;

		/* TODO: Examine capabilities */

		call->unmarshall++;
		break;
	}

	_leave(" = 0 [done]");
	return 0;
}

static void afs_destroy_vl_get_capabilities(struct afs_call *call)
{
	afs_put_vlserver(call->net, call->vlserver);
	afs_flat_call_destructor(call);
}

/*
 * VL.GetCapabilities operation type
 */
static const struct afs_call_type afs_RXVLGetCapabilities = {
	.name		= "VL.GetCapabilities",
	.op		= afs_VL_GetCapabilities,
	.deliver	= afs_deliver_vl_get_capabilities,
	.done		= afs_vlserver_probe_result,
	.destructor	= afs_destroy_vl_get_capabilities,
};

/*
 * Probe a volume server for the capabilities that it supports.  This can
 * return up to 196 words.
 *
 * We use this to probe for service upgrade to determine what the server at the
 * other end supports.
 */
struct afs_call *afs_vl_get_capabilities(struct afs_net *net,
					 struct afs_addr_cursor *ac,
					 struct key *key,
					 struct afs_vlserver *server,
					 unsigned int server_index)
{
	struct afs_call *call;
	__be32 *bp;

	_enter("");

	call = afs_alloc_flat_call(net, &afs_RXVLGetCapabilities, 1 * 4, 16 * 4);
	if (!call)
		return ERR_PTR(-ENOMEM);

	call->key = key;
	call->vlserver = afs_get_vlserver(server);
	call->server_index = server_index;
	call->upgrade = true;
	call->async = true;
	call->max_lifespan = AFS_PROBE_MAX_LIFESPAN;

	/* marshall the parameters */
	bp = call->request;
	*bp++ = htonl(VLGETCAPABILITIES);

	/* Can't take a ref on server */
	trace_afs_make_vl_call(call);
	afs_make_call(ac, call, GFP_KERNEL);
	return call;
}

/*
 * Deliver reply data to a YFSVL.GetEndpoints call.
 *
 *	GetEndpoints(IN yfsServerAttributes *attr,
 *		     OUT opr_uuid *uuid,
 *		     OUT afs_int32 *uniquifier,
 *		     OUT endpoints *fsEndpoints,
 *		     OUT endpoints *volEndpoints)
 */
static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
{
	struct afs_addr_list *alist;
	__be32 *bp;
	u32 uniquifier, size;
	int ret;

	_enter("{%u,%zu,%u}",
	       call->unmarshall, iov_iter_count(call->iter), call->count2);

	switch (call->unmarshall) {
	case 0:
		afs_extract_to_buf(call, sizeof(uuid_t) + 3 * sizeof(__be32));
		call->unmarshall = 1;

		/* Extract the returned uuid, uniquifier, fsEndpoints count and
		 * either the first fsEndpoint type or the volEndpoints
		 * count if there are no fsEndpoints. */
		fallthrough;
	case 1:
		ret = afs_extract_data(call, true);
		if (ret < 0)
			return ret;

		bp = call->buffer + sizeof(uuid_t);
		uniquifier	= ntohl(*bp++);
		call->count	= ntohl(*bp++);
		call->count2	= ntohl(*bp); /* Type or next count */

		if (call->count > YFS_MAXENDPOINTS)
			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_num);

		alist = afs_alloc_addrlist(call->count, FS_SERVICE);
		if (!alist)
			return -ENOMEM;
		alist->version = uniquifier;
		call->ret_alist = alist;

		if (call->count == 0)
			goto extract_volendpoints;

	next_fsendpoint:
		switch (call->count2) {
		case YFS_ENDPOINT_IPV4:
			size = sizeof(__be32) * (1 + 1 + 1);
			break;
		case YFS_ENDPOINT_IPV6:
			size = sizeof(__be32) * (1 + 4 + 1);
			break;
		default:
			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_type);
		}

		size += sizeof(__be32);
		afs_extract_to_buf(call, size);
		call->unmarshall = 2;

		fallthrough;	/* and extract fsEndpoints[] entries */
	case 2:
		ret = afs_extract_data(call, true);
		if (ret < 0)
			return ret;

		alist = call->ret_alist;
		bp = call->buffer;
		switch (call->count2) {
		case YFS_ENDPOINT_IPV4:
			if (ntohl(bp[0]) != sizeof(__be32) * 2)
				return afs_protocol_error(
					call, afs_eproto_yvl_fsendpt4_len);
			ret = afs_merge_fs_addr4(call->net, alist, bp[1], ntohl(bp[2]));
			if (ret < 0)
				return ret;
			bp += 3;
			break;
		case YFS_ENDPOINT_IPV6:
			if (ntohl(bp[0]) != sizeof(__be32) * 5)
				return afs_protocol_error(
					call, afs_eproto_yvl_fsendpt6_len);
			ret = afs_merge_fs_addr6(call->net, alist, bp + 1, ntohl(bp[5]));
			if (ret < 0)
				return ret;
			bp += 6;
			break;
		default:
			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_type);
		}

		/* Got either the type of the next entry or the count of
		 * volEndpoints if no more fsEndpoints.
		 */
		call->count2 = ntohl(*bp++);

		call->count--;
		if (call->count > 0)
			goto next_fsendpoint;

	extract_volendpoints:
		/* Extract the list of volEndpoints. */
		call->count = call->count2;
		if (!call->count)
			goto end;
		if (call->count > YFS_MAXENDPOINTS)
			return afs_protocol_error(call, afs_eproto_yvl_vlendpt_type);

		afs_extract_to_buf(call, 1 * sizeof(__be32));
		call->unmarshall = 3;

		/* Extract the type of volEndpoints[0].  Normally we would
		 * extract the type of the next endpoint when we extract the
		 * data of the current one, but this is the first...
		 */
		fallthrough;
	case 3:
		ret = afs_extract_data(call, true);
		if (ret < 0)
			return ret;

		bp = call->buffer;

	next_volendpoint:
		call->count2 = ntohl(*bp++);
		switch (call->count2) {
		case YFS_ENDPOINT_IPV4:
			size = sizeof(__be32) * (1 + 1 + 1);
			break;
		case YFS_ENDPOINT_IPV6:
			size = sizeof(__be32) * (1 + 4 + 1);
			break;
		default:
			return afs_protocol_error(call, afs_eproto_yvl_vlendpt_type);
		}

		if (call->count > 1)
			size += sizeof(__be32); /* Get next type too */
		afs_extract_to_buf(call, size);
		call->unmarshall = 4;

		fallthrough;	/* and extract volEndpoints[] entries */
	case 4:
		ret = afs_extract_data(call, true);
		if (ret < 0)
			return ret;

		bp = call->buffer;
		switch (call->count2) {
		case YFS_ENDPOINT_IPV4:
			if (ntohl(bp[0]) != sizeof(__be32) * 2)
				return afs_protocol_error(
					call, afs_eproto_yvl_vlendpt4_len);
			bp += 3;
			break;
		case YFS_ENDPOINT_IPV6:
			if (ntohl(bp[0]) != sizeof(__be32) * 5)
				return afs_protocol_error(
					call, afs_eproto_yvl_vlendpt6_len);
			bp += 6;
			break;
		default:
			return afs_protocol_error(call, afs_eproto_yvl_vlendpt_type);
		}

		/* Got either the type of the next entry or the count of
		 * volEndpoints if no more fsEndpoints.
		 */
		call->count--;
		if (call->count > 0)
			goto next_volendpoint;

	end:
		afs_extract_discard(call, 0);
		call->unmarshall = 5;

		fallthrough;	/* Done */
	case 5:
		ret = afs_extract_data(call, false);
		if (ret < 0)
			return ret;
		call->unmarshall = 6;
		fallthrough;

	case 6:
		break;
	}

	_leave(" = 0 [done]");
	return 0;
}

/*
 * YFSVL.GetEndpoints operation type.
 */
static const struct afs_call_type afs_YFSVLGetEndpoints = {
	.name		= "YFSVL.GetEndpoints",
	.op		= afs_YFSVL_GetEndpoints,
	.deliver	= afs_deliver_yfsvl_get_endpoints,
	.destructor	= afs_flat_call_destructor,
};

/*
 * Dispatch an operation to get the addresses for a server, where the server is
 * nominated by UUID.
 */
struct afs_addr_list *afs_yfsvl_get_endpoints(struct afs_vl_cursor *vc,
					      const uuid_t *uuid)
{
	struct afs_addr_list *alist;
	struct afs_call *call;
	struct afs_net *net = vc->cell->net;
	__be32 *bp;

	_enter("");

	call = afs_alloc_flat_call(net, &afs_YFSVLGetEndpoints,
				   sizeof(__be32) * 2 + sizeof(*uuid),
				   sizeof(struct in6_addr) + sizeof(__be32) * 3);
	if (!call)
		return ERR_PTR(-ENOMEM);

	call->key = vc->key;
	call->ret_alist = NULL;
	call->max_lifespan = AFS_VL_MAX_LIFESPAN;

	/* Marshall the parameters */
	bp = call->request;
	*bp++ = htonl(YVLGETENDPOINTS);
	*bp++ = htonl(YFS_SERVER_UUID);
	memcpy(bp, uuid, sizeof(*uuid)); /* Type opr_uuid */

	trace_afs_make_vl_call(call);
	afs_make_call(&vc->ac, call, GFP_KERNEL);
	afs_wait_for_call_to_complete(call, &vc->ac);
	vc->call_abort_code	= call->abort_code;
	vc->call_error		= call->error;
	vc->call_responded	= call->responded;
	alist			= call->ret_alist;
	afs_put_call(call);
	if (vc->call_error) {
		afs_put_addrlist(alist);
		return ERR_PTR(vc->call_error);
	}
	return alist;
}

/*
 * Deliver reply data to a YFSVL.GetCellName operation.
 */
static int afs_deliver_yfsvl_get_cell_name(struct afs_call *call)
{
	char *cell_name;
	u32 namesz, paddedsz;
	int ret;

	_enter("{%u,%zu/%u}",
	       call->unmarshall, iov_iter_count(call->iter), call->count);

	switch (call->unmarshall) {
	case 0:
		afs_extract_to_tmp(call);
		call->unmarshall++;

		fallthrough;	/* and extract the cell name length */
	case 1:
		ret = afs_extract_data(call, true);
		if (ret < 0)
			return ret;

		namesz = ntohl(call->tmp);
		if (namesz > AFS_MAXCELLNAME)
			return afs_protocol_error(call, afs_eproto_cellname_len);
		paddedsz = (namesz + 3) & ~3;
		call->count = namesz;
		call->count2 = paddedsz - namesz;

		cell_name = kmalloc(namesz + 1, GFP_KERNEL);
		if (!cell_name)
			return -ENOMEM;
		cell_name[namesz] = 0;
		call->ret_str = cell_name;

		afs_extract_begin(call, cell_name, namesz);
		call->unmarshall++;

		fallthrough;	/* and extract cell name */
	case 2:
		ret = afs_extract_data(call, true);
		if (ret < 0)
			return ret;

		afs_extract_discard(call, call->count2);
		call->unmarshall++;

		fallthrough;	/* and extract padding */
	case 3:
		ret = afs_extract_data(call, false);
		if (ret < 0)
			return ret;

		call->unmarshall++;
		break;
	}

	_leave(" = 0 [done]");
	return 0;
}

/*
 * VL.GetCapabilities operation type
 */
static const struct afs_call_type afs_YFSVLGetCellName = {
	.name		= "YFSVL.GetCellName",
	.op		= afs_YFSVL_GetCellName,
	.deliver	= afs_deliver_yfsvl_get_cell_name,
	.destructor	= afs_flat_call_destructor,
};

/*
 * Probe a volume server for the capabilities that it supports.  This can
 * return up to 196 words.
 *
 * We use this to probe for service upgrade to determine what the server at the
 * other end supports.
 */
char *afs_yfsvl_get_cell_name(struct afs_vl_cursor *vc)
{
	struct afs_call *call;
	struct afs_net *net = vc->cell->net;
	__be32 *bp;
	char *cellname;

	_enter("");

	call = afs_alloc_flat_call(net, &afs_YFSVLGetCellName, 1 * 4, 0);
	if (!call)
		return ERR_PTR(-ENOMEM);

	call->key = vc->key;
	call->ret_str = NULL;
	call->max_lifespan = AFS_VL_MAX_LIFESPAN;

	/* marshall the parameters */
	bp = call->request;
	*bp++ = htonl(YVLGETCELLNAME);

	/* Can't take a ref on server */
	trace_afs_make_vl_call(call);
	afs_make_call(&vc->ac, call, GFP_KERNEL);
	afs_wait_for_call_to_complete(call, &vc->ac);
	vc->call_abort_code	= call->abort_code;
	vc->call_error		= call->error;
	vc->call_responded	= call->responded;
	cellname		= call->ret_str;
	afs_put_call(call);
	if (vc->call_error) {
		kfree(cellname);
		return ERR_PTR(vc->call_error);
	}
	return cellname;
}