summaryrefslogtreecommitdiff
path: root/drivers/nvme/target/configfs.c
blob: e6b2d2af81b607d5f18ed9579674e08cd51211fe (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
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
/*
 * Configfs interface for the NVMe target.
 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/ctype.h>

#include "nvmet.h"

static const struct config_item_type nvmet_host_type;
static const struct config_item_type nvmet_subsys_type;

/*
 * nvmet_port Generic ConfigFS definitions.
 * Used in any place in the ConfigFS tree that refers to an address.
 */
static ssize_t nvmet_addr_adrfam_show(struct config_item *item,
		char *page)
{
	switch (to_nvmet_port(item)->disc_addr.adrfam) {
	case NVMF_ADDR_FAMILY_IP4:
		return sprintf(page, "ipv4\n");
	case NVMF_ADDR_FAMILY_IP6:
		return sprintf(page, "ipv6\n");
	case NVMF_ADDR_FAMILY_IB:
		return sprintf(page, "ib\n");
	case NVMF_ADDR_FAMILY_FC:
		return sprintf(page, "fc\n");
	default:
		return sprintf(page, "\n");
	}
}

static ssize_t nvmet_addr_adrfam_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_port *port = to_nvmet_port(item);

	if (port->enabled) {
		pr_err("Cannot modify address while enabled\n");
		pr_err("Disable the address before modifying\n");
		return -EACCES;
	}

	if (sysfs_streq(page, "ipv4")) {
		port->disc_addr.adrfam = NVMF_ADDR_FAMILY_IP4;
	} else if (sysfs_streq(page, "ipv6")) {
		port->disc_addr.adrfam = NVMF_ADDR_FAMILY_IP6;
	} else if (sysfs_streq(page, "ib")) {
		port->disc_addr.adrfam = NVMF_ADDR_FAMILY_IB;
	} else if (sysfs_streq(page, "fc")) {
		port->disc_addr.adrfam = NVMF_ADDR_FAMILY_FC;
	} else {
		pr_err("Invalid value '%s' for adrfam\n", page);
		return -EINVAL;
	}

	return count;
}

CONFIGFS_ATTR(nvmet_, addr_adrfam);

static ssize_t nvmet_addr_portid_show(struct config_item *item,
		char *page)
{
	struct nvmet_port *port = to_nvmet_port(item);

	return snprintf(page, PAGE_SIZE, "%d\n",
			le16_to_cpu(port->disc_addr.portid));
}

static ssize_t nvmet_addr_portid_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_port *port = to_nvmet_port(item);
	u16 portid = 0;

	if (kstrtou16(page, 0, &portid)) {
		pr_err("Invalid value '%s' for portid\n", page);
		return -EINVAL;
	}

	if (port->enabled) {
		pr_err("Cannot modify address while enabled\n");
		pr_err("Disable the address before modifying\n");
		return -EACCES;
	}
	port->disc_addr.portid = cpu_to_le16(portid);
	return count;
}

CONFIGFS_ATTR(nvmet_, addr_portid);

static ssize_t nvmet_addr_traddr_show(struct config_item *item,
		char *page)
{
	struct nvmet_port *port = to_nvmet_port(item);

	return snprintf(page, PAGE_SIZE, "%s\n",
			port->disc_addr.traddr);
}

static ssize_t nvmet_addr_traddr_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_port *port = to_nvmet_port(item);

	if (count > NVMF_TRADDR_SIZE) {
		pr_err("Invalid value '%s' for traddr\n", page);
		return -EINVAL;
	}

	if (port->enabled) {
		pr_err("Cannot modify address while enabled\n");
		pr_err("Disable the address before modifying\n");
		return -EACCES;
	}
	return snprintf(port->disc_addr.traddr,
			sizeof(port->disc_addr.traddr), "%s", page);
}

CONFIGFS_ATTR(nvmet_, addr_traddr);

static ssize_t nvmet_addr_treq_show(struct config_item *item,
		char *page)
{
	switch (to_nvmet_port(item)->disc_addr.treq) {
	case NVMF_TREQ_NOT_SPECIFIED:
		return sprintf(page, "not specified\n");
	case NVMF_TREQ_REQUIRED:
		return sprintf(page, "required\n");
	case NVMF_TREQ_NOT_REQUIRED:
		return sprintf(page, "not required\n");
	default:
		return sprintf(page, "\n");
	}
}

static ssize_t nvmet_addr_treq_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_port *port = to_nvmet_port(item);

	if (port->enabled) {
		pr_err("Cannot modify address while enabled\n");
		pr_err("Disable the address before modifying\n");
		return -EACCES;
	}

	if (sysfs_streq(page, "not specified")) {
		port->disc_addr.treq = NVMF_TREQ_NOT_SPECIFIED;
	} else if (sysfs_streq(page, "required")) {
		port->disc_addr.treq = NVMF_TREQ_REQUIRED;
	} else if (sysfs_streq(page, "not required")) {
		port->disc_addr.treq = NVMF_TREQ_NOT_REQUIRED;
	} else {
		pr_err("Invalid value '%s' for treq\n", page);
		return -EINVAL;
	}

	return count;
}

CONFIGFS_ATTR(nvmet_, addr_treq);

static ssize_t nvmet_addr_trsvcid_show(struct config_item *item,
		char *page)
{
	struct nvmet_port *port = to_nvmet_port(item);

	return snprintf(page, PAGE_SIZE, "%s\n",
			port->disc_addr.trsvcid);
}

static ssize_t nvmet_addr_trsvcid_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_port *port = to_nvmet_port(item);

	if (count > NVMF_TRSVCID_SIZE) {
		pr_err("Invalid value '%s' for trsvcid\n", page);
		return -EINVAL;
	}
	if (port->enabled) {
		pr_err("Cannot modify address while enabled\n");
		pr_err("Disable the address before modifying\n");
		return -EACCES;
	}
	return snprintf(port->disc_addr.trsvcid,
			sizeof(port->disc_addr.trsvcid), "%s", page);
}

CONFIGFS_ATTR(nvmet_, addr_trsvcid);

static ssize_t nvmet_addr_trtype_show(struct config_item *item,
		char *page)
{
	switch (to_nvmet_port(item)->disc_addr.trtype) {
	case NVMF_TRTYPE_RDMA:
		return sprintf(page, "rdma\n");
	case NVMF_TRTYPE_LOOP:
		return sprintf(page, "loop\n");
	case NVMF_TRTYPE_FC:
		return sprintf(page, "fc\n");
	default:
		return sprintf(page, "\n");
	}
}

static void nvmet_port_init_tsas_rdma(struct nvmet_port *port)
{
	port->disc_addr.trtype = NVMF_TRTYPE_RDMA;
	memset(&port->disc_addr.tsas.rdma, 0, NVMF_TSAS_SIZE);
	port->disc_addr.tsas.rdma.qptype = NVMF_RDMA_QPTYPE_CONNECTED;
	port->disc_addr.tsas.rdma.prtype = NVMF_RDMA_PRTYPE_NOT_SPECIFIED;
	port->disc_addr.tsas.rdma.cms = NVMF_RDMA_CMS_RDMA_CM;
}

static void nvmet_port_init_tsas_loop(struct nvmet_port *port)
{
	port->disc_addr.trtype = NVMF_TRTYPE_LOOP;
	memset(&port->disc_addr.tsas, 0, NVMF_TSAS_SIZE);
}

static void nvmet_port_init_tsas_fc(struct nvmet_port *port)
{
	port->disc_addr.trtype = NVMF_TRTYPE_FC;
	memset(&port->disc_addr.tsas, 0, NVMF_TSAS_SIZE);
}

static ssize_t nvmet_addr_trtype_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_port *port = to_nvmet_port(item);

	if (port->enabled) {
		pr_err("Cannot modify address while enabled\n");
		pr_err("Disable the address before modifying\n");
		return -EACCES;
	}

	if (sysfs_streq(page, "rdma")) {
		nvmet_port_init_tsas_rdma(port);
	} else if (sysfs_streq(page, "loop")) {
		nvmet_port_init_tsas_loop(port);
	} else if (sysfs_streq(page, "fc")) {
		nvmet_port_init_tsas_fc(port);
	} else {
		pr_err("Invalid value '%s' for trtype\n", page);
		return -EINVAL;
	}

	return count;
}

CONFIGFS_ATTR(nvmet_, addr_trtype);

/*
 * Namespace structures & file operation functions below
 */
static ssize_t nvmet_ns_device_path_show(struct config_item *item, char *page)
{
	return sprintf(page, "%s\n", to_nvmet_ns(item)->device_path);
}

static ssize_t nvmet_ns_device_path_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_ns *ns = to_nvmet_ns(item);
	struct nvmet_subsys *subsys = ns->subsys;
	int ret;

	mutex_lock(&subsys->lock);
	ret = -EBUSY;
	if (ns->enabled)
		goto out_unlock;

	kfree(ns->device_path);

	ret = -ENOMEM;
	ns->device_path = kstrdup(page, GFP_KERNEL);
	if (!ns->device_path)
		goto out_unlock;

	mutex_unlock(&subsys->lock);
	return count;

out_unlock:
	mutex_unlock(&subsys->lock);
	return ret;
}

CONFIGFS_ATTR(nvmet_ns_, device_path);

static ssize_t nvmet_ns_device_uuid_show(struct config_item *item, char *page)
{
	return sprintf(page, "%pUb\n", &to_nvmet_ns(item)->uuid);
}

static ssize_t nvmet_ns_device_uuid_store(struct config_item *item,
					  const char *page, size_t count)
{
	struct nvmet_ns *ns = to_nvmet_ns(item);
	struct nvmet_subsys *subsys = ns->subsys;
	int ret = 0;


	mutex_lock(&subsys->lock);
	if (ns->enabled) {
		ret = -EBUSY;
		goto out_unlock;
	}


	if (uuid_parse(page, &ns->uuid))
		ret = -EINVAL;

out_unlock:
	mutex_unlock(&subsys->lock);
	return ret ? ret : count;
}

static ssize_t nvmet_ns_device_nguid_show(struct config_item *item, char *page)
{
	return sprintf(page, "%pUb\n", &to_nvmet_ns(item)->nguid);
}

CONFIGFS_ATTR(nvmet_ns_, device_uuid);

static ssize_t nvmet_ns_device_nguid_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_ns *ns = to_nvmet_ns(item);
	struct nvmet_subsys *subsys = ns->subsys;
	u8 nguid[16];
	const char *p = page;
	int i;
	int ret = 0;

	mutex_lock(&subsys->lock);
	if (ns->enabled) {
		ret = -EBUSY;
		goto out_unlock;
	}

	for (i = 0; i < 16; i++) {
		if (p + 2 > page + count) {
			ret = -EINVAL;
			goto out_unlock;
		}
		if (!isxdigit(p[0]) || !isxdigit(p[1])) {
			ret = -EINVAL;
			goto out_unlock;
		}

		nguid[i] = (hex_to_bin(p[0]) << 4) | hex_to_bin(p[1]);
		p += 2;

		if (*p == '-' || *p == ':')
			p++;
	}

	memcpy(&ns->nguid, nguid, sizeof(nguid));
out_unlock:
	mutex_unlock(&subsys->lock);
	return ret ? ret : count;
}

CONFIGFS_ATTR(nvmet_ns_, device_nguid);

static ssize_t nvmet_ns_enable_show(struct config_item *item, char *page)
{
	return sprintf(page, "%d\n", to_nvmet_ns(item)->enabled);
}

static ssize_t nvmet_ns_enable_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_ns *ns = to_nvmet_ns(item);
	bool enable;
	int ret = 0;

	if (strtobool(page, &enable))
		return -EINVAL;

	if (enable)
		ret = nvmet_ns_enable(ns);
	else
		nvmet_ns_disable(ns);

	return ret ? ret : count;
}

CONFIGFS_ATTR(nvmet_ns_, enable);

static struct configfs_attribute *nvmet_ns_attrs[] = {
	&nvmet_ns_attr_device_path,
	&nvmet_ns_attr_device_nguid,
	&nvmet_ns_attr_device_uuid,
	&nvmet_ns_attr_enable,
	NULL,
};

static void nvmet_ns_release(struct config_item *item)
{
	struct nvmet_ns *ns = to_nvmet_ns(item);

	nvmet_ns_free(ns);
}

static struct configfs_item_operations nvmet_ns_item_ops = {
	.release		= nvmet_ns_release,
};

static const struct config_item_type nvmet_ns_type = {
	.ct_item_ops		= &nvmet_ns_item_ops,
	.ct_attrs		= nvmet_ns_attrs,
	.ct_owner		= THIS_MODULE,
};

static struct config_group *nvmet_ns_make(struct config_group *group,
		const char *name)
{
	struct nvmet_subsys *subsys = namespaces_to_subsys(&group->cg_item);
	struct nvmet_ns *ns;
	int ret;
	u32 nsid;

	ret = kstrtou32(name, 0, &nsid);
	if (ret)
		goto out;

	ret = -EINVAL;
	if (nsid == 0 || nsid == NVME_NSID_ALL)
		goto out;

	ret = -ENOMEM;
	ns = nvmet_ns_alloc(subsys, nsid);
	if (!ns)
		goto out;
	config_group_init_type_name(&ns->group, name, &nvmet_ns_type);

	pr_info("adding nsid %d to subsystem %s\n", nsid, subsys->subsysnqn);

	return &ns->group;
out:
	return ERR_PTR(ret);
}

static struct configfs_group_operations nvmet_namespaces_group_ops = {
	.make_group		= nvmet_ns_make,
};

static const struct config_item_type nvmet_namespaces_type = {
	.ct_group_ops		= &nvmet_namespaces_group_ops,
	.ct_owner		= THIS_MODULE,
};

static int nvmet_port_subsys_allow_link(struct config_item *parent,
		struct config_item *target)
{
	struct nvmet_port *port = to_nvmet_port(parent->ci_parent);
	struct nvmet_subsys *subsys;
	struct nvmet_subsys_link *link, *p;
	int ret;

	if (target->ci_type != &nvmet_subsys_type) {
		pr_err("can only link subsystems into the subsystems dir.!\n");
		return -EINVAL;
	}
	subsys = to_subsys(target);
	link = kmalloc(sizeof(*link), GFP_KERNEL);
	if (!link)
		return -ENOMEM;
	link->subsys = subsys;

	down_write(&nvmet_config_sem);
	ret = -EEXIST;
	list_for_each_entry(p, &port->subsystems, entry) {
		if (p->subsys == subsys)
			goto out_free_link;
	}

	if (list_empty(&port->subsystems)) {
		ret = nvmet_enable_port(port);
		if (ret)
			goto out_free_link;
	}

	list_add_tail(&link->entry, &port->subsystems);
	nvmet_genctr++;
	up_write(&nvmet_config_sem);
	return 0;

out_free_link:
	up_write(&nvmet_config_sem);
	kfree(link);
	return ret;
}

static void nvmet_port_subsys_drop_link(struct config_item *parent,
		struct config_item *target)
{
	struct nvmet_port *port = to_nvmet_port(parent->ci_parent);
	struct nvmet_subsys *subsys = to_subsys(target);
	struct nvmet_subsys_link *p;

	down_write(&nvmet_config_sem);
	list_for_each_entry(p, &port->subsystems, entry) {
		if (p->subsys == subsys)
			goto found;
	}
	up_write(&nvmet_config_sem);
	return;

found:
	list_del(&p->entry);
	nvmet_genctr++;
	if (list_empty(&port->subsystems))
		nvmet_disable_port(port);
	up_write(&nvmet_config_sem);
	kfree(p);
}

static struct configfs_item_operations nvmet_port_subsys_item_ops = {
	.allow_link		= nvmet_port_subsys_allow_link,
	.drop_link		= nvmet_port_subsys_drop_link,
};

static const struct config_item_type nvmet_port_subsys_type = {
	.ct_item_ops		= &nvmet_port_subsys_item_ops,
	.ct_owner		= THIS_MODULE,
};

static int nvmet_allowed_hosts_allow_link(struct config_item *parent,
		struct config_item *target)
{
	struct nvmet_subsys *subsys = to_subsys(parent->ci_parent);
	struct nvmet_host *host;
	struct nvmet_host_link *link, *p;
	int ret;

	if (target->ci_type != &nvmet_host_type) {
		pr_err("can only link hosts into the allowed_hosts directory!\n");
		return -EINVAL;
	}

	host = to_host(target);
	link = kmalloc(sizeof(*link), GFP_KERNEL);
	if (!link)
		return -ENOMEM;
	link->host = host;

	down_write(&nvmet_config_sem);
	ret = -EINVAL;
	if (subsys->allow_any_host) {
		pr_err("can't add hosts when allow_any_host is set!\n");
		goto out_free_link;
	}

	ret = -EEXIST;
	list_for_each_entry(p, &subsys->hosts, entry) {
		if (!strcmp(nvmet_host_name(p->host), nvmet_host_name(host)))
			goto out_free_link;
	}
	list_add_tail(&link->entry, &subsys->hosts);
	nvmet_genctr++;
	up_write(&nvmet_config_sem);
	return 0;
out_free_link:
	up_write(&nvmet_config_sem);
	kfree(link);
	return ret;
}

static void nvmet_allowed_hosts_drop_link(struct config_item *parent,
		struct config_item *target)
{
	struct nvmet_subsys *subsys = to_subsys(parent->ci_parent);
	struct nvmet_host *host = to_host(target);
	struct nvmet_host_link *p;

	down_write(&nvmet_config_sem);
	list_for_each_entry(p, &subsys->hosts, entry) {
		if (!strcmp(nvmet_host_name(p->host), nvmet_host_name(host)))
			goto found;
	}
	up_write(&nvmet_config_sem);
	return;

found:
	list_del(&p->entry);
	nvmet_genctr++;
	up_write(&nvmet_config_sem);
	kfree(p);
}

static struct configfs_item_operations nvmet_allowed_hosts_item_ops = {
	.allow_link		= nvmet_allowed_hosts_allow_link,
	.drop_link		= nvmet_allowed_hosts_drop_link,
};

static const struct config_item_type nvmet_allowed_hosts_type = {
	.ct_item_ops		= &nvmet_allowed_hosts_item_ops,
	.ct_owner		= THIS_MODULE,
};

static ssize_t nvmet_subsys_attr_allow_any_host_show(struct config_item *item,
		char *page)
{
	return snprintf(page, PAGE_SIZE, "%d\n",
		to_subsys(item)->allow_any_host);
}

static ssize_t nvmet_subsys_attr_allow_any_host_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_subsys *subsys = to_subsys(item);
	bool allow_any_host;
	int ret = 0;

	if (strtobool(page, &allow_any_host))
		return -EINVAL;

	down_write(&nvmet_config_sem);
	if (allow_any_host && !list_empty(&subsys->hosts)) {
		pr_err("Can't set allow_any_host when explicit hosts are set!\n");
		ret = -EINVAL;
		goto out_unlock;
	}

	subsys->allow_any_host = allow_any_host;
out_unlock:
	up_write(&nvmet_config_sem);
	return ret ? ret : count;
}

CONFIGFS_ATTR(nvmet_subsys_, attr_allow_any_host);

static ssize_t nvmet_subsys_attr_version_show(struct config_item *item,
					      char *page)
{
	struct nvmet_subsys *subsys = to_subsys(item);

	if (NVME_TERTIARY(subsys->ver))
		return snprintf(page, PAGE_SIZE, "%d.%d.%d\n",
				(int)NVME_MAJOR(subsys->ver),
				(int)NVME_MINOR(subsys->ver),
				(int)NVME_TERTIARY(subsys->ver));
	else
		return snprintf(page, PAGE_SIZE, "%d.%d\n",
				(int)NVME_MAJOR(subsys->ver),
				(int)NVME_MINOR(subsys->ver));
}

static ssize_t nvmet_subsys_attr_version_store(struct config_item *item,
					       const char *page, size_t count)
{
	struct nvmet_subsys *subsys = to_subsys(item);
	int major, minor, tertiary = 0;
	int ret;


	ret = sscanf(page, "%d.%d.%d\n", &major, &minor, &tertiary);
	if (ret != 2 && ret != 3)
		return -EINVAL;

	down_write(&nvmet_config_sem);
	subsys->ver = NVME_VS(major, minor, tertiary);
	up_write(&nvmet_config_sem);

	return count;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_version);

static ssize_t nvmet_subsys_attr_serial_show(struct config_item *item,
					     char *page)
{
	struct nvmet_subsys *subsys = to_subsys(item);

	return snprintf(page, PAGE_SIZE, "%llx\n", subsys->serial);
}

static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,
					      const char *page, size_t count)
{
	struct nvmet_subsys *subsys = to_subsys(item);

	down_write(&nvmet_config_sem);
	sscanf(page, "%llx\n", &subsys->serial);
	up_write(&nvmet_config_sem);

	return count;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_serial);

static struct configfs_attribute *nvmet_subsys_attrs[] = {
	&nvmet_subsys_attr_attr_allow_any_host,
	&nvmet_subsys_attr_attr_version,
	&nvmet_subsys_attr_attr_serial,
	NULL,
};

/*
 * Subsystem structures & folder operation functions below
 */
static void nvmet_subsys_release(struct config_item *item)
{
	struct nvmet_subsys *subsys = to_subsys(item);

	nvmet_subsys_del_ctrls(subsys);
	nvmet_subsys_put(subsys);
}

static struct configfs_item_operations nvmet_subsys_item_ops = {
	.release		= nvmet_subsys_release,
};

static const struct config_item_type nvmet_subsys_type = {
	.ct_item_ops		= &nvmet_subsys_item_ops,
	.ct_attrs		= nvmet_subsys_attrs,
	.ct_owner		= THIS_MODULE,
};

static struct config_group *nvmet_subsys_make(struct config_group *group,
		const char *name)
{
	struct nvmet_subsys *subsys;

	if (sysfs_streq(name, NVME_DISC_SUBSYS_NAME)) {
		pr_err("can't create discovery subsystem through configfs\n");
		return ERR_PTR(-EINVAL);
	}

	subsys = nvmet_subsys_alloc(name, NVME_NQN_NVME);
	if (!subsys)
		return ERR_PTR(-ENOMEM);

	config_group_init_type_name(&subsys->group, name, &nvmet_subsys_type);

	config_group_init_type_name(&subsys->namespaces_group,
			"namespaces", &nvmet_namespaces_type);
	configfs_add_default_group(&subsys->namespaces_group, &subsys->group);

	config_group_init_type_name(&subsys->allowed_hosts_group,
			"allowed_hosts", &nvmet_allowed_hosts_type);
	configfs_add_default_group(&subsys->allowed_hosts_group,
			&subsys->group);

	return &subsys->group;
}

static struct configfs_group_operations nvmet_subsystems_group_ops = {
	.make_group		= nvmet_subsys_make,
};

static const struct config_item_type nvmet_subsystems_type = {
	.ct_group_ops		= &nvmet_subsystems_group_ops,
	.ct_owner		= THIS_MODULE,
};

static ssize_t nvmet_referral_enable_show(struct config_item *item,
		char *page)
{
	return snprintf(page, PAGE_SIZE, "%d\n", to_nvmet_port(item)->enabled);
}

static ssize_t nvmet_referral_enable_store(struct config_item *item,
		const char *page, size_t count)
{
	struct nvmet_port *parent = to_nvmet_port(item->ci_parent->ci_parent);
	struct nvmet_port *port = to_nvmet_port(item);
	bool enable;

	if (strtobool(page, &enable))
		goto inval;

	if (enable)
		nvmet_referral_enable(parent, port);
	else
		nvmet_referral_disable(port);

	return count;
inval:
	pr_err("Invalid value '%s' for enable\n", page);
	return -EINVAL;
}

CONFIGFS_ATTR(nvmet_referral_, enable);

/*
 * Discovery Service subsystem definitions
 */
static struct configfs_attribute *nvmet_referral_attrs[] = {
	&nvmet_attr_addr_adrfam,
	&nvmet_attr_addr_portid,
	&nvmet_attr_addr_treq,
	&nvmet_attr_addr_traddr,
	&nvmet_attr_addr_trsvcid,
	&nvmet_attr_addr_trtype,
	&nvmet_referral_attr_enable,
	NULL,
};

static void nvmet_referral_release(struct config_item *item)
{
	struct nvmet_port *port = to_nvmet_port(item);

	nvmet_referral_disable(port);
	kfree(port);
}

static struct configfs_item_operations nvmet_referral_item_ops = {
	.release	= nvmet_referral_release,
};

static const struct config_item_type nvmet_referral_type = {
	.ct_owner	= THIS_MODULE,
	.ct_attrs	= nvmet_referral_attrs,
	.ct_item_ops	= &nvmet_referral_item_ops,
};

static struct config_group *nvmet_referral_make(
		struct config_group *group, const char *name)
{
	struct nvmet_port *port;

	port = kzalloc(sizeof(*port), GFP_KERNEL);
	if (!port)
		return ERR_PTR(-ENOMEM);

	INIT_LIST_HEAD(&port->entry);
	config_group_init_type_name(&port->group, name, &nvmet_referral_type);

	return &port->group;
}

static struct configfs_group_operations nvmet_referral_group_ops = {
	.make_group		= nvmet_referral_make,
};

static const struct config_item_type nvmet_referrals_type = {
	.ct_owner	= THIS_MODULE,
	.ct_group_ops	= &nvmet_referral_group_ops,
};

/*
 * Ports definitions.
 */
static void nvmet_port_release(struct config_item *item)
{
	struct nvmet_port *port = to_nvmet_port(item);

	kfree(port);
}

static struct configfs_attribute *nvmet_port_attrs[] = {
	&nvmet_attr_addr_adrfam,
	&nvmet_attr_addr_treq,
	&nvmet_attr_addr_traddr,
	&nvmet_attr_addr_trsvcid,
	&nvmet_attr_addr_trtype,
	NULL,
};

static struct configfs_item_operations nvmet_port_item_ops = {
	.release		= nvmet_port_release,
};

static const struct config_item_type nvmet_port_type = {
	.ct_attrs		= nvmet_port_attrs,
	.ct_item_ops		= &nvmet_port_item_ops,
	.ct_owner		= THIS_MODULE,
};

static struct config_group *nvmet_ports_make(struct config_group *group,
		const char *name)
{
	struct nvmet_port *port;
	u16 portid;

	if (kstrtou16(name, 0, &portid))
		return ERR_PTR(-EINVAL);

	port = kzalloc(sizeof(*port), GFP_KERNEL);
	if (!port)
		return ERR_PTR(-ENOMEM);

	INIT_LIST_HEAD(&port->entry);
	INIT_LIST_HEAD(&port->subsystems);
	INIT_LIST_HEAD(&port->referrals);

	port->disc_addr.portid = cpu_to_le16(portid);
	config_group_init_type_name(&port->group, name, &nvmet_port_type);

	config_group_init_type_name(&port->subsys_group,
			"subsystems", &nvmet_port_subsys_type);
	configfs_add_default_group(&port->subsys_group, &port->group);

	config_group_init_type_name(&port->referrals_group,
			"referrals", &nvmet_referrals_type);
	configfs_add_default_group(&port->referrals_group, &port->group);

	return &port->group;
}

static struct configfs_group_operations nvmet_ports_group_ops = {
	.make_group		= nvmet_ports_make,
};

static const struct config_item_type nvmet_ports_type = {
	.ct_group_ops		= &nvmet_ports_group_ops,
	.ct_owner		= THIS_MODULE,
};

static struct config_group nvmet_subsystems_group;
static struct config_group nvmet_ports_group;

static void nvmet_host_release(struct config_item *item)
{
	struct nvmet_host *host = to_host(item);

	kfree(host);
}

static struct configfs_item_operations nvmet_host_item_ops = {
	.release		= nvmet_host_release,
};

static const struct config_item_type nvmet_host_type = {
	.ct_item_ops		= &nvmet_host_item_ops,
	.ct_owner		= THIS_MODULE,
};

static struct config_group *nvmet_hosts_make_group(struct config_group *group,
		const char *name)
{
	struct nvmet_host *host;

	host = kzalloc(sizeof(*host), GFP_KERNEL);
	if (!host)
		return ERR_PTR(-ENOMEM);

	config_group_init_type_name(&host->group, name, &nvmet_host_type);

	return &host->group;
}

static struct configfs_group_operations nvmet_hosts_group_ops = {
	.make_group		= nvmet_hosts_make_group,
};

static const struct config_item_type nvmet_hosts_type = {
	.ct_group_ops		= &nvmet_hosts_group_ops,
	.ct_owner		= THIS_MODULE,
};

static struct config_group nvmet_hosts_group;

static const struct config_item_type nvmet_root_type = {
	.ct_owner		= THIS_MODULE,
};

static struct configfs_subsystem nvmet_configfs_subsystem = {
	.su_group = {
		.cg_item = {
			.ci_namebuf	= "nvmet",
			.ci_type	= &nvmet_root_type,
		},
	},
};

int __init nvmet_init_configfs(void)
{
	int ret;

	config_group_init(&nvmet_configfs_subsystem.su_group);
	mutex_init(&nvmet_configfs_subsystem.su_mutex);

	config_group_init_type_name(&nvmet_subsystems_group,
			"subsystems", &nvmet_subsystems_type);
	configfs_add_default_group(&nvmet_subsystems_group,
			&nvmet_configfs_subsystem.su_group);

	config_group_init_type_name(&nvmet_ports_group,
			"ports", &nvmet_ports_type);
	configfs_add_default_group(&nvmet_ports_group,
			&nvmet_configfs_subsystem.su_group);

	config_group_init_type_name(&nvmet_hosts_group,
			"hosts", &nvmet_hosts_type);
	configfs_add_default_group(&nvmet_hosts_group,
			&nvmet_configfs_subsystem.su_group);

	ret = configfs_register_subsystem(&nvmet_configfs_subsystem);
	if (ret) {
		pr_err("configfs_register_subsystem: %d\n", ret);
		return ret;
	}

	return 0;
}

void __exit nvmet_exit_configfs(void)
{
	configfs_unregister_subsystem(&nvmet_configfs_subsystem);
}