summaryrefslogtreecommitdiffstats
path: root/drivers/target/target_core_pscsi.c
blob: 69a4c9581e80e50394c29bfb12ed24afc301f748 (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
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
 * Filename:  target_core_pscsi.c
 *
 * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
 *
 * (c) Copyright 2003-2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 ******************************************************************************/

#include <linux/string.h>
#include <linux/parser.h>
#include <linux/timer.h>
#include <linux/blkdev.h>
#include <linux/blk_types.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/cdrom.h>
#include <linux/ratelimit.h>
#include <linux/module.h>
#include <asm/unaligned.h>

#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>

#include <target/target_core_base.h>
#include <target/target_core_backend.h>

#include "target_core_alua.h"
#include "target_core_internal.h"
#include "target_core_pscsi.h"

static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
{
	return container_of(dev, struct pscsi_dev_virt, dev);
}

static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
static enum rq_end_io_ret pscsi_req_done(struct request *, blk_status_t);

/*	pscsi_attach_hba():
 *
 * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
 *	from the passed SCSI Host ID.
 */
static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
{
	struct pscsi_hba_virt *phv;

	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
	if (!phv) {
		pr_err("Unable to allocate struct pscsi_hba_virt\n");
		return -ENOMEM;
	}
	phv->phv_host_id = host_id;
	phv->phv_mode = PHV_VIRTUAL_HOST_ID;

	hba->hba_ptr = phv;

	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
		" Generic Target Core Stack %s\n", hba->hba_id,
		PSCSI_VERSION, TARGET_CORE_VERSION);
	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
	       hba->hba_id);

	return 0;
}

static void pscsi_detach_hba(struct se_hba *hba)
{
	struct pscsi_hba_virt *phv = hba->hba_ptr;
	struct Scsi_Host *scsi_host = phv->phv_lld_host;

	if (scsi_host) {
		scsi_host_put(scsi_host);

		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
			" Generic Target Core\n", hba->hba_id,
			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
			"Unknown");
	} else
		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
			" from Generic Target Core\n", hba->hba_id);

	kfree(phv);
	hba->hba_ptr = NULL;
}

static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
{
	struct pscsi_hba_virt *phv = hba->hba_ptr;
	struct Scsi_Host *sh = phv->phv_lld_host;
	/*
	 * Release the struct Scsi_Host
	 */
	if (!mode_flag) {
		if (!sh)
			return 0;

		phv->phv_lld_host = NULL;
		phv->phv_mode = PHV_VIRTUAL_HOST_ID;

		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
			" %s\n", hba->hba_id, (sh->hostt->name) ?
			(sh->hostt->name) : "Unknown");

		scsi_host_put(sh);
		return 0;
	}
	/*
	 * Otherwise, locate struct Scsi_Host from the original passed
	 * pSCSI Host ID and enable for phba mode
	 */
	sh = scsi_host_lookup(phv->phv_host_id);
	if (!sh) {
		pr_err("pSCSI: Unable to locate SCSI Host for"
			" phv_host_id: %d\n", phv->phv_host_id);
		return -EINVAL;
	}

	phv->phv_lld_host = sh;
	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;

	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");

	return 1;
}

static void pscsi_tape_read_blocksize(struct se_device *dev,
		struct scsi_device *sdev)
{
	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
	int ret;

	buf = kzalloc(12, GFP_KERNEL);
	if (!buf)
		goto out_free;

	memset(cdb, 0, MAX_COMMAND_SIZE);
	cdb[0] = MODE_SENSE;
	cdb[4] = 0x0c; /* 12 bytes */

	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
			HZ, 1, NULL);
	if (ret)
		goto out_free;

	/*
	 * If MODE_SENSE still returns zero, set the default value to 1024.
	 */
	sdev->sector_size = get_unaligned_be24(&buf[9]);
out_free:
	if (!sdev->sector_size)
		sdev->sector_size = 1024;

	kfree(buf);
}

static void
pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
{
	if (sdev->inquiry_len < INQUIRY_LEN)
		return;
	/*
	 * Use sdev->inquiry data from drivers/scsi/scsi_scan.c:scsi_add_lun()
	 */
	BUILD_BUG_ON(sizeof(wwn->vendor) != INQUIRY_VENDOR_LEN + 1);
	snprintf(wwn->vendor, sizeof(wwn->vendor),
		 "%." __stringify(INQUIRY_VENDOR_LEN) "s", sdev->vendor);
	BUILD_BUG_ON(sizeof(wwn->model) != INQUIRY_MODEL_LEN + 1);
	snprintf(wwn->model, sizeof(wwn->model),
		 "%." __stringify(INQUIRY_MODEL_LEN) "s", sdev->model);
	BUILD_BUG_ON(sizeof(wwn->revision) != INQUIRY_REVISION_LEN + 1);
	snprintf(wwn->revision, sizeof(wwn->revision),
		 "%." __stringify(INQUIRY_REVISION_LEN) "s", sdev->rev);
}

static int
pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
{
	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
	int ret;

	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	memset(cdb, 0, MAX_COMMAND_SIZE);
	cdb[0] = INQUIRY;
	cdb[1] = 0x01; /* Query VPD */
	cdb[2] = 0x80; /* Unit Serial Number */
	put_unaligned_be16(INQUIRY_VPD_SERIAL_LEN, &cdb[3]);

	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
	if (ret)
		goto out_free;

	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);

	wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;

	kfree(buf);
	return 0;

out_free:
	kfree(buf);
	return -EPERM;
}

static void
pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
		struct t10_wwn *wwn)
{
	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
	int ident_len, page_len, off = 4, ret;
	struct t10_vpd *vpd;

	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
	if (!buf)
		return;

	memset(cdb, 0, MAX_COMMAND_SIZE);
	cdb[0] = INQUIRY;
	cdb[1] = 0x01; /* Query VPD */
	cdb[2] = 0x83; /* Device Identifier */
	put_unaligned_be16(INQUIRY_VPD_DEVICE_IDENTIFIER_LEN, &cdb[3]);

	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
			      NULL, HZ, 1, NULL);
	if (ret)
		goto out;

	page_len = get_unaligned_be16(&buf[2]);
	while (page_len > 0) {
		/* Grab a pointer to the Identification descriptor */
		page_83 = &buf[off];
		ident_len = page_83[3];
		if (!ident_len) {
			pr_err("page_83[3]: identifier"
					" length zero!\n");
			break;
		}
		pr_debug("T10 VPD Identifier Length: %d\n", ident_len);

		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
		if (!vpd) {
			pr_err("Unable to allocate memory for"
					" struct t10_vpd\n");
			goto out;
		}
		INIT_LIST_HEAD(&vpd->vpd_list);

		transport_set_vpd_proto_id(vpd, page_83);
		transport_set_vpd_assoc(vpd, page_83);

		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
			off += (ident_len + 4);
			page_len -= (ident_len + 4);
			kfree(vpd);
			continue;
		}
		if (transport_set_vpd_ident(vpd, page_83) < 0) {
			off += (ident_len + 4);
			page_len -= (ident_len + 4);
			kfree(vpd);
			continue;
		}

		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
		off += (ident_len + 4);
		page_len -= (ident_len + 4);
	}

out:
	kfree(buf);
}

static int pscsi_add_device_to_list(struct se_device *dev,
		struct scsi_device *sd)
{
	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
	struct request_queue *q = sd->request_queue;

	pdv->pdv_sd = sd;

	if (!sd->queue_depth) {
		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;

		pr_err("Set broken SCSI Device %d:%d:%llu"
			" queue_depth to %d\n", sd->channel, sd->id,
				sd->lun, sd->queue_depth);
	}

	dev->dev_attrib.hw_block_size =
		min_not_zero((int)sd->sector_size, 512);
	dev->dev_attrib.hw_max_sectors =
		min_not_zero(sd->host->max_sectors, queue_max_hw_sectors(q));
	dev->dev_attrib.hw_queue_depth = sd->queue_depth;

	/*
	 * Setup our standard INQUIRY info into se_dev->t10_wwn
	 */
	pscsi_set_inquiry_info(sd, &dev->t10_wwn);

	/*
	 * Locate VPD WWN Information used for various purposes within
	 * the Storage Engine.
	 */
	if (!pscsi_get_inquiry_vpd_serial(sd, &dev->t10_wwn)) {
		/*
		 * If VPD Unit Serial returned GOOD status, try
		 * VPD Device Identification page (0x83).
		 */
		pscsi_get_inquiry_vpd_device_ident(sd, &dev->t10_wwn);
	}

	/*
	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
	 */
	if (sd->type == TYPE_TAPE) {
		pscsi_tape_read_blocksize(dev, sd);
		dev->dev_attrib.hw_block_size = sd->sector_size;
	}
	return 0;
}

static struct se_device *pscsi_alloc_device(struct se_hba *hba,
		const char *name)
{
	struct pscsi_dev_virt *pdv;

	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
	if (!pdv) {
		pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
		return NULL;
	}

	pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
	return &pdv->dev;
}

/*
 * Called with struct Scsi_Host->host_lock called.
 */
static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
	__releases(sh->host_lock)
{
	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
	struct Scsi_Host *sh = sd->host;
	struct block_device *bd;
	int ret;

	if (scsi_device_get(sd)) {
		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
			sh->host_no, sd->channel, sd->id, sd->lun);
		spin_unlock_irq(sh->host_lock);
		return -EIO;
	}
	spin_unlock_irq(sh->host_lock);
	/*
	 * Claim exclusive struct block_device access to struct scsi_device
	 * for TYPE_DISK and TYPE_ZBC using supplied udev_path
	 */
	bd = blkdev_get_by_path(dev->udev_path,
				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
	if (IS_ERR(bd)) {
		pr_err("pSCSI: blkdev_get_by_path() failed\n");
		scsi_device_put(sd);
		return PTR_ERR(bd);
	}
	pdv->pdv_bd = bd;

	ret = pscsi_add_device_to_list(dev, sd);
	if (ret) {
		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
		scsi_device_put(sd);
		return ret;
	}

	pr_debug("CORE_PSCSI[%d] - Added TYPE_%s for %d:%d:%d:%llu\n",
		phv->phv_host_id, sd->type == TYPE_DISK ? "DISK" : "ZBC",
		sh->host_no, sd->channel, sd->id, sd->lun);
	return 0;
}

/*
 * Called with struct Scsi_Host->host_lock called.
 */
static int pscsi_create_type_nondisk(struct se_device *dev, struct scsi_device *sd)
	__releases(sh->host_lock)
{
	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
	struct Scsi_Host *sh = sd->host;
	int ret;

	if (scsi_device_get(sd)) {
		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
			sh->host_no, sd->channel, sd->id, sd->lun);
		spin_unlock_irq(sh->host_lock);
		return -EIO;
	}
	spin_unlock_irq(sh->host_lock);

	ret = pscsi_add_device_to_list(dev, sd);
	if (ret) {
		scsi_device_put(sd);
		return ret;
	}
	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
		sd->channel, sd->id, sd->lun);

	return 0;
}

static int pscsi_configure_device(struct se_device *dev)
{
	struct se_hba *hba = dev->se_hba;
	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
	struct scsi_device *sd;
	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
	struct Scsi_Host *sh = phv->phv_lld_host;
	int legacy_mode_enable = 0;
	int ret;

	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
		pr_err("Missing scsi_channel_id=, scsi_target_id= and"
			" scsi_lun_id= parameters\n");
		return -EINVAL;
	}

	/*
	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
	 */
	if (!sh) {
		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
			pr_err("pSCSI: Unable to locate struct"
				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
			return -ENODEV;
		}
		/*
		 * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
		 * reference, we enforce that udev_path has been set
		 */
		if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
			pr_err("pSCSI: udev_path attribute has not"
				" been set before ENABLE=1\n");
			return -EINVAL;
		}
		/*
		 * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
		 * use the original TCM hba ID to reference Linux/SCSI Host No
		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
		 */
		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
			if (hba->dev_count) {
				pr_err("pSCSI: Unable to set hba_mode"
					" with active devices\n");
				return -EEXIST;
			}

			if (pscsi_pmode_enable_hba(hba, 1) != 1)
				return -ENODEV;

			legacy_mode_enable = 1;
			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
			sh = phv->phv_lld_host;
		} else {
			sh = scsi_host_lookup(pdv->pdv_host_id);
			if (!sh) {
				pr_err("pSCSI: Unable to locate"
					" pdv_host_id: %d\n", pdv->pdv_host_id);
				return -EINVAL;
			}
			pdv->pdv_lld_host = sh;
		}
	} else {
		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
			pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
				" struct Scsi_Host exists\n");
			return -EEXIST;
		}
	}

	spin_lock_irq(sh->host_lock);
	list_for_each_entry(sd, &sh->__devices, siblings) {
		if ((pdv->pdv_channel_id != sd->channel) ||
		    (pdv->pdv_target_id != sd->id) ||
		    (pdv->pdv_lun_id != sd->lun))
			continue;
		/*
		 * Functions will release the held struct scsi_host->host_lock
		 * before calling pscsi_add_device_to_list() to register
		 * struct scsi_device with target_core_mod.
		 */
		switch (sd->type) {
		case TYPE_DISK:
		case TYPE_ZBC:
			ret = pscsi_create_type_disk(dev, sd);
			break;
		default:
			ret = pscsi_create_type_nondisk(dev, sd);
			break;
		}

		if (ret) {
			if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
				scsi_host_put(sh);
			else if (legacy_mode_enable) {
				pscsi_pmode_enable_hba(hba, 0);
				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
			}
			pdv->pdv_sd = NULL;
			return ret;
		}
		return 0;
	}
	spin_unlock_irq(sh->host_lock);

	pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);

	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
		scsi_host_put(sh);
	else if (legacy_mode_enable) {
		pscsi_pmode_enable_hba(hba, 0);
		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
	}

	return -ENODEV;
}

static void pscsi_dev_call_rcu(struct rcu_head *p)
{
	struct se_device *dev = container_of(p, struct se_device, rcu_head);
	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);

	kfree(pdv);
}

static void pscsi_free_device(struct se_device *dev)
{
	call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
}

static void pscsi_destroy_device(struct se_device *dev)
{
	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
	struct scsi_device *sd = pdv->pdv_sd;

	if (sd) {
		/*
		 * Release exclusive pSCSI internal struct block_device claim for
		 * struct scsi_device with TYPE_DISK or TYPE_ZBC
		 * from pscsi_create_type_disk()
		 */
		if ((sd->type == TYPE_DISK || sd->type == TYPE_ZBC) &&
		    pdv->pdv_bd) {
			blkdev_put(pdv->pdv_bd,
				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
			pdv->pdv_bd = NULL;
		}
		/*
		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
		 * to struct Scsi_Host now.
		 */
		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
		    (phv->phv_lld_host != NULL))
			scsi_host_put(phv->phv_lld_host);
		else if (pdv->pdv_lld_host)
			scsi_host_put(pdv->pdv_lld_host);

		scsi_device_put(sd);

		pdv->pdv_sd = NULL;
	}
}

static void pscsi_complete_cmd(struct se_cmd *cmd, u8 scsi_status,
			       unsigned char *req_sense, int valid_data)
{
	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
	struct scsi_device *sd = pdv->pdv_sd;
	unsigned char *cdb = cmd->priv;

	/*
	 * Special case for REPORT_LUNs which is emulated and not passed on.
	 */
	if (!cdb)
		return;

	/*
	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
	 * forced.
	 */
	if (!cmd->data_length)
		goto after_mode_sense;

	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
	    scsi_status == SAM_STAT_GOOD) {
		bool read_only = target_lun_is_rdonly(cmd);

		if (read_only) {
			unsigned char *buf;

			buf = transport_kmap_data_sg(cmd);
			if (!buf) {
				; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
			} else {
				if (cdb[0] == MODE_SENSE_10) {
					if (!(buf[3] & 0x80))
						buf[3] |= 0x80;
				} else {
					if (!(buf[2] & 0x80))
						buf[2] |= 0x80;
				}

				transport_kunmap_data_sg(cmd);
			}
		}
	}
after_mode_sense:

	if (sd->type != TYPE_TAPE || !cmd->data_length)
		goto after_mode_select;

	/*
	 * Hack to correctly obtain the initiator requested blocksize for
	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
	 * struct scsi_device->sector_size will not contain the correct value
	 * by default, so we go ahead and set it so
	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
	 * storage engine.
	 */
	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
	     scsi_status == SAM_STAT_GOOD) {
		unsigned char *buf;
		u16 bdl;
		u32 blocksize;

		buf = sg_virt(&cmd->t_data_sg[0]);
		if (!buf) {
			pr_err("Unable to get buf for scatterlist\n");
			goto after_mode_select;
		}

		if (cdb[0] == MODE_SELECT)
			bdl = buf[3];
		else
			bdl = get_unaligned_be16(&buf[6]);

		if (!bdl)
			goto after_mode_select;

		if (cdb[0] == MODE_SELECT)
			blocksize = get_unaligned_be24(&buf[9]);
		else
			blocksize = get_unaligned_be24(&buf[13]);

		sd->sector_size = blocksize;
	}
after_mode_select:

	if (scsi_status == SAM_STAT_CHECK_CONDITION) {
		transport_copy_sense_to_cmd(cmd, req_sense);

		/*
		 * check for TAPE device reads with
		 * FM/EOM/ILI set, so that we can get data
		 * back despite framework assumption that a
		 * check condition means there is no data
		 */
		if (sd->type == TYPE_TAPE && valid_data &&
		    cmd->data_direction == DMA_FROM_DEVICE) {
			/*
			 * is sense data valid, fixed format,
			 * and have FM, EOM, or ILI set?
			 */
			if (req_sense[0] == 0xf0 &&	/* valid, fixed format */
			    req_sense[2] & 0xe0 &&	/* FM, EOM, or ILI */
			    (req_sense[2] & 0xf) == 0) { /* key==NO_SENSE */
				pr_debug("Tape FM/EOM/ILI status detected. Treat as normal read.\n");
				cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
			}
		}
	}
}

enum {
	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
	Opt_scsi_lun_id, Opt_err
};

static match_table_t tokens = {
	{Opt_scsi_host_id, "scsi_host_id=%d"},
	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
	{Opt_scsi_target_id, "scsi_target_id=%d"},
	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
	{Opt_err, NULL}
};

static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
		const char *page, ssize_t count)
{
	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
	char *orig, *ptr, *opts;
	substring_t args[MAX_OPT_ARGS];
	int ret = 0, arg, token;

	opts = kstrdup(page, GFP_KERNEL);
	if (!opts)
		return -ENOMEM;

	orig = opts;

	while ((ptr = strsep(&opts, ",\n")) != NULL) {
		if (!*ptr)
			continue;

		token = match_token(ptr, tokens, args);
		switch (token) {
		case Opt_scsi_host_id:
			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
				pr_err("PSCSI[%d]: Unable to accept"
					" scsi_host_id while phv_mode =="
					" PHV_LLD_SCSI_HOST_NO\n",
					phv->phv_host_id);
				ret = -EINVAL;
				goto out;
			}
			ret = match_int(args, &arg);
			if (ret)
				goto out;
			pdv->pdv_host_id = arg;
			pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
			break;
		case Opt_scsi_channel_id:
			ret = match_int(args, &arg);
			if (ret)
				goto out;
			pdv->pdv_channel_id = arg;
			pr_debug("PSCSI[%d]: Referencing SCSI Channel"
				" ID: %d\n",  phv->phv_host_id,
				pdv->pdv_channel_id);
			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
			break;
		case Opt_scsi_target_id:
			ret = match_int(args, &arg);
			if (ret)
				goto out;
			pdv->pdv_target_id = arg;
			pr_debug("PSCSI[%d]: Referencing SCSI Target"
				" ID: %d\n", phv->phv_host_id,
				pdv->pdv_target_id);
			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
			break;
		case Opt_scsi_lun_id:
			ret = match_int(args, &arg);
			if (ret)
				goto out;
			pdv->pdv_lun_id = arg;
			pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
			pdv->pdv_flags |= PDF_HAS_LUN_ID;
			break;
		default:
			break;
		}
	}

out:
	kfree(orig);
	return (!ret) ? count : ret;
}

static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
{
	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
	struct scsi_device *sd = pdv->pdv_sd;
	unsigned char host_id[16];
	ssize_t bl;

	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
	else
		snprintf(host_id, 16, "PHBA Mode");

	bl = sprintf(b, "SCSI Device Bus Location:"
		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
		host_id);

	if (sd) {
		bl += sprintf(b + bl, "        Vendor: %."
			__stringify(INQUIRY_VENDOR_LEN) "s", sd->vendor);
		bl += sprintf(b + bl, " Model: %."
			__stringify(INQUIRY_MODEL_LEN) "s", sd->model);
		bl += sprintf(b + bl, " Rev: %."
			__stringify(INQUIRY_REVISION_LEN) "s\n", sd->rev);
	}
	return bl;
}

static void pscsi_bi_endio(struct bio *bio)
{
	bio_uninit(bio);
	kfree(bio);
}

static sense_reason_t
pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
		struct request *req)
{
	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
	struct bio *bio = NULL;
	struct page *page;
	struct scatterlist *sg;
	u32 data_len = cmd->data_length, i, len, bytes, off;
	int nr_pages = (cmd->data_length + sgl[0].offset +
			PAGE_SIZE - 1) >> PAGE_SHIFT;
	int nr_vecs = 0, rc;
	int rw = (cmd->data_direction == DMA_TO_DEVICE);

	BUG_ON(!cmd->data_length);

	pr_debug("PSCSI: nr_pages: %d\n", nr_pages);

	for_each_sg(sgl, sg, sgl_nents, i) {
		page = sg_page(sg);
		off = sg->offset;
		len = sg->length;

		pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
			page, len, off);

		/*
		 * We only have one page of data in each sg element,
		 * we can not cross a page boundary.
		 */
		if (off + len > PAGE_SIZE)
			goto fail;

		if (len > 0 && data_len > 0) {
			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
			bytes = min(bytes, data_len);

			if (!bio) {
new_bio:
				nr_vecs = bio_max_segs(nr_pages);
				bio = bio_kmalloc(nr_vecs, GFP_KERNEL);
				if (!bio)
					goto fail;
				bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs,
					 rw ? REQ_OP_WRITE : REQ_OP_READ);
				bio->bi_end_io = pscsi_bi_endio;

				pr_debug("PSCSI: Allocated bio: %p,"
					" dir: %s nr_vecs: %d\n", bio,
					(rw) ? "rw" : "r", nr_vecs);
			}

			pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
				" bio: %p page: %p len: %d off: %d\n", i, bio,
				page, len, off);

			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
					bio, page, bytes, off);
			pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
				bio_segments(bio), nr_vecs);
			if (rc != bytes) {
				pr_debug("PSCSI: Reached bio->bi_vcnt max:"
					" %d i: %d bio: %p, allocating another"
					" bio\n", bio->bi_vcnt, i, bio);

				rc = blk_rq_append_bio(req, bio);
				if (rc) {
					pr_err("pSCSI: failed to append bio\n");
					goto fail;
				}

				goto new_bio;
			}

			data_len -= bytes;
		}
	}

	if (bio) {
		rc = blk_rq_append_bio(req, bio);
		if (rc) {
			pr_err("pSCSI: failed to append bio\n");
			goto fail;
		}
	}

	return 0;
fail:
	if (bio)
		bio_put(bio);
	while (req->bio) {
		bio = req->bio;
		req->bio = bio->bi_next;
		bio_put(bio);
	}
	req->biotail = NULL;
	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}

static sense_reason_t
pscsi_parse_cdb(struct se_cmd *cmd)
{
	if (cmd->se_cmd_flags & SCF_BIDI)
		return TCM_UNSUPPORTED_SCSI_OPCODE;

	return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
}

static sense_reason_t
pscsi_execute_cmd(struct se_cmd *cmd)
{
	struct scatterlist *sgl = cmd->t_data_sg;
	u32 sgl_nents = cmd->t_data_nents;
	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
	struct scsi_cmnd *scmd;
	struct request *req;
	sense_reason_t ret;

	req = scsi_alloc_request(pdv->pdv_sd->request_queue,
			cmd->data_direction == DMA_TO_DEVICE ?
			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
	if (IS_ERR(req))
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

	if (sgl) {
		ret = pscsi_map_sg(cmd, sgl, sgl_nents, req);
		if (ret)
			goto fail_put_request;
	}

	req->end_io = pscsi_req_done;
	req->end_io_data = cmd;

	scmd = blk_mq_rq_to_pdu(req);
	scmd->cmd_len = scsi_command_size(cmd->t_task_cdb);
	if (scmd->cmd_len > sizeof(scmd->cmnd)) {
		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		goto fail_put_request;
	}
	memcpy(scmd->cmnd, cmd->t_task_cdb, scmd->cmd_len);

	if (pdv->pdv_sd->type == TYPE_DISK ||
	    pdv->pdv_sd->type == TYPE_ZBC)
		req->timeout = PS_TIMEOUT_DISK;
	else
		req->timeout = PS_TIMEOUT_OTHER;
	scmd->allowed = PS_RETRY;

	cmd->priv = scmd->cmnd;

	blk_execute_rq_nowait(req, cmd->sam_task_attr == TCM_HEAD_TAG);

	return 0;

fail_put_request:
	blk_mq_free_request(req);
	return ret;
}

/*	pscsi_get_device_type():
 *
 *
 */
static u32 pscsi_get_device_type(struct se_device *dev)
{
	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
	struct scsi_device *sd = pdv->pdv_sd;

	return (sd) ? sd->type : TYPE_NO_LUN;
}

static sector_t pscsi_get_blocks(struct se_device *dev)
{
	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);

	if (pdv->pdv_bd)
		return bdev_nr_sectors(pdv->pdv_bd);
	return 0;
}

static enum rq_end_io_ret pscsi_req_done(struct request *req,
					 blk_status_t status)
{
	struct se_cmd *cmd = req->end_io_data;
	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
	enum sam_status scsi_status = scmd->result & 0xff;
	int valid_data = cmd->data_length - scmd->resid_len;
	u8 *cdb = cmd->priv;

	if (scsi_status != SAM_STAT_GOOD) {
		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
			" 0x%02x Result: 0x%08x\n", cmd, cdb[0], scmd->result);
	}

	pscsi_complete_cmd(cmd, scsi_status, scmd->sense_buffer, valid_data);

	switch (host_byte(scmd->result)) {
	case DID_OK:
		target_complete_cmd_with_length(cmd, scsi_status, valid_data);
		break;
	default:
		pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
			" 0x%02x Result: 0x%08x\n", cmd, cdb[0], scmd->result);
		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
		break;
	}

	blk_mq_free_request(req);
	return RQ_END_IO_NONE;
}

static const struct target_backend_ops pscsi_ops = {
	.name			= "pscsi",
	.owner			= THIS_MODULE,
	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH |
				   TRANSPORT_FLAG_PASSTHROUGH_ALUA |
				   TRANSPORT_FLAG_PASSTHROUGH_PGR,
	.attach_hba		= pscsi_attach_hba,
	.detach_hba		= pscsi_detach_hba,
	.pmode_enable_hba	= pscsi_pmode_enable_hba,
	.alloc_device		= pscsi_alloc_device,
	.configure_device	= pscsi_configure_device,
	.destroy_device		= pscsi_destroy_device,
	.free_device		= pscsi_free_device,
	.parse_cdb		= pscsi_parse_cdb,
	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
	.get_device_type	= pscsi_get_device_type,
	.get_blocks		= pscsi_get_blocks,
	.tb_dev_attrib_attrs	= passthrough_attrib_attrs,
};

static int __init pscsi_module_init(void)
{
	return transport_backend_register(&pscsi_ops);
}

static void __exit pscsi_module_exit(void)
{
	target_backend_unregister(&pscsi_ops);
}

MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
MODULE_AUTHOR("nab@Linux-iSCSI.org");
MODULE_LICENSE("GPL");

module_init(pscsi_module_init);
module_exit(pscsi_module_exit);