summaryrefslogtreecommitdiff
path: root/drivers/target/target_core_xcopy.c
blob: b09b40e058a0ccbf32105e2cb6d979c10c90a210 (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
1073
/*******************************************************************************
 * Filename: target_core_xcopy.c
 *
 * This file contains support for SPC-4 Extended-Copy offload with generic
 * TCM backends.
 *
 * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
 *
 * Author:
 * Nicholas A. Bellinger <nab@daterainc.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that 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.
 *
 ******************************************************************************/

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/configfs.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <asm/unaligned.h>

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

#include "target_core_internal.h"
#include "target_core_pr.h"
#include "target_core_ua.h"
#include "target_core_xcopy.h"

static struct workqueue_struct *xcopy_wq = NULL;

static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
{
	int off = 0;

	buf[off++] = (0x6 << 4);
	buf[off++] = 0x01;
	buf[off++] = 0x40;
	buf[off] = (0x5 << 4);

	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
	return 0;
}

static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
					bool src)
{
	struct se_device *se_dev;
	struct configfs_subsystem *subsys = target_core_subsystem[0];
	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN], *dev_wwn;
	int rc;

	if (src)
		dev_wwn = &xop->dst_tid_wwn[0];
	else
		dev_wwn = &xop->src_tid_wwn[0];

	mutex_lock(&g_device_mutex);
	list_for_each_entry(se_dev, &g_device_list, g_dev_node) {

		if (!se_dev->dev_attrib.emulate_3pc)
			continue;

		memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
		target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);

		rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
		if (rc != 0)
			continue;

		if (src) {
			xop->dst_dev = se_dev;
			pr_debug("XCOPY 0xe4: Setting xop->dst_dev: %p from located"
				" se_dev\n", xop->dst_dev);
		} else {
			xop->src_dev = se_dev;
			pr_debug("XCOPY 0xe4: Setting xop->src_dev: %p from located"
				" se_dev\n", xop->src_dev);
		}

		rc = configfs_depend_item(subsys,
				&se_dev->dev_group.cg_item);
		if (rc != 0) {
			pr_err("configfs_depend_item attempt failed:"
				" %d for se_dev: %p\n", rc, se_dev);
			mutex_unlock(&g_device_mutex);
			return rc;
		}

		pr_debug("Called configfs_depend_item for subsys: %p se_dev: %p"
			" se_dev->se_dev_group: %p\n", subsys, se_dev,
			&se_dev->dev_group);

		mutex_unlock(&g_device_mutex);
		return 0;
	}
	mutex_unlock(&g_device_mutex);

	pr_err("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
	return -EINVAL;
}

static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
				unsigned char *p, bool src)
{
	unsigned char *desc = p;
	unsigned short ript;
	u8 desig_len;
	/*
	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
	 */
	ript = get_unaligned_be16(&desc[2]);
	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
	/*
	 * Check for supported code set, association, and designator type
	 */
	if ((desc[4] & 0x0f) != 0x1) {
		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
		return -EINVAL;
	}
	if ((desc[5] & 0x30) != 0x00) {
		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
		return -EINVAL;
	}
	if ((desc[5] & 0x0f) != 0x3) {
		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
				(desc[5] & 0x0f));
		return -EINVAL;
	}
	/*
	 * Check for matching 16 byte length for NAA IEEE Registered Extended
	 * Assigned designator
	 */
	desig_len = desc[7];
	if (desig_len != 16) {
		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
		return -EINVAL;
	}
	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
	/*
	 * Check for NAA IEEE Registered Extended Assigned header..
	 */
	if ((desc[8] & 0xf0) != 0x60) {
		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
					(desc[8] & 0xf0));
		return -EINVAL;
	}

	if (src) {
		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
		/*
		 * Determine if the source designator matches the local device
		 */
		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
				XCOPY_NAA_IEEE_REGEX_LEN)) {
			xop->op_origin = XCOL_SOURCE_RECV_OP;
			xop->src_dev = se_cmd->se_dev;
			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
					" received xop\n", xop->src_dev);
		}
	} else {
		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
		/*
		 * Determine if the destination designator matches the local device
		 */
		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
				XCOPY_NAA_IEEE_REGEX_LEN)) {
			xop->op_origin = XCOL_DEST_RECV_OP;
			xop->dst_dev = se_cmd->se_dev;
			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
				" received xop\n", xop->dst_dev);
		}
	}

	return 0;
}

static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
				struct xcopy_op *xop, unsigned char *p,
				unsigned short tdll)
{
	struct se_device *local_dev = se_cmd->se_dev;
	unsigned char *desc = p;
	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc, ret = 0;
	unsigned short start = 0;
	bool src = true;

	if (offset != 0) {
		pr_err("XCOPY target descriptor list length is not"
			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
		return -EINVAL;
	}
	if (tdll > 64) {
		pr_err("XCOPY target descriptor supports a maximum"
			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
		return -EINVAL;
	}
	/*
	 * Generate an IEEE Registered Extended designator based upon the
	 * se_device the XCOPY was received upon..
	 */
	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
	target_xcopy_gen_naa_ieee(local_dev, &xop->local_dev_wwn[0]);

	while (start < tdll) {
		/*
		 * Check target descriptor identification with 0xE4 type with
		 * use VPD 0x83 WWPN matching ..
		 */
		switch (desc[0]) {
		case 0xe4:
			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
							&desc[0], src);
			if (rc != 0)
				goto out;
			/*
			 * Assume target descriptors are in source -> destination order..
			 */
			if (src)
				src = false;
			else
				src = true;
			start += XCOPY_TARGET_DESC_LEN;
			desc += XCOPY_TARGET_DESC_LEN;
			ret++;
			break;
		default:
			pr_err("XCOPY unsupported descriptor type code:"
					" 0x%02x\n", desc[0]);
			goto out;
		}
	}

	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, true);
	else
		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, false);

	if (rc < 0)
		goto out;

	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
		 xop->src_dev, &xop->src_tid_wwn[0]);
	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
		 xop->dst_dev, &xop->dst_tid_wwn[0]);

	return ret;

out:
	return -EINVAL;
}

static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop,
					unsigned char *p)
{
	unsigned char *desc = p;
	int dc = (desc[1] & 0x02);
	unsigned short desc_len;

	desc_len = get_unaligned_be16(&desc[2]);
	if (desc_len != 0x18) {
		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
				" %hu\n", desc_len);
		return -EINVAL;
	}

	xop->stdi = get_unaligned_be16(&desc[4]);
	xop->dtdi = get_unaligned_be16(&desc[6]);
	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
		desc_len, xop->stdi, xop->dtdi, dc);

	xop->nolb = get_unaligned_be16(&desc[10]);
	xop->src_lba = get_unaligned_be64(&desc[12]);
	xop->dst_lba = get_unaligned_be64(&desc[20]);
	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
		xop->nolb, (unsigned long long)xop->src_lba,
		(unsigned long long)xop->dst_lba);

	if (dc != 0) {
		xop->dbl = (desc[29] & 0xff) << 16;
		xop->dbl |= (desc[30] & 0xff) << 8;
		xop->dbl |= desc[31] & 0xff;

		pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl);
	}
	return 0;
}

static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
				struct xcopy_op *xop, unsigned char *p,
				unsigned int sdll)
{
	unsigned char *desc = p;
	unsigned int start = 0;
	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;

	if (offset != 0) {
		pr_err("XCOPY segment descriptor list length is not"
			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
		return -EINVAL;
	}

	while (start < sdll) {
		/*
		 * Check segment descriptor type code for block -> block
		 */
		switch (desc[0]) {
		case 0x02:
			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
			if (rc < 0)
				goto out;

			ret++;
			start += XCOPY_SEGMENT_DESC_LEN;
			desc += XCOPY_SEGMENT_DESC_LEN;
			break;
		default:
			pr_err("XCOPY unsupported segment descriptor"
				"type: 0x%02x\n", desc[0]);
			goto out;
		}
	}

	return ret;

out:
	return -EINVAL;
}

/*
 * Start xcopy_pt ops
 */

struct xcopy_pt_cmd {
	bool remote_port;
	struct se_cmd se_cmd;
	struct xcopy_op *xcopy_op;
	struct completion xpt_passthrough_sem;
	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
};

static struct se_port xcopy_pt_port;
static struct se_portal_group xcopy_pt_tpg;
static struct se_session xcopy_pt_sess;
static struct se_node_acl xcopy_pt_nacl;

static char *xcopy_pt_get_fabric_name(void)
{
        return "xcopy-pt";
}

static u32 xcopy_pt_get_tag(struct se_cmd *se_cmd)
{
        return 0;
}

static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
{
        return 0;
}

static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
{
	struct configfs_subsystem *subsys = target_core_subsystem[0];
	struct se_device *remote_dev;

	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
		remote_dev = xop->dst_dev;
	else
		remote_dev = xop->src_dev;

	pr_debug("Calling configfs_undepend_item for subsys: %p"
		  " remote_dev: %p remote_dev->dev_group: %p\n",
		  subsys, remote_dev, &remote_dev->dev_group.cg_item);

	configfs_undepend_item(subsys, &remote_dev->dev_group.cg_item);
}

static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
{
	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
				struct xcopy_pt_cmd, se_cmd);

	kfree(xpt_cmd);
}

static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
{
	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
				struct xcopy_pt_cmd, se_cmd);

	complete(&xpt_cmd->xpt_passthrough_sem);
	return 0;
}

static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
{
	return 0;
}

static int xcopy_pt_write_pending_status(struct se_cmd *se_cmd)
{
	return 0;
}

static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
{
	return 0;
}

static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
{
	return 0;
}

static struct target_core_fabric_ops xcopy_pt_tfo = {
	.get_fabric_name	= xcopy_pt_get_fabric_name,
	.get_task_tag		= xcopy_pt_get_tag,
	.get_cmd_state		= xcopy_pt_get_cmd_state,
	.release_cmd		= xcopy_pt_release_cmd,
	.check_stop_free	= xcopy_pt_check_stop_free,
	.write_pending		= xcopy_pt_write_pending,
	.write_pending_status	= xcopy_pt_write_pending_status,
	.queue_data_in		= xcopy_pt_queue_data_in,
	.queue_status		= xcopy_pt_queue_status,
};

/*
 * End xcopy_pt_ops
 */

int target_xcopy_setup_pt(void)
{
	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
	if (!xcopy_wq) {
		pr_err("Unable to allocate xcopy_wq\n");
		return -ENOMEM;
	}

	memset(&xcopy_pt_port, 0, sizeof(struct se_port));
	INIT_LIST_HEAD(&xcopy_pt_port.sep_alua_list);
	INIT_LIST_HEAD(&xcopy_pt_port.sep_list);
	mutex_init(&xcopy_pt_port.sep_tg_pt_md_mutex);

	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
	INIT_LIST_HEAD(&xcopy_pt_tpg.se_tpg_node);
	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);

	xcopy_pt_port.sep_tpg = &xcopy_pt_tpg;
	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;

	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
	INIT_LIST_HEAD(&xcopy_pt_sess.sess_list);
	INIT_LIST_HEAD(&xcopy_pt_sess.sess_acl_list);

	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;

	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;

	return 0;
}

void target_xcopy_release_pt(void)
{
	if (xcopy_wq)
		destroy_workqueue(xcopy_wq);
}

static void target_xcopy_setup_pt_port(
	struct xcopy_pt_cmd *xpt_cmd,
	struct xcopy_op *xop,
	bool remote_port)
{
	struct se_cmd *ec_cmd = xop->xop_se_cmd;
	struct se_cmd *pt_cmd = &xpt_cmd->se_cmd;

	if (xop->op_origin == XCOL_SOURCE_RECV_OP) {
		/*
		 * Honor destination port reservations for X-COPY PUSH emulation
		 * when CDB is received on local source port, and READs blocks to
		 * WRITE on remote destination port.
		 */
		if (remote_port) {
			xpt_cmd->remote_port = remote_port;
			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
			pr_debug("Setup emulated remote DEST xcopy_pt_port: %p to"
				" cmd->se_lun->lun_sep for X-COPY data PUSH\n",
				pt_cmd->se_lun->lun_sep);
		} else {
			pt_cmd->se_lun = ec_cmd->se_lun;
			pt_cmd->se_dev = ec_cmd->se_dev;

			pr_debug("Honoring local SRC port from ec_cmd->se_dev:"
				" %p\n", pt_cmd->se_dev);
			pt_cmd->se_lun = ec_cmd->se_lun;
			pr_debug("Honoring local SRC port from ec_cmd->se_lun: %p\n",
				pt_cmd->se_lun);
		}
	} else {
		/*
		 * Honor source port reservation for X-COPY PULL emulation
		 * when CDB is received on local desintation port, and READs
		 * blocks from the remote source port to WRITE on local
		 * destination port.
		 */
		if (remote_port) {
			xpt_cmd->remote_port = remote_port;
			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
			pr_debug("Setup emulated remote SRC xcopy_pt_port: %p to"
				" cmd->se_lun->lun_sep for X-COPY data PULL\n",
				pt_cmd->se_lun->lun_sep);
		} else {
			pt_cmd->se_lun = ec_cmd->se_lun;
			pt_cmd->se_dev = ec_cmd->se_dev;

			pr_debug("Honoring local DST port from ec_cmd->se_dev:"
				" %p\n", pt_cmd->se_dev);
			pt_cmd->se_lun = ec_cmd->se_lun;
			pr_debug("Honoring local DST port from ec_cmd->se_lun: %p\n",
				pt_cmd->se_lun);
		}
	}
}

static int target_xcopy_init_pt_lun(
	struct xcopy_pt_cmd *xpt_cmd,
	struct xcopy_op *xop,
	struct se_device *se_dev,
	struct se_cmd *pt_cmd,
	bool remote_port)
{
	/*
	 * Don't allocate + init an pt_cmd->se_lun if honoring local port for
	 * reservations.  The pt_cmd->se_lun pointer will be setup from within
	 * target_xcopy_setup_pt_port()
	 */
	if (!remote_port) {
		pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
		return 0;
	}

	pt_cmd->se_lun = &se_dev->xcopy_lun;
	pt_cmd->se_dev = se_dev;

	pr_debug("Setup emulated se_dev: %p from se_dev\n", pt_cmd->se_dev);
	pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;

	pr_debug("Setup emulated se_dev: %p to pt_cmd->se_lun->lun_se_dev\n",
		pt_cmd->se_lun->lun_se_dev);

	return 0;
}

static int target_xcopy_setup_pt_cmd(
	struct xcopy_pt_cmd *xpt_cmd,
	struct xcopy_op *xop,
	struct se_device *se_dev,
	unsigned char *cdb,
	bool remote_port,
	bool alloc_mem)
{
	struct se_cmd *cmd = &xpt_cmd->se_cmd;
	sense_reason_t sense_rc;
	int ret = 0, rc;
	/*
	 * Setup LUN+port to honor reservations based upon xop->op_origin for
	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
	 */
	rc = target_xcopy_init_pt_lun(xpt_cmd, xop, se_dev, cmd, remote_port);
	if (rc < 0) {
		ret = rc;
		goto out;
	}
	xpt_cmd->xcopy_op = xop;
	target_xcopy_setup_pt_port(xpt_cmd, xop, remote_port);

	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
	if (sense_rc) {
		ret = -EINVAL;
		goto out;
	}

	if (alloc_mem) {
		rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
				      cmd->data_length, false);
		if (rc < 0) {
			ret = rc;
			goto out;
		}
		/*
		 * Set this bit so that transport_free_pages() allows the
		 * caller to release SGLs + physical memory allocated by
		 * transport_generic_get_mem()..
		 */
		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
	} else {
		/*
		 * Here the previously allocated SGLs for the internal READ
		 * are mapped zero-copy to the internal WRITE.
		 */
		sense_rc = transport_generic_map_mem_to_cmd(cmd,
					xop->xop_data_sg, xop->xop_data_nents,
					NULL, 0);
		if (sense_rc) {
			ret = -EINVAL;
			goto out;
		}

		pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
			 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
	}

	return 0;

out:
	return ret;
}

static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
{
	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
	sense_reason_t sense_rc;

	sense_rc = transport_generic_new_cmd(se_cmd);
	if (sense_rc)
		return -EINVAL;

	if (se_cmd->data_direction == DMA_TO_DEVICE)
		target_execute_cmd(se_cmd);

	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);

	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
			se_cmd->scsi_status);

	return (se_cmd->scsi_status) ? -EINVAL : 0;
}

static int target_xcopy_read_source(
	struct se_cmd *ec_cmd,
	struct xcopy_op *xop,
	struct se_device *src_dev,
	sector_t src_lba,
	u32 src_sectors)
{
	struct xcopy_pt_cmd *xpt_cmd;
	struct se_cmd *se_cmd;
	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
	int rc;
	unsigned char cdb[16];
	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);

	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
	if (!xpt_cmd) {
		pr_err("Unable to allocate xcopy_pt_cmd\n");
		return -ENOMEM;
	}
	init_completion(&xpt_cmd->xpt_passthrough_sem);
	se_cmd = &xpt_cmd->se_cmd;

	memset(&cdb[0], 0, 16);
	cdb[0] = READ_16;
	put_unaligned_be64(src_lba, &cdb[2]);
	put_unaligned_be32(src_sectors, &cdb[10]);
	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
		(unsigned long long)src_lba, src_sectors, length);

	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
			      DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
	xop->src_pt_cmd = xpt_cmd;

	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
				remote_port, true);
	if (rc < 0) {
		transport_generic_free_cmd(se_cmd, 0);
		return rc;
	}

	xop->xop_data_sg = se_cmd->t_data_sg;
	xop->xop_data_nents = se_cmd->t_data_nents;
	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
		" memory\n", xop->xop_data_sg, xop->xop_data_nents);

	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
	if (rc < 0) {
		transport_generic_free_cmd(se_cmd, 0);
		return rc;
	}
	/*
	 * Clear off the allocated t_data_sg, that has been saved for
	 * zero-copy WRITE submission reuse in struct xcopy_op..
	 */
	se_cmd->t_data_sg = NULL;
	se_cmd->t_data_nents = 0;

	return 0;
}

static int target_xcopy_write_destination(
	struct se_cmd *ec_cmd,
	struct xcopy_op *xop,
	struct se_device *dst_dev,
	sector_t dst_lba,
	u32 dst_sectors)
{
	struct xcopy_pt_cmd *xpt_cmd;
	struct se_cmd *se_cmd;
	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
	int rc;
	unsigned char cdb[16];
	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);

	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
	if (!xpt_cmd) {
		pr_err("Unable to allocate xcopy_pt_cmd\n");
		return -ENOMEM;
	}
	init_completion(&xpt_cmd->xpt_passthrough_sem);
	se_cmd = &xpt_cmd->se_cmd;

	memset(&cdb[0], 0, 16);
	cdb[0] = WRITE_16;
	put_unaligned_be64(dst_lba, &cdb[2]);
	put_unaligned_be32(dst_sectors, &cdb[10]);
	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
		(unsigned long long)dst_lba, dst_sectors, length);

	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
			      DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
	xop->dst_pt_cmd = xpt_cmd;

	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
				remote_port, false);
	if (rc < 0) {
		struct se_cmd *src_cmd = &xop->src_pt_cmd->se_cmd;
		/*
		 * If the failure happened before the t_mem_list hand-off in
		 * target_xcopy_setup_pt_cmd(), Reset memory + clear flag so that
		 * core releases this memory on error during X-COPY WRITE I/O.
		 */
		src_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
		src_cmd->t_data_sg = xop->xop_data_sg;
		src_cmd->t_data_nents = xop->xop_data_nents;

		transport_generic_free_cmd(se_cmd, 0);
		return rc;
	}

	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
	if (rc < 0) {
		se_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
		transport_generic_free_cmd(se_cmd, 0);
		return rc;
	}

	return 0;
}

static void target_xcopy_do_work(struct work_struct *work)
{
	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
	struct se_device *src_dev = xop->src_dev, *dst_dev = xop->dst_dev;
	struct se_cmd *ec_cmd = xop->xop_se_cmd;
	sector_t src_lba = xop->src_lba, dst_lba = xop->dst_lba, end_lba;
	unsigned int max_sectors;
	int rc;
	unsigned short nolb = xop->nolb, cur_nolb, max_nolb, copied_nolb = 0;

	end_lba = src_lba + nolb;
	/*
	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
	 * smallest max_sectors between src_dev + dev_dev, or
	 */
	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
			  dst_dev->dev_attrib.hw_max_sectors);
	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);

	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));

	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
			nolb, max_nolb, (unsigned long long)end_lba);
	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
			(unsigned long long)src_lba, (unsigned long long)dst_lba);

	while (src_lba < end_lba) {
		cur_nolb = min(nolb, max_nolb);

		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);

		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
		if (rc < 0)
			goto out;

		src_lba += cur_nolb;
		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
				(unsigned long long)src_lba);

		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);

		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
						dst_lba, cur_nolb);
		if (rc < 0) {
			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
			goto out;
		}

		dst_lba += cur_nolb;
		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
				(unsigned long long)dst_lba);

		copied_nolb += cur_nolb;
		nolb -= cur_nolb;

		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
		xop->dst_pt_cmd->se_cmd.se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;

		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
	}

	xcopy_pt_undepend_remotedev(xop);
	kfree(xop);

	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
		(unsigned long long)src_lba, (unsigned long long)dst_lba);
	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);

	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
	return;

out:
	xcopy_pt_undepend_remotedev(xop);
	kfree(xop);

	pr_warn("target_xcopy_do_work: Setting X-COPY CHECK_CONDITION -> sending response\n");
	ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
	target_complete_cmd(ec_cmd, SAM_STAT_CHECK_CONDITION);
}

sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
{
	struct se_device *dev = se_cmd->se_dev;
	struct xcopy_op *xop = NULL;
	unsigned char *p = NULL, *seg_desc;
	unsigned int list_id, list_id_usage, sdll, inline_dl, sa;
	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
	int rc;
	unsigned short tdll;

	if (!dev->dev_attrib.emulate_3pc) {
		pr_err("EXTENDED_COPY operation explicitly disabled\n");
		return TCM_UNSUPPORTED_SCSI_OPCODE;
	}

	sa = se_cmd->t_task_cdb[1] & 0x1f;
	if (sa != 0x00) {
		pr_err("EXTENDED_COPY(LID4) not supported\n");
		return TCM_UNSUPPORTED_SCSI_OPCODE;
	}

	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
	if (!xop) {
		pr_err("Unable to allocate xcopy_op\n");
		return TCM_OUT_OF_RESOURCES;
	}
	xop->xop_se_cmd = se_cmd;

	p = transport_kmap_data_sg(se_cmd);
	if (!p) {
		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
		kfree(xop);
		return TCM_OUT_OF_RESOURCES;
	}

	list_id = p[0];
	list_id_usage = (p[1] & 0x18) >> 3;

	/*
	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
	 */
	tdll = get_unaligned_be16(&p[2]);
	sdll = get_unaligned_be32(&p[8]);

	inline_dl = get_unaligned_be32(&p[12]);
	if (inline_dl != 0) {
		pr_err("XCOPY with non zero inline data length\n");
		goto out;
	}

	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
		tdll, sdll, inline_dl);

	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll);
	if (rc <= 0)
		goto out;

	if (xop->src_dev->dev_attrib.block_size !=
	    xop->dst_dev->dev_attrib.block_size) {
		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
		       " block_size: %u currently unsupported\n",
			xop->src_dev->dev_attrib.block_size,
			xop->dst_dev->dev_attrib.block_size);
		xcopy_pt_undepend_remotedev(xop);
		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		goto out;
	}

	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
				rc * XCOPY_TARGET_DESC_LEN);
	seg_desc = &p[16];
	seg_desc += (rc * XCOPY_TARGET_DESC_LEN);

	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc, sdll);
	if (rc <= 0) {
		xcopy_pt_undepend_remotedev(xop);
		goto out;
	}
	transport_kunmap_data_sg(se_cmd);

	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
				rc * XCOPY_SEGMENT_DESC_LEN);
	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
	queue_work(xcopy_wq, &xop->xop_work);
	return TCM_NO_SENSE;

out:
	if (p)
		transport_kunmap_data_sg(se_cmd);
	kfree(xop);
	return ret;
}

static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
{
	unsigned char *p;

	p = transport_kmap_data_sg(se_cmd);
	if (!p) {
		pr_err("transport_kmap_data_sg failed in"
		       " target_rcr_operating_parameters\n");
		return TCM_OUT_OF_RESOURCES;
	}

	if (se_cmd->data_length < 54) {
		pr_err("Receive Copy Results Op Parameters length"
		       " too small: %u\n", se_cmd->data_length);
		transport_kunmap_data_sg(se_cmd);
		return TCM_INVALID_CDB_FIELD;
	}
	/*
	 * Set SNLID=1 (Supports no List ID)
	 */
	p[4] = 0x1;
	/*
	 * MAXIMUM TARGET DESCRIPTOR COUNT
	 */
	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
	/*
	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
	 */
	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
	/*
	 * MAXIMUM DESCRIPTOR LIST LENGTH
	 */
	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
	/*
	 * MAXIMUM SEGMENT LENGTH
	 */
	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
	/*
	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
	 */
	put_unaligned_be32(0x0, &p[20]);
	/*
	 * HELD DATA LIMIT
	 */
	put_unaligned_be32(0x0, &p[24]);
	/*
	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
	 */
	put_unaligned_be32(0x0, &p[28]);
	/*
	 * TOTAL CONCURRENT COPIES
	 */
	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
	/*
	 * MAXIMUM CONCURRENT COPIES
	 */
	p[36] = RCR_OP_MAX_CONCURR_COPIES;
	/*
	 * DATA SEGMENT GRANULARITY (log 2)
	 */
	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
	/*
	 * INLINE DATA GRANULARITY log 2)
	 */
	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
	/*
	 * HELD DATA GRANULARITY
	 */
	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
	/*
	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
	 */
	p[43] = 0x2;
	/*
	 * List of implemented descriptor type codes (ordered)
	 */
	p[44] = 0x02; /* Copy Block to Block device */
	p[45] = 0xe4; /* Identification descriptor target descriptor */

	/*
	 * AVAILABLE DATA (n-3)
	 */
	put_unaligned_be32(42, &p[0]);

	transport_kunmap_data_sg(se_cmd);
	target_complete_cmd(se_cmd, GOOD);

	return TCM_NO_SENSE;
}

sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
{
	unsigned char *cdb = &se_cmd->t_task_cdb[0];
	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
	sense_reason_t rc = TCM_NO_SENSE;

	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);

	if (list_id != 0) {
		pr_err("Receive Copy Results with non zero list identifier"
		       " not supported\n");
		return TCM_INVALID_CDB_FIELD;
	}

	switch (sa) {
	case RCR_SA_OPERATING_PARAMETERS:
		rc = target_rcr_operating_parameters(se_cmd);
		break;
	case RCR_SA_COPY_STATUS:
	case RCR_SA_RECEIVE_DATA:
	case RCR_SA_FAILED_SEGMENT_DETAILS:
	default:
		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
		return TCM_INVALID_CDB_FIELD;
	}

	return rc;
}