xref: /linux/drivers/target/target_core_xcopy.c (revision 3e44c471a2dab210f7e9b1e5f7d4d54d52df59eb)
1 /*******************************************************************************
2  * Filename: target_core_xcopy.c
3  *
4  * This file contains support for SPC-4 Extended-Copy offload with generic
5  * TCM backends.
6  *
7  * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
8  *
9  * Author:
10  * Nicholas A. Bellinger <nab@daterainc.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  ******************************************************************************/
23 
24 #include <linux/slab.h>
25 #include <linux/spinlock.h>
26 #include <linux/list.h>
27 #include <linux/configfs.h>
28 #include <scsi/scsi_proto.h>
29 #include <asm/unaligned.h>
30 
31 #include <target/target_core_base.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_fabric.h>
34 #include <target/target_core_configfs.h>
35 
36 #include "target_core_internal.h"
37 #include "target_core_pr.h"
38 #include "target_core_ua.h"
39 #include "target_core_xcopy.h"
40 
41 static struct workqueue_struct *xcopy_wq = NULL;
42 
43 static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
44 {
45 	int off = 0;
46 
47 	buf[off++] = (0x6 << 4);
48 	buf[off++] = 0x01;
49 	buf[off++] = 0x40;
50 	buf[off] = (0x5 << 4);
51 
52 	spc_parse_naa_6h_vendor_specific(dev, &buf[off]);
53 	return 0;
54 }
55 
56 static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
57 					bool src)
58 {
59 	struct se_device *se_dev;
60 	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN], *dev_wwn;
61 	int rc;
62 
63 	if (src)
64 		dev_wwn = &xop->dst_tid_wwn[0];
65 	else
66 		dev_wwn = &xop->src_tid_wwn[0];
67 
68 	mutex_lock(&g_device_mutex);
69 	list_for_each_entry(se_dev, &g_device_list, g_dev_node) {
70 
71 		if (!se_dev->dev_attrib.emulate_3pc)
72 			continue;
73 
74 		memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
75 		target_xcopy_gen_naa_ieee(se_dev, &tmp_dev_wwn[0]);
76 
77 		rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
78 		if (rc != 0)
79 			continue;
80 
81 		if (src) {
82 			xop->dst_dev = se_dev;
83 			pr_debug("XCOPY 0xe4: Setting xop->dst_dev: %p from located"
84 				" se_dev\n", xop->dst_dev);
85 		} else {
86 			xop->src_dev = se_dev;
87 			pr_debug("XCOPY 0xe4: Setting xop->src_dev: %p from located"
88 				" se_dev\n", xop->src_dev);
89 		}
90 
91 		rc = target_depend_item(&se_dev->dev_group.cg_item);
92 		if (rc != 0) {
93 			pr_err("configfs_depend_item attempt failed:"
94 				" %d for se_dev: %p\n", rc, se_dev);
95 			mutex_unlock(&g_device_mutex);
96 			return rc;
97 		}
98 
99 		pr_debug("Called configfs_depend_item for se_dev: %p"
100 			" se_dev->se_dev_group: %p\n", se_dev,
101 			&se_dev->dev_group);
102 
103 		mutex_unlock(&g_device_mutex);
104 		return 0;
105 	}
106 	mutex_unlock(&g_device_mutex);
107 
108 	pr_err("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
109 	return -EINVAL;
110 }
111 
112 static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
113 				unsigned char *p, bool src)
114 {
115 	unsigned char *desc = p;
116 	unsigned short ript;
117 	u8 desig_len;
118 	/*
119 	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
120 	 */
121 	ript = get_unaligned_be16(&desc[2]);
122 	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
123 	/*
124 	 * Check for supported code set, association, and designator type
125 	 */
126 	if ((desc[4] & 0x0f) != 0x1) {
127 		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
128 		return -EINVAL;
129 	}
130 	if ((desc[5] & 0x30) != 0x00) {
131 		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
132 		return -EINVAL;
133 	}
134 	if ((desc[5] & 0x0f) != 0x3) {
135 		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
136 				(desc[5] & 0x0f));
137 		return -EINVAL;
138 	}
139 	/*
140 	 * Check for matching 16 byte length for NAA IEEE Registered Extended
141 	 * Assigned designator
142 	 */
143 	desig_len = desc[7];
144 	if (desig_len != 16) {
145 		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
146 		return -EINVAL;
147 	}
148 	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
149 	/*
150 	 * Check for NAA IEEE Registered Extended Assigned header..
151 	 */
152 	if ((desc[8] & 0xf0) != 0x60) {
153 		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
154 					(desc[8] & 0xf0));
155 		return -EINVAL;
156 	}
157 
158 	if (src) {
159 		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
160 		/*
161 		 * Determine if the source designator matches the local device
162 		 */
163 		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
164 				XCOPY_NAA_IEEE_REGEX_LEN)) {
165 			xop->op_origin = XCOL_SOURCE_RECV_OP;
166 			xop->src_dev = se_cmd->se_dev;
167 			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
168 					" received xop\n", xop->src_dev);
169 		}
170 	} else {
171 		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
172 		/*
173 		 * Determine if the destination designator matches the local device
174 		 */
175 		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
176 				XCOPY_NAA_IEEE_REGEX_LEN)) {
177 			xop->op_origin = XCOL_DEST_RECV_OP;
178 			xop->dst_dev = se_cmd->se_dev;
179 			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
180 				" received xop\n", xop->dst_dev);
181 		}
182 	}
183 
184 	return 0;
185 }
186 
187 static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
188 				struct xcopy_op *xop, unsigned char *p,
189 				unsigned short tdll)
190 {
191 	struct se_device *local_dev = se_cmd->se_dev;
192 	unsigned char *desc = p;
193 	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc, ret = 0;
194 	unsigned short start = 0;
195 	bool src = true;
196 
197 	if (offset != 0) {
198 		pr_err("XCOPY target descriptor list length is not"
199 			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
200 		return -EINVAL;
201 	}
202 	if (tdll > 64) {
203 		pr_err("XCOPY target descriptor supports a maximum"
204 			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
205 		return -EINVAL;
206 	}
207 	/*
208 	 * Generate an IEEE Registered Extended designator based upon the
209 	 * se_device the XCOPY was received upon..
210 	 */
211 	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
212 	target_xcopy_gen_naa_ieee(local_dev, &xop->local_dev_wwn[0]);
213 
214 	while (start < tdll) {
215 		/*
216 		 * Check target descriptor identification with 0xE4 type with
217 		 * use VPD 0x83 WWPN matching ..
218 		 */
219 		switch (desc[0]) {
220 		case 0xe4:
221 			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
222 							&desc[0], src);
223 			if (rc != 0)
224 				goto out;
225 			/*
226 			 * Assume target descriptors are in source -> destination order..
227 			 */
228 			if (src)
229 				src = false;
230 			else
231 				src = true;
232 			start += XCOPY_TARGET_DESC_LEN;
233 			desc += XCOPY_TARGET_DESC_LEN;
234 			ret++;
235 			break;
236 		default:
237 			pr_err("XCOPY unsupported descriptor type code:"
238 					" 0x%02x\n", desc[0]);
239 			goto out;
240 		}
241 	}
242 
243 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
244 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, true);
245 	else
246 		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, false);
247 
248 	if (rc < 0)
249 		goto out;
250 
251 	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
252 		 xop->src_dev, &xop->src_tid_wwn[0]);
253 	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
254 		 xop->dst_dev, &xop->dst_tid_wwn[0]);
255 
256 	return ret;
257 
258 out:
259 	return -EINVAL;
260 }
261 
262 static int target_xcopy_parse_segdesc_02(struct se_cmd *se_cmd, struct xcopy_op *xop,
263 					unsigned char *p)
264 {
265 	unsigned char *desc = p;
266 	int dc = (desc[1] & 0x02);
267 	unsigned short desc_len;
268 
269 	desc_len = get_unaligned_be16(&desc[2]);
270 	if (desc_len != 0x18) {
271 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
272 				" %hu\n", desc_len);
273 		return -EINVAL;
274 	}
275 
276 	xop->stdi = get_unaligned_be16(&desc[4]);
277 	xop->dtdi = get_unaligned_be16(&desc[6]);
278 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
279 		desc_len, xop->stdi, xop->dtdi, dc);
280 
281 	xop->nolb = get_unaligned_be16(&desc[10]);
282 	xop->src_lba = get_unaligned_be64(&desc[12]);
283 	xop->dst_lba = get_unaligned_be64(&desc[20]);
284 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
285 		xop->nolb, (unsigned long long)xop->src_lba,
286 		(unsigned long long)xop->dst_lba);
287 
288 	if (dc != 0) {
289 		xop->dbl = (desc[29] & 0xff) << 16;
290 		xop->dbl |= (desc[30] & 0xff) << 8;
291 		xop->dbl |= desc[31] & 0xff;
292 
293 		pr_debug("XCOPY seg desc 0x02: DC=1 w/ dbl: %u\n", xop->dbl);
294 	}
295 	return 0;
296 }
297 
298 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
299 				struct xcopy_op *xop, unsigned char *p,
300 				unsigned int sdll)
301 {
302 	unsigned char *desc = p;
303 	unsigned int start = 0;
304 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
305 
306 	if (offset != 0) {
307 		pr_err("XCOPY segment descriptor list length is not"
308 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
309 		return -EINVAL;
310 	}
311 
312 	while (start < sdll) {
313 		/*
314 		 * Check segment descriptor type code for block -> block
315 		 */
316 		switch (desc[0]) {
317 		case 0x02:
318 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
319 			if (rc < 0)
320 				goto out;
321 
322 			ret++;
323 			start += XCOPY_SEGMENT_DESC_LEN;
324 			desc += XCOPY_SEGMENT_DESC_LEN;
325 			break;
326 		default:
327 			pr_err("XCOPY unsupported segment descriptor"
328 				"type: 0x%02x\n", desc[0]);
329 			goto out;
330 		}
331 	}
332 
333 	return ret;
334 
335 out:
336 	return -EINVAL;
337 }
338 
339 /*
340  * Start xcopy_pt ops
341  */
342 
343 struct xcopy_pt_cmd {
344 	bool remote_port;
345 	struct se_cmd se_cmd;
346 	struct xcopy_op *xcopy_op;
347 	struct completion xpt_passthrough_sem;
348 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
349 };
350 
351 static struct se_port xcopy_pt_port;
352 static struct se_portal_group xcopy_pt_tpg;
353 static struct se_session xcopy_pt_sess;
354 static struct se_node_acl xcopy_pt_nacl;
355 
356 static char *xcopy_pt_get_fabric_name(void)
357 {
358         return "xcopy-pt";
359 }
360 
361 static u32 xcopy_pt_get_tag(struct se_cmd *se_cmd)
362 {
363         return 0;
364 }
365 
366 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
367 {
368         return 0;
369 }
370 
371 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
372 {
373 	struct se_device *remote_dev;
374 
375 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
376 		remote_dev = xop->dst_dev;
377 	else
378 		remote_dev = xop->src_dev;
379 
380 	pr_debug("Calling configfs_undepend_item for"
381 		  " remote_dev: %p remote_dev->dev_group: %p\n",
382 		  remote_dev, &remote_dev->dev_group.cg_item);
383 
384 	target_undepend_item(&remote_dev->dev_group.cg_item);
385 }
386 
387 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
388 {
389 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
390 				struct xcopy_pt_cmd, se_cmd);
391 
392 	kfree(xpt_cmd);
393 }
394 
395 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
396 {
397 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
398 				struct xcopy_pt_cmd, se_cmd);
399 
400 	complete(&xpt_cmd->xpt_passthrough_sem);
401 	return 0;
402 }
403 
404 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
405 {
406 	return 0;
407 }
408 
409 static int xcopy_pt_write_pending_status(struct se_cmd *se_cmd)
410 {
411 	return 0;
412 }
413 
414 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
415 {
416 	return 0;
417 }
418 
419 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
420 {
421 	return 0;
422 }
423 
424 static const struct target_core_fabric_ops xcopy_pt_tfo = {
425 	.get_fabric_name	= xcopy_pt_get_fabric_name,
426 	.get_task_tag		= xcopy_pt_get_tag,
427 	.get_cmd_state		= xcopy_pt_get_cmd_state,
428 	.release_cmd		= xcopy_pt_release_cmd,
429 	.check_stop_free	= xcopy_pt_check_stop_free,
430 	.write_pending		= xcopy_pt_write_pending,
431 	.write_pending_status	= xcopy_pt_write_pending_status,
432 	.queue_data_in		= xcopy_pt_queue_data_in,
433 	.queue_status		= xcopy_pt_queue_status,
434 };
435 
436 /*
437  * End xcopy_pt_ops
438  */
439 
440 int target_xcopy_setup_pt(void)
441 {
442 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
443 	if (!xcopy_wq) {
444 		pr_err("Unable to allocate xcopy_wq\n");
445 		return -ENOMEM;
446 	}
447 
448 	memset(&xcopy_pt_port, 0, sizeof(struct se_port));
449 	INIT_LIST_HEAD(&xcopy_pt_port.sep_alua_list);
450 	INIT_LIST_HEAD(&xcopy_pt_port.sep_list);
451 	mutex_init(&xcopy_pt_port.sep_tg_pt_md_mutex);
452 
453 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
454 	INIT_LIST_HEAD(&xcopy_pt_tpg.se_tpg_node);
455 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
456 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
457 
458 	xcopy_pt_port.sep_tpg = &xcopy_pt_tpg;
459 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
460 
461 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
462 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
463 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
464 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
465 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_list);
466 	INIT_LIST_HEAD(&xcopy_pt_sess.sess_acl_list);
467 
468 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
469 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
470 
471 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
472 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
473 
474 	return 0;
475 }
476 
477 void target_xcopy_release_pt(void)
478 {
479 	if (xcopy_wq)
480 		destroy_workqueue(xcopy_wq);
481 }
482 
483 static void target_xcopy_setup_pt_port(
484 	struct xcopy_pt_cmd *xpt_cmd,
485 	struct xcopy_op *xop,
486 	bool remote_port)
487 {
488 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
489 	struct se_cmd *pt_cmd = &xpt_cmd->se_cmd;
490 
491 	if (xop->op_origin == XCOL_SOURCE_RECV_OP) {
492 		/*
493 		 * Honor destination port reservations for X-COPY PUSH emulation
494 		 * when CDB is received on local source port, and READs blocks to
495 		 * WRITE on remote destination port.
496 		 */
497 		if (remote_port) {
498 			xpt_cmd->remote_port = remote_port;
499 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
500 			pr_debug("Setup emulated remote DEST xcopy_pt_port: %p to"
501 				" cmd->se_lun->lun_sep for X-COPY data PUSH\n",
502 				pt_cmd->se_lun->lun_sep);
503 		} else {
504 			pt_cmd->se_lun = ec_cmd->se_lun;
505 			pt_cmd->se_dev = ec_cmd->se_dev;
506 
507 			pr_debug("Honoring local SRC port from ec_cmd->se_dev:"
508 				" %p\n", pt_cmd->se_dev);
509 			pt_cmd->se_lun = ec_cmd->se_lun;
510 			pr_debug("Honoring local SRC port from ec_cmd->se_lun: %p\n",
511 				pt_cmd->se_lun);
512 		}
513 	} else {
514 		/*
515 		 * Honor source port reservation for X-COPY PULL emulation
516 		 * when CDB is received on local desintation port, and READs
517 		 * blocks from the remote source port to WRITE on local
518 		 * destination port.
519 		 */
520 		if (remote_port) {
521 			xpt_cmd->remote_port = remote_port;
522 			pt_cmd->se_lun->lun_sep = &xcopy_pt_port;
523 			pr_debug("Setup emulated remote SRC xcopy_pt_port: %p to"
524 				" cmd->se_lun->lun_sep for X-COPY data PULL\n",
525 				pt_cmd->se_lun->lun_sep);
526 		} else {
527 			pt_cmd->se_lun = ec_cmd->se_lun;
528 			pt_cmd->se_dev = ec_cmd->se_dev;
529 
530 			pr_debug("Honoring local DST port from ec_cmd->se_dev:"
531 				" %p\n", pt_cmd->se_dev);
532 			pt_cmd->se_lun = ec_cmd->se_lun;
533 			pr_debug("Honoring local DST port from ec_cmd->se_lun: %p\n",
534 				pt_cmd->se_lun);
535 		}
536 	}
537 }
538 
539 static void target_xcopy_init_pt_lun(struct se_device *se_dev,
540 		struct se_cmd *pt_cmd, bool remote_port)
541 {
542 	/*
543 	 * Don't allocate + init an pt_cmd->se_lun if honoring local port for
544 	 * reservations.  The pt_cmd->se_lun pointer will be setup from within
545 	 * target_xcopy_setup_pt_port()
546 	 */
547 	if (remote_port) {
548 		pr_debug("Setup emulated se_dev: %p from se_dev\n",
549 			pt_cmd->se_dev);
550 		pt_cmd->se_lun = &se_dev->xcopy_lun;
551 		pt_cmd->se_dev = se_dev;
552 	}
553 
554 	pt_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
555 }
556 
557 static int target_xcopy_setup_pt_cmd(
558 	struct xcopy_pt_cmd *xpt_cmd,
559 	struct xcopy_op *xop,
560 	struct se_device *se_dev,
561 	unsigned char *cdb,
562 	bool remote_port,
563 	bool alloc_mem)
564 {
565 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
566 	sense_reason_t sense_rc;
567 	int ret = 0, rc;
568 	/*
569 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
570 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
571 	 */
572 	target_xcopy_init_pt_lun(se_dev, cmd, remote_port);
573 
574 	xpt_cmd->xcopy_op = xop;
575 	target_xcopy_setup_pt_port(xpt_cmd, xop, remote_port);
576 
577 	sense_rc = target_setup_cmd_from_cdb(cmd, cdb);
578 	if (sense_rc) {
579 		ret = -EINVAL;
580 		goto out;
581 	}
582 
583 	if (alloc_mem) {
584 		rc = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
585 				      cmd->data_length, false);
586 		if (rc < 0) {
587 			ret = rc;
588 			goto out;
589 		}
590 		/*
591 		 * Set this bit so that transport_free_pages() allows the
592 		 * caller to release SGLs + physical memory allocated by
593 		 * transport_generic_get_mem()..
594 		 */
595 		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
596 	} else {
597 		/*
598 		 * Here the previously allocated SGLs for the internal READ
599 		 * are mapped zero-copy to the internal WRITE.
600 		 */
601 		sense_rc = transport_generic_map_mem_to_cmd(cmd,
602 					xop->xop_data_sg, xop->xop_data_nents,
603 					NULL, 0);
604 		if (sense_rc) {
605 			ret = -EINVAL;
606 			goto out;
607 		}
608 
609 		pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
610 			 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
611 	}
612 
613 	return 0;
614 
615 out:
616 	return ret;
617 }
618 
619 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
620 {
621 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
622 	sense_reason_t sense_rc;
623 
624 	sense_rc = transport_generic_new_cmd(se_cmd);
625 	if (sense_rc)
626 		return -EINVAL;
627 
628 	if (se_cmd->data_direction == DMA_TO_DEVICE)
629 		target_execute_cmd(se_cmd);
630 
631 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
632 
633 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
634 			se_cmd->scsi_status);
635 
636 	return (se_cmd->scsi_status) ? -EINVAL : 0;
637 }
638 
639 static int target_xcopy_read_source(
640 	struct se_cmd *ec_cmd,
641 	struct xcopy_op *xop,
642 	struct se_device *src_dev,
643 	sector_t src_lba,
644 	u32 src_sectors)
645 {
646 	struct xcopy_pt_cmd *xpt_cmd;
647 	struct se_cmd *se_cmd;
648 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
649 	int rc;
650 	unsigned char cdb[16];
651 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
652 
653 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
654 	if (!xpt_cmd) {
655 		pr_err("Unable to allocate xcopy_pt_cmd\n");
656 		return -ENOMEM;
657 	}
658 	init_completion(&xpt_cmd->xpt_passthrough_sem);
659 	se_cmd = &xpt_cmd->se_cmd;
660 
661 	memset(&cdb[0], 0, 16);
662 	cdb[0] = READ_16;
663 	put_unaligned_be64(src_lba, &cdb[2]);
664 	put_unaligned_be32(src_sectors, &cdb[10]);
665 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
666 		(unsigned long long)src_lba, src_sectors, length);
667 
668 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
669 			      DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
670 	xop->src_pt_cmd = xpt_cmd;
671 
672 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
673 				remote_port, true);
674 	if (rc < 0) {
675 		transport_generic_free_cmd(se_cmd, 0);
676 		return rc;
677 	}
678 
679 	xop->xop_data_sg = se_cmd->t_data_sg;
680 	xop->xop_data_nents = se_cmd->t_data_nents;
681 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
682 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
683 
684 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
685 	if (rc < 0) {
686 		transport_generic_free_cmd(se_cmd, 0);
687 		return rc;
688 	}
689 	/*
690 	 * Clear off the allocated t_data_sg, that has been saved for
691 	 * zero-copy WRITE submission reuse in struct xcopy_op..
692 	 */
693 	se_cmd->t_data_sg = NULL;
694 	se_cmd->t_data_nents = 0;
695 
696 	return 0;
697 }
698 
699 static int target_xcopy_write_destination(
700 	struct se_cmd *ec_cmd,
701 	struct xcopy_op *xop,
702 	struct se_device *dst_dev,
703 	sector_t dst_lba,
704 	u32 dst_sectors)
705 {
706 	struct xcopy_pt_cmd *xpt_cmd;
707 	struct se_cmd *se_cmd;
708 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
709 	int rc;
710 	unsigned char cdb[16];
711 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
712 
713 	xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
714 	if (!xpt_cmd) {
715 		pr_err("Unable to allocate xcopy_pt_cmd\n");
716 		return -ENOMEM;
717 	}
718 	init_completion(&xpt_cmd->xpt_passthrough_sem);
719 	se_cmd = &xpt_cmd->se_cmd;
720 
721 	memset(&cdb[0], 0, 16);
722 	cdb[0] = WRITE_16;
723 	put_unaligned_be64(dst_lba, &cdb[2]);
724 	put_unaligned_be32(dst_sectors, &cdb[10]);
725 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
726 		(unsigned long long)dst_lba, dst_sectors, length);
727 
728 	transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, NULL, length,
729 			      DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
730 	xop->dst_pt_cmd = xpt_cmd;
731 
732 	rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
733 				remote_port, false);
734 	if (rc < 0) {
735 		struct se_cmd *src_cmd = &xop->src_pt_cmd->se_cmd;
736 		/*
737 		 * If the failure happened before the t_mem_list hand-off in
738 		 * target_xcopy_setup_pt_cmd(), Reset memory + clear flag so that
739 		 * core releases this memory on error during X-COPY WRITE I/O.
740 		 */
741 		src_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
742 		src_cmd->t_data_sg = xop->xop_data_sg;
743 		src_cmd->t_data_nents = xop->xop_data_nents;
744 
745 		transport_generic_free_cmd(se_cmd, 0);
746 		return rc;
747 	}
748 
749 	rc = target_xcopy_issue_pt_cmd(xpt_cmd);
750 	if (rc < 0) {
751 		se_cmd->se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
752 		transport_generic_free_cmd(se_cmd, 0);
753 		return rc;
754 	}
755 
756 	return 0;
757 }
758 
759 static void target_xcopy_do_work(struct work_struct *work)
760 {
761 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
762 	struct se_device *src_dev = xop->src_dev, *dst_dev = xop->dst_dev;
763 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
764 	sector_t src_lba = xop->src_lba, dst_lba = xop->dst_lba, end_lba;
765 	unsigned int max_sectors;
766 	int rc;
767 	unsigned short nolb = xop->nolb, cur_nolb, max_nolb, copied_nolb = 0;
768 
769 	end_lba = src_lba + nolb;
770 	/*
771 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
772 	 * smallest max_sectors between src_dev + dev_dev, or
773 	 */
774 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
775 			  dst_dev->dev_attrib.hw_max_sectors);
776 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
777 
778 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
779 
780 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
781 			nolb, max_nolb, (unsigned long long)end_lba);
782 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
783 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
784 
785 	while (src_lba < end_lba) {
786 		cur_nolb = min(nolb, max_nolb);
787 
788 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
789 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
790 
791 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
792 		if (rc < 0)
793 			goto out;
794 
795 		src_lba += cur_nolb;
796 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
797 				(unsigned long long)src_lba);
798 
799 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
800 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
801 
802 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
803 						dst_lba, cur_nolb);
804 		if (rc < 0) {
805 			transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
806 			goto out;
807 		}
808 
809 		dst_lba += cur_nolb;
810 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
811 				(unsigned long long)dst_lba);
812 
813 		copied_nolb += cur_nolb;
814 		nolb -= cur_nolb;
815 
816 		transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
817 		xop->dst_pt_cmd->se_cmd.se_cmd_flags &= ~SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
818 
819 		transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
820 	}
821 
822 	xcopy_pt_undepend_remotedev(xop);
823 	kfree(xop);
824 
825 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
826 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
827 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
828 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
829 
830 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
831 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
832 	return;
833 
834 out:
835 	xcopy_pt_undepend_remotedev(xop);
836 	kfree(xop);
837 
838 	pr_warn("target_xcopy_do_work: Setting X-COPY CHECK_CONDITION -> sending response\n");
839 	ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
840 	target_complete_cmd(ec_cmd, SAM_STAT_CHECK_CONDITION);
841 }
842 
843 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
844 {
845 	struct se_device *dev = se_cmd->se_dev;
846 	struct xcopy_op *xop = NULL;
847 	unsigned char *p = NULL, *seg_desc;
848 	unsigned int list_id, list_id_usage, sdll, inline_dl, sa;
849 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
850 	int rc;
851 	unsigned short tdll;
852 
853 	if (!dev->dev_attrib.emulate_3pc) {
854 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
855 		return TCM_UNSUPPORTED_SCSI_OPCODE;
856 	}
857 
858 	sa = se_cmd->t_task_cdb[1] & 0x1f;
859 	if (sa != 0x00) {
860 		pr_err("EXTENDED_COPY(LID4) not supported\n");
861 		return TCM_UNSUPPORTED_SCSI_OPCODE;
862 	}
863 
864 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
865 	if (!xop) {
866 		pr_err("Unable to allocate xcopy_op\n");
867 		return TCM_OUT_OF_RESOURCES;
868 	}
869 	xop->xop_se_cmd = se_cmd;
870 
871 	p = transport_kmap_data_sg(se_cmd);
872 	if (!p) {
873 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
874 		kfree(xop);
875 		return TCM_OUT_OF_RESOURCES;
876 	}
877 
878 	list_id = p[0];
879 	list_id_usage = (p[1] & 0x18) >> 3;
880 
881 	/*
882 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
883 	 */
884 	tdll = get_unaligned_be16(&p[2]);
885 	sdll = get_unaligned_be32(&p[8]);
886 
887 	inline_dl = get_unaligned_be32(&p[12]);
888 	if (inline_dl != 0) {
889 		pr_err("XCOPY with non zero inline data length\n");
890 		goto out;
891 	}
892 
893 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
894 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
895 		tdll, sdll, inline_dl);
896 
897 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll);
898 	if (rc <= 0)
899 		goto out;
900 
901 	if (xop->src_dev->dev_attrib.block_size !=
902 	    xop->dst_dev->dev_attrib.block_size) {
903 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
904 		       " block_size: %u currently unsupported\n",
905 			xop->src_dev->dev_attrib.block_size,
906 			xop->dst_dev->dev_attrib.block_size);
907 		xcopy_pt_undepend_remotedev(xop);
908 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
909 		goto out;
910 	}
911 
912 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
913 				rc * XCOPY_TARGET_DESC_LEN);
914 	seg_desc = &p[16];
915 	seg_desc += (rc * XCOPY_TARGET_DESC_LEN);
916 
917 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc, sdll);
918 	if (rc <= 0) {
919 		xcopy_pt_undepend_remotedev(xop);
920 		goto out;
921 	}
922 	transport_kunmap_data_sg(se_cmd);
923 
924 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
925 				rc * XCOPY_SEGMENT_DESC_LEN);
926 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
927 	queue_work(xcopy_wq, &xop->xop_work);
928 	return TCM_NO_SENSE;
929 
930 out:
931 	if (p)
932 		transport_kunmap_data_sg(se_cmd);
933 	kfree(xop);
934 	return ret;
935 }
936 
937 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
938 {
939 	unsigned char *p;
940 
941 	p = transport_kmap_data_sg(se_cmd);
942 	if (!p) {
943 		pr_err("transport_kmap_data_sg failed in"
944 		       " target_rcr_operating_parameters\n");
945 		return TCM_OUT_OF_RESOURCES;
946 	}
947 
948 	if (se_cmd->data_length < 54) {
949 		pr_err("Receive Copy Results Op Parameters length"
950 		       " too small: %u\n", se_cmd->data_length);
951 		transport_kunmap_data_sg(se_cmd);
952 		return TCM_INVALID_CDB_FIELD;
953 	}
954 	/*
955 	 * Set SNLID=1 (Supports no List ID)
956 	 */
957 	p[4] = 0x1;
958 	/*
959 	 * MAXIMUM TARGET DESCRIPTOR COUNT
960 	 */
961 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
962 	/*
963 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
964 	 */
965 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
966 	/*
967 	 * MAXIMUM DESCRIPTOR LIST LENGTH
968 	 */
969 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
970 	/*
971 	 * MAXIMUM SEGMENT LENGTH
972 	 */
973 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
974 	/*
975 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
976 	 */
977 	put_unaligned_be32(0x0, &p[20]);
978 	/*
979 	 * HELD DATA LIMIT
980 	 */
981 	put_unaligned_be32(0x0, &p[24]);
982 	/*
983 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
984 	 */
985 	put_unaligned_be32(0x0, &p[28]);
986 	/*
987 	 * TOTAL CONCURRENT COPIES
988 	 */
989 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
990 	/*
991 	 * MAXIMUM CONCURRENT COPIES
992 	 */
993 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
994 	/*
995 	 * DATA SEGMENT GRANULARITY (log 2)
996 	 */
997 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
998 	/*
999 	 * INLINE DATA GRANULARITY log 2)
1000 	 */
1001 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
1002 	/*
1003 	 * HELD DATA GRANULARITY
1004 	 */
1005 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
1006 	/*
1007 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
1008 	 */
1009 	p[43] = 0x2;
1010 	/*
1011 	 * List of implemented descriptor type codes (ordered)
1012 	 */
1013 	p[44] = 0x02; /* Copy Block to Block device */
1014 	p[45] = 0xe4; /* Identification descriptor target descriptor */
1015 
1016 	/*
1017 	 * AVAILABLE DATA (n-3)
1018 	 */
1019 	put_unaligned_be32(42, &p[0]);
1020 
1021 	transport_kunmap_data_sg(se_cmd);
1022 	target_complete_cmd(se_cmd, GOOD);
1023 
1024 	return TCM_NO_SENSE;
1025 }
1026 
1027 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1028 {
1029 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1030 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1031 	sense_reason_t rc = TCM_NO_SENSE;
1032 
1033 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1034 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1035 
1036 	if (list_id != 0) {
1037 		pr_err("Receive Copy Results with non zero list identifier"
1038 		       " not supported\n");
1039 		return TCM_INVALID_CDB_FIELD;
1040 	}
1041 
1042 	switch (sa) {
1043 	case RCR_SA_OPERATING_PARAMETERS:
1044 		rc = target_rcr_operating_parameters(se_cmd);
1045 		break;
1046 	case RCR_SA_COPY_STATUS:
1047 	case RCR_SA_RECEIVE_DATA:
1048 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1049 	default:
1050 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1051 		return TCM_INVALID_CDB_FIELD;
1052 	}
1053 
1054 	return rc;
1055 }
1056