1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename: target_core_xcopy.c
4  *
5  * This file contains support for SPC-4 Extended-Copy offload with generic
6  * TCM backends.
7  *
8  * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
9  *
10  * Author:
11  * Nicholas A. Bellinger <nab@daterainc.com>
12  *
13  ******************************************************************************/
14 
15 #include <linux/slab.h>
16 #include <linux/spinlock.h>
17 #include <linux/list.h>
18 #include <linux/configfs.h>
19 #include <linux/ratelimit.h>
20 #include <scsi/scsi_proto.h>
21 #include <asm/unaligned.h>
22 
23 #include <target/target_core_base.h>
24 #include <target/target_core_backend.h>
25 #include <target/target_core_fabric.h>
26 
27 #include "target_core_internal.h"
28 #include "target_core_pr.h"
29 #include "target_core_ua.h"
30 #include "target_core_xcopy.h"
31 
32 static struct workqueue_struct *xcopy_wq = NULL;
33 
34 static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop);
35 
36 /**
37  * target_xcopy_locate_se_dev_e4_iter - compare XCOPY NAA device identifiers
38  *
39  * @se_dev: device being considered for match
40  * @dev_wwn: XCOPY requested NAA dev_wwn
41  * @return: 1 on match, 0 on no-match
42  */
43 static int target_xcopy_locate_se_dev_e4_iter(struct se_device *se_dev,
44 					      const unsigned char *dev_wwn)
45 {
46 	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN];
47 	int rc;
48 
49 	if (!se_dev->dev_attrib.emulate_3pc) {
50 		pr_debug("XCOPY: emulate_3pc disabled on se_dev %p\n", se_dev);
51 		return 0;
52 	}
53 
54 	memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
55 	spc_gen_naa_6h_vendor_specific(se_dev, &tmp_dev_wwn[0]);
56 
57 	rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
58 	if (rc != 0) {
59 		pr_debug("XCOPY: skip non-matching: %*ph\n",
60 			 XCOPY_NAA_IEEE_REGEX_LEN, tmp_dev_wwn);
61 		return 0;
62 	}
63 	pr_debug("XCOPY 0xe4: located se_dev: %p\n", se_dev);
64 
65 	return 1;
66 }
67 
68 static int target_xcopy_locate_se_dev_e4(struct se_session *sess,
69 					const unsigned char *dev_wwn,
70 					struct se_device **_found_dev,
71 					struct percpu_ref **_found_lun_ref)
72 {
73 	struct se_dev_entry *deve;
74 	struct se_node_acl *nacl;
75 	struct se_lun *this_lun = NULL;
76 	struct se_device *found_dev = NULL;
77 
78 	/* cmd with NULL sess indicates no associated $FABRIC_MOD */
79 	if (!sess)
80 		goto err_out;
81 
82 	pr_debug("XCOPY 0xe4: searching for: %*ph\n",
83 		 XCOPY_NAA_IEEE_REGEX_LEN, dev_wwn);
84 
85 	nacl = sess->se_node_acl;
86 	rcu_read_lock();
87 	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
88 		struct se_device *this_dev;
89 		int rc;
90 
91 		this_lun = deve->se_lun;
92 		this_dev = rcu_dereference_raw(this_lun->lun_se_dev);
93 
94 		rc = target_xcopy_locate_se_dev_e4_iter(this_dev, dev_wwn);
95 		if (rc) {
96 			if (percpu_ref_tryget_live(&this_lun->lun_ref))
97 				found_dev = this_dev;
98 			break;
99 		}
100 	}
101 	rcu_read_unlock();
102 	if (found_dev == NULL)
103 		goto err_out;
104 
105 	pr_debug("lun_ref held for se_dev: %p se_dev->se_dev_group: %p\n",
106 		 found_dev, &found_dev->dev_group);
107 	*_found_dev = found_dev;
108 	*_found_lun_ref = &this_lun->lun_ref;
109 	return 0;
110 err_out:
111 	pr_debug_ratelimited("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
112 	return -EINVAL;
113 }
114 
115 static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
116 				unsigned char *p, unsigned short cscd_index)
117 {
118 	unsigned char *desc = p;
119 	unsigned short ript;
120 	u8 desig_len;
121 	/*
122 	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
123 	 */
124 	ript = get_unaligned_be16(&desc[2]);
125 	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
126 	/*
127 	 * Check for supported code set, association, and designator type
128 	 */
129 	if ((desc[4] & 0x0f) != 0x1) {
130 		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
131 		return -EINVAL;
132 	}
133 	if ((desc[5] & 0x30) != 0x00) {
134 		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
135 		return -EINVAL;
136 	}
137 	if ((desc[5] & 0x0f) != 0x3) {
138 		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
139 				(desc[5] & 0x0f));
140 		return -EINVAL;
141 	}
142 	/*
143 	 * Check for matching 16 byte length for NAA IEEE Registered Extended
144 	 * Assigned designator
145 	 */
146 	desig_len = desc[7];
147 	if (desig_len != XCOPY_NAA_IEEE_REGEX_LEN) {
148 		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
149 		return -EINVAL;
150 	}
151 	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
152 	/*
153 	 * Check for NAA IEEE Registered Extended Assigned header..
154 	 */
155 	if ((desc[8] & 0xf0) != 0x60) {
156 		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
157 					(desc[8] & 0xf0));
158 		return -EINVAL;
159 	}
160 
161 	if (cscd_index != xop->stdi && cscd_index != xop->dtdi) {
162 		pr_debug("XCOPY 0xe4: ignoring CSCD entry %d - neither src nor "
163 			 "dest\n", cscd_index);
164 		return 0;
165 	}
166 
167 	if (cscd_index == xop->stdi) {
168 		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
169 		/*
170 		 * Determine if the source designator matches the local device
171 		 */
172 		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
173 				XCOPY_NAA_IEEE_REGEX_LEN)) {
174 			xop->op_origin = XCOL_SOURCE_RECV_OP;
175 			xop->src_dev = se_cmd->se_dev;
176 			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
177 					" received xop\n", xop->src_dev);
178 		}
179 	}
180 
181 	if (cscd_index == xop->dtdi) {
182 		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
183 		/*
184 		 * Determine if the destination designator matches the local
185 		 * device. If @cscd_index corresponds to both source (stdi) and
186 		 * destination (dtdi), or dtdi comes after stdi, then
187 		 * XCOL_DEST_RECV_OP wins.
188 		 */
189 		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
190 				XCOPY_NAA_IEEE_REGEX_LEN)) {
191 			xop->op_origin = XCOL_DEST_RECV_OP;
192 			xop->dst_dev = se_cmd->se_dev;
193 			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
194 				" received xop\n", xop->dst_dev);
195 		}
196 	}
197 
198 	return 0;
199 }
200 
201 static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
202 				struct xcopy_op *xop, unsigned char *p,
203 				unsigned short tdll, sense_reason_t *sense_ret)
204 {
205 	struct se_device *local_dev = se_cmd->se_dev;
206 	unsigned char *desc = p;
207 	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc;
208 	unsigned short cscd_index = 0;
209 	unsigned short start = 0;
210 
211 	*sense_ret = TCM_INVALID_PARAMETER_LIST;
212 
213 	if (offset != 0) {
214 		pr_err("XCOPY target descriptor list length is not"
215 			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
216 		*sense_ret = TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE;
217 		return -EINVAL;
218 	}
219 	if (tdll > RCR_OP_MAX_TARGET_DESC_COUNT * XCOPY_TARGET_DESC_LEN) {
220 		pr_err("XCOPY target descriptor supports a maximum"
221 			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
222 		/* spc4r37 6.4.3.4 CSCD DESCRIPTOR LIST LENGTH field */
223 		*sense_ret = TCM_TOO_MANY_TARGET_DESCS;
224 		return -EINVAL;
225 	}
226 	/*
227 	 * Generate an IEEE Registered Extended designator based upon the
228 	 * se_device the XCOPY was received upon..
229 	 */
230 	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
231 	spc_gen_naa_6h_vendor_specific(local_dev, &xop->local_dev_wwn[0]);
232 
233 	while (start < tdll) {
234 		/*
235 		 * Check target descriptor identification with 0xE4 type, and
236 		 * compare the current index with the CSCD descriptor IDs in
237 		 * the segment descriptor. Use VPD 0x83 WWPN matching ..
238 		 */
239 		switch (desc[0]) {
240 		case 0xe4:
241 			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
242 							&desc[0], cscd_index);
243 			if (rc != 0)
244 				goto out;
245 			start += XCOPY_TARGET_DESC_LEN;
246 			desc += XCOPY_TARGET_DESC_LEN;
247 			cscd_index++;
248 			break;
249 		default:
250 			pr_err("XCOPY unsupported descriptor type code:"
251 					" 0x%02x\n", desc[0]);
252 			*sense_ret = TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE;
253 			goto out;
254 		}
255 	}
256 
257 	switch (xop->op_origin) {
258 	case XCOL_SOURCE_RECV_OP:
259 		rc = target_xcopy_locate_se_dev_e4(se_cmd->se_sess,
260 						xop->dst_tid_wwn,
261 						&xop->dst_dev,
262 						&xop->remote_lun_ref);
263 		break;
264 	case XCOL_DEST_RECV_OP:
265 		rc = target_xcopy_locate_se_dev_e4(se_cmd->se_sess,
266 						xop->src_tid_wwn,
267 						&xop->src_dev,
268 						&xop->remote_lun_ref);
269 		break;
270 	default:
271 		pr_err("XCOPY CSCD descriptor IDs not found in CSCD list - "
272 			"stdi: %hu dtdi: %hu\n", xop->stdi, xop->dtdi);
273 		rc = -EINVAL;
274 		break;
275 	}
276 	/*
277 	 * If a matching IEEE NAA 0x83 descriptor for the requested device
278 	 * is not located on this node, return COPY_ABORTED with ASQ/ASQC
279 	 * 0x0d/0x02 - COPY_TARGET_DEVICE_NOT_REACHABLE to request the
280 	 * initiator to fall back to normal copy method.
281 	 */
282 	if (rc < 0) {
283 		*sense_ret = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
284 		goto out;
285 	}
286 
287 	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
288 		 xop->src_dev, &xop->src_tid_wwn[0]);
289 	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
290 		 xop->dst_dev, &xop->dst_tid_wwn[0]);
291 
292 	return cscd_index;
293 
294 out:
295 	return -EINVAL;
296 }
297 
298 static int target_xcopy_parse_segdesc_02(struct xcopy_op *xop, unsigned char *p)
299 {
300 	unsigned char *desc = p;
301 	int dc = (desc[1] & 0x02);
302 	unsigned short desc_len;
303 
304 	desc_len = get_unaligned_be16(&desc[2]);
305 	if (desc_len != 0x18) {
306 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
307 				" %hu\n", desc_len);
308 		return -EINVAL;
309 	}
310 
311 	xop->stdi = get_unaligned_be16(&desc[4]);
312 	xop->dtdi = get_unaligned_be16(&desc[6]);
313 
314 	if (xop->stdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX ||
315 	    xop->dtdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX) {
316 		pr_err("XCOPY segment desc 0x02: unsupported CSCD ID > 0x%x; stdi: %hu dtdi: %hu\n",
317 			XCOPY_CSCD_DESC_ID_LIST_OFF_MAX, xop->stdi, xop->dtdi);
318 		return -EINVAL;
319 	}
320 
321 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
322 		desc_len, xop->stdi, xop->dtdi, dc);
323 
324 	xop->nolb = get_unaligned_be16(&desc[10]);
325 	xop->src_lba = get_unaligned_be64(&desc[12]);
326 	xop->dst_lba = get_unaligned_be64(&desc[20]);
327 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
328 		xop->nolb, (unsigned long long)xop->src_lba,
329 		(unsigned long long)xop->dst_lba);
330 
331 	return 0;
332 }
333 
334 static int target_xcopy_parse_segment_descriptors(struct xcopy_op *xop,
335 				unsigned char *p, unsigned int sdll,
336 				sense_reason_t *sense_ret)
337 {
338 	unsigned char *desc = p;
339 	unsigned int start = 0;
340 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
341 
342 	*sense_ret = TCM_INVALID_PARAMETER_LIST;
343 
344 	if (offset != 0) {
345 		pr_err("XCOPY segment descriptor list length is not"
346 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
347 		*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
348 		return -EINVAL;
349 	}
350 	if (sdll > RCR_OP_MAX_SG_DESC_COUNT * XCOPY_SEGMENT_DESC_LEN) {
351 		pr_err("XCOPY supports %u segment descriptor(s), sdll: %u too"
352 			" large..\n", RCR_OP_MAX_SG_DESC_COUNT, sdll);
353 		/* spc4r37 6.4.3.5 SEGMENT DESCRIPTOR LIST LENGTH field */
354 		*sense_ret = TCM_TOO_MANY_SEGMENT_DESCS;
355 		return -EINVAL;
356 	}
357 
358 	while (start < sdll) {
359 		/*
360 		 * Check segment descriptor type code for block -> block
361 		 */
362 		switch (desc[0]) {
363 		case 0x02:
364 			rc = target_xcopy_parse_segdesc_02(xop, desc);
365 			if (rc < 0)
366 				goto out;
367 
368 			ret++;
369 			start += XCOPY_SEGMENT_DESC_LEN;
370 			desc += XCOPY_SEGMENT_DESC_LEN;
371 			break;
372 		default:
373 			pr_err("XCOPY unsupported segment descriptor"
374 				"type: 0x%02x\n", desc[0]);
375 			*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
376 			goto out;
377 		}
378 	}
379 
380 	return ret;
381 
382 out:
383 	return -EINVAL;
384 }
385 
386 /*
387  * Start xcopy_pt ops
388  */
389 
390 struct xcopy_pt_cmd {
391 	struct se_cmd se_cmd;
392 	struct completion xpt_passthrough_sem;
393 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
394 };
395 
396 struct se_portal_group xcopy_pt_tpg;
397 static struct se_session xcopy_pt_sess;
398 static struct se_node_acl xcopy_pt_nacl;
399 
400 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
401 {
402         return 0;
403 }
404 
405 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
406 {
407 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
408 		pr_debug("putting dst lun_ref for %p\n", xop->dst_dev);
409 	else
410 		pr_debug("putting src lun_ref for %p\n", xop->src_dev);
411 
412 	percpu_ref_put(xop->remote_lun_ref);
413 }
414 
415 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
416 {
417 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
418 				struct xcopy_pt_cmd, se_cmd);
419 
420 	/* xpt_cmd is on the stack, nothing to free here */
421 	pr_debug("xpt_cmd done: %p\n", xpt_cmd);
422 }
423 
424 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
425 {
426 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
427 				struct xcopy_pt_cmd, se_cmd);
428 
429 	complete(&xpt_cmd->xpt_passthrough_sem);
430 	return 0;
431 }
432 
433 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
434 {
435 	return 0;
436 }
437 
438 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
439 {
440 	return 0;
441 }
442 
443 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
444 {
445 	return 0;
446 }
447 
448 static const struct target_core_fabric_ops xcopy_pt_tfo = {
449 	.fabric_name		= "xcopy-pt",
450 	.get_cmd_state		= xcopy_pt_get_cmd_state,
451 	.release_cmd		= xcopy_pt_release_cmd,
452 	.check_stop_free	= xcopy_pt_check_stop_free,
453 	.write_pending		= xcopy_pt_write_pending,
454 	.queue_data_in		= xcopy_pt_queue_data_in,
455 	.queue_status		= xcopy_pt_queue_status,
456 };
457 
458 /*
459  * End xcopy_pt_ops
460  */
461 
462 int target_xcopy_setup_pt(void)
463 {
464 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
465 	if (!xcopy_wq) {
466 		pr_err("Unable to allocate xcopy_wq\n");
467 		return -ENOMEM;
468 	}
469 
470 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
471 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
472 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
473 
474 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
475 
476 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
477 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
478 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
479 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
480 	transport_init_session(&xcopy_pt_sess);
481 
482 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
483 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
484 
485 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
486 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
487 
488 	return 0;
489 }
490 
491 void target_xcopy_release_pt(void)
492 {
493 	if (xcopy_wq)
494 		destroy_workqueue(xcopy_wq);
495 }
496 
497 /*
498  * target_xcopy_setup_pt_cmd - set up a pass-through command
499  * @xpt_cmd:	 Data structure to initialize.
500  * @xop:	 Describes the XCOPY operation received from an initiator.
501  * @se_dev:	 Backend device to associate with @xpt_cmd if
502  *		 @remote_port == true.
503  * @cdb:	 SCSI CDB to be copied into @xpt_cmd.
504  * @remote_port: If false, use the LUN through which the XCOPY command has
505  *		 been received. If true, use @se_dev->xcopy_lun.
506  *
507  * Set up a SCSI command (READ or WRITE) that will be used to execute an
508  * XCOPY command.
509  */
510 static int target_xcopy_setup_pt_cmd(
511 	struct xcopy_pt_cmd *xpt_cmd,
512 	struct xcopy_op *xop,
513 	struct se_device *se_dev,
514 	unsigned char *cdb,
515 	bool remote_port)
516 {
517 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
518 
519 	/*
520 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
521 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
522 	 */
523 	if (remote_port) {
524 		cmd->se_lun = &se_dev->xcopy_lun;
525 		cmd->se_dev = se_dev;
526 	} else {
527 		cmd->se_lun = xop->xop_se_cmd->se_lun;
528 		cmd->se_dev = xop->xop_se_cmd->se_dev;
529 	}
530 	cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
531 
532 	if (target_cmd_init_cdb(cmd, cdb, GFP_KERNEL))
533 		return -EINVAL;
534 
535 	cmd->tag = 0;
536 	if (target_cmd_parse_cdb(cmd))
537 		return -EINVAL;
538 
539 	if (transport_generic_map_mem_to_cmd(cmd, xop->xop_data_sg,
540 					xop->xop_data_nents, NULL, 0))
541 		return -EINVAL;
542 
543 	pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
544 		 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
545 
546 	return 0;
547 }
548 
549 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
550 {
551 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
552 	sense_reason_t sense_rc;
553 
554 	sense_rc = transport_generic_new_cmd(se_cmd);
555 	if (sense_rc)
556 		return -EINVAL;
557 
558 	if (se_cmd->data_direction == DMA_TO_DEVICE)
559 		target_execute_cmd(se_cmd);
560 
561 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
562 
563 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
564 			se_cmd->scsi_status);
565 
566 	return (se_cmd->scsi_status) ? -EINVAL : 0;
567 }
568 
569 static int target_xcopy_read_source(
570 	struct se_cmd *ec_cmd,
571 	struct xcopy_op *xop,
572 	struct se_device *src_dev,
573 	sector_t src_lba,
574 	u32 src_bytes)
575 {
576 	struct xcopy_pt_cmd xpt_cmd;
577 	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
578 	u32 transfer_length_block = src_bytes / src_dev->dev_attrib.block_size;
579 	int rc;
580 	unsigned char cdb[16];
581 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
582 
583 	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
584 	init_completion(&xpt_cmd.xpt_passthrough_sem);
585 
586 	memset(&cdb[0], 0, 16);
587 	cdb[0] = READ_16;
588 	put_unaligned_be64(src_lba, &cdb[2]);
589 	put_unaligned_be32(transfer_length_block, &cdb[10]);
590 	pr_debug("XCOPY: Built READ_16: LBA: %llu Blocks: %u Length: %u\n",
591 		(unsigned long long)src_lba, transfer_length_block, src_bytes);
592 
593 	__target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, src_bytes,
594 			  DMA_FROM_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0,
595 			  NULL);
596 	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, src_dev, &cdb[0],
597 				remote_port);
598 	if (rc < 0) {
599 		ec_cmd->scsi_status = se_cmd->scsi_status;
600 		goto out;
601 	}
602 
603 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
604 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
605 
606 	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
607 	if (rc < 0)
608 		ec_cmd->scsi_status = se_cmd->scsi_status;
609 out:
610 	transport_generic_free_cmd(se_cmd, 0);
611 	return rc;
612 }
613 
614 static int target_xcopy_write_destination(
615 	struct se_cmd *ec_cmd,
616 	struct xcopy_op *xop,
617 	struct se_device *dst_dev,
618 	sector_t dst_lba,
619 	u32 dst_bytes)
620 {
621 	struct xcopy_pt_cmd xpt_cmd;
622 	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
623 	u32 transfer_length_block = dst_bytes / dst_dev->dev_attrib.block_size;
624 	int rc;
625 	unsigned char cdb[16];
626 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
627 
628 	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
629 	init_completion(&xpt_cmd.xpt_passthrough_sem);
630 
631 	memset(&cdb[0], 0, 16);
632 	cdb[0] = WRITE_16;
633 	put_unaligned_be64(dst_lba, &cdb[2]);
634 	put_unaligned_be32(transfer_length_block, &cdb[10]);
635 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Blocks: %u Length: %u\n",
636 		(unsigned long long)dst_lba, transfer_length_block, dst_bytes);
637 
638 	__target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, dst_bytes,
639 			  DMA_TO_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0,
640 			  NULL);
641 	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, dst_dev, &cdb[0],
642 				remote_port);
643 	if (rc < 0) {
644 		ec_cmd->scsi_status = se_cmd->scsi_status;
645 		goto out;
646 	}
647 
648 	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
649 	if (rc < 0)
650 		ec_cmd->scsi_status = se_cmd->scsi_status;
651 out:
652 	transport_generic_free_cmd(se_cmd, 0);
653 	return rc;
654 }
655 
656 static void target_xcopy_do_work(struct work_struct *work)
657 {
658 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
659 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
660 	struct se_device *src_dev, *dst_dev;
661 	sector_t src_lba, dst_lba, end_lba;
662 	unsigned long long max_bytes, max_bytes_src, max_bytes_dst, max_blocks;
663 	int rc = 0;
664 	unsigned short nolb;
665 	unsigned int copied_bytes = 0;
666 	sense_reason_t sense_rc;
667 
668 	sense_rc = target_parse_xcopy_cmd(xop);
669 	if (sense_rc != TCM_NO_SENSE)
670 		goto err_free;
671 
672 	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev)) {
673 		sense_rc = TCM_INVALID_PARAMETER_LIST;
674 		goto err_free;
675 	}
676 
677 	src_dev = xop->src_dev;
678 	dst_dev = xop->dst_dev;
679 	src_lba = xop->src_lba;
680 	dst_lba = xop->dst_lba;
681 	nolb = xop->nolb;
682 	end_lba = src_lba + nolb;
683 	/*
684 	 * Break up XCOPY I/O into hw_max_sectors * hw_block_size sized
685 	 * I/O based on the smallest max_bytes between src_dev + dst_dev
686 	 */
687 	max_bytes_src = (unsigned long long) src_dev->dev_attrib.hw_max_sectors *
688 			src_dev->dev_attrib.hw_block_size;
689 	max_bytes_dst = (unsigned long long) dst_dev->dev_attrib.hw_max_sectors *
690 			dst_dev->dev_attrib.hw_block_size;
691 
692 	max_bytes = min_t(u64, max_bytes_src, max_bytes_dst);
693 	max_bytes = min_t(u64, max_bytes, XCOPY_MAX_BYTES);
694 
695 	/*
696 	 * Using shift instead of the division because otherwise GCC
697 	 * generates __udivdi3 that is missing on i386
698 	 */
699 	max_blocks = max_bytes >> ilog2(src_dev->dev_attrib.block_size);
700 
701 	pr_debug("%s: nolb: %u, max_blocks: %llu end_lba: %llu\n", __func__,
702 			nolb, max_blocks, (unsigned long long)end_lba);
703 	pr_debug("%s: Starting src_lba: %llu, dst_lba: %llu\n", __func__,
704 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
705 
706 	while (nolb) {
707 		u32 cur_bytes = min_t(u64, max_bytes, nolb * src_dev->dev_attrib.block_size);
708 		unsigned short cur_nolb = cur_bytes / src_dev->dev_attrib.block_size;
709 
710 		if (cur_bytes != xop->xop_data_bytes) {
711 			/*
712 			 * (Re)allocate a buffer large enough to hold the XCOPY
713 			 * I/O size, which can be reused each read / write loop.
714 			 */
715 			target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
716 			rc = target_alloc_sgl(&xop->xop_data_sg,
717 					      &xop->xop_data_nents,
718 					      cur_bytes,
719 					      false, false);
720 			if (rc < 0)
721 				goto out;
722 			xop->xop_data_bytes = cur_bytes;
723 		}
724 
725 		pr_debug("%s: Calling read src_dev: %p src_lba: %llu, cur_nolb: %hu\n",
726 				__func__, src_dev, (unsigned long long)src_lba, cur_nolb);
727 
728 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_bytes);
729 		if (rc < 0)
730 			goto out;
731 
732 		src_lba += cur_bytes / src_dev->dev_attrib.block_size;
733 		pr_debug("%s: Incremented READ src_lba to %llu\n", __func__,
734 				(unsigned long long)src_lba);
735 
736 		pr_debug("%s: Calling write dst_dev: %p dst_lba: %llu, cur_nolb: %u\n",
737 				__func__, dst_dev, (unsigned long long)dst_lba, cur_nolb);
738 
739 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
740 						dst_lba, cur_bytes);
741 		if (rc < 0)
742 			goto out;
743 
744 		dst_lba += cur_bytes / dst_dev->dev_attrib.block_size;
745 		pr_debug("%s: Incremented WRITE dst_lba to %llu\n", __func__,
746 				(unsigned long long)dst_lba);
747 
748 		copied_bytes += cur_bytes;
749 		nolb -= cur_bytes / src_dev->dev_attrib.block_size;
750 	}
751 
752 	xcopy_pt_undepend_remotedev(xop);
753 	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
754 	kfree(xop);
755 
756 	pr_debug("%s: Final src_lba: %llu, dst_lba: %llu\n", __func__,
757 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
758 	pr_debug("%s: Blocks copied: %u, Bytes Copied: %u\n", __func__,
759 		copied_bytes / dst_dev->dev_attrib.block_size, copied_bytes);
760 
761 	pr_debug("%s: Setting X-COPY GOOD status -> sending response\n", __func__);
762 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
763 	return;
764 
765 out:
766 	/*
767 	 * The XCOPY command was aborted after some data was transferred.
768 	 * Terminate command with CHECK CONDITION status, with the sense key
769 	 * set to COPY ABORTED.
770 	 */
771 	sense_rc = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
772 	xcopy_pt_undepend_remotedev(xop);
773 	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
774 
775 err_free:
776 	kfree(xop);
777 	pr_warn_ratelimited("%s: rc: %d, sense: %u, XCOPY operation failed\n",
778 			   __func__, rc, sense_rc);
779 	target_complete_cmd_with_sense(ec_cmd, SAM_STAT_CHECK_CONDITION, sense_rc);
780 }
781 
782 /*
783  * Returns TCM_NO_SENSE upon success or a sense code != TCM_NO_SENSE if parsing
784  * fails.
785  */
786 static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop)
787 {
788 	struct se_cmd *se_cmd = xop->xop_se_cmd;
789 	unsigned char *p = NULL, *seg_desc;
790 	unsigned int list_id, list_id_usage, sdll, inline_dl;
791 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
792 	int rc;
793 	unsigned short tdll;
794 
795 	p = transport_kmap_data_sg(se_cmd);
796 	if (!p) {
797 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
798 		return TCM_OUT_OF_RESOURCES;
799 	}
800 
801 	list_id = p[0];
802 	list_id_usage = (p[1] & 0x18) >> 3;
803 
804 	/*
805 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
806 	 */
807 	tdll = get_unaligned_be16(&p[2]);
808 	sdll = get_unaligned_be32(&p[8]);
809 	if (tdll + sdll > RCR_OP_MAX_DESC_LIST_LEN) {
810 		pr_err("XCOPY descriptor list length %u exceeds maximum %u\n",
811 		       tdll + sdll, RCR_OP_MAX_DESC_LIST_LEN);
812 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
813 		goto out;
814 	}
815 
816 	inline_dl = get_unaligned_be32(&p[12]);
817 	if (inline_dl != 0) {
818 		pr_err("XCOPY with non zero inline data length\n");
819 		goto out;
820 	}
821 
822 	if (se_cmd->data_length < (XCOPY_HDR_LEN + tdll + sdll + inline_dl)) {
823 		pr_err("XCOPY parameter truncation: data length %u too small "
824 			"for tdll: %hu sdll: %u inline_dl: %u\n",
825 			se_cmd->data_length, tdll, sdll, inline_dl);
826 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
827 		goto out;
828 	}
829 
830 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
831 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
832 		tdll, sdll, inline_dl);
833 
834 	/*
835 	 * skip over the target descriptors until segment descriptors
836 	 * have been passed - CSCD ids are needed to determine src and dest.
837 	 */
838 	seg_desc = &p[16] + tdll;
839 
840 	rc = target_xcopy_parse_segment_descriptors(xop, seg_desc, sdll, &ret);
841 	if (rc <= 0)
842 		goto out;
843 
844 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
845 				rc * XCOPY_SEGMENT_DESC_LEN);
846 
847 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll, &ret);
848 	if (rc <= 0)
849 		goto out;
850 
851 	if (xop->src_dev->dev_attrib.block_size !=
852 	    xop->dst_dev->dev_attrib.block_size) {
853 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
854 		       " block_size: %u currently unsupported\n",
855 			xop->src_dev->dev_attrib.block_size,
856 			xop->dst_dev->dev_attrib.block_size);
857 		xcopy_pt_undepend_remotedev(xop);
858 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
859 		goto out;
860 	}
861 
862 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
863 				rc * XCOPY_TARGET_DESC_LEN);
864 	transport_kunmap_data_sg(se_cmd);
865 	return TCM_NO_SENSE;
866 
867 out:
868 	if (p)
869 		transport_kunmap_data_sg(se_cmd);
870 	return ret;
871 }
872 
873 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
874 {
875 	struct se_device *dev = se_cmd->se_dev;
876 	struct xcopy_op *xop;
877 	unsigned int sa;
878 
879 	if (!dev->dev_attrib.emulate_3pc) {
880 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
881 		return TCM_UNSUPPORTED_SCSI_OPCODE;
882 	}
883 
884 	sa = se_cmd->t_task_cdb[1] & 0x1f;
885 	if (sa != 0x00) {
886 		pr_err("EXTENDED_COPY(LID4) not supported\n");
887 		return TCM_UNSUPPORTED_SCSI_OPCODE;
888 	}
889 
890 	if (se_cmd->data_length == 0) {
891 		target_complete_cmd(se_cmd, SAM_STAT_GOOD);
892 		return TCM_NO_SENSE;
893 	}
894 	if (se_cmd->data_length < XCOPY_HDR_LEN) {
895 		pr_err("XCOPY parameter truncation: length %u < hdr_len %u\n",
896 				se_cmd->data_length, XCOPY_HDR_LEN);
897 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
898 	}
899 
900 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
901 	if (!xop)
902 		goto err;
903 	xop->xop_se_cmd = se_cmd;
904 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
905 	if (WARN_ON_ONCE(!queue_work(xcopy_wq, &xop->xop_work)))
906 		goto free;
907 	return TCM_NO_SENSE;
908 
909 free:
910 	kfree(xop);
911 
912 err:
913 	return TCM_OUT_OF_RESOURCES;
914 }
915 
916 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
917 {
918 	unsigned char *p;
919 
920 	p = transport_kmap_data_sg(se_cmd);
921 	if (!p) {
922 		pr_err("transport_kmap_data_sg failed in"
923 		       " target_rcr_operating_parameters\n");
924 		return TCM_OUT_OF_RESOURCES;
925 	}
926 
927 	if (se_cmd->data_length < 54) {
928 		pr_err("Receive Copy Results Op Parameters length"
929 		       " too small: %u\n", se_cmd->data_length);
930 		transport_kunmap_data_sg(se_cmd);
931 		return TCM_INVALID_CDB_FIELD;
932 	}
933 	/*
934 	 * Set SNLID=1 (Supports no List ID)
935 	 */
936 	p[4] = 0x1;
937 	/*
938 	 * MAXIMUM TARGET DESCRIPTOR COUNT
939 	 */
940 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
941 	/*
942 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
943 	 */
944 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
945 	/*
946 	 * MAXIMUM DESCRIPTOR LIST LENGTH
947 	 */
948 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
949 	/*
950 	 * MAXIMUM SEGMENT LENGTH
951 	 */
952 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
953 	/*
954 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
955 	 */
956 	put_unaligned_be32(0x0, &p[20]);
957 	/*
958 	 * HELD DATA LIMIT
959 	 */
960 	put_unaligned_be32(0x0, &p[24]);
961 	/*
962 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
963 	 */
964 	put_unaligned_be32(0x0, &p[28]);
965 	/*
966 	 * TOTAL CONCURRENT COPIES
967 	 */
968 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
969 	/*
970 	 * MAXIMUM CONCURRENT COPIES
971 	 */
972 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
973 	/*
974 	 * DATA SEGMENT GRANULARITY (log 2)
975 	 */
976 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
977 	/*
978 	 * INLINE DATA GRANULARITY log 2)
979 	 */
980 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
981 	/*
982 	 * HELD DATA GRANULARITY
983 	 */
984 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
985 	/*
986 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
987 	 */
988 	p[43] = 0x2;
989 	/*
990 	 * List of implemented descriptor type codes (ordered)
991 	 */
992 	p[44] = 0x02; /* Copy Block to Block device */
993 	p[45] = 0xe4; /* Identification descriptor target descriptor */
994 
995 	/*
996 	 * AVAILABLE DATA (n-3)
997 	 */
998 	put_unaligned_be32(42, &p[0]);
999 
1000 	transport_kunmap_data_sg(se_cmd);
1001 	target_complete_cmd(se_cmd, SAM_STAT_GOOD);
1002 
1003 	return TCM_NO_SENSE;
1004 }
1005 
1006 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1007 {
1008 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1009 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1010 	struct se_device *dev = se_cmd->se_dev;
1011 	sense_reason_t rc = TCM_NO_SENSE;
1012 
1013 	if (!dev->dev_attrib.emulate_3pc) {
1014 		pr_debug("Third-party copy operations explicitly disabled\n");
1015 		return TCM_UNSUPPORTED_SCSI_OPCODE;
1016 	}
1017 
1018 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1019 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1020 
1021 	if (list_id != 0) {
1022 		pr_err("Receive Copy Results with non zero list identifier"
1023 		       " not supported\n");
1024 		return TCM_INVALID_CDB_FIELD;
1025 	}
1026 
1027 	switch (sa) {
1028 	case RCR_SA_OPERATING_PARAMETERS:
1029 		rc = target_rcr_operating_parameters(se_cmd);
1030 		break;
1031 	case RCR_SA_COPY_STATUS:
1032 	case RCR_SA_RECEIVE_DATA:
1033 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1034 	default:
1035 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1036 		return TCM_INVALID_CDB_FIELD;
1037 	}
1038 
1039 	return rc;
1040 }
1041