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 = rcu_dereference(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 se_cmd *se_cmd, struct xcopy_op *xop,
299 					unsigned char *p)
300 {
301 	unsigned char *desc = p;
302 	int dc = (desc[1] & 0x02);
303 	unsigned short desc_len;
304 
305 	desc_len = get_unaligned_be16(&desc[2]);
306 	if (desc_len != 0x18) {
307 		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
308 				" %hu\n", desc_len);
309 		return -EINVAL;
310 	}
311 
312 	xop->stdi = get_unaligned_be16(&desc[4]);
313 	xop->dtdi = get_unaligned_be16(&desc[6]);
314 
315 	if (xop->stdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX ||
316 	    xop->dtdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX) {
317 		pr_err("XCOPY segment desc 0x02: unsupported CSCD ID > 0x%x; stdi: %hu dtdi: %hu\n",
318 			XCOPY_CSCD_DESC_ID_LIST_OFF_MAX, xop->stdi, xop->dtdi);
319 		return -EINVAL;
320 	}
321 
322 	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
323 		desc_len, xop->stdi, xop->dtdi, dc);
324 
325 	xop->nolb = get_unaligned_be16(&desc[10]);
326 	xop->src_lba = get_unaligned_be64(&desc[12]);
327 	xop->dst_lba = get_unaligned_be64(&desc[20]);
328 	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
329 		xop->nolb, (unsigned long long)xop->src_lba,
330 		(unsigned long long)xop->dst_lba);
331 
332 	return 0;
333 }
334 
335 static int target_xcopy_parse_segment_descriptors(struct se_cmd *se_cmd,
336 				struct xcopy_op *xop, unsigned char *p,
337 				unsigned int sdll, sense_reason_t *sense_ret)
338 {
339 	unsigned char *desc = p;
340 	unsigned int start = 0;
341 	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
342 
343 	*sense_ret = TCM_INVALID_PARAMETER_LIST;
344 
345 	if (offset != 0) {
346 		pr_err("XCOPY segment descriptor list length is not"
347 			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
348 		*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
349 		return -EINVAL;
350 	}
351 	if (sdll > RCR_OP_MAX_SG_DESC_COUNT * XCOPY_SEGMENT_DESC_LEN) {
352 		pr_err("XCOPY supports %u segment descriptor(s), sdll: %u too"
353 			" large..\n", RCR_OP_MAX_SG_DESC_COUNT, sdll);
354 		/* spc4r37 6.4.3.5 SEGMENT DESCRIPTOR LIST LENGTH field */
355 		*sense_ret = TCM_TOO_MANY_SEGMENT_DESCS;
356 		return -EINVAL;
357 	}
358 
359 	while (start < sdll) {
360 		/*
361 		 * Check segment descriptor type code for block -> block
362 		 */
363 		switch (desc[0]) {
364 		case 0x02:
365 			rc = target_xcopy_parse_segdesc_02(se_cmd, xop, desc);
366 			if (rc < 0)
367 				goto out;
368 
369 			ret++;
370 			start += XCOPY_SEGMENT_DESC_LEN;
371 			desc += XCOPY_SEGMENT_DESC_LEN;
372 			break;
373 		default:
374 			pr_err("XCOPY unsupported segment descriptor"
375 				"type: 0x%02x\n", desc[0]);
376 			*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
377 			goto out;
378 		}
379 	}
380 
381 	return ret;
382 
383 out:
384 	return -EINVAL;
385 }
386 
387 /*
388  * Start xcopy_pt ops
389  */
390 
391 struct xcopy_pt_cmd {
392 	struct se_cmd se_cmd;
393 	struct completion xpt_passthrough_sem;
394 	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
395 };
396 
397 struct se_portal_group xcopy_pt_tpg;
398 static struct se_session xcopy_pt_sess;
399 static struct se_node_acl xcopy_pt_nacl;
400 
401 static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
402 {
403         return 0;
404 }
405 
406 static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
407 {
408 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
409 		pr_debug("putting dst lun_ref for %p\n", xop->dst_dev);
410 	else
411 		pr_debug("putting src lun_ref for %p\n", xop->src_dev);
412 
413 	percpu_ref_put(xop->remote_lun_ref);
414 }
415 
416 static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
417 {
418 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
419 				struct xcopy_pt_cmd, se_cmd);
420 
421 	/* xpt_cmd is on the stack, nothing to free here */
422 	pr_debug("xpt_cmd done: %p\n", xpt_cmd);
423 }
424 
425 static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
426 {
427 	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
428 				struct xcopy_pt_cmd, se_cmd);
429 
430 	complete(&xpt_cmd->xpt_passthrough_sem);
431 	return 0;
432 }
433 
434 static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
435 {
436 	return 0;
437 }
438 
439 static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
440 {
441 	return 0;
442 }
443 
444 static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
445 {
446 	return 0;
447 }
448 
449 static const struct target_core_fabric_ops xcopy_pt_tfo = {
450 	.fabric_name		= "xcopy-pt",
451 	.get_cmd_state		= xcopy_pt_get_cmd_state,
452 	.release_cmd		= xcopy_pt_release_cmd,
453 	.check_stop_free	= xcopy_pt_check_stop_free,
454 	.write_pending		= xcopy_pt_write_pending,
455 	.queue_data_in		= xcopy_pt_queue_data_in,
456 	.queue_status		= xcopy_pt_queue_status,
457 };
458 
459 /*
460  * End xcopy_pt_ops
461  */
462 
463 int target_xcopy_setup_pt(void)
464 {
465 	int ret;
466 
467 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
468 	if (!xcopy_wq) {
469 		pr_err("Unable to allocate xcopy_wq\n");
470 		return -ENOMEM;
471 	}
472 
473 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
474 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
475 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
476 
477 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
478 
479 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
480 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
481 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
482 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
483 	ret = transport_init_session(&xcopy_pt_sess);
484 	if (ret < 0)
485 		goto destroy_wq;
486 
487 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
488 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
489 
490 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
491 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
492 
493 	return 0;
494 
495 destroy_wq:
496 	destroy_workqueue(xcopy_wq);
497 	xcopy_wq = NULL;
498 	return ret;
499 }
500 
501 void target_xcopy_release_pt(void)
502 {
503 	if (xcopy_wq) {
504 		destroy_workqueue(xcopy_wq);
505 		transport_uninit_session(&xcopy_pt_sess);
506 	}
507 }
508 
509 /*
510  * target_xcopy_setup_pt_cmd - set up a pass-through command
511  * @xpt_cmd:	 Data structure to initialize.
512  * @xop:	 Describes the XCOPY operation received from an initiator.
513  * @se_dev:	 Backend device to associate with @xpt_cmd if
514  *		 @remote_port == true.
515  * @cdb:	 SCSI CDB to be copied into @xpt_cmd.
516  * @remote_port: If false, use the LUN through which the XCOPY command has
517  *		 been received. If true, use @se_dev->xcopy_lun.
518  *
519  * Set up a SCSI command (READ or WRITE) that will be used to execute an
520  * XCOPY command.
521  */
522 static int target_xcopy_setup_pt_cmd(
523 	struct xcopy_pt_cmd *xpt_cmd,
524 	struct xcopy_op *xop,
525 	struct se_device *se_dev,
526 	unsigned char *cdb,
527 	bool remote_port)
528 {
529 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
530 
531 	/*
532 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
533 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
534 	 */
535 	if (remote_port) {
536 		cmd->se_lun = &se_dev->xcopy_lun;
537 		cmd->se_dev = se_dev;
538 	} else {
539 		cmd->se_lun = xop->xop_se_cmd->se_lun;
540 		cmd->se_dev = xop->xop_se_cmd->se_dev;
541 	}
542 	cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
543 
544 	if (target_cmd_init_cdb(cmd, cdb, GFP_KERNEL))
545 		return -EINVAL;
546 
547 	cmd->tag = 0;
548 	if (target_cmd_parse_cdb(cmd))
549 		return -EINVAL;
550 
551 	if (transport_generic_map_mem_to_cmd(cmd, xop->xop_data_sg,
552 					xop->xop_data_nents, NULL, 0))
553 		return -EINVAL;
554 
555 	pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
556 		 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
557 
558 	return 0;
559 }
560 
561 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
562 {
563 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
564 	sense_reason_t sense_rc;
565 
566 	sense_rc = transport_generic_new_cmd(se_cmd);
567 	if (sense_rc)
568 		return -EINVAL;
569 
570 	if (se_cmd->data_direction == DMA_TO_DEVICE)
571 		target_execute_cmd(se_cmd);
572 
573 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
574 
575 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
576 			se_cmd->scsi_status);
577 
578 	return (se_cmd->scsi_status) ? -EINVAL : 0;
579 }
580 
581 static int target_xcopy_read_source(
582 	struct se_cmd *ec_cmd,
583 	struct xcopy_op *xop,
584 	struct se_device *src_dev,
585 	sector_t src_lba,
586 	u32 src_sectors)
587 {
588 	struct xcopy_pt_cmd xpt_cmd;
589 	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
590 	u32 length = (src_sectors * src_dev->dev_attrib.block_size);
591 	int rc;
592 	unsigned char cdb[16];
593 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
594 
595 	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
596 	init_completion(&xpt_cmd.xpt_passthrough_sem);
597 
598 	memset(&cdb[0], 0, 16);
599 	cdb[0] = READ_16;
600 	put_unaligned_be64(src_lba, &cdb[2]);
601 	put_unaligned_be32(src_sectors, &cdb[10]);
602 	pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
603 		(unsigned long long)src_lba, src_sectors, length);
604 
605 	__target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
606 			  DMA_FROM_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0);
607 
608 	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, src_dev, &cdb[0],
609 				remote_port);
610 	if (rc < 0) {
611 		ec_cmd->scsi_status = se_cmd->scsi_status;
612 		goto out;
613 	}
614 
615 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
616 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
617 
618 	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
619 	if (rc < 0)
620 		ec_cmd->scsi_status = se_cmd->scsi_status;
621 out:
622 	transport_generic_free_cmd(se_cmd, 0);
623 	return rc;
624 }
625 
626 static int target_xcopy_write_destination(
627 	struct se_cmd *ec_cmd,
628 	struct xcopy_op *xop,
629 	struct se_device *dst_dev,
630 	sector_t dst_lba,
631 	u32 dst_sectors)
632 {
633 	struct xcopy_pt_cmd xpt_cmd;
634 	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
635 	u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
636 	int rc;
637 	unsigned char cdb[16];
638 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
639 
640 	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
641 	init_completion(&xpt_cmd.xpt_passthrough_sem);
642 
643 	memset(&cdb[0], 0, 16);
644 	cdb[0] = WRITE_16;
645 	put_unaligned_be64(dst_lba, &cdb[2]);
646 	put_unaligned_be32(dst_sectors, &cdb[10]);
647 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
648 		(unsigned long long)dst_lba, dst_sectors, length);
649 
650 	__target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
651 			  DMA_TO_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0);
652 
653 	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, dst_dev, &cdb[0],
654 				remote_port);
655 	if (rc < 0) {
656 		ec_cmd->scsi_status = se_cmd->scsi_status;
657 		goto out;
658 	}
659 
660 	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
661 	if (rc < 0)
662 		ec_cmd->scsi_status = se_cmd->scsi_status;
663 out:
664 	transport_generic_free_cmd(se_cmd, 0);
665 	return rc;
666 }
667 
668 static void target_xcopy_do_work(struct work_struct *work)
669 {
670 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
671 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
672 	struct se_device *src_dev, *dst_dev;
673 	sector_t src_lba, dst_lba, end_lba;
674 	unsigned int max_sectors;
675 	int rc = 0;
676 	unsigned short nolb, max_nolb, copied_nolb = 0;
677 
678 	if (target_parse_xcopy_cmd(xop) != TCM_NO_SENSE)
679 		goto err_free;
680 
681 	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev))
682 		goto err_free;
683 
684 	src_dev = xop->src_dev;
685 	dst_dev = xop->dst_dev;
686 	src_lba = xop->src_lba;
687 	dst_lba = xop->dst_lba;
688 	nolb = xop->nolb;
689 	end_lba = src_lba + nolb;
690 	/*
691 	 * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
692 	 * smallest max_sectors between src_dev + dev_dev, or
693 	 */
694 	max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
695 			  dst_dev->dev_attrib.hw_max_sectors);
696 	max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
697 
698 	max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
699 
700 	pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
701 			nolb, max_nolb, (unsigned long long)end_lba);
702 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
703 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
704 
705 	while (src_lba < end_lba) {
706 		unsigned short cur_nolb = min(nolb, max_nolb);
707 		u32 cur_bytes = cur_nolb * src_dev->dev_attrib.block_size;
708 
709 		if (cur_bytes != xop->xop_data_bytes) {
710 			/*
711 			 * (Re)allocate a buffer large enough to hold the XCOPY
712 			 * I/O size, which can be reused each read / write loop.
713 			 */
714 			target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
715 			rc = target_alloc_sgl(&xop->xop_data_sg,
716 					      &xop->xop_data_nents,
717 					      cur_bytes,
718 					      false, false);
719 			if (rc < 0)
720 				goto out;
721 			xop->xop_data_bytes = cur_bytes;
722 		}
723 
724 		pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
725 			" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
726 
727 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
728 		if (rc < 0)
729 			goto out;
730 
731 		src_lba += cur_nolb;
732 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
733 				(unsigned long long)src_lba);
734 
735 		pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
736 			" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
737 
738 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
739 						dst_lba, cur_nolb);
740 		if (rc < 0)
741 			goto out;
742 
743 		dst_lba += cur_nolb;
744 		pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
745 				(unsigned long long)dst_lba);
746 
747 		copied_nolb += cur_nolb;
748 		nolb -= cur_nolb;
749 	}
750 
751 	xcopy_pt_undepend_remotedev(xop);
752 	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
753 	kfree(xop);
754 
755 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
756 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
757 	pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
758 		copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
759 
760 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
761 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
762 	return;
763 
764 out:
765 	xcopy_pt_undepend_remotedev(xop);
766 	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
767 
768 err_free:
769 	kfree(xop);
770 	/*
771 	 * Don't override an error scsi status if it has already been set
772 	 */
773 	if (ec_cmd->scsi_status == SAM_STAT_GOOD) {
774 		pr_warn_ratelimited("target_xcopy_do_work: rc: %d, Setting X-COPY"
775 			" CHECK_CONDITION -> sending response\n", rc);
776 		ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
777 	}
778 	target_complete_cmd(ec_cmd, ec_cmd->scsi_status);
779 }
780 
781 /*
782  * Returns TCM_NO_SENSE upon success or a sense code != TCM_NO_SENSE if parsing
783  * fails.
784  */
785 static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop)
786 {
787 	struct se_cmd *se_cmd = xop->xop_se_cmd;
788 	unsigned char *p = NULL, *seg_desc;
789 	unsigned int list_id, list_id_usage, sdll, inline_dl;
790 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
791 	int rc;
792 	unsigned short tdll;
793 
794 	p = transport_kmap_data_sg(se_cmd);
795 	if (!p) {
796 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
797 		return TCM_OUT_OF_RESOURCES;
798 	}
799 
800 	list_id = p[0];
801 	list_id_usage = (p[1] & 0x18) >> 3;
802 
803 	/*
804 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
805 	 */
806 	tdll = get_unaligned_be16(&p[2]);
807 	sdll = get_unaligned_be32(&p[8]);
808 	if (tdll + sdll > RCR_OP_MAX_DESC_LIST_LEN) {
809 		pr_err("XCOPY descriptor list length %u exceeds maximum %u\n",
810 		       tdll + sdll, RCR_OP_MAX_DESC_LIST_LEN);
811 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
812 		goto out;
813 	}
814 
815 	inline_dl = get_unaligned_be32(&p[12]);
816 	if (inline_dl != 0) {
817 		pr_err("XCOPY with non zero inline data length\n");
818 		goto out;
819 	}
820 
821 	if (se_cmd->data_length < (XCOPY_HDR_LEN + tdll + sdll + inline_dl)) {
822 		pr_err("XCOPY parameter truncation: data length %u too small "
823 			"for tdll: %hu sdll: %u inline_dl: %u\n",
824 			se_cmd->data_length, tdll, sdll, inline_dl);
825 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
826 		goto out;
827 	}
828 
829 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
830 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
831 		tdll, sdll, inline_dl);
832 
833 	/*
834 	 * skip over the target descriptors until segment descriptors
835 	 * have been passed - CSCD ids are needed to determine src and dest.
836 	 */
837 	seg_desc = &p[16] + tdll;
838 
839 	rc = target_xcopy_parse_segment_descriptors(se_cmd, xop, seg_desc,
840 						    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 	sense_reason_t rc = TCM_NO_SENSE;
1011 
1012 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1013 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1014 
1015 	if (list_id != 0) {
1016 		pr_err("Receive Copy Results with non zero list identifier"
1017 		       " not supported\n");
1018 		return TCM_INVALID_CDB_FIELD;
1019 	}
1020 
1021 	switch (sa) {
1022 	case RCR_SA_OPERATING_PARAMETERS:
1023 		rc = target_rcr_operating_parameters(se_cmd);
1024 		break;
1025 	case RCR_SA_COPY_STATUS:
1026 	case RCR_SA_RECEIVE_DATA:
1027 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1028 	default:
1029 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1030 		return TCM_INVALID_CDB_FIELD;
1031 	}
1032 
1033 	return rc;
1034 }
1035