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 	int ret;
465 
466 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
467 	if (!xcopy_wq) {
468 		pr_err("Unable to allocate xcopy_wq\n");
469 		return -ENOMEM;
470 	}
471 
472 	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
473 	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
474 	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
475 
476 	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
477 
478 	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
479 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
480 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
481 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
482 	ret = transport_init_session(&xcopy_pt_sess);
483 	if (ret < 0)
484 		goto destroy_wq;
485 
486 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
487 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
488 
489 	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
490 	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
491 
492 	return 0;
493 
494 destroy_wq:
495 	destroy_workqueue(xcopy_wq);
496 	xcopy_wq = NULL;
497 	return ret;
498 }
499 
500 void target_xcopy_release_pt(void)
501 {
502 	if (xcopy_wq) {
503 		destroy_workqueue(xcopy_wq);
504 		transport_uninit_session(&xcopy_pt_sess);
505 	}
506 }
507 
508 /*
509  * target_xcopy_setup_pt_cmd - set up a pass-through command
510  * @xpt_cmd:	 Data structure to initialize.
511  * @xop:	 Describes the XCOPY operation received from an initiator.
512  * @se_dev:	 Backend device to associate with @xpt_cmd if
513  *		 @remote_port == true.
514  * @cdb:	 SCSI CDB to be copied into @xpt_cmd.
515  * @remote_port: If false, use the LUN through which the XCOPY command has
516  *		 been received. If true, use @se_dev->xcopy_lun.
517  *
518  * Set up a SCSI command (READ or WRITE) that will be used to execute an
519  * XCOPY command.
520  */
521 static int target_xcopy_setup_pt_cmd(
522 	struct xcopy_pt_cmd *xpt_cmd,
523 	struct xcopy_op *xop,
524 	struct se_device *se_dev,
525 	unsigned char *cdb,
526 	bool remote_port)
527 {
528 	struct se_cmd *cmd = &xpt_cmd->se_cmd;
529 
530 	/*
531 	 * Setup LUN+port to honor reservations based upon xop->op_origin for
532 	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
533 	 */
534 	if (remote_port) {
535 		cmd->se_lun = &se_dev->xcopy_lun;
536 		cmd->se_dev = se_dev;
537 	} else {
538 		cmd->se_lun = xop->xop_se_cmd->se_lun;
539 		cmd->se_dev = xop->xop_se_cmd->se_dev;
540 	}
541 	cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
542 
543 	if (target_cmd_init_cdb(cmd, cdb, GFP_KERNEL))
544 		return -EINVAL;
545 
546 	cmd->tag = 0;
547 	if (target_cmd_parse_cdb(cmd))
548 		return -EINVAL;
549 
550 	if (transport_generic_map_mem_to_cmd(cmd, xop->xop_data_sg,
551 					xop->xop_data_nents, NULL, 0))
552 		return -EINVAL;
553 
554 	pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
555 		 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
556 
557 	return 0;
558 }
559 
560 static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
561 {
562 	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
563 	sense_reason_t sense_rc;
564 
565 	sense_rc = transport_generic_new_cmd(se_cmd);
566 	if (sense_rc)
567 		return -EINVAL;
568 
569 	if (se_cmd->data_direction == DMA_TO_DEVICE)
570 		target_execute_cmd(se_cmd);
571 
572 	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
573 
574 	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
575 			se_cmd->scsi_status);
576 
577 	return (se_cmd->scsi_status) ? -EINVAL : 0;
578 }
579 
580 static int target_xcopy_read_source(
581 	struct se_cmd *ec_cmd,
582 	struct xcopy_op *xop,
583 	struct se_device *src_dev,
584 	sector_t src_lba,
585 	u32 src_bytes)
586 {
587 	struct xcopy_pt_cmd xpt_cmd;
588 	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
589 	u32 transfer_length_block = src_bytes / src_dev->dev_attrib.block_size;
590 	int rc;
591 	unsigned char cdb[16];
592 	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
593 
594 	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
595 	init_completion(&xpt_cmd.xpt_passthrough_sem);
596 
597 	memset(&cdb[0], 0, 16);
598 	cdb[0] = READ_16;
599 	put_unaligned_be64(src_lba, &cdb[2]);
600 	put_unaligned_be32(transfer_length_block, &cdb[10]);
601 	pr_debug("XCOPY: Built READ_16: LBA: %llu Blocks: %u Length: %u\n",
602 		(unsigned long long)src_lba, transfer_length_block, src_bytes);
603 
604 	__target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, src_bytes,
605 			  DMA_FROM_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0);
606 
607 	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, src_dev, &cdb[0],
608 				remote_port);
609 	if (rc < 0) {
610 		ec_cmd->scsi_status = se_cmd->scsi_status;
611 		goto out;
612 	}
613 
614 	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
615 		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
616 
617 	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
618 	if (rc < 0)
619 		ec_cmd->scsi_status = se_cmd->scsi_status;
620 out:
621 	transport_generic_free_cmd(se_cmd, 0);
622 	return rc;
623 }
624 
625 static int target_xcopy_write_destination(
626 	struct se_cmd *ec_cmd,
627 	struct xcopy_op *xop,
628 	struct se_device *dst_dev,
629 	sector_t dst_lba,
630 	u32 dst_bytes)
631 {
632 	struct xcopy_pt_cmd xpt_cmd;
633 	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
634 	u32 transfer_length_block = dst_bytes / dst_dev->dev_attrib.block_size;
635 	int rc;
636 	unsigned char cdb[16];
637 	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
638 
639 	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
640 	init_completion(&xpt_cmd.xpt_passthrough_sem);
641 
642 	memset(&cdb[0], 0, 16);
643 	cdb[0] = WRITE_16;
644 	put_unaligned_be64(dst_lba, &cdb[2]);
645 	put_unaligned_be32(transfer_length_block, &cdb[10]);
646 	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Blocks: %u Length: %u\n",
647 		(unsigned long long)dst_lba, transfer_length_block, dst_bytes);
648 
649 	__target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, dst_bytes,
650 			  DMA_TO_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0);
651 
652 	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, dst_dev, &cdb[0],
653 				remote_port);
654 	if (rc < 0) {
655 		ec_cmd->scsi_status = se_cmd->scsi_status;
656 		goto out;
657 	}
658 
659 	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
660 	if (rc < 0)
661 		ec_cmd->scsi_status = se_cmd->scsi_status;
662 out:
663 	transport_generic_free_cmd(se_cmd, 0);
664 	return rc;
665 }
666 
667 static void target_xcopy_do_work(struct work_struct *work)
668 {
669 	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
670 	struct se_cmd *ec_cmd = xop->xop_se_cmd;
671 	struct se_device *src_dev, *dst_dev;
672 	sector_t src_lba, dst_lba, end_lba;
673 	unsigned long long max_bytes, max_bytes_src, max_bytes_dst, max_blocks;
674 	int rc = 0;
675 	unsigned short nolb;
676 	unsigned int copied_bytes = 0;
677 	sense_reason_t sense_rc;
678 
679 	sense_rc = target_parse_xcopy_cmd(xop);
680 	if (sense_rc != TCM_NO_SENSE)
681 		goto err_free;
682 
683 	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev)) {
684 		sense_rc = TCM_INVALID_PARAMETER_LIST;
685 		goto err_free;
686 	}
687 
688 	src_dev = xop->src_dev;
689 	dst_dev = xop->dst_dev;
690 	src_lba = xop->src_lba;
691 	dst_lba = xop->dst_lba;
692 	nolb = xop->nolb;
693 	end_lba = src_lba + nolb;
694 	/*
695 	 * Break up XCOPY I/O into hw_max_sectors * hw_block_size sized
696 	 * I/O based on the smallest max_bytes between src_dev + dst_dev
697 	 */
698 	max_bytes_src = (unsigned long long) src_dev->dev_attrib.hw_max_sectors *
699 			src_dev->dev_attrib.hw_block_size;
700 	max_bytes_dst = (unsigned long long) dst_dev->dev_attrib.hw_max_sectors *
701 			dst_dev->dev_attrib.hw_block_size;
702 
703 	max_bytes = min_t(u64, max_bytes_src, max_bytes_dst);
704 	max_bytes = min_t(u64, max_bytes, XCOPY_MAX_BYTES);
705 
706 	/*
707 	 * Using shift instead of the division because otherwise GCC
708 	 * generates __udivdi3 that is missing on i386
709 	 */
710 	max_blocks = max_bytes >> ilog2(src_dev->dev_attrib.block_size);
711 
712 	pr_debug("%s: nolb: %u, max_blocks: %llu end_lba: %llu\n", __func__,
713 			nolb, max_blocks, (unsigned long long)end_lba);
714 	pr_debug("%s: Starting src_lba: %llu, dst_lba: %llu\n", __func__,
715 			(unsigned long long)src_lba, (unsigned long long)dst_lba);
716 
717 	while (nolb) {
718 		u32 cur_bytes = min_t(u64, max_bytes, nolb * src_dev->dev_attrib.block_size);
719 		unsigned short cur_nolb = cur_bytes / src_dev->dev_attrib.block_size;
720 
721 		if (cur_bytes != xop->xop_data_bytes) {
722 			/*
723 			 * (Re)allocate a buffer large enough to hold the XCOPY
724 			 * I/O size, which can be reused each read / write loop.
725 			 */
726 			target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
727 			rc = target_alloc_sgl(&xop->xop_data_sg,
728 					      &xop->xop_data_nents,
729 					      cur_bytes,
730 					      false, false);
731 			if (rc < 0)
732 				goto out;
733 			xop->xop_data_bytes = cur_bytes;
734 		}
735 
736 		pr_debug("%s: Calling read src_dev: %p src_lba: %llu, cur_nolb: %hu\n",
737 				__func__, src_dev, (unsigned long long)src_lba, cur_nolb);
738 
739 		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_bytes);
740 		if (rc < 0)
741 			goto out;
742 
743 		src_lba += cur_bytes / src_dev->dev_attrib.block_size;
744 		pr_debug("%s: Incremented READ src_lba to %llu\n", __func__,
745 				(unsigned long long)src_lba);
746 
747 		pr_debug("%s: Calling write dst_dev: %p dst_lba: %llu, cur_nolb: %u\n",
748 				__func__, dst_dev, (unsigned long long)dst_lba, cur_nolb);
749 
750 		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
751 						dst_lba, cur_bytes);
752 		if (rc < 0)
753 			goto out;
754 
755 		dst_lba += cur_bytes / dst_dev->dev_attrib.block_size;
756 		pr_debug("%s: Incremented WRITE dst_lba to %llu\n", __func__,
757 				(unsigned long long)dst_lba);
758 
759 		copied_bytes += cur_bytes;
760 		nolb -= cur_bytes / src_dev->dev_attrib.block_size;
761 	}
762 
763 	xcopy_pt_undepend_remotedev(xop);
764 	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
765 	kfree(xop);
766 
767 	pr_debug("%s: Final src_lba: %llu, dst_lba: %llu\n", __func__,
768 		(unsigned long long)src_lba, (unsigned long long)dst_lba);
769 	pr_debug("%s: Blocks copied: %u, Bytes Copied: %u\n", __func__,
770 		copied_bytes / dst_dev->dev_attrib.block_size, copied_bytes);
771 
772 	pr_debug("%s: Setting X-COPY GOOD status -> sending response\n", __func__);
773 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
774 	return;
775 
776 out:
777 	/*
778 	 * The XCOPY command was aborted after some data was transferred.
779 	 * Terminate command with CHECK CONDITION status, with the sense key
780 	 * set to COPY ABORTED.
781 	 */
782 	sense_rc = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
783 	xcopy_pt_undepend_remotedev(xop);
784 	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
785 
786 err_free:
787 	kfree(xop);
788 	pr_warn_ratelimited("%s: rc: %d, sense: %u, XCOPY operation failed\n",
789 			   __func__, rc, sense_rc);
790 	target_complete_cmd_with_sense(ec_cmd, SAM_STAT_CHECK_CONDITION, sense_rc);
791 }
792 
793 /*
794  * Returns TCM_NO_SENSE upon success or a sense code != TCM_NO_SENSE if parsing
795  * fails.
796  */
797 static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop)
798 {
799 	struct se_cmd *se_cmd = xop->xop_se_cmd;
800 	unsigned char *p = NULL, *seg_desc;
801 	unsigned int list_id, list_id_usage, sdll, inline_dl;
802 	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
803 	int rc;
804 	unsigned short tdll;
805 
806 	p = transport_kmap_data_sg(se_cmd);
807 	if (!p) {
808 		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
809 		return TCM_OUT_OF_RESOURCES;
810 	}
811 
812 	list_id = p[0];
813 	list_id_usage = (p[1] & 0x18) >> 3;
814 
815 	/*
816 	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
817 	 */
818 	tdll = get_unaligned_be16(&p[2]);
819 	sdll = get_unaligned_be32(&p[8]);
820 	if (tdll + sdll > RCR_OP_MAX_DESC_LIST_LEN) {
821 		pr_err("XCOPY descriptor list length %u exceeds maximum %u\n",
822 		       tdll + sdll, RCR_OP_MAX_DESC_LIST_LEN);
823 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
824 		goto out;
825 	}
826 
827 	inline_dl = get_unaligned_be32(&p[12]);
828 	if (inline_dl != 0) {
829 		pr_err("XCOPY with non zero inline data length\n");
830 		goto out;
831 	}
832 
833 	if (se_cmd->data_length < (XCOPY_HDR_LEN + tdll + sdll + inline_dl)) {
834 		pr_err("XCOPY parameter truncation: data length %u too small "
835 			"for tdll: %hu sdll: %u inline_dl: %u\n",
836 			se_cmd->data_length, tdll, sdll, inline_dl);
837 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
838 		goto out;
839 	}
840 
841 	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
842 		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
843 		tdll, sdll, inline_dl);
844 
845 	/*
846 	 * skip over the target descriptors until segment descriptors
847 	 * have been passed - CSCD ids are needed to determine src and dest.
848 	 */
849 	seg_desc = &p[16] + tdll;
850 
851 	rc = target_xcopy_parse_segment_descriptors(xop, seg_desc, sdll, &ret);
852 	if (rc <= 0)
853 		goto out;
854 
855 	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
856 				rc * XCOPY_SEGMENT_DESC_LEN);
857 
858 	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll, &ret);
859 	if (rc <= 0)
860 		goto out;
861 
862 	if (xop->src_dev->dev_attrib.block_size !=
863 	    xop->dst_dev->dev_attrib.block_size) {
864 		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
865 		       " block_size: %u currently unsupported\n",
866 			xop->src_dev->dev_attrib.block_size,
867 			xop->dst_dev->dev_attrib.block_size);
868 		xcopy_pt_undepend_remotedev(xop);
869 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
870 		goto out;
871 	}
872 
873 	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
874 				rc * XCOPY_TARGET_DESC_LEN);
875 	transport_kunmap_data_sg(se_cmd);
876 	return TCM_NO_SENSE;
877 
878 out:
879 	if (p)
880 		transport_kunmap_data_sg(se_cmd);
881 	return ret;
882 }
883 
884 sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
885 {
886 	struct se_device *dev = se_cmd->se_dev;
887 	struct xcopy_op *xop;
888 	unsigned int sa;
889 
890 	if (!dev->dev_attrib.emulate_3pc) {
891 		pr_err("EXTENDED_COPY operation explicitly disabled\n");
892 		return TCM_UNSUPPORTED_SCSI_OPCODE;
893 	}
894 
895 	sa = se_cmd->t_task_cdb[1] & 0x1f;
896 	if (sa != 0x00) {
897 		pr_err("EXTENDED_COPY(LID4) not supported\n");
898 		return TCM_UNSUPPORTED_SCSI_OPCODE;
899 	}
900 
901 	if (se_cmd->data_length == 0) {
902 		target_complete_cmd(se_cmd, SAM_STAT_GOOD);
903 		return TCM_NO_SENSE;
904 	}
905 	if (se_cmd->data_length < XCOPY_HDR_LEN) {
906 		pr_err("XCOPY parameter truncation: length %u < hdr_len %u\n",
907 				se_cmd->data_length, XCOPY_HDR_LEN);
908 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
909 	}
910 
911 	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
912 	if (!xop)
913 		goto err;
914 	xop->xop_se_cmd = se_cmd;
915 	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
916 	if (WARN_ON_ONCE(!queue_work(xcopy_wq, &xop->xop_work)))
917 		goto free;
918 	return TCM_NO_SENSE;
919 
920 free:
921 	kfree(xop);
922 
923 err:
924 	return TCM_OUT_OF_RESOURCES;
925 }
926 
927 static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
928 {
929 	unsigned char *p;
930 
931 	p = transport_kmap_data_sg(se_cmd);
932 	if (!p) {
933 		pr_err("transport_kmap_data_sg failed in"
934 		       " target_rcr_operating_parameters\n");
935 		return TCM_OUT_OF_RESOURCES;
936 	}
937 
938 	if (se_cmd->data_length < 54) {
939 		pr_err("Receive Copy Results Op Parameters length"
940 		       " too small: %u\n", se_cmd->data_length);
941 		transport_kunmap_data_sg(se_cmd);
942 		return TCM_INVALID_CDB_FIELD;
943 	}
944 	/*
945 	 * Set SNLID=1 (Supports no List ID)
946 	 */
947 	p[4] = 0x1;
948 	/*
949 	 * MAXIMUM TARGET DESCRIPTOR COUNT
950 	 */
951 	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
952 	/*
953 	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
954 	 */
955 	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
956 	/*
957 	 * MAXIMUM DESCRIPTOR LIST LENGTH
958 	 */
959 	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
960 	/*
961 	 * MAXIMUM SEGMENT LENGTH
962 	 */
963 	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
964 	/*
965 	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
966 	 */
967 	put_unaligned_be32(0x0, &p[20]);
968 	/*
969 	 * HELD DATA LIMIT
970 	 */
971 	put_unaligned_be32(0x0, &p[24]);
972 	/*
973 	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
974 	 */
975 	put_unaligned_be32(0x0, &p[28]);
976 	/*
977 	 * TOTAL CONCURRENT COPIES
978 	 */
979 	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
980 	/*
981 	 * MAXIMUM CONCURRENT COPIES
982 	 */
983 	p[36] = RCR_OP_MAX_CONCURR_COPIES;
984 	/*
985 	 * DATA SEGMENT GRANULARITY (log 2)
986 	 */
987 	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
988 	/*
989 	 * INLINE DATA GRANULARITY log 2)
990 	 */
991 	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
992 	/*
993 	 * HELD DATA GRANULARITY
994 	 */
995 	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
996 	/*
997 	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
998 	 */
999 	p[43] = 0x2;
1000 	/*
1001 	 * List of implemented descriptor type codes (ordered)
1002 	 */
1003 	p[44] = 0x02; /* Copy Block to Block device */
1004 	p[45] = 0xe4; /* Identification descriptor target descriptor */
1005 
1006 	/*
1007 	 * AVAILABLE DATA (n-3)
1008 	 */
1009 	put_unaligned_be32(42, &p[0]);
1010 
1011 	transport_kunmap_data_sg(se_cmd);
1012 	target_complete_cmd(se_cmd, SAM_STAT_GOOD);
1013 
1014 	return TCM_NO_SENSE;
1015 }
1016 
1017 sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1018 {
1019 	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1020 	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1021 	struct se_device *dev = se_cmd->se_dev;
1022 	sense_reason_t rc = TCM_NO_SENSE;
1023 
1024 	if (!dev->dev_attrib.emulate_3pc) {
1025 		pr_debug("Third-party copy operations explicitly disabled\n");
1026 		return TCM_UNSUPPORTED_SCSI_OPCODE;
1027 	}
1028 
1029 	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1030 		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1031 
1032 	if (list_id != 0) {
1033 		pr_err("Receive Copy Results with non zero list identifier"
1034 		       " not supported\n");
1035 		return TCM_INVALID_CDB_FIELD;
1036 	}
1037 
1038 	switch (sa) {
1039 	case RCR_SA_OPERATING_PARAMETERS:
1040 		rc = target_rcr_operating_parameters(se_cmd);
1041 		break;
1042 	case RCR_SA_COPY_STATUS:
1043 	case RCR_SA_RECEIVE_DATA:
1044 	case RCR_SA_FAILED_SEGMENT_DETAILS:
1045 	default:
1046 		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1047 		return TCM_INVALID_CDB_FIELD;
1048 	}
1049 
1050 	return rc;
1051 }
1052