1 /*******************************************************************************
2  * Filename:  target_core_pr.c
3  *
4  * This file contains SPC-3 compliant persistent reservations and
5  * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
6  *
7  * (c) Copyright 2009-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24  *
25  ******************************************************************************/
26 
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/list.h>
30 #include <linux/file.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_cmnd.h>
33 #include <asm/unaligned.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_backend.h>
37 #include <target/target_core_fabric.h>
38 #include <target/target_core_configfs.h>
39 
40 #include "target_core_internal.h"
41 #include "target_core_pr.h"
42 #include "target_core_ua.h"
43 
44 /*
45  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
46  */
47 struct pr_transport_id_holder {
48 	int dest_local_nexus;
49 	struct t10_pr_registration *dest_pr_reg;
50 	struct se_portal_group *dest_tpg;
51 	struct se_node_acl *dest_node_acl;
52 	struct se_dev_entry *dest_se_deve;
53 	struct list_head dest_list;
54 };
55 
56 void core_pr_dump_initiator_port(
57 	struct t10_pr_registration *pr_reg,
58 	char *buf,
59 	u32 size)
60 {
61 	if (!pr_reg->isid_present_at_reg)
62 		buf[0] = '\0';
63 
64 	snprintf(buf, size, ",i,0x%s", pr_reg->pr_reg_isid);
65 }
66 
67 enum register_type {
68 	REGISTER,
69 	REGISTER_AND_IGNORE_EXISTING_KEY,
70 	REGISTER_AND_MOVE,
71 };
72 
73 enum preempt_type {
74 	PREEMPT,
75 	PREEMPT_AND_ABORT,
76 };
77 
78 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
79 					      struct t10_pr_registration *, int, int);
80 
81 static int is_reservation_holder(
82 	struct t10_pr_registration *pr_res_holder,
83 	struct t10_pr_registration *pr_reg)
84 {
85 	int pr_res_type;
86 
87 	if (pr_res_holder) {
88 		pr_res_type = pr_res_holder->pr_res_type;
89 
90 		return pr_res_holder == pr_reg ||
91 		       pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
92 		       pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG;
93 	}
94 	return 0;
95 }
96 
97 static sense_reason_t
98 target_scsi2_reservation_check(struct se_cmd *cmd)
99 {
100 	struct se_device *dev = cmd->se_dev;
101 	struct se_session *sess = cmd->se_sess;
102 
103 	switch (cmd->t_task_cdb[0]) {
104 	case INQUIRY:
105 	case RELEASE:
106 	case RELEASE_10:
107 		return 0;
108 	default:
109 		break;
110 	}
111 
112 	if (!dev->dev_reserved_node_acl || !sess)
113 		return 0;
114 
115 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
116 		return TCM_RESERVATION_CONFLICT;
117 
118 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
119 		if (dev->dev_res_bin_isid != sess->sess_bin_isid)
120 			return TCM_RESERVATION_CONFLICT;
121 	}
122 
123 	return 0;
124 }
125 
126 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
127 					struct se_node_acl *, struct se_session *);
128 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
129 
130 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
131 {
132 	struct se_session *se_sess = cmd->se_sess;
133 	struct se_device *dev = cmd->se_dev;
134 	struct t10_pr_registration *pr_reg;
135 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
136 	int conflict = 0;
137 
138 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
139 			se_sess);
140 	if (pr_reg) {
141 		/*
142 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
143 		 * behavior
144 		 *
145 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
146 		 * status, but no reservation shall be established and the
147 		 * persistent reservation shall not be changed, if the command
148 		 * is received from a) and b) below.
149 		 *
150 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
151 		 * status, but the persistent reservation shall not be released,
152 		 * if the command is received from a) and b)
153 		 *
154 		 * a) An I_T nexus that is a persistent reservation holder; or
155 		 * b) An I_T nexus that is registered if a registrants only or
156 		 *    all registrants type persistent reservation is present.
157 		 *
158 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
159 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
160 		 * as defined in SPC-2.
161 		 */
162 		if (pr_reg->pr_res_holder) {
163 			core_scsi3_put_pr_reg(pr_reg);
164 			return 1;
165 		}
166 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
167 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
168 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
169 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
170 			core_scsi3_put_pr_reg(pr_reg);
171 			return 1;
172 		}
173 		core_scsi3_put_pr_reg(pr_reg);
174 		conflict = 1;
175 	} else {
176 		/*
177 		 * Following spc2r20 5.5.1 Reservations overview:
178 		 *
179 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
180 		 * command with the REGISTER or the REGISTER AND IGNORE
181 		 * EXISTING KEY service action and is still registered by any
182 		 * initiator, all RESERVE commands and all RELEASE commands
183 		 * regardless of initiator shall conflict and shall terminate
184 		 * with a RESERVATION CONFLICT status.
185 		 */
186 		spin_lock(&pr_tmpl->registration_lock);
187 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
188 		spin_unlock(&pr_tmpl->registration_lock);
189 	}
190 
191 	if (conflict) {
192 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
193 			" while active SPC-3 registrations exist,"
194 			" returning RESERVATION_CONFLICT\n");
195 		return -EBUSY;
196 	}
197 
198 	return 0;
199 }
200 
201 sense_reason_t
202 target_scsi2_reservation_release(struct se_cmd *cmd)
203 {
204 	struct se_device *dev = cmd->se_dev;
205 	struct se_session *sess = cmd->se_sess;
206 	struct se_portal_group *tpg;
207 	int rc;
208 
209 	if (!sess || !sess->se_tpg)
210 		goto out;
211 	rc = target_check_scsi2_reservation_conflict(cmd);
212 	if (rc == 1)
213 		goto out;
214 	if (rc < 0)
215 		return TCM_RESERVATION_CONFLICT;
216 
217 	spin_lock(&dev->dev_reservation_lock);
218 	if (!dev->dev_reserved_node_acl || !sess)
219 		goto out_unlock;
220 
221 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
222 		goto out_unlock;
223 
224 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
225 		goto out_unlock;
226 
227 	dev->dev_reserved_node_acl = NULL;
228 	dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
229 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
230 		dev->dev_res_bin_isid = 0;
231 		dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS_WITH_ISID;
232 	}
233 	tpg = sess->se_tpg;
234 	pr_debug("SCSI-2 Released reservation for %s LUN: %u ->"
235 		" MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
236 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
237 		sess->se_node_acl->initiatorname);
238 
239 out_unlock:
240 	spin_unlock(&dev->dev_reservation_lock);
241 out:
242 	target_complete_cmd(cmd, GOOD);
243 	return 0;
244 }
245 
246 sense_reason_t
247 target_scsi2_reservation_reserve(struct se_cmd *cmd)
248 {
249 	struct se_device *dev = cmd->se_dev;
250 	struct se_session *sess = cmd->se_sess;
251 	struct se_portal_group *tpg;
252 	sense_reason_t ret = 0;
253 	int rc;
254 
255 	if ((cmd->t_task_cdb[1] & 0x01) &&
256 	    (cmd->t_task_cdb[1] & 0x02)) {
257 		pr_err("LongIO and Obselete Bits set, returning"
258 				" ILLEGAL_REQUEST\n");
259 		return TCM_UNSUPPORTED_SCSI_OPCODE;
260 	}
261 	/*
262 	 * This is currently the case for target_core_mod passthrough struct se_cmd
263 	 * ops
264 	 */
265 	if (!sess || !sess->se_tpg)
266 		goto out;
267 	rc = target_check_scsi2_reservation_conflict(cmd);
268 	if (rc == 1)
269 		goto out;
270 
271 	if (rc < 0)
272 		return TCM_RESERVATION_CONFLICT;
273 
274 	tpg = sess->se_tpg;
275 	spin_lock(&dev->dev_reservation_lock);
276 	if (dev->dev_reserved_node_acl &&
277 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
278 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
279 			tpg->se_tpg_tfo->get_fabric_name());
280 		pr_err("Original reserver LUN: %u %s\n",
281 			cmd->se_lun->unpacked_lun,
282 			dev->dev_reserved_node_acl->initiatorname);
283 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
284 			" from %s \n", cmd->se_lun->unpacked_lun,
285 			cmd->se_deve->mapped_lun,
286 			sess->se_node_acl->initiatorname);
287 		ret = TCM_RESERVATION_CONFLICT;
288 		goto out_unlock;
289 	}
290 
291 	dev->dev_reserved_node_acl = sess->se_node_acl;
292 	dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS;
293 	if (sess->sess_bin_isid != 0) {
294 		dev->dev_res_bin_isid = sess->sess_bin_isid;
295 		dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS_WITH_ISID;
296 	}
297 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
298 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
299 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
300 		sess->se_node_acl->initiatorname);
301 
302 out_unlock:
303 	spin_unlock(&dev->dev_reservation_lock);
304 out:
305 	if (!ret)
306 		target_complete_cmd(cmd, GOOD);
307 	return ret;
308 }
309 
310 
311 /*
312  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
313  *
314  * This function is called by those initiator ports who are *NOT*
315  * the active PR reservation holder when a reservation is present.
316  */
317 static int core_scsi3_pr_seq_non_holder(
318 	struct se_cmd *cmd,
319 	u32 pr_reg_type)
320 {
321 	unsigned char *cdb = cmd->t_task_cdb;
322 	struct se_dev_entry *se_deve;
323 	struct se_session *se_sess = cmd->se_sess;
324 	int other_cdb = 0, ignore_reg;
325 	int registered_nexus = 0, ret = 1; /* Conflict by default */
326 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
327 	int we = 0; /* Write Exclusive */
328 	int legacy = 0; /* Act like a legacy device and return
329 			 * RESERVATION CONFLICT on some CDBs */
330 
331 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
332 	/*
333 	 * Determine if the registration should be ignored due to
334 	 * non-matching ISIDs in target_scsi3_pr_reservation_check().
335 	 */
336 	ignore_reg = (pr_reg_type & 0x80000000);
337 	if (ignore_reg)
338 		pr_reg_type &= ~0x80000000;
339 
340 	switch (pr_reg_type) {
341 	case PR_TYPE_WRITE_EXCLUSIVE:
342 		we = 1;
343 	case PR_TYPE_EXCLUSIVE_ACCESS:
344 		/*
345 		 * Some commands are only allowed for the persistent reservation
346 		 * holder.
347 		 */
348 		if ((se_deve->def_pr_registered) && !(ignore_reg))
349 			registered_nexus = 1;
350 		break;
351 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
352 		we = 1;
353 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
354 		/*
355 		 * Some commands are only allowed for registered I_T Nexuses.
356 		 */
357 		reg_only = 1;
358 		if ((se_deve->def_pr_registered) && !(ignore_reg))
359 			registered_nexus = 1;
360 		break;
361 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
362 		we = 1;
363 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
364 		/*
365 		 * Each registered I_T Nexus is a reservation holder.
366 		 */
367 		all_reg = 1;
368 		if ((se_deve->def_pr_registered) && !(ignore_reg))
369 			registered_nexus = 1;
370 		break;
371 	default:
372 		return -EINVAL;
373 	}
374 	/*
375 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
376 	 */
377 	switch (cdb[0]) {
378 	case SECURITY_PROTOCOL_IN:
379 		if (registered_nexus)
380 			return 0;
381 		ret = (we) ? 0 : 1;
382 		break;
383 	case MODE_SENSE:
384 	case MODE_SENSE_10:
385 	case READ_ATTRIBUTE:
386 	case READ_BUFFER:
387 	case RECEIVE_DIAGNOSTIC:
388 		if (legacy) {
389 			ret = 1;
390 			break;
391 		}
392 		if (registered_nexus) {
393 			ret = 0;
394 			break;
395 		}
396 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
397 		break;
398 	case PERSISTENT_RESERVE_OUT:
399 		/*
400 		 * This follows PERSISTENT_RESERVE_OUT service actions that
401 		 * are allowed in the presence of various reservations.
402 		 * See spc4r17, table 46
403 		 */
404 		switch (cdb[1] & 0x1f) {
405 		case PRO_CLEAR:
406 		case PRO_PREEMPT:
407 		case PRO_PREEMPT_AND_ABORT:
408 			ret = (registered_nexus) ? 0 : 1;
409 			break;
410 		case PRO_REGISTER:
411 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
412 			ret = 0;
413 			break;
414 		case PRO_REGISTER_AND_MOVE:
415 		case PRO_RESERVE:
416 			ret = 1;
417 			break;
418 		case PRO_RELEASE:
419 			ret = (registered_nexus) ? 0 : 1;
420 			break;
421 		default:
422 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
423 				" action: 0x%02x\n", cdb[1] & 0x1f);
424 			return -EINVAL;
425 		}
426 		break;
427 	case RELEASE:
428 	case RELEASE_10:
429 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
430 		ret = 0;
431 		break;
432 	case RESERVE:
433 	case RESERVE_10:
434 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
435 		ret = 0;
436 		break;
437 	case TEST_UNIT_READY:
438 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
439 		break;
440 	case MAINTENANCE_IN:
441 		switch (cdb[1] & 0x1f) {
442 		case MI_MANAGEMENT_PROTOCOL_IN:
443 			if (registered_nexus) {
444 				ret = 0;
445 				break;
446 			}
447 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
448 			break;
449 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
450 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
451 			if (legacy) {
452 				ret = 1;
453 				break;
454 			}
455 			if (registered_nexus) {
456 				ret = 0;
457 				break;
458 			}
459 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
460 			break;
461 		case MI_REPORT_ALIASES:
462 		case MI_REPORT_IDENTIFYING_INFORMATION:
463 		case MI_REPORT_PRIORITY:
464 		case MI_REPORT_TARGET_PGS:
465 		case MI_REPORT_TIMESTAMP:
466 			ret = 0; /* Allowed */
467 			break;
468 		default:
469 			pr_err("Unknown MI Service Action: 0x%02x\n",
470 				(cdb[1] & 0x1f));
471 			return -EINVAL;
472 		}
473 		break;
474 	case ACCESS_CONTROL_IN:
475 	case ACCESS_CONTROL_OUT:
476 	case INQUIRY:
477 	case LOG_SENSE:
478 	case SERVICE_ACTION_IN_12:
479 	case REPORT_LUNS:
480 	case REQUEST_SENSE:
481 	case PERSISTENT_RESERVE_IN:
482 		ret = 0; /*/ Allowed CDBs */
483 		break;
484 	default:
485 		other_cdb = 1;
486 		break;
487 	}
488 	/*
489 	 * Case where the CDB is explicitly allowed in the above switch
490 	 * statement.
491 	 */
492 	if (!ret && !other_cdb) {
493 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
494 			" reservation holder\n", cdb[0],
495 			core_scsi3_pr_dump_type(pr_reg_type));
496 
497 		return ret;
498 	}
499 	/*
500 	 * Check if write exclusive initiator ports *NOT* holding the
501 	 * WRITE_EXCLUSIVE_* reservation.
502 	 */
503 	if (we && !registered_nexus) {
504 		if (cmd->data_direction == DMA_TO_DEVICE) {
505 			/*
506 			 * Conflict for write exclusive
507 			 */
508 			pr_debug("%s Conflict for unregistered nexus"
509 				" %s CDB: 0x%02x to %s reservation\n",
510 				transport_dump_cmd_direction(cmd),
511 				se_sess->se_node_acl->initiatorname, cdb[0],
512 				core_scsi3_pr_dump_type(pr_reg_type));
513 			return 1;
514 		} else {
515 			/*
516 			 * Allow non WRITE CDBs for all Write Exclusive
517 			 * PR TYPEs to pass for registered and
518 			 * non-registered_nexuxes NOT holding the reservation.
519 			 *
520 			 * We only make noise for the unregisterd nexuses,
521 			 * as we expect registered non-reservation holding
522 			 * nexuses to issue CDBs.
523 			 */
524 
525 			if (!registered_nexus) {
526 				pr_debug("Allowing implicit CDB: 0x%02x"
527 					" for %s reservation on unregistered"
528 					" nexus\n", cdb[0],
529 					core_scsi3_pr_dump_type(pr_reg_type));
530 			}
531 
532 			return 0;
533 		}
534 	} else if ((reg_only) || (all_reg)) {
535 		if (registered_nexus) {
536 			/*
537 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
538 			 * allow commands from registered nexuses.
539 			 */
540 
541 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
542 				" reservation\n", cdb[0],
543 				core_scsi3_pr_dump_type(pr_reg_type));
544 
545 			return 0;
546 		}
547        } else if (we && registered_nexus) {
548                /*
549                 * Reads are allowed for Write Exclusive locks
550                 * from all registrants.
551                 */
552                if (cmd->data_direction == DMA_FROM_DEVICE) {
553                        pr_debug("Allowing READ CDB: 0x%02x for %s"
554                                " reservation\n", cdb[0],
555                                core_scsi3_pr_dump_type(pr_reg_type));
556 
557                        return 0;
558                }
559 	}
560 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
561 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
562 		(registered_nexus) ? "" : "un",
563 		se_sess->se_node_acl->initiatorname, cdb[0],
564 		core_scsi3_pr_dump_type(pr_reg_type));
565 
566 	return 1; /* Conflict by default */
567 }
568 
569 static sense_reason_t
570 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
571 {
572 	struct se_device *dev = cmd->se_dev;
573 	struct se_session *sess = cmd->se_sess;
574 	u32 pr_reg_type;
575 
576 	if (!dev->dev_pr_res_holder)
577 		return 0;
578 
579 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
580 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
581 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
582 		goto check_nonholder;
583 
584 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
585 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
586 		    sess->sess_bin_isid) {
587 			pr_reg_type |= 0x80000000;
588 			goto check_nonholder;
589 		}
590 	}
591 
592 	return 0;
593 
594 check_nonholder:
595 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type))
596 		return TCM_RESERVATION_CONFLICT;
597 	return 0;
598 }
599 
600 static u32 core_scsi3_pr_generation(struct se_device *dev)
601 {
602 	u32 prg;
603 
604 	/*
605 	 * PRGeneration field shall contain the value of a 32-bit wrapping
606 	 * counter mainted by the device server.
607 	 *
608 	 * Note that this is done regardless of Active Persist across
609 	 * Target PowerLoss (APTPL)
610 	 *
611 	 * See spc4r17 section 6.3.12 READ_KEYS service action
612 	 */
613 	spin_lock(&dev->dev_reservation_lock);
614 	prg = dev->t10_pr.pr_generation++;
615 	spin_unlock(&dev->dev_reservation_lock);
616 
617 	return prg;
618 }
619 
620 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
621 	struct se_device *dev,
622 	struct se_node_acl *nacl,
623 	struct se_dev_entry *deve,
624 	unsigned char *isid,
625 	u64 sa_res_key,
626 	int all_tg_pt,
627 	int aptpl)
628 {
629 	struct t10_pr_registration *pr_reg;
630 
631 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
632 	if (!pr_reg) {
633 		pr_err("Unable to allocate struct t10_pr_registration\n");
634 		return NULL;
635 	}
636 
637 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
638 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
639 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
640 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
641 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
642 	atomic_set(&pr_reg->pr_res_holders, 0);
643 	pr_reg->pr_reg_nacl = nacl;
644 	pr_reg->pr_reg_deve = deve;
645 	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
646 	pr_reg->pr_aptpl_target_lun = deve->se_lun->unpacked_lun;
647 	pr_reg->pr_res_key = sa_res_key;
648 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
649 	pr_reg->pr_reg_aptpl = aptpl;
650 	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
651 	/*
652 	 * If an ISID value for this SCSI Initiator Port exists,
653 	 * save it to the registration now.
654 	 */
655 	if (isid != NULL) {
656 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
657 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
658 		pr_reg->isid_present_at_reg = 1;
659 	}
660 
661 	return pr_reg;
662 }
663 
664 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
665 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
666 
667 /*
668  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
669  * modes.
670  */
671 static struct t10_pr_registration *__core_scsi3_alloc_registration(
672 	struct se_device *dev,
673 	struct se_node_acl *nacl,
674 	struct se_dev_entry *deve,
675 	unsigned char *isid,
676 	u64 sa_res_key,
677 	int all_tg_pt,
678 	int aptpl)
679 {
680 	struct se_dev_entry *deve_tmp;
681 	struct se_node_acl *nacl_tmp;
682 	struct se_port *port, *port_tmp;
683 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
684 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
685 	int ret;
686 	/*
687 	 * Create a registration for the I_T Nexus upon which the
688 	 * PROUT REGISTER was received.
689 	 */
690 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, deve, isid,
691 			sa_res_key, all_tg_pt, aptpl);
692 	if (!pr_reg)
693 		return NULL;
694 	/*
695 	 * Return pointer to pr_reg for ALL_TG_PT=0
696 	 */
697 	if (!all_tg_pt)
698 		return pr_reg;
699 	/*
700 	 * Create list of matching SCSI Initiator Port registrations
701 	 * for ALL_TG_PT=1
702 	 */
703 	spin_lock(&dev->se_port_lock);
704 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
705 		atomic_inc_mb(&port->sep_tg_pt_ref_cnt);
706 		spin_unlock(&dev->se_port_lock);
707 
708 		spin_lock_bh(&port->sep_alua_lock);
709 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
710 					alua_port_list) {
711 			/*
712 			 * This pointer will be NULL for demo mode MappedLUNs
713 			 * that have not been make explicit via a ConfigFS
714 			 * MappedLUN group for the SCSI Initiator Node ACL.
715 			 */
716 			if (!deve_tmp->se_lun_acl)
717 				continue;
718 
719 			nacl_tmp = deve_tmp->se_lun_acl->se_lun_nacl;
720 			/*
721 			 * Skip the matching struct se_node_acl that is allocated
722 			 * above..
723 			 */
724 			if (nacl == nacl_tmp)
725 				continue;
726 			/*
727 			 * Only perform PR registrations for target ports on
728 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
729 			 * arrived.
730 			 */
731 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
732 				continue;
733 			/*
734 			 * Look for a matching Initiator Node ACL in ASCII format
735 			 */
736 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
737 				continue;
738 
739 			atomic_inc_mb(&deve_tmp->pr_ref_count);
740 			spin_unlock_bh(&port->sep_alua_lock);
741 			/*
742 			 * Grab a configfs group dependency that is released
743 			 * for the exception path at label out: below, or upon
744 			 * completion of adding ALL_TG_PT=1 registrations in
745 			 * __core_scsi3_add_registration()
746 			 */
747 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
748 			if (ret < 0) {
749 				pr_err("core_scsi3_lunacl_depend"
750 						"_item() failed\n");
751 				atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
752 				atomic_dec_mb(&deve_tmp->pr_ref_count);
753 				goto out;
754 			}
755 			/*
756 			 * Located a matching SCSI Initiator Port on a different
757 			 * port, allocate the pr_reg_atp and attach it to the
758 			 * pr_reg->pr_reg_atp_list that will be processed once
759 			 * the original *pr_reg is processed in
760 			 * __core_scsi3_add_registration()
761 			 */
762 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
763 						nacl_tmp, deve_tmp, NULL,
764 						sa_res_key, all_tg_pt, aptpl);
765 			if (!pr_reg_atp) {
766 				atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
767 				atomic_dec_mb(&deve_tmp->pr_ref_count);
768 				core_scsi3_lunacl_undepend_item(deve_tmp);
769 				goto out;
770 			}
771 
772 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
773 				      &pr_reg->pr_reg_atp_list);
774 			spin_lock_bh(&port->sep_alua_lock);
775 		}
776 		spin_unlock_bh(&port->sep_alua_lock);
777 
778 		spin_lock(&dev->se_port_lock);
779 		atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
780 	}
781 	spin_unlock(&dev->se_port_lock);
782 
783 	return pr_reg;
784 out:
785 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
786 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
787 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
788 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
789 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
790 	}
791 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
792 	return NULL;
793 }
794 
795 int core_scsi3_alloc_aptpl_registration(
796 	struct t10_reservation *pr_tmpl,
797 	u64 sa_res_key,
798 	unsigned char *i_port,
799 	unsigned char *isid,
800 	u32 mapped_lun,
801 	unsigned char *t_port,
802 	u16 tpgt,
803 	u32 target_lun,
804 	int res_holder,
805 	int all_tg_pt,
806 	u8 type)
807 {
808 	struct t10_pr_registration *pr_reg;
809 
810 	if (!i_port || !t_port || !sa_res_key) {
811 		pr_err("Illegal parameters for APTPL registration\n");
812 		return -EINVAL;
813 	}
814 
815 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
816 	if (!pr_reg) {
817 		pr_err("Unable to allocate struct t10_pr_registration\n");
818 		return -ENOMEM;
819 	}
820 
821 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
822 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
823 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
824 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
825 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
826 	atomic_set(&pr_reg->pr_res_holders, 0);
827 	pr_reg->pr_reg_nacl = NULL;
828 	pr_reg->pr_reg_deve = NULL;
829 	pr_reg->pr_res_mapped_lun = mapped_lun;
830 	pr_reg->pr_aptpl_target_lun = target_lun;
831 	pr_reg->pr_res_key = sa_res_key;
832 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
833 	pr_reg->pr_reg_aptpl = 1;
834 	pr_reg->pr_reg_tg_pt_lun = NULL;
835 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
836 	pr_reg->pr_res_type = type;
837 	/*
838 	 * If an ISID value had been saved in APTPL metadata for this
839 	 * SCSI Initiator Port, restore it now.
840 	 */
841 	if (isid != NULL) {
842 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
843 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
844 		pr_reg->isid_present_at_reg = 1;
845 	}
846 	/*
847 	 * Copy the i_port and t_port information from caller.
848 	 */
849 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
850 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
851 	pr_reg->pr_reg_tpgt = tpgt;
852 	/*
853 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
854 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
855 	 * the Initiator Node LUN ACL from the fabric module is created for
856 	 * this registration.
857 	 */
858 	pr_reg->pr_res_holder = res_holder;
859 
860 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
861 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
862 			" metadata\n", (res_holder) ? "+reservation" : "");
863 	return 0;
864 }
865 
866 static void core_scsi3_aptpl_reserve(
867 	struct se_device *dev,
868 	struct se_portal_group *tpg,
869 	struct se_node_acl *node_acl,
870 	struct t10_pr_registration *pr_reg)
871 {
872 	char i_buf[PR_REG_ISID_ID_LEN];
873 
874 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
875 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
876 
877 	spin_lock(&dev->dev_reservation_lock);
878 	dev->dev_pr_res_holder = pr_reg;
879 	spin_unlock(&dev->dev_reservation_lock);
880 
881 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
882 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
883 		tpg->se_tpg_tfo->get_fabric_name(),
884 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
885 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
886 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
887 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
888 		i_buf);
889 }
890 
891 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
892 				struct t10_pr_registration *, enum register_type, int);
893 
894 static int __core_scsi3_check_aptpl_registration(
895 	struct se_device *dev,
896 	struct se_portal_group *tpg,
897 	struct se_lun *lun,
898 	u32 target_lun,
899 	struct se_node_acl *nacl,
900 	struct se_dev_entry *deve)
901 {
902 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
903 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
904 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
905 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
906 	u16 tpgt;
907 
908 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
909 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
910 	/*
911 	 * Copy Initiator Port information from struct se_node_acl
912 	 */
913 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
914 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
915 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
916 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
917 	/*
918 	 * Look for the matching registrations+reservation from those
919 	 * created from APTPL metadata.  Note that multiple registrations
920 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
921 	 * TransportIDs.
922 	 */
923 	spin_lock(&pr_tmpl->aptpl_reg_lock);
924 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
925 				pr_reg_aptpl_list) {
926 
927 		if (!strcmp(pr_reg->pr_iport, i_port) &&
928 		     (pr_reg->pr_res_mapped_lun == deve->mapped_lun) &&
929 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
930 		     (pr_reg->pr_reg_tpgt == tpgt) &&
931 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
932 
933 			pr_reg->pr_reg_nacl = nacl;
934 			pr_reg->pr_reg_deve = deve;
935 			pr_reg->pr_reg_tg_pt_lun = lun;
936 
937 			list_del(&pr_reg->pr_reg_aptpl_list);
938 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
939 			/*
940 			 * At this point all of the pointers in *pr_reg will
941 			 * be setup, so go ahead and add the registration.
942 			 */
943 
944 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
945 			/*
946 			 * If this registration is the reservation holder,
947 			 * make that happen now..
948 			 */
949 			if (pr_reg->pr_res_holder)
950 				core_scsi3_aptpl_reserve(dev, tpg,
951 						nacl, pr_reg);
952 			/*
953 			 * Reenable pr_aptpl_active to accept new metadata
954 			 * updates once the SCSI device is active again..
955 			 */
956 			spin_lock(&pr_tmpl->aptpl_reg_lock);
957 			pr_tmpl->pr_aptpl_active = 1;
958 		}
959 	}
960 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
961 
962 	return 0;
963 }
964 
965 int core_scsi3_check_aptpl_registration(
966 	struct se_device *dev,
967 	struct se_portal_group *tpg,
968 	struct se_lun *lun,
969 	struct se_node_acl *nacl,
970 	u32 mapped_lun)
971 {
972 	struct se_dev_entry *deve = nacl->device_list[mapped_lun];
973 
974 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
975 		return 0;
976 
977 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
978 				lun->unpacked_lun, nacl, deve);
979 }
980 
981 static void __core_scsi3_dump_registration(
982 	const struct target_core_fabric_ops *tfo,
983 	struct se_device *dev,
984 	struct se_node_acl *nacl,
985 	struct t10_pr_registration *pr_reg,
986 	enum register_type register_type)
987 {
988 	struct se_portal_group *se_tpg = nacl->se_tpg;
989 	char i_buf[PR_REG_ISID_ID_LEN];
990 
991 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
992 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
993 
994 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
995 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == REGISTER_AND_MOVE) ?
996 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
997 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
998 		i_buf);
999 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1000 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
1001 		tfo->tpg_get_tag(se_tpg));
1002 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1003 		" Port(s)\n",  tfo->get_fabric_name(),
1004 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1005 		dev->transport->name);
1006 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1007 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
1008 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1009 		pr_reg->pr_reg_aptpl);
1010 }
1011 
1012 /*
1013  * this function can be called with struct se_device->dev_reservation_lock
1014  * when register_move = 1
1015  */
1016 static void __core_scsi3_add_registration(
1017 	struct se_device *dev,
1018 	struct se_node_acl *nacl,
1019 	struct t10_pr_registration *pr_reg,
1020 	enum register_type register_type,
1021 	int register_move)
1022 {
1023 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1024 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1025 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1026 
1027 	/*
1028 	 * Increment PRgeneration counter for struct se_device upon a successful
1029 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1030 	 *
1031 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1032 	 * action, the struct se_device->dev_reservation_lock will already be held,
1033 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1034 	 * for the REGISTER.
1035 	 */
1036 	pr_reg->pr_res_generation = (register_move) ?
1037 			dev->t10_pr.pr_generation++ :
1038 			core_scsi3_pr_generation(dev);
1039 
1040 	spin_lock(&pr_tmpl->registration_lock);
1041 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1042 	pr_reg->pr_reg_deve->def_pr_registered = 1;
1043 
1044 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1045 	spin_unlock(&pr_tmpl->registration_lock);
1046 	/*
1047 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1048 	 */
1049 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1050 		return;
1051 	/*
1052 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1053 	 * allocated in __core_scsi3_alloc_registration()
1054 	 */
1055 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1056 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1057 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1058 
1059 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1060 
1061 		spin_lock(&pr_tmpl->registration_lock);
1062 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1063 			      &pr_tmpl->registration_list);
1064 		pr_reg_tmp->pr_reg_deve->def_pr_registered = 1;
1065 
1066 		__core_scsi3_dump_registration(tfo, dev,
1067 				pr_reg_tmp->pr_reg_nacl, pr_reg_tmp,
1068 				register_type);
1069 		spin_unlock(&pr_tmpl->registration_lock);
1070 		/*
1071 		 * Drop configfs group dependency reference from
1072 		 * __core_scsi3_alloc_registration()
1073 		 */
1074 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1075 	}
1076 }
1077 
1078 static int core_scsi3_alloc_registration(
1079 	struct se_device *dev,
1080 	struct se_node_acl *nacl,
1081 	struct se_dev_entry *deve,
1082 	unsigned char *isid,
1083 	u64 sa_res_key,
1084 	int all_tg_pt,
1085 	int aptpl,
1086 	enum register_type register_type,
1087 	int register_move)
1088 {
1089 	struct t10_pr_registration *pr_reg;
1090 
1091 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, deve, isid,
1092 			sa_res_key, all_tg_pt, aptpl);
1093 	if (!pr_reg)
1094 		return -EPERM;
1095 
1096 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1097 			register_type, register_move);
1098 	return 0;
1099 }
1100 
1101 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1102 	struct se_device *dev,
1103 	struct se_node_acl *nacl,
1104 	unsigned char *isid)
1105 {
1106 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1107 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1108 	struct se_portal_group *tpg;
1109 
1110 	spin_lock(&pr_tmpl->registration_lock);
1111 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1112 			&pr_tmpl->registration_list, pr_reg_list) {
1113 		/*
1114 		 * First look for a matching struct se_node_acl
1115 		 */
1116 		if (pr_reg->pr_reg_nacl != nacl)
1117 			continue;
1118 
1119 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1120 		/*
1121 		 * If this registration does NOT contain a fabric provided
1122 		 * ISID, then we have found a match.
1123 		 */
1124 		if (!pr_reg->isid_present_at_reg) {
1125 			/*
1126 			 * Determine if this SCSI device server requires that
1127 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1128 			 * for fabric modules (iSCSI) requiring them.
1129 			 */
1130 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1131 				if (dev->dev_attrib.enforce_pr_isids)
1132 					continue;
1133 			}
1134 			atomic_inc_mb(&pr_reg->pr_res_holders);
1135 			spin_unlock(&pr_tmpl->registration_lock);
1136 			return pr_reg;
1137 		}
1138 		/*
1139 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1140 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1141 		 * matching ISID to be provided by the local SCSI Initiator Port.
1142 		 */
1143 		if (!isid)
1144 			continue;
1145 		if (strcmp(isid, pr_reg->pr_reg_isid))
1146 			continue;
1147 
1148 		atomic_inc_mb(&pr_reg->pr_res_holders);
1149 		spin_unlock(&pr_tmpl->registration_lock);
1150 		return pr_reg;
1151 	}
1152 	spin_unlock(&pr_tmpl->registration_lock);
1153 
1154 	return NULL;
1155 }
1156 
1157 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1158 	struct se_device *dev,
1159 	struct se_node_acl *nacl,
1160 	struct se_session *sess)
1161 {
1162 	struct se_portal_group *tpg = nacl->se_tpg;
1163 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1164 
1165 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1166 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1167 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1168 					PR_REG_ISID_LEN);
1169 		isid_ptr = &buf[0];
1170 	}
1171 
1172 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1173 }
1174 
1175 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1176 {
1177 	atomic_dec_mb(&pr_reg->pr_res_holders);
1178 }
1179 
1180 static int core_scsi3_check_implicit_release(
1181 	struct se_device *dev,
1182 	struct t10_pr_registration *pr_reg)
1183 {
1184 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1185 	struct t10_pr_registration *pr_res_holder;
1186 	int ret = 0;
1187 
1188 	spin_lock(&dev->dev_reservation_lock);
1189 	pr_res_holder = dev->dev_pr_res_holder;
1190 	if (!pr_res_holder) {
1191 		spin_unlock(&dev->dev_reservation_lock);
1192 		return ret;
1193 	}
1194 	if (pr_res_holder == pr_reg) {
1195 		/*
1196 		 * Perform an implicit RELEASE if the registration that
1197 		 * is being released is holding the reservation.
1198 		 *
1199 		 * From spc4r17, section 5.7.11.1:
1200 		 *
1201 		 * e) If the I_T nexus is the persistent reservation holder
1202 		 *    and the persistent reservation is not an all registrants
1203 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1204 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1205 		 *    service action with the SERVICE ACTION RESERVATION KEY
1206 		 *    field set to zero (see 5.7.11.3).
1207 		 */
1208 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1209 		ret = 1;
1210 		/*
1211 		 * For 'All Registrants' reservation types, all existing
1212 		 * registrations are still processed as reservation holders
1213 		 * in core_scsi3_pr_seq_non_holder() after the initial
1214 		 * reservation holder is implicitly released here.
1215 		 */
1216 	} else if (pr_reg->pr_reg_all_tg_pt &&
1217 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1218 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1219 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1220 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1221 			" UNREGISTER while existing reservation with matching"
1222 			" key 0x%016Lx is present from another SCSI Initiator"
1223 			" Port\n", pr_reg->pr_res_key);
1224 		ret = -EPERM;
1225 	}
1226 	spin_unlock(&dev->dev_reservation_lock);
1227 
1228 	return ret;
1229 }
1230 
1231 /*
1232  * Called with struct t10_reservation->registration_lock held.
1233  */
1234 static void __core_scsi3_free_registration(
1235 	struct se_device *dev,
1236 	struct t10_pr_registration *pr_reg,
1237 	struct list_head *preempt_and_abort_list,
1238 	int dec_holders)
1239 	__releases(&pr_tmpl->registration_lock)
1240 	__acquires(&pr_tmpl->registration_lock)
1241 {
1242 	const struct target_core_fabric_ops *tfo =
1243 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1244 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1245 	char i_buf[PR_REG_ISID_ID_LEN];
1246 
1247 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1248 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1249 
1250 	pr_reg->pr_reg_deve->def_pr_registered = 0;
1251 	pr_reg->pr_reg_deve->pr_res_key = 0;
1252 	if (!list_empty(&pr_reg->pr_reg_list))
1253 		list_del(&pr_reg->pr_reg_list);
1254 	/*
1255 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1256 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1257 	 */
1258 	if (dec_holders)
1259 		core_scsi3_put_pr_reg(pr_reg);
1260 	/*
1261 	 * Wait until all reference from any other I_T nexuses for this
1262 	 * *pr_reg have been released.  Because list_del() is called above,
1263 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1264 	 * count back to zero, and we release *pr_reg.
1265 	 */
1266 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1267 		spin_unlock(&pr_tmpl->registration_lock);
1268 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1269 				tfo->get_fabric_name());
1270 		cpu_relax();
1271 		spin_lock(&pr_tmpl->registration_lock);
1272 	}
1273 
1274 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1275 		" Node: %s%s\n", tfo->get_fabric_name(),
1276 		pr_reg->pr_reg_nacl->initiatorname,
1277 		i_buf);
1278 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1279 		" Port(s)\n", tfo->get_fabric_name(),
1280 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1281 		dev->transport->name);
1282 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1283 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1284 		pr_reg->pr_res_generation);
1285 
1286 	if (!preempt_and_abort_list) {
1287 		pr_reg->pr_reg_deve = NULL;
1288 		pr_reg->pr_reg_nacl = NULL;
1289 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1290 		return;
1291 	}
1292 	/*
1293 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1294 	 * are released once the ABORT_TASK_SET has completed..
1295 	 */
1296 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1297 }
1298 
1299 void core_scsi3_free_pr_reg_from_nacl(
1300 	struct se_device *dev,
1301 	struct se_node_acl *nacl)
1302 {
1303 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1304 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1305 	bool free_reg = false;
1306 	/*
1307 	 * If the passed se_node_acl matches the reservation holder,
1308 	 * release the reservation.
1309 	 */
1310 	spin_lock(&dev->dev_reservation_lock);
1311 	pr_res_holder = dev->dev_pr_res_holder;
1312 	if ((pr_res_holder != NULL) &&
1313 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1314 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1315 		free_reg = true;
1316 	}
1317 	spin_unlock(&dev->dev_reservation_lock);
1318 	/*
1319 	 * Release any registration associated with the struct se_node_acl.
1320 	 */
1321 	spin_lock(&pr_tmpl->registration_lock);
1322 	if (pr_res_holder && free_reg)
1323 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1324 
1325 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1326 			&pr_tmpl->registration_list, pr_reg_list) {
1327 
1328 		if (pr_reg->pr_reg_nacl != nacl)
1329 			continue;
1330 
1331 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1332 	}
1333 	spin_unlock(&pr_tmpl->registration_lock);
1334 }
1335 
1336 void core_scsi3_free_all_registrations(
1337 	struct se_device *dev)
1338 {
1339 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1340 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1341 
1342 	spin_lock(&dev->dev_reservation_lock);
1343 	pr_res_holder = dev->dev_pr_res_holder;
1344 	if (pr_res_holder != NULL) {
1345 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1346 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1347 						  pr_res_holder, 0, 0);
1348 	}
1349 	spin_unlock(&dev->dev_reservation_lock);
1350 
1351 	spin_lock(&pr_tmpl->registration_lock);
1352 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1353 			&pr_tmpl->registration_list, pr_reg_list) {
1354 
1355 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1356 	}
1357 	spin_unlock(&pr_tmpl->registration_lock);
1358 
1359 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1360 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1361 				pr_reg_aptpl_list) {
1362 		list_del(&pr_reg->pr_reg_aptpl_list);
1363 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1364 	}
1365 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1366 }
1367 
1368 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1369 {
1370 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1371 			&tpg->tpg_group.cg_item);
1372 }
1373 
1374 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1375 {
1376 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1377 			&tpg->tpg_group.cg_item);
1378 
1379 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1380 }
1381 
1382 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1383 {
1384 	struct se_portal_group *tpg = nacl->se_tpg;
1385 
1386 	if (nacl->dynamic_node_acl)
1387 		return 0;
1388 
1389 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1390 			&nacl->acl_group.cg_item);
1391 }
1392 
1393 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1394 {
1395 	struct se_portal_group *tpg = nacl->se_tpg;
1396 
1397 	if (nacl->dynamic_node_acl) {
1398 		atomic_dec_mb(&nacl->acl_pr_ref_count);
1399 		return;
1400 	}
1401 
1402 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1403 			&nacl->acl_group.cg_item);
1404 
1405 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1406 }
1407 
1408 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1409 {
1410 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1411 	struct se_node_acl *nacl;
1412 	struct se_portal_group *tpg;
1413 	/*
1414 	 * For nacl->dynamic_node_acl=1
1415 	 */
1416 	if (!lun_acl)
1417 		return 0;
1418 
1419 	nacl = lun_acl->se_lun_nacl;
1420 	tpg = nacl->se_tpg;
1421 
1422 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1423 			&lun_acl->se_lun_group.cg_item);
1424 }
1425 
1426 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1427 {
1428 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1429 	struct se_node_acl *nacl;
1430 	struct se_portal_group *tpg;
1431 	/*
1432 	 * For nacl->dynamic_node_acl=1
1433 	 */
1434 	if (!lun_acl) {
1435 		atomic_dec_mb(&se_deve->pr_ref_count);
1436 		return;
1437 	}
1438 	nacl = lun_acl->se_lun_nacl;
1439 	tpg = nacl->se_tpg;
1440 
1441 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1442 			&lun_acl->se_lun_group.cg_item);
1443 
1444 	atomic_dec_mb(&se_deve->pr_ref_count);
1445 }
1446 
1447 static sense_reason_t
1448 core_scsi3_decode_spec_i_port(
1449 	struct se_cmd *cmd,
1450 	struct se_portal_group *tpg,
1451 	unsigned char *l_isid,
1452 	u64 sa_res_key,
1453 	int all_tg_pt,
1454 	int aptpl)
1455 {
1456 	struct se_device *dev = cmd->se_dev;
1457 	struct se_port *tmp_port;
1458 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1459 	struct se_session *se_sess = cmd->se_sess;
1460 	struct se_node_acl *dest_node_acl = NULL;
1461 	struct se_dev_entry *dest_se_deve = NULL, *local_se_deve;
1462 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1463 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1464 	LIST_HEAD(tid_dest_list);
1465 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1466 	const struct target_core_fabric_ops *tmp_tf_ops;
1467 	unsigned char *buf;
1468 	unsigned char *ptr, *i_str = NULL, proto_ident, tmp_proto_ident;
1469 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1470 	sense_reason_t ret;
1471 	u32 tpdl, tid_len = 0;
1472 	int dest_local_nexus;
1473 	u32 dest_rtpi = 0;
1474 
1475 	local_se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
1476 	/*
1477 	 * Allocate a struct pr_transport_id_holder and setup the
1478 	 * local_node_acl and local_se_deve pointers and add to
1479 	 * struct list_head tid_dest_list for add registration
1480 	 * processing in the loop of tid_dest_list below.
1481 	 */
1482 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1483 	if (!tidh_new) {
1484 		pr_err("Unable to allocate tidh_new\n");
1485 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1486 	}
1487 	INIT_LIST_HEAD(&tidh_new->dest_list);
1488 	tidh_new->dest_tpg = tpg;
1489 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1490 	tidh_new->dest_se_deve = local_se_deve;
1491 
1492 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1493 				se_sess->se_node_acl, local_se_deve, l_isid,
1494 				sa_res_key, all_tg_pt, aptpl);
1495 	if (!local_pr_reg) {
1496 		kfree(tidh_new);
1497 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1498 	}
1499 	tidh_new->dest_pr_reg = local_pr_reg;
1500 	/*
1501 	 * The local I_T nexus does not hold any configfs dependances,
1502 	 * so we set tid_h->dest_local_nexus=1 to prevent the
1503 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1504 	 */
1505 	tidh_new->dest_local_nexus = 1;
1506 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1507 
1508 	if (cmd->data_length < 28) {
1509 		pr_warn("SPC-PR: Received PR OUT parameter list"
1510 			" length too small: %u\n", cmd->data_length);
1511 		ret = TCM_INVALID_PARAMETER_LIST;
1512 		goto out;
1513 	}
1514 
1515 	buf = transport_kmap_data_sg(cmd);
1516 	if (!buf) {
1517 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1518 		goto out;
1519 	}
1520 
1521 	/*
1522 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1523 	 * first extract TransportID Parameter Data Length, and make sure
1524 	 * the value matches up to the SCSI expected data transfer length.
1525 	 */
1526 	tpdl = (buf[24] & 0xff) << 24;
1527 	tpdl |= (buf[25] & 0xff) << 16;
1528 	tpdl |= (buf[26] & 0xff) << 8;
1529 	tpdl |= buf[27] & 0xff;
1530 
1531 	if ((tpdl + 28) != cmd->data_length) {
1532 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1533 			" does not equal CDB data_length: %u\n", tpdl,
1534 			cmd->data_length);
1535 		ret = TCM_INVALID_PARAMETER_LIST;
1536 		goto out_unmap;
1537 	}
1538 	/*
1539 	 * Start processing the received transport IDs using the
1540 	 * receiving I_T Nexus portal's fabric dependent methods to
1541 	 * obtain the SCSI Initiator Port/Device Identifiers.
1542 	 */
1543 	ptr = &buf[28];
1544 
1545 	while (tpdl > 0) {
1546 		proto_ident = (ptr[0] & 0x0f);
1547 		dest_tpg = NULL;
1548 
1549 		spin_lock(&dev->se_port_lock);
1550 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1551 			tmp_tpg = tmp_port->sep_tpg;
1552 			if (!tmp_tpg)
1553 				continue;
1554 			tmp_tf_ops = tmp_tpg->se_tpg_tfo;
1555 			if (!tmp_tf_ops)
1556 				continue;
1557 			if (!tmp_tf_ops->get_fabric_proto_ident ||
1558 			    !tmp_tf_ops->tpg_parse_pr_out_transport_id)
1559 				continue;
1560 			/*
1561 			 * Look for the matching proto_ident provided by
1562 			 * the received TransportID
1563 			 */
1564 			tmp_proto_ident = tmp_tf_ops->get_fabric_proto_ident(tmp_tpg);
1565 			if (tmp_proto_ident != proto_ident)
1566 				continue;
1567 			dest_rtpi = tmp_port->sep_rtpi;
1568 
1569 			i_str = tmp_tf_ops->tpg_parse_pr_out_transport_id(
1570 					tmp_tpg, (const char *)ptr, &tid_len,
1571 					&iport_ptr);
1572 			if (!i_str)
1573 				continue;
1574 
1575 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1576 			spin_unlock(&dev->se_port_lock);
1577 
1578 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1579 				pr_err(" core_scsi3_tpg_depend_item()"
1580 					" for tmp_tpg\n");
1581 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1582 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1583 				goto out_unmap;
1584 			}
1585 			/*
1586 			 * Locate the destination initiator ACL to be registered
1587 			 * from the decoded fabric module specific TransportID
1588 			 * at *i_str.
1589 			 */
1590 			spin_lock_irq(&tmp_tpg->acl_node_lock);
1591 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1592 						tmp_tpg, i_str);
1593 			if (dest_node_acl)
1594 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1595 			spin_unlock_irq(&tmp_tpg->acl_node_lock);
1596 
1597 			if (!dest_node_acl) {
1598 				core_scsi3_tpg_undepend_item(tmp_tpg);
1599 				spin_lock(&dev->se_port_lock);
1600 				continue;
1601 			}
1602 
1603 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1604 				pr_err("configfs_depend_item() failed"
1605 					" for dest_node_acl->acl_group\n");
1606 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1607 				core_scsi3_tpg_undepend_item(tmp_tpg);
1608 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1609 				goto out_unmap;
1610 			}
1611 
1612 			dest_tpg = tmp_tpg;
1613 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1614 				" %s Port RTPI: %hu\n",
1615 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1616 				dest_node_acl->initiatorname, dest_rtpi);
1617 
1618 			spin_lock(&dev->se_port_lock);
1619 			break;
1620 		}
1621 		spin_unlock(&dev->se_port_lock);
1622 
1623 		if (!dest_tpg) {
1624 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1625 					" dest_tpg\n");
1626 			ret = TCM_INVALID_PARAMETER_LIST;
1627 			goto out_unmap;
1628 		}
1629 
1630 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1631 			" tid_len: %d for %s + %s\n",
1632 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1633 			tpdl, tid_len, i_str, iport_ptr);
1634 
1635 		if (tid_len > tpdl) {
1636 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1637 				" %u for Transport ID: %s\n", tid_len, ptr);
1638 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1639 			core_scsi3_tpg_undepend_item(dest_tpg);
1640 			ret = TCM_INVALID_PARAMETER_LIST;
1641 			goto out_unmap;
1642 		}
1643 		/*
1644 		 * Locate the desintation struct se_dev_entry pointer for matching
1645 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1646 		 * Target Port.
1647 		 */
1648 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1649 					dest_rtpi);
1650 		if (!dest_se_deve) {
1651 			pr_err("Unable to locate %s dest_se_deve"
1652 				" from destination RTPI: %hu\n",
1653 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1654 				dest_rtpi);
1655 
1656 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1657 			core_scsi3_tpg_undepend_item(dest_tpg);
1658 			ret = TCM_INVALID_PARAMETER_LIST;
1659 			goto out_unmap;
1660 		}
1661 
1662 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1663 			pr_err("core_scsi3_lunacl_depend_item()"
1664 					" failed\n");
1665 			atomic_dec_mb(&dest_se_deve->pr_ref_count);
1666 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1667 			core_scsi3_tpg_undepend_item(dest_tpg);
1668 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1669 			goto out_unmap;
1670 		}
1671 
1672 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1673 			" dest_se_deve mapped_lun: %u\n",
1674 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1675 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1676 
1677 		/*
1678 		 * Skip any TransportIDs that already have a registration for
1679 		 * this target port.
1680 		 */
1681 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1682 					iport_ptr);
1683 		if (pr_reg_e) {
1684 			core_scsi3_put_pr_reg(pr_reg_e);
1685 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1686 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1687 			core_scsi3_tpg_undepend_item(dest_tpg);
1688 			ptr += tid_len;
1689 			tpdl -= tid_len;
1690 			tid_len = 0;
1691 			continue;
1692 		}
1693 		/*
1694 		 * Allocate a struct pr_transport_id_holder and setup
1695 		 * the dest_node_acl and dest_se_deve pointers for the
1696 		 * loop below.
1697 		 */
1698 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1699 				GFP_KERNEL);
1700 		if (!tidh_new) {
1701 			pr_err("Unable to allocate tidh_new\n");
1702 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1703 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1704 			core_scsi3_tpg_undepend_item(dest_tpg);
1705 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1706 			goto out_unmap;
1707 		}
1708 		INIT_LIST_HEAD(&tidh_new->dest_list);
1709 		tidh_new->dest_tpg = dest_tpg;
1710 		tidh_new->dest_node_acl = dest_node_acl;
1711 		tidh_new->dest_se_deve = dest_se_deve;
1712 
1713 		/*
1714 		 * Allocate, but do NOT add the registration for the
1715 		 * TransportID referenced SCSI Initiator port.  This
1716 		 * done because of the following from spc4r17 in section
1717 		 * 6.14.3 wrt SPEC_I_PT:
1718 		 *
1719 		 * "If a registration fails for any initiator port (e.g., if th
1720 		 * logical unit does not have enough resources available to
1721 		 * hold the registration information), no registrations shall be
1722 		 * made, and the command shall be terminated with
1723 		 * CHECK CONDITION status."
1724 		 *
1725 		 * That means we call __core_scsi3_alloc_registration() here,
1726 		 * and then call __core_scsi3_add_registration() in the
1727 		 * 2nd loop which will never fail.
1728 		 */
1729 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1730 				dest_node_acl, dest_se_deve, iport_ptr,
1731 				sa_res_key, all_tg_pt, aptpl);
1732 		if (!dest_pr_reg) {
1733 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1734 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1735 			core_scsi3_tpg_undepend_item(dest_tpg);
1736 			kfree(tidh_new);
1737 			ret = TCM_INVALID_PARAMETER_LIST;
1738 			goto out_unmap;
1739 		}
1740 		tidh_new->dest_pr_reg = dest_pr_reg;
1741 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1742 
1743 		ptr += tid_len;
1744 		tpdl -= tid_len;
1745 		tid_len = 0;
1746 
1747 	}
1748 
1749 	transport_kunmap_data_sg(cmd);
1750 
1751 	/*
1752 	 * Go ahead and create a registrations from tid_dest_list for the
1753 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1754 	 * and dest_se_deve.
1755 	 *
1756 	 * The SA Reservation Key from the PROUT is set for the
1757 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1758 	 * means that the TransportID Initiator port will be
1759 	 * registered on all of the target ports in the SCSI target device
1760 	 * ALL_TG_PT=0 means the registration will only be for the
1761 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1762 	 * was received.
1763 	 */
1764 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1765 		dest_tpg = tidh->dest_tpg;
1766 		dest_node_acl = tidh->dest_node_acl;
1767 		dest_se_deve = tidh->dest_se_deve;
1768 		dest_pr_reg = tidh->dest_pr_reg;
1769 		dest_local_nexus = tidh->dest_local_nexus;
1770 
1771 		list_del(&tidh->dest_list);
1772 		kfree(tidh);
1773 
1774 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1775 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1776 
1777 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1778 					dest_pr_reg, 0, 0);
1779 
1780 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1781 			" registered Transport ID for Node: %s%s Mapped LUN:"
1782 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1783 			dest_node_acl->initiatorname, i_buf, dest_se_deve->mapped_lun);
1784 
1785 		if (dest_local_nexus)
1786 			continue;
1787 
1788 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1789 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1790 		core_scsi3_tpg_undepend_item(dest_tpg);
1791 	}
1792 
1793 	return 0;
1794 out_unmap:
1795 	transport_kunmap_data_sg(cmd);
1796 out:
1797 	/*
1798 	 * For the failure case, release everything from tid_dest_list
1799 	 * including *dest_pr_reg and the configfs dependances..
1800 	 */
1801 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1802 		dest_tpg = tidh->dest_tpg;
1803 		dest_node_acl = tidh->dest_node_acl;
1804 		dest_se_deve = tidh->dest_se_deve;
1805 		dest_pr_reg = tidh->dest_pr_reg;
1806 		dest_local_nexus = tidh->dest_local_nexus;
1807 
1808 		list_del(&tidh->dest_list);
1809 		kfree(tidh);
1810 		/*
1811 		 * Release any extra ALL_TG_PT=1 registrations for
1812 		 * the SPEC_I_PT=1 case.
1813 		 */
1814 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1815 				&dest_pr_reg->pr_reg_atp_list,
1816 				pr_reg_atp_mem_list) {
1817 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1818 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1819 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1820 		}
1821 
1822 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1823 
1824 		if (dest_local_nexus)
1825 			continue;
1826 
1827 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1828 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1829 		core_scsi3_tpg_undepend_item(dest_tpg);
1830 	}
1831 	return ret;
1832 }
1833 
1834 static int core_scsi3_update_aptpl_buf(
1835 	struct se_device *dev,
1836 	unsigned char *buf,
1837 	u32 pr_aptpl_buf_len)
1838 {
1839 	struct se_lun *lun;
1840 	struct se_portal_group *tpg;
1841 	struct t10_pr_registration *pr_reg;
1842 	unsigned char tmp[512], isid_buf[32];
1843 	ssize_t len = 0;
1844 	int reg_count = 0;
1845 	int ret = 0;
1846 
1847 	spin_lock(&dev->dev_reservation_lock);
1848 	spin_lock(&dev->t10_pr.registration_lock);
1849 	/*
1850 	 * Walk the registration list..
1851 	 */
1852 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1853 			pr_reg_list) {
1854 
1855 		tmp[0] = '\0';
1856 		isid_buf[0] = '\0';
1857 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1858 		lun = pr_reg->pr_reg_tg_pt_lun;
1859 		/*
1860 		 * Write out any ISID value to APTPL metadata that was included
1861 		 * in the original registration.
1862 		 */
1863 		if (pr_reg->isid_present_at_reg)
1864 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1865 					pr_reg->pr_reg_isid);
1866 		/*
1867 		 * Include special metadata if the pr_reg matches the
1868 		 * reservation holder.
1869 		 */
1870 		if (dev->dev_pr_res_holder == pr_reg) {
1871 			snprintf(tmp, 512, "PR_REG_START: %d"
1872 				"\ninitiator_fabric=%s\n"
1873 				"initiator_node=%s\n%s"
1874 				"sa_res_key=%llu\n"
1875 				"res_holder=1\nres_type=%02x\n"
1876 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1877 				"mapped_lun=%u\n", reg_count,
1878 				tpg->se_tpg_tfo->get_fabric_name(),
1879 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1880 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1881 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1882 				pr_reg->pr_res_mapped_lun);
1883 		} else {
1884 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1885 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1886 				"sa_res_key=%llu\nres_holder=0\n"
1887 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1888 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1889 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1890 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1891 				pr_reg->pr_res_mapped_lun);
1892 		}
1893 
1894 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1895 			pr_err("Unable to update renaming APTPL metadata,"
1896 			       " reallocating larger buffer\n");
1897 			ret = -EMSGSIZE;
1898 			goto out;
1899 		}
1900 		len += sprintf(buf+len, "%s", tmp);
1901 
1902 		/*
1903 		 * Include information about the associated SCSI target port.
1904 		 */
1905 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1906 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1907 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1908 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1909 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1910 			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);
1911 
1912 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1913 			pr_err("Unable to update renaming APTPL metadata,"
1914 			       " reallocating larger buffer\n");
1915 			ret = -EMSGSIZE;
1916 			goto out;
1917 		}
1918 		len += sprintf(buf+len, "%s", tmp);
1919 		reg_count++;
1920 	}
1921 
1922 	if (!reg_count)
1923 		len += sprintf(buf+len, "No Registrations or Reservations");
1924 
1925 out:
1926 	spin_unlock(&dev->t10_pr.registration_lock);
1927 	spin_unlock(&dev->dev_reservation_lock);
1928 
1929 	return ret;
1930 }
1931 
1932 static int __core_scsi3_write_aptpl_to_file(
1933 	struct se_device *dev,
1934 	unsigned char *buf)
1935 {
1936 	struct t10_wwn *wwn = &dev->t10_wwn;
1937 	struct file *file;
1938 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1939 	char path[512];
1940 	u32 pr_aptpl_buf_len;
1941 	int ret;
1942 
1943 	memset(path, 0, 512);
1944 
1945 	if (strlen(&wwn->unit_serial[0]) >= 512) {
1946 		pr_err("WWN value for struct se_device does not fit"
1947 			" into path buffer\n");
1948 		return -EMSGSIZE;
1949 	}
1950 
1951 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
1952 	file = filp_open(path, flags, 0600);
1953 	if (IS_ERR(file)) {
1954 		pr_err("filp_open(%s) for APTPL metadata"
1955 			" failed\n", path);
1956 		return PTR_ERR(file);
1957 	}
1958 
1959 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1960 
1961 	ret = kernel_write(file, buf, pr_aptpl_buf_len, 0);
1962 
1963 	if (ret < 0)
1964 		pr_debug("Error writing APTPL metadata file: %s\n", path);
1965 	fput(file);
1966 
1967 	return (ret < 0) ? -EIO : 0;
1968 }
1969 
1970 /*
1971  * Clear the APTPL metadata if APTPL has been disabled, otherwise
1972  * write out the updated metadata to struct file for this SCSI device.
1973  */
1974 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
1975 {
1976 	unsigned char *buf;
1977 	int rc, len = PR_APTPL_BUF_LEN;
1978 
1979 	if (!aptpl) {
1980 		char *null_buf = "No Registrations or Reservations\n";
1981 
1982 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
1983 		dev->t10_pr.pr_aptpl_active = 0;
1984 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
1985 
1986 		if (rc)
1987 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1988 
1989 		return 0;
1990 	}
1991 retry:
1992 	buf = vzalloc(len);
1993 	if (!buf)
1994 		return TCM_OUT_OF_RESOURCES;
1995 
1996 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
1997 	if (rc < 0) {
1998 		vfree(buf);
1999 		len *= 2;
2000 		goto retry;
2001 	}
2002 
2003 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2004 	if (rc != 0) {
2005 		pr_err("SPC-3 PR: Could not update APTPL\n");
2006 		vfree(buf);
2007 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2008 	}
2009 	dev->t10_pr.pr_aptpl_active = 1;
2010 	vfree(buf);
2011 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2012 	return 0;
2013 }
2014 
2015 static sense_reason_t
2016 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2017 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2018 {
2019 	struct se_session *se_sess = cmd->se_sess;
2020 	struct se_device *dev = cmd->se_dev;
2021 	struct se_dev_entry *se_deve;
2022 	struct se_lun *se_lun = cmd->se_lun;
2023 	struct se_portal_group *se_tpg;
2024 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2025 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2026 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2027 	sense_reason_t ret = TCM_NO_SENSE;
2028 	int pr_holder = 0, type;
2029 
2030 	if (!se_sess || !se_lun) {
2031 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2032 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2033 	}
2034 	se_tpg = se_sess->se_tpg;
2035 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2036 
2037 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2038 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2039 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2040 				PR_REG_ISID_LEN);
2041 		isid_ptr = &isid_buf[0];
2042 	}
2043 	/*
2044 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2045 	 */
2046 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2047 	if (!pr_reg) {
2048 		if (res_key) {
2049 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2050 				" for SA REGISTER, returning CONFLICT\n");
2051 			return TCM_RESERVATION_CONFLICT;
2052 		}
2053 		/*
2054 		 * Do nothing but return GOOD status.
2055 		 */
2056 		if (!sa_res_key)
2057 			return 0;
2058 
2059 		if (!spec_i_pt) {
2060 			/*
2061 			 * Perform the Service Action REGISTER on the Initiator
2062 			 * Port Endpoint that the PRO was received from on the
2063 			 * Logical Unit of the SCSI device server.
2064 			 */
2065 			if (core_scsi3_alloc_registration(cmd->se_dev,
2066 					se_sess->se_node_acl, se_deve, isid_ptr,
2067 					sa_res_key, all_tg_pt, aptpl,
2068 					register_type, 0)) {
2069 				pr_err("Unable to allocate"
2070 					" struct t10_pr_registration\n");
2071 				return TCM_INVALID_PARAMETER_LIST;
2072 			}
2073 		} else {
2074 			/*
2075 			 * Register both the Initiator port that received
2076 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2077 			 * TransportID from Parameter list and loop through
2078 			 * fabric dependent parameter list while calling
2079 			 * logic from of core_scsi3_alloc_registration() for
2080 			 * each TransportID provided SCSI Initiator Port/Device
2081 			 */
2082 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2083 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2084 			if (ret != 0)
2085 				return ret;
2086 		}
2087 
2088 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2089 	}
2090 
2091 	/* ok, existing registration */
2092 
2093 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2094 		pr_err("SPC-3 PR REGISTER: Received"
2095 		       " res_key: 0x%016Lx does not match"
2096 		       " existing SA REGISTER res_key:"
2097 		       " 0x%016Lx\n", res_key,
2098 		       pr_reg->pr_res_key);
2099 		ret = TCM_RESERVATION_CONFLICT;
2100 		goto out;
2101 	}
2102 
2103 	if (spec_i_pt) {
2104 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2105 			" set on a registered nexus\n");
2106 		ret = TCM_INVALID_PARAMETER_LIST;
2107 		goto out;
2108 	}
2109 
2110 	/*
2111 	 * An existing ALL_TG_PT=1 registration being released
2112 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2113 	 */
2114 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2115 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2116 			" registration exists, but ALL_TG_PT=1 bit not"
2117 			" present in received PROUT\n");
2118 		ret = TCM_INVALID_CDB_FIELD;
2119 		goto out;
2120 	}
2121 
2122 	/*
2123 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2124 	 */
2125 	if (sa_res_key) {
2126 		/*
2127 		 * Increment PRgeneration counter for struct se_device"
2128 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2129 		 * READ_KEYS service action.
2130 		 */
2131 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2132 		pr_reg->pr_res_key = sa_res_key;
2133 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2134 			 " Key for %s to: 0x%016Lx PRgeneration:"
2135 			 " 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2136 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2137 			 pr_reg->pr_reg_nacl->initiatorname,
2138 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2139 
2140 	} else {
2141 		/*
2142 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2143 		 */
2144 		type = pr_reg->pr_res_type;
2145 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2146 							      pr_reg);
2147 		if (pr_holder < 0) {
2148 			ret = TCM_RESERVATION_CONFLICT;
2149 			goto out;
2150 		}
2151 
2152 		spin_lock(&pr_tmpl->registration_lock);
2153 		/*
2154 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2155 		 * and matching pr_res_key.
2156 		 */
2157 		if (pr_reg->pr_reg_all_tg_pt) {
2158 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2159 					&pr_tmpl->registration_list,
2160 					pr_reg_list) {
2161 
2162 				if (!pr_reg_p->pr_reg_all_tg_pt)
2163 					continue;
2164 				if (pr_reg_p->pr_res_key != res_key)
2165 					continue;
2166 				if (pr_reg == pr_reg_p)
2167 					continue;
2168 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2169 					   pr_reg_p->pr_reg_nacl->initiatorname))
2170 					continue;
2171 
2172 				__core_scsi3_free_registration(dev,
2173 						pr_reg_p, NULL, 0);
2174 			}
2175 		}
2176 
2177 		/*
2178 		 * Release the calling I_T Nexus registration now..
2179 		 */
2180 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2181 		pr_reg = NULL;
2182 
2183 		/*
2184 		 * From spc4r17, section 5.7.11.3 Unregistering
2185 		 *
2186 		 * If the persistent reservation is a registrants only
2187 		 * type, the device server shall establish a unit
2188 		 * attention condition for the initiator port associated
2189 		 * with every registered I_T nexus except for the I_T
2190 		 * nexus on which the PERSISTENT RESERVE OUT command was
2191 		 * received, with the additional sense code set to
2192 		 * RESERVATIONS RELEASED.
2193 		 */
2194 		if (pr_holder &&
2195 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2196 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2197 			list_for_each_entry(pr_reg_p,
2198 					&pr_tmpl->registration_list,
2199 					pr_reg_list) {
2200 
2201 				core_scsi3_ua_allocate(
2202 					pr_reg_p->pr_reg_nacl,
2203 					pr_reg_p->pr_res_mapped_lun,
2204 					0x2A,
2205 					ASCQ_2AH_RESERVATIONS_RELEASED);
2206 			}
2207 		}
2208 
2209 		spin_unlock(&pr_tmpl->registration_lock);
2210 	}
2211 
2212 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2213 
2214 out:
2215 	if (pr_reg)
2216 		core_scsi3_put_pr_reg(pr_reg);
2217 	return ret;
2218 }
2219 
2220 unsigned char *core_scsi3_pr_dump_type(int type)
2221 {
2222 	switch (type) {
2223 	case PR_TYPE_WRITE_EXCLUSIVE:
2224 		return "Write Exclusive Access";
2225 	case PR_TYPE_EXCLUSIVE_ACCESS:
2226 		return "Exclusive Access";
2227 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2228 		return "Write Exclusive Access, Registrants Only";
2229 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2230 		return "Exclusive Access, Registrants Only";
2231 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2232 		return "Write Exclusive Access, All Registrants";
2233 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2234 		return "Exclusive Access, All Registrants";
2235 	default:
2236 		break;
2237 	}
2238 
2239 	return "Unknown SPC-3 PR Type";
2240 }
2241 
2242 static sense_reason_t
2243 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2244 {
2245 	struct se_device *dev = cmd->se_dev;
2246 	struct se_session *se_sess = cmd->se_sess;
2247 	struct se_lun *se_lun = cmd->se_lun;
2248 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2249 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2250 	char i_buf[PR_REG_ISID_ID_LEN];
2251 	sense_reason_t ret;
2252 
2253 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2254 
2255 	if (!se_sess || !se_lun) {
2256 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2257 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2258 	}
2259 	/*
2260 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2261 	 */
2262 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2263 				se_sess);
2264 	if (!pr_reg) {
2265 		pr_err("SPC-3 PR: Unable to locate"
2266 			" PR_REGISTERED *pr_reg for RESERVE\n");
2267 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2268 	}
2269 	/*
2270 	 * From spc4r17 Section 5.7.9: Reserving:
2271 	 *
2272 	 * An application client creates a persistent reservation by issuing
2273 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2274 	 * a registered I_T nexus with the following parameters:
2275 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2276 	 * 	 registered with the logical unit for the I_T nexus; and
2277 	 */
2278 	if (res_key != pr_reg->pr_res_key) {
2279 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2280 			" does not match existing SA REGISTER res_key:"
2281 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2282 		ret = TCM_RESERVATION_CONFLICT;
2283 		goto out_put_pr_reg;
2284 	}
2285 	/*
2286 	 * From spc4r17 Section 5.7.9: Reserving:
2287 	 *
2288 	 * From above:
2289 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2290 	 *     being created.
2291 	 *
2292 	 * Only one persistent reservation is allowed at a time per logical unit
2293 	 * and that persistent reservation has a scope of LU_SCOPE.
2294 	 */
2295 	if (scope != PR_SCOPE_LU_SCOPE) {
2296 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2297 		ret = TCM_INVALID_PARAMETER_LIST;
2298 		goto out_put_pr_reg;
2299 	}
2300 	/*
2301 	 * See if we have an existing PR reservation holder pointer at
2302 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2303 	 * *pr_res_holder.
2304 	 */
2305 	spin_lock(&dev->dev_reservation_lock);
2306 	pr_res_holder = dev->dev_pr_res_holder;
2307 	if (pr_res_holder) {
2308 		/*
2309 		 * From spc4r17 Section 5.7.9: Reserving:
2310 		 *
2311 		 * If the device server receives a PERSISTENT RESERVE OUT
2312 		 * command from an I_T nexus other than a persistent reservation
2313 		 * holder (see 5.7.10) that attempts to create a persistent
2314 		 * reservation when a persistent reservation already exists for
2315 		 * the logical unit, then the command shall be completed with
2316 		 * RESERVATION CONFLICT status.
2317 		 */
2318 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2319 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2320 			pr_err("SPC-3 PR: Attempted RESERVE from"
2321 				" [%s]: %s while reservation already held by"
2322 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2323 				cmd->se_tfo->get_fabric_name(),
2324 				se_sess->se_node_acl->initiatorname,
2325 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2326 				pr_res_holder->pr_reg_nacl->initiatorname);
2327 
2328 			spin_unlock(&dev->dev_reservation_lock);
2329 			ret = TCM_RESERVATION_CONFLICT;
2330 			goto out_put_pr_reg;
2331 		}
2332 		/*
2333 		 * From spc4r17 Section 5.7.9: Reserving:
2334 		 *
2335 		 * If a persistent reservation holder attempts to modify the
2336 		 * type or scope of an existing persistent reservation, the
2337 		 * command shall be completed with RESERVATION CONFLICT status.
2338 		 */
2339 		if ((pr_res_holder->pr_res_type != type) ||
2340 		    (pr_res_holder->pr_res_scope != scope)) {
2341 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2342 			pr_err("SPC-3 PR: Attempted RESERVE from"
2343 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2344 				" while reservation already held by [%s]: %s,"
2345 				" returning RESERVATION_CONFLICT\n",
2346 				cmd->se_tfo->get_fabric_name(),
2347 				se_sess->se_node_acl->initiatorname,
2348 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2349 				pr_res_holder->pr_reg_nacl->initiatorname);
2350 
2351 			spin_unlock(&dev->dev_reservation_lock);
2352 			ret = TCM_RESERVATION_CONFLICT;
2353 			goto out_put_pr_reg;
2354 		}
2355 		/*
2356 		 * From spc4r17 Section 5.7.9: Reserving:
2357 		 *
2358 		 * If the device server receives a PERSISTENT RESERVE OUT
2359 		 * command with RESERVE service action where the TYPE field and
2360 		 * the SCOPE field contain the same values as the existing type
2361 		 * and scope from a persistent reservation holder, it shall not
2362 		 * make any change to the existing persistent reservation and
2363 		 * shall completethe command with GOOD status.
2364 		 */
2365 		spin_unlock(&dev->dev_reservation_lock);
2366 		ret = 0;
2367 		goto out_put_pr_reg;
2368 	}
2369 	/*
2370 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2371 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2372 	 */
2373 	pr_reg->pr_res_scope = scope;
2374 	pr_reg->pr_res_type = type;
2375 	pr_reg->pr_res_holder = 1;
2376 	dev->dev_pr_res_holder = pr_reg;
2377 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2378 
2379 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2380 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2381 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2382 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2383 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2384 			cmd->se_tfo->get_fabric_name(),
2385 			se_sess->se_node_acl->initiatorname,
2386 			i_buf);
2387 	spin_unlock(&dev->dev_reservation_lock);
2388 
2389 	if (pr_tmpl->pr_aptpl_active)
2390 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2391 
2392 	ret = 0;
2393 out_put_pr_reg:
2394 	core_scsi3_put_pr_reg(pr_reg);
2395 	return ret;
2396 }
2397 
2398 static sense_reason_t
2399 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2400 		u64 res_key)
2401 {
2402 	switch (type) {
2403 	case PR_TYPE_WRITE_EXCLUSIVE:
2404 	case PR_TYPE_EXCLUSIVE_ACCESS:
2405 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2406 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2407 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2408 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2409 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2410 	default:
2411 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2412 			" 0x%02x\n", type);
2413 		return TCM_INVALID_CDB_FIELD;
2414 	}
2415 }
2416 
2417 /*
2418  * Called with struct se_device->dev_reservation_lock held.
2419  */
2420 static void __core_scsi3_complete_pro_release(
2421 	struct se_device *dev,
2422 	struct se_node_acl *se_nacl,
2423 	struct t10_pr_registration *pr_reg,
2424 	int explicit,
2425 	int unreg)
2426 {
2427 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2428 	char i_buf[PR_REG_ISID_ID_LEN];
2429 	int pr_res_type = 0, pr_res_scope = 0;
2430 
2431 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2432 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2433 	/*
2434 	 * Go ahead and release the current PR reservation holder.
2435 	 * If an All Registrants reservation is currently active and
2436 	 * a unregister operation is requested, replace the current
2437 	 * dev_pr_res_holder with another active registration.
2438 	 */
2439 	if (dev->dev_pr_res_holder) {
2440 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2441 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2442 		dev->dev_pr_res_holder->pr_res_type = 0;
2443 		dev->dev_pr_res_holder->pr_res_scope = 0;
2444 		dev->dev_pr_res_holder->pr_res_holder = 0;
2445 		dev->dev_pr_res_holder = NULL;
2446 	}
2447 	if (!unreg)
2448 		goto out;
2449 
2450 	spin_lock(&dev->t10_pr.registration_lock);
2451 	list_del_init(&pr_reg->pr_reg_list);
2452 	/*
2453 	 * If the I_T nexus is a reservation holder, the persistent reservation
2454 	 * is of an all registrants type, and the I_T nexus is the last remaining
2455 	 * registered I_T nexus, then the device server shall also release the
2456 	 * persistent reservation.
2457 	 */
2458 	if (!list_empty(&dev->t10_pr.registration_list) &&
2459 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2460 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2461 		dev->dev_pr_res_holder =
2462 			list_entry(dev->t10_pr.registration_list.next,
2463 				   struct t10_pr_registration, pr_reg_list);
2464 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2465 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2466 		dev->dev_pr_res_holder->pr_res_holder = 1;
2467 	}
2468 	spin_unlock(&dev->t10_pr.registration_lock);
2469 out:
2470 	if (!dev->dev_pr_res_holder) {
2471 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2472 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2473 			tfo->get_fabric_name(), (explicit) ? "explicit" :
2474 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2475 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2476 	}
2477 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2478 		tfo->get_fabric_name(), se_nacl->initiatorname,
2479 		i_buf);
2480 	/*
2481 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2482 	 */
2483 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2484 }
2485 
2486 static sense_reason_t
2487 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2488 		u64 res_key)
2489 {
2490 	struct se_device *dev = cmd->se_dev;
2491 	struct se_session *se_sess = cmd->se_sess;
2492 	struct se_lun *se_lun = cmd->se_lun;
2493 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2494 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2495 	sense_reason_t ret = 0;
2496 
2497 	if (!se_sess || !se_lun) {
2498 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2499 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2500 	}
2501 	/*
2502 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2503 	 */
2504 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2505 	if (!pr_reg) {
2506 		pr_err("SPC-3 PR: Unable to locate"
2507 			" PR_REGISTERED *pr_reg for RELEASE\n");
2508 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2509 	}
2510 	/*
2511 	 * From spc4r17 Section 5.7.11.2 Releasing:
2512 	 *
2513 	 * If there is no persistent reservation or in response to a persistent
2514 	 * reservation release request from a registered I_T nexus that is not a
2515 	 * persistent reservation holder (see 5.7.10), the device server shall
2516 	 * do the following:
2517 	 *
2518 	 *     a) Not release the persistent reservation, if any;
2519 	 *     b) Not remove any registrations; and
2520 	 *     c) Complete the command with GOOD status.
2521 	 */
2522 	spin_lock(&dev->dev_reservation_lock);
2523 	pr_res_holder = dev->dev_pr_res_holder;
2524 	if (!pr_res_holder) {
2525 		/*
2526 		 * No persistent reservation, return GOOD status.
2527 		 */
2528 		spin_unlock(&dev->dev_reservation_lock);
2529 		goto out_put_pr_reg;
2530 	}
2531 
2532 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2533 		/*
2534 		 * Release request from a registered I_T nexus that is not a
2535 		 * persistent reservation holder. return GOOD status.
2536 		 */
2537 		spin_unlock(&dev->dev_reservation_lock);
2538 		goto out_put_pr_reg;
2539 	}
2540 
2541 	/*
2542 	 * From spc4r17 Section 5.7.11.2 Releasing:
2543 	 *
2544 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2545 	 * release a persistent reservation.
2546 	 *
2547 	 * An application client releases the persistent reservation by issuing
2548 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2549 	 * an I_T nexus that is a persistent reservation holder with the
2550 	 * following parameters:
2551 	 *
2552 	 *     a) RESERVATION KEY field set to the value of the reservation key
2553 	 *	  that is registered with the logical unit for the I_T nexus;
2554 	 */
2555 	if (res_key != pr_reg->pr_res_key) {
2556 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2557 			" does not match existing SA REGISTER res_key:"
2558 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2559 		spin_unlock(&dev->dev_reservation_lock);
2560 		ret = TCM_RESERVATION_CONFLICT;
2561 		goto out_put_pr_reg;
2562 	}
2563 	/*
2564 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2565 	 *
2566 	 * b) TYPE field and SCOPE field set to match the persistent
2567 	 *    reservation being released.
2568 	 */
2569 	if ((pr_res_holder->pr_res_type != type) ||
2570 	    (pr_res_holder->pr_res_scope != scope)) {
2571 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2572 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2573 			" reservation from [%s]: %s with different TYPE "
2574 			"and/or SCOPE  while reservation already held by"
2575 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2576 			cmd->se_tfo->get_fabric_name(),
2577 			se_sess->se_node_acl->initiatorname,
2578 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2579 			pr_res_holder->pr_reg_nacl->initiatorname);
2580 
2581 		spin_unlock(&dev->dev_reservation_lock);
2582 		ret = TCM_RESERVATION_CONFLICT;
2583 		goto out_put_pr_reg;
2584 	}
2585 	/*
2586 	 * In response to a persistent reservation release request from the
2587 	 * persistent reservation holder the device server shall perform a
2588 	 * release by doing the following as an uninterrupted series of actions:
2589 	 * a) Release the persistent reservation;
2590 	 * b) Not remove any registration(s);
2591 	 * c) If the released persistent reservation is a registrants only type
2592 	 * or all registrants type persistent reservation,
2593 	 *    the device server shall establish a unit attention condition for
2594 	 *    the initiator port associated with every regis-
2595 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2596 	 *    RESERVE OUT command with RELEASE service action was received,
2597 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2598 	 * d) If the persistent reservation is of any other type, the device
2599 	 *    server shall not establish a unit attention condition.
2600 	 */
2601 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2602 					  pr_reg, 1, 0);
2603 
2604 	spin_unlock(&dev->dev_reservation_lock);
2605 
2606 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2607 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2608 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2609 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2610 		/*
2611 		 * If no UNIT ATTENTION conditions will be established for
2612 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2613 		 * go ahead and check for APTPL=1 update+write below
2614 		 */
2615 		goto write_aptpl;
2616 	}
2617 
2618 	spin_lock(&pr_tmpl->registration_lock);
2619 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2620 			pr_reg_list) {
2621 		/*
2622 		 * Do not establish a UNIT ATTENTION condition
2623 		 * for the calling I_T Nexus
2624 		 */
2625 		if (pr_reg_p == pr_reg)
2626 			continue;
2627 
2628 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2629 				pr_reg_p->pr_res_mapped_lun,
2630 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2631 	}
2632 	spin_unlock(&pr_tmpl->registration_lock);
2633 
2634 write_aptpl:
2635 	if (pr_tmpl->pr_aptpl_active)
2636 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2637 
2638 out_put_pr_reg:
2639 	core_scsi3_put_pr_reg(pr_reg);
2640 	return ret;
2641 }
2642 
2643 static sense_reason_t
2644 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2645 {
2646 	struct se_device *dev = cmd->se_dev;
2647 	struct se_node_acl *pr_reg_nacl;
2648 	struct se_session *se_sess = cmd->se_sess;
2649 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2650 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2651 	u32 pr_res_mapped_lun = 0;
2652 	int calling_it_nexus = 0;
2653 	/*
2654 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2655 	 */
2656 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2657 			se_sess->se_node_acl, se_sess);
2658 	if (!pr_reg_n) {
2659 		pr_err("SPC-3 PR: Unable to locate"
2660 			" PR_REGISTERED *pr_reg for CLEAR\n");
2661 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2662 	}
2663 	/*
2664 	 * From spc4r17 section 5.7.11.6, Clearing:
2665 	 *
2666 	 * Any application client may release the persistent reservation and
2667 	 * remove all registrations from a device server by issuing a
2668 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2669 	 * registered I_T nexus with the following parameter:
2670 	 *
2671 	 *	a) RESERVATION KEY field set to the value of the reservation key
2672 	 * 	   that is registered with the logical unit for the I_T nexus.
2673 	 */
2674 	if (res_key != pr_reg_n->pr_res_key) {
2675 		pr_err("SPC-3 PR REGISTER: Received"
2676 			" res_key: 0x%016Lx does not match"
2677 			" existing SA REGISTER res_key:"
2678 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2679 		core_scsi3_put_pr_reg(pr_reg_n);
2680 		return TCM_RESERVATION_CONFLICT;
2681 	}
2682 	/*
2683 	 * a) Release the persistent reservation, if any;
2684 	 */
2685 	spin_lock(&dev->dev_reservation_lock);
2686 	pr_res_holder = dev->dev_pr_res_holder;
2687 	if (pr_res_holder) {
2688 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2689 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2690 						  pr_res_holder, 0, 0);
2691 	}
2692 	spin_unlock(&dev->dev_reservation_lock);
2693 	/*
2694 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2695 	 */
2696 	spin_lock(&pr_tmpl->registration_lock);
2697 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2698 			&pr_tmpl->registration_list, pr_reg_list) {
2699 
2700 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2701 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2702 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2703 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2704 					calling_it_nexus);
2705 		/*
2706 		 * e) Establish a unit attention condition for the initiator
2707 		 *    port associated with every registered I_T nexus other
2708 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2709 		 *    command with CLEAR service action was received, with the
2710 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2711 		 */
2712 		if (!calling_it_nexus)
2713 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2714 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2715 	}
2716 	spin_unlock(&pr_tmpl->registration_lock);
2717 
2718 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2719 		cmd->se_tfo->get_fabric_name());
2720 
2721 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2722 
2723 	core_scsi3_pr_generation(dev);
2724 	return 0;
2725 }
2726 
2727 /*
2728  * Called with struct se_device->dev_reservation_lock held.
2729  */
2730 static void __core_scsi3_complete_pro_preempt(
2731 	struct se_device *dev,
2732 	struct t10_pr_registration *pr_reg,
2733 	struct list_head *preempt_and_abort_list,
2734 	int type,
2735 	int scope,
2736 	enum preempt_type preempt_type)
2737 {
2738 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2739 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2740 	char i_buf[PR_REG_ISID_ID_LEN];
2741 
2742 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2743 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2744 	/*
2745 	 * Do an implicit RELEASE of the existing reservation.
2746 	 */
2747 	if (dev->dev_pr_res_holder)
2748 		__core_scsi3_complete_pro_release(dev, nacl,
2749 						  dev->dev_pr_res_holder, 0, 0);
2750 
2751 	dev->dev_pr_res_holder = pr_reg;
2752 	pr_reg->pr_res_holder = 1;
2753 	pr_reg->pr_res_type = type;
2754 	pr_reg->pr_res_scope = scope;
2755 
2756 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2757 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2758 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2759 		core_scsi3_pr_dump_type(type),
2760 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2761 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2762 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2763 		nacl->initiatorname, i_buf);
2764 	/*
2765 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2766 	 * struct t10_pr_registration to the list that will be compared
2767 	 * against received CDBs..
2768 	 */
2769 	if (preempt_and_abort_list)
2770 		list_add_tail(&pr_reg->pr_reg_abort_list,
2771 				preempt_and_abort_list);
2772 }
2773 
2774 static void core_scsi3_release_preempt_and_abort(
2775 	struct list_head *preempt_and_abort_list,
2776 	struct t10_pr_registration *pr_reg_holder)
2777 {
2778 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2779 
2780 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2781 				pr_reg_abort_list) {
2782 
2783 		list_del(&pr_reg->pr_reg_abort_list);
2784 		if (pr_reg_holder == pr_reg)
2785 			continue;
2786 		if (pr_reg->pr_res_holder) {
2787 			pr_warn("pr_reg->pr_res_holder still set\n");
2788 			continue;
2789 		}
2790 
2791 		pr_reg->pr_reg_deve = NULL;
2792 		pr_reg->pr_reg_nacl = NULL;
2793 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2794 	}
2795 }
2796 
2797 static sense_reason_t
2798 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2799 		u64 sa_res_key, enum preempt_type preempt_type)
2800 {
2801 	struct se_device *dev = cmd->se_dev;
2802 	struct se_node_acl *pr_reg_nacl;
2803 	struct se_session *se_sess = cmd->se_sess;
2804 	LIST_HEAD(preempt_and_abort_list);
2805 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2806 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2807 	u32 pr_res_mapped_lun = 0;
2808 	int all_reg = 0, calling_it_nexus = 0;
2809 	bool sa_res_key_unmatched = sa_res_key != 0;
2810 	int prh_type = 0, prh_scope = 0;
2811 
2812 	if (!se_sess)
2813 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2814 
2815 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2816 				se_sess);
2817 	if (!pr_reg_n) {
2818 		pr_err("SPC-3 PR: Unable to locate"
2819 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2820 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2821 		return TCM_RESERVATION_CONFLICT;
2822 	}
2823 	if (pr_reg_n->pr_res_key != res_key) {
2824 		core_scsi3_put_pr_reg(pr_reg_n);
2825 		return TCM_RESERVATION_CONFLICT;
2826 	}
2827 	if (scope != PR_SCOPE_LU_SCOPE) {
2828 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2829 		core_scsi3_put_pr_reg(pr_reg_n);
2830 		return TCM_INVALID_PARAMETER_LIST;
2831 	}
2832 
2833 	spin_lock(&dev->dev_reservation_lock);
2834 	pr_res_holder = dev->dev_pr_res_holder;
2835 	if (pr_res_holder &&
2836 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2837 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2838 		all_reg = 1;
2839 
2840 	if (!all_reg && !sa_res_key) {
2841 		spin_unlock(&dev->dev_reservation_lock);
2842 		core_scsi3_put_pr_reg(pr_reg_n);
2843 		return TCM_INVALID_PARAMETER_LIST;
2844 	}
2845 	/*
2846 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2847 	 *
2848 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2849 	 * persistent reservation holder or there is no persistent reservation
2850 	 * holder (i.e., there is no persistent reservation), then the device
2851 	 * server shall perform a preempt by doing the following in an
2852 	 * uninterrupted series of actions. (See below..)
2853 	 */
2854 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2855 		/*
2856 		 * No existing or SA Reservation Key matching reservations..
2857 		 *
2858 		 * PROUT SA PREEMPT with All Registrant type reservations are
2859 		 * allowed to be processed without a matching SA Reservation Key
2860 		 */
2861 		spin_lock(&pr_tmpl->registration_lock);
2862 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2863 				&pr_tmpl->registration_list, pr_reg_list) {
2864 			/*
2865 			 * Removing of registrations in non all registrants
2866 			 * type reservations without a matching SA reservation
2867 			 * key.
2868 			 *
2869 			 * a) Remove the registrations for all I_T nexuses
2870 			 *    specified by the SERVICE ACTION RESERVATION KEY
2871 			 *    field;
2872 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2873 			 * c) Process tasks as defined in 5.7.1; and
2874 			 * d) Establish a unit attention condition for the
2875 			 *    initiator port associated with every I_T nexus
2876 			 *    that lost its registration other than the I_T
2877 			 *    nexus on which the PERSISTENT RESERVE OUT command
2878 			 *    was received, with the additional sense code set
2879 			 *    to REGISTRATIONS PREEMPTED.
2880 			 */
2881 			if (!all_reg) {
2882 				if (pr_reg->pr_res_key != sa_res_key)
2883 					continue;
2884 				sa_res_key_unmatched = false;
2885 
2886 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2887 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2888 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2889 				__core_scsi3_free_registration(dev, pr_reg,
2890 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2891 						NULL, calling_it_nexus);
2892 			} else {
2893 				/*
2894 				 * Case for any existing all registrants type
2895 				 * reservation, follow logic in spc4r17 section
2896 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2897 				 *
2898 				 * For a ZERO SA Reservation key, release
2899 				 * all other registrations and do an implicit
2900 				 * release of active persistent reservation.
2901 				 *
2902 				 * For a non-ZERO SA Reservation key, only
2903 				 * release the matching reservation key from
2904 				 * registrations.
2905 				 */
2906 				if ((sa_res_key) &&
2907 				     (pr_reg->pr_res_key != sa_res_key))
2908 					continue;
2909 				sa_res_key_unmatched = false;
2910 
2911 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2912 				if (calling_it_nexus)
2913 					continue;
2914 
2915 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2916 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2917 				__core_scsi3_free_registration(dev, pr_reg,
2918 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2919 						NULL, 0);
2920 			}
2921 			if (!calling_it_nexus)
2922 				core_scsi3_ua_allocate(pr_reg_nacl,
2923 					pr_res_mapped_lun, 0x2A,
2924 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2925 		}
2926 		spin_unlock(&pr_tmpl->registration_lock);
2927 		/*
2928 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2929 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2930 		 * RESERVATION KEY field to a value that does not match any
2931 		 * registered reservation key, then the device server shall
2932 		 * complete the command with RESERVATION CONFLICT status.
2933 		 */
2934 		if (sa_res_key_unmatched) {
2935 			spin_unlock(&dev->dev_reservation_lock);
2936 			core_scsi3_put_pr_reg(pr_reg_n);
2937 			return TCM_RESERVATION_CONFLICT;
2938 		}
2939 		/*
2940 		 * For an existing all registrants type reservation
2941 		 * with a zero SA rservation key, preempt the existing
2942 		 * reservation with the new PR type and scope.
2943 		 */
2944 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2945 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2946 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2947 				type, scope, preempt_type);
2948 
2949 			if (preempt_type == PREEMPT_AND_ABORT)
2950 				core_scsi3_release_preempt_and_abort(
2951 					&preempt_and_abort_list, pr_reg_n);
2952 		}
2953 		spin_unlock(&dev->dev_reservation_lock);
2954 
2955 		if (pr_tmpl->pr_aptpl_active)
2956 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2957 
2958 		core_scsi3_put_pr_reg(pr_reg_n);
2959 		core_scsi3_pr_generation(cmd->se_dev);
2960 		return 0;
2961 	}
2962 	/*
2963 	 * The PREEMPTing SA reservation key matches that of the
2964 	 * existing persistent reservation, first, we check if
2965 	 * we are preempting our own reservation.
2966 	 * From spc4r17, section 5.7.11.4.3 Preempting
2967 	 * persistent reservations and registration handling
2968 	 *
2969 	 * If an all registrants persistent reservation is not
2970 	 * present, it is not an error for the persistent
2971 	 * reservation holder to preempt itself (i.e., a
2972 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
2973 	 * or a PREEMPT AND ABORT service action with the
2974 	 * SERVICE ACTION RESERVATION KEY value equal to the
2975 	 * persistent reservation holder's reservation key that
2976 	 * is received from the persistent reservation holder).
2977 	 * In that case, the device server shall establish the
2978 	 * new persistent reservation and maintain the
2979 	 * registration.
2980 	 */
2981 	prh_type = pr_res_holder->pr_res_type;
2982 	prh_scope = pr_res_holder->pr_res_scope;
2983 	/*
2984 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
2985 	 * persistent reservation holder (see 5.7.10), the device
2986 	 * server shall perform a preempt by doing the following as
2987 	 * an uninterrupted series of actions:
2988 	 *
2989 	 * a) Release the persistent reservation for the holder
2990 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
2991 	 */
2992 	if (pr_reg_n != pr_res_holder)
2993 		__core_scsi3_complete_pro_release(dev,
2994 						  pr_res_holder->pr_reg_nacl,
2995 						  dev->dev_pr_res_holder, 0, 0);
2996 	/*
2997 	 * b) Remove the registrations for all I_T nexuses identified
2998 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
2999 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3000 	 *    OUT command. If an all registrants persistent reservation
3001 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3002 	 *    is set to zero, then all registrations shall be removed
3003 	 *    except for that of the I_T nexus that is being used for
3004 	 *    the PERSISTENT RESERVE OUT command;
3005 	 */
3006 	spin_lock(&pr_tmpl->registration_lock);
3007 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3008 			&pr_tmpl->registration_list, pr_reg_list) {
3009 
3010 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3011 		if (calling_it_nexus)
3012 			continue;
3013 
3014 		if (pr_reg->pr_res_key != sa_res_key)
3015 			continue;
3016 
3017 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3018 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3019 		__core_scsi3_free_registration(dev, pr_reg,
3020 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3021 				calling_it_nexus);
3022 		/*
3023 		 * e) Establish a unit attention condition for the initiator
3024 		 *    port associated with every I_T nexus that lost its
3025 		 *    persistent reservation and/or registration, with the
3026 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3027 		 */
3028 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3029 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3030 	}
3031 	spin_unlock(&pr_tmpl->registration_lock);
3032 	/*
3033 	 * c) Establish a persistent reservation for the preempting
3034 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3035 	 */
3036 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3037 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3038 			type, scope, preempt_type);
3039 	/*
3040 	 * d) Process tasks as defined in 5.7.1;
3041 	 * e) See above..
3042 	 * f) If the type or scope has changed, then for every I_T nexus
3043 	 *    whose reservation key was not removed, except for the I_T
3044 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3045 	 *    received, the device server shall establish a unit
3046 	 *    attention condition for the initiator port associated with
3047 	 *    that I_T nexus, with the additional sense code set to
3048 	 *    RESERVATIONS RELEASED. If the type or scope have not
3049 	 *    changed, then no unit attention condition(s) shall be
3050 	 *    established for this reason.
3051 	 */
3052 	if ((prh_type != type) || (prh_scope != scope)) {
3053 		spin_lock(&pr_tmpl->registration_lock);
3054 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3055 				&pr_tmpl->registration_list, pr_reg_list) {
3056 
3057 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3058 			if (calling_it_nexus)
3059 				continue;
3060 
3061 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
3062 					pr_reg->pr_res_mapped_lun, 0x2A,
3063 					ASCQ_2AH_RESERVATIONS_RELEASED);
3064 		}
3065 		spin_unlock(&pr_tmpl->registration_lock);
3066 	}
3067 	spin_unlock(&dev->dev_reservation_lock);
3068 	/*
3069 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3070 	 * All received CDBs for the matching existing reservation and
3071 	 * registrations undergo ABORT_TASK logic.
3072 	 *
3073 	 * From there, core_scsi3_release_preempt_and_abort() will
3074 	 * release every registration in the list (which have already
3075 	 * been removed from the primary pr_reg list), except the
3076 	 * new persistent reservation holder, the calling Initiator Port.
3077 	 */
3078 	if (preempt_type == PREEMPT_AND_ABORT) {
3079 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3080 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3081 						pr_reg_n);
3082 	}
3083 
3084 	if (pr_tmpl->pr_aptpl_active)
3085 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3086 
3087 	core_scsi3_put_pr_reg(pr_reg_n);
3088 	core_scsi3_pr_generation(cmd->se_dev);
3089 	return 0;
3090 }
3091 
3092 static sense_reason_t
3093 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3094 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3095 {
3096 	switch (type) {
3097 	case PR_TYPE_WRITE_EXCLUSIVE:
3098 	case PR_TYPE_EXCLUSIVE_ACCESS:
3099 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3100 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3101 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3102 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3103 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3104 					      sa_res_key, preempt_type);
3105 	default:
3106 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3107 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3108 		return TCM_INVALID_CDB_FIELD;
3109 	}
3110 }
3111 
3112 
3113 static sense_reason_t
3114 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3115 		u64 sa_res_key, int aptpl, int unreg)
3116 {
3117 	struct se_session *se_sess = cmd->se_sess;
3118 	struct se_device *dev = cmd->se_dev;
3119 	struct se_dev_entry *dest_se_deve = NULL;
3120 	struct se_lun *se_lun = cmd->se_lun;
3121 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3122 	struct se_port *se_port;
3123 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3124 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3125 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3126 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3127 	unsigned char *buf;
3128 	unsigned char *initiator_str;
3129 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
3130 	u32 tid_len, tmp_tid_len;
3131 	int new_reg = 0, type, scope, matching_iname;
3132 	sense_reason_t ret;
3133 	unsigned short rtpi;
3134 	unsigned char proto_ident;
3135 
3136 	if (!se_sess || !se_lun) {
3137 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3138 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3139 	}
3140 
3141 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3142 	se_tpg = se_sess->se_tpg;
3143 	tf_ops = se_tpg->se_tpg_tfo;
3144 	/*
3145 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3146 	 *	Register behaviors for a REGISTER AND MOVE service action
3147 	 *
3148 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3149 	 */
3150 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3151 				se_sess);
3152 	if (!pr_reg) {
3153 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3154 			" *pr_reg for REGISTER_AND_MOVE\n");
3155 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3156 	}
3157 	/*
3158 	 * The provided reservation key much match the existing reservation key
3159 	 * provided during this initiator's I_T nexus registration.
3160 	 */
3161 	if (res_key != pr_reg->pr_res_key) {
3162 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3163 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3164 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3165 		ret = TCM_RESERVATION_CONFLICT;
3166 		goto out_put_pr_reg;
3167 	}
3168 	/*
3169 	 * The service active reservation key needs to be non zero
3170 	 */
3171 	if (!sa_res_key) {
3172 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3173 			" sa_res_key\n");
3174 		ret = TCM_INVALID_PARAMETER_LIST;
3175 		goto out_put_pr_reg;
3176 	}
3177 
3178 	/*
3179 	 * Determine the Relative Target Port Identifier where the reservation
3180 	 * will be moved to for the TransportID containing SCSI initiator WWN
3181 	 * information.
3182 	 */
3183 	buf = transport_kmap_data_sg(cmd);
3184 	if (!buf) {
3185 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3186 		goto out_put_pr_reg;
3187 	}
3188 
3189 	rtpi = (buf[18] & 0xff) << 8;
3190 	rtpi |= buf[19] & 0xff;
3191 	tid_len = (buf[20] & 0xff) << 24;
3192 	tid_len |= (buf[21] & 0xff) << 16;
3193 	tid_len |= (buf[22] & 0xff) << 8;
3194 	tid_len |= buf[23] & 0xff;
3195 	transport_kunmap_data_sg(cmd);
3196 	buf = NULL;
3197 
3198 	if ((tid_len + 24) != cmd->data_length) {
3199 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3200 			" does not equal CDB data_length: %u\n", tid_len,
3201 			cmd->data_length);
3202 		ret = TCM_INVALID_PARAMETER_LIST;
3203 		goto out_put_pr_reg;
3204 	}
3205 
3206 	spin_lock(&dev->se_port_lock);
3207 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3208 		if (se_port->sep_rtpi != rtpi)
3209 			continue;
3210 		dest_se_tpg = se_port->sep_tpg;
3211 		if (!dest_se_tpg)
3212 			continue;
3213 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3214 		if (!dest_tf_ops)
3215 			continue;
3216 
3217 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3218 		spin_unlock(&dev->se_port_lock);
3219 
3220 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3221 			pr_err("core_scsi3_tpg_depend_item() failed"
3222 				" for dest_se_tpg\n");
3223 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3224 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3225 			goto out_put_pr_reg;
3226 		}
3227 
3228 		spin_lock(&dev->se_port_lock);
3229 		break;
3230 	}
3231 	spin_unlock(&dev->se_port_lock);
3232 
3233 	if (!dest_se_tpg || !dest_tf_ops) {
3234 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3235 			" fabric ops from Relative Target Port Identifier:"
3236 			" %hu\n", rtpi);
3237 		ret = TCM_INVALID_PARAMETER_LIST;
3238 		goto out_put_pr_reg;
3239 	}
3240 
3241 	buf = transport_kmap_data_sg(cmd);
3242 	if (!buf) {
3243 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3244 		goto out_put_pr_reg;
3245 	}
3246 	proto_ident = (buf[24] & 0x0f);
3247 
3248 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3249 			" 0x%02x\n", proto_ident);
3250 
3251 	if (proto_ident != dest_tf_ops->get_fabric_proto_ident(dest_se_tpg)) {
3252 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3253 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3254 			" from fabric: %s\n", proto_ident,
3255 			dest_tf_ops->get_fabric_proto_ident(dest_se_tpg),
3256 			dest_tf_ops->get_fabric_name());
3257 		ret = TCM_INVALID_PARAMETER_LIST;
3258 		goto out;
3259 	}
3260 	if (dest_tf_ops->tpg_parse_pr_out_transport_id == NULL) {
3261 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Fabric does not"
3262 			" containg a valid tpg_parse_pr_out_transport_id"
3263 			" function pointer\n");
3264 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3265 		goto out;
3266 	}
3267 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(dest_se_tpg,
3268 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3269 	if (!initiator_str) {
3270 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3271 			" initiator_str from Transport ID\n");
3272 		ret = TCM_INVALID_PARAMETER_LIST;
3273 		goto out;
3274 	}
3275 
3276 	transport_kunmap_data_sg(cmd);
3277 	buf = NULL;
3278 
3279 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3280 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3281 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3282 		iport_ptr : "");
3283 	/*
3284 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3285 	 * action specifies a TransportID that is the same as the initiator port
3286 	 * of the I_T nexus for the command received, then the command shall
3287 	 * be terminated with CHECK CONDITION status, with the sense key set to
3288 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3289 	 * IN PARAMETER LIST.
3290 	 */
3291 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3292 	matching_iname = (!strcmp(initiator_str,
3293 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3294 	if (!matching_iname)
3295 		goto after_iport_check;
3296 
3297 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3298 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3299 			" matches: %s on received I_T Nexus\n", initiator_str,
3300 			pr_reg_nacl->initiatorname);
3301 		ret = TCM_INVALID_PARAMETER_LIST;
3302 		goto out;
3303 	}
3304 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3305 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3306 			" matches: %s %s on received I_T Nexus\n",
3307 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3308 			pr_reg->pr_reg_isid);
3309 		ret = TCM_INVALID_PARAMETER_LIST;
3310 		goto out;
3311 	}
3312 after_iport_check:
3313 	/*
3314 	 * Locate the destination struct se_node_acl from the received Transport ID
3315 	 */
3316 	spin_lock_irq(&dest_se_tpg->acl_node_lock);
3317 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3318 				initiator_str);
3319 	if (dest_node_acl)
3320 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3321 	spin_unlock_irq(&dest_se_tpg->acl_node_lock);
3322 
3323 	if (!dest_node_acl) {
3324 		pr_err("Unable to locate %s dest_node_acl for"
3325 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3326 			initiator_str);
3327 		ret = TCM_INVALID_PARAMETER_LIST;
3328 		goto out;
3329 	}
3330 
3331 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3332 		pr_err("core_scsi3_nodeacl_depend_item() for"
3333 			" dest_node_acl\n");
3334 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3335 		dest_node_acl = NULL;
3336 		ret = TCM_INVALID_PARAMETER_LIST;
3337 		goto out;
3338 	}
3339 
3340 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3341 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3342 		dest_node_acl->initiatorname);
3343 
3344 	/*
3345 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3346 	 * PORT IDENTIFIER.
3347 	 */
3348 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3349 	if (!dest_se_deve) {
3350 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3351 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3352 		ret = TCM_INVALID_PARAMETER_LIST;
3353 		goto out;
3354 	}
3355 
3356 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3357 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3358 		atomic_dec_mb(&dest_se_deve->pr_ref_count);
3359 		dest_se_deve = NULL;
3360 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3361 		goto out;
3362 	}
3363 
3364 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3365 		" ACL for dest_se_deve->mapped_lun: %u\n",
3366 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3367 		dest_se_deve->mapped_lun);
3368 
3369 	/*
3370 	 * A persistent reservation needs to already existing in order to
3371 	 * successfully complete the REGISTER_AND_MOVE service action..
3372 	 */
3373 	spin_lock(&dev->dev_reservation_lock);
3374 	pr_res_holder = dev->dev_pr_res_holder;
3375 	if (!pr_res_holder) {
3376 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3377 			" currently held\n");
3378 		spin_unlock(&dev->dev_reservation_lock);
3379 		ret = TCM_INVALID_CDB_FIELD;
3380 		goto out;
3381 	}
3382 	/*
3383 	 * The received on I_T Nexus must be the reservation holder.
3384 	 *
3385 	 * From spc4r17 section 5.7.8  Table 50 --
3386 	 * 	Register behaviors for a REGISTER AND MOVE service action
3387 	 */
3388 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3389 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3390 			" Nexus is not reservation holder\n");
3391 		spin_unlock(&dev->dev_reservation_lock);
3392 		ret = TCM_RESERVATION_CONFLICT;
3393 		goto out;
3394 	}
3395 	/*
3396 	 * From spc4r17 section 5.7.8: registering and moving reservation
3397 	 *
3398 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3399 	 * action is received and the established persistent reservation is a
3400 	 * Write Exclusive - All Registrants type or Exclusive Access -
3401 	 * All Registrants type reservation, then the command shall be completed
3402 	 * with RESERVATION CONFLICT status.
3403 	 */
3404 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3405 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3406 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3407 			" reservation for type: %s\n",
3408 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3409 		spin_unlock(&dev->dev_reservation_lock);
3410 		ret = TCM_RESERVATION_CONFLICT;
3411 		goto out;
3412 	}
3413 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3414 	/*
3415 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3416 	 */
3417 	type = pr_res_holder->pr_res_type;
3418 	scope = pr_res_holder->pr_res_type;
3419 	/*
3420 	 * c) Associate the reservation key specified in the SERVICE ACTION
3421 	 *    RESERVATION KEY field with the I_T nexus specified as the
3422 	 *    destination of the register and move, where:
3423 	 *    A) The I_T nexus is specified by the TransportID and the
3424 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3425 	 *    B) Regardless of the TransportID format used, the association for
3426 	 *       the initiator port is based on either the initiator port name
3427 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3428 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3429 	 *       transport protocols where port names are not required;
3430 	 * d) Register the reservation key specified in the SERVICE ACTION
3431 	 *    RESERVATION KEY field;
3432 	 * e) Retain the reservation key specified in the SERVICE ACTION
3433 	 *    RESERVATION KEY field and associated information;
3434 	 *
3435 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3436 	 * register an I_T nexus that is already registered with the same
3437 	 * reservation key or a different reservation key.
3438 	 */
3439 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3440 					iport_ptr);
3441 	if (!dest_pr_reg) {
3442 		if (core_scsi3_alloc_registration(cmd->se_dev,
3443 				dest_node_acl, dest_se_deve, iport_ptr,
3444 				sa_res_key, 0, aptpl, 2, 1)) {
3445 			spin_unlock(&dev->dev_reservation_lock);
3446 			ret = TCM_INVALID_PARAMETER_LIST;
3447 			goto out;
3448 		}
3449 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3450 						iport_ptr);
3451 		new_reg = 1;
3452 	}
3453 	/*
3454 	 * f) Release the persistent reservation for the persistent reservation
3455 	 *    holder (i.e., the I_T nexus on which the
3456 	 */
3457 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3458 					  dev->dev_pr_res_holder, 0, 0);
3459 	/*
3460 	 * g) Move the persistent reservation to the specified I_T nexus using
3461 	 *    the same scope and type as the persistent reservation released in
3462 	 *    item f); and
3463 	 */
3464 	dev->dev_pr_res_holder = dest_pr_reg;
3465 	dest_pr_reg->pr_res_holder = 1;
3466 	dest_pr_reg->pr_res_type = type;
3467 	pr_reg->pr_res_scope = scope;
3468 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3469 	/*
3470 	 * Increment PRGeneration for existing registrations..
3471 	 */
3472 	if (!new_reg)
3473 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3474 	spin_unlock(&dev->dev_reservation_lock);
3475 
3476 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3477 		" created new reservation holder TYPE: %s on object RTPI:"
3478 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3479 		core_scsi3_pr_dump_type(type), rtpi,
3480 		dest_pr_reg->pr_res_generation);
3481 	pr_debug("SPC-3 PR Successfully moved reservation from"
3482 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3483 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3484 		i_buf, dest_tf_ops->get_fabric_name(),
3485 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3486 		iport_ptr : "");
3487 	/*
3488 	 * It is now safe to release configfs group dependencies for destination
3489 	 * of Transport ID Initiator Device/Port Identifier
3490 	 */
3491 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3492 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3493 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3494 	/*
3495 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3496 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3497 	 */
3498 	if (unreg) {
3499 		spin_lock(&pr_tmpl->registration_lock);
3500 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3501 		spin_unlock(&pr_tmpl->registration_lock);
3502 	} else
3503 		core_scsi3_put_pr_reg(pr_reg);
3504 
3505 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3506 
3507 	transport_kunmap_data_sg(cmd);
3508 
3509 	core_scsi3_put_pr_reg(dest_pr_reg);
3510 	return 0;
3511 out:
3512 	if (buf)
3513 		transport_kunmap_data_sg(cmd);
3514 	if (dest_se_deve)
3515 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3516 	if (dest_node_acl)
3517 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3518 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3519 
3520 out_put_pr_reg:
3521 	core_scsi3_put_pr_reg(pr_reg);
3522 	return ret;
3523 }
3524 
3525 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3526 {
3527 	unsigned int __v1, __v2;
3528 
3529 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3530 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3531 
3532 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3533 }
3534 
3535 /*
3536  * See spc4r17 section 6.14 Table 170
3537  */
3538 sense_reason_t
3539 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3540 {
3541 	struct se_device *dev = cmd->se_dev;
3542 	unsigned char *cdb = &cmd->t_task_cdb[0];
3543 	unsigned char *buf;
3544 	u64 res_key, sa_res_key;
3545 	int sa, scope, type, aptpl;
3546 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3547 	sense_reason_t ret;
3548 
3549 	/*
3550 	 * Following spc2r20 5.5.1 Reservations overview:
3551 	 *
3552 	 * If a logical unit has been reserved by any RESERVE command and is
3553 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3554 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3555 	 * initiator or service action and shall terminate with a RESERVATION
3556 	 * CONFLICT status.
3557 	 */
3558 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3559 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3560 			" SPC-2 reservation is held, returning"
3561 			" RESERVATION_CONFLICT\n");
3562 		return TCM_RESERVATION_CONFLICT;
3563 	}
3564 
3565 	/*
3566 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3567 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3568 	 */
3569 	if (!cmd->se_sess)
3570 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3571 
3572 	if (cmd->data_length < 24) {
3573 		pr_warn("SPC-PR: Received PR OUT parameter list"
3574 			" length too small: %u\n", cmd->data_length);
3575 		return TCM_INVALID_PARAMETER_LIST;
3576 	}
3577 
3578 	/*
3579 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3580 	 */
3581 	sa = (cdb[1] & 0x1f);
3582 	scope = (cdb[2] & 0xf0);
3583 	type = (cdb[2] & 0x0f);
3584 
3585 	buf = transport_kmap_data_sg(cmd);
3586 	if (!buf)
3587 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3588 
3589 	/*
3590 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3591 	 */
3592 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3593 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3594 	/*
3595 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3596 	 * SCSI TransportIDs.
3597 	 */
3598 	if (sa != PRO_REGISTER_AND_MOVE) {
3599 		spec_i_pt = (buf[20] & 0x08);
3600 		all_tg_pt = (buf[20] & 0x04);
3601 		aptpl = (buf[20] & 0x01);
3602 	} else {
3603 		aptpl = (buf[17] & 0x01);
3604 		unreg = (buf[17] & 0x02);
3605 	}
3606 	/*
3607 	 * If the backend device has been configured to force APTPL metadata
3608 	 * write-out, go ahead and propigate aptpl=1 down now.
3609 	 */
3610 	if (dev->dev_attrib.force_pr_aptpl)
3611 		aptpl = 1;
3612 
3613 	transport_kunmap_data_sg(cmd);
3614 	buf = NULL;
3615 
3616 	/*
3617 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3618 	 */
3619 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER))
3620 		return TCM_INVALID_PARAMETER_LIST;
3621 
3622 	/*
3623 	 * From spc4r17 section 6.14:
3624 	 *
3625 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3626 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3627 	 * the command shall be terminated with CHECK CONDITION status, with
3628 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3629 	 * code set to PARAMETER LIST LENGTH ERROR.
3630 	 */
3631 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3632 	    (cmd->data_length != 24)) {
3633 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3634 			" list length: %u\n", cmd->data_length);
3635 		return TCM_INVALID_PARAMETER_LIST;
3636 	}
3637 
3638 	/*
3639 	 * (core_scsi3_emulate_pro_* function parameters
3640 	 * are defined by spc4r17 Table 174:
3641 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3642 	 */
3643 	switch (sa) {
3644 	case PRO_REGISTER:
3645 		ret = core_scsi3_emulate_pro_register(cmd,
3646 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3647 		break;
3648 	case PRO_RESERVE:
3649 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3650 		break;
3651 	case PRO_RELEASE:
3652 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3653 		break;
3654 	case PRO_CLEAR:
3655 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3656 		break;
3657 	case PRO_PREEMPT:
3658 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3659 					res_key, sa_res_key, PREEMPT);
3660 		break;
3661 	case PRO_PREEMPT_AND_ABORT:
3662 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3663 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3664 		break;
3665 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3666 		ret = core_scsi3_emulate_pro_register(cmd,
3667 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3668 		break;
3669 	case PRO_REGISTER_AND_MOVE:
3670 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3671 				sa_res_key, aptpl, unreg);
3672 		break;
3673 	default:
3674 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3675 			" action: 0x%02x\n", cdb[1] & 0x1f);
3676 		return TCM_INVALID_CDB_FIELD;
3677 	}
3678 
3679 	if (!ret)
3680 		target_complete_cmd(cmd, GOOD);
3681 	return ret;
3682 }
3683 
3684 /*
3685  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3686  *
3687  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3688  */
3689 static sense_reason_t
3690 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3691 {
3692 	struct se_device *dev = cmd->se_dev;
3693 	struct t10_pr_registration *pr_reg;
3694 	unsigned char *buf;
3695 	u32 add_len = 0, off = 8;
3696 
3697 	if (cmd->data_length < 8) {
3698 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3699 			" too small\n", cmd->data_length);
3700 		return TCM_INVALID_CDB_FIELD;
3701 	}
3702 
3703 	buf = transport_kmap_data_sg(cmd);
3704 	if (!buf)
3705 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3706 
3707 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3708 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3709 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3710 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3711 
3712 	spin_lock(&dev->t10_pr.registration_lock);
3713 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3714 			pr_reg_list) {
3715 		/*
3716 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3717 		 * next reservation key list descriptor.
3718 		 */
3719 		if ((add_len + 8) > (cmd->data_length - 8))
3720 			break;
3721 
3722 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3723 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3724 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3725 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3726 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3727 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3728 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3729 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3730 
3731 		add_len += 8;
3732 	}
3733 	spin_unlock(&dev->t10_pr.registration_lock);
3734 
3735 	buf[4] = ((add_len >> 24) & 0xff);
3736 	buf[5] = ((add_len >> 16) & 0xff);
3737 	buf[6] = ((add_len >> 8) & 0xff);
3738 	buf[7] = (add_len & 0xff);
3739 
3740 	transport_kunmap_data_sg(cmd);
3741 
3742 	return 0;
3743 }
3744 
3745 /*
3746  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3747  *
3748  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3749  */
3750 static sense_reason_t
3751 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3752 {
3753 	struct se_device *dev = cmd->se_dev;
3754 	struct t10_pr_registration *pr_reg;
3755 	unsigned char *buf;
3756 	u64 pr_res_key;
3757 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3758 
3759 	if (cmd->data_length < 8) {
3760 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3761 			" too small\n", cmd->data_length);
3762 		return TCM_INVALID_CDB_FIELD;
3763 	}
3764 
3765 	buf = transport_kmap_data_sg(cmd);
3766 	if (!buf)
3767 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3768 
3769 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3770 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3771 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3772 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3773 
3774 	spin_lock(&dev->dev_reservation_lock);
3775 	pr_reg = dev->dev_pr_res_holder;
3776 	if (pr_reg) {
3777 		/*
3778 		 * Set the hardcoded Additional Length
3779 		 */
3780 		buf[4] = ((add_len >> 24) & 0xff);
3781 		buf[5] = ((add_len >> 16) & 0xff);
3782 		buf[6] = ((add_len >> 8) & 0xff);
3783 		buf[7] = (add_len & 0xff);
3784 
3785 		if (cmd->data_length < 22)
3786 			goto err;
3787 
3788 		/*
3789 		 * Set the Reservation key.
3790 		 *
3791 		 * From spc4r17, section 5.7.10:
3792 		 * A persistent reservation holder has its reservation key
3793 		 * returned in the parameter data from a PERSISTENT
3794 		 * RESERVE IN command with READ RESERVATION service action as
3795 		 * follows:
3796 		 * a) For a persistent reservation of the type Write Exclusive
3797 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3798 		 *      the reservation key shall be set to zero; or
3799 		 * b) For all other persistent reservation types, the
3800 		 *    reservation key shall be set to the registered
3801 		 *    reservation key for the I_T nexus that holds the
3802 		 *    persistent reservation.
3803 		 */
3804 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3805 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3806 			pr_res_key = 0;
3807 		else
3808 			pr_res_key = pr_reg->pr_res_key;
3809 
3810 		buf[8] = ((pr_res_key >> 56) & 0xff);
3811 		buf[9] = ((pr_res_key >> 48) & 0xff);
3812 		buf[10] = ((pr_res_key >> 40) & 0xff);
3813 		buf[11] = ((pr_res_key >> 32) & 0xff);
3814 		buf[12] = ((pr_res_key >> 24) & 0xff);
3815 		buf[13] = ((pr_res_key >> 16) & 0xff);
3816 		buf[14] = ((pr_res_key >> 8) & 0xff);
3817 		buf[15] = (pr_res_key & 0xff);
3818 		/*
3819 		 * Set the SCOPE and TYPE
3820 		 */
3821 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3822 			  (pr_reg->pr_res_type & 0x0f);
3823 	}
3824 
3825 err:
3826 	spin_unlock(&dev->dev_reservation_lock);
3827 	transport_kunmap_data_sg(cmd);
3828 
3829 	return 0;
3830 }
3831 
3832 /*
3833  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3834  *
3835  * See spc4r17 section 6.13.4 Table 165
3836  */
3837 static sense_reason_t
3838 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3839 {
3840 	struct se_device *dev = cmd->se_dev;
3841 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3842 	unsigned char *buf;
3843 	u16 add_len = 8; /* Hardcoded to 8. */
3844 
3845 	if (cmd->data_length < 6) {
3846 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3847 			" %u too small\n", cmd->data_length);
3848 		return TCM_INVALID_CDB_FIELD;
3849 	}
3850 
3851 	buf = transport_kmap_data_sg(cmd);
3852 	if (!buf)
3853 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3854 
3855 	buf[0] = ((add_len >> 8) & 0xff);
3856 	buf[1] = (add_len & 0xff);
3857 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3858 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3859 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3860 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3861 	/*
3862 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3863 	 * set the TMV: Task Mask Valid bit.
3864 	 */
3865 	buf[3] |= 0x80;
3866 	/*
3867 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3868 	 */
3869 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3870 	/*
3871 	 * PTPL_A: Persistence across Target Power Loss Active bit
3872 	 */
3873 	if (pr_tmpl->pr_aptpl_active)
3874 		buf[3] |= 0x01;
3875 	/*
3876 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3877 	 */
3878 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3879 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3880 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3881 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3882 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3883 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3884 
3885 	transport_kunmap_data_sg(cmd);
3886 
3887 	return 0;
3888 }
3889 
3890 /*
3891  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3892  *
3893  * See spc4r17 section 6.13.5 Table 168 and 169
3894  */
3895 static sense_reason_t
3896 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3897 {
3898 	struct se_device *dev = cmd->se_dev;
3899 	struct se_node_acl *se_nacl;
3900 	struct se_portal_group *se_tpg;
3901 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3902 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3903 	unsigned char *buf;
3904 	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
3905 	u32 off = 8; /* off into first Full Status descriptor */
3906 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3907 	bool all_reg = false;
3908 
3909 	if (cmd->data_length < 8) {
3910 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3911 			" too small\n", cmd->data_length);
3912 		return TCM_INVALID_CDB_FIELD;
3913 	}
3914 
3915 	buf = transport_kmap_data_sg(cmd);
3916 	if (!buf)
3917 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3918 
3919 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3920 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3921 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3922 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3923 
3924 	spin_lock(&dev->dev_reservation_lock);
3925 	if (dev->dev_pr_res_holder) {
3926 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3927 
3928 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3929 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3930 			all_reg = true;
3931 			pr_res_type = pr_holder->pr_res_type;
3932 			pr_res_scope = pr_holder->pr_res_scope;
3933 		}
3934 	}
3935 	spin_unlock(&dev->dev_reservation_lock);
3936 
3937 	spin_lock(&pr_tmpl->registration_lock);
3938 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3939 			&pr_tmpl->registration_list, pr_reg_list) {
3940 
3941 		se_nacl = pr_reg->pr_reg_nacl;
3942 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3943 		add_desc_len = 0;
3944 
3945 		atomic_inc_mb(&pr_reg->pr_res_holders);
3946 		spin_unlock(&pr_tmpl->registration_lock);
3947 		/*
3948 		 * Determine expected length of $FABRIC_MOD specific
3949 		 * TransportID full status descriptor..
3950 		 */
3951 		exp_desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id_len(
3952 				se_tpg, se_nacl, pr_reg, &format_code);
3953 
3954 		if ((exp_desc_len + add_len) > cmd->data_length) {
3955 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3956 				" out of buffer: %d\n", cmd->data_length);
3957 			spin_lock(&pr_tmpl->registration_lock);
3958 			atomic_dec_mb(&pr_reg->pr_res_holders);
3959 			break;
3960 		}
3961 		/*
3962 		 * Set RESERVATION KEY
3963 		 */
3964 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3965 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3966 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3967 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3968 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3969 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3970 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3971 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3972 		off += 4; /* Skip Over Reserved area */
3973 
3974 		/*
3975 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3976 		 */
3977 		if (pr_reg->pr_reg_all_tg_pt)
3978 			buf[off] = 0x02;
3979 		/*
3980 		 * The struct se_lun pointer will be present for the
3981 		 * reservation holder for PR_HOLDER bit.
3982 		 *
3983 		 * Also, if this registration is the reservation
3984 		 * holder or there is an All Registrants reservation
3985 		 * active, fill in SCOPE and TYPE in the next byte.
3986 		 */
3987 		if (pr_reg->pr_res_holder) {
3988 			buf[off++] |= 0x01;
3989 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3990 				     (pr_reg->pr_res_type & 0x0f);
3991 		} else if (all_reg) {
3992 			buf[off++] |= 0x01;
3993 			buf[off++] = (pr_res_scope & 0xf0) |
3994 				     (pr_res_type & 0x0f);
3995 		} else {
3996 			off += 2;
3997 		}
3998 
3999 		off += 4; /* Skip over reserved area */
4000 		/*
4001 		 * From spc4r17 6.3.15:
4002 		 *
4003 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4004 		 * IDENTIFIER field contains the relative port identifier (see
4005 		 * 3.1.120) of the target port that is part of the I_T nexus
4006 		 * described by this full status descriptor. If the ALL_TG_PT
4007 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4008 		 * IDENTIFIER field are not defined by this standard.
4009 		 */
4010 		if (!pr_reg->pr_reg_all_tg_pt) {
4011 			struct se_port *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
4012 
4013 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
4014 			buf[off++] = (port->sep_rtpi & 0xff);
4015 		} else
4016 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
4017 
4018 		/*
4019 		 * Now, have the $FABRIC_MOD fill in the protocol identifier
4020 		 */
4021 		desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id(se_tpg,
4022 				se_nacl, pr_reg, &format_code, &buf[off+4]);
4023 
4024 		spin_lock(&pr_tmpl->registration_lock);
4025 		atomic_dec_mb(&pr_reg->pr_res_holders);
4026 		/*
4027 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4028 		 */
4029 		buf[off++] = ((desc_len >> 24) & 0xff);
4030 		buf[off++] = ((desc_len >> 16) & 0xff);
4031 		buf[off++] = ((desc_len >> 8) & 0xff);
4032 		buf[off++] = (desc_len & 0xff);
4033 		/*
4034 		 * Size of full desctipor header minus TransportID
4035 		 * containing $FABRIC_MOD specific) initiator device/port
4036 		 * WWN information.
4037 		 *
4038 		 *  See spc4r17 Section 6.13.5 Table 169
4039 		 */
4040 		add_desc_len = (24 + desc_len);
4041 
4042 		off += desc_len;
4043 		add_len += add_desc_len;
4044 	}
4045 	spin_unlock(&pr_tmpl->registration_lock);
4046 	/*
4047 	 * Set ADDITIONAL_LENGTH
4048 	 */
4049 	buf[4] = ((add_len >> 24) & 0xff);
4050 	buf[5] = ((add_len >> 16) & 0xff);
4051 	buf[6] = ((add_len >> 8) & 0xff);
4052 	buf[7] = (add_len & 0xff);
4053 
4054 	transport_kunmap_data_sg(cmd);
4055 
4056 	return 0;
4057 }
4058 
4059 sense_reason_t
4060 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4061 {
4062 	sense_reason_t ret;
4063 
4064 	/*
4065 	 * Following spc2r20 5.5.1 Reservations overview:
4066 	 *
4067 	 * If a logical unit has been reserved by any RESERVE command and is
4068 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4069 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4070 	 * initiator or service action and shall terminate with a RESERVATION
4071 	 * CONFLICT status.
4072 	 */
4073 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4074 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4075 			" SPC-2 reservation is held, returning"
4076 			" RESERVATION_CONFLICT\n");
4077 		return TCM_RESERVATION_CONFLICT;
4078 	}
4079 
4080 	switch (cmd->t_task_cdb[1] & 0x1f) {
4081 	case PRI_READ_KEYS:
4082 		ret = core_scsi3_pri_read_keys(cmd);
4083 		break;
4084 	case PRI_READ_RESERVATION:
4085 		ret = core_scsi3_pri_read_reservation(cmd);
4086 		break;
4087 	case PRI_REPORT_CAPABILITIES:
4088 		ret = core_scsi3_pri_report_capabilities(cmd);
4089 		break;
4090 	case PRI_READ_FULL_STATUS:
4091 		ret = core_scsi3_pri_read_full_status(cmd);
4092 		break;
4093 	default:
4094 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4095 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4096 		return TCM_INVALID_CDB_FIELD;
4097 	}
4098 
4099 	if (!ret)
4100 		target_complete_cmd(cmd, GOOD);
4101 	return ret;
4102 }
4103 
4104 sense_reason_t
4105 target_check_reservation(struct se_cmd *cmd)
4106 {
4107 	struct se_device *dev = cmd->se_dev;
4108 	sense_reason_t ret;
4109 
4110 	if (!cmd->se_sess)
4111 		return 0;
4112 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4113 		return 0;
4114 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
4115 		return 0;
4116 
4117 	spin_lock(&dev->dev_reservation_lock);
4118 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4119 		ret = target_scsi2_reservation_check(cmd);
4120 	else
4121 		ret = target_scsi3_pr_reservation_check(cmd);
4122 	spin_unlock(&dev->dev_reservation_lock);
4123 
4124 	return ret;
4125 }
4126