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/vmalloc.h>
31 #include <linux/file.h>
32 #include <linux/fcntl.h>
33 #include <linux/fs.h>
34 #include <scsi/scsi_proto.h>
35 #include <asm/unaligned.h>
36 
37 #include <target/target_core_base.h>
38 #include <target/target_core_backend.h>
39 #include <target/target_core_fabric.h>
40 
41 #include "target_core_internal.h"
42 #include "target_core_pr.h"
43 #include "target_core_ua.h"
44 
45 /*
46  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
47  */
48 struct pr_transport_id_holder {
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: %llu ->"
235 		" MAPPED LUN: %llu for %s\n",
236 		tpg->se_tpg_tfo->get_fabric_name(),
237 		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
238 		sess->se_node_acl->initiatorname);
239 
240 out_unlock:
241 	spin_unlock(&dev->dev_reservation_lock);
242 out:
243 	target_complete_cmd(cmd, GOOD);
244 	return 0;
245 }
246 
247 sense_reason_t
248 target_scsi2_reservation_reserve(struct se_cmd *cmd)
249 {
250 	struct se_device *dev = cmd->se_dev;
251 	struct se_session *sess = cmd->se_sess;
252 	struct se_portal_group *tpg;
253 	sense_reason_t ret = 0;
254 	int rc;
255 
256 	if ((cmd->t_task_cdb[1] & 0x01) &&
257 	    (cmd->t_task_cdb[1] & 0x02)) {
258 		pr_err("LongIO and Obsolete Bits set, returning 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: %llu %s\n",
281 			cmd->se_lun->unpacked_lun,
282 			dev->dev_reserved_node_acl->initiatorname);
283 		pr_err("Current attempt - LUN: %llu -> MAPPED LUN: %llu"
284 			" from %s \n", cmd->se_lun->unpacked_lun,
285 			cmd->orig_fe_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: %llu -> MAPPED LUN: %llu"
298 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
299 		cmd->se_lun->unpacked_lun, cmd->orig_fe_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(struct se_cmd *cmd, u32 pr_reg_type,
318 					bool isid_mismatch)
319 {
320 	unsigned char *cdb = cmd->t_task_cdb;
321 	struct se_session *se_sess = cmd->se_sess;
322 	struct se_node_acl *nacl = se_sess->se_node_acl;
323 	int other_cdb = 0;
324 	int registered_nexus = 0, ret = 1; /* Conflict by default */
325 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
326 	int we = 0; /* Write Exclusive */
327 	int legacy = 0; /* Act like a legacy device and return
328 			 * RESERVATION CONFLICT on some CDBs */
329 
330 	if (isid_mismatch) {
331 		registered_nexus = 0;
332 	} else {
333 		struct se_dev_entry *se_deve;
334 
335 		rcu_read_lock();
336 		se_deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
337 		if (se_deve)
338 			registered_nexus = test_bit(DEF_PR_REG_ACTIVE,
339 						    &se_deve->deve_flags);
340 		rcu_read_unlock();
341 	}
342 
343 	switch (pr_reg_type) {
344 	case PR_TYPE_WRITE_EXCLUSIVE:
345 		we = 1;
346 	case PR_TYPE_EXCLUSIVE_ACCESS:
347 		/*
348 		 * Some commands are only allowed for the persistent reservation
349 		 * holder.
350 		 */
351 		break;
352 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
353 		we = 1;
354 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
355 		/*
356 		 * Some commands are only allowed for registered I_T Nexuses.
357 		 */
358 		reg_only = 1;
359 		break;
360 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
361 		we = 1;
362 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
363 		/*
364 		 * Each registered I_T Nexus is a reservation holder.
365 		 */
366 		all_reg = 1;
367 		break;
368 	default:
369 		return -EINVAL;
370 	}
371 	/*
372 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
373 	 */
374 	switch (cdb[0]) {
375 	case SECURITY_PROTOCOL_IN:
376 		if (registered_nexus)
377 			return 0;
378 		ret = (we) ? 0 : 1;
379 		break;
380 	case MODE_SENSE:
381 	case MODE_SENSE_10:
382 	case READ_ATTRIBUTE:
383 	case READ_BUFFER:
384 	case RECEIVE_DIAGNOSTIC:
385 		if (legacy) {
386 			ret = 1;
387 			break;
388 		}
389 		if (registered_nexus) {
390 			ret = 0;
391 			break;
392 		}
393 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
394 		break;
395 	case PERSISTENT_RESERVE_OUT:
396 		/*
397 		 * This follows PERSISTENT_RESERVE_OUT service actions that
398 		 * are allowed in the presence of various reservations.
399 		 * See spc4r17, table 46
400 		 */
401 		switch (cdb[1] & 0x1f) {
402 		case PRO_CLEAR:
403 		case PRO_PREEMPT:
404 		case PRO_PREEMPT_AND_ABORT:
405 			ret = (registered_nexus) ? 0 : 1;
406 			break;
407 		case PRO_REGISTER:
408 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
409 			ret = 0;
410 			break;
411 		case PRO_REGISTER_AND_MOVE:
412 		case PRO_RESERVE:
413 			ret = 1;
414 			break;
415 		case PRO_RELEASE:
416 			ret = (registered_nexus) ? 0 : 1;
417 			break;
418 		default:
419 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
420 				" action: 0x%02x\n", cdb[1] & 0x1f);
421 			return -EINVAL;
422 		}
423 		break;
424 	case RELEASE:
425 	case RELEASE_10:
426 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
427 		ret = 0;
428 		break;
429 	case RESERVE:
430 	case RESERVE_10:
431 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
432 		ret = 0;
433 		break;
434 	case TEST_UNIT_READY:
435 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
436 		break;
437 	case MAINTENANCE_IN:
438 		switch (cdb[1] & 0x1f) {
439 		case MI_MANAGEMENT_PROTOCOL_IN:
440 			if (registered_nexus) {
441 				ret = 0;
442 				break;
443 			}
444 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
445 			break;
446 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
447 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
448 			if (legacy) {
449 				ret = 1;
450 				break;
451 			}
452 			if (registered_nexus) {
453 				ret = 0;
454 				break;
455 			}
456 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
457 			break;
458 		case MI_REPORT_ALIASES:
459 		case MI_REPORT_IDENTIFYING_INFORMATION:
460 		case MI_REPORT_PRIORITY:
461 		case MI_REPORT_TARGET_PGS:
462 		case MI_REPORT_TIMESTAMP:
463 			ret = 0; /* Allowed */
464 			break;
465 		default:
466 			pr_err("Unknown MI Service Action: 0x%02x\n",
467 				(cdb[1] & 0x1f));
468 			return -EINVAL;
469 		}
470 		break;
471 	case ACCESS_CONTROL_IN:
472 	case ACCESS_CONTROL_OUT:
473 	case INQUIRY:
474 	case LOG_SENSE:
475 	case SERVICE_ACTION_IN_12:
476 	case REPORT_LUNS:
477 	case REQUEST_SENSE:
478 	case PERSISTENT_RESERVE_IN:
479 		ret = 0; /*/ Allowed CDBs */
480 		break;
481 	default:
482 		other_cdb = 1;
483 		break;
484 	}
485 	/*
486 	 * Case where the CDB is explicitly allowed in the above switch
487 	 * statement.
488 	 */
489 	if (!ret && !other_cdb) {
490 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
491 			" reservation holder\n", cdb[0],
492 			core_scsi3_pr_dump_type(pr_reg_type));
493 
494 		return ret;
495 	}
496 	/*
497 	 * Check if write exclusive initiator ports *NOT* holding the
498 	 * WRITE_EXCLUSIVE_* reservation.
499 	 */
500 	if (we && !registered_nexus) {
501 		if (cmd->data_direction == DMA_TO_DEVICE) {
502 			/*
503 			 * Conflict for write exclusive
504 			 */
505 			pr_debug("%s Conflict for unregistered nexus"
506 				" %s CDB: 0x%02x to %s reservation\n",
507 				transport_dump_cmd_direction(cmd),
508 				se_sess->se_node_acl->initiatorname, cdb[0],
509 				core_scsi3_pr_dump_type(pr_reg_type));
510 			return 1;
511 		} else {
512 			/*
513 			 * Allow non WRITE CDBs for all Write Exclusive
514 			 * PR TYPEs to pass for registered and
515 			 * non-registered_nexuxes NOT holding the reservation.
516 			 *
517 			 * We only make noise for the unregisterd nexuses,
518 			 * as we expect registered non-reservation holding
519 			 * nexuses to issue CDBs.
520 			 */
521 
522 			if (!registered_nexus) {
523 				pr_debug("Allowing implicit CDB: 0x%02x"
524 					" for %s reservation on unregistered"
525 					" nexus\n", cdb[0],
526 					core_scsi3_pr_dump_type(pr_reg_type));
527 			}
528 
529 			return 0;
530 		}
531 	} else if ((reg_only) || (all_reg)) {
532 		if (registered_nexus) {
533 			/*
534 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
535 			 * allow commands from registered nexuses.
536 			 */
537 
538 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
539 				" reservation\n", cdb[0],
540 				core_scsi3_pr_dump_type(pr_reg_type));
541 
542 			return 0;
543 		}
544        } else if (we && registered_nexus) {
545                /*
546                 * Reads are allowed for Write Exclusive locks
547                 * from all registrants.
548                 */
549                if (cmd->data_direction == DMA_FROM_DEVICE) {
550                        pr_debug("Allowing READ CDB: 0x%02x for %s"
551                                " reservation\n", cdb[0],
552                                core_scsi3_pr_dump_type(pr_reg_type));
553 
554                        return 0;
555                }
556 	}
557 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
558 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
559 		(registered_nexus) ? "" : "un",
560 		se_sess->se_node_acl->initiatorname, cdb[0],
561 		core_scsi3_pr_dump_type(pr_reg_type));
562 
563 	return 1; /* Conflict by default */
564 }
565 
566 static sense_reason_t
567 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
568 {
569 	struct se_device *dev = cmd->se_dev;
570 	struct se_session *sess = cmd->se_sess;
571 	u32 pr_reg_type;
572 	bool isid_mismatch = false;
573 
574 	if (!dev->dev_pr_res_holder)
575 		return 0;
576 
577 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
578 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
579 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
580 		goto check_nonholder;
581 
582 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
583 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
584 		    sess->sess_bin_isid) {
585 			isid_mismatch = true;
586 			goto check_nonholder;
587 		}
588 	}
589 
590 	return 0;
591 
592 check_nonholder:
593 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type, isid_mismatch))
594 		return TCM_RESERVATION_CONFLICT;
595 	return 0;
596 }
597 
598 static u32 core_scsi3_pr_generation(struct se_device *dev)
599 {
600 	u32 prg;
601 
602 	/*
603 	 * PRGeneration field shall contain the value of a 32-bit wrapping
604 	 * counter mainted by the device server.
605 	 *
606 	 * Note that this is done regardless of Active Persist across
607 	 * Target PowerLoss (APTPL)
608 	 *
609 	 * See spc4r17 section 6.3.12 READ_KEYS service action
610 	 */
611 	spin_lock(&dev->dev_reservation_lock);
612 	prg = dev->t10_pr.pr_generation++;
613 	spin_unlock(&dev->dev_reservation_lock);
614 
615 	return prg;
616 }
617 
618 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
619 	struct se_device *dev,
620 	struct se_node_acl *nacl,
621 	struct se_lun *lun,
622 	struct se_dev_entry *dest_deve,
623 	u64 mapped_lun,
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 	/*
645 	 * For destination registrations for ALL_TG_PT=1 and SPEC_I_PT=1,
646 	 * the se_dev_entry->pr_ref will have been already obtained by
647 	 * core_get_se_deve_from_rtpi() or __core_scsi3_alloc_registration().
648 	 *
649 	 * Otherwise, locate se_dev_entry now and obtain a reference until
650 	 * registration completes in __core_scsi3_add_registration().
651 	 */
652 	if (dest_deve) {
653 		pr_reg->pr_reg_deve = dest_deve;
654 	} else {
655 		rcu_read_lock();
656 		pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
657 		if (!pr_reg->pr_reg_deve) {
658 			rcu_read_unlock();
659 			pr_err("Unable to locate PR deve %s mapped_lun: %llu\n",
660 				nacl->initiatorname, mapped_lun);
661 			kmem_cache_free(t10_pr_reg_cache, pr_reg);
662 			return NULL;
663 		}
664 		kref_get(&pr_reg->pr_reg_deve->pr_kref);
665 		rcu_read_unlock();
666 	}
667 	pr_reg->pr_res_mapped_lun = mapped_lun;
668 	pr_reg->pr_aptpl_target_lun = lun->unpacked_lun;
669 	pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
670 	pr_reg->pr_res_key = sa_res_key;
671 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
672 	pr_reg->pr_reg_aptpl = aptpl;
673 	/*
674 	 * If an ISID value for this SCSI Initiator Port exists,
675 	 * save it to the registration now.
676 	 */
677 	if (isid != NULL) {
678 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
679 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
680 		pr_reg->isid_present_at_reg = 1;
681 	}
682 
683 	return pr_reg;
684 }
685 
686 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
687 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
688 
689 /*
690  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
691  * modes.
692  */
693 static struct t10_pr_registration *__core_scsi3_alloc_registration(
694 	struct se_device *dev,
695 	struct se_node_acl *nacl,
696 	struct se_lun *lun,
697 	struct se_dev_entry *deve,
698 	u64 mapped_lun,
699 	unsigned char *isid,
700 	u64 sa_res_key,
701 	int all_tg_pt,
702 	int aptpl)
703 {
704 	struct se_dev_entry *deve_tmp;
705 	struct se_node_acl *nacl_tmp;
706 	struct se_lun_acl *lacl_tmp;
707 	struct se_lun *lun_tmp, *next, *dest_lun;
708 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
709 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
710 	int ret;
711 	/*
712 	 * Create a registration for the I_T Nexus upon which the
713 	 * PROUT REGISTER was received.
714 	 */
715 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, lun, deve, mapped_lun,
716 						    isid, sa_res_key, all_tg_pt,
717 						    aptpl);
718 	if (!pr_reg)
719 		return NULL;
720 	/*
721 	 * Return pointer to pr_reg for ALL_TG_PT=0
722 	 */
723 	if (!all_tg_pt)
724 		return pr_reg;
725 	/*
726 	 * Create list of matching SCSI Initiator Port registrations
727 	 * for ALL_TG_PT=1
728 	 */
729 	spin_lock(&dev->se_port_lock);
730 	list_for_each_entry_safe(lun_tmp, next, &dev->dev_sep_list, lun_dev_link) {
731 		if (!percpu_ref_tryget_live(&lun_tmp->lun_ref))
732 			continue;
733 		spin_unlock(&dev->se_port_lock);
734 
735 		spin_lock(&lun_tmp->lun_deve_lock);
736 		list_for_each_entry(deve_tmp, &lun_tmp->lun_deve_list, lun_link) {
737 			/*
738 			 * This pointer will be NULL for demo mode MappedLUNs
739 			 * that have not been make explicit via a ConfigFS
740 			 * MappedLUN group for the SCSI Initiator Node ACL.
741 			 */
742 			if (!deve_tmp->se_lun_acl)
743 				continue;
744 
745 			lacl_tmp = rcu_dereference_check(deve_tmp->se_lun_acl,
746 						lockdep_is_held(&lun_tmp->lun_deve_lock));
747 			nacl_tmp = lacl_tmp->se_lun_nacl;
748 			/*
749 			 * Skip the matching struct se_node_acl that is allocated
750 			 * above..
751 			 */
752 			if (nacl == nacl_tmp)
753 				continue;
754 			/*
755 			 * Only perform PR registrations for target ports on
756 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
757 			 * arrived.
758 			 */
759 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
760 				continue;
761 			/*
762 			 * Look for a matching Initiator Node ACL in ASCII format
763 			 */
764 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
765 				continue;
766 
767 			kref_get(&deve_tmp->pr_kref);
768 			spin_unlock(&lun_tmp->lun_deve_lock);
769 			/*
770 			 * Grab a configfs group dependency that is released
771 			 * for the exception path at label out: below, or upon
772 			 * completion of adding ALL_TG_PT=1 registrations in
773 			 * __core_scsi3_add_registration()
774 			 */
775 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
776 			if (ret < 0) {
777 				pr_err("core_scsi3_lunacl_depend"
778 						"_item() failed\n");
779 				percpu_ref_put(&lun_tmp->lun_ref);
780 				kref_put(&deve_tmp->pr_kref, target_pr_kref_release);
781 				goto out;
782 			}
783 			/*
784 			 * Located a matching SCSI Initiator Port on a different
785 			 * port, allocate the pr_reg_atp and attach it to the
786 			 * pr_reg->pr_reg_atp_list that will be processed once
787 			 * the original *pr_reg is processed in
788 			 * __core_scsi3_add_registration()
789 			 */
790 			dest_lun = rcu_dereference_check(deve_tmp->se_lun,
791 				kref_read(&deve_tmp->pr_kref) != 0);
792 
793 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
794 						nacl_tmp, dest_lun, deve_tmp,
795 						deve_tmp->mapped_lun, NULL,
796 						sa_res_key, all_tg_pt, aptpl);
797 			if (!pr_reg_atp) {
798 				percpu_ref_put(&lun_tmp->lun_ref);
799 				core_scsi3_lunacl_undepend_item(deve_tmp);
800 				goto out;
801 			}
802 
803 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
804 				      &pr_reg->pr_reg_atp_list);
805 			spin_lock(&lun_tmp->lun_deve_lock);
806 		}
807 		spin_unlock(&lun_tmp->lun_deve_lock);
808 
809 		spin_lock(&dev->se_port_lock);
810 		percpu_ref_put(&lun_tmp->lun_ref);
811 	}
812 	spin_unlock(&dev->se_port_lock);
813 
814 	return pr_reg;
815 out:
816 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
817 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
818 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
819 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
820 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
821 	}
822 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
823 	return NULL;
824 }
825 
826 int core_scsi3_alloc_aptpl_registration(
827 	struct t10_reservation *pr_tmpl,
828 	u64 sa_res_key,
829 	unsigned char *i_port,
830 	unsigned char *isid,
831 	u64 mapped_lun,
832 	unsigned char *t_port,
833 	u16 tpgt,
834 	u64 target_lun,
835 	int res_holder,
836 	int all_tg_pt,
837 	u8 type)
838 {
839 	struct t10_pr_registration *pr_reg;
840 
841 	if (!i_port || !t_port || !sa_res_key) {
842 		pr_err("Illegal parameters for APTPL registration\n");
843 		return -EINVAL;
844 	}
845 
846 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
847 	if (!pr_reg) {
848 		pr_err("Unable to allocate struct t10_pr_registration\n");
849 		return -ENOMEM;
850 	}
851 
852 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
853 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
854 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
855 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
856 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
857 	atomic_set(&pr_reg->pr_res_holders, 0);
858 	pr_reg->pr_reg_nacl = NULL;
859 	pr_reg->pr_reg_deve = NULL;
860 	pr_reg->pr_res_mapped_lun = mapped_lun;
861 	pr_reg->pr_aptpl_target_lun = target_lun;
862 	pr_reg->pr_res_key = sa_res_key;
863 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
864 	pr_reg->pr_reg_aptpl = 1;
865 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
866 	pr_reg->pr_res_type = type;
867 	/*
868 	 * If an ISID value had been saved in APTPL metadata for this
869 	 * SCSI Initiator Port, restore it now.
870 	 */
871 	if (isid != NULL) {
872 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
873 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
874 		pr_reg->isid_present_at_reg = 1;
875 	}
876 	/*
877 	 * Copy the i_port and t_port information from caller.
878 	 */
879 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
880 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
881 	pr_reg->pr_reg_tpgt = tpgt;
882 	/*
883 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
884 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
885 	 * the Initiator Node LUN ACL from the fabric module is created for
886 	 * this registration.
887 	 */
888 	pr_reg->pr_res_holder = res_holder;
889 
890 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
891 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
892 			" metadata\n", (res_holder) ? "+reservation" : "");
893 	return 0;
894 }
895 
896 static void core_scsi3_aptpl_reserve(
897 	struct se_device *dev,
898 	struct se_portal_group *tpg,
899 	struct se_node_acl *node_acl,
900 	struct t10_pr_registration *pr_reg)
901 {
902 	char i_buf[PR_REG_ISID_ID_LEN];
903 
904 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
905 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
906 
907 	spin_lock(&dev->dev_reservation_lock);
908 	dev->dev_pr_res_holder = pr_reg;
909 	spin_unlock(&dev->dev_reservation_lock);
910 
911 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
912 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
913 		tpg->se_tpg_tfo->get_fabric_name(),
914 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
915 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
916 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
917 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
918 		i_buf);
919 }
920 
921 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
922 				struct t10_pr_registration *, enum register_type, int);
923 
924 static int __core_scsi3_check_aptpl_registration(
925 	struct se_device *dev,
926 	struct se_portal_group *tpg,
927 	struct se_lun *lun,
928 	u64 target_lun,
929 	struct se_node_acl *nacl,
930 	u64 mapped_lun)
931 {
932 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
933 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
934 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
935 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
936 	u16 tpgt;
937 
938 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
939 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
940 	/*
941 	 * Copy Initiator Port information from struct se_node_acl
942 	 */
943 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
944 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
945 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
946 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
947 	/*
948 	 * Look for the matching registrations+reservation from those
949 	 * created from APTPL metadata.  Note that multiple registrations
950 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
951 	 * TransportIDs.
952 	 */
953 	spin_lock(&pr_tmpl->aptpl_reg_lock);
954 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
955 				pr_reg_aptpl_list) {
956 
957 		if (!strcmp(pr_reg->pr_iport, i_port) &&
958 		     (pr_reg->pr_res_mapped_lun == mapped_lun) &&
959 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
960 		     (pr_reg->pr_reg_tpgt == tpgt) &&
961 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
962 			/*
963 			 * Obtain the ->pr_reg_deve pointer + reference, that
964 			 * is released by __core_scsi3_add_registration() below.
965 			 */
966 			rcu_read_lock();
967 			pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
968 			if (!pr_reg->pr_reg_deve) {
969 				pr_err("Unable to locate PR APTPL %s mapped_lun:"
970 					" %llu\n", nacl->initiatorname, mapped_lun);
971 				rcu_read_unlock();
972 				continue;
973 			}
974 			kref_get(&pr_reg->pr_reg_deve->pr_kref);
975 			rcu_read_unlock();
976 
977 			pr_reg->pr_reg_nacl = nacl;
978 			pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
979 			list_del(&pr_reg->pr_reg_aptpl_list);
980 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
981 			/*
982 			 * At this point all of the pointers in *pr_reg will
983 			 * be setup, so go ahead and add the registration.
984 			 */
985 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
986 			/*
987 			 * If this registration is the reservation holder,
988 			 * make that happen now..
989 			 */
990 			if (pr_reg->pr_res_holder)
991 				core_scsi3_aptpl_reserve(dev, tpg,
992 						nacl, pr_reg);
993 			/*
994 			 * Reenable pr_aptpl_active to accept new metadata
995 			 * updates once the SCSI device is active again..
996 			 */
997 			spin_lock(&pr_tmpl->aptpl_reg_lock);
998 			pr_tmpl->pr_aptpl_active = 1;
999 		}
1000 	}
1001 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1002 
1003 	return 0;
1004 }
1005 
1006 int core_scsi3_check_aptpl_registration(
1007 	struct se_device *dev,
1008 	struct se_portal_group *tpg,
1009 	struct se_lun *lun,
1010 	struct se_node_acl *nacl,
1011 	u64 mapped_lun)
1012 {
1013 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
1014 		return 0;
1015 
1016 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
1017 						     lun->unpacked_lun, nacl,
1018 						     mapped_lun);
1019 }
1020 
1021 static void __core_scsi3_dump_registration(
1022 	const struct target_core_fabric_ops *tfo,
1023 	struct se_device *dev,
1024 	struct se_node_acl *nacl,
1025 	struct t10_pr_registration *pr_reg,
1026 	enum register_type register_type)
1027 {
1028 	struct se_portal_group *se_tpg = nacl->se_tpg;
1029 	char i_buf[PR_REG_ISID_ID_LEN];
1030 
1031 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
1032 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1033 
1034 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1035 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == REGISTER_AND_MOVE) ?
1036 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
1037 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1038 		i_buf);
1039 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1040 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
1041 		tfo->tpg_get_tag(se_tpg));
1042 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1043 		" Port(s)\n",  tfo->get_fabric_name(),
1044 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1045 		dev->transport->name);
1046 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1047 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
1048 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1049 		pr_reg->pr_reg_aptpl);
1050 }
1051 
1052 static void __core_scsi3_add_registration(
1053 	struct se_device *dev,
1054 	struct se_node_acl *nacl,
1055 	struct t10_pr_registration *pr_reg,
1056 	enum register_type register_type,
1057 	int register_move)
1058 {
1059 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1060 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1061 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1062 	struct se_dev_entry *deve;
1063 
1064 	/*
1065 	 * Increment PRgeneration counter for struct se_device upon a successful
1066 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1067 	 *
1068 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1069 	 * action, the struct se_device->dev_reservation_lock will already be held,
1070 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1071 	 * for the REGISTER.
1072 	 */
1073 	pr_reg->pr_res_generation = (register_move) ?
1074 			dev->t10_pr.pr_generation++ :
1075 			core_scsi3_pr_generation(dev);
1076 
1077 	spin_lock(&pr_tmpl->registration_lock);
1078 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1079 
1080 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1081 	spin_unlock(&pr_tmpl->registration_lock);
1082 	/*
1083 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1084 	 */
1085 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1086 		goto out;
1087 	/*
1088 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1089 	 * allocated in __core_scsi3_alloc_registration()
1090 	 */
1091 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1092 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1093 		struct se_node_acl *nacl_tmp = pr_reg_tmp->pr_reg_nacl;
1094 
1095 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1096 
1097 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1098 
1099 		spin_lock(&pr_tmpl->registration_lock);
1100 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1101 			      &pr_tmpl->registration_list);
1102 
1103 		__core_scsi3_dump_registration(tfo, dev, nacl_tmp, pr_reg_tmp,
1104 					       register_type);
1105 		spin_unlock(&pr_tmpl->registration_lock);
1106 		/*
1107 		 * Drop configfs group dependency reference and deve->pr_kref
1108 		 * obtained from  __core_scsi3_alloc_registration() code.
1109 		 */
1110 		rcu_read_lock();
1111 		deve = pr_reg_tmp->pr_reg_deve;
1112 		if (deve) {
1113 			set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1114 			core_scsi3_lunacl_undepend_item(deve);
1115 			pr_reg_tmp->pr_reg_deve = NULL;
1116 		}
1117 		rcu_read_unlock();
1118 	}
1119 out:
1120 	/*
1121 	 * Drop deve->pr_kref obtained in __core_scsi3_do_alloc_registration()
1122 	 */
1123 	rcu_read_lock();
1124 	deve = pr_reg->pr_reg_deve;
1125 	if (deve) {
1126 		set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1127 		kref_put(&deve->pr_kref, target_pr_kref_release);
1128 		pr_reg->pr_reg_deve = NULL;
1129 	}
1130 	rcu_read_unlock();
1131 }
1132 
1133 static int core_scsi3_alloc_registration(
1134 	struct se_device *dev,
1135 	struct se_node_acl *nacl,
1136 	struct se_lun *lun,
1137 	struct se_dev_entry *deve,
1138 	u64 mapped_lun,
1139 	unsigned char *isid,
1140 	u64 sa_res_key,
1141 	int all_tg_pt,
1142 	int aptpl,
1143 	enum register_type register_type,
1144 	int register_move)
1145 {
1146 	struct t10_pr_registration *pr_reg;
1147 
1148 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, lun, deve, mapped_lun,
1149 						 isid, sa_res_key, all_tg_pt,
1150 						 aptpl);
1151 	if (!pr_reg)
1152 		return -EPERM;
1153 
1154 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1155 			register_type, register_move);
1156 	return 0;
1157 }
1158 
1159 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1160 	struct se_device *dev,
1161 	struct se_node_acl *nacl,
1162 	unsigned char *isid)
1163 {
1164 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1165 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1166 	struct se_portal_group *tpg;
1167 
1168 	spin_lock(&pr_tmpl->registration_lock);
1169 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1170 			&pr_tmpl->registration_list, pr_reg_list) {
1171 		/*
1172 		 * First look for a matching struct se_node_acl
1173 		 */
1174 		if (pr_reg->pr_reg_nacl != nacl)
1175 			continue;
1176 
1177 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1178 		/*
1179 		 * If this registration does NOT contain a fabric provided
1180 		 * ISID, then we have found a match.
1181 		 */
1182 		if (!pr_reg->isid_present_at_reg) {
1183 			/*
1184 			 * Determine if this SCSI device server requires that
1185 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1186 			 * for fabric modules (iSCSI) requiring them.
1187 			 */
1188 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1189 				if (dev->dev_attrib.enforce_pr_isids)
1190 					continue;
1191 			}
1192 			atomic_inc_mb(&pr_reg->pr_res_holders);
1193 			spin_unlock(&pr_tmpl->registration_lock);
1194 			return pr_reg;
1195 		}
1196 		/*
1197 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1198 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1199 		 * matching ISID to be provided by the local SCSI Initiator Port.
1200 		 */
1201 		if (!isid)
1202 			continue;
1203 		if (strcmp(isid, pr_reg->pr_reg_isid))
1204 			continue;
1205 
1206 		atomic_inc_mb(&pr_reg->pr_res_holders);
1207 		spin_unlock(&pr_tmpl->registration_lock);
1208 		return pr_reg;
1209 	}
1210 	spin_unlock(&pr_tmpl->registration_lock);
1211 
1212 	return NULL;
1213 }
1214 
1215 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1216 	struct se_device *dev,
1217 	struct se_node_acl *nacl,
1218 	struct se_session *sess)
1219 {
1220 	struct se_portal_group *tpg = nacl->se_tpg;
1221 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1222 
1223 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1224 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1225 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1226 					PR_REG_ISID_LEN);
1227 		isid_ptr = &buf[0];
1228 	}
1229 
1230 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1231 }
1232 
1233 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1234 {
1235 	atomic_dec_mb(&pr_reg->pr_res_holders);
1236 }
1237 
1238 static int core_scsi3_check_implicit_release(
1239 	struct se_device *dev,
1240 	struct t10_pr_registration *pr_reg)
1241 {
1242 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1243 	struct t10_pr_registration *pr_res_holder;
1244 	int ret = 0;
1245 
1246 	spin_lock(&dev->dev_reservation_lock);
1247 	pr_res_holder = dev->dev_pr_res_holder;
1248 	if (!pr_res_holder) {
1249 		spin_unlock(&dev->dev_reservation_lock);
1250 		return ret;
1251 	}
1252 	if (pr_res_holder == pr_reg) {
1253 		/*
1254 		 * Perform an implicit RELEASE if the registration that
1255 		 * is being released is holding the reservation.
1256 		 *
1257 		 * From spc4r17, section 5.7.11.1:
1258 		 *
1259 		 * e) If the I_T nexus is the persistent reservation holder
1260 		 *    and the persistent reservation is not an all registrants
1261 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1262 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1263 		 *    service action with the SERVICE ACTION RESERVATION KEY
1264 		 *    field set to zero (see 5.7.11.3).
1265 		 */
1266 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1267 		ret = 1;
1268 		/*
1269 		 * For 'All Registrants' reservation types, all existing
1270 		 * registrations are still processed as reservation holders
1271 		 * in core_scsi3_pr_seq_non_holder() after the initial
1272 		 * reservation holder is implicitly released here.
1273 		 */
1274 	} else if (pr_reg->pr_reg_all_tg_pt &&
1275 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1276 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1277 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1278 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1279 			" UNREGISTER while existing reservation with matching"
1280 			" key 0x%016Lx is present from another SCSI Initiator"
1281 			" Port\n", pr_reg->pr_res_key);
1282 		ret = -EPERM;
1283 	}
1284 	spin_unlock(&dev->dev_reservation_lock);
1285 
1286 	return ret;
1287 }
1288 
1289 /*
1290  * Called with struct t10_reservation->registration_lock held.
1291  */
1292 static void __core_scsi3_free_registration(
1293 	struct se_device *dev,
1294 	struct t10_pr_registration *pr_reg,
1295 	struct list_head *preempt_and_abort_list,
1296 	int dec_holders)
1297 	__releases(&pr_tmpl->registration_lock)
1298 	__acquires(&pr_tmpl->registration_lock)
1299 {
1300 	const struct target_core_fabric_ops *tfo =
1301 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1302 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1303 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1304 	struct se_dev_entry *deve;
1305 	char i_buf[PR_REG_ISID_ID_LEN];
1306 
1307 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1308 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1309 
1310 	if (!list_empty(&pr_reg->pr_reg_list))
1311 		list_del(&pr_reg->pr_reg_list);
1312 	/*
1313 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1314 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1315 	 */
1316 	if (dec_holders)
1317 		core_scsi3_put_pr_reg(pr_reg);
1318 
1319 	spin_unlock(&pr_tmpl->registration_lock);
1320 	/*
1321 	 * Wait until all reference from any other I_T nexuses for this
1322 	 * *pr_reg have been released.  Because list_del() is called above,
1323 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1324 	 * count back to zero, and we release *pr_reg.
1325 	 */
1326 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1327 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1328 				tfo->get_fabric_name());
1329 		cpu_relax();
1330 	}
1331 
1332 	rcu_read_lock();
1333 	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
1334 	if (deve)
1335 		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1336 	rcu_read_unlock();
1337 
1338 	spin_lock(&pr_tmpl->registration_lock);
1339 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1340 		" Node: %s%s\n", tfo->get_fabric_name(),
1341 		pr_reg->pr_reg_nacl->initiatorname,
1342 		i_buf);
1343 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1344 		" Port(s)\n", tfo->get_fabric_name(),
1345 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1346 		dev->transport->name);
1347 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1348 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1349 		pr_reg->pr_res_generation);
1350 
1351 	if (!preempt_and_abort_list) {
1352 		pr_reg->pr_reg_deve = NULL;
1353 		pr_reg->pr_reg_nacl = NULL;
1354 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1355 		return;
1356 	}
1357 	/*
1358 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1359 	 * are released once the ABORT_TASK_SET has completed..
1360 	 */
1361 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1362 }
1363 
1364 void core_scsi3_free_pr_reg_from_nacl(
1365 	struct se_device *dev,
1366 	struct se_node_acl *nacl)
1367 {
1368 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1369 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1370 	bool free_reg = false;
1371 	/*
1372 	 * If the passed se_node_acl matches the reservation holder,
1373 	 * release the reservation.
1374 	 */
1375 	spin_lock(&dev->dev_reservation_lock);
1376 	pr_res_holder = dev->dev_pr_res_holder;
1377 	if ((pr_res_holder != NULL) &&
1378 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1379 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1380 		free_reg = true;
1381 	}
1382 	spin_unlock(&dev->dev_reservation_lock);
1383 	/*
1384 	 * Release any registration associated with the struct se_node_acl.
1385 	 */
1386 	spin_lock(&pr_tmpl->registration_lock);
1387 	if (pr_res_holder && free_reg)
1388 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1389 
1390 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1391 			&pr_tmpl->registration_list, pr_reg_list) {
1392 
1393 		if (pr_reg->pr_reg_nacl != nacl)
1394 			continue;
1395 
1396 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1397 	}
1398 	spin_unlock(&pr_tmpl->registration_lock);
1399 }
1400 
1401 void core_scsi3_free_all_registrations(
1402 	struct se_device *dev)
1403 {
1404 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1405 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1406 
1407 	spin_lock(&dev->dev_reservation_lock);
1408 	pr_res_holder = dev->dev_pr_res_holder;
1409 	if (pr_res_holder != NULL) {
1410 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1411 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1412 						  pr_res_holder, 0, 0);
1413 	}
1414 	spin_unlock(&dev->dev_reservation_lock);
1415 
1416 	spin_lock(&pr_tmpl->registration_lock);
1417 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1418 			&pr_tmpl->registration_list, pr_reg_list) {
1419 
1420 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1421 	}
1422 	spin_unlock(&pr_tmpl->registration_lock);
1423 
1424 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1425 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1426 				pr_reg_aptpl_list) {
1427 		list_del(&pr_reg->pr_reg_aptpl_list);
1428 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1429 	}
1430 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1431 }
1432 
1433 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1434 {
1435 	return target_depend_item(&tpg->tpg_group.cg_item);
1436 }
1437 
1438 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1439 {
1440 	target_undepend_item(&tpg->tpg_group.cg_item);
1441 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1442 }
1443 
1444 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1445 {
1446 	if (nacl->dynamic_node_acl)
1447 		return 0;
1448 	return target_depend_item(&nacl->acl_group.cg_item);
1449 }
1450 
1451 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1452 {
1453 	if (!nacl->dynamic_node_acl)
1454 		target_undepend_item(&nacl->acl_group.cg_item);
1455 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1456 }
1457 
1458 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1459 {
1460 	struct se_lun_acl *lun_acl;
1461 
1462 	/*
1463 	 * For nacl->dynamic_node_acl=1
1464 	 */
1465 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1466 				kref_read(&se_deve->pr_kref) != 0);
1467 	if (!lun_acl)
1468 		return 0;
1469 
1470 	return target_depend_item(&lun_acl->se_lun_group.cg_item);
1471 }
1472 
1473 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1474 {
1475 	struct se_lun_acl *lun_acl;
1476 
1477 	/*
1478 	 * For nacl->dynamic_node_acl=1
1479 	 */
1480 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1481 				kref_read(&se_deve->pr_kref) != 0);
1482 	if (!lun_acl) {
1483 		kref_put(&se_deve->pr_kref, target_pr_kref_release);
1484 		return;
1485 	}
1486 
1487 	target_undepend_item(&lun_acl->se_lun_group.cg_item);
1488 	kref_put(&se_deve->pr_kref, target_pr_kref_release);
1489 }
1490 
1491 static sense_reason_t
1492 core_scsi3_decode_spec_i_port(
1493 	struct se_cmd *cmd,
1494 	struct se_portal_group *tpg,
1495 	unsigned char *l_isid,
1496 	u64 sa_res_key,
1497 	int all_tg_pt,
1498 	int aptpl)
1499 {
1500 	struct se_device *dev = cmd->se_dev;
1501 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1502 	struct se_session *se_sess = cmd->se_sess;
1503 	struct se_node_acl *dest_node_acl = NULL;
1504 	struct se_dev_entry *dest_se_deve = NULL;
1505 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1506 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1507 	LIST_HEAD(tid_dest_list);
1508 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1509 	unsigned char *buf, *ptr, proto_ident;
1510 	const unsigned char *i_str = NULL;
1511 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1512 	sense_reason_t ret;
1513 	u32 tpdl, tid_len = 0;
1514 	u32 dest_rtpi = 0;
1515 
1516 	/*
1517 	 * Allocate a struct pr_transport_id_holder and setup the
1518 	 * local_node_acl pointer and add to struct list_head tid_dest_list
1519 	 * for add registration processing in the loop of tid_dest_list below.
1520 	 */
1521 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1522 	if (!tidh_new) {
1523 		pr_err("Unable to allocate tidh_new\n");
1524 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1525 	}
1526 	INIT_LIST_HEAD(&tidh_new->dest_list);
1527 	tidh_new->dest_tpg = tpg;
1528 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1529 
1530 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1531 				se_sess->se_node_acl, cmd->se_lun,
1532 				NULL, cmd->orig_fe_lun, l_isid,
1533 				sa_res_key, all_tg_pt, aptpl);
1534 	if (!local_pr_reg) {
1535 		kfree(tidh_new);
1536 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1537 	}
1538 	tidh_new->dest_pr_reg = local_pr_reg;
1539 	/*
1540 	 * The local I_T nexus does not hold any configfs dependances,
1541 	 * so we set tidh_new->dest_se_deve to NULL to prevent the
1542 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1543 	 */
1544 	tidh_new->dest_se_deve = NULL;
1545 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1546 
1547 	if (cmd->data_length < 28) {
1548 		pr_warn("SPC-PR: Received PR OUT parameter list"
1549 			" length too small: %u\n", cmd->data_length);
1550 		ret = TCM_INVALID_PARAMETER_LIST;
1551 		goto out;
1552 	}
1553 
1554 	buf = transport_kmap_data_sg(cmd);
1555 	if (!buf) {
1556 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1557 		goto out;
1558 	}
1559 
1560 	/*
1561 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1562 	 * first extract TransportID Parameter Data Length, and make sure
1563 	 * the value matches up to the SCSI expected data transfer length.
1564 	 */
1565 	tpdl = get_unaligned_be32(&buf[24]);
1566 
1567 	if ((tpdl + 28) != cmd->data_length) {
1568 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1569 			" does not equal CDB data_length: %u\n", tpdl,
1570 			cmd->data_length);
1571 		ret = TCM_INVALID_PARAMETER_LIST;
1572 		goto out_unmap;
1573 	}
1574 	/*
1575 	 * Start processing the received transport IDs using the
1576 	 * receiving I_T Nexus portal's fabric dependent methods to
1577 	 * obtain the SCSI Initiator Port/Device Identifiers.
1578 	 */
1579 	ptr = &buf[28];
1580 
1581 	while (tpdl > 0) {
1582 		struct se_lun *dest_lun, *tmp_lun;
1583 
1584 		proto_ident = (ptr[0] & 0x0f);
1585 		dest_tpg = NULL;
1586 
1587 		spin_lock(&dev->se_port_lock);
1588 		list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
1589 			tmp_tpg = tmp_lun->lun_tpg;
1590 
1591 			/*
1592 			 * Look for the matching proto_ident provided by
1593 			 * the received TransportID
1594 			 */
1595 			if (tmp_tpg->proto_id != proto_ident)
1596 				continue;
1597 			dest_rtpi = tmp_lun->lun_rtpi;
1598 
1599 			i_str = target_parse_pr_out_transport_id(tmp_tpg,
1600 					(const char *)ptr, &tid_len, &iport_ptr);
1601 			if (!i_str)
1602 				continue;
1603 
1604 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1605 			spin_unlock(&dev->se_port_lock);
1606 
1607 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1608 				pr_err(" core_scsi3_tpg_depend_item()"
1609 					" for tmp_tpg\n");
1610 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1611 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1612 				goto out_unmap;
1613 			}
1614 			/*
1615 			 * Locate the destination initiator ACL to be registered
1616 			 * from the decoded fabric module specific TransportID
1617 			 * at *i_str.
1618 			 */
1619 			mutex_lock(&tmp_tpg->acl_node_mutex);
1620 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1621 						tmp_tpg, i_str);
1622 			if (dest_node_acl)
1623 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1624 			mutex_unlock(&tmp_tpg->acl_node_mutex);
1625 
1626 			if (!dest_node_acl) {
1627 				core_scsi3_tpg_undepend_item(tmp_tpg);
1628 				spin_lock(&dev->se_port_lock);
1629 				continue;
1630 			}
1631 
1632 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1633 				pr_err("configfs_depend_item() failed"
1634 					" for dest_node_acl->acl_group\n");
1635 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1636 				core_scsi3_tpg_undepend_item(tmp_tpg);
1637 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1638 				goto out_unmap;
1639 			}
1640 
1641 			dest_tpg = tmp_tpg;
1642 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1643 				" %s Port RTPI: %hu\n",
1644 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1645 				dest_node_acl->initiatorname, dest_rtpi);
1646 
1647 			spin_lock(&dev->se_port_lock);
1648 			break;
1649 		}
1650 		spin_unlock(&dev->se_port_lock);
1651 
1652 		if (!dest_tpg) {
1653 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1654 					" dest_tpg\n");
1655 			ret = TCM_INVALID_PARAMETER_LIST;
1656 			goto out_unmap;
1657 		}
1658 
1659 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1660 			" tid_len: %d for %s + %s\n",
1661 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1662 			tpdl, tid_len, i_str, iport_ptr);
1663 
1664 		if (tid_len > tpdl) {
1665 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1666 				" %u for Transport ID: %s\n", tid_len, ptr);
1667 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1668 			core_scsi3_tpg_undepend_item(dest_tpg);
1669 			ret = TCM_INVALID_PARAMETER_LIST;
1670 			goto out_unmap;
1671 		}
1672 		/*
1673 		 * Locate the desintation struct se_dev_entry pointer for matching
1674 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1675 		 * Target Port.
1676 		 */
1677 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1678 					dest_rtpi);
1679 		if (!dest_se_deve) {
1680 			pr_err("Unable to locate %s dest_se_deve"
1681 				" from destination RTPI: %hu\n",
1682 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1683 				dest_rtpi);
1684 
1685 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1686 			core_scsi3_tpg_undepend_item(dest_tpg);
1687 			ret = TCM_INVALID_PARAMETER_LIST;
1688 			goto out_unmap;
1689 		}
1690 
1691 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1692 			pr_err("core_scsi3_lunacl_depend_item()"
1693 					" failed\n");
1694 			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
1695 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1696 			core_scsi3_tpg_undepend_item(dest_tpg);
1697 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1698 			goto out_unmap;
1699 		}
1700 
1701 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1702 			" dest_se_deve mapped_lun: %llu\n",
1703 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1704 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1705 
1706 		/*
1707 		 * Skip any TransportIDs that already have a registration for
1708 		 * this target port.
1709 		 */
1710 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1711 					iport_ptr);
1712 		if (pr_reg_e) {
1713 			core_scsi3_put_pr_reg(pr_reg_e);
1714 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1715 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1716 			core_scsi3_tpg_undepend_item(dest_tpg);
1717 			ptr += tid_len;
1718 			tpdl -= tid_len;
1719 			tid_len = 0;
1720 			continue;
1721 		}
1722 		/*
1723 		 * Allocate a struct pr_transport_id_holder and setup
1724 		 * the dest_node_acl and dest_se_deve pointers for the
1725 		 * loop below.
1726 		 */
1727 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1728 				GFP_KERNEL);
1729 		if (!tidh_new) {
1730 			pr_err("Unable to allocate tidh_new\n");
1731 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1732 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1733 			core_scsi3_tpg_undepend_item(dest_tpg);
1734 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1735 			goto out_unmap;
1736 		}
1737 		INIT_LIST_HEAD(&tidh_new->dest_list);
1738 		tidh_new->dest_tpg = dest_tpg;
1739 		tidh_new->dest_node_acl = dest_node_acl;
1740 		tidh_new->dest_se_deve = dest_se_deve;
1741 
1742 		/*
1743 		 * Allocate, but do NOT add the registration for the
1744 		 * TransportID referenced SCSI Initiator port.  This
1745 		 * done because of the following from spc4r17 in section
1746 		 * 6.14.3 wrt SPEC_I_PT:
1747 		 *
1748 		 * "If a registration fails for any initiator port (e.g., if th
1749 		 * logical unit does not have enough resources available to
1750 		 * hold the registration information), no registrations shall be
1751 		 * made, and the command shall be terminated with
1752 		 * CHECK CONDITION status."
1753 		 *
1754 		 * That means we call __core_scsi3_alloc_registration() here,
1755 		 * and then call __core_scsi3_add_registration() in the
1756 		 * 2nd loop which will never fail.
1757 		 */
1758 		dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
1759 				kref_read(&dest_se_deve->pr_kref) != 0);
1760 
1761 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1762 					dest_node_acl, dest_lun, dest_se_deve,
1763 					dest_se_deve->mapped_lun, iport_ptr,
1764 					sa_res_key, all_tg_pt, aptpl);
1765 		if (!dest_pr_reg) {
1766 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1767 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1768 			core_scsi3_tpg_undepend_item(dest_tpg);
1769 			kfree(tidh_new);
1770 			ret = TCM_INVALID_PARAMETER_LIST;
1771 			goto out_unmap;
1772 		}
1773 		tidh_new->dest_pr_reg = dest_pr_reg;
1774 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1775 
1776 		ptr += tid_len;
1777 		tpdl -= tid_len;
1778 		tid_len = 0;
1779 
1780 	}
1781 
1782 	transport_kunmap_data_sg(cmd);
1783 
1784 	/*
1785 	 * Go ahead and create a registrations from tid_dest_list for the
1786 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1787 	 * and dest_se_deve.
1788 	 *
1789 	 * The SA Reservation Key from the PROUT is set for the
1790 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1791 	 * means that the TransportID Initiator port will be
1792 	 * registered on all of the target ports in the SCSI target device
1793 	 * ALL_TG_PT=0 means the registration will only be for the
1794 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1795 	 * was received.
1796 	 */
1797 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1798 		dest_tpg = tidh->dest_tpg;
1799 		dest_node_acl = tidh->dest_node_acl;
1800 		dest_se_deve = tidh->dest_se_deve;
1801 		dest_pr_reg = tidh->dest_pr_reg;
1802 
1803 		list_del(&tidh->dest_list);
1804 		kfree(tidh);
1805 
1806 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1807 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1808 
1809 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1810 					dest_pr_reg, 0, 0);
1811 
1812 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1813 			" registered Transport ID for Node: %s%s Mapped LUN:"
1814 			" %llu\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1815 			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
1816 			dest_se_deve->mapped_lun : 0);
1817 
1818 		if (!dest_se_deve) {
1819 			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1820 				 target_pr_kref_release);
1821 			continue;
1822 		}
1823 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1824 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1825 		core_scsi3_tpg_undepend_item(dest_tpg);
1826 	}
1827 
1828 	return 0;
1829 out_unmap:
1830 	transport_kunmap_data_sg(cmd);
1831 out:
1832 	/*
1833 	 * For the failure case, release everything from tid_dest_list
1834 	 * including *dest_pr_reg and the configfs dependances..
1835 	 */
1836 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1837 		dest_tpg = tidh->dest_tpg;
1838 		dest_node_acl = tidh->dest_node_acl;
1839 		dest_se_deve = tidh->dest_se_deve;
1840 		dest_pr_reg = tidh->dest_pr_reg;
1841 
1842 		list_del(&tidh->dest_list);
1843 		kfree(tidh);
1844 		/*
1845 		 * Release any extra ALL_TG_PT=1 registrations for
1846 		 * the SPEC_I_PT=1 case.
1847 		 */
1848 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1849 				&dest_pr_reg->pr_reg_atp_list,
1850 				pr_reg_atp_mem_list) {
1851 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1852 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1853 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1854 		}
1855 
1856 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1857 
1858 		if (!dest_se_deve) {
1859 			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1860 				 target_pr_kref_release);
1861 			continue;
1862 		}
1863 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1864 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1865 		core_scsi3_tpg_undepend_item(dest_tpg);
1866 	}
1867 	return ret;
1868 }
1869 
1870 static int core_scsi3_update_aptpl_buf(
1871 	struct se_device *dev,
1872 	unsigned char *buf,
1873 	u32 pr_aptpl_buf_len)
1874 {
1875 	struct se_portal_group *tpg;
1876 	struct t10_pr_registration *pr_reg;
1877 	unsigned char tmp[512], isid_buf[32];
1878 	ssize_t len = 0;
1879 	int reg_count = 0;
1880 	int ret = 0;
1881 
1882 	spin_lock(&dev->dev_reservation_lock);
1883 	spin_lock(&dev->t10_pr.registration_lock);
1884 	/*
1885 	 * Walk the registration list..
1886 	 */
1887 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1888 			pr_reg_list) {
1889 
1890 		tmp[0] = '\0';
1891 		isid_buf[0] = '\0';
1892 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1893 		/*
1894 		 * Write out any ISID value to APTPL metadata that was included
1895 		 * in the original registration.
1896 		 */
1897 		if (pr_reg->isid_present_at_reg)
1898 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1899 					pr_reg->pr_reg_isid);
1900 		/*
1901 		 * Include special metadata if the pr_reg matches the
1902 		 * reservation holder.
1903 		 */
1904 		if (dev->dev_pr_res_holder == pr_reg) {
1905 			snprintf(tmp, 512, "PR_REG_START: %d"
1906 				"\ninitiator_fabric=%s\n"
1907 				"initiator_node=%s\n%s"
1908 				"sa_res_key=%llu\n"
1909 				"res_holder=1\nres_type=%02x\n"
1910 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1911 				"mapped_lun=%llu\n", reg_count,
1912 				tpg->se_tpg_tfo->get_fabric_name(),
1913 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1914 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1915 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1916 				pr_reg->pr_res_mapped_lun);
1917 		} else {
1918 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1919 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1920 				"sa_res_key=%llu\nres_holder=0\n"
1921 				"res_all_tg_pt=%d\nmapped_lun=%llu\n",
1922 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1923 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1924 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1925 				pr_reg->pr_res_mapped_lun);
1926 		}
1927 
1928 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1929 			pr_err("Unable to update renaming APTPL metadata,"
1930 			       " reallocating larger buffer\n");
1931 			ret = -EMSGSIZE;
1932 			goto out;
1933 		}
1934 		len += sprintf(buf+len, "%s", tmp);
1935 
1936 		/*
1937 		 * Include information about the associated SCSI target port.
1938 		 */
1939 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1940 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%llu\nPR_REG_END:"
1941 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1942 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1943 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1944 			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
1945 			reg_count);
1946 
1947 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1948 			pr_err("Unable to update renaming APTPL metadata,"
1949 			       " reallocating larger buffer\n");
1950 			ret = -EMSGSIZE;
1951 			goto out;
1952 		}
1953 		len += sprintf(buf+len, "%s", tmp);
1954 		reg_count++;
1955 	}
1956 
1957 	if (!reg_count)
1958 		len += sprintf(buf+len, "No Registrations or Reservations");
1959 
1960 out:
1961 	spin_unlock(&dev->t10_pr.registration_lock);
1962 	spin_unlock(&dev->dev_reservation_lock);
1963 
1964 	return ret;
1965 }
1966 
1967 static int __core_scsi3_write_aptpl_to_file(
1968 	struct se_device *dev,
1969 	unsigned char *buf)
1970 {
1971 	struct t10_wwn *wwn = &dev->t10_wwn;
1972 	struct file *file;
1973 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1974 	char path[512];
1975 	u32 pr_aptpl_buf_len;
1976 	int ret;
1977 
1978 	memset(path, 0, 512);
1979 
1980 	if (strlen(&wwn->unit_serial[0]) >= 512) {
1981 		pr_err("WWN value for struct se_device does not fit"
1982 			" into path buffer\n");
1983 		return -EMSGSIZE;
1984 	}
1985 
1986 	snprintf(path, 512, "%s/pr/aptpl_%s", db_root, &wwn->unit_serial[0]);
1987 	file = filp_open(path, flags, 0600);
1988 	if (IS_ERR(file)) {
1989 		pr_err("filp_open(%s) for APTPL metadata"
1990 			" failed\n", path);
1991 		return PTR_ERR(file);
1992 	}
1993 
1994 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1995 
1996 	ret = kernel_write(file, buf, pr_aptpl_buf_len, 0);
1997 
1998 	if (ret < 0)
1999 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2000 	fput(file);
2001 
2002 	return (ret < 0) ? -EIO : 0;
2003 }
2004 
2005 /*
2006  * Clear the APTPL metadata if APTPL has been disabled, otherwise
2007  * write out the updated metadata to struct file for this SCSI device.
2008  */
2009 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
2010 {
2011 	unsigned char *buf;
2012 	int rc, len = PR_APTPL_BUF_LEN;
2013 
2014 	if (!aptpl) {
2015 		char *null_buf = "No Registrations or Reservations\n";
2016 
2017 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
2018 		dev->t10_pr.pr_aptpl_active = 0;
2019 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
2020 
2021 		if (rc)
2022 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2023 
2024 		return 0;
2025 	}
2026 retry:
2027 	buf = vzalloc(len);
2028 	if (!buf)
2029 		return TCM_OUT_OF_RESOURCES;
2030 
2031 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
2032 	if (rc < 0) {
2033 		vfree(buf);
2034 		len *= 2;
2035 		goto retry;
2036 	}
2037 
2038 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2039 	if (rc != 0) {
2040 		pr_err("SPC-3 PR: Could not update APTPL\n");
2041 		vfree(buf);
2042 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2043 	}
2044 	dev->t10_pr.pr_aptpl_active = 1;
2045 	vfree(buf);
2046 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2047 	return 0;
2048 }
2049 
2050 static sense_reason_t
2051 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2052 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2053 {
2054 	struct se_session *se_sess = cmd->se_sess;
2055 	struct se_device *dev = cmd->se_dev;
2056 	struct se_lun *se_lun = cmd->se_lun;
2057 	struct se_portal_group *se_tpg;
2058 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2059 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2060 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2061 	sense_reason_t ret = TCM_NO_SENSE;
2062 	int pr_holder = 0, type;
2063 
2064 	if (!se_sess || !se_lun) {
2065 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2066 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2067 	}
2068 	se_tpg = se_sess->se_tpg;
2069 
2070 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2071 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2072 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2073 				PR_REG_ISID_LEN);
2074 		isid_ptr = &isid_buf[0];
2075 	}
2076 	/*
2077 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2078 	 */
2079 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2080 	if (!pr_reg) {
2081 		if (res_key) {
2082 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2083 				" for SA REGISTER, returning CONFLICT\n");
2084 			return TCM_RESERVATION_CONFLICT;
2085 		}
2086 		/*
2087 		 * Do nothing but return GOOD status.
2088 		 */
2089 		if (!sa_res_key)
2090 			return 0;
2091 
2092 		if (!spec_i_pt) {
2093 			/*
2094 			 * Perform the Service Action REGISTER on the Initiator
2095 			 * Port Endpoint that the PRO was received from on the
2096 			 * Logical Unit of the SCSI device server.
2097 			 */
2098 			if (core_scsi3_alloc_registration(cmd->se_dev,
2099 					se_sess->se_node_acl, cmd->se_lun,
2100 					NULL, cmd->orig_fe_lun, isid_ptr,
2101 					sa_res_key, all_tg_pt, aptpl,
2102 					register_type, 0)) {
2103 				pr_err("Unable to allocate"
2104 					" struct t10_pr_registration\n");
2105 				return TCM_INVALID_PARAMETER_LIST;
2106 			}
2107 		} else {
2108 			/*
2109 			 * Register both the Initiator port that received
2110 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2111 			 * TransportID from Parameter list and loop through
2112 			 * fabric dependent parameter list while calling
2113 			 * logic from of core_scsi3_alloc_registration() for
2114 			 * each TransportID provided SCSI Initiator Port/Device
2115 			 */
2116 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2117 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2118 			if (ret != 0)
2119 				return ret;
2120 		}
2121 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2122 	}
2123 
2124 	/* ok, existing registration */
2125 
2126 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2127 		pr_err("SPC-3 PR REGISTER: Received"
2128 		       " res_key: 0x%016Lx does not match"
2129 		       " existing SA REGISTER res_key:"
2130 		       " 0x%016Lx\n", res_key,
2131 		       pr_reg->pr_res_key);
2132 		ret = TCM_RESERVATION_CONFLICT;
2133 		goto out;
2134 	}
2135 
2136 	if (spec_i_pt) {
2137 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2138 			" set on a registered nexus\n");
2139 		ret = TCM_INVALID_PARAMETER_LIST;
2140 		goto out;
2141 	}
2142 
2143 	/*
2144 	 * An existing ALL_TG_PT=1 registration being released
2145 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2146 	 */
2147 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2148 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2149 			" registration exists, but ALL_TG_PT=1 bit not"
2150 			" present in received PROUT\n");
2151 		ret = TCM_INVALID_CDB_FIELD;
2152 		goto out;
2153 	}
2154 
2155 	/*
2156 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2157 	 */
2158 	if (sa_res_key) {
2159 		/*
2160 		 * Increment PRgeneration counter for struct se_device"
2161 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2162 		 * READ_KEYS service action.
2163 		 */
2164 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2165 		pr_reg->pr_res_key = sa_res_key;
2166 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2167 			 " Key for %s to: 0x%016Lx PRgeneration:"
2168 			 " 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2169 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2170 			 pr_reg->pr_reg_nacl->initiatorname,
2171 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2172 
2173 	} else {
2174 		/*
2175 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2176 		 */
2177 		type = pr_reg->pr_res_type;
2178 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2179 							      pr_reg);
2180 		if (pr_holder < 0) {
2181 			ret = TCM_RESERVATION_CONFLICT;
2182 			goto out;
2183 		}
2184 
2185 		spin_lock(&pr_tmpl->registration_lock);
2186 		/*
2187 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2188 		 * and matching pr_res_key.
2189 		 */
2190 		if (pr_reg->pr_reg_all_tg_pt) {
2191 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2192 					&pr_tmpl->registration_list,
2193 					pr_reg_list) {
2194 
2195 				if (!pr_reg_p->pr_reg_all_tg_pt)
2196 					continue;
2197 				if (pr_reg_p->pr_res_key != res_key)
2198 					continue;
2199 				if (pr_reg == pr_reg_p)
2200 					continue;
2201 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2202 					   pr_reg_p->pr_reg_nacl->initiatorname))
2203 					continue;
2204 
2205 				__core_scsi3_free_registration(dev,
2206 						pr_reg_p, NULL, 0);
2207 			}
2208 		}
2209 
2210 		/*
2211 		 * Release the calling I_T Nexus registration now..
2212 		 */
2213 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2214 		pr_reg = NULL;
2215 
2216 		/*
2217 		 * From spc4r17, section 5.7.11.3 Unregistering
2218 		 *
2219 		 * If the persistent reservation is a registrants only
2220 		 * type, the device server shall establish a unit
2221 		 * attention condition for the initiator port associated
2222 		 * with every registered I_T nexus except for the I_T
2223 		 * nexus on which the PERSISTENT RESERVE OUT command was
2224 		 * received, with the additional sense code set to
2225 		 * RESERVATIONS RELEASED.
2226 		 */
2227 		if (pr_holder &&
2228 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2229 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2230 			list_for_each_entry(pr_reg_p,
2231 					&pr_tmpl->registration_list,
2232 					pr_reg_list) {
2233 
2234 				target_ua_allocate_lun(
2235 					pr_reg_p->pr_reg_nacl,
2236 					pr_reg_p->pr_res_mapped_lun,
2237 					0x2A,
2238 					ASCQ_2AH_RESERVATIONS_RELEASED);
2239 			}
2240 		}
2241 
2242 		spin_unlock(&pr_tmpl->registration_lock);
2243 	}
2244 
2245 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2246 
2247 out:
2248 	if (pr_reg)
2249 		core_scsi3_put_pr_reg(pr_reg);
2250 	return ret;
2251 }
2252 
2253 unsigned char *core_scsi3_pr_dump_type(int type)
2254 {
2255 	switch (type) {
2256 	case PR_TYPE_WRITE_EXCLUSIVE:
2257 		return "Write Exclusive Access";
2258 	case PR_TYPE_EXCLUSIVE_ACCESS:
2259 		return "Exclusive Access";
2260 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2261 		return "Write Exclusive Access, Registrants Only";
2262 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2263 		return "Exclusive Access, Registrants Only";
2264 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2265 		return "Write Exclusive Access, All Registrants";
2266 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2267 		return "Exclusive Access, All Registrants";
2268 	default:
2269 		break;
2270 	}
2271 
2272 	return "Unknown SPC-3 PR Type";
2273 }
2274 
2275 static sense_reason_t
2276 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2277 {
2278 	struct se_device *dev = cmd->se_dev;
2279 	struct se_session *se_sess = cmd->se_sess;
2280 	struct se_lun *se_lun = cmd->se_lun;
2281 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2282 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2283 	char i_buf[PR_REG_ISID_ID_LEN];
2284 	sense_reason_t ret;
2285 
2286 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2287 
2288 	if (!se_sess || !se_lun) {
2289 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2290 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2291 	}
2292 	/*
2293 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2294 	 */
2295 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2296 				se_sess);
2297 	if (!pr_reg) {
2298 		pr_err("SPC-3 PR: Unable to locate"
2299 			" PR_REGISTERED *pr_reg for RESERVE\n");
2300 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2301 	}
2302 	/*
2303 	 * From spc4r17 Section 5.7.9: Reserving:
2304 	 *
2305 	 * An application client creates a persistent reservation by issuing
2306 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2307 	 * a registered I_T nexus with the following parameters:
2308 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2309 	 * 	 registered with the logical unit for the I_T nexus; and
2310 	 */
2311 	if (res_key != pr_reg->pr_res_key) {
2312 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2313 			" does not match existing SA REGISTER res_key:"
2314 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2315 		ret = TCM_RESERVATION_CONFLICT;
2316 		goto out_put_pr_reg;
2317 	}
2318 	/*
2319 	 * From spc4r17 Section 5.7.9: Reserving:
2320 	 *
2321 	 * From above:
2322 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2323 	 *     being created.
2324 	 *
2325 	 * Only one persistent reservation is allowed at a time per logical unit
2326 	 * and that persistent reservation has a scope of LU_SCOPE.
2327 	 */
2328 	if (scope != PR_SCOPE_LU_SCOPE) {
2329 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2330 		ret = TCM_INVALID_PARAMETER_LIST;
2331 		goto out_put_pr_reg;
2332 	}
2333 	/*
2334 	 * See if we have an existing PR reservation holder pointer at
2335 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2336 	 * *pr_res_holder.
2337 	 */
2338 	spin_lock(&dev->dev_reservation_lock);
2339 	pr_res_holder = dev->dev_pr_res_holder;
2340 	if (pr_res_holder) {
2341 		/*
2342 		 * From spc4r17 Section 5.7.9: Reserving:
2343 		 *
2344 		 * If the device server receives a PERSISTENT RESERVE OUT
2345 		 * command from an I_T nexus other than a persistent reservation
2346 		 * holder (see 5.7.10) that attempts to create a persistent
2347 		 * reservation when a persistent reservation already exists for
2348 		 * the logical unit, then the command shall be completed with
2349 		 * RESERVATION CONFLICT status.
2350 		 */
2351 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2352 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2353 			pr_err("SPC-3 PR: Attempted RESERVE from"
2354 				" [%s]: %s while reservation already held by"
2355 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2356 				cmd->se_tfo->get_fabric_name(),
2357 				se_sess->se_node_acl->initiatorname,
2358 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2359 				pr_res_holder->pr_reg_nacl->initiatorname);
2360 
2361 			spin_unlock(&dev->dev_reservation_lock);
2362 			ret = TCM_RESERVATION_CONFLICT;
2363 			goto out_put_pr_reg;
2364 		}
2365 		/*
2366 		 * From spc4r17 Section 5.7.9: Reserving:
2367 		 *
2368 		 * If a persistent reservation holder attempts to modify the
2369 		 * type or scope of an existing persistent reservation, the
2370 		 * command shall be completed with RESERVATION CONFLICT status.
2371 		 */
2372 		if ((pr_res_holder->pr_res_type != type) ||
2373 		    (pr_res_holder->pr_res_scope != scope)) {
2374 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2375 			pr_err("SPC-3 PR: Attempted RESERVE from"
2376 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2377 				" while reservation already held by [%s]: %s,"
2378 				" returning RESERVATION_CONFLICT\n",
2379 				cmd->se_tfo->get_fabric_name(),
2380 				se_sess->se_node_acl->initiatorname,
2381 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2382 				pr_res_holder->pr_reg_nacl->initiatorname);
2383 
2384 			spin_unlock(&dev->dev_reservation_lock);
2385 			ret = TCM_RESERVATION_CONFLICT;
2386 			goto out_put_pr_reg;
2387 		}
2388 		/*
2389 		 * From spc4r17 Section 5.7.9: Reserving:
2390 		 *
2391 		 * If the device server receives a PERSISTENT RESERVE OUT
2392 		 * command with RESERVE service action where the TYPE field and
2393 		 * the SCOPE field contain the same values as the existing type
2394 		 * and scope from a persistent reservation holder, it shall not
2395 		 * make any change to the existing persistent reservation and
2396 		 * shall completethe command with GOOD status.
2397 		 */
2398 		spin_unlock(&dev->dev_reservation_lock);
2399 		ret = 0;
2400 		goto out_put_pr_reg;
2401 	}
2402 	/*
2403 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2404 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2405 	 */
2406 	pr_reg->pr_res_scope = scope;
2407 	pr_reg->pr_res_type = type;
2408 	pr_reg->pr_res_holder = 1;
2409 	dev->dev_pr_res_holder = pr_reg;
2410 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2411 
2412 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2413 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2414 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2415 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2416 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2417 			cmd->se_tfo->get_fabric_name(),
2418 			se_sess->se_node_acl->initiatorname,
2419 			i_buf);
2420 	spin_unlock(&dev->dev_reservation_lock);
2421 
2422 	if (pr_tmpl->pr_aptpl_active)
2423 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2424 
2425 	ret = 0;
2426 out_put_pr_reg:
2427 	core_scsi3_put_pr_reg(pr_reg);
2428 	return ret;
2429 }
2430 
2431 static sense_reason_t
2432 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2433 		u64 res_key)
2434 {
2435 	switch (type) {
2436 	case PR_TYPE_WRITE_EXCLUSIVE:
2437 	case PR_TYPE_EXCLUSIVE_ACCESS:
2438 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2439 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2440 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2441 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2442 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2443 	default:
2444 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2445 			" 0x%02x\n", type);
2446 		return TCM_INVALID_CDB_FIELD;
2447 	}
2448 }
2449 
2450 /*
2451  * Called with struct se_device->dev_reservation_lock held.
2452  */
2453 static void __core_scsi3_complete_pro_release(
2454 	struct se_device *dev,
2455 	struct se_node_acl *se_nacl,
2456 	struct t10_pr_registration *pr_reg,
2457 	int explicit,
2458 	int unreg)
2459 {
2460 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2461 	char i_buf[PR_REG_ISID_ID_LEN];
2462 	int pr_res_type = 0, pr_res_scope = 0;
2463 
2464 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2465 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2466 	/*
2467 	 * Go ahead and release the current PR reservation holder.
2468 	 * If an All Registrants reservation is currently active and
2469 	 * a unregister operation is requested, replace the current
2470 	 * dev_pr_res_holder with another active registration.
2471 	 */
2472 	if (dev->dev_pr_res_holder) {
2473 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2474 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2475 		dev->dev_pr_res_holder->pr_res_type = 0;
2476 		dev->dev_pr_res_holder->pr_res_scope = 0;
2477 		dev->dev_pr_res_holder->pr_res_holder = 0;
2478 		dev->dev_pr_res_holder = NULL;
2479 	}
2480 	if (!unreg)
2481 		goto out;
2482 
2483 	spin_lock(&dev->t10_pr.registration_lock);
2484 	list_del_init(&pr_reg->pr_reg_list);
2485 	/*
2486 	 * If the I_T nexus is a reservation holder, the persistent reservation
2487 	 * is of an all registrants type, and the I_T nexus is the last remaining
2488 	 * registered I_T nexus, then the device server shall also release the
2489 	 * persistent reservation.
2490 	 */
2491 	if (!list_empty(&dev->t10_pr.registration_list) &&
2492 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2493 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2494 		dev->dev_pr_res_holder =
2495 			list_entry(dev->t10_pr.registration_list.next,
2496 				   struct t10_pr_registration, pr_reg_list);
2497 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2498 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2499 		dev->dev_pr_res_holder->pr_res_holder = 1;
2500 	}
2501 	spin_unlock(&dev->t10_pr.registration_lock);
2502 out:
2503 	if (!dev->dev_pr_res_holder) {
2504 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2505 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2506 			tfo->get_fabric_name(), (explicit) ? "explicit" :
2507 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2508 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2509 	}
2510 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2511 		tfo->get_fabric_name(), se_nacl->initiatorname,
2512 		i_buf);
2513 	/*
2514 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2515 	 */
2516 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2517 }
2518 
2519 static sense_reason_t
2520 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2521 		u64 res_key)
2522 {
2523 	struct se_device *dev = cmd->se_dev;
2524 	struct se_session *se_sess = cmd->se_sess;
2525 	struct se_lun *se_lun = cmd->se_lun;
2526 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2527 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2528 	sense_reason_t ret = 0;
2529 
2530 	if (!se_sess || !se_lun) {
2531 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2532 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2533 	}
2534 	/*
2535 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2536 	 */
2537 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2538 	if (!pr_reg) {
2539 		pr_err("SPC-3 PR: Unable to locate"
2540 			" PR_REGISTERED *pr_reg for RELEASE\n");
2541 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2542 	}
2543 	/*
2544 	 * From spc4r17 Section 5.7.11.2 Releasing:
2545 	 *
2546 	 * If there is no persistent reservation or in response to a persistent
2547 	 * reservation release request from a registered I_T nexus that is not a
2548 	 * persistent reservation holder (see 5.7.10), the device server shall
2549 	 * do the following:
2550 	 *
2551 	 *     a) Not release the persistent reservation, if any;
2552 	 *     b) Not remove any registrations; and
2553 	 *     c) Complete the command with GOOD status.
2554 	 */
2555 	spin_lock(&dev->dev_reservation_lock);
2556 	pr_res_holder = dev->dev_pr_res_holder;
2557 	if (!pr_res_holder) {
2558 		/*
2559 		 * No persistent reservation, return GOOD status.
2560 		 */
2561 		spin_unlock(&dev->dev_reservation_lock);
2562 		goto out_put_pr_reg;
2563 	}
2564 
2565 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2566 		/*
2567 		 * Release request from a registered I_T nexus that is not a
2568 		 * persistent reservation holder. return GOOD status.
2569 		 */
2570 		spin_unlock(&dev->dev_reservation_lock);
2571 		goto out_put_pr_reg;
2572 	}
2573 
2574 	/*
2575 	 * From spc4r17 Section 5.7.11.2 Releasing:
2576 	 *
2577 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2578 	 * release a persistent reservation.
2579 	 *
2580 	 * An application client releases the persistent reservation by issuing
2581 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2582 	 * an I_T nexus that is a persistent reservation holder with the
2583 	 * following parameters:
2584 	 *
2585 	 *     a) RESERVATION KEY field set to the value of the reservation key
2586 	 *	  that is registered with the logical unit for the I_T nexus;
2587 	 */
2588 	if (res_key != pr_reg->pr_res_key) {
2589 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2590 			" does not match existing SA REGISTER res_key:"
2591 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2592 		spin_unlock(&dev->dev_reservation_lock);
2593 		ret = TCM_RESERVATION_CONFLICT;
2594 		goto out_put_pr_reg;
2595 	}
2596 	/*
2597 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2598 	 *
2599 	 * b) TYPE field and SCOPE field set to match the persistent
2600 	 *    reservation being released.
2601 	 */
2602 	if ((pr_res_holder->pr_res_type != type) ||
2603 	    (pr_res_holder->pr_res_scope != scope)) {
2604 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2605 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2606 			" reservation from [%s]: %s with different TYPE "
2607 			"and/or SCOPE  while reservation already held by"
2608 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2609 			cmd->se_tfo->get_fabric_name(),
2610 			se_sess->se_node_acl->initiatorname,
2611 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2612 			pr_res_holder->pr_reg_nacl->initiatorname);
2613 
2614 		spin_unlock(&dev->dev_reservation_lock);
2615 		ret = TCM_RESERVATION_CONFLICT;
2616 		goto out_put_pr_reg;
2617 	}
2618 	/*
2619 	 * In response to a persistent reservation release request from the
2620 	 * persistent reservation holder the device server shall perform a
2621 	 * release by doing the following as an uninterrupted series of actions:
2622 	 * a) Release the persistent reservation;
2623 	 * b) Not remove any registration(s);
2624 	 * c) If the released persistent reservation is a registrants only type
2625 	 * or all registrants type persistent reservation,
2626 	 *    the device server shall establish a unit attention condition for
2627 	 *    the initiator port associated with every regis-
2628 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2629 	 *    RESERVE OUT command with RELEASE service action was received,
2630 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2631 	 * d) If the persistent reservation is of any other type, the device
2632 	 *    server shall not establish a unit attention condition.
2633 	 */
2634 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2635 					  pr_reg, 1, 0);
2636 
2637 	spin_unlock(&dev->dev_reservation_lock);
2638 
2639 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2640 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2641 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2642 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2643 		/*
2644 		 * If no UNIT ATTENTION conditions will be established for
2645 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2646 		 * go ahead and check for APTPL=1 update+write below
2647 		 */
2648 		goto write_aptpl;
2649 	}
2650 
2651 	spin_lock(&pr_tmpl->registration_lock);
2652 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2653 			pr_reg_list) {
2654 		/*
2655 		 * Do not establish a UNIT ATTENTION condition
2656 		 * for the calling I_T Nexus
2657 		 */
2658 		if (pr_reg_p == pr_reg)
2659 			continue;
2660 
2661 		target_ua_allocate_lun(pr_reg_p->pr_reg_nacl,
2662 				pr_reg_p->pr_res_mapped_lun,
2663 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2664 	}
2665 	spin_unlock(&pr_tmpl->registration_lock);
2666 
2667 write_aptpl:
2668 	if (pr_tmpl->pr_aptpl_active)
2669 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2670 
2671 out_put_pr_reg:
2672 	core_scsi3_put_pr_reg(pr_reg);
2673 	return ret;
2674 }
2675 
2676 static sense_reason_t
2677 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2678 {
2679 	struct se_device *dev = cmd->se_dev;
2680 	struct se_node_acl *pr_reg_nacl;
2681 	struct se_session *se_sess = cmd->se_sess;
2682 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2683 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2684 	u64 pr_res_mapped_lun = 0;
2685 	int calling_it_nexus = 0;
2686 	/*
2687 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2688 	 */
2689 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2690 			se_sess->se_node_acl, se_sess);
2691 	if (!pr_reg_n) {
2692 		pr_err("SPC-3 PR: Unable to locate"
2693 			" PR_REGISTERED *pr_reg for CLEAR\n");
2694 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2695 	}
2696 	/*
2697 	 * From spc4r17 section 5.7.11.6, Clearing:
2698 	 *
2699 	 * Any application client may release the persistent reservation and
2700 	 * remove all registrations from a device server by issuing a
2701 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2702 	 * registered I_T nexus with the following parameter:
2703 	 *
2704 	 *	a) RESERVATION KEY field set to the value of the reservation key
2705 	 * 	   that is registered with the logical unit for the I_T nexus.
2706 	 */
2707 	if (res_key != pr_reg_n->pr_res_key) {
2708 		pr_err("SPC-3 PR REGISTER: Received"
2709 			" res_key: 0x%016Lx does not match"
2710 			" existing SA REGISTER res_key:"
2711 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2712 		core_scsi3_put_pr_reg(pr_reg_n);
2713 		return TCM_RESERVATION_CONFLICT;
2714 	}
2715 	/*
2716 	 * a) Release the persistent reservation, if any;
2717 	 */
2718 	spin_lock(&dev->dev_reservation_lock);
2719 	pr_res_holder = dev->dev_pr_res_holder;
2720 	if (pr_res_holder) {
2721 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2722 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2723 						  pr_res_holder, 0, 0);
2724 	}
2725 	spin_unlock(&dev->dev_reservation_lock);
2726 	/*
2727 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2728 	 */
2729 	spin_lock(&pr_tmpl->registration_lock);
2730 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2731 			&pr_tmpl->registration_list, pr_reg_list) {
2732 
2733 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2734 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2735 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2736 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2737 					calling_it_nexus);
2738 		/*
2739 		 * e) Establish a unit attention condition for the initiator
2740 		 *    port associated with every registered I_T nexus other
2741 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2742 		 *    command with CLEAR service action was received, with the
2743 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2744 		 */
2745 		if (!calling_it_nexus)
2746 			target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun,
2747 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2748 	}
2749 	spin_unlock(&pr_tmpl->registration_lock);
2750 
2751 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2752 		cmd->se_tfo->get_fabric_name());
2753 
2754 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2755 
2756 	core_scsi3_pr_generation(dev);
2757 	return 0;
2758 }
2759 
2760 /*
2761  * Called with struct se_device->dev_reservation_lock held.
2762  */
2763 static void __core_scsi3_complete_pro_preempt(
2764 	struct se_device *dev,
2765 	struct t10_pr_registration *pr_reg,
2766 	struct list_head *preempt_and_abort_list,
2767 	int type,
2768 	int scope,
2769 	enum preempt_type preempt_type)
2770 {
2771 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2772 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2773 	char i_buf[PR_REG_ISID_ID_LEN];
2774 
2775 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2776 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2777 	/*
2778 	 * Do an implicit RELEASE of the existing reservation.
2779 	 */
2780 	if (dev->dev_pr_res_holder)
2781 		__core_scsi3_complete_pro_release(dev, nacl,
2782 						  dev->dev_pr_res_holder, 0, 0);
2783 
2784 	dev->dev_pr_res_holder = pr_reg;
2785 	pr_reg->pr_res_holder = 1;
2786 	pr_reg->pr_res_type = type;
2787 	pr_reg->pr_res_scope = scope;
2788 
2789 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2790 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2791 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2792 		core_scsi3_pr_dump_type(type),
2793 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2794 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2795 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2796 		nacl->initiatorname, i_buf);
2797 	/*
2798 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2799 	 * struct t10_pr_registration to the list that will be compared
2800 	 * against received CDBs..
2801 	 */
2802 	if (preempt_and_abort_list)
2803 		list_add_tail(&pr_reg->pr_reg_abort_list,
2804 				preempt_and_abort_list);
2805 }
2806 
2807 static void core_scsi3_release_preempt_and_abort(
2808 	struct list_head *preempt_and_abort_list,
2809 	struct t10_pr_registration *pr_reg_holder)
2810 {
2811 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2812 
2813 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2814 				pr_reg_abort_list) {
2815 
2816 		list_del(&pr_reg->pr_reg_abort_list);
2817 		if (pr_reg_holder == pr_reg)
2818 			continue;
2819 		if (pr_reg->pr_res_holder) {
2820 			pr_warn("pr_reg->pr_res_holder still set\n");
2821 			continue;
2822 		}
2823 
2824 		pr_reg->pr_reg_deve = NULL;
2825 		pr_reg->pr_reg_nacl = NULL;
2826 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2827 	}
2828 }
2829 
2830 static sense_reason_t
2831 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2832 		u64 sa_res_key, enum preempt_type preempt_type)
2833 {
2834 	struct se_device *dev = cmd->se_dev;
2835 	struct se_node_acl *pr_reg_nacl;
2836 	struct se_session *se_sess = cmd->se_sess;
2837 	LIST_HEAD(preempt_and_abort_list);
2838 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2839 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2840 	u64 pr_res_mapped_lun = 0;
2841 	int all_reg = 0, calling_it_nexus = 0;
2842 	bool sa_res_key_unmatched = sa_res_key != 0;
2843 	int prh_type = 0, prh_scope = 0;
2844 
2845 	if (!se_sess)
2846 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2847 
2848 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2849 				se_sess);
2850 	if (!pr_reg_n) {
2851 		pr_err("SPC-3 PR: Unable to locate"
2852 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2853 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2854 		return TCM_RESERVATION_CONFLICT;
2855 	}
2856 	if (pr_reg_n->pr_res_key != res_key) {
2857 		core_scsi3_put_pr_reg(pr_reg_n);
2858 		return TCM_RESERVATION_CONFLICT;
2859 	}
2860 	if (scope != PR_SCOPE_LU_SCOPE) {
2861 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2862 		core_scsi3_put_pr_reg(pr_reg_n);
2863 		return TCM_INVALID_PARAMETER_LIST;
2864 	}
2865 
2866 	spin_lock(&dev->dev_reservation_lock);
2867 	pr_res_holder = dev->dev_pr_res_holder;
2868 	if (pr_res_holder &&
2869 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2870 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2871 		all_reg = 1;
2872 
2873 	if (!all_reg && !sa_res_key) {
2874 		spin_unlock(&dev->dev_reservation_lock);
2875 		core_scsi3_put_pr_reg(pr_reg_n);
2876 		return TCM_INVALID_PARAMETER_LIST;
2877 	}
2878 	/*
2879 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2880 	 *
2881 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2882 	 * persistent reservation holder or there is no persistent reservation
2883 	 * holder (i.e., there is no persistent reservation), then the device
2884 	 * server shall perform a preempt by doing the following in an
2885 	 * uninterrupted series of actions. (See below..)
2886 	 */
2887 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2888 		/*
2889 		 * No existing or SA Reservation Key matching reservations..
2890 		 *
2891 		 * PROUT SA PREEMPT with All Registrant type reservations are
2892 		 * allowed to be processed without a matching SA Reservation Key
2893 		 */
2894 		spin_lock(&pr_tmpl->registration_lock);
2895 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2896 				&pr_tmpl->registration_list, pr_reg_list) {
2897 			/*
2898 			 * Removing of registrations in non all registrants
2899 			 * type reservations without a matching SA reservation
2900 			 * key.
2901 			 *
2902 			 * a) Remove the registrations for all I_T nexuses
2903 			 *    specified by the SERVICE ACTION RESERVATION KEY
2904 			 *    field;
2905 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2906 			 * c) Process tasks as defined in 5.7.1; and
2907 			 * d) Establish a unit attention condition for the
2908 			 *    initiator port associated with every I_T nexus
2909 			 *    that lost its registration other than the I_T
2910 			 *    nexus on which the PERSISTENT RESERVE OUT command
2911 			 *    was received, with the additional sense code set
2912 			 *    to REGISTRATIONS PREEMPTED.
2913 			 */
2914 			if (!all_reg) {
2915 				if (pr_reg->pr_res_key != sa_res_key)
2916 					continue;
2917 				sa_res_key_unmatched = false;
2918 
2919 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2920 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2921 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2922 				__core_scsi3_free_registration(dev, pr_reg,
2923 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2924 						NULL, calling_it_nexus);
2925 			} else {
2926 				/*
2927 				 * Case for any existing all registrants type
2928 				 * reservation, follow logic in spc4r17 section
2929 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2930 				 *
2931 				 * For a ZERO SA Reservation key, release
2932 				 * all other registrations and do an implicit
2933 				 * release of active persistent reservation.
2934 				 *
2935 				 * For a non-ZERO SA Reservation key, only
2936 				 * release the matching reservation key from
2937 				 * registrations.
2938 				 */
2939 				if ((sa_res_key) &&
2940 				     (pr_reg->pr_res_key != sa_res_key))
2941 					continue;
2942 				sa_res_key_unmatched = false;
2943 
2944 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2945 				if (calling_it_nexus)
2946 					continue;
2947 
2948 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2949 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2950 				__core_scsi3_free_registration(dev, pr_reg,
2951 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2952 						NULL, 0);
2953 			}
2954 			if (!calling_it_nexus)
2955 				target_ua_allocate_lun(pr_reg_nacl,
2956 					pr_res_mapped_lun, 0x2A,
2957 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2958 		}
2959 		spin_unlock(&pr_tmpl->registration_lock);
2960 		/*
2961 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2962 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2963 		 * RESERVATION KEY field to a value that does not match any
2964 		 * registered reservation key, then the device server shall
2965 		 * complete the command with RESERVATION CONFLICT status.
2966 		 */
2967 		if (sa_res_key_unmatched) {
2968 			spin_unlock(&dev->dev_reservation_lock);
2969 			core_scsi3_put_pr_reg(pr_reg_n);
2970 			return TCM_RESERVATION_CONFLICT;
2971 		}
2972 		/*
2973 		 * For an existing all registrants type reservation
2974 		 * with a zero SA rservation key, preempt the existing
2975 		 * reservation with the new PR type and scope.
2976 		 */
2977 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2978 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2979 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2980 				type, scope, preempt_type);
2981 
2982 			if (preempt_type == PREEMPT_AND_ABORT)
2983 				core_scsi3_release_preempt_and_abort(
2984 					&preempt_and_abort_list, pr_reg_n);
2985 		}
2986 		spin_unlock(&dev->dev_reservation_lock);
2987 
2988 		if (pr_tmpl->pr_aptpl_active)
2989 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2990 
2991 		core_scsi3_put_pr_reg(pr_reg_n);
2992 		core_scsi3_pr_generation(cmd->se_dev);
2993 		return 0;
2994 	}
2995 	/*
2996 	 * The PREEMPTing SA reservation key matches that of the
2997 	 * existing persistent reservation, first, we check if
2998 	 * we are preempting our own reservation.
2999 	 * From spc4r17, section 5.7.11.4.3 Preempting
3000 	 * persistent reservations and registration handling
3001 	 *
3002 	 * If an all registrants persistent reservation is not
3003 	 * present, it is not an error for the persistent
3004 	 * reservation holder to preempt itself (i.e., a
3005 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3006 	 * or a PREEMPT AND ABORT service action with the
3007 	 * SERVICE ACTION RESERVATION KEY value equal to the
3008 	 * persistent reservation holder's reservation key that
3009 	 * is received from the persistent reservation holder).
3010 	 * In that case, the device server shall establish the
3011 	 * new persistent reservation and maintain the
3012 	 * registration.
3013 	 */
3014 	prh_type = pr_res_holder->pr_res_type;
3015 	prh_scope = pr_res_holder->pr_res_scope;
3016 	/*
3017 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3018 	 * persistent reservation holder (see 5.7.10), the device
3019 	 * server shall perform a preempt by doing the following as
3020 	 * an uninterrupted series of actions:
3021 	 *
3022 	 * a) Release the persistent reservation for the holder
3023 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3024 	 */
3025 	if (pr_reg_n != pr_res_holder)
3026 		__core_scsi3_complete_pro_release(dev,
3027 						  pr_res_holder->pr_reg_nacl,
3028 						  dev->dev_pr_res_holder, 0, 0);
3029 	/*
3030 	 * b) Remove the registrations for all I_T nexuses identified
3031 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3032 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3033 	 *    OUT command. If an all registrants persistent reservation
3034 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3035 	 *    is set to zero, then all registrations shall be removed
3036 	 *    except for that of the I_T nexus that is being used for
3037 	 *    the PERSISTENT RESERVE OUT command;
3038 	 */
3039 	spin_lock(&pr_tmpl->registration_lock);
3040 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3041 			&pr_tmpl->registration_list, pr_reg_list) {
3042 
3043 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3044 		if (calling_it_nexus)
3045 			continue;
3046 
3047 		if (pr_reg->pr_res_key != sa_res_key)
3048 			continue;
3049 
3050 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3051 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3052 		__core_scsi3_free_registration(dev, pr_reg,
3053 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3054 				calling_it_nexus);
3055 		/*
3056 		 * e) Establish a unit attention condition for the initiator
3057 		 *    port associated with every I_T nexus that lost its
3058 		 *    persistent reservation and/or registration, with the
3059 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3060 		 */
3061 		target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3062 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3063 	}
3064 	spin_unlock(&pr_tmpl->registration_lock);
3065 	/*
3066 	 * c) Establish a persistent reservation for the preempting
3067 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3068 	 */
3069 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3070 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3071 			type, scope, preempt_type);
3072 	/*
3073 	 * d) Process tasks as defined in 5.7.1;
3074 	 * e) See above..
3075 	 * f) If the type or scope has changed, then for every I_T nexus
3076 	 *    whose reservation key was not removed, except for the I_T
3077 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3078 	 *    received, the device server shall establish a unit
3079 	 *    attention condition for the initiator port associated with
3080 	 *    that I_T nexus, with the additional sense code set to
3081 	 *    RESERVATIONS RELEASED. If the type or scope have not
3082 	 *    changed, then no unit attention condition(s) shall be
3083 	 *    established for this reason.
3084 	 */
3085 	if ((prh_type != type) || (prh_scope != scope)) {
3086 		spin_lock(&pr_tmpl->registration_lock);
3087 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3088 				&pr_tmpl->registration_list, pr_reg_list) {
3089 
3090 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3091 			if (calling_it_nexus)
3092 				continue;
3093 
3094 			target_ua_allocate_lun(pr_reg->pr_reg_nacl,
3095 					pr_reg->pr_res_mapped_lun, 0x2A,
3096 					ASCQ_2AH_RESERVATIONS_RELEASED);
3097 		}
3098 		spin_unlock(&pr_tmpl->registration_lock);
3099 	}
3100 	spin_unlock(&dev->dev_reservation_lock);
3101 	/*
3102 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3103 	 * All received CDBs for the matching existing reservation and
3104 	 * registrations undergo ABORT_TASK logic.
3105 	 *
3106 	 * From there, core_scsi3_release_preempt_and_abort() will
3107 	 * release every registration in the list (which have already
3108 	 * been removed from the primary pr_reg list), except the
3109 	 * new persistent reservation holder, the calling Initiator Port.
3110 	 */
3111 	if (preempt_type == PREEMPT_AND_ABORT) {
3112 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3113 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3114 						pr_reg_n);
3115 	}
3116 
3117 	if (pr_tmpl->pr_aptpl_active)
3118 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3119 
3120 	core_scsi3_put_pr_reg(pr_reg_n);
3121 	core_scsi3_pr_generation(cmd->se_dev);
3122 	return 0;
3123 }
3124 
3125 static sense_reason_t
3126 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3127 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3128 {
3129 	switch (type) {
3130 	case PR_TYPE_WRITE_EXCLUSIVE:
3131 	case PR_TYPE_EXCLUSIVE_ACCESS:
3132 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3133 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3134 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3135 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3136 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3137 					      sa_res_key, preempt_type);
3138 	default:
3139 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3140 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3141 		return TCM_INVALID_CDB_FIELD;
3142 	}
3143 }
3144 
3145 
3146 static sense_reason_t
3147 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3148 		u64 sa_res_key, int aptpl, int unreg)
3149 {
3150 	struct se_session *se_sess = cmd->se_sess;
3151 	struct se_device *dev = cmd->se_dev;
3152 	struct se_dev_entry *dest_se_deve = NULL;
3153 	struct se_lun *se_lun = cmd->se_lun, *tmp_lun;
3154 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3155 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3156 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3157 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3158 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3159 	unsigned char *buf;
3160 	const unsigned char *initiator_str;
3161 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
3162 	u32 tid_len, tmp_tid_len;
3163 	int new_reg = 0, type, scope, matching_iname;
3164 	sense_reason_t ret;
3165 	unsigned short rtpi;
3166 	unsigned char proto_ident;
3167 
3168 	if (!se_sess || !se_lun) {
3169 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3170 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3171 	}
3172 
3173 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3174 	se_tpg = se_sess->se_tpg;
3175 	tf_ops = se_tpg->se_tpg_tfo;
3176 	/*
3177 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3178 	 *	Register behaviors for a REGISTER AND MOVE service action
3179 	 *
3180 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3181 	 */
3182 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3183 				se_sess);
3184 	if (!pr_reg) {
3185 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3186 			" *pr_reg for REGISTER_AND_MOVE\n");
3187 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3188 	}
3189 	/*
3190 	 * The provided reservation key much match the existing reservation key
3191 	 * provided during this initiator's I_T nexus registration.
3192 	 */
3193 	if (res_key != pr_reg->pr_res_key) {
3194 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3195 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3196 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3197 		ret = TCM_RESERVATION_CONFLICT;
3198 		goto out_put_pr_reg;
3199 	}
3200 	/*
3201 	 * The service active reservation key needs to be non zero
3202 	 */
3203 	if (!sa_res_key) {
3204 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3205 			" sa_res_key\n");
3206 		ret = TCM_INVALID_PARAMETER_LIST;
3207 		goto out_put_pr_reg;
3208 	}
3209 
3210 	/*
3211 	 * Determine the Relative Target Port Identifier where the reservation
3212 	 * will be moved to for the TransportID containing SCSI initiator WWN
3213 	 * information.
3214 	 */
3215 	buf = transport_kmap_data_sg(cmd);
3216 	if (!buf) {
3217 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3218 		goto out_put_pr_reg;
3219 	}
3220 
3221 	rtpi = get_unaligned_be16(&buf[18]);
3222 	tid_len = get_unaligned_be32(&buf[20]);
3223 	transport_kunmap_data_sg(cmd);
3224 	buf = NULL;
3225 
3226 	if ((tid_len + 24) != cmd->data_length) {
3227 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3228 			" does not equal CDB data_length: %u\n", tid_len,
3229 			cmd->data_length);
3230 		ret = TCM_INVALID_PARAMETER_LIST;
3231 		goto out_put_pr_reg;
3232 	}
3233 
3234 	spin_lock(&dev->se_port_lock);
3235 	list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
3236 		if (tmp_lun->lun_rtpi != rtpi)
3237 			continue;
3238 		dest_se_tpg = tmp_lun->lun_tpg;
3239 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3240 		if (!dest_tf_ops)
3241 			continue;
3242 
3243 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3244 		spin_unlock(&dev->se_port_lock);
3245 
3246 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3247 			pr_err("core_scsi3_tpg_depend_item() failed"
3248 				" for dest_se_tpg\n");
3249 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3250 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3251 			goto out_put_pr_reg;
3252 		}
3253 
3254 		spin_lock(&dev->se_port_lock);
3255 		break;
3256 	}
3257 	spin_unlock(&dev->se_port_lock);
3258 
3259 	if (!dest_se_tpg || !dest_tf_ops) {
3260 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3261 			" fabric ops from Relative Target Port Identifier:"
3262 			" %hu\n", rtpi);
3263 		ret = TCM_INVALID_PARAMETER_LIST;
3264 		goto out_put_pr_reg;
3265 	}
3266 
3267 	buf = transport_kmap_data_sg(cmd);
3268 	if (!buf) {
3269 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3270 		goto out_put_pr_reg;
3271 	}
3272 	proto_ident = (buf[24] & 0x0f);
3273 
3274 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3275 			" 0x%02x\n", proto_ident);
3276 
3277 	if (proto_ident != dest_se_tpg->proto_id) {
3278 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3279 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3280 			" from fabric: %s\n", proto_ident,
3281 			dest_se_tpg->proto_id,
3282 			dest_tf_ops->get_fabric_name());
3283 		ret = TCM_INVALID_PARAMETER_LIST;
3284 		goto out;
3285 	}
3286 	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
3287 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3288 	if (!initiator_str) {
3289 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3290 			" initiator_str from Transport ID\n");
3291 		ret = TCM_INVALID_PARAMETER_LIST;
3292 		goto out;
3293 	}
3294 
3295 	transport_kunmap_data_sg(cmd);
3296 	buf = NULL;
3297 
3298 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3299 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3300 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3301 		iport_ptr : "");
3302 	/*
3303 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3304 	 * action specifies a TransportID that is the same as the initiator port
3305 	 * of the I_T nexus for the command received, then the command shall
3306 	 * be terminated with CHECK CONDITION status, with the sense key set to
3307 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3308 	 * IN PARAMETER LIST.
3309 	 */
3310 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3311 	matching_iname = (!strcmp(initiator_str,
3312 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3313 	if (!matching_iname)
3314 		goto after_iport_check;
3315 
3316 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3317 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3318 			" matches: %s on received I_T Nexus\n", initiator_str,
3319 			pr_reg_nacl->initiatorname);
3320 		ret = TCM_INVALID_PARAMETER_LIST;
3321 		goto out;
3322 	}
3323 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3324 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3325 			" matches: %s %s on received I_T Nexus\n",
3326 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3327 			pr_reg->pr_reg_isid);
3328 		ret = TCM_INVALID_PARAMETER_LIST;
3329 		goto out;
3330 	}
3331 after_iport_check:
3332 	/*
3333 	 * Locate the destination struct se_node_acl from the received Transport ID
3334 	 */
3335 	mutex_lock(&dest_se_tpg->acl_node_mutex);
3336 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3337 				initiator_str);
3338 	if (dest_node_acl)
3339 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3340 	mutex_unlock(&dest_se_tpg->acl_node_mutex);
3341 
3342 	if (!dest_node_acl) {
3343 		pr_err("Unable to locate %s dest_node_acl for"
3344 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3345 			initiator_str);
3346 		ret = TCM_INVALID_PARAMETER_LIST;
3347 		goto out;
3348 	}
3349 
3350 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3351 		pr_err("core_scsi3_nodeacl_depend_item() for"
3352 			" dest_node_acl\n");
3353 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3354 		dest_node_acl = NULL;
3355 		ret = TCM_INVALID_PARAMETER_LIST;
3356 		goto out;
3357 	}
3358 
3359 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3360 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3361 		dest_node_acl->initiatorname);
3362 
3363 	/*
3364 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3365 	 * PORT IDENTIFIER.
3366 	 */
3367 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3368 	if (!dest_se_deve) {
3369 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3370 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3371 		ret = TCM_INVALID_PARAMETER_LIST;
3372 		goto out;
3373 	}
3374 
3375 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3376 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3377 		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
3378 		dest_se_deve = NULL;
3379 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3380 		goto out;
3381 	}
3382 
3383 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3384 		" ACL for dest_se_deve->mapped_lun: %llu\n",
3385 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3386 		dest_se_deve->mapped_lun);
3387 
3388 	/*
3389 	 * A persistent reservation needs to already existing in order to
3390 	 * successfully complete the REGISTER_AND_MOVE service action..
3391 	 */
3392 	spin_lock(&dev->dev_reservation_lock);
3393 	pr_res_holder = dev->dev_pr_res_holder;
3394 	if (!pr_res_holder) {
3395 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3396 			" currently held\n");
3397 		spin_unlock(&dev->dev_reservation_lock);
3398 		ret = TCM_INVALID_CDB_FIELD;
3399 		goto out;
3400 	}
3401 	/*
3402 	 * The received on I_T Nexus must be the reservation holder.
3403 	 *
3404 	 * From spc4r17 section 5.7.8  Table 50 --
3405 	 * 	Register behaviors for a REGISTER AND MOVE service action
3406 	 */
3407 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3408 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3409 			" Nexus is not reservation holder\n");
3410 		spin_unlock(&dev->dev_reservation_lock);
3411 		ret = TCM_RESERVATION_CONFLICT;
3412 		goto out;
3413 	}
3414 	/*
3415 	 * From spc4r17 section 5.7.8: registering and moving reservation
3416 	 *
3417 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3418 	 * action is received and the established persistent reservation is a
3419 	 * Write Exclusive - All Registrants type or Exclusive Access -
3420 	 * All Registrants type reservation, then the command shall be completed
3421 	 * with RESERVATION CONFLICT status.
3422 	 */
3423 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3424 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3425 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3426 			" reservation for type: %s\n",
3427 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3428 		spin_unlock(&dev->dev_reservation_lock);
3429 		ret = TCM_RESERVATION_CONFLICT;
3430 		goto out;
3431 	}
3432 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3433 	/*
3434 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3435 	 */
3436 	type = pr_res_holder->pr_res_type;
3437 	scope = pr_res_holder->pr_res_type;
3438 	/*
3439 	 * c) Associate the reservation key specified in the SERVICE ACTION
3440 	 *    RESERVATION KEY field with the I_T nexus specified as the
3441 	 *    destination of the register and move, where:
3442 	 *    A) The I_T nexus is specified by the TransportID and the
3443 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3444 	 *    B) Regardless of the TransportID format used, the association for
3445 	 *       the initiator port is based on either the initiator port name
3446 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3447 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3448 	 *       transport protocols where port names are not required;
3449 	 * d) Register the reservation key specified in the SERVICE ACTION
3450 	 *    RESERVATION KEY field;
3451 	 * e) Retain the reservation key specified in the SERVICE ACTION
3452 	 *    RESERVATION KEY field and associated information;
3453 	 *
3454 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3455 	 * register an I_T nexus that is already registered with the same
3456 	 * reservation key or a different reservation key.
3457 	 */
3458 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3459 					iport_ptr);
3460 	if (!dest_pr_reg) {
3461 		struct se_lun *dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
3462 				kref_read(&dest_se_deve->pr_kref) != 0);
3463 
3464 		spin_unlock(&dev->dev_reservation_lock);
3465 		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
3466 					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
3467 					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
3468 			ret = TCM_INVALID_PARAMETER_LIST;
3469 			goto out;
3470 		}
3471 		spin_lock(&dev->dev_reservation_lock);
3472 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3473 						iport_ptr);
3474 		new_reg = 1;
3475 	}
3476 	/*
3477 	 * f) Release the persistent reservation for the persistent reservation
3478 	 *    holder (i.e., the I_T nexus on which the
3479 	 */
3480 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3481 					  dev->dev_pr_res_holder, 0, 0);
3482 	/*
3483 	 * g) Move the persistent reservation to the specified I_T nexus using
3484 	 *    the same scope and type as the persistent reservation released in
3485 	 *    item f); and
3486 	 */
3487 	dev->dev_pr_res_holder = dest_pr_reg;
3488 	dest_pr_reg->pr_res_holder = 1;
3489 	dest_pr_reg->pr_res_type = type;
3490 	pr_reg->pr_res_scope = scope;
3491 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3492 	/*
3493 	 * Increment PRGeneration for existing registrations..
3494 	 */
3495 	if (!new_reg)
3496 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3497 	spin_unlock(&dev->dev_reservation_lock);
3498 
3499 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3500 		" created new reservation holder TYPE: %s on object RTPI:"
3501 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3502 		core_scsi3_pr_dump_type(type), rtpi,
3503 		dest_pr_reg->pr_res_generation);
3504 	pr_debug("SPC-3 PR Successfully moved reservation from"
3505 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3506 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3507 		i_buf, dest_tf_ops->get_fabric_name(),
3508 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3509 		iport_ptr : "");
3510 	/*
3511 	 * It is now safe to release configfs group dependencies for destination
3512 	 * of Transport ID Initiator Device/Port Identifier
3513 	 */
3514 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3515 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3516 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3517 	/*
3518 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3519 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3520 	 */
3521 	if (unreg) {
3522 		spin_lock(&pr_tmpl->registration_lock);
3523 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3524 		spin_unlock(&pr_tmpl->registration_lock);
3525 	} else
3526 		core_scsi3_put_pr_reg(pr_reg);
3527 
3528 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3529 
3530 	transport_kunmap_data_sg(cmd);
3531 
3532 	core_scsi3_put_pr_reg(dest_pr_reg);
3533 	return 0;
3534 out:
3535 	if (buf)
3536 		transport_kunmap_data_sg(cmd);
3537 	if (dest_se_deve)
3538 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3539 	if (dest_node_acl)
3540 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3541 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3542 
3543 out_put_pr_reg:
3544 	core_scsi3_put_pr_reg(pr_reg);
3545 	return ret;
3546 }
3547 
3548 /*
3549  * See spc4r17 section 6.14 Table 170
3550  */
3551 sense_reason_t
3552 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3553 {
3554 	struct se_device *dev = cmd->se_dev;
3555 	unsigned char *cdb = &cmd->t_task_cdb[0];
3556 	unsigned char *buf;
3557 	u64 res_key, sa_res_key;
3558 	int sa, scope, type, aptpl;
3559 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3560 	sense_reason_t ret;
3561 
3562 	/*
3563 	 * Following spc2r20 5.5.1 Reservations overview:
3564 	 *
3565 	 * If a logical unit has been reserved by any RESERVE command and is
3566 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3567 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3568 	 * initiator or service action and shall terminate with a RESERVATION
3569 	 * CONFLICT status.
3570 	 */
3571 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3572 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3573 			" SPC-2 reservation is held, returning"
3574 			" RESERVATION_CONFLICT\n");
3575 		return TCM_RESERVATION_CONFLICT;
3576 	}
3577 
3578 	/*
3579 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3580 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3581 	 */
3582 	if (!cmd->se_sess)
3583 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3584 
3585 	if (cmd->data_length < 24) {
3586 		pr_warn("SPC-PR: Received PR OUT parameter list"
3587 			" length too small: %u\n", cmd->data_length);
3588 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3589 	}
3590 
3591 	/*
3592 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3593 	 */
3594 	sa = (cdb[1] & 0x1f);
3595 	scope = (cdb[2] & 0xf0);
3596 	type = (cdb[2] & 0x0f);
3597 
3598 	buf = transport_kmap_data_sg(cmd);
3599 	if (!buf)
3600 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3601 
3602 	/*
3603 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3604 	 */
3605 	res_key = get_unaligned_be64(&buf[0]);
3606 	sa_res_key = get_unaligned_be64(&buf[8]);
3607 	/*
3608 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3609 	 * SCSI TransportIDs.
3610 	 */
3611 	if (sa != PRO_REGISTER_AND_MOVE) {
3612 		spec_i_pt = (buf[20] & 0x08);
3613 		all_tg_pt = (buf[20] & 0x04);
3614 		aptpl = (buf[20] & 0x01);
3615 	} else {
3616 		aptpl = (buf[17] & 0x01);
3617 		unreg = (buf[17] & 0x02);
3618 	}
3619 	/*
3620 	 * If the backend device has been configured to force APTPL metadata
3621 	 * write-out, go ahead and propigate aptpl=1 down now.
3622 	 */
3623 	if (dev->dev_attrib.force_pr_aptpl)
3624 		aptpl = 1;
3625 
3626 	transport_kunmap_data_sg(cmd);
3627 	buf = NULL;
3628 
3629 	/*
3630 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3631 	 */
3632 	if (spec_i_pt && (sa != PRO_REGISTER))
3633 		return TCM_INVALID_PARAMETER_LIST;
3634 
3635 	/*
3636 	 * From spc4r17 section 6.14:
3637 	 *
3638 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3639 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3640 	 * the command shall be terminated with CHECK CONDITION status, with
3641 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3642 	 * code set to PARAMETER LIST LENGTH ERROR.
3643 	 */
3644 	if (!spec_i_pt && (sa != PRO_REGISTER_AND_MOVE) &&
3645 	    (cmd->data_length != 24)) {
3646 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3647 			" list length: %u\n", cmd->data_length);
3648 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3649 	}
3650 
3651 	/*
3652 	 * (core_scsi3_emulate_pro_* function parameters
3653 	 * are defined by spc4r17 Table 174:
3654 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3655 	 */
3656 	switch (sa) {
3657 	case PRO_REGISTER:
3658 		ret = core_scsi3_emulate_pro_register(cmd,
3659 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3660 		break;
3661 	case PRO_RESERVE:
3662 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3663 		break;
3664 	case PRO_RELEASE:
3665 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3666 		break;
3667 	case PRO_CLEAR:
3668 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3669 		break;
3670 	case PRO_PREEMPT:
3671 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3672 					res_key, sa_res_key, PREEMPT);
3673 		break;
3674 	case PRO_PREEMPT_AND_ABORT:
3675 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3676 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3677 		break;
3678 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3679 		ret = core_scsi3_emulate_pro_register(cmd,
3680 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3681 		break;
3682 	case PRO_REGISTER_AND_MOVE:
3683 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3684 				sa_res_key, aptpl, unreg);
3685 		break;
3686 	default:
3687 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3688 			" action: 0x%02x\n", sa);
3689 		return TCM_INVALID_CDB_FIELD;
3690 	}
3691 
3692 	if (!ret)
3693 		target_complete_cmd(cmd, GOOD);
3694 	return ret;
3695 }
3696 
3697 /*
3698  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3699  *
3700  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3701  */
3702 static sense_reason_t
3703 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3704 {
3705 	struct se_device *dev = cmd->se_dev;
3706 	struct t10_pr_registration *pr_reg;
3707 	unsigned char *buf;
3708 	u32 add_len = 0, off = 8;
3709 
3710 	if (cmd->data_length < 8) {
3711 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3712 			" too small\n", cmd->data_length);
3713 		return TCM_INVALID_CDB_FIELD;
3714 	}
3715 
3716 	buf = transport_kmap_data_sg(cmd);
3717 	if (!buf)
3718 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3719 
3720 	put_unaligned_be32(dev->t10_pr.pr_generation, buf);
3721 
3722 	spin_lock(&dev->t10_pr.registration_lock);
3723 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3724 			pr_reg_list) {
3725 		/*
3726 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3727 		 * next reservation key list descriptor.
3728 		 */
3729 		if ((add_len + 8) > (cmd->data_length - 8))
3730 			break;
3731 
3732 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3733 		off += 8;
3734 		add_len += 8;
3735 	}
3736 	spin_unlock(&dev->t10_pr.registration_lock);
3737 
3738 	put_unaligned_be32(add_len, &buf[4]);
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 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3770 
3771 	spin_lock(&dev->dev_reservation_lock);
3772 	pr_reg = dev->dev_pr_res_holder;
3773 	if (pr_reg) {
3774 		/*
3775 		 * Set the hardcoded Additional Length
3776 		 */
3777 		put_unaligned_be32(add_len, &buf[4]);
3778 
3779 		if (cmd->data_length < 22)
3780 			goto err;
3781 
3782 		/*
3783 		 * Set the Reservation key.
3784 		 *
3785 		 * From spc4r17, section 5.7.10:
3786 		 * A persistent reservation holder has its reservation key
3787 		 * returned in the parameter data from a PERSISTENT
3788 		 * RESERVE IN command with READ RESERVATION service action as
3789 		 * follows:
3790 		 * a) For a persistent reservation of the type Write Exclusive
3791 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3792 		 *      the reservation key shall be set to zero; or
3793 		 * b) For all other persistent reservation types, the
3794 		 *    reservation key shall be set to the registered
3795 		 *    reservation key for the I_T nexus that holds the
3796 		 *    persistent reservation.
3797 		 */
3798 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3799 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3800 			pr_res_key = 0;
3801 		else
3802 			pr_res_key = pr_reg->pr_res_key;
3803 
3804 		put_unaligned_be64(pr_res_key, &buf[8]);
3805 		/*
3806 		 * Set the SCOPE and TYPE
3807 		 */
3808 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3809 			  (pr_reg->pr_res_type & 0x0f);
3810 	}
3811 
3812 err:
3813 	spin_unlock(&dev->dev_reservation_lock);
3814 	transport_kunmap_data_sg(cmd);
3815 
3816 	return 0;
3817 }
3818 
3819 /*
3820  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3821  *
3822  * See spc4r17 section 6.13.4 Table 165
3823  */
3824 static sense_reason_t
3825 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3826 {
3827 	struct se_device *dev = cmd->se_dev;
3828 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3829 	unsigned char *buf;
3830 	u16 add_len = 8; /* Hardcoded to 8. */
3831 
3832 	if (cmd->data_length < 6) {
3833 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3834 			" %u too small\n", cmd->data_length);
3835 		return TCM_INVALID_CDB_FIELD;
3836 	}
3837 
3838 	buf = transport_kmap_data_sg(cmd);
3839 	if (!buf)
3840 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3841 
3842 	put_unaligned_be16(add_len, &buf[0]);
3843 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3844 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3845 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3846 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3847 	/*
3848 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3849 	 * set the TMV: Task Mask Valid bit.
3850 	 */
3851 	buf[3] |= 0x80;
3852 	/*
3853 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3854 	 */
3855 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3856 	/*
3857 	 * PTPL_A: Persistence across Target Power Loss Active bit
3858 	 */
3859 	if (pr_tmpl->pr_aptpl_active)
3860 		buf[3] |= 0x01;
3861 	/*
3862 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3863 	 */
3864 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3865 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3866 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3867 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3868 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3869 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3870 
3871 	transport_kunmap_data_sg(cmd);
3872 
3873 	return 0;
3874 }
3875 
3876 /*
3877  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3878  *
3879  * See spc4r17 section 6.13.5 Table 168 and 169
3880  */
3881 static sense_reason_t
3882 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3883 {
3884 	struct se_device *dev = cmd->se_dev;
3885 	struct se_node_acl *se_nacl;
3886 	struct se_portal_group *se_tpg;
3887 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3888 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3889 	unsigned char *buf;
3890 	u32 add_desc_len = 0, add_len = 0;
3891 	u32 off = 8; /* off into first Full Status descriptor */
3892 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3893 	int exp_desc_len, desc_len;
3894 	bool all_reg = false;
3895 
3896 	if (cmd->data_length < 8) {
3897 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3898 			" too small\n", cmd->data_length);
3899 		return TCM_INVALID_CDB_FIELD;
3900 	}
3901 
3902 	buf = transport_kmap_data_sg(cmd);
3903 	if (!buf)
3904 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3905 
3906 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3907 
3908 	spin_lock(&dev->dev_reservation_lock);
3909 	if (dev->dev_pr_res_holder) {
3910 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3911 
3912 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3913 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3914 			all_reg = true;
3915 			pr_res_type = pr_holder->pr_res_type;
3916 			pr_res_scope = pr_holder->pr_res_scope;
3917 		}
3918 	}
3919 	spin_unlock(&dev->dev_reservation_lock);
3920 
3921 	spin_lock(&pr_tmpl->registration_lock);
3922 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3923 			&pr_tmpl->registration_list, pr_reg_list) {
3924 
3925 		se_nacl = pr_reg->pr_reg_nacl;
3926 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3927 		add_desc_len = 0;
3928 
3929 		atomic_inc_mb(&pr_reg->pr_res_holders);
3930 		spin_unlock(&pr_tmpl->registration_lock);
3931 		/*
3932 		 * Determine expected length of $FABRIC_MOD specific
3933 		 * TransportID full status descriptor..
3934 		 */
3935 		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
3936 					&format_code);
3937 		if (exp_desc_len < 0 ||
3938 		    exp_desc_len + add_len > cmd->data_length) {
3939 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3940 				" out of buffer: %d\n", cmd->data_length);
3941 			spin_lock(&pr_tmpl->registration_lock);
3942 			atomic_dec_mb(&pr_reg->pr_res_holders);
3943 			break;
3944 		}
3945 		/*
3946 		 * Set RESERVATION KEY
3947 		 */
3948 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3949 		off += 8;
3950 		off += 4; /* Skip Over Reserved area */
3951 
3952 		/*
3953 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3954 		 */
3955 		if (pr_reg->pr_reg_all_tg_pt)
3956 			buf[off] = 0x02;
3957 		/*
3958 		 * The struct se_lun pointer will be present for the
3959 		 * reservation holder for PR_HOLDER bit.
3960 		 *
3961 		 * Also, if this registration is the reservation
3962 		 * holder or there is an All Registrants reservation
3963 		 * active, fill in SCOPE and TYPE in the next byte.
3964 		 */
3965 		if (pr_reg->pr_res_holder) {
3966 			buf[off++] |= 0x01;
3967 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3968 				     (pr_reg->pr_res_type & 0x0f);
3969 		} else if (all_reg) {
3970 			buf[off++] |= 0x01;
3971 			buf[off++] = (pr_res_scope & 0xf0) |
3972 				     (pr_res_type & 0x0f);
3973 		} else {
3974 			off += 2;
3975 		}
3976 
3977 		off += 4; /* Skip over reserved area */
3978 		/*
3979 		 * From spc4r17 6.3.15:
3980 		 *
3981 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
3982 		 * IDENTIFIER field contains the relative port identifier (see
3983 		 * 3.1.120) of the target port that is part of the I_T nexus
3984 		 * described by this full status descriptor. If the ALL_TG_PT
3985 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
3986 		 * IDENTIFIER field are not defined by this standard.
3987 		 */
3988 		if (!pr_reg->pr_reg_all_tg_pt) {
3989 			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;
3990 
3991 			put_unaligned_be16(sep_rtpi, &buf[off]);
3992 			off += 2;
3993 		} else
3994 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
3995 
3996 		buf[off+4] = se_tpg->proto_id;
3997 
3998 		/*
3999 		 * Now, have the $FABRIC_MOD fill in the transport ID.
4000 		 */
4001 		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
4002 				&format_code, &buf[off+4]);
4003 
4004 		spin_lock(&pr_tmpl->registration_lock);
4005 		atomic_dec_mb(&pr_reg->pr_res_holders);
4006 
4007 		if (desc_len < 0)
4008 			break;
4009 		/*
4010 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4011 		 */
4012 		put_unaligned_be32(desc_len, &buf[off]);
4013 		/*
4014 		 * Size of full desctipor header minus TransportID
4015 		 * containing $FABRIC_MOD specific) initiator device/port
4016 		 * WWN information.
4017 		 *
4018 		 *  See spc4r17 Section 6.13.5 Table 169
4019 		 */
4020 		add_desc_len = (24 + desc_len);
4021 
4022 		off += desc_len;
4023 		add_len += add_desc_len;
4024 	}
4025 	spin_unlock(&pr_tmpl->registration_lock);
4026 	/*
4027 	 * Set ADDITIONAL_LENGTH
4028 	 */
4029 	put_unaligned_be32(add_len, &buf[4]);
4030 
4031 	transport_kunmap_data_sg(cmd);
4032 
4033 	return 0;
4034 }
4035 
4036 sense_reason_t
4037 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4038 {
4039 	sense_reason_t ret;
4040 
4041 	/*
4042 	 * Following spc2r20 5.5.1 Reservations overview:
4043 	 *
4044 	 * If a logical unit has been reserved by any RESERVE command and is
4045 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4046 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4047 	 * initiator or service action and shall terminate with a RESERVATION
4048 	 * CONFLICT status.
4049 	 */
4050 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4051 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4052 			" SPC-2 reservation is held, returning"
4053 			" RESERVATION_CONFLICT\n");
4054 		return TCM_RESERVATION_CONFLICT;
4055 	}
4056 
4057 	switch (cmd->t_task_cdb[1] & 0x1f) {
4058 	case PRI_READ_KEYS:
4059 		ret = core_scsi3_pri_read_keys(cmd);
4060 		break;
4061 	case PRI_READ_RESERVATION:
4062 		ret = core_scsi3_pri_read_reservation(cmd);
4063 		break;
4064 	case PRI_REPORT_CAPABILITIES:
4065 		ret = core_scsi3_pri_report_capabilities(cmd);
4066 		break;
4067 	case PRI_READ_FULL_STATUS:
4068 		ret = core_scsi3_pri_read_full_status(cmd);
4069 		break;
4070 	default:
4071 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4072 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4073 		return TCM_INVALID_CDB_FIELD;
4074 	}
4075 
4076 	if (!ret)
4077 		target_complete_cmd(cmd, GOOD);
4078 	return ret;
4079 }
4080 
4081 sense_reason_t
4082 target_check_reservation(struct se_cmd *cmd)
4083 {
4084 	struct se_device *dev = cmd->se_dev;
4085 	sense_reason_t ret;
4086 
4087 	if (!cmd->se_sess)
4088 		return 0;
4089 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4090 		return 0;
4091 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
4092 		return 0;
4093 
4094 	spin_lock(&dev->dev_reservation_lock);
4095 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4096 		ret = target_scsi2_reservation_check(cmd);
4097 	else
4098 		ret = target_scsi3_pr_reservation_check(cmd);
4099 	spin_unlock(&dev->dev_reservation_lock);
4100 
4101 	return ret;
4102 }
4103