1 /*******************************************************************************
2  * Filename:  target_core_pr.c
3  *
4  * This file contains SPC-3 compliant persistent reservations and
5  * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
6  *
7  * (c) Copyright 2009-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24  *
25  ******************************************************************************/
26 
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/list.h>
30 #include <linux/file.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_cmnd.h>
33 #include <asm/unaligned.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_backend.h>
37 #include <target/target_core_fabric.h>
38 
39 #include "target_core_internal.h"
40 #include "target_core_pr.h"
41 #include "target_core_ua.h"
42 
43 /*
44  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
45  */
46 struct pr_transport_id_holder {
47 	struct t10_pr_registration *dest_pr_reg;
48 	struct se_portal_group *dest_tpg;
49 	struct se_node_acl *dest_node_acl;
50 	struct se_dev_entry *dest_se_deve;
51 	struct list_head dest_list;
52 };
53 
54 void core_pr_dump_initiator_port(
55 	struct t10_pr_registration *pr_reg,
56 	char *buf,
57 	u32 size)
58 {
59 	if (!pr_reg->isid_present_at_reg)
60 		buf[0] = '\0';
61 
62 	snprintf(buf, size, ",i,0x%s", pr_reg->pr_reg_isid);
63 }
64 
65 enum register_type {
66 	REGISTER,
67 	REGISTER_AND_IGNORE_EXISTING_KEY,
68 	REGISTER_AND_MOVE,
69 };
70 
71 enum preempt_type {
72 	PREEMPT,
73 	PREEMPT_AND_ABORT,
74 };
75 
76 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
77 					      struct t10_pr_registration *, int, int);
78 
79 static int is_reservation_holder(
80 	struct t10_pr_registration *pr_res_holder,
81 	struct t10_pr_registration *pr_reg)
82 {
83 	int pr_res_type;
84 
85 	if (pr_res_holder) {
86 		pr_res_type = pr_res_holder->pr_res_type;
87 
88 		return pr_res_holder == pr_reg ||
89 		       pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
90 		       pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG;
91 	}
92 	return 0;
93 }
94 
95 static sense_reason_t
96 target_scsi2_reservation_check(struct se_cmd *cmd)
97 {
98 	struct se_device *dev = cmd->se_dev;
99 	struct se_session *sess = cmd->se_sess;
100 
101 	switch (cmd->t_task_cdb[0]) {
102 	case INQUIRY:
103 	case RELEASE:
104 	case RELEASE_10:
105 		return 0;
106 	default:
107 		break;
108 	}
109 
110 	if (!dev->dev_reserved_node_acl || !sess)
111 		return 0;
112 
113 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
114 		return TCM_RESERVATION_CONFLICT;
115 
116 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
117 		if (dev->dev_res_bin_isid != sess->sess_bin_isid)
118 			return TCM_RESERVATION_CONFLICT;
119 	}
120 
121 	return 0;
122 }
123 
124 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
125 					struct se_node_acl *, struct se_session *);
126 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
127 
128 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
129 {
130 	struct se_session *se_sess = cmd->se_sess;
131 	struct se_device *dev = cmd->se_dev;
132 	struct t10_pr_registration *pr_reg;
133 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
134 	int conflict = 0;
135 
136 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
137 			se_sess);
138 	if (pr_reg) {
139 		/*
140 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
141 		 * behavior
142 		 *
143 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
144 		 * status, but no reservation shall be established and the
145 		 * persistent reservation shall not be changed, if the command
146 		 * is received from a) and b) below.
147 		 *
148 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
149 		 * status, but the persistent reservation shall not be released,
150 		 * if the command is received from a) and b)
151 		 *
152 		 * a) An I_T nexus that is a persistent reservation holder; or
153 		 * b) An I_T nexus that is registered if a registrants only or
154 		 *    all registrants type persistent reservation is present.
155 		 *
156 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
157 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
158 		 * as defined in SPC-2.
159 		 */
160 		if (pr_reg->pr_res_holder) {
161 			core_scsi3_put_pr_reg(pr_reg);
162 			return 1;
163 		}
164 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
165 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
166 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
167 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
168 			core_scsi3_put_pr_reg(pr_reg);
169 			return 1;
170 		}
171 		core_scsi3_put_pr_reg(pr_reg);
172 		conflict = 1;
173 	} else {
174 		/*
175 		 * Following spc2r20 5.5.1 Reservations overview:
176 		 *
177 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
178 		 * command with the REGISTER or the REGISTER AND IGNORE
179 		 * EXISTING KEY service action and is still registered by any
180 		 * initiator, all RESERVE commands and all RELEASE commands
181 		 * regardless of initiator shall conflict and shall terminate
182 		 * with a RESERVATION CONFLICT status.
183 		 */
184 		spin_lock(&pr_tmpl->registration_lock);
185 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
186 		spin_unlock(&pr_tmpl->registration_lock);
187 	}
188 
189 	if (conflict) {
190 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
191 			" while active SPC-3 registrations exist,"
192 			" returning RESERVATION_CONFLICT\n");
193 		return -EBUSY;
194 	}
195 
196 	return 0;
197 }
198 
199 sense_reason_t
200 target_scsi2_reservation_release(struct se_cmd *cmd)
201 {
202 	struct se_device *dev = cmd->se_dev;
203 	struct se_session *sess = cmd->se_sess;
204 	struct se_portal_group *tpg;
205 	int rc;
206 
207 	if (!sess || !sess->se_tpg)
208 		goto out;
209 	rc = target_check_scsi2_reservation_conflict(cmd);
210 	if (rc == 1)
211 		goto out;
212 	if (rc < 0)
213 		return TCM_RESERVATION_CONFLICT;
214 
215 	spin_lock(&dev->dev_reservation_lock);
216 	if (!dev->dev_reserved_node_acl || !sess)
217 		goto out_unlock;
218 
219 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
220 		goto out_unlock;
221 
222 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
223 		goto out_unlock;
224 
225 	dev->dev_reserved_node_acl = NULL;
226 	dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
227 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
228 		dev->dev_res_bin_isid = 0;
229 		dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS_WITH_ISID;
230 	}
231 	tpg = sess->se_tpg;
232 	pr_debug("SCSI-2 Released reservation for %s LUN: %u ->"
233 		" MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
234 		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
235 		sess->se_node_acl->initiatorname);
236 
237 out_unlock:
238 	spin_unlock(&dev->dev_reservation_lock);
239 out:
240 	target_complete_cmd(cmd, GOOD);
241 	return 0;
242 }
243 
244 sense_reason_t
245 target_scsi2_reservation_reserve(struct se_cmd *cmd)
246 {
247 	struct se_device *dev = cmd->se_dev;
248 	struct se_session *sess = cmd->se_sess;
249 	struct se_portal_group *tpg;
250 	sense_reason_t ret = 0;
251 	int rc;
252 
253 	if ((cmd->t_task_cdb[1] & 0x01) &&
254 	    (cmd->t_task_cdb[1] & 0x02)) {
255 		pr_err("LongIO and Obselete Bits set, returning"
256 				" ILLEGAL_REQUEST\n");
257 		return TCM_UNSUPPORTED_SCSI_OPCODE;
258 	}
259 	/*
260 	 * This is currently the case for target_core_mod passthrough struct se_cmd
261 	 * ops
262 	 */
263 	if (!sess || !sess->se_tpg)
264 		goto out;
265 	rc = target_check_scsi2_reservation_conflict(cmd);
266 	if (rc == 1)
267 		goto out;
268 
269 	if (rc < 0)
270 		return TCM_RESERVATION_CONFLICT;
271 
272 	tpg = sess->se_tpg;
273 	spin_lock(&dev->dev_reservation_lock);
274 	if (dev->dev_reserved_node_acl &&
275 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
276 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
277 			tpg->se_tpg_tfo->get_fabric_name());
278 		pr_err("Original reserver LUN: %u %s\n",
279 			cmd->se_lun->unpacked_lun,
280 			dev->dev_reserved_node_acl->initiatorname);
281 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
282 			" from %s \n", cmd->se_lun->unpacked_lun,
283 			cmd->orig_fe_lun,
284 			sess->se_node_acl->initiatorname);
285 		ret = TCM_RESERVATION_CONFLICT;
286 		goto out_unlock;
287 	}
288 
289 	dev->dev_reserved_node_acl = sess->se_node_acl;
290 	dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS;
291 	if (sess->sess_bin_isid != 0) {
292 		dev->dev_res_bin_isid = sess->sess_bin_isid;
293 		dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS_WITH_ISID;
294 	}
295 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
296 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
297 		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
298 		sess->se_node_acl->initiatorname);
299 
300 out_unlock:
301 	spin_unlock(&dev->dev_reservation_lock);
302 out:
303 	if (!ret)
304 		target_complete_cmd(cmd, GOOD);
305 	return ret;
306 }
307 
308 
309 /*
310  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
311  *
312  * This function is called by those initiator ports who are *NOT*
313  * the active PR reservation holder when a reservation is present.
314  */
315 static int core_scsi3_pr_seq_non_holder(struct se_cmd *cmd, u32 pr_reg_type,
316 					bool isid_mismatch)
317 {
318 	unsigned char *cdb = cmd->t_task_cdb;
319 	struct se_session *se_sess = cmd->se_sess;
320 	struct se_node_acl *nacl = se_sess->se_node_acl;
321 	int other_cdb = 0;
322 	int registered_nexus = 0, ret = 1; /* Conflict by default */
323 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
324 	int we = 0; /* Write Exclusive */
325 	int legacy = 0; /* Act like a legacy device and return
326 			 * RESERVATION CONFLICT on some CDBs */
327 
328 	if (isid_mismatch) {
329 		registered_nexus = 0;
330 	} else {
331 		struct se_dev_entry *se_deve;
332 
333 		rcu_read_lock();
334 		se_deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
335 		if (se_deve)
336 			registered_nexus = test_bit(DEF_PR_REG_ACTIVE,
337 						    &se_deve->deve_flags);
338 		rcu_read_unlock();
339 	}
340 
341 	switch (pr_reg_type) {
342 	case PR_TYPE_WRITE_EXCLUSIVE:
343 		we = 1;
344 	case PR_TYPE_EXCLUSIVE_ACCESS:
345 		/*
346 		 * Some commands are only allowed for the persistent reservation
347 		 * holder.
348 		 */
349 		break;
350 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
351 		we = 1;
352 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
353 		/*
354 		 * Some commands are only allowed for registered I_T Nexuses.
355 		 */
356 		reg_only = 1;
357 		break;
358 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
359 		we = 1;
360 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
361 		/*
362 		 * Each registered I_T Nexus is a reservation holder.
363 		 */
364 		all_reg = 1;
365 		break;
366 	default:
367 		return -EINVAL;
368 	}
369 	/*
370 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
371 	 */
372 	switch (cdb[0]) {
373 	case SECURITY_PROTOCOL_IN:
374 		if (registered_nexus)
375 			return 0;
376 		ret = (we) ? 0 : 1;
377 		break;
378 	case MODE_SENSE:
379 	case MODE_SENSE_10:
380 	case READ_ATTRIBUTE:
381 	case READ_BUFFER:
382 	case RECEIVE_DIAGNOSTIC:
383 		if (legacy) {
384 			ret = 1;
385 			break;
386 		}
387 		if (registered_nexus) {
388 			ret = 0;
389 			break;
390 		}
391 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
392 		break;
393 	case PERSISTENT_RESERVE_OUT:
394 		/*
395 		 * This follows PERSISTENT_RESERVE_OUT service actions that
396 		 * are allowed in the presence of various reservations.
397 		 * See spc4r17, table 46
398 		 */
399 		switch (cdb[1] & 0x1f) {
400 		case PRO_CLEAR:
401 		case PRO_PREEMPT:
402 		case PRO_PREEMPT_AND_ABORT:
403 			ret = (registered_nexus) ? 0 : 1;
404 			break;
405 		case PRO_REGISTER:
406 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
407 			ret = 0;
408 			break;
409 		case PRO_REGISTER_AND_MOVE:
410 		case PRO_RESERVE:
411 			ret = 1;
412 			break;
413 		case PRO_RELEASE:
414 			ret = (registered_nexus) ? 0 : 1;
415 			break;
416 		default:
417 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
418 				" action: 0x%02x\n", cdb[1] & 0x1f);
419 			return -EINVAL;
420 		}
421 		break;
422 	case RELEASE:
423 	case RELEASE_10:
424 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
425 		ret = 0;
426 		break;
427 	case RESERVE:
428 	case RESERVE_10:
429 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
430 		ret = 0;
431 		break;
432 	case TEST_UNIT_READY:
433 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
434 		break;
435 	case MAINTENANCE_IN:
436 		switch (cdb[1] & 0x1f) {
437 		case MI_MANAGEMENT_PROTOCOL_IN:
438 			if (registered_nexus) {
439 				ret = 0;
440 				break;
441 			}
442 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
443 			break;
444 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
445 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
446 			if (legacy) {
447 				ret = 1;
448 				break;
449 			}
450 			if (registered_nexus) {
451 				ret = 0;
452 				break;
453 			}
454 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
455 			break;
456 		case MI_REPORT_ALIASES:
457 		case MI_REPORT_IDENTIFYING_INFORMATION:
458 		case MI_REPORT_PRIORITY:
459 		case MI_REPORT_TARGET_PGS:
460 		case MI_REPORT_TIMESTAMP:
461 			ret = 0; /* Allowed */
462 			break;
463 		default:
464 			pr_err("Unknown MI Service Action: 0x%02x\n",
465 				(cdb[1] & 0x1f));
466 			return -EINVAL;
467 		}
468 		break;
469 	case ACCESS_CONTROL_IN:
470 	case ACCESS_CONTROL_OUT:
471 	case INQUIRY:
472 	case LOG_SENSE:
473 	case SERVICE_ACTION_IN_12:
474 	case REPORT_LUNS:
475 	case REQUEST_SENSE:
476 	case PERSISTENT_RESERVE_IN:
477 		ret = 0; /*/ Allowed CDBs */
478 		break;
479 	default:
480 		other_cdb = 1;
481 		break;
482 	}
483 	/*
484 	 * Case where the CDB is explicitly allowed in the above switch
485 	 * statement.
486 	 */
487 	if (!ret && !other_cdb) {
488 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
489 			" reservation holder\n", cdb[0],
490 			core_scsi3_pr_dump_type(pr_reg_type));
491 
492 		return ret;
493 	}
494 	/*
495 	 * Check if write exclusive initiator ports *NOT* holding the
496 	 * WRITE_EXCLUSIVE_* reservation.
497 	 */
498 	if (we && !registered_nexus) {
499 		if (cmd->data_direction == DMA_TO_DEVICE) {
500 			/*
501 			 * Conflict for write exclusive
502 			 */
503 			pr_debug("%s Conflict for unregistered nexus"
504 				" %s CDB: 0x%02x to %s reservation\n",
505 				transport_dump_cmd_direction(cmd),
506 				se_sess->se_node_acl->initiatorname, cdb[0],
507 				core_scsi3_pr_dump_type(pr_reg_type));
508 			return 1;
509 		} else {
510 			/*
511 			 * Allow non WRITE CDBs for all Write Exclusive
512 			 * PR TYPEs to pass for registered and
513 			 * non-registered_nexuxes NOT holding the reservation.
514 			 *
515 			 * We only make noise for the unregisterd nexuses,
516 			 * as we expect registered non-reservation holding
517 			 * nexuses to issue CDBs.
518 			 */
519 
520 			if (!registered_nexus) {
521 				pr_debug("Allowing implicit CDB: 0x%02x"
522 					" for %s reservation on unregistered"
523 					" nexus\n", cdb[0],
524 					core_scsi3_pr_dump_type(pr_reg_type));
525 			}
526 
527 			return 0;
528 		}
529 	} else if ((reg_only) || (all_reg)) {
530 		if (registered_nexus) {
531 			/*
532 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
533 			 * allow commands from registered nexuses.
534 			 */
535 
536 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
537 				" reservation\n", cdb[0],
538 				core_scsi3_pr_dump_type(pr_reg_type));
539 
540 			return 0;
541 		}
542        } else if (we && registered_nexus) {
543                /*
544                 * Reads are allowed for Write Exclusive locks
545                 * from all registrants.
546                 */
547                if (cmd->data_direction == DMA_FROM_DEVICE) {
548                        pr_debug("Allowing READ CDB: 0x%02x for %s"
549                                " reservation\n", cdb[0],
550                                core_scsi3_pr_dump_type(pr_reg_type));
551 
552                        return 0;
553                }
554 	}
555 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
556 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
557 		(registered_nexus) ? "" : "un",
558 		se_sess->se_node_acl->initiatorname, cdb[0],
559 		core_scsi3_pr_dump_type(pr_reg_type));
560 
561 	return 1; /* Conflict by default */
562 }
563 
564 static sense_reason_t
565 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
566 {
567 	struct se_device *dev = cmd->se_dev;
568 	struct se_session *sess = cmd->se_sess;
569 	u32 pr_reg_type;
570 	bool isid_mismatch = false;
571 
572 	if (!dev->dev_pr_res_holder)
573 		return 0;
574 
575 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
576 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
577 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
578 		goto check_nonholder;
579 
580 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
581 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
582 		    sess->sess_bin_isid) {
583 			isid_mismatch = true;
584 			goto check_nonholder;
585 		}
586 	}
587 
588 	return 0;
589 
590 check_nonholder:
591 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type, isid_mismatch))
592 		return TCM_RESERVATION_CONFLICT;
593 	return 0;
594 }
595 
596 static u32 core_scsi3_pr_generation(struct se_device *dev)
597 {
598 	u32 prg;
599 
600 	/*
601 	 * PRGeneration field shall contain the value of a 32-bit wrapping
602 	 * counter mainted by the device server.
603 	 *
604 	 * Note that this is done regardless of Active Persist across
605 	 * Target PowerLoss (APTPL)
606 	 *
607 	 * See spc4r17 section 6.3.12 READ_KEYS service action
608 	 */
609 	spin_lock(&dev->dev_reservation_lock);
610 	prg = dev->t10_pr.pr_generation++;
611 	spin_unlock(&dev->dev_reservation_lock);
612 
613 	return prg;
614 }
615 
616 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
617 	struct se_device *dev,
618 	struct se_node_acl *nacl,
619 	struct se_lun *lun,
620 	struct se_dev_entry *deve,
621 	u32 mapped_lun,
622 	unsigned char *isid,
623 	u64 sa_res_key,
624 	int all_tg_pt,
625 	int aptpl)
626 {
627 	struct t10_pr_registration *pr_reg;
628 
629 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
630 	if (!pr_reg) {
631 		pr_err("Unable to allocate struct t10_pr_registration\n");
632 		return NULL;
633 	}
634 
635 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
636 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
637 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
638 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
639 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
640 	atomic_set(&pr_reg->pr_res_holders, 0);
641 	pr_reg->pr_reg_nacl = nacl;
642 	pr_reg->pr_reg_deve = deve;
643 	pr_reg->pr_res_mapped_lun = mapped_lun;
644 	pr_reg->pr_aptpl_target_lun = lun->unpacked_lun;
645 	pr_reg->tg_pt_sep_rtpi = lun->lun_sep->sep_rtpi;
646 	pr_reg->pr_res_key = sa_res_key;
647 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
648 	pr_reg->pr_reg_aptpl = aptpl;
649 	/*
650 	 * If an ISID value for this SCSI Initiator Port exists,
651 	 * save it to the registration now.
652 	 */
653 	if (isid != NULL) {
654 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
655 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
656 		pr_reg->isid_present_at_reg = 1;
657 	}
658 
659 	return pr_reg;
660 }
661 
662 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
663 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
664 
665 /*
666  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
667  * modes.
668  */
669 static struct t10_pr_registration *__core_scsi3_alloc_registration(
670 	struct se_device *dev,
671 	struct se_node_acl *nacl,
672 	struct se_lun *lun,
673 	struct se_dev_entry *deve,
674 	u32 mapped_lun,
675 	unsigned char *isid,
676 	u64 sa_res_key,
677 	int all_tg_pt,
678 	int aptpl)
679 {
680 	struct se_dev_entry *deve_tmp;
681 	struct se_node_acl *nacl_tmp;
682 	struct se_lun_acl *lacl_tmp;
683 	struct se_lun *lun_tmp;
684 	struct se_port *port, *port_tmp;
685 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
686 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
687 	int ret;
688 	/*
689 	 * Create a registration for the I_T Nexus upon which the
690 	 * PROUT REGISTER was received.
691 	 */
692 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, lun, deve, mapped_lun,
693 						    isid, sa_res_key, all_tg_pt,
694 						    aptpl);
695 	if (!pr_reg)
696 		return NULL;
697 	/*
698 	 * Return pointer to pr_reg for ALL_TG_PT=0
699 	 */
700 	if (!all_tg_pt)
701 		return pr_reg;
702 	/*
703 	 * Create list of matching SCSI Initiator Port registrations
704 	 * for ALL_TG_PT=1
705 	 */
706 	spin_lock(&dev->se_port_lock);
707 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
708 		atomic_inc_mb(&port->sep_tg_pt_ref_cnt);
709 		spin_unlock(&dev->se_port_lock);
710 
711 		spin_lock_bh(&port->sep_alua_lock);
712 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
713 					alua_port_list) {
714 			/*
715 			 * This pointer will be NULL for demo mode MappedLUNs
716 			 * that have not been make explicit via a ConfigFS
717 			 * MappedLUN group for the SCSI Initiator Node ACL.
718 			 */
719 			if (!deve_tmp->se_lun_acl)
720 				continue;
721 
722 			lacl_tmp = rcu_dereference_check(deve_tmp->se_lun_acl,
723 						lockdep_is_held(&port->sep_alua_lock));
724 			nacl_tmp = lacl_tmp->se_lun_nacl;
725 			/*
726 			 * Skip the matching struct se_node_acl that is allocated
727 			 * above..
728 			 */
729 			if (nacl == nacl_tmp)
730 				continue;
731 			/*
732 			 * Only perform PR registrations for target ports on
733 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
734 			 * arrived.
735 			 */
736 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
737 				continue;
738 			/*
739 			 * Look for a matching Initiator Node ACL in ASCII format
740 			 */
741 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
742 				continue;
743 
744 			kref_get(&deve_tmp->pr_kref);
745 			spin_unlock_bh(&port->sep_alua_lock);
746 			/*
747 			 * Grab a configfs group dependency that is released
748 			 * for the exception path at label out: below, or upon
749 			 * completion of adding ALL_TG_PT=1 registrations in
750 			 * __core_scsi3_add_registration()
751 			 */
752 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
753 			if (ret < 0) {
754 				pr_err("core_scsi3_lunacl_depend"
755 						"_item() failed\n");
756 				atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
757 				kref_put(&deve_tmp->pr_kref, target_pr_kref_release);
758 				goto out;
759 			}
760 			/*
761 			 * Located a matching SCSI Initiator Port on a different
762 			 * port, allocate the pr_reg_atp and attach it to the
763 			 * pr_reg->pr_reg_atp_list that will be processed once
764 			 * the original *pr_reg is processed in
765 			 * __core_scsi3_add_registration()
766 			 */
767 			lun_tmp = rcu_dereference_check(deve_tmp->se_lun,
768 				atomic_read(&deve_tmp->pr_kref.refcount) != 0);
769 
770 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
771 						nacl_tmp, lun_tmp, deve_tmp,
772 						deve_tmp->mapped_lun, NULL,
773 						sa_res_key, all_tg_pt, aptpl);
774 			if (!pr_reg_atp) {
775 				atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
776 				core_scsi3_lunacl_undepend_item(deve_tmp);
777 				goto out;
778 			}
779 
780 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
781 				      &pr_reg->pr_reg_atp_list);
782 			spin_lock_bh(&port->sep_alua_lock);
783 		}
784 		spin_unlock_bh(&port->sep_alua_lock);
785 
786 		spin_lock(&dev->se_port_lock);
787 		atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
788 	}
789 	spin_unlock(&dev->se_port_lock);
790 
791 	return pr_reg;
792 out:
793 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
794 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
795 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
796 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
797 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
798 	}
799 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
800 	return NULL;
801 }
802 
803 int core_scsi3_alloc_aptpl_registration(
804 	struct t10_reservation *pr_tmpl,
805 	u64 sa_res_key,
806 	unsigned char *i_port,
807 	unsigned char *isid,
808 	u32 mapped_lun,
809 	unsigned char *t_port,
810 	u16 tpgt,
811 	u32 target_lun,
812 	int res_holder,
813 	int all_tg_pt,
814 	u8 type)
815 {
816 	struct t10_pr_registration *pr_reg;
817 
818 	if (!i_port || !t_port || !sa_res_key) {
819 		pr_err("Illegal parameters for APTPL registration\n");
820 		return -EINVAL;
821 	}
822 
823 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
824 	if (!pr_reg) {
825 		pr_err("Unable to allocate struct t10_pr_registration\n");
826 		return -ENOMEM;
827 	}
828 
829 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
830 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
831 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
832 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
833 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
834 	atomic_set(&pr_reg->pr_res_holders, 0);
835 	pr_reg->pr_reg_nacl = NULL;
836 	pr_reg->pr_reg_deve = NULL;
837 	pr_reg->pr_res_mapped_lun = mapped_lun;
838 	pr_reg->pr_aptpl_target_lun = target_lun;
839 	pr_reg->pr_res_key = sa_res_key;
840 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
841 	pr_reg->pr_reg_aptpl = 1;
842 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
843 	pr_reg->pr_res_type = type;
844 	/*
845 	 * If an ISID value had been saved in APTPL metadata for this
846 	 * SCSI Initiator Port, restore it now.
847 	 */
848 	if (isid != NULL) {
849 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
850 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
851 		pr_reg->isid_present_at_reg = 1;
852 	}
853 	/*
854 	 * Copy the i_port and t_port information from caller.
855 	 */
856 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
857 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
858 	pr_reg->pr_reg_tpgt = tpgt;
859 	/*
860 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
861 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
862 	 * the Initiator Node LUN ACL from the fabric module is created for
863 	 * this registration.
864 	 */
865 	pr_reg->pr_res_holder = res_holder;
866 
867 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
868 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
869 			" metadata\n", (res_holder) ? "+reservation" : "");
870 	return 0;
871 }
872 
873 static void core_scsi3_aptpl_reserve(
874 	struct se_device *dev,
875 	struct se_portal_group *tpg,
876 	struct se_node_acl *node_acl,
877 	struct t10_pr_registration *pr_reg)
878 {
879 	char i_buf[PR_REG_ISID_ID_LEN];
880 
881 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
882 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
883 
884 	spin_lock(&dev->dev_reservation_lock);
885 	dev->dev_pr_res_holder = pr_reg;
886 	spin_unlock(&dev->dev_reservation_lock);
887 
888 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
889 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
890 		tpg->se_tpg_tfo->get_fabric_name(),
891 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
892 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
893 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
894 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
895 		i_buf);
896 }
897 
898 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
899 				struct t10_pr_registration *, enum register_type, int);
900 
901 static int __core_scsi3_check_aptpl_registration(
902 	struct se_device *dev,
903 	struct se_portal_group *tpg,
904 	struct se_lun *lun,
905 	u32 target_lun,
906 	struct se_node_acl *nacl,
907 	u32 mapped_lun)
908 {
909 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
910 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
911 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
912 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
913 	u16 tpgt;
914 
915 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
916 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
917 	/*
918 	 * Copy Initiator Port information from struct se_node_acl
919 	 */
920 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
921 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
922 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
923 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
924 	/*
925 	 * Look for the matching registrations+reservation from those
926 	 * created from APTPL metadata.  Note that multiple registrations
927 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
928 	 * TransportIDs.
929 	 */
930 	spin_lock(&pr_tmpl->aptpl_reg_lock);
931 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
932 				pr_reg_aptpl_list) {
933 
934 		if (!strcmp(pr_reg->pr_iport, i_port) &&
935 		     (pr_reg->pr_res_mapped_lun == mapped_lun) &&
936 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
937 		     (pr_reg->pr_reg_tpgt == tpgt) &&
938 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
939 
940 			pr_reg->pr_reg_nacl = nacl;
941 			pr_reg->tg_pt_sep_rtpi = lun->lun_sep->sep_rtpi;
942 
943 			list_del(&pr_reg->pr_reg_aptpl_list);
944 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
945 			/*
946 			 * At this point all of the pointers in *pr_reg will
947 			 * be setup, so go ahead and add the registration.
948 			 */
949 
950 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
951 			/*
952 			 * If this registration is the reservation holder,
953 			 * make that happen now..
954 			 */
955 			if (pr_reg->pr_res_holder)
956 				core_scsi3_aptpl_reserve(dev, tpg,
957 						nacl, pr_reg);
958 			/*
959 			 * Reenable pr_aptpl_active to accept new metadata
960 			 * updates once the SCSI device is active again..
961 			 */
962 			spin_lock(&pr_tmpl->aptpl_reg_lock);
963 			pr_tmpl->pr_aptpl_active = 1;
964 		}
965 	}
966 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
967 
968 	return 0;
969 }
970 
971 int core_scsi3_check_aptpl_registration(
972 	struct se_device *dev,
973 	struct se_portal_group *tpg,
974 	struct se_lun *lun,
975 	struct se_node_acl *nacl,
976 	u32 mapped_lun)
977 {
978 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
979 		return 0;
980 
981 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
982 						     lun->unpacked_lun, nacl,
983 						     mapped_lun);
984 }
985 
986 static void __core_scsi3_dump_registration(
987 	const struct target_core_fabric_ops *tfo,
988 	struct se_device *dev,
989 	struct se_node_acl *nacl,
990 	struct t10_pr_registration *pr_reg,
991 	enum register_type register_type)
992 {
993 	struct se_portal_group *se_tpg = nacl->se_tpg;
994 	char i_buf[PR_REG_ISID_ID_LEN];
995 
996 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
997 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
998 
999 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1000 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == REGISTER_AND_MOVE) ?
1001 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
1002 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1003 		i_buf);
1004 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1005 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
1006 		tfo->tpg_get_tag(se_tpg));
1007 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1008 		" Port(s)\n",  tfo->get_fabric_name(),
1009 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1010 		dev->transport->name);
1011 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1012 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
1013 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1014 		pr_reg->pr_reg_aptpl);
1015 }
1016 
1017 static void __core_scsi3_add_registration(
1018 	struct se_device *dev,
1019 	struct se_node_acl *nacl,
1020 	struct t10_pr_registration *pr_reg,
1021 	enum register_type register_type,
1022 	int register_move)
1023 {
1024 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1025 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1026 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1027 	struct se_dev_entry *deve;
1028 
1029 	/*
1030 	 * Increment PRgeneration counter for struct se_device upon a successful
1031 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1032 	 *
1033 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1034 	 * action, the struct se_device->dev_reservation_lock will already be held,
1035 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1036 	 * for the REGISTER.
1037 	 */
1038 	pr_reg->pr_res_generation = (register_move) ?
1039 			dev->t10_pr.pr_generation++ :
1040 			core_scsi3_pr_generation(dev);
1041 
1042 	spin_lock(&pr_tmpl->registration_lock);
1043 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1044 
1045 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1046 	spin_unlock(&pr_tmpl->registration_lock);
1047 
1048 	rcu_read_lock();
1049 	deve = pr_reg->pr_reg_deve;
1050 	if (deve)
1051 		set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1052 	rcu_read_unlock();
1053 
1054 	/*
1055 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1056 	 */
1057 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1058 		return;
1059 	/*
1060 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1061 	 * allocated in __core_scsi3_alloc_registration()
1062 	 */
1063 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1064 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1065 		struct se_node_acl *nacl_tmp = pr_reg_tmp->pr_reg_nacl;
1066 
1067 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1068 
1069 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1070 
1071 		spin_lock(&pr_tmpl->registration_lock);
1072 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1073 			      &pr_tmpl->registration_list);
1074 
1075 		__core_scsi3_dump_registration(tfo, dev, nacl_tmp, pr_reg_tmp,
1076 					       register_type);
1077 		spin_unlock(&pr_tmpl->registration_lock);
1078 
1079 		rcu_read_lock();
1080 		deve = pr_reg_tmp->pr_reg_deve;
1081 		if (deve)
1082 			set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1083 		rcu_read_unlock();
1084 
1085 		/*
1086 		 * Drop configfs group dependency reference from
1087 		 * __core_scsi3_alloc_registration()
1088 		 */
1089 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1090 	}
1091 }
1092 
1093 static int core_scsi3_alloc_registration(
1094 	struct se_device *dev,
1095 	struct se_node_acl *nacl,
1096 	struct se_lun *lun,
1097 	struct se_dev_entry *deve,
1098 	u32 mapped_lun,
1099 	unsigned char *isid,
1100 	u64 sa_res_key,
1101 	int all_tg_pt,
1102 	int aptpl,
1103 	enum register_type register_type,
1104 	int register_move)
1105 {
1106 	struct t10_pr_registration *pr_reg;
1107 
1108 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, lun, deve, mapped_lun,
1109 						 isid, sa_res_key, all_tg_pt,
1110 						 aptpl);
1111 	if (!pr_reg)
1112 		return -EPERM;
1113 
1114 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1115 			register_type, register_move);
1116 	return 0;
1117 }
1118 
1119 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1120 	struct se_device *dev,
1121 	struct se_node_acl *nacl,
1122 	unsigned char *isid)
1123 {
1124 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1125 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1126 	struct se_portal_group *tpg;
1127 
1128 	spin_lock(&pr_tmpl->registration_lock);
1129 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1130 			&pr_tmpl->registration_list, pr_reg_list) {
1131 		/*
1132 		 * First look for a matching struct se_node_acl
1133 		 */
1134 		if (pr_reg->pr_reg_nacl != nacl)
1135 			continue;
1136 
1137 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1138 		/*
1139 		 * If this registration does NOT contain a fabric provided
1140 		 * ISID, then we have found a match.
1141 		 */
1142 		if (!pr_reg->isid_present_at_reg) {
1143 			/*
1144 			 * Determine if this SCSI device server requires that
1145 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1146 			 * for fabric modules (iSCSI) requiring them.
1147 			 */
1148 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1149 				if (dev->dev_attrib.enforce_pr_isids)
1150 					continue;
1151 			}
1152 			atomic_inc_mb(&pr_reg->pr_res_holders);
1153 			spin_unlock(&pr_tmpl->registration_lock);
1154 			return pr_reg;
1155 		}
1156 		/*
1157 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1158 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1159 		 * matching ISID to be provided by the local SCSI Initiator Port.
1160 		 */
1161 		if (!isid)
1162 			continue;
1163 		if (strcmp(isid, pr_reg->pr_reg_isid))
1164 			continue;
1165 
1166 		atomic_inc_mb(&pr_reg->pr_res_holders);
1167 		spin_unlock(&pr_tmpl->registration_lock);
1168 		return pr_reg;
1169 	}
1170 	spin_unlock(&pr_tmpl->registration_lock);
1171 
1172 	return NULL;
1173 }
1174 
1175 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1176 	struct se_device *dev,
1177 	struct se_node_acl *nacl,
1178 	struct se_session *sess)
1179 {
1180 	struct se_portal_group *tpg = nacl->se_tpg;
1181 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1182 
1183 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1184 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1185 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1186 					PR_REG_ISID_LEN);
1187 		isid_ptr = &buf[0];
1188 	}
1189 
1190 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1191 }
1192 
1193 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1194 {
1195 	atomic_dec_mb(&pr_reg->pr_res_holders);
1196 }
1197 
1198 static int core_scsi3_check_implicit_release(
1199 	struct se_device *dev,
1200 	struct t10_pr_registration *pr_reg)
1201 {
1202 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1203 	struct t10_pr_registration *pr_res_holder;
1204 	int ret = 0;
1205 
1206 	spin_lock(&dev->dev_reservation_lock);
1207 	pr_res_holder = dev->dev_pr_res_holder;
1208 	if (!pr_res_holder) {
1209 		spin_unlock(&dev->dev_reservation_lock);
1210 		return ret;
1211 	}
1212 	if (pr_res_holder == pr_reg) {
1213 		/*
1214 		 * Perform an implicit RELEASE if the registration that
1215 		 * is being released is holding the reservation.
1216 		 *
1217 		 * From spc4r17, section 5.7.11.1:
1218 		 *
1219 		 * e) If the I_T nexus is the persistent reservation holder
1220 		 *    and the persistent reservation is not an all registrants
1221 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1222 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1223 		 *    service action with the SERVICE ACTION RESERVATION KEY
1224 		 *    field set to zero (see 5.7.11.3).
1225 		 */
1226 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1227 		ret = 1;
1228 		/*
1229 		 * For 'All Registrants' reservation types, all existing
1230 		 * registrations are still processed as reservation holders
1231 		 * in core_scsi3_pr_seq_non_holder() after the initial
1232 		 * reservation holder is implicitly released here.
1233 		 */
1234 	} else if (pr_reg->pr_reg_all_tg_pt &&
1235 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1236 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1237 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1238 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1239 			" UNREGISTER while existing reservation with matching"
1240 			" key 0x%016Lx is present from another SCSI Initiator"
1241 			" Port\n", pr_reg->pr_res_key);
1242 		ret = -EPERM;
1243 	}
1244 	spin_unlock(&dev->dev_reservation_lock);
1245 
1246 	return ret;
1247 }
1248 
1249 /*
1250  * Called with struct t10_reservation->registration_lock held.
1251  */
1252 static void __core_scsi3_free_registration(
1253 	struct se_device *dev,
1254 	struct t10_pr_registration *pr_reg,
1255 	struct list_head *preempt_and_abort_list,
1256 	int dec_holders)
1257 	__releases(&pr_tmpl->registration_lock)
1258 	__acquires(&pr_tmpl->registration_lock)
1259 {
1260 	const struct target_core_fabric_ops *tfo =
1261 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1262 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1263 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1264 	struct se_dev_entry *deve;
1265 	char i_buf[PR_REG_ISID_ID_LEN];
1266 
1267 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1268 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1269 
1270 	if (!list_empty(&pr_reg->pr_reg_list))
1271 		list_del(&pr_reg->pr_reg_list);
1272 	/*
1273 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1274 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1275 	 */
1276 	if (dec_holders)
1277 		core_scsi3_put_pr_reg(pr_reg);
1278 
1279 	spin_unlock(&pr_tmpl->registration_lock);
1280 	/*
1281 	 * Wait until all reference from any other I_T nexuses for this
1282 	 * *pr_reg have been released.  Because list_del() is called above,
1283 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1284 	 * count back to zero, and we release *pr_reg.
1285 	 */
1286 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1287 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1288 				tfo->get_fabric_name());
1289 		cpu_relax();
1290 	}
1291 
1292 	rcu_read_lock();
1293 	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
1294 	if (deve)
1295 		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1296 	rcu_read_unlock();
1297 
1298 	spin_lock(&pr_tmpl->registration_lock);
1299 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1300 		" Node: %s%s\n", tfo->get_fabric_name(),
1301 		pr_reg->pr_reg_nacl->initiatorname,
1302 		i_buf);
1303 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1304 		" Port(s)\n", tfo->get_fabric_name(),
1305 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1306 		dev->transport->name);
1307 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1308 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1309 		pr_reg->pr_res_generation);
1310 
1311 	if (!preempt_and_abort_list) {
1312 		pr_reg->pr_reg_deve = NULL;
1313 		pr_reg->pr_reg_nacl = NULL;
1314 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1315 		return;
1316 	}
1317 	/*
1318 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1319 	 * are released once the ABORT_TASK_SET has completed..
1320 	 */
1321 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1322 }
1323 
1324 void core_scsi3_free_pr_reg_from_nacl(
1325 	struct se_device *dev,
1326 	struct se_node_acl *nacl)
1327 {
1328 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1329 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1330 	bool free_reg = false;
1331 	/*
1332 	 * If the passed se_node_acl matches the reservation holder,
1333 	 * release the reservation.
1334 	 */
1335 	spin_lock(&dev->dev_reservation_lock);
1336 	pr_res_holder = dev->dev_pr_res_holder;
1337 	if ((pr_res_holder != NULL) &&
1338 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1339 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1340 		free_reg = true;
1341 	}
1342 	spin_unlock(&dev->dev_reservation_lock);
1343 	/*
1344 	 * Release any registration associated with the struct se_node_acl.
1345 	 */
1346 	spin_lock(&pr_tmpl->registration_lock);
1347 	if (pr_res_holder && free_reg)
1348 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1349 
1350 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1351 			&pr_tmpl->registration_list, pr_reg_list) {
1352 
1353 		if (pr_reg->pr_reg_nacl != nacl)
1354 			continue;
1355 
1356 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1357 	}
1358 	spin_unlock(&pr_tmpl->registration_lock);
1359 }
1360 
1361 void core_scsi3_free_all_registrations(
1362 	struct se_device *dev)
1363 {
1364 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1365 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1366 
1367 	spin_lock(&dev->dev_reservation_lock);
1368 	pr_res_holder = dev->dev_pr_res_holder;
1369 	if (pr_res_holder != NULL) {
1370 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1371 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1372 						  pr_res_holder, 0, 0);
1373 	}
1374 	spin_unlock(&dev->dev_reservation_lock);
1375 
1376 	spin_lock(&pr_tmpl->registration_lock);
1377 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1378 			&pr_tmpl->registration_list, pr_reg_list) {
1379 
1380 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1381 	}
1382 	spin_unlock(&pr_tmpl->registration_lock);
1383 
1384 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1385 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1386 				pr_reg_aptpl_list) {
1387 		list_del(&pr_reg->pr_reg_aptpl_list);
1388 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1389 	}
1390 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1391 }
1392 
1393 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1394 {
1395 	return target_depend_item(&tpg->tpg_group.cg_item);
1396 }
1397 
1398 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1399 {
1400 	target_undepend_item(&tpg->tpg_group.cg_item);
1401 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1402 }
1403 
1404 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1405 {
1406 	if (nacl->dynamic_node_acl)
1407 		return 0;
1408 	return target_depend_item(&nacl->acl_group.cg_item);
1409 }
1410 
1411 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1412 {
1413 	if (!nacl->dynamic_node_acl)
1414 		target_undepend_item(&nacl->acl_group.cg_item);
1415 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1416 }
1417 
1418 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1419 {
1420 	struct se_lun_acl *lun_acl;
1421 	struct se_node_acl *nacl;
1422 	struct se_portal_group *tpg;
1423 	/*
1424 	 * For nacl->dynamic_node_acl=1
1425 	 */
1426 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1427 				atomic_read(&se_deve->pr_kref.refcount) != 0);
1428 	if (!lun_acl)
1429 		return 0;
1430 
1431 	nacl = lun_acl->se_lun_nacl;
1432 	tpg = nacl->se_tpg;
1433 
1434 	return target_depend_item(&lun_acl->se_lun_group.cg_item);
1435 }
1436 
1437 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1438 {
1439 	struct se_lun_acl *lun_acl;
1440 	struct se_node_acl *nacl;
1441 	struct se_portal_group *tpg;
1442 	/*
1443 	 * For nacl->dynamic_node_acl=1
1444 	 */
1445 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1446 				atomic_read(&se_deve->pr_kref.refcount) != 0);
1447 	if (!lun_acl) {
1448 		kref_put(&se_deve->pr_kref, target_pr_kref_release);
1449 		return;
1450 	}
1451 	nacl = lun_acl->se_lun_nacl;
1452 	tpg = nacl->se_tpg;
1453 
1454 	target_undepend_item(&lun_acl->se_lun_group.cg_item);
1455 	kref_put(&se_deve->pr_kref, target_pr_kref_release);
1456 }
1457 
1458 static sense_reason_t
1459 core_scsi3_decode_spec_i_port(
1460 	struct se_cmd *cmd,
1461 	struct se_portal_group *tpg,
1462 	unsigned char *l_isid,
1463 	u64 sa_res_key,
1464 	int all_tg_pt,
1465 	int aptpl)
1466 {
1467 	struct se_device *dev = cmd->se_dev;
1468 	struct se_port *tmp_port;
1469 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1470 	struct se_session *se_sess = cmd->se_sess;
1471 	struct se_node_acl *dest_node_acl = NULL;
1472 	struct se_dev_entry *dest_se_deve = NULL;
1473 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1474 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1475 	LIST_HEAD(tid_dest_list);
1476 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1477 	unsigned char *buf, *ptr, proto_ident;
1478 	const unsigned char *i_str;
1479 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1480 	sense_reason_t ret;
1481 	u32 tpdl, tid_len = 0;
1482 	u32 dest_rtpi = 0;
1483 
1484 	/*
1485 	 * Allocate a struct pr_transport_id_holder and setup the
1486 	 * local_node_acl pointer and add to struct list_head tid_dest_list
1487 	 * for add registration processing in the loop of tid_dest_list below.
1488 	 */
1489 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1490 	if (!tidh_new) {
1491 		pr_err("Unable to allocate tidh_new\n");
1492 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1493 	}
1494 	INIT_LIST_HEAD(&tidh_new->dest_list);
1495 	tidh_new->dest_tpg = tpg;
1496 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1497 
1498 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1499 				se_sess->se_node_acl, cmd->se_lun,
1500 				NULL, cmd->orig_fe_lun, l_isid,
1501 				sa_res_key, all_tg_pt, aptpl);
1502 	if (!local_pr_reg) {
1503 		kfree(tidh_new);
1504 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1505 	}
1506 	tidh_new->dest_pr_reg = local_pr_reg;
1507 	/*
1508 	 * The local I_T nexus does not hold any configfs dependances,
1509 	 * so we set tidh_new->dest_se_deve to NULL to prevent the
1510 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1511 	 */
1512 	tidh_new->dest_se_deve = NULL;
1513 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1514 
1515 	if (cmd->data_length < 28) {
1516 		pr_warn("SPC-PR: Received PR OUT parameter list"
1517 			" length too small: %u\n", cmd->data_length);
1518 		ret = TCM_INVALID_PARAMETER_LIST;
1519 		goto out;
1520 	}
1521 
1522 	buf = transport_kmap_data_sg(cmd);
1523 	if (!buf) {
1524 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1525 		goto out;
1526 	}
1527 
1528 	/*
1529 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1530 	 * first extract TransportID Parameter Data Length, and make sure
1531 	 * the value matches up to the SCSI expected data transfer length.
1532 	 */
1533 	tpdl = (buf[24] & 0xff) << 24;
1534 	tpdl |= (buf[25] & 0xff) << 16;
1535 	tpdl |= (buf[26] & 0xff) << 8;
1536 	tpdl |= buf[27] & 0xff;
1537 
1538 	if ((tpdl + 28) != cmd->data_length) {
1539 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1540 			" does not equal CDB data_length: %u\n", tpdl,
1541 			cmd->data_length);
1542 		ret = TCM_INVALID_PARAMETER_LIST;
1543 		goto out_unmap;
1544 	}
1545 	/*
1546 	 * Start processing the received transport IDs using the
1547 	 * receiving I_T Nexus portal's fabric dependent methods to
1548 	 * obtain the SCSI Initiator Port/Device Identifiers.
1549 	 */
1550 	ptr = &buf[28];
1551 
1552 	while (tpdl > 0) {
1553 		struct se_lun *dest_lun;
1554 
1555 		proto_ident = (ptr[0] & 0x0f);
1556 		dest_tpg = NULL;
1557 
1558 		spin_lock(&dev->se_port_lock);
1559 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1560 			tmp_tpg = tmp_port->sep_tpg;
1561 			if (!tmp_tpg)
1562 				continue;
1563 
1564 			/*
1565 			 * Look for the matching proto_ident provided by
1566 			 * the received TransportID
1567 			 */
1568 			if (tmp_tpg->proto_id != proto_ident)
1569 				continue;
1570 			dest_rtpi = tmp_port->sep_rtpi;
1571 
1572 			i_str = target_parse_pr_out_transport_id(tmp_tpg,
1573 					(const char *)ptr, &tid_len, &iport_ptr);
1574 			if (!i_str)
1575 				continue;
1576 
1577 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1578 			spin_unlock(&dev->se_port_lock);
1579 
1580 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1581 				pr_err(" core_scsi3_tpg_depend_item()"
1582 					" for tmp_tpg\n");
1583 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1584 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1585 				goto out_unmap;
1586 			}
1587 			/*
1588 			 * Locate the destination initiator ACL to be registered
1589 			 * from the decoded fabric module specific TransportID
1590 			 * at *i_str.
1591 			 */
1592 			mutex_lock(&tmp_tpg->acl_node_mutex);
1593 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1594 						tmp_tpg, i_str);
1595 			if (dest_node_acl)
1596 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1597 			mutex_unlock(&tmp_tpg->acl_node_mutex);
1598 
1599 			if (!dest_node_acl) {
1600 				core_scsi3_tpg_undepend_item(tmp_tpg);
1601 				spin_lock(&dev->se_port_lock);
1602 				continue;
1603 			}
1604 
1605 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1606 				pr_err("configfs_depend_item() failed"
1607 					" for dest_node_acl->acl_group\n");
1608 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1609 				core_scsi3_tpg_undepend_item(tmp_tpg);
1610 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1611 				goto out_unmap;
1612 			}
1613 
1614 			dest_tpg = tmp_tpg;
1615 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1616 				" %s Port RTPI: %hu\n",
1617 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1618 				dest_node_acl->initiatorname, dest_rtpi);
1619 
1620 			spin_lock(&dev->se_port_lock);
1621 			break;
1622 		}
1623 		spin_unlock(&dev->se_port_lock);
1624 
1625 		if (!dest_tpg) {
1626 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1627 					" dest_tpg\n");
1628 			ret = TCM_INVALID_PARAMETER_LIST;
1629 			goto out_unmap;
1630 		}
1631 
1632 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1633 			" tid_len: %d for %s + %s\n",
1634 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1635 			tpdl, tid_len, i_str, iport_ptr);
1636 
1637 		if (tid_len > tpdl) {
1638 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1639 				" %u for Transport ID: %s\n", tid_len, ptr);
1640 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1641 			core_scsi3_tpg_undepend_item(dest_tpg);
1642 			ret = TCM_INVALID_PARAMETER_LIST;
1643 			goto out_unmap;
1644 		}
1645 		/*
1646 		 * Locate the desintation struct se_dev_entry pointer for matching
1647 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1648 		 * Target Port.
1649 		 */
1650 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1651 					dest_rtpi);
1652 		if (!dest_se_deve) {
1653 			pr_err("Unable to locate %s dest_se_deve"
1654 				" from destination RTPI: %hu\n",
1655 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1656 				dest_rtpi);
1657 
1658 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1659 			core_scsi3_tpg_undepend_item(dest_tpg);
1660 			ret = TCM_INVALID_PARAMETER_LIST;
1661 			goto out_unmap;
1662 		}
1663 
1664 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1665 			pr_err("core_scsi3_lunacl_depend_item()"
1666 					" failed\n");
1667 			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
1668 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1669 			core_scsi3_tpg_undepend_item(dest_tpg);
1670 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1671 			goto out_unmap;
1672 		}
1673 
1674 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1675 			" dest_se_deve mapped_lun: %u\n",
1676 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1677 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1678 
1679 		/*
1680 		 * Skip any TransportIDs that already have a registration for
1681 		 * this target port.
1682 		 */
1683 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1684 					iport_ptr);
1685 		if (pr_reg_e) {
1686 			core_scsi3_put_pr_reg(pr_reg_e);
1687 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1688 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1689 			core_scsi3_tpg_undepend_item(dest_tpg);
1690 			ptr += tid_len;
1691 			tpdl -= tid_len;
1692 			tid_len = 0;
1693 			continue;
1694 		}
1695 		/*
1696 		 * Allocate a struct pr_transport_id_holder and setup
1697 		 * the dest_node_acl and dest_se_deve pointers for the
1698 		 * loop below.
1699 		 */
1700 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1701 				GFP_KERNEL);
1702 		if (!tidh_new) {
1703 			pr_err("Unable to allocate tidh_new\n");
1704 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1705 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1706 			core_scsi3_tpg_undepend_item(dest_tpg);
1707 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1708 			goto out_unmap;
1709 		}
1710 		INIT_LIST_HEAD(&tidh_new->dest_list);
1711 		tidh_new->dest_tpg = dest_tpg;
1712 		tidh_new->dest_node_acl = dest_node_acl;
1713 		tidh_new->dest_se_deve = dest_se_deve;
1714 
1715 		/*
1716 		 * Allocate, but do NOT add the registration for the
1717 		 * TransportID referenced SCSI Initiator port.  This
1718 		 * done because of the following from spc4r17 in section
1719 		 * 6.14.3 wrt SPEC_I_PT:
1720 		 *
1721 		 * "If a registration fails for any initiator port (e.g., if th
1722 		 * logical unit does not have enough resources available to
1723 		 * hold the registration information), no registrations shall be
1724 		 * made, and the command shall be terminated with
1725 		 * CHECK CONDITION status."
1726 		 *
1727 		 * That means we call __core_scsi3_alloc_registration() here,
1728 		 * and then call __core_scsi3_add_registration() in the
1729 		 * 2nd loop which will never fail.
1730 		 */
1731 		dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
1732 				atomic_read(&dest_se_deve->pr_kref.refcount) != 0);
1733 
1734 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1735 					dest_node_acl, dest_lun, dest_se_deve,
1736 					dest_se_deve->mapped_lun, iport_ptr,
1737 					sa_res_key, all_tg_pt, aptpl);
1738 		if (!dest_pr_reg) {
1739 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1740 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1741 			core_scsi3_tpg_undepend_item(dest_tpg);
1742 			kfree(tidh_new);
1743 			ret = TCM_INVALID_PARAMETER_LIST;
1744 			goto out_unmap;
1745 		}
1746 		tidh_new->dest_pr_reg = dest_pr_reg;
1747 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1748 
1749 		ptr += tid_len;
1750 		tpdl -= tid_len;
1751 		tid_len = 0;
1752 
1753 	}
1754 
1755 	transport_kunmap_data_sg(cmd);
1756 
1757 	/*
1758 	 * Go ahead and create a registrations from tid_dest_list for the
1759 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1760 	 * and dest_se_deve.
1761 	 *
1762 	 * The SA Reservation Key from the PROUT is set for the
1763 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1764 	 * means that the TransportID Initiator port will be
1765 	 * registered on all of the target ports in the SCSI target device
1766 	 * ALL_TG_PT=0 means the registration will only be for the
1767 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1768 	 * was received.
1769 	 */
1770 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1771 		dest_tpg = tidh->dest_tpg;
1772 		dest_node_acl = tidh->dest_node_acl;
1773 		dest_se_deve = tidh->dest_se_deve;
1774 		dest_pr_reg = tidh->dest_pr_reg;
1775 
1776 		list_del(&tidh->dest_list);
1777 		kfree(tidh);
1778 
1779 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1780 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1781 
1782 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1783 					dest_pr_reg, 0, 0);
1784 
1785 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1786 			" registered Transport ID for Node: %s%s Mapped LUN:"
1787 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1788 			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
1789 			dest_se_deve->mapped_lun : 0);
1790 
1791 		if (!dest_se_deve)
1792 			continue;
1793 
1794 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1795 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1796 		core_scsi3_tpg_undepend_item(dest_tpg);
1797 	}
1798 
1799 	return 0;
1800 out_unmap:
1801 	transport_kunmap_data_sg(cmd);
1802 out:
1803 	/*
1804 	 * For the failure case, release everything from tid_dest_list
1805 	 * including *dest_pr_reg and the configfs dependances..
1806 	 */
1807 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1808 		dest_tpg = tidh->dest_tpg;
1809 		dest_node_acl = tidh->dest_node_acl;
1810 		dest_se_deve = tidh->dest_se_deve;
1811 		dest_pr_reg = tidh->dest_pr_reg;
1812 
1813 		list_del(&tidh->dest_list);
1814 		kfree(tidh);
1815 		/*
1816 		 * Release any extra ALL_TG_PT=1 registrations for
1817 		 * the SPEC_I_PT=1 case.
1818 		 */
1819 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1820 				&dest_pr_reg->pr_reg_atp_list,
1821 				pr_reg_atp_mem_list) {
1822 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1823 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1824 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1825 		}
1826 
1827 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1828 
1829 		if (!dest_se_deve)
1830 			continue;
1831 
1832 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1833 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1834 		core_scsi3_tpg_undepend_item(dest_tpg);
1835 	}
1836 	return ret;
1837 }
1838 
1839 static int core_scsi3_update_aptpl_buf(
1840 	struct se_device *dev,
1841 	unsigned char *buf,
1842 	u32 pr_aptpl_buf_len)
1843 {
1844 	struct se_portal_group *tpg;
1845 	struct t10_pr_registration *pr_reg;
1846 	unsigned char tmp[512], isid_buf[32];
1847 	ssize_t len = 0;
1848 	int reg_count = 0;
1849 	int ret = 0;
1850 
1851 	spin_lock(&dev->dev_reservation_lock);
1852 	spin_lock(&dev->t10_pr.registration_lock);
1853 	/*
1854 	 * Walk the registration list..
1855 	 */
1856 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1857 			pr_reg_list) {
1858 
1859 		tmp[0] = '\0';
1860 		isid_buf[0] = '\0';
1861 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1862 		/*
1863 		 * Write out any ISID value to APTPL metadata that was included
1864 		 * in the original registration.
1865 		 */
1866 		if (pr_reg->isid_present_at_reg)
1867 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1868 					pr_reg->pr_reg_isid);
1869 		/*
1870 		 * Include special metadata if the pr_reg matches the
1871 		 * reservation holder.
1872 		 */
1873 		if (dev->dev_pr_res_holder == pr_reg) {
1874 			snprintf(tmp, 512, "PR_REG_START: %d"
1875 				"\ninitiator_fabric=%s\n"
1876 				"initiator_node=%s\n%s"
1877 				"sa_res_key=%llu\n"
1878 				"res_holder=1\nres_type=%02x\n"
1879 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1880 				"mapped_lun=%u\n", reg_count,
1881 				tpg->se_tpg_tfo->get_fabric_name(),
1882 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1883 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1884 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1885 				pr_reg->pr_res_mapped_lun);
1886 		} else {
1887 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1888 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1889 				"sa_res_key=%llu\nres_holder=0\n"
1890 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1891 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1892 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1893 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1894 				pr_reg->pr_res_mapped_lun);
1895 		}
1896 
1897 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1898 			pr_err("Unable to update renaming APTPL metadata,"
1899 			       " reallocating larger buffer\n");
1900 			ret = -EMSGSIZE;
1901 			goto out;
1902 		}
1903 		len += sprintf(buf+len, "%s", tmp);
1904 
1905 		/*
1906 		 * Include information about the associated SCSI target port.
1907 		 */
1908 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1909 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1910 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1911 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1912 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1913 			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
1914 			reg_count);
1915 
1916 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1917 			pr_err("Unable to update renaming APTPL metadata,"
1918 			       " reallocating larger buffer\n");
1919 			ret = -EMSGSIZE;
1920 			goto out;
1921 		}
1922 		len += sprintf(buf+len, "%s", tmp);
1923 		reg_count++;
1924 	}
1925 
1926 	if (!reg_count)
1927 		len += sprintf(buf+len, "No Registrations or Reservations");
1928 
1929 out:
1930 	spin_unlock(&dev->t10_pr.registration_lock);
1931 	spin_unlock(&dev->dev_reservation_lock);
1932 
1933 	return ret;
1934 }
1935 
1936 static int __core_scsi3_write_aptpl_to_file(
1937 	struct se_device *dev,
1938 	unsigned char *buf)
1939 {
1940 	struct t10_wwn *wwn = &dev->t10_wwn;
1941 	struct file *file;
1942 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1943 	char path[512];
1944 	u32 pr_aptpl_buf_len;
1945 	int ret;
1946 
1947 	memset(path, 0, 512);
1948 
1949 	if (strlen(&wwn->unit_serial[0]) >= 512) {
1950 		pr_err("WWN value for struct se_device does not fit"
1951 			" into path buffer\n");
1952 		return -EMSGSIZE;
1953 	}
1954 
1955 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
1956 	file = filp_open(path, flags, 0600);
1957 	if (IS_ERR(file)) {
1958 		pr_err("filp_open(%s) for APTPL metadata"
1959 			" failed\n", path);
1960 		return PTR_ERR(file);
1961 	}
1962 
1963 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1964 
1965 	ret = kernel_write(file, buf, pr_aptpl_buf_len, 0);
1966 
1967 	if (ret < 0)
1968 		pr_debug("Error writing APTPL metadata file: %s\n", path);
1969 	fput(file);
1970 
1971 	return (ret < 0) ? -EIO : 0;
1972 }
1973 
1974 /*
1975  * Clear the APTPL metadata if APTPL has been disabled, otherwise
1976  * write out the updated metadata to struct file for this SCSI device.
1977  */
1978 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
1979 {
1980 	unsigned char *buf;
1981 	int rc, len = PR_APTPL_BUF_LEN;
1982 
1983 	if (!aptpl) {
1984 		char *null_buf = "No Registrations or Reservations\n";
1985 
1986 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
1987 		dev->t10_pr.pr_aptpl_active = 0;
1988 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
1989 
1990 		if (rc)
1991 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1992 
1993 		return 0;
1994 	}
1995 retry:
1996 	buf = vzalloc(len);
1997 	if (!buf)
1998 		return TCM_OUT_OF_RESOURCES;
1999 
2000 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
2001 	if (rc < 0) {
2002 		vfree(buf);
2003 		len *= 2;
2004 		goto retry;
2005 	}
2006 
2007 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2008 	if (rc != 0) {
2009 		pr_err("SPC-3 PR: Could not update APTPL\n");
2010 		vfree(buf);
2011 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2012 	}
2013 	dev->t10_pr.pr_aptpl_active = 1;
2014 	vfree(buf);
2015 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2016 	return 0;
2017 }
2018 
2019 static sense_reason_t
2020 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2021 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2022 {
2023 	struct se_session *se_sess = cmd->se_sess;
2024 	struct se_device *dev = cmd->se_dev;
2025 	struct se_lun *se_lun = cmd->se_lun;
2026 	struct se_portal_group *se_tpg;
2027 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2028 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2029 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2030 	sense_reason_t ret = TCM_NO_SENSE;
2031 	int pr_holder = 0, type;
2032 
2033 	if (!se_sess || !se_lun) {
2034 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2035 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2036 	}
2037 	se_tpg = se_sess->se_tpg;
2038 
2039 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2040 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2041 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2042 				PR_REG_ISID_LEN);
2043 		isid_ptr = &isid_buf[0];
2044 	}
2045 	/*
2046 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2047 	 */
2048 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2049 	if (!pr_reg) {
2050 		if (res_key) {
2051 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2052 				" for SA REGISTER, returning CONFLICT\n");
2053 			return TCM_RESERVATION_CONFLICT;
2054 		}
2055 		/*
2056 		 * Do nothing but return GOOD status.
2057 		 */
2058 		if (!sa_res_key)
2059 			return 0;
2060 
2061 		if (!spec_i_pt) {
2062 			/*
2063 			 * Perform the Service Action REGISTER on the Initiator
2064 			 * Port Endpoint that the PRO was received from on the
2065 			 * Logical Unit of the SCSI device server.
2066 			 */
2067 			if (core_scsi3_alloc_registration(cmd->se_dev,
2068 					se_sess->se_node_acl, cmd->se_lun,
2069 					NULL, cmd->orig_fe_lun, isid_ptr,
2070 					sa_res_key, all_tg_pt, aptpl,
2071 					register_type, 0)) {
2072 				pr_err("Unable to allocate"
2073 					" struct t10_pr_registration\n");
2074 				return TCM_INVALID_PARAMETER_LIST;
2075 			}
2076 		} else {
2077 			/*
2078 			 * Register both the Initiator port that received
2079 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2080 			 * TransportID from Parameter list and loop through
2081 			 * fabric dependent parameter list while calling
2082 			 * logic from of core_scsi3_alloc_registration() for
2083 			 * each TransportID provided SCSI Initiator Port/Device
2084 			 */
2085 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2086 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2087 			if (ret != 0)
2088 				return ret;
2089 		}
2090 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2091 	}
2092 
2093 	/* ok, existing registration */
2094 
2095 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2096 		pr_err("SPC-3 PR REGISTER: Received"
2097 		       " res_key: 0x%016Lx does not match"
2098 		       " existing SA REGISTER res_key:"
2099 		       " 0x%016Lx\n", res_key,
2100 		       pr_reg->pr_res_key);
2101 		ret = TCM_RESERVATION_CONFLICT;
2102 		goto out;
2103 	}
2104 
2105 	if (spec_i_pt) {
2106 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2107 			" set on a registered nexus\n");
2108 		ret = TCM_INVALID_PARAMETER_LIST;
2109 		goto out;
2110 	}
2111 
2112 	/*
2113 	 * An existing ALL_TG_PT=1 registration being released
2114 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2115 	 */
2116 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2117 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2118 			" registration exists, but ALL_TG_PT=1 bit not"
2119 			" present in received PROUT\n");
2120 		ret = TCM_INVALID_CDB_FIELD;
2121 		goto out;
2122 	}
2123 
2124 	/*
2125 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2126 	 */
2127 	if (sa_res_key) {
2128 		/*
2129 		 * Increment PRgeneration counter for struct se_device"
2130 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2131 		 * READ_KEYS service action.
2132 		 */
2133 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2134 		pr_reg->pr_res_key = sa_res_key;
2135 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2136 			 " Key for %s to: 0x%016Lx PRgeneration:"
2137 			 " 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2138 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2139 			 pr_reg->pr_reg_nacl->initiatorname,
2140 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2141 
2142 	} else {
2143 		/*
2144 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2145 		 */
2146 		type = pr_reg->pr_res_type;
2147 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2148 							      pr_reg);
2149 		if (pr_holder < 0) {
2150 			ret = TCM_RESERVATION_CONFLICT;
2151 			goto out;
2152 		}
2153 
2154 		spin_lock(&pr_tmpl->registration_lock);
2155 		/*
2156 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2157 		 * and matching pr_res_key.
2158 		 */
2159 		if (pr_reg->pr_reg_all_tg_pt) {
2160 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2161 					&pr_tmpl->registration_list,
2162 					pr_reg_list) {
2163 
2164 				if (!pr_reg_p->pr_reg_all_tg_pt)
2165 					continue;
2166 				if (pr_reg_p->pr_res_key != res_key)
2167 					continue;
2168 				if (pr_reg == pr_reg_p)
2169 					continue;
2170 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2171 					   pr_reg_p->pr_reg_nacl->initiatorname))
2172 					continue;
2173 
2174 				__core_scsi3_free_registration(dev,
2175 						pr_reg_p, NULL, 0);
2176 			}
2177 		}
2178 
2179 		/*
2180 		 * Release the calling I_T Nexus registration now..
2181 		 */
2182 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2183 		pr_reg = NULL;
2184 
2185 		/*
2186 		 * From spc4r17, section 5.7.11.3 Unregistering
2187 		 *
2188 		 * If the persistent reservation is a registrants only
2189 		 * type, the device server shall establish a unit
2190 		 * attention condition for the initiator port associated
2191 		 * with every registered I_T nexus except for the I_T
2192 		 * nexus on which the PERSISTENT RESERVE OUT command was
2193 		 * received, with the additional sense code set to
2194 		 * RESERVATIONS RELEASED.
2195 		 */
2196 		if (pr_holder &&
2197 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2198 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2199 			list_for_each_entry(pr_reg_p,
2200 					&pr_tmpl->registration_list,
2201 					pr_reg_list) {
2202 
2203 				core_scsi3_ua_allocate(
2204 					pr_reg_p->pr_reg_nacl,
2205 					pr_reg_p->pr_res_mapped_lun,
2206 					0x2A,
2207 					ASCQ_2AH_RESERVATIONS_RELEASED);
2208 			}
2209 		}
2210 
2211 		spin_unlock(&pr_tmpl->registration_lock);
2212 	}
2213 
2214 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2215 
2216 out:
2217 	if (pr_reg)
2218 		core_scsi3_put_pr_reg(pr_reg);
2219 	return ret;
2220 }
2221 
2222 unsigned char *core_scsi3_pr_dump_type(int type)
2223 {
2224 	switch (type) {
2225 	case PR_TYPE_WRITE_EXCLUSIVE:
2226 		return "Write Exclusive Access";
2227 	case PR_TYPE_EXCLUSIVE_ACCESS:
2228 		return "Exclusive Access";
2229 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2230 		return "Write Exclusive Access, Registrants Only";
2231 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2232 		return "Exclusive Access, Registrants Only";
2233 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2234 		return "Write Exclusive Access, All Registrants";
2235 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2236 		return "Exclusive Access, All Registrants";
2237 	default:
2238 		break;
2239 	}
2240 
2241 	return "Unknown SPC-3 PR Type";
2242 }
2243 
2244 static sense_reason_t
2245 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2246 {
2247 	struct se_device *dev = cmd->se_dev;
2248 	struct se_session *se_sess = cmd->se_sess;
2249 	struct se_lun *se_lun = cmd->se_lun;
2250 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2251 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2252 	char i_buf[PR_REG_ISID_ID_LEN];
2253 	sense_reason_t ret;
2254 
2255 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2256 
2257 	if (!se_sess || !se_lun) {
2258 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2259 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2260 	}
2261 	/*
2262 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2263 	 */
2264 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2265 				se_sess);
2266 	if (!pr_reg) {
2267 		pr_err("SPC-3 PR: Unable to locate"
2268 			" PR_REGISTERED *pr_reg for RESERVE\n");
2269 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2270 	}
2271 	/*
2272 	 * From spc4r17 Section 5.7.9: Reserving:
2273 	 *
2274 	 * An application client creates a persistent reservation by issuing
2275 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2276 	 * a registered I_T nexus with the following parameters:
2277 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2278 	 * 	 registered with the logical unit for the I_T nexus; and
2279 	 */
2280 	if (res_key != pr_reg->pr_res_key) {
2281 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2282 			" does not match existing SA REGISTER res_key:"
2283 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2284 		ret = TCM_RESERVATION_CONFLICT;
2285 		goto out_put_pr_reg;
2286 	}
2287 	/*
2288 	 * From spc4r17 Section 5.7.9: Reserving:
2289 	 *
2290 	 * From above:
2291 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2292 	 *     being created.
2293 	 *
2294 	 * Only one persistent reservation is allowed at a time per logical unit
2295 	 * and that persistent reservation has a scope of LU_SCOPE.
2296 	 */
2297 	if (scope != PR_SCOPE_LU_SCOPE) {
2298 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2299 		ret = TCM_INVALID_PARAMETER_LIST;
2300 		goto out_put_pr_reg;
2301 	}
2302 	/*
2303 	 * See if we have an existing PR reservation holder pointer at
2304 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2305 	 * *pr_res_holder.
2306 	 */
2307 	spin_lock(&dev->dev_reservation_lock);
2308 	pr_res_holder = dev->dev_pr_res_holder;
2309 	if (pr_res_holder) {
2310 		/*
2311 		 * From spc4r17 Section 5.7.9: Reserving:
2312 		 *
2313 		 * If the device server receives a PERSISTENT RESERVE OUT
2314 		 * command from an I_T nexus other than a persistent reservation
2315 		 * holder (see 5.7.10) that attempts to create a persistent
2316 		 * reservation when a persistent reservation already exists for
2317 		 * the logical unit, then the command shall be completed with
2318 		 * RESERVATION CONFLICT status.
2319 		 */
2320 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2321 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2322 			pr_err("SPC-3 PR: Attempted RESERVE from"
2323 				" [%s]: %s while reservation already held by"
2324 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2325 				cmd->se_tfo->get_fabric_name(),
2326 				se_sess->se_node_acl->initiatorname,
2327 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2328 				pr_res_holder->pr_reg_nacl->initiatorname);
2329 
2330 			spin_unlock(&dev->dev_reservation_lock);
2331 			ret = TCM_RESERVATION_CONFLICT;
2332 			goto out_put_pr_reg;
2333 		}
2334 		/*
2335 		 * From spc4r17 Section 5.7.9: Reserving:
2336 		 *
2337 		 * If a persistent reservation holder attempts to modify the
2338 		 * type or scope of an existing persistent reservation, the
2339 		 * command shall be completed with RESERVATION CONFLICT status.
2340 		 */
2341 		if ((pr_res_holder->pr_res_type != type) ||
2342 		    (pr_res_holder->pr_res_scope != scope)) {
2343 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2344 			pr_err("SPC-3 PR: Attempted RESERVE from"
2345 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2346 				" while reservation already held by [%s]: %s,"
2347 				" returning RESERVATION_CONFLICT\n",
2348 				cmd->se_tfo->get_fabric_name(),
2349 				se_sess->se_node_acl->initiatorname,
2350 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2351 				pr_res_holder->pr_reg_nacl->initiatorname);
2352 
2353 			spin_unlock(&dev->dev_reservation_lock);
2354 			ret = TCM_RESERVATION_CONFLICT;
2355 			goto out_put_pr_reg;
2356 		}
2357 		/*
2358 		 * From spc4r17 Section 5.7.9: Reserving:
2359 		 *
2360 		 * If the device server receives a PERSISTENT RESERVE OUT
2361 		 * command with RESERVE service action where the TYPE field and
2362 		 * the SCOPE field contain the same values as the existing type
2363 		 * and scope from a persistent reservation holder, it shall not
2364 		 * make any change to the existing persistent reservation and
2365 		 * shall completethe command with GOOD status.
2366 		 */
2367 		spin_unlock(&dev->dev_reservation_lock);
2368 		ret = 0;
2369 		goto out_put_pr_reg;
2370 	}
2371 	/*
2372 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2373 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2374 	 */
2375 	pr_reg->pr_res_scope = scope;
2376 	pr_reg->pr_res_type = type;
2377 	pr_reg->pr_res_holder = 1;
2378 	dev->dev_pr_res_holder = pr_reg;
2379 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2380 
2381 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2382 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2383 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2384 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2385 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2386 			cmd->se_tfo->get_fabric_name(),
2387 			se_sess->se_node_acl->initiatorname,
2388 			i_buf);
2389 	spin_unlock(&dev->dev_reservation_lock);
2390 
2391 	if (pr_tmpl->pr_aptpl_active)
2392 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2393 
2394 	ret = 0;
2395 out_put_pr_reg:
2396 	core_scsi3_put_pr_reg(pr_reg);
2397 	return ret;
2398 }
2399 
2400 static sense_reason_t
2401 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2402 		u64 res_key)
2403 {
2404 	switch (type) {
2405 	case PR_TYPE_WRITE_EXCLUSIVE:
2406 	case PR_TYPE_EXCLUSIVE_ACCESS:
2407 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2408 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2409 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2410 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2411 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2412 	default:
2413 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2414 			" 0x%02x\n", type);
2415 		return TCM_INVALID_CDB_FIELD;
2416 	}
2417 }
2418 
2419 /*
2420  * Called with struct se_device->dev_reservation_lock held.
2421  */
2422 static void __core_scsi3_complete_pro_release(
2423 	struct se_device *dev,
2424 	struct se_node_acl *se_nacl,
2425 	struct t10_pr_registration *pr_reg,
2426 	int explicit,
2427 	int unreg)
2428 {
2429 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2430 	char i_buf[PR_REG_ISID_ID_LEN];
2431 	int pr_res_type = 0, pr_res_scope = 0;
2432 
2433 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2434 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2435 	/*
2436 	 * Go ahead and release the current PR reservation holder.
2437 	 * If an All Registrants reservation is currently active and
2438 	 * a unregister operation is requested, replace the current
2439 	 * dev_pr_res_holder with another active registration.
2440 	 */
2441 	if (dev->dev_pr_res_holder) {
2442 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2443 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2444 		dev->dev_pr_res_holder->pr_res_type = 0;
2445 		dev->dev_pr_res_holder->pr_res_scope = 0;
2446 		dev->dev_pr_res_holder->pr_res_holder = 0;
2447 		dev->dev_pr_res_holder = NULL;
2448 	}
2449 	if (!unreg)
2450 		goto out;
2451 
2452 	spin_lock(&dev->t10_pr.registration_lock);
2453 	list_del_init(&pr_reg->pr_reg_list);
2454 	/*
2455 	 * If the I_T nexus is a reservation holder, the persistent reservation
2456 	 * is of an all registrants type, and the I_T nexus is the last remaining
2457 	 * registered I_T nexus, then the device server shall also release the
2458 	 * persistent reservation.
2459 	 */
2460 	if (!list_empty(&dev->t10_pr.registration_list) &&
2461 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2462 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2463 		dev->dev_pr_res_holder =
2464 			list_entry(dev->t10_pr.registration_list.next,
2465 				   struct t10_pr_registration, pr_reg_list);
2466 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2467 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2468 		dev->dev_pr_res_holder->pr_res_holder = 1;
2469 	}
2470 	spin_unlock(&dev->t10_pr.registration_lock);
2471 out:
2472 	if (!dev->dev_pr_res_holder) {
2473 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2474 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2475 			tfo->get_fabric_name(), (explicit) ? "explicit" :
2476 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2477 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2478 	}
2479 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2480 		tfo->get_fabric_name(), se_nacl->initiatorname,
2481 		i_buf);
2482 	/*
2483 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2484 	 */
2485 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2486 }
2487 
2488 static sense_reason_t
2489 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2490 		u64 res_key)
2491 {
2492 	struct se_device *dev = cmd->se_dev;
2493 	struct se_session *se_sess = cmd->se_sess;
2494 	struct se_lun *se_lun = cmd->se_lun;
2495 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2496 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2497 	sense_reason_t ret = 0;
2498 
2499 	if (!se_sess || !se_lun) {
2500 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2501 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2502 	}
2503 	/*
2504 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2505 	 */
2506 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2507 	if (!pr_reg) {
2508 		pr_err("SPC-3 PR: Unable to locate"
2509 			" PR_REGISTERED *pr_reg for RELEASE\n");
2510 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2511 	}
2512 	/*
2513 	 * From spc4r17 Section 5.7.11.2 Releasing:
2514 	 *
2515 	 * If there is no persistent reservation or in response to a persistent
2516 	 * reservation release request from a registered I_T nexus that is not a
2517 	 * persistent reservation holder (see 5.7.10), the device server shall
2518 	 * do the following:
2519 	 *
2520 	 *     a) Not release the persistent reservation, if any;
2521 	 *     b) Not remove any registrations; and
2522 	 *     c) Complete the command with GOOD status.
2523 	 */
2524 	spin_lock(&dev->dev_reservation_lock);
2525 	pr_res_holder = dev->dev_pr_res_holder;
2526 	if (!pr_res_holder) {
2527 		/*
2528 		 * No persistent reservation, return GOOD status.
2529 		 */
2530 		spin_unlock(&dev->dev_reservation_lock);
2531 		goto out_put_pr_reg;
2532 	}
2533 
2534 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2535 		/*
2536 		 * Release request from a registered I_T nexus that is not a
2537 		 * persistent reservation holder. return GOOD status.
2538 		 */
2539 		spin_unlock(&dev->dev_reservation_lock);
2540 		goto out_put_pr_reg;
2541 	}
2542 
2543 	/*
2544 	 * From spc4r17 Section 5.7.11.2 Releasing:
2545 	 *
2546 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2547 	 * release a persistent reservation.
2548 	 *
2549 	 * An application client releases the persistent reservation by issuing
2550 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2551 	 * an I_T nexus that is a persistent reservation holder with the
2552 	 * following parameters:
2553 	 *
2554 	 *     a) RESERVATION KEY field set to the value of the reservation key
2555 	 *	  that is registered with the logical unit for the I_T nexus;
2556 	 */
2557 	if (res_key != pr_reg->pr_res_key) {
2558 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2559 			" does not match existing SA REGISTER res_key:"
2560 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2561 		spin_unlock(&dev->dev_reservation_lock);
2562 		ret = TCM_RESERVATION_CONFLICT;
2563 		goto out_put_pr_reg;
2564 	}
2565 	/*
2566 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2567 	 *
2568 	 * b) TYPE field and SCOPE field set to match the persistent
2569 	 *    reservation being released.
2570 	 */
2571 	if ((pr_res_holder->pr_res_type != type) ||
2572 	    (pr_res_holder->pr_res_scope != scope)) {
2573 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2574 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2575 			" reservation from [%s]: %s with different TYPE "
2576 			"and/or SCOPE  while reservation already held by"
2577 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2578 			cmd->se_tfo->get_fabric_name(),
2579 			se_sess->se_node_acl->initiatorname,
2580 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2581 			pr_res_holder->pr_reg_nacl->initiatorname);
2582 
2583 		spin_unlock(&dev->dev_reservation_lock);
2584 		ret = TCM_RESERVATION_CONFLICT;
2585 		goto out_put_pr_reg;
2586 	}
2587 	/*
2588 	 * In response to a persistent reservation release request from the
2589 	 * persistent reservation holder the device server shall perform a
2590 	 * release by doing the following as an uninterrupted series of actions:
2591 	 * a) Release the persistent reservation;
2592 	 * b) Not remove any registration(s);
2593 	 * c) If the released persistent reservation is a registrants only type
2594 	 * or all registrants type persistent reservation,
2595 	 *    the device server shall establish a unit attention condition for
2596 	 *    the initiator port associated with every regis-
2597 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2598 	 *    RESERVE OUT command with RELEASE service action was received,
2599 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2600 	 * d) If the persistent reservation is of any other type, the device
2601 	 *    server shall not establish a unit attention condition.
2602 	 */
2603 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2604 					  pr_reg, 1, 0);
2605 
2606 	spin_unlock(&dev->dev_reservation_lock);
2607 
2608 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2609 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2610 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2611 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2612 		/*
2613 		 * If no UNIT ATTENTION conditions will be established for
2614 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2615 		 * go ahead and check for APTPL=1 update+write below
2616 		 */
2617 		goto write_aptpl;
2618 	}
2619 
2620 	spin_lock(&pr_tmpl->registration_lock);
2621 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2622 			pr_reg_list) {
2623 		/*
2624 		 * Do not establish a UNIT ATTENTION condition
2625 		 * for the calling I_T Nexus
2626 		 */
2627 		if (pr_reg_p == pr_reg)
2628 			continue;
2629 
2630 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2631 				pr_reg_p->pr_res_mapped_lun,
2632 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2633 	}
2634 	spin_unlock(&pr_tmpl->registration_lock);
2635 
2636 write_aptpl:
2637 	if (pr_tmpl->pr_aptpl_active)
2638 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2639 
2640 out_put_pr_reg:
2641 	core_scsi3_put_pr_reg(pr_reg);
2642 	return ret;
2643 }
2644 
2645 static sense_reason_t
2646 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2647 {
2648 	struct se_device *dev = cmd->se_dev;
2649 	struct se_node_acl *pr_reg_nacl;
2650 	struct se_session *se_sess = cmd->se_sess;
2651 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2652 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2653 	u32 pr_res_mapped_lun = 0;
2654 	int calling_it_nexus = 0;
2655 	/*
2656 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2657 	 */
2658 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2659 			se_sess->se_node_acl, se_sess);
2660 	if (!pr_reg_n) {
2661 		pr_err("SPC-3 PR: Unable to locate"
2662 			" PR_REGISTERED *pr_reg for CLEAR\n");
2663 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2664 	}
2665 	/*
2666 	 * From spc4r17 section 5.7.11.6, Clearing:
2667 	 *
2668 	 * Any application client may release the persistent reservation and
2669 	 * remove all registrations from a device server by issuing a
2670 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2671 	 * registered I_T nexus with the following parameter:
2672 	 *
2673 	 *	a) RESERVATION KEY field set to the value of the reservation key
2674 	 * 	   that is registered with the logical unit for the I_T nexus.
2675 	 */
2676 	if (res_key != pr_reg_n->pr_res_key) {
2677 		pr_err("SPC-3 PR REGISTER: Received"
2678 			" res_key: 0x%016Lx does not match"
2679 			" existing SA REGISTER res_key:"
2680 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2681 		core_scsi3_put_pr_reg(pr_reg_n);
2682 		return TCM_RESERVATION_CONFLICT;
2683 	}
2684 	/*
2685 	 * a) Release the persistent reservation, if any;
2686 	 */
2687 	spin_lock(&dev->dev_reservation_lock);
2688 	pr_res_holder = dev->dev_pr_res_holder;
2689 	if (pr_res_holder) {
2690 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2691 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2692 						  pr_res_holder, 0, 0);
2693 	}
2694 	spin_unlock(&dev->dev_reservation_lock);
2695 	/*
2696 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2697 	 */
2698 	spin_lock(&pr_tmpl->registration_lock);
2699 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2700 			&pr_tmpl->registration_list, pr_reg_list) {
2701 
2702 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2703 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2704 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2705 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2706 					calling_it_nexus);
2707 		/*
2708 		 * e) Establish a unit attention condition for the initiator
2709 		 *    port associated with every registered I_T nexus other
2710 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2711 		 *    command with CLEAR service action was received, with the
2712 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2713 		 */
2714 		if (!calling_it_nexus)
2715 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2716 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2717 	}
2718 	spin_unlock(&pr_tmpl->registration_lock);
2719 
2720 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2721 		cmd->se_tfo->get_fabric_name());
2722 
2723 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2724 
2725 	core_scsi3_pr_generation(dev);
2726 	return 0;
2727 }
2728 
2729 /*
2730  * Called with struct se_device->dev_reservation_lock held.
2731  */
2732 static void __core_scsi3_complete_pro_preempt(
2733 	struct se_device *dev,
2734 	struct t10_pr_registration *pr_reg,
2735 	struct list_head *preempt_and_abort_list,
2736 	int type,
2737 	int scope,
2738 	enum preempt_type preempt_type)
2739 {
2740 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2741 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2742 	char i_buf[PR_REG_ISID_ID_LEN];
2743 
2744 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2745 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2746 	/*
2747 	 * Do an implicit RELEASE of the existing reservation.
2748 	 */
2749 	if (dev->dev_pr_res_holder)
2750 		__core_scsi3_complete_pro_release(dev, nacl,
2751 						  dev->dev_pr_res_holder, 0, 0);
2752 
2753 	dev->dev_pr_res_holder = pr_reg;
2754 	pr_reg->pr_res_holder = 1;
2755 	pr_reg->pr_res_type = type;
2756 	pr_reg->pr_res_scope = scope;
2757 
2758 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2759 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2760 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2761 		core_scsi3_pr_dump_type(type),
2762 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2763 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2764 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2765 		nacl->initiatorname, i_buf);
2766 	/*
2767 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2768 	 * struct t10_pr_registration to the list that will be compared
2769 	 * against received CDBs..
2770 	 */
2771 	if (preempt_and_abort_list)
2772 		list_add_tail(&pr_reg->pr_reg_abort_list,
2773 				preempt_and_abort_list);
2774 }
2775 
2776 static void core_scsi3_release_preempt_and_abort(
2777 	struct list_head *preempt_and_abort_list,
2778 	struct t10_pr_registration *pr_reg_holder)
2779 {
2780 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2781 
2782 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2783 				pr_reg_abort_list) {
2784 
2785 		list_del(&pr_reg->pr_reg_abort_list);
2786 		if (pr_reg_holder == pr_reg)
2787 			continue;
2788 		if (pr_reg->pr_res_holder) {
2789 			pr_warn("pr_reg->pr_res_holder still set\n");
2790 			continue;
2791 		}
2792 
2793 		pr_reg->pr_reg_deve = NULL;
2794 		pr_reg->pr_reg_nacl = NULL;
2795 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2796 	}
2797 }
2798 
2799 static sense_reason_t
2800 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2801 		u64 sa_res_key, enum preempt_type preempt_type)
2802 {
2803 	struct se_device *dev = cmd->se_dev;
2804 	struct se_node_acl *pr_reg_nacl;
2805 	struct se_session *se_sess = cmd->se_sess;
2806 	LIST_HEAD(preempt_and_abort_list);
2807 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2808 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2809 	u32 pr_res_mapped_lun = 0;
2810 	int all_reg = 0, calling_it_nexus = 0;
2811 	bool sa_res_key_unmatched = sa_res_key != 0;
2812 	int prh_type = 0, prh_scope = 0;
2813 
2814 	if (!se_sess)
2815 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2816 
2817 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2818 				se_sess);
2819 	if (!pr_reg_n) {
2820 		pr_err("SPC-3 PR: Unable to locate"
2821 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2822 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2823 		return TCM_RESERVATION_CONFLICT;
2824 	}
2825 	if (pr_reg_n->pr_res_key != res_key) {
2826 		core_scsi3_put_pr_reg(pr_reg_n);
2827 		return TCM_RESERVATION_CONFLICT;
2828 	}
2829 	if (scope != PR_SCOPE_LU_SCOPE) {
2830 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2831 		core_scsi3_put_pr_reg(pr_reg_n);
2832 		return TCM_INVALID_PARAMETER_LIST;
2833 	}
2834 
2835 	spin_lock(&dev->dev_reservation_lock);
2836 	pr_res_holder = dev->dev_pr_res_holder;
2837 	if (pr_res_holder &&
2838 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2839 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2840 		all_reg = 1;
2841 
2842 	if (!all_reg && !sa_res_key) {
2843 		spin_unlock(&dev->dev_reservation_lock);
2844 		core_scsi3_put_pr_reg(pr_reg_n);
2845 		return TCM_INVALID_PARAMETER_LIST;
2846 	}
2847 	/*
2848 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2849 	 *
2850 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2851 	 * persistent reservation holder or there is no persistent reservation
2852 	 * holder (i.e., there is no persistent reservation), then the device
2853 	 * server shall perform a preempt by doing the following in an
2854 	 * uninterrupted series of actions. (See below..)
2855 	 */
2856 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2857 		/*
2858 		 * No existing or SA Reservation Key matching reservations..
2859 		 *
2860 		 * PROUT SA PREEMPT with All Registrant type reservations are
2861 		 * allowed to be processed without a matching SA Reservation Key
2862 		 */
2863 		spin_lock(&pr_tmpl->registration_lock);
2864 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2865 				&pr_tmpl->registration_list, pr_reg_list) {
2866 			/*
2867 			 * Removing of registrations in non all registrants
2868 			 * type reservations without a matching SA reservation
2869 			 * key.
2870 			 *
2871 			 * a) Remove the registrations for all I_T nexuses
2872 			 *    specified by the SERVICE ACTION RESERVATION KEY
2873 			 *    field;
2874 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2875 			 * c) Process tasks as defined in 5.7.1; and
2876 			 * d) Establish a unit attention condition for the
2877 			 *    initiator port associated with every I_T nexus
2878 			 *    that lost its registration other than the I_T
2879 			 *    nexus on which the PERSISTENT RESERVE OUT command
2880 			 *    was received, with the additional sense code set
2881 			 *    to REGISTRATIONS PREEMPTED.
2882 			 */
2883 			if (!all_reg) {
2884 				if (pr_reg->pr_res_key != sa_res_key)
2885 					continue;
2886 				sa_res_key_unmatched = false;
2887 
2888 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2889 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2890 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2891 				__core_scsi3_free_registration(dev, pr_reg,
2892 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2893 						NULL, calling_it_nexus);
2894 			} else {
2895 				/*
2896 				 * Case for any existing all registrants type
2897 				 * reservation, follow logic in spc4r17 section
2898 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2899 				 *
2900 				 * For a ZERO SA Reservation key, release
2901 				 * all other registrations and do an implicit
2902 				 * release of active persistent reservation.
2903 				 *
2904 				 * For a non-ZERO SA Reservation key, only
2905 				 * release the matching reservation key from
2906 				 * registrations.
2907 				 */
2908 				if ((sa_res_key) &&
2909 				     (pr_reg->pr_res_key != sa_res_key))
2910 					continue;
2911 				sa_res_key_unmatched = false;
2912 
2913 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2914 				if (calling_it_nexus)
2915 					continue;
2916 
2917 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2918 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2919 				__core_scsi3_free_registration(dev, pr_reg,
2920 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2921 						NULL, 0);
2922 			}
2923 			if (!calling_it_nexus)
2924 				core_scsi3_ua_allocate(pr_reg_nacl,
2925 					pr_res_mapped_lun, 0x2A,
2926 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2927 		}
2928 		spin_unlock(&pr_tmpl->registration_lock);
2929 		/*
2930 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2931 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2932 		 * RESERVATION KEY field to a value that does not match any
2933 		 * registered reservation key, then the device server shall
2934 		 * complete the command with RESERVATION CONFLICT status.
2935 		 */
2936 		if (sa_res_key_unmatched) {
2937 			spin_unlock(&dev->dev_reservation_lock);
2938 			core_scsi3_put_pr_reg(pr_reg_n);
2939 			return TCM_RESERVATION_CONFLICT;
2940 		}
2941 		/*
2942 		 * For an existing all registrants type reservation
2943 		 * with a zero SA rservation key, preempt the existing
2944 		 * reservation with the new PR type and scope.
2945 		 */
2946 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2947 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2948 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2949 				type, scope, preempt_type);
2950 
2951 			if (preempt_type == PREEMPT_AND_ABORT)
2952 				core_scsi3_release_preempt_and_abort(
2953 					&preempt_and_abort_list, pr_reg_n);
2954 		}
2955 		spin_unlock(&dev->dev_reservation_lock);
2956 
2957 		if (pr_tmpl->pr_aptpl_active)
2958 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2959 
2960 		core_scsi3_put_pr_reg(pr_reg_n);
2961 		core_scsi3_pr_generation(cmd->se_dev);
2962 		return 0;
2963 	}
2964 	/*
2965 	 * The PREEMPTing SA reservation key matches that of the
2966 	 * existing persistent reservation, first, we check if
2967 	 * we are preempting our own reservation.
2968 	 * From spc4r17, section 5.7.11.4.3 Preempting
2969 	 * persistent reservations and registration handling
2970 	 *
2971 	 * If an all registrants persistent reservation is not
2972 	 * present, it is not an error for the persistent
2973 	 * reservation holder to preempt itself (i.e., a
2974 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
2975 	 * or a PREEMPT AND ABORT service action with the
2976 	 * SERVICE ACTION RESERVATION KEY value equal to the
2977 	 * persistent reservation holder's reservation key that
2978 	 * is received from the persistent reservation holder).
2979 	 * In that case, the device server shall establish the
2980 	 * new persistent reservation and maintain the
2981 	 * registration.
2982 	 */
2983 	prh_type = pr_res_holder->pr_res_type;
2984 	prh_scope = pr_res_holder->pr_res_scope;
2985 	/*
2986 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
2987 	 * persistent reservation holder (see 5.7.10), the device
2988 	 * server shall perform a preempt by doing the following as
2989 	 * an uninterrupted series of actions:
2990 	 *
2991 	 * a) Release the persistent reservation for the holder
2992 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
2993 	 */
2994 	if (pr_reg_n != pr_res_holder)
2995 		__core_scsi3_complete_pro_release(dev,
2996 						  pr_res_holder->pr_reg_nacl,
2997 						  dev->dev_pr_res_holder, 0, 0);
2998 	/*
2999 	 * b) Remove the registrations for all I_T nexuses identified
3000 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3001 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3002 	 *    OUT command. If an all registrants persistent reservation
3003 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3004 	 *    is set to zero, then all registrations shall be removed
3005 	 *    except for that of the I_T nexus that is being used for
3006 	 *    the PERSISTENT RESERVE OUT command;
3007 	 */
3008 	spin_lock(&pr_tmpl->registration_lock);
3009 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3010 			&pr_tmpl->registration_list, pr_reg_list) {
3011 
3012 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3013 		if (calling_it_nexus)
3014 			continue;
3015 
3016 		if (pr_reg->pr_res_key != sa_res_key)
3017 			continue;
3018 
3019 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3020 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3021 		__core_scsi3_free_registration(dev, pr_reg,
3022 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3023 				calling_it_nexus);
3024 		/*
3025 		 * e) Establish a unit attention condition for the initiator
3026 		 *    port associated with every I_T nexus that lost its
3027 		 *    persistent reservation and/or registration, with the
3028 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3029 		 */
3030 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3031 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3032 	}
3033 	spin_unlock(&pr_tmpl->registration_lock);
3034 	/*
3035 	 * c) Establish a persistent reservation for the preempting
3036 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3037 	 */
3038 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3039 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3040 			type, scope, preempt_type);
3041 	/*
3042 	 * d) Process tasks as defined in 5.7.1;
3043 	 * e) See above..
3044 	 * f) If the type or scope has changed, then for every I_T nexus
3045 	 *    whose reservation key was not removed, except for the I_T
3046 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3047 	 *    received, the device server shall establish a unit
3048 	 *    attention condition for the initiator port associated with
3049 	 *    that I_T nexus, with the additional sense code set to
3050 	 *    RESERVATIONS RELEASED. If the type or scope have not
3051 	 *    changed, then no unit attention condition(s) shall be
3052 	 *    established for this reason.
3053 	 */
3054 	if ((prh_type != type) || (prh_scope != scope)) {
3055 		spin_lock(&pr_tmpl->registration_lock);
3056 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3057 				&pr_tmpl->registration_list, pr_reg_list) {
3058 
3059 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3060 			if (calling_it_nexus)
3061 				continue;
3062 
3063 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
3064 					pr_reg->pr_res_mapped_lun, 0x2A,
3065 					ASCQ_2AH_RESERVATIONS_RELEASED);
3066 		}
3067 		spin_unlock(&pr_tmpl->registration_lock);
3068 	}
3069 	spin_unlock(&dev->dev_reservation_lock);
3070 	/*
3071 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3072 	 * All received CDBs for the matching existing reservation and
3073 	 * registrations undergo ABORT_TASK logic.
3074 	 *
3075 	 * From there, core_scsi3_release_preempt_and_abort() will
3076 	 * release every registration in the list (which have already
3077 	 * been removed from the primary pr_reg list), except the
3078 	 * new persistent reservation holder, the calling Initiator Port.
3079 	 */
3080 	if (preempt_type == PREEMPT_AND_ABORT) {
3081 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3082 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3083 						pr_reg_n);
3084 	}
3085 
3086 	if (pr_tmpl->pr_aptpl_active)
3087 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3088 
3089 	core_scsi3_put_pr_reg(pr_reg_n);
3090 	core_scsi3_pr_generation(cmd->se_dev);
3091 	return 0;
3092 }
3093 
3094 static sense_reason_t
3095 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3096 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3097 {
3098 	switch (type) {
3099 	case PR_TYPE_WRITE_EXCLUSIVE:
3100 	case PR_TYPE_EXCLUSIVE_ACCESS:
3101 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3102 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3103 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3104 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3105 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3106 					      sa_res_key, preempt_type);
3107 	default:
3108 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3109 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3110 		return TCM_INVALID_CDB_FIELD;
3111 	}
3112 }
3113 
3114 
3115 static sense_reason_t
3116 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3117 		u64 sa_res_key, int aptpl, int unreg)
3118 {
3119 	struct se_session *se_sess = cmd->se_sess;
3120 	struct se_device *dev = cmd->se_dev;
3121 	struct se_dev_entry *dest_se_deve = NULL;
3122 	struct se_lun *se_lun = cmd->se_lun;
3123 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3124 	struct se_port *se_port;
3125 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3126 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3127 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3128 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3129 	unsigned char *buf;
3130 	const unsigned char *initiator_str;
3131 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
3132 	u32 tid_len, tmp_tid_len;
3133 	int new_reg = 0, type, scope, matching_iname;
3134 	sense_reason_t ret;
3135 	unsigned short rtpi;
3136 	unsigned char proto_ident;
3137 
3138 	if (!se_sess || !se_lun) {
3139 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3140 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3141 	}
3142 
3143 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3144 	se_tpg = se_sess->se_tpg;
3145 	tf_ops = se_tpg->se_tpg_tfo;
3146 	/*
3147 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3148 	 *	Register behaviors for a REGISTER AND MOVE service action
3149 	 *
3150 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3151 	 */
3152 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3153 				se_sess);
3154 	if (!pr_reg) {
3155 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3156 			" *pr_reg for REGISTER_AND_MOVE\n");
3157 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3158 	}
3159 	/*
3160 	 * The provided reservation key much match the existing reservation key
3161 	 * provided during this initiator's I_T nexus registration.
3162 	 */
3163 	if (res_key != pr_reg->pr_res_key) {
3164 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3165 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3166 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3167 		ret = TCM_RESERVATION_CONFLICT;
3168 		goto out_put_pr_reg;
3169 	}
3170 	/*
3171 	 * The service active reservation key needs to be non zero
3172 	 */
3173 	if (!sa_res_key) {
3174 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3175 			" sa_res_key\n");
3176 		ret = TCM_INVALID_PARAMETER_LIST;
3177 		goto out_put_pr_reg;
3178 	}
3179 
3180 	/*
3181 	 * Determine the Relative Target Port Identifier where the reservation
3182 	 * will be moved to for the TransportID containing SCSI initiator WWN
3183 	 * information.
3184 	 */
3185 	buf = transport_kmap_data_sg(cmd);
3186 	if (!buf) {
3187 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3188 		goto out_put_pr_reg;
3189 	}
3190 
3191 	rtpi = (buf[18] & 0xff) << 8;
3192 	rtpi |= buf[19] & 0xff;
3193 	tid_len = (buf[20] & 0xff) << 24;
3194 	tid_len |= (buf[21] & 0xff) << 16;
3195 	tid_len |= (buf[22] & 0xff) << 8;
3196 	tid_len |= buf[23] & 0xff;
3197 	transport_kunmap_data_sg(cmd);
3198 	buf = NULL;
3199 
3200 	if ((tid_len + 24) != cmd->data_length) {
3201 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3202 			" does not equal CDB data_length: %u\n", tid_len,
3203 			cmd->data_length);
3204 		ret = TCM_INVALID_PARAMETER_LIST;
3205 		goto out_put_pr_reg;
3206 	}
3207 
3208 	spin_lock(&dev->se_port_lock);
3209 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3210 		if (se_port->sep_rtpi != rtpi)
3211 			continue;
3212 		dest_se_tpg = se_port->sep_tpg;
3213 		if (!dest_se_tpg)
3214 			continue;
3215 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3216 		if (!dest_tf_ops)
3217 			continue;
3218 
3219 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3220 		spin_unlock(&dev->se_port_lock);
3221 
3222 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3223 			pr_err("core_scsi3_tpg_depend_item() failed"
3224 				" for dest_se_tpg\n");
3225 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3226 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3227 			goto out_put_pr_reg;
3228 		}
3229 
3230 		spin_lock(&dev->se_port_lock);
3231 		break;
3232 	}
3233 	spin_unlock(&dev->se_port_lock);
3234 
3235 	if (!dest_se_tpg || !dest_tf_ops) {
3236 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3237 			" fabric ops from Relative Target Port Identifier:"
3238 			" %hu\n", rtpi);
3239 		ret = TCM_INVALID_PARAMETER_LIST;
3240 		goto out_put_pr_reg;
3241 	}
3242 
3243 	buf = transport_kmap_data_sg(cmd);
3244 	if (!buf) {
3245 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3246 		goto out_put_pr_reg;
3247 	}
3248 	proto_ident = (buf[24] & 0x0f);
3249 
3250 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3251 			" 0x%02x\n", proto_ident);
3252 
3253 	if (proto_ident != dest_se_tpg->proto_id) {
3254 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3255 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3256 			" from fabric: %s\n", proto_ident,
3257 			dest_se_tpg->proto_id,
3258 			dest_tf_ops->get_fabric_name());
3259 		ret = TCM_INVALID_PARAMETER_LIST;
3260 		goto out;
3261 	}
3262 	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
3263 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3264 	if (!initiator_str) {
3265 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3266 			" initiator_str from Transport ID\n");
3267 		ret = TCM_INVALID_PARAMETER_LIST;
3268 		goto out;
3269 	}
3270 
3271 	transport_kunmap_data_sg(cmd);
3272 	buf = NULL;
3273 
3274 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3275 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3276 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3277 		iport_ptr : "");
3278 	/*
3279 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3280 	 * action specifies a TransportID that is the same as the initiator port
3281 	 * of the I_T nexus for the command received, then the command shall
3282 	 * be terminated with CHECK CONDITION status, with the sense key set to
3283 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3284 	 * IN PARAMETER LIST.
3285 	 */
3286 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3287 	matching_iname = (!strcmp(initiator_str,
3288 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3289 	if (!matching_iname)
3290 		goto after_iport_check;
3291 
3292 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3293 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3294 			" matches: %s on received I_T Nexus\n", initiator_str,
3295 			pr_reg_nacl->initiatorname);
3296 		ret = TCM_INVALID_PARAMETER_LIST;
3297 		goto out;
3298 	}
3299 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3300 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3301 			" matches: %s %s on received I_T Nexus\n",
3302 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3303 			pr_reg->pr_reg_isid);
3304 		ret = TCM_INVALID_PARAMETER_LIST;
3305 		goto out;
3306 	}
3307 after_iport_check:
3308 	/*
3309 	 * Locate the destination struct se_node_acl from the received Transport ID
3310 	 */
3311 	mutex_lock(&dest_se_tpg->acl_node_mutex);
3312 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3313 				initiator_str);
3314 	if (dest_node_acl)
3315 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3316 	mutex_unlock(&dest_se_tpg->acl_node_mutex);
3317 
3318 	if (!dest_node_acl) {
3319 		pr_err("Unable to locate %s dest_node_acl for"
3320 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3321 			initiator_str);
3322 		ret = TCM_INVALID_PARAMETER_LIST;
3323 		goto out;
3324 	}
3325 
3326 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3327 		pr_err("core_scsi3_nodeacl_depend_item() for"
3328 			" dest_node_acl\n");
3329 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3330 		dest_node_acl = NULL;
3331 		ret = TCM_INVALID_PARAMETER_LIST;
3332 		goto out;
3333 	}
3334 
3335 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3336 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3337 		dest_node_acl->initiatorname);
3338 
3339 	/*
3340 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3341 	 * PORT IDENTIFIER.
3342 	 */
3343 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3344 	if (!dest_se_deve) {
3345 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3346 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3347 		ret = TCM_INVALID_PARAMETER_LIST;
3348 		goto out;
3349 	}
3350 
3351 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3352 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3353 		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
3354 		dest_se_deve = NULL;
3355 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3356 		goto out;
3357 	}
3358 
3359 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3360 		" ACL for dest_se_deve->mapped_lun: %u\n",
3361 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3362 		dest_se_deve->mapped_lun);
3363 
3364 	/*
3365 	 * A persistent reservation needs to already existing in order to
3366 	 * successfully complete the REGISTER_AND_MOVE service action..
3367 	 */
3368 	spin_lock(&dev->dev_reservation_lock);
3369 	pr_res_holder = dev->dev_pr_res_holder;
3370 	if (!pr_res_holder) {
3371 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3372 			" currently held\n");
3373 		spin_unlock(&dev->dev_reservation_lock);
3374 		ret = TCM_INVALID_CDB_FIELD;
3375 		goto out;
3376 	}
3377 	/*
3378 	 * The received on I_T Nexus must be the reservation holder.
3379 	 *
3380 	 * From spc4r17 section 5.7.8  Table 50 --
3381 	 * 	Register behaviors for a REGISTER AND MOVE service action
3382 	 */
3383 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3384 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3385 			" Nexus is not reservation holder\n");
3386 		spin_unlock(&dev->dev_reservation_lock);
3387 		ret = TCM_RESERVATION_CONFLICT;
3388 		goto out;
3389 	}
3390 	/*
3391 	 * From spc4r17 section 5.7.8: registering and moving reservation
3392 	 *
3393 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3394 	 * action is received and the established persistent reservation is a
3395 	 * Write Exclusive - All Registrants type or Exclusive Access -
3396 	 * All Registrants type reservation, then the command shall be completed
3397 	 * with RESERVATION CONFLICT status.
3398 	 */
3399 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3400 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3401 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3402 			" reservation for type: %s\n",
3403 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3404 		spin_unlock(&dev->dev_reservation_lock);
3405 		ret = TCM_RESERVATION_CONFLICT;
3406 		goto out;
3407 	}
3408 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3409 	/*
3410 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3411 	 */
3412 	type = pr_res_holder->pr_res_type;
3413 	scope = pr_res_holder->pr_res_type;
3414 	/*
3415 	 * c) Associate the reservation key specified in the SERVICE ACTION
3416 	 *    RESERVATION KEY field with the I_T nexus specified as the
3417 	 *    destination of the register and move, where:
3418 	 *    A) The I_T nexus is specified by the TransportID and the
3419 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3420 	 *    B) Regardless of the TransportID format used, the association for
3421 	 *       the initiator port is based on either the initiator port name
3422 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3423 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3424 	 *       transport protocols where port names are not required;
3425 	 * d) Register the reservation key specified in the SERVICE ACTION
3426 	 *    RESERVATION KEY field;
3427 	 * e) Retain the reservation key specified in the SERVICE ACTION
3428 	 *    RESERVATION KEY field and associated information;
3429 	 *
3430 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3431 	 * register an I_T nexus that is already registered with the same
3432 	 * reservation key or a different reservation key.
3433 	 */
3434 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3435 					iport_ptr);
3436 	if (!dest_pr_reg) {
3437 		struct se_lun *dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
3438 				atomic_read(&dest_se_deve->pr_kref.refcount) != 0);
3439 
3440 		spin_unlock(&dev->dev_reservation_lock);
3441 		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
3442 					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
3443 					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
3444 			ret = TCM_INVALID_PARAMETER_LIST;
3445 			goto out;
3446 		}
3447 		spin_lock(&dev->dev_reservation_lock);
3448 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3449 						iport_ptr);
3450 		new_reg = 1;
3451 	}
3452 	/*
3453 	 * f) Release the persistent reservation for the persistent reservation
3454 	 *    holder (i.e., the I_T nexus on which the
3455 	 */
3456 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3457 					  dev->dev_pr_res_holder, 0, 0);
3458 	/*
3459 	 * g) Move the persistent reservation to the specified I_T nexus using
3460 	 *    the same scope and type as the persistent reservation released in
3461 	 *    item f); and
3462 	 */
3463 	dev->dev_pr_res_holder = dest_pr_reg;
3464 	dest_pr_reg->pr_res_holder = 1;
3465 	dest_pr_reg->pr_res_type = type;
3466 	pr_reg->pr_res_scope = scope;
3467 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3468 	/*
3469 	 * Increment PRGeneration for existing registrations..
3470 	 */
3471 	if (!new_reg)
3472 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3473 	spin_unlock(&dev->dev_reservation_lock);
3474 
3475 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3476 		" created new reservation holder TYPE: %s on object RTPI:"
3477 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3478 		core_scsi3_pr_dump_type(type), rtpi,
3479 		dest_pr_reg->pr_res_generation);
3480 	pr_debug("SPC-3 PR Successfully moved reservation from"
3481 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3482 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3483 		i_buf, dest_tf_ops->get_fabric_name(),
3484 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3485 		iport_ptr : "");
3486 	/*
3487 	 * It is now safe to release configfs group dependencies for destination
3488 	 * of Transport ID Initiator Device/Port Identifier
3489 	 */
3490 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3491 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3492 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3493 	/*
3494 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3495 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3496 	 */
3497 	if (unreg) {
3498 		spin_lock(&pr_tmpl->registration_lock);
3499 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3500 		spin_unlock(&pr_tmpl->registration_lock);
3501 	} else
3502 		core_scsi3_put_pr_reg(pr_reg);
3503 
3504 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3505 
3506 	transport_kunmap_data_sg(cmd);
3507 
3508 	core_scsi3_put_pr_reg(dest_pr_reg);
3509 	return 0;
3510 out:
3511 	if (buf)
3512 		transport_kunmap_data_sg(cmd);
3513 	if (dest_se_deve)
3514 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3515 	if (dest_node_acl)
3516 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3517 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3518 
3519 out_put_pr_reg:
3520 	core_scsi3_put_pr_reg(pr_reg);
3521 	return ret;
3522 }
3523 
3524 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3525 {
3526 	unsigned int __v1, __v2;
3527 
3528 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3529 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3530 
3531 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3532 }
3533 
3534 /*
3535  * See spc4r17 section 6.14 Table 170
3536  */
3537 sense_reason_t
3538 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3539 {
3540 	struct se_device *dev = cmd->se_dev;
3541 	unsigned char *cdb = &cmd->t_task_cdb[0];
3542 	unsigned char *buf;
3543 	u64 res_key, sa_res_key;
3544 	int sa, scope, type, aptpl;
3545 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3546 	sense_reason_t ret;
3547 
3548 	/*
3549 	 * Following spc2r20 5.5.1 Reservations overview:
3550 	 *
3551 	 * If a logical unit has been reserved by any RESERVE command and is
3552 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3553 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3554 	 * initiator or service action and shall terminate with a RESERVATION
3555 	 * CONFLICT status.
3556 	 */
3557 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3558 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3559 			" SPC-2 reservation is held, returning"
3560 			" RESERVATION_CONFLICT\n");
3561 		return TCM_RESERVATION_CONFLICT;
3562 	}
3563 
3564 	/*
3565 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3566 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3567 	 */
3568 	if (!cmd->se_sess)
3569 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3570 
3571 	if (cmd->data_length < 24) {
3572 		pr_warn("SPC-PR: Received PR OUT parameter list"
3573 			" length too small: %u\n", cmd->data_length);
3574 		return TCM_INVALID_PARAMETER_LIST;
3575 	}
3576 
3577 	/*
3578 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3579 	 */
3580 	sa = (cdb[1] & 0x1f);
3581 	scope = (cdb[2] & 0xf0);
3582 	type = (cdb[2] & 0x0f);
3583 
3584 	buf = transport_kmap_data_sg(cmd);
3585 	if (!buf)
3586 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3587 
3588 	/*
3589 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3590 	 */
3591 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3592 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3593 	/*
3594 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3595 	 * SCSI TransportIDs.
3596 	 */
3597 	if (sa != PRO_REGISTER_AND_MOVE) {
3598 		spec_i_pt = (buf[20] & 0x08);
3599 		all_tg_pt = (buf[20] & 0x04);
3600 		aptpl = (buf[20] & 0x01);
3601 	} else {
3602 		aptpl = (buf[17] & 0x01);
3603 		unreg = (buf[17] & 0x02);
3604 	}
3605 	/*
3606 	 * If the backend device has been configured to force APTPL metadata
3607 	 * write-out, go ahead and propigate aptpl=1 down now.
3608 	 */
3609 	if (dev->dev_attrib.force_pr_aptpl)
3610 		aptpl = 1;
3611 
3612 	transport_kunmap_data_sg(cmd);
3613 	buf = NULL;
3614 
3615 	/*
3616 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3617 	 */
3618 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER))
3619 		return TCM_INVALID_PARAMETER_LIST;
3620 
3621 	/*
3622 	 * From spc4r17 section 6.14:
3623 	 *
3624 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3625 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3626 	 * the command shall be terminated with CHECK CONDITION status, with
3627 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3628 	 * code set to PARAMETER LIST LENGTH ERROR.
3629 	 */
3630 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3631 	    (cmd->data_length != 24)) {
3632 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3633 			" list length: %u\n", cmd->data_length);
3634 		return TCM_INVALID_PARAMETER_LIST;
3635 	}
3636 
3637 	/*
3638 	 * (core_scsi3_emulate_pro_* function parameters
3639 	 * are defined by spc4r17 Table 174:
3640 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3641 	 */
3642 	switch (sa) {
3643 	case PRO_REGISTER:
3644 		ret = core_scsi3_emulate_pro_register(cmd,
3645 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3646 		break;
3647 	case PRO_RESERVE:
3648 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3649 		break;
3650 	case PRO_RELEASE:
3651 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3652 		break;
3653 	case PRO_CLEAR:
3654 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3655 		break;
3656 	case PRO_PREEMPT:
3657 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3658 					res_key, sa_res_key, PREEMPT);
3659 		break;
3660 	case PRO_PREEMPT_AND_ABORT:
3661 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3662 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3663 		break;
3664 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3665 		ret = core_scsi3_emulate_pro_register(cmd,
3666 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3667 		break;
3668 	case PRO_REGISTER_AND_MOVE:
3669 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3670 				sa_res_key, aptpl, unreg);
3671 		break;
3672 	default:
3673 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3674 			" action: 0x%02x\n", cdb[1] & 0x1f);
3675 		return TCM_INVALID_CDB_FIELD;
3676 	}
3677 
3678 	if (!ret)
3679 		target_complete_cmd(cmd, GOOD);
3680 	return ret;
3681 }
3682 
3683 /*
3684  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3685  *
3686  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3687  */
3688 static sense_reason_t
3689 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3690 {
3691 	struct se_device *dev = cmd->se_dev;
3692 	struct t10_pr_registration *pr_reg;
3693 	unsigned char *buf;
3694 	u32 add_len = 0, off = 8;
3695 
3696 	if (cmd->data_length < 8) {
3697 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3698 			" too small\n", cmd->data_length);
3699 		return TCM_INVALID_CDB_FIELD;
3700 	}
3701 
3702 	buf = transport_kmap_data_sg(cmd);
3703 	if (!buf)
3704 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3705 
3706 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3707 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3708 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3709 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3710 
3711 	spin_lock(&dev->t10_pr.registration_lock);
3712 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3713 			pr_reg_list) {
3714 		/*
3715 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3716 		 * next reservation key list descriptor.
3717 		 */
3718 		if ((add_len + 8) > (cmd->data_length - 8))
3719 			break;
3720 
3721 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3722 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3723 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3724 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3725 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3726 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3727 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3728 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3729 
3730 		add_len += 8;
3731 	}
3732 	spin_unlock(&dev->t10_pr.registration_lock);
3733 
3734 	buf[4] = ((add_len >> 24) & 0xff);
3735 	buf[5] = ((add_len >> 16) & 0xff);
3736 	buf[6] = ((add_len >> 8) & 0xff);
3737 	buf[7] = (add_len & 0xff);
3738 
3739 	transport_kunmap_data_sg(cmd);
3740 
3741 	return 0;
3742 }
3743 
3744 /*
3745  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3746  *
3747  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3748  */
3749 static sense_reason_t
3750 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3751 {
3752 	struct se_device *dev = cmd->se_dev;
3753 	struct t10_pr_registration *pr_reg;
3754 	unsigned char *buf;
3755 	u64 pr_res_key;
3756 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3757 
3758 	if (cmd->data_length < 8) {
3759 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3760 			" too small\n", cmd->data_length);
3761 		return TCM_INVALID_CDB_FIELD;
3762 	}
3763 
3764 	buf = transport_kmap_data_sg(cmd);
3765 	if (!buf)
3766 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3767 
3768 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3769 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3770 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3771 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3772 
3773 	spin_lock(&dev->dev_reservation_lock);
3774 	pr_reg = dev->dev_pr_res_holder;
3775 	if (pr_reg) {
3776 		/*
3777 		 * Set the hardcoded Additional Length
3778 		 */
3779 		buf[4] = ((add_len >> 24) & 0xff);
3780 		buf[5] = ((add_len >> 16) & 0xff);
3781 		buf[6] = ((add_len >> 8) & 0xff);
3782 		buf[7] = (add_len & 0xff);
3783 
3784 		if (cmd->data_length < 22)
3785 			goto err;
3786 
3787 		/*
3788 		 * Set the Reservation key.
3789 		 *
3790 		 * From spc4r17, section 5.7.10:
3791 		 * A persistent reservation holder has its reservation key
3792 		 * returned in the parameter data from a PERSISTENT
3793 		 * RESERVE IN command with READ RESERVATION service action as
3794 		 * follows:
3795 		 * a) For a persistent reservation of the type Write Exclusive
3796 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3797 		 *      the reservation key shall be set to zero; or
3798 		 * b) For all other persistent reservation types, the
3799 		 *    reservation key shall be set to the registered
3800 		 *    reservation key for the I_T nexus that holds the
3801 		 *    persistent reservation.
3802 		 */
3803 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3804 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3805 			pr_res_key = 0;
3806 		else
3807 			pr_res_key = pr_reg->pr_res_key;
3808 
3809 		buf[8] = ((pr_res_key >> 56) & 0xff);
3810 		buf[9] = ((pr_res_key >> 48) & 0xff);
3811 		buf[10] = ((pr_res_key >> 40) & 0xff);
3812 		buf[11] = ((pr_res_key >> 32) & 0xff);
3813 		buf[12] = ((pr_res_key >> 24) & 0xff);
3814 		buf[13] = ((pr_res_key >> 16) & 0xff);
3815 		buf[14] = ((pr_res_key >> 8) & 0xff);
3816 		buf[15] = (pr_res_key & 0xff);
3817 		/*
3818 		 * Set the SCOPE and TYPE
3819 		 */
3820 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3821 			  (pr_reg->pr_res_type & 0x0f);
3822 	}
3823 
3824 err:
3825 	spin_unlock(&dev->dev_reservation_lock);
3826 	transport_kunmap_data_sg(cmd);
3827 
3828 	return 0;
3829 }
3830 
3831 /*
3832  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3833  *
3834  * See spc4r17 section 6.13.4 Table 165
3835  */
3836 static sense_reason_t
3837 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3838 {
3839 	struct se_device *dev = cmd->se_dev;
3840 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3841 	unsigned char *buf;
3842 	u16 add_len = 8; /* Hardcoded to 8. */
3843 
3844 	if (cmd->data_length < 6) {
3845 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3846 			" %u too small\n", cmd->data_length);
3847 		return TCM_INVALID_CDB_FIELD;
3848 	}
3849 
3850 	buf = transport_kmap_data_sg(cmd);
3851 	if (!buf)
3852 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3853 
3854 	buf[0] = ((add_len >> 8) & 0xff);
3855 	buf[1] = (add_len & 0xff);
3856 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3857 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3858 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3859 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3860 	/*
3861 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3862 	 * set the TMV: Task Mask Valid bit.
3863 	 */
3864 	buf[3] |= 0x80;
3865 	/*
3866 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3867 	 */
3868 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3869 	/*
3870 	 * PTPL_A: Persistence across Target Power Loss Active bit
3871 	 */
3872 	if (pr_tmpl->pr_aptpl_active)
3873 		buf[3] |= 0x01;
3874 	/*
3875 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3876 	 */
3877 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3878 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3879 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3880 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3881 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3882 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3883 
3884 	transport_kunmap_data_sg(cmd);
3885 
3886 	return 0;
3887 }
3888 
3889 /*
3890  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3891  *
3892  * See spc4r17 section 6.13.5 Table 168 and 169
3893  */
3894 static sense_reason_t
3895 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3896 {
3897 	struct se_device *dev = cmd->se_dev;
3898 	struct se_node_acl *se_nacl;
3899 	struct se_portal_group *se_tpg;
3900 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3901 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3902 	unsigned char *buf;
3903 	u32 add_desc_len = 0, add_len = 0;
3904 	u32 off = 8; /* off into first Full Status descriptor */
3905 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3906 	int exp_desc_len, desc_len;
3907 	bool all_reg = false;
3908 
3909 	if (cmd->data_length < 8) {
3910 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3911 			" too small\n", cmd->data_length);
3912 		return TCM_INVALID_CDB_FIELD;
3913 	}
3914 
3915 	buf = transport_kmap_data_sg(cmd);
3916 	if (!buf)
3917 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3918 
3919 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3920 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3921 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3922 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3923 
3924 	spin_lock(&dev->dev_reservation_lock);
3925 	if (dev->dev_pr_res_holder) {
3926 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3927 
3928 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3929 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3930 			all_reg = true;
3931 			pr_res_type = pr_holder->pr_res_type;
3932 			pr_res_scope = pr_holder->pr_res_scope;
3933 		}
3934 	}
3935 	spin_unlock(&dev->dev_reservation_lock);
3936 
3937 	spin_lock(&pr_tmpl->registration_lock);
3938 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3939 			&pr_tmpl->registration_list, pr_reg_list) {
3940 
3941 		se_nacl = pr_reg->pr_reg_nacl;
3942 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3943 		add_desc_len = 0;
3944 
3945 		atomic_inc_mb(&pr_reg->pr_res_holders);
3946 		spin_unlock(&pr_tmpl->registration_lock);
3947 		/*
3948 		 * Determine expected length of $FABRIC_MOD specific
3949 		 * TransportID full status descriptor..
3950 		 */
3951 		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
3952 					&format_code);
3953 		if (exp_desc_len < 0 ||
3954 		    exp_desc_len + add_len > cmd->data_length) {
3955 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3956 				" out of buffer: %d\n", cmd->data_length);
3957 			spin_lock(&pr_tmpl->registration_lock);
3958 			atomic_dec_mb(&pr_reg->pr_res_holders);
3959 			break;
3960 		}
3961 		/*
3962 		 * Set RESERVATION KEY
3963 		 */
3964 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3965 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3966 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3967 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3968 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3969 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3970 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3971 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3972 		off += 4; /* Skip Over Reserved area */
3973 
3974 		/*
3975 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3976 		 */
3977 		if (pr_reg->pr_reg_all_tg_pt)
3978 			buf[off] = 0x02;
3979 		/*
3980 		 * The struct se_lun pointer will be present for the
3981 		 * reservation holder for PR_HOLDER bit.
3982 		 *
3983 		 * Also, if this registration is the reservation
3984 		 * holder or there is an All Registrants reservation
3985 		 * active, fill in SCOPE and TYPE in the next byte.
3986 		 */
3987 		if (pr_reg->pr_res_holder) {
3988 			buf[off++] |= 0x01;
3989 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3990 				     (pr_reg->pr_res_type & 0x0f);
3991 		} else if (all_reg) {
3992 			buf[off++] |= 0x01;
3993 			buf[off++] = (pr_res_scope & 0xf0) |
3994 				     (pr_res_type & 0x0f);
3995 		} else {
3996 			off += 2;
3997 		}
3998 
3999 		off += 4; /* Skip over reserved area */
4000 		/*
4001 		 * From spc4r17 6.3.15:
4002 		 *
4003 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4004 		 * IDENTIFIER field contains the relative port identifier (see
4005 		 * 3.1.120) of the target port that is part of the I_T nexus
4006 		 * described by this full status descriptor. If the ALL_TG_PT
4007 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4008 		 * IDENTIFIER field are not defined by this standard.
4009 		 */
4010 		if (!pr_reg->pr_reg_all_tg_pt) {
4011 			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;
4012 
4013 			buf[off++] = ((sep_rtpi >> 8) & 0xff);
4014 			buf[off++] = (sep_rtpi & 0xff);
4015 		} else
4016 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
4017 
4018 		buf[off+4] = se_tpg->proto_id;
4019 
4020 		/*
4021 		 * Now, have the $FABRIC_MOD fill in the transport ID.
4022 		 */
4023 		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
4024 				&format_code, &buf[off+4]);
4025 
4026 		spin_lock(&pr_tmpl->registration_lock);
4027 		atomic_dec_mb(&pr_reg->pr_res_holders);
4028 
4029 		if (desc_len < 0)
4030 			break;
4031 		/*
4032 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4033 		 */
4034 		buf[off++] = ((desc_len >> 24) & 0xff);
4035 		buf[off++] = ((desc_len >> 16) & 0xff);
4036 		buf[off++] = ((desc_len >> 8) & 0xff);
4037 		buf[off++] = (desc_len & 0xff);
4038 		/*
4039 		 * Size of full desctipor header minus TransportID
4040 		 * containing $FABRIC_MOD specific) initiator device/port
4041 		 * WWN information.
4042 		 *
4043 		 *  See spc4r17 Section 6.13.5 Table 169
4044 		 */
4045 		add_desc_len = (24 + desc_len);
4046 
4047 		off += desc_len;
4048 		add_len += add_desc_len;
4049 	}
4050 	spin_unlock(&pr_tmpl->registration_lock);
4051 	/*
4052 	 * Set ADDITIONAL_LENGTH
4053 	 */
4054 	buf[4] = ((add_len >> 24) & 0xff);
4055 	buf[5] = ((add_len >> 16) & 0xff);
4056 	buf[6] = ((add_len >> 8) & 0xff);
4057 	buf[7] = (add_len & 0xff);
4058 
4059 	transport_kunmap_data_sg(cmd);
4060 
4061 	return 0;
4062 }
4063 
4064 sense_reason_t
4065 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4066 {
4067 	sense_reason_t ret;
4068 
4069 	/*
4070 	 * Following spc2r20 5.5.1 Reservations overview:
4071 	 *
4072 	 * If a logical unit has been reserved by any RESERVE command and is
4073 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4074 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4075 	 * initiator or service action and shall terminate with a RESERVATION
4076 	 * CONFLICT status.
4077 	 */
4078 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4079 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4080 			" SPC-2 reservation is held, returning"
4081 			" RESERVATION_CONFLICT\n");
4082 		return TCM_RESERVATION_CONFLICT;
4083 	}
4084 
4085 	switch (cmd->t_task_cdb[1] & 0x1f) {
4086 	case PRI_READ_KEYS:
4087 		ret = core_scsi3_pri_read_keys(cmd);
4088 		break;
4089 	case PRI_READ_RESERVATION:
4090 		ret = core_scsi3_pri_read_reservation(cmd);
4091 		break;
4092 	case PRI_REPORT_CAPABILITIES:
4093 		ret = core_scsi3_pri_report_capabilities(cmd);
4094 		break;
4095 	case PRI_READ_FULL_STATUS:
4096 		ret = core_scsi3_pri_read_full_status(cmd);
4097 		break;
4098 	default:
4099 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4100 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4101 		return TCM_INVALID_CDB_FIELD;
4102 	}
4103 
4104 	if (!ret)
4105 		target_complete_cmd(cmd, GOOD);
4106 	return ret;
4107 }
4108 
4109 sense_reason_t
4110 target_check_reservation(struct se_cmd *cmd)
4111 {
4112 	struct se_device *dev = cmd->se_dev;
4113 	sense_reason_t ret;
4114 
4115 	if (!cmd->se_sess)
4116 		return 0;
4117 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4118 		return 0;
4119 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
4120 		return 0;
4121 
4122 	spin_lock(&dev->dev_reservation_lock);
4123 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4124 		ret = target_scsi2_reservation_check(cmd);
4125 	else
4126 		ret = target_scsi3_pr_reservation_check(cmd);
4127 	spin_unlock(&dev->dev_reservation_lock);
4128 
4129 	return ret;
4130 }
4131