xref: /linux/drivers/target/target_core_pr.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 /*******************************************************************************
2  * Filename:  target_core_pr.c
3  *
4  * This file contains SPC-3 compliant persistent reservations and
5  * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
6  *
7  * (c) Copyright 2009-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24  *
25  ******************************************************************************/
26 
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/list.h>
30 #include <linux/file.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_cmnd.h>
33 #include <asm/unaligned.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_backend.h>
37 #include <target/target_core_fabric.h>
38 #include <target/target_core_configfs.h>
39 
40 #include "target_core_internal.h"
41 #include "target_core_pr.h"
42 #include "target_core_ua.h"
43 
44 /*
45  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
46  */
47 struct pr_transport_id_holder {
48 	int dest_local_nexus;
49 	struct t10_pr_registration *dest_pr_reg;
50 	struct se_portal_group *dest_tpg;
51 	struct se_node_acl *dest_node_acl;
52 	struct se_dev_entry *dest_se_deve;
53 	struct list_head dest_list;
54 };
55 
56 void core_pr_dump_initiator_port(
57 	struct t10_pr_registration *pr_reg,
58 	char *buf,
59 	u32 size)
60 {
61 	if (!pr_reg->isid_present_at_reg)
62 		buf[0] = '\0';
63 
64 	snprintf(buf, size, ",i,0x%s", pr_reg->pr_reg_isid);
65 }
66 
67 enum register_type {
68 	REGISTER,
69 	REGISTER_AND_IGNORE_EXISTING_KEY,
70 	REGISTER_AND_MOVE,
71 };
72 
73 enum preempt_type {
74 	PREEMPT,
75 	PREEMPT_AND_ABORT,
76 };
77 
78 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
79 					      struct t10_pr_registration *, int, int);
80 
81 static sense_reason_t
82 target_scsi2_reservation_check(struct se_cmd *cmd)
83 {
84 	struct se_device *dev = cmd->se_dev;
85 	struct se_session *sess = cmd->se_sess;
86 
87 	switch (cmd->t_task_cdb[0]) {
88 	case INQUIRY:
89 	case RELEASE:
90 	case RELEASE_10:
91 		return 0;
92 	default:
93 		break;
94 	}
95 
96 	if (!dev->dev_reserved_node_acl || !sess)
97 		return 0;
98 
99 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
100 		return TCM_RESERVATION_CONFLICT;
101 
102 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
103 		if (dev->dev_res_bin_isid != sess->sess_bin_isid)
104 			return TCM_RESERVATION_CONFLICT;
105 	}
106 
107 	return 0;
108 }
109 
110 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
111 					struct se_node_acl *, struct se_session *);
112 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
113 
114 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
115 {
116 	struct se_session *se_sess = cmd->se_sess;
117 	struct se_device *dev = cmd->se_dev;
118 	struct t10_pr_registration *pr_reg;
119 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
120 	int conflict = 0;
121 
122 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
123 			se_sess);
124 	if (pr_reg) {
125 		/*
126 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
127 		 * behavior
128 		 *
129 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
130 		 * status, but no reservation shall be established and the
131 		 * persistent reservation shall not be changed, if the command
132 		 * is received from a) and b) below.
133 		 *
134 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
135 		 * status, but the persistent reservation shall not be released,
136 		 * if the command is received from a) and b)
137 		 *
138 		 * a) An I_T nexus that is a persistent reservation holder; or
139 		 * b) An I_T nexus that is registered if a registrants only or
140 		 *    all registrants type persistent reservation is present.
141 		 *
142 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
143 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
144 		 * as defined in SPC-2.
145 		 */
146 		if (pr_reg->pr_res_holder) {
147 			core_scsi3_put_pr_reg(pr_reg);
148 			return 1;
149 		}
150 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
151 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
152 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
153 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
154 			core_scsi3_put_pr_reg(pr_reg);
155 			return 1;
156 		}
157 		core_scsi3_put_pr_reg(pr_reg);
158 		conflict = 1;
159 	} else {
160 		/*
161 		 * Following spc2r20 5.5.1 Reservations overview:
162 		 *
163 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
164 		 * command with the REGISTER or the REGISTER AND IGNORE
165 		 * EXISTING KEY service action and is still registered by any
166 		 * initiator, all RESERVE commands and all RELEASE commands
167 		 * regardless of initiator shall conflict and shall terminate
168 		 * with a RESERVATION CONFLICT status.
169 		 */
170 		spin_lock(&pr_tmpl->registration_lock);
171 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
172 		spin_unlock(&pr_tmpl->registration_lock);
173 	}
174 
175 	if (conflict) {
176 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
177 			" while active SPC-3 registrations exist,"
178 			" returning RESERVATION_CONFLICT\n");
179 		return -EBUSY;
180 	}
181 
182 	return 0;
183 }
184 
185 sense_reason_t
186 target_scsi2_reservation_release(struct se_cmd *cmd)
187 {
188 	struct se_device *dev = cmd->se_dev;
189 	struct se_session *sess = cmd->se_sess;
190 	struct se_portal_group *tpg;
191 	int rc;
192 
193 	if (!sess || !sess->se_tpg)
194 		goto out;
195 	rc = target_check_scsi2_reservation_conflict(cmd);
196 	if (rc == 1)
197 		goto out;
198 	if (rc < 0)
199 		return TCM_RESERVATION_CONFLICT;
200 
201 	spin_lock(&dev->dev_reservation_lock);
202 	if (!dev->dev_reserved_node_acl || !sess)
203 		goto out_unlock;
204 
205 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
206 		goto out_unlock;
207 
208 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
209 		goto out_unlock;
210 
211 	dev->dev_reserved_node_acl = NULL;
212 	dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
213 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
214 		dev->dev_res_bin_isid = 0;
215 		dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS_WITH_ISID;
216 	}
217 	tpg = sess->se_tpg;
218 	pr_debug("SCSI-2 Released reservation for %s LUN: %u ->"
219 		" MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
220 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
221 		sess->se_node_acl->initiatorname);
222 
223 out_unlock:
224 	spin_unlock(&dev->dev_reservation_lock);
225 out:
226 	target_complete_cmd(cmd, GOOD);
227 	return 0;
228 }
229 
230 sense_reason_t
231 target_scsi2_reservation_reserve(struct se_cmd *cmd)
232 {
233 	struct se_device *dev = cmd->se_dev;
234 	struct se_session *sess = cmd->se_sess;
235 	struct se_portal_group *tpg;
236 	sense_reason_t ret = 0;
237 	int rc;
238 
239 	if ((cmd->t_task_cdb[1] & 0x01) &&
240 	    (cmd->t_task_cdb[1] & 0x02)) {
241 		pr_err("LongIO and Obselete Bits set, returning"
242 				" ILLEGAL_REQUEST\n");
243 		return TCM_UNSUPPORTED_SCSI_OPCODE;
244 	}
245 	/*
246 	 * This is currently the case for target_core_mod passthrough struct se_cmd
247 	 * ops
248 	 */
249 	if (!sess || !sess->se_tpg)
250 		goto out;
251 	rc = target_check_scsi2_reservation_conflict(cmd);
252 	if (rc == 1)
253 		goto out;
254 
255 	if (rc < 0)
256 		return TCM_RESERVATION_CONFLICT;
257 
258 	tpg = sess->se_tpg;
259 	spin_lock(&dev->dev_reservation_lock);
260 	if (dev->dev_reserved_node_acl &&
261 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
262 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
263 			tpg->se_tpg_tfo->get_fabric_name());
264 		pr_err("Original reserver LUN: %u %s\n",
265 			cmd->se_lun->unpacked_lun,
266 			dev->dev_reserved_node_acl->initiatorname);
267 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
268 			" from %s \n", cmd->se_lun->unpacked_lun,
269 			cmd->se_deve->mapped_lun,
270 			sess->se_node_acl->initiatorname);
271 		ret = TCM_RESERVATION_CONFLICT;
272 		goto out_unlock;
273 	}
274 
275 	dev->dev_reserved_node_acl = sess->se_node_acl;
276 	dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS;
277 	if (sess->sess_bin_isid != 0) {
278 		dev->dev_res_bin_isid = sess->sess_bin_isid;
279 		dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS_WITH_ISID;
280 	}
281 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
282 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
283 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
284 		sess->se_node_acl->initiatorname);
285 
286 out_unlock:
287 	spin_unlock(&dev->dev_reservation_lock);
288 out:
289 	if (!ret)
290 		target_complete_cmd(cmd, GOOD);
291 	return ret;
292 }
293 
294 
295 /*
296  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
297  *
298  * This function is called by those initiator ports who are *NOT*
299  * the active PR reservation holder when a reservation is present.
300  */
301 static int core_scsi3_pr_seq_non_holder(
302 	struct se_cmd *cmd,
303 	u32 pr_reg_type)
304 {
305 	unsigned char *cdb = cmd->t_task_cdb;
306 	struct se_dev_entry *se_deve;
307 	struct se_session *se_sess = cmd->se_sess;
308 	int other_cdb = 0, ignore_reg;
309 	int registered_nexus = 0, ret = 1; /* Conflict by default */
310 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
311 	int we = 0; /* Write Exclusive */
312 	int legacy = 0; /* Act like a legacy device and return
313 			 * RESERVATION CONFLICT on some CDBs */
314 
315 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
316 	/*
317 	 * Determine if the registration should be ignored due to
318 	 * non-matching ISIDs in target_scsi3_pr_reservation_check().
319 	 */
320 	ignore_reg = (pr_reg_type & 0x80000000);
321 	if (ignore_reg)
322 		pr_reg_type &= ~0x80000000;
323 
324 	switch (pr_reg_type) {
325 	case PR_TYPE_WRITE_EXCLUSIVE:
326 		we = 1;
327 	case PR_TYPE_EXCLUSIVE_ACCESS:
328 		/*
329 		 * Some commands are only allowed for the persistent reservation
330 		 * holder.
331 		 */
332 		if ((se_deve->def_pr_registered) && !(ignore_reg))
333 			registered_nexus = 1;
334 		break;
335 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
336 		we = 1;
337 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
338 		/*
339 		 * Some commands are only allowed for registered I_T Nexuses.
340 		 */
341 		reg_only = 1;
342 		if ((se_deve->def_pr_registered) && !(ignore_reg))
343 			registered_nexus = 1;
344 		break;
345 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
346 		we = 1;
347 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
348 		/*
349 		 * Each registered I_T Nexus is a reservation holder.
350 		 */
351 		all_reg = 1;
352 		if ((se_deve->def_pr_registered) && !(ignore_reg))
353 			registered_nexus = 1;
354 		break;
355 	default:
356 		return -EINVAL;
357 	}
358 	/*
359 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
360 	 */
361 	switch (cdb[0]) {
362 	case SECURITY_PROTOCOL_IN:
363 		if (registered_nexus)
364 			return 0;
365 		ret = (we) ? 0 : 1;
366 		break;
367 	case MODE_SENSE:
368 	case MODE_SENSE_10:
369 	case READ_ATTRIBUTE:
370 	case READ_BUFFER:
371 	case RECEIVE_DIAGNOSTIC:
372 		if (legacy) {
373 			ret = 1;
374 			break;
375 		}
376 		if (registered_nexus) {
377 			ret = 0;
378 			break;
379 		}
380 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
381 		break;
382 	case PERSISTENT_RESERVE_OUT:
383 		/*
384 		 * This follows PERSISTENT_RESERVE_OUT service actions that
385 		 * are allowed in the presence of various reservations.
386 		 * See spc4r17, table 46
387 		 */
388 		switch (cdb[1] & 0x1f) {
389 		case PRO_CLEAR:
390 		case PRO_PREEMPT:
391 		case PRO_PREEMPT_AND_ABORT:
392 			ret = (registered_nexus) ? 0 : 1;
393 			break;
394 		case PRO_REGISTER:
395 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
396 			ret = 0;
397 			break;
398 		case PRO_REGISTER_AND_MOVE:
399 		case PRO_RESERVE:
400 			ret = 1;
401 			break;
402 		case PRO_RELEASE:
403 			ret = (registered_nexus) ? 0 : 1;
404 			break;
405 		default:
406 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
407 				" action: 0x%02x\n", cdb[1] & 0x1f);
408 			return -EINVAL;
409 		}
410 		break;
411 	case RELEASE:
412 	case RELEASE_10:
413 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
414 		ret = 0;
415 		break;
416 	case RESERVE:
417 	case RESERVE_10:
418 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
419 		ret = 0;
420 		break;
421 	case TEST_UNIT_READY:
422 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
423 		break;
424 	case MAINTENANCE_IN:
425 		switch (cdb[1] & 0x1f) {
426 		case MI_MANAGEMENT_PROTOCOL_IN:
427 			if (registered_nexus) {
428 				ret = 0;
429 				break;
430 			}
431 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
432 			break;
433 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
434 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
435 			if (legacy) {
436 				ret = 1;
437 				break;
438 			}
439 			if (registered_nexus) {
440 				ret = 0;
441 				break;
442 			}
443 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
444 			break;
445 		case MI_REPORT_ALIASES:
446 		case MI_REPORT_IDENTIFYING_INFORMATION:
447 		case MI_REPORT_PRIORITY:
448 		case MI_REPORT_TARGET_PGS:
449 		case MI_REPORT_TIMESTAMP:
450 			ret = 0; /* Allowed */
451 			break;
452 		default:
453 			pr_err("Unknown MI Service Action: 0x%02x\n",
454 				(cdb[1] & 0x1f));
455 			return -EINVAL;
456 		}
457 		break;
458 	case ACCESS_CONTROL_IN:
459 	case ACCESS_CONTROL_OUT:
460 	case INQUIRY:
461 	case LOG_SENSE:
462 	case SERVICE_ACTION_IN_12:
463 	case REPORT_LUNS:
464 	case REQUEST_SENSE:
465 	case PERSISTENT_RESERVE_IN:
466 		ret = 0; /*/ Allowed CDBs */
467 		break;
468 	default:
469 		other_cdb = 1;
470 		break;
471 	}
472 	/*
473 	 * Case where the CDB is explicitly allowed in the above switch
474 	 * statement.
475 	 */
476 	if (!ret && !other_cdb) {
477 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
478 			" reservation holder\n", cdb[0],
479 			core_scsi3_pr_dump_type(pr_reg_type));
480 
481 		return ret;
482 	}
483 	/*
484 	 * Check if write exclusive initiator ports *NOT* holding the
485 	 * WRITE_EXCLUSIVE_* reservation.
486 	 */
487 	if (we && !registered_nexus) {
488 		if (cmd->data_direction == DMA_TO_DEVICE) {
489 			/*
490 			 * Conflict for write exclusive
491 			 */
492 			pr_debug("%s Conflict for unregistered nexus"
493 				" %s CDB: 0x%02x to %s reservation\n",
494 				transport_dump_cmd_direction(cmd),
495 				se_sess->se_node_acl->initiatorname, cdb[0],
496 				core_scsi3_pr_dump_type(pr_reg_type));
497 			return 1;
498 		} else {
499 			/*
500 			 * Allow non WRITE CDBs for all Write Exclusive
501 			 * PR TYPEs to pass for registered and
502 			 * non-registered_nexuxes NOT holding the reservation.
503 			 *
504 			 * We only make noise for the unregisterd nexuses,
505 			 * as we expect registered non-reservation holding
506 			 * nexuses to issue CDBs.
507 			 */
508 
509 			if (!registered_nexus) {
510 				pr_debug("Allowing implicit CDB: 0x%02x"
511 					" for %s reservation on unregistered"
512 					" nexus\n", cdb[0],
513 					core_scsi3_pr_dump_type(pr_reg_type));
514 			}
515 
516 			return 0;
517 		}
518 	} else if ((reg_only) || (all_reg)) {
519 		if (registered_nexus) {
520 			/*
521 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
522 			 * allow commands from registered nexuses.
523 			 */
524 
525 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
526 				" reservation\n", cdb[0],
527 				core_scsi3_pr_dump_type(pr_reg_type));
528 
529 			return 0;
530 		}
531        } else if (we && registered_nexus) {
532                /*
533                 * Reads are allowed for Write Exclusive locks
534                 * from all registrants.
535                 */
536                if (cmd->data_direction == DMA_FROM_DEVICE) {
537                        pr_debug("Allowing READ CDB: 0x%02x for %s"
538                                " reservation\n", cdb[0],
539                                core_scsi3_pr_dump_type(pr_reg_type));
540 
541                        return 0;
542                }
543 	}
544 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
545 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
546 		(registered_nexus) ? "" : "un",
547 		se_sess->se_node_acl->initiatorname, cdb[0],
548 		core_scsi3_pr_dump_type(pr_reg_type));
549 
550 	return 1; /* Conflict by default */
551 }
552 
553 static sense_reason_t
554 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
555 {
556 	struct se_device *dev = cmd->se_dev;
557 	struct se_session *sess = cmd->se_sess;
558 	u32 pr_reg_type;
559 
560 	if (!dev->dev_pr_res_holder)
561 		return 0;
562 
563 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
564 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
565 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
566 		goto check_nonholder;
567 
568 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
569 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
570 		    sess->sess_bin_isid) {
571 			pr_reg_type |= 0x80000000;
572 			goto check_nonholder;
573 		}
574 	}
575 
576 	return 0;
577 
578 check_nonholder:
579 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type))
580 		return TCM_RESERVATION_CONFLICT;
581 	return 0;
582 }
583 
584 static u32 core_scsi3_pr_generation(struct se_device *dev)
585 {
586 	u32 prg;
587 
588 	/*
589 	 * PRGeneration field shall contain the value of a 32-bit wrapping
590 	 * counter mainted by the device server.
591 	 *
592 	 * Note that this is done regardless of Active Persist across
593 	 * Target PowerLoss (APTPL)
594 	 *
595 	 * See spc4r17 section 6.3.12 READ_KEYS service action
596 	 */
597 	spin_lock(&dev->dev_reservation_lock);
598 	prg = dev->t10_pr.pr_generation++;
599 	spin_unlock(&dev->dev_reservation_lock);
600 
601 	return prg;
602 }
603 
604 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
605 	struct se_device *dev,
606 	struct se_node_acl *nacl,
607 	struct se_dev_entry *deve,
608 	unsigned char *isid,
609 	u64 sa_res_key,
610 	int all_tg_pt,
611 	int aptpl)
612 {
613 	struct t10_pr_registration *pr_reg;
614 
615 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
616 	if (!pr_reg) {
617 		pr_err("Unable to allocate struct t10_pr_registration\n");
618 		return NULL;
619 	}
620 
621 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
622 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
623 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
624 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
625 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
626 	atomic_set(&pr_reg->pr_res_holders, 0);
627 	pr_reg->pr_reg_nacl = nacl;
628 	pr_reg->pr_reg_deve = deve;
629 	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
630 	pr_reg->pr_aptpl_target_lun = deve->se_lun->unpacked_lun;
631 	pr_reg->pr_res_key = sa_res_key;
632 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
633 	pr_reg->pr_reg_aptpl = aptpl;
634 	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
635 	/*
636 	 * If an ISID value for this SCSI Initiator Port exists,
637 	 * save it to the registration now.
638 	 */
639 	if (isid != NULL) {
640 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
641 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
642 		pr_reg->isid_present_at_reg = 1;
643 	}
644 
645 	return pr_reg;
646 }
647 
648 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
649 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
650 
651 /*
652  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
653  * modes.
654  */
655 static struct t10_pr_registration *__core_scsi3_alloc_registration(
656 	struct se_device *dev,
657 	struct se_node_acl *nacl,
658 	struct se_dev_entry *deve,
659 	unsigned char *isid,
660 	u64 sa_res_key,
661 	int all_tg_pt,
662 	int aptpl)
663 {
664 	struct se_dev_entry *deve_tmp;
665 	struct se_node_acl *nacl_tmp;
666 	struct se_port *port, *port_tmp;
667 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
668 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
669 	int ret;
670 	/*
671 	 * Create a registration for the I_T Nexus upon which the
672 	 * PROUT REGISTER was received.
673 	 */
674 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, deve, isid,
675 			sa_res_key, all_tg_pt, aptpl);
676 	if (!pr_reg)
677 		return NULL;
678 	/*
679 	 * Return pointer to pr_reg for ALL_TG_PT=0
680 	 */
681 	if (!all_tg_pt)
682 		return pr_reg;
683 	/*
684 	 * Create list of matching SCSI Initiator Port registrations
685 	 * for ALL_TG_PT=1
686 	 */
687 	spin_lock(&dev->se_port_lock);
688 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
689 		atomic_inc_mb(&port->sep_tg_pt_ref_cnt);
690 		spin_unlock(&dev->se_port_lock);
691 
692 		spin_lock_bh(&port->sep_alua_lock);
693 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
694 					alua_port_list) {
695 			/*
696 			 * This pointer will be NULL for demo mode MappedLUNs
697 			 * that have not been make explicit via a ConfigFS
698 			 * MappedLUN group for the SCSI Initiator Node ACL.
699 			 */
700 			if (!deve_tmp->se_lun_acl)
701 				continue;
702 
703 			nacl_tmp = deve_tmp->se_lun_acl->se_lun_nacl;
704 			/*
705 			 * Skip the matching struct se_node_acl that is allocated
706 			 * above..
707 			 */
708 			if (nacl == nacl_tmp)
709 				continue;
710 			/*
711 			 * Only perform PR registrations for target ports on
712 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
713 			 * arrived.
714 			 */
715 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
716 				continue;
717 			/*
718 			 * Look for a matching Initiator Node ACL in ASCII format
719 			 */
720 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
721 				continue;
722 
723 			atomic_inc_mb(&deve_tmp->pr_ref_count);
724 			spin_unlock_bh(&port->sep_alua_lock);
725 			/*
726 			 * Grab a configfs group dependency that is released
727 			 * for the exception path at label out: below, or upon
728 			 * completion of adding ALL_TG_PT=1 registrations in
729 			 * __core_scsi3_add_registration()
730 			 */
731 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
732 			if (ret < 0) {
733 				pr_err("core_scsi3_lunacl_depend"
734 						"_item() failed\n");
735 				atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
736 				atomic_dec_mb(&deve_tmp->pr_ref_count);
737 				goto out;
738 			}
739 			/*
740 			 * Located a matching SCSI Initiator Port on a different
741 			 * port, allocate the pr_reg_atp and attach it to the
742 			 * pr_reg->pr_reg_atp_list that will be processed once
743 			 * the original *pr_reg is processed in
744 			 * __core_scsi3_add_registration()
745 			 */
746 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
747 						nacl_tmp, deve_tmp, NULL,
748 						sa_res_key, all_tg_pt, aptpl);
749 			if (!pr_reg_atp) {
750 				atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
751 				atomic_dec_mb(&deve_tmp->pr_ref_count);
752 				core_scsi3_lunacl_undepend_item(deve_tmp);
753 				goto out;
754 			}
755 
756 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
757 				      &pr_reg->pr_reg_atp_list);
758 			spin_lock_bh(&port->sep_alua_lock);
759 		}
760 		spin_unlock_bh(&port->sep_alua_lock);
761 
762 		spin_lock(&dev->se_port_lock);
763 		atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
764 	}
765 	spin_unlock(&dev->se_port_lock);
766 
767 	return pr_reg;
768 out:
769 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
770 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
771 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
772 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
773 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
774 	}
775 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
776 	return NULL;
777 }
778 
779 int core_scsi3_alloc_aptpl_registration(
780 	struct t10_reservation *pr_tmpl,
781 	u64 sa_res_key,
782 	unsigned char *i_port,
783 	unsigned char *isid,
784 	u32 mapped_lun,
785 	unsigned char *t_port,
786 	u16 tpgt,
787 	u32 target_lun,
788 	int res_holder,
789 	int all_tg_pt,
790 	u8 type)
791 {
792 	struct t10_pr_registration *pr_reg;
793 
794 	if (!i_port || !t_port || !sa_res_key) {
795 		pr_err("Illegal parameters for APTPL registration\n");
796 		return -EINVAL;
797 	}
798 
799 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
800 	if (!pr_reg) {
801 		pr_err("Unable to allocate struct t10_pr_registration\n");
802 		return -ENOMEM;
803 	}
804 
805 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
806 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
807 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
808 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
809 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
810 	atomic_set(&pr_reg->pr_res_holders, 0);
811 	pr_reg->pr_reg_nacl = NULL;
812 	pr_reg->pr_reg_deve = NULL;
813 	pr_reg->pr_res_mapped_lun = mapped_lun;
814 	pr_reg->pr_aptpl_target_lun = target_lun;
815 	pr_reg->pr_res_key = sa_res_key;
816 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
817 	pr_reg->pr_reg_aptpl = 1;
818 	pr_reg->pr_reg_tg_pt_lun = NULL;
819 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
820 	pr_reg->pr_res_type = type;
821 	/*
822 	 * If an ISID value had been saved in APTPL metadata for this
823 	 * SCSI Initiator Port, restore it now.
824 	 */
825 	if (isid != NULL) {
826 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
827 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
828 		pr_reg->isid_present_at_reg = 1;
829 	}
830 	/*
831 	 * Copy the i_port and t_port information from caller.
832 	 */
833 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
834 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
835 	pr_reg->pr_reg_tpgt = tpgt;
836 	/*
837 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
838 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
839 	 * the Initiator Node LUN ACL from the fabric module is created for
840 	 * this registration.
841 	 */
842 	pr_reg->pr_res_holder = res_holder;
843 
844 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
845 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
846 			" metadata\n", (res_holder) ? "+reservation" : "");
847 	return 0;
848 }
849 
850 static void core_scsi3_aptpl_reserve(
851 	struct se_device *dev,
852 	struct se_portal_group *tpg,
853 	struct se_node_acl *node_acl,
854 	struct t10_pr_registration *pr_reg)
855 {
856 	char i_buf[PR_REG_ISID_ID_LEN];
857 
858 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
859 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
860 
861 	spin_lock(&dev->dev_reservation_lock);
862 	dev->dev_pr_res_holder = pr_reg;
863 	spin_unlock(&dev->dev_reservation_lock);
864 
865 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
866 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
867 		tpg->se_tpg_tfo->get_fabric_name(),
868 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
869 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
870 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
871 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
872 		i_buf);
873 }
874 
875 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
876 				struct t10_pr_registration *, enum register_type, int);
877 
878 static int __core_scsi3_check_aptpl_registration(
879 	struct se_device *dev,
880 	struct se_portal_group *tpg,
881 	struct se_lun *lun,
882 	u32 target_lun,
883 	struct se_node_acl *nacl,
884 	struct se_dev_entry *deve)
885 {
886 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
887 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
888 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
889 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
890 	u16 tpgt;
891 
892 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
893 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
894 	/*
895 	 * Copy Initiator Port information from struct se_node_acl
896 	 */
897 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
898 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
899 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
900 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
901 	/*
902 	 * Look for the matching registrations+reservation from those
903 	 * created from APTPL metadata.  Note that multiple registrations
904 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
905 	 * TransportIDs.
906 	 */
907 	spin_lock(&pr_tmpl->aptpl_reg_lock);
908 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
909 				pr_reg_aptpl_list) {
910 
911 		if (!strcmp(pr_reg->pr_iport, i_port) &&
912 		     (pr_reg->pr_res_mapped_lun == deve->mapped_lun) &&
913 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
914 		     (pr_reg->pr_reg_tpgt == tpgt) &&
915 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
916 
917 			pr_reg->pr_reg_nacl = nacl;
918 			pr_reg->pr_reg_deve = deve;
919 			pr_reg->pr_reg_tg_pt_lun = lun;
920 
921 			list_del(&pr_reg->pr_reg_aptpl_list);
922 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
923 			/*
924 			 * At this point all of the pointers in *pr_reg will
925 			 * be setup, so go ahead and add the registration.
926 			 */
927 
928 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
929 			/*
930 			 * If this registration is the reservation holder,
931 			 * make that happen now..
932 			 */
933 			if (pr_reg->pr_res_holder)
934 				core_scsi3_aptpl_reserve(dev, tpg,
935 						nacl, pr_reg);
936 			/*
937 			 * Reenable pr_aptpl_active to accept new metadata
938 			 * updates once the SCSI device is active again..
939 			 */
940 			spin_lock(&pr_tmpl->aptpl_reg_lock);
941 			pr_tmpl->pr_aptpl_active = 1;
942 		}
943 	}
944 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
945 
946 	return 0;
947 }
948 
949 int core_scsi3_check_aptpl_registration(
950 	struct se_device *dev,
951 	struct se_portal_group *tpg,
952 	struct se_lun *lun,
953 	struct se_node_acl *nacl,
954 	u32 mapped_lun)
955 {
956 	struct se_dev_entry *deve = nacl->device_list[mapped_lun];
957 
958 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
959 		return 0;
960 
961 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
962 				lun->unpacked_lun, nacl, deve);
963 }
964 
965 static void __core_scsi3_dump_registration(
966 	struct target_core_fabric_ops *tfo,
967 	struct se_device *dev,
968 	struct se_node_acl *nacl,
969 	struct t10_pr_registration *pr_reg,
970 	enum register_type register_type)
971 {
972 	struct se_portal_group *se_tpg = nacl->se_tpg;
973 	char i_buf[PR_REG_ISID_ID_LEN];
974 
975 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
976 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
977 
978 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
979 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == REGISTER_AND_MOVE) ?
980 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
981 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
982 		i_buf);
983 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
984 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
985 		tfo->tpg_get_tag(se_tpg));
986 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
987 		" Port(s)\n",  tfo->get_fabric_name(),
988 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
989 		dev->transport->name);
990 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
991 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
992 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
993 		pr_reg->pr_reg_aptpl);
994 }
995 
996 /*
997  * this function can be called with struct se_device->dev_reservation_lock
998  * when register_move = 1
999  */
1000 static void __core_scsi3_add_registration(
1001 	struct se_device *dev,
1002 	struct se_node_acl *nacl,
1003 	struct t10_pr_registration *pr_reg,
1004 	enum register_type register_type,
1005 	int register_move)
1006 {
1007 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1008 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1009 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1010 
1011 	/*
1012 	 * Increment PRgeneration counter for struct se_device upon a successful
1013 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1014 	 *
1015 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1016 	 * action, the struct se_device->dev_reservation_lock will already be held,
1017 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1018 	 * for the REGISTER.
1019 	 */
1020 	pr_reg->pr_res_generation = (register_move) ?
1021 			dev->t10_pr.pr_generation++ :
1022 			core_scsi3_pr_generation(dev);
1023 
1024 	spin_lock(&pr_tmpl->registration_lock);
1025 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1026 	pr_reg->pr_reg_deve->def_pr_registered = 1;
1027 
1028 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1029 	spin_unlock(&pr_tmpl->registration_lock);
1030 	/*
1031 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1032 	 */
1033 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1034 		return;
1035 	/*
1036 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1037 	 * allocated in __core_scsi3_alloc_registration()
1038 	 */
1039 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1040 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1041 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1042 
1043 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1044 
1045 		spin_lock(&pr_tmpl->registration_lock);
1046 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1047 			      &pr_tmpl->registration_list);
1048 		pr_reg_tmp->pr_reg_deve->def_pr_registered = 1;
1049 
1050 		__core_scsi3_dump_registration(tfo, dev,
1051 				pr_reg_tmp->pr_reg_nacl, pr_reg_tmp,
1052 				register_type);
1053 		spin_unlock(&pr_tmpl->registration_lock);
1054 		/*
1055 		 * Drop configfs group dependency reference from
1056 		 * __core_scsi3_alloc_registration()
1057 		 */
1058 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1059 	}
1060 }
1061 
1062 static int core_scsi3_alloc_registration(
1063 	struct se_device *dev,
1064 	struct se_node_acl *nacl,
1065 	struct se_dev_entry *deve,
1066 	unsigned char *isid,
1067 	u64 sa_res_key,
1068 	int all_tg_pt,
1069 	int aptpl,
1070 	enum register_type register_type,
1071 	int register_move)
1072 {
1073 	struct t10_pr_registration *pr_reg;
1074 
1075 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, deve, isid,
1076 			sa_res_key, all_tg_pt, aptpl);
1077 	if (!pr_reg)
1078 		return -EPERM;
1079 
1080 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1081 			register_type, register_move);
1082 	return 0;
1083 }
1084 
1085 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1086 	struct se_device *dev,
1087 	struct se_node_acl *nacl,
1088 	unsigned char *isid)
1089 {
1090 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1091 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1092 	struct se_portal_group *tpg;
1093 
1094 	spin_lock(&pr_tmpl->registration_lock);
1095 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1096 			&pr_tmpl->registration_list, pr_reg_list) {
1097 		/*
1098 		 * First look for a matching struct se_node_acl
1099 		 */
1100 		if (pr_reg->pr_reg_nacl != nacl)
1101 			continue;
1102 
1103 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1104 		/*
1105 		 * If this registration does NOT contain a fabric provided
1106 		 * ISID, then we have found a match.
1107 		 */
1108 		if (!pr_reg->isid_present_at_reg) {
1109 			/*
1110 			 * Determine if this SCSI device server requires that
1111 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1112 			 * for fabric modules (iSCSI) requiring them.
1113 			 */
1114 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1115 				if (dev->dev_attrib.enforce_pr_isids)
1116 					continue;
1117 			}
1118 			atomic_inc_mb(&pr_reg->pr_res_holders);
1119 			spin_unlock(&pr_tmpl->registration_lock);
1120 			return pr_reg;
1121 		}
1122 		/*
1123 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1124 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1125 		 * matching ISID to be provided by the local SCSI Initiator Port.
1126 		 */
1127 		if (!isid)
1128 			continue;
1129 		if (strcmp(isid, pr_reg->pr_reg_isid))
1130 			continue;
1131 
1132 		atomic_inc_mb(&pr_reg->pr_res_holders);
1133 		spin_unlock(&pr_tmpl->registration_lock);
1134 		return pr_reg;
1135 	}
1136 	spin_unlock(&pr_tmpl->registration_lock);
1137 
1138 	return NULL;
1139 }
1140 
1141 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1142 	struct se_device *dev,
1143 	struct se_node_acl *nacl,
1144 	struct se_session *sess)
1145 {
1146 	struct se_portal_group *tpg = nacl->se_tpg;
1147 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1148 
1149 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1150 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1151 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1152 					PR_REG_ISID_LEN);
1153 		isid_ptr = &buf[0];
1154 	}
1155 
1156 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1157 }
1158 
1159 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1160 {
1161 	atomic_dec_mb(&pr_reg->pr_res_holders);
1162 }
1163 
1164 static int core_scsi3_check_implicit_release(
1165 	struct se_device *dev,
1166 	struct t10_pr_registration *pr_reg)
1167 {
1168 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1169 	struct t10_pr_registration *pr_res_holder;
1170 	int ret = 0;
1171 
1172 	spin_lock(&dev->dev_reservation_lock);
1173 	pr_res_holder = dev->dev_pr_res_holder;
1174 	if (!pr_res_holder) {
1175 		spin_unlock(&dev->dev_reservation_lock);
1176 		return ret;
1177 	}
1178 	if (pr_res_holder == pr_reg) {
1179 		/*
1180 		 * Perform an implicit RELEASE if the registration that
1181 		 * is being released is holding the reservation.
1182 		 *
1183 		 * From spc4r17, section 5.7.11.1:
1184 		 *
1185 		 * e) If the I_T nexus is the persistent reservation holder
1186 		 *    and the persistent reservation is not an all registrants
1187 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1188 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1189 		 *    service action with the SERVICE ACTION RESERVATION KEY
1190 		 *    field set to zero (see 5.7.11.3).
1191 		 */
1192 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1193 		ret = 1;
1194 		/*
1195 		 * For 'All Registrants' reservation types, all existing
1196 		 * registrations are still processed as reservation holders
1197 		 * in core_scsi3_pr_seq_non_holder() after the initial
1198 		 * reservation holder is implicitly released here.
1199 		 */
1200 	} else if (pr_reg->pr_reg_all_tg_pt &&
1201 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1202 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1203 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1204 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1205 			" UNREGISTER while existing reservation with matching"
1206 			" key 0x%016Lx is present from another SCSI Initiator"
1207 			" Port\n", pr_reg->pr_res_key);
1208 		ret = -EPERM;
1209 	}
1210 	spin_unlock(&dev->dev_reservation_lock);
1211 
1212 	return ret;
1213 }
1214 
1215 /*
1216  * Called with struct t10_reservation->registration_lock held.
1217  */
1218 static void __core_scsi3_free_registration(
1219 	struct se_device *dev,
1220 	struct t10_pr_registration *pr_reg,
1221 	struct list_head *preempt_and_abort_list,
1222 	int dec_holders)
1223 {
1224 	struct target_core_fabric_ops *tfo =
1225 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1226 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1227 	char i_buf[PR_REG_ISID_ID_LEN];
1228 
1229 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1230 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1231 
1232 	pr_reg->pr_reg_deve->def_pr_registered = 0;
1233 	pr_reg->pr_reg_deve->pr_res_key = 0;
1234 	if (!list_empty(&pr_reg->pr_reg_list))
1235 		list_del(&pr_reg->pr_reg_list);
1236 	/*
1237 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1238 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1239 	 */
1240 	if (dec_holders)
1241 		core_scsi3_put_pr_reg(pr_reg);
1242 	/*
1243 	 * Wait until all reference from any other I_T nexuses for this
1244 	 * *pr_reg have been released.  Because list_del() is called above,
1245 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1246 	 * count back to zero, and we release *pr_reg.
1247 	 */
1248 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1249 		spin_unlock(&pr_tmpl->registration_lock);
1250 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1251 				tfo->get_fabric_name());
1252 		cpu_relax();
1253 		spin_lock(&pr_tmpl->registration_lock);
1254 	}
1255 
1256 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1257 		" Node: %s%s\n", tfo->get_fabric_name(),
1258 		pr_reg->pr_reg_nacl->initiatorname,
1259 		i_buf);
1260 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1261 		" Port(s)\n", tfo->get_fabric_name(),
1262 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1263 		dev->transport->name);
1264 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1265 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1266 		pr_reg->pr_res_generation);
1267 
1268 	if (!preempt_and_abort_list) {
1269 		pr_reg->pr_reg_deve = NULL;
1270 		pr_reg->pr_reg_nacl = NULL;
1271 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1272 		return;
1273 	}
1274 	/*
1275 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1276 	 * are released once the ABORT_TASK_SET has completed..
1277 	 */
1278 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1279 }
1280 
1281 void core_scsi3_free_pr_reg_from_nacl(
1282 	struct se_device *dev,
1283 	struct se_node_acl *nacl)
1284 {
1285 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1286 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1287 	bool free_reg = false;
1288 	/*
1289 	 * If the passed se_node_acl matches the reservation holder,
1290 	 * release the reservation.
1291 	 */
1292 	spin_lock(&dev->dev_reservation_lock);
1293 	pr_res_holder = dev->dev_pr_res_holder;
1294 	if ((pr_res_holder != NULL) &&
1295 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1296 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1297 		free_reg = true;
1298 	}
1299 	spin_unlock(&dev->dev_reservation_lock);
1300 	/*
1301 	 * Release any registration associated with the struct se_node_acl.
1302 	 */
1303 	spin_lock(&pr_tmpl->registration_lock);
1304 	if (pr_res_holder && free_reg)
1305 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1306 
1307 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1308 			&pr_tmpl->registration_list, pr_reg_list) {
1309 
1310 		if (pr_reg->pr_reg_nacl != nacl)
1311 			continue;
1312 
1313 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1314 	}
1315 	spin_unlock(&pr_tmpl->registration_lock);
1316 }
1317 
1318 void core_scsi3_free_all_registrations(
1319 	struct se_device *dev)
1320 {
1321 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1322 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1323 
1324 	spin_lock(&dev->dev_reservation_lock);
1325 	pr_res_holder = dev->dev_pr_res_holder;
1326 	if (pr_res_holder != NULL) {
1327 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1328 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1329 						  pr_res_holder, 0, 0);
1330 	}
1331 	spin_unlock(&dev->dev_reservation_lock);
1332 
1333 	spin_lock(&pr_tmpl->registration_lock);
1334 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1335 			&pr_tmpl->registration_list, pr_reg_list) {
1336 
1337 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1338 	}
1339 	spin_unlock(&pr_tmpl->registration_lock);
1340 
1341 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1342 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1343 				pr_reg_aptpl_list) {
1344 		list_del(&pr_reg->pr_reg_aptpl_list);
1345 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1346 	}
1347 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1348 }
1349 
1350 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1351 {
1352 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1353 			&tpg->tpg_group.cg_item);
1354 }
1355 
1356 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1357 {
1358 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1359 			&tpg->tpg_group.cg_item);
1360 
1361 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1362 }
1363 
1364 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1365 {
1366 	struct se_portal_group *tpg = nacl->se_tpg;
1367 
1368 	if (nacl->dynamic_node_acl)
1369 		return 0;
1370 
1371 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1372 			&nacl->acl_group.cg_item);
1373 }
1374 
1375 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1376 {
1377 	struct se_portal_group *tpg = nacl->se_tpg;
1378 
1379 	if (nacl->dynamic_node_acl) {
1380 		atomic_dec_mb(&nacl->acl_pr_ref_count);
1381 		return;
1382 	}
1383 
1384 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1385 			&nacl->acl_group.cg_item);
1386 
1387 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1388 }
1389 
1390 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1391 {
1392 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1393 	struct se_node_acl *nacl;
1394 	struct se_portal_group *tpg;
1395 	/*
1396 	 * For nacl->dynamic_node_acl=1
1397 	 */
1398 	if (!lun_acl)
1399 		return 0;
1400 
1401 	nacl = lun_acl->se_lun_nacl;
1402 	tpg = nacl->se_tpg;
1403 
1404 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1405 			&lun_acl->se_lun_group.cg_item);
1406 }
1407 
1408 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1409 {
1410 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1411 	struct se_node_acl *nacl;
1412 	struct se_portal_group *tpg;
1413 	/*
1414 	 * For nacl->dynamic_node_acl=1
1415 	 */
1416 	if (!lun_acl) {
1417 		atomic_dec_mb(&se_deve->pr_ref_count);
1418 		return;
1419 	}
1420 	nacl = lun_acl->se_lun_nacl;
1421 	tpg = nacl->se_tpg;
1422 
1423 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1424 			&lun_acl->se_lun_group.cg_item);
1425 
1426 	atomic_dec_mb(&se_deve->pr_ref_count);
1427 }
1428 
1429 static sense_reason_t
1430 core_scsi3_decode_spec_i_port(
1431 	struct se_cmd *cmd,
1432 	struct se_portal_group *tpg,
1433 	unsigned char *l_isid,
1434 	u64 sa_res_key,
1435 	int all_tg_pt,
1436 	int aptpl)
1437 {
1438 	struct se_device *dev = cmd->se_dev;
1439 	struct se_port *tmp_port;
1440 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1441 	struct se_session *se_sess = cmd->se_sess;
1442 	struct se_node_acl *dest_node_acl = NULL;
1443 	struct se_dev_entry *dest_se_deve = NULL, *local_se_deve;
1444 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1445 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1446 	LIST_HEAD(tid_dest_list);
1447 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1448 	struct target_core_fabric_ops *tmp_tf_ops;
1449 	unsigned char *buf;
1450 	unsigned char *ptr, *i_str = NULL, proto_ident, tmp_proto_ident;
1451 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1452 	sense_reason_t ret;
1453 	u32 tpdl, tid_len = 0;
1454 	int dest_local_nexus;
1455 	u32 dest_rtpi = 0;
1456 
1457 	local_se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
1458 	/*
1459 	 * Allocate a struct pr_transport_id_holder and setup the
1460 	 * local_node_acl and local_se_deve pointers and add to
1461 	 * struct list_head tid_dest_list for add registration
1462 	 * processing in the loop of tid_dest_list below.
1463 	 */
1464 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1465 	if (!tidh_new) {
1466 		pr_err("Unable to allocate tidh_new\n");
1467 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1468 	}
1469 	INIT_LIST_HEAD(&tidh_new->dest_list);
1470 	tidh_new->dest_tpg = tpg;
1471 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1472 	tidh_new->dest_se_deve = local_se_deve;
1473 
1474 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1475 				se_sess->se_node_acl, local_se_deve, l_isid,
1476 				sa_res_key, all_tg_pt, aptpl);
1477 	if (!local_pr_reg) {
1478 		kfree(tidh_new);
1479 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1480 	}
1481 	tidh_new->dest_pr_reg = local_pr_reg;
1482 	/*
1483 	 * The local I_T nexus does not hold any configfs dependances,
1484 	 * so we set tid_h->dest_local_nexus=1 to prevent the
1485 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1486 	 */
1487 	tidh_new->dest_local_nexus = 1;
1488 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1489 
1490 	if (cmd->data_length < 28) {
1491 		pr_warn("SPC-PR: Received PR OUT parameter list"
1492 			" length too small: %u\n", cmd->data_length);
1493 		ret = TCM_INVALID_PARAMETER_LIST;
1494 		goto out;
1495 	}
1496 
1497 	buf = transport_kmap_data_sg(cmd);
1498 	if (!buf) {
1499 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1500 		goto out;
1501 	}
1502 
1503 	/*
1504 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1505 	 * first extract TransportID Parameter Data Length, and make sure
1506 	 * the value matches up to the SCSI expected data transfer length.
1507 	 */
1508 	tpdl = (buf[24] & 0xff) << 24;
1509 	tpdl |= (buf[25] & 0xff) << 16;
1510 	tpdl |= (buf[26] & 0xff) << 8;
1511 	tpdl |= buf[27] & 0xff;
1512 
1513 	if ((tpdl + 28) != cmd->data_length) {
1514 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1515 			" does not equal CDB data_length: %u\n", tpdl,
1516 			cmd->data_length);
1517 		ret = TCM_INVALID_PARAMETER_LIST;
1518 		goto out_unmap;
1519 	}
1520 	/*
1521 	 * Start processing the received transport IDs using the
1522 	 * receiving I_T Nexus portal's fabric dependent methods to
1523 	 * obtain the SCSI Initiator Port/Device Identifiers.
1524 	 */
1525 	ptr = &buf[28];
1526 
1527 	while (tpdl > 0) {
1528 		proto_ident = (ptr[0] & 0x0f);
1529 		dest_tpg = NULL;
1530 
1531 		spin_lock(&dev->se_port_lock);
1532 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1533 			tmp_tpg = tmp_port->sep_tpg;
1534 			if (!tmp_tpg)
1535 				continue;
1536 			tmp_tf_ops = tmp_tpg->se_tpg_tfo;
1537 			if (!tmp_tf_ops)
1538 				continue;
1539 			if (!tmp_tf_ops->get_fabric_proto_ident ||
1540 			    !tmp_tf_ops->tpg_parse_pr_out_transport_id)
1541 				continue;
1542 			/*
1543 			 * Look for the matching proto_ident provided by
1544 			 * the received TransportID
1545 			 */
1546 			tmp_proto_ident = tmp_tf_ops->get_fabric_proto_ident(tmp_tpg);
1547 			if (tmp_proto_ident != proto_ident)
1548 				continue;
1549 			dest_rtpi = tmp_port->sep_rtpi;
1550 
1551 			i_str = tmp_tf_ops->tpg_parse_pr_out_transport_id(
1552 					tmp_tpg, (const char *)ptr, &tid_len,
1553 					&iport_ptr);
1554 			if (!i_str)
1555 				continue;
1556 
1557 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1558 			spin_unlock(&dev->se_port_lock);
1559 
1560 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1561 				pr_err(" core_scsi3_tpg_depend_item()"
1562 					" for tmp_tpg\n");
1563 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1564 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1565 				goto out_unmap;
1566 			}
1567 			/*
1568 			 * Locate the destination initiator ACL to be registered
1569 			 * from the decoded fabric module specific TransportID
1570 			 * at *i_str.
1571 			 */
1572 			spin_lock_irq(&tmp_tpg->acl_node_lock);
1573 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1574 						tmp_tpg, i_str);
1575 			if (dest_node_acl)
1576 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1577 			spin_unlock_irq(&tmp_tpg->acl_node_lock);
1578 
1579 			if (!dest_node_acl) {
1580 				core_scsi3_tpg_undepend_item(tmp_tpg);
1581 				spin_lock(&dev->se_port_lock);
1582 				continue;
1583 			}
1584 
1585 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1586 				pr_err("configfs_depend_item() failed"
1587 					" for dest_node_acl->acl_group\n");
1588 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1589 				core_scsi3_tpg_undepend_item(tmp_tpg);
1590 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1591 				goto out_unmap;
1592 			}
1593 
1594 			dest_tpg = tmp_tpg;
1595 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1596 				" %s Port RTPI: %hu\n",
1597 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1598 				dest_node_acl->initiatorname, dest_rtpi);
1599 
1600 			spin_lock(&dev->se_port_lock);
1601 			break;
1602 		}
1603 		spin_unlock(&dev->se_port_lock);
1604 
1605 		if (!dest_tpg) {
1606 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1607 					" dest_tpg\n");
1608 			ret = TCM_INVALID_PARAMETER_LIST;
1609 			goto out_unmap;
1610 		}
1611 
1612 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1613 			" tid_len: %d for %s + %s\n",
1614 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1615 			tpdl, tid_len, i_str, iport_ptr);
1616 
1617 		if (tid_len > tpdl) {
1618 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1619 				" %u for Transport ID: %s\n", tid_len, ptr);
1620 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1621 			core_scsi3_tpg_undepend_item(dest_tpg);
1622 			ret = TCM_INVALID_PARAMETER_LIST;
1623 			goto out_unmap;
1624 		}
1625 		/*
1626 		 * Locate the desintation struct se_dev_entry pointer for matching
1627 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1628 		 * Target Port.
1629 		 */
1630 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1631 					dest_rtpi);
1632 		if (!dest_se_deve) {
1633 			pr_err("Unable to locate %s dest_se_deve"
1634 				" from destination RTPI: %hu\n",
1635 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1636 				dest_rtpi);
1637 
1638 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1639 			core_scsi3_tpg_undepend_item(dest_tpg);
1640 			ret = TCM_INVALID_PARAMETER_LIST;
1641 			goto out_unmap;
1642 		}
1643 
1644 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1645 			pr_err("core_scsi3_lunacl_depend_item()"
1646 					" failed\n");
1647 			atomic_dec_mb(&dest_se_deve->pr_ref_count);
1648 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1649 			core_scsi3_tpg_undepend_item(dest_tpg);
1650 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1651 			goto out_unmap;
1652 		}
1653 
1654 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1655 			" dest_se_deve mapped_lun: %u\n",
1656 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1657 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1658 
1659 		/*
1660 		 * Skip any TransportIDs that already have a registration for
1661 		 * this target port.
1662 		 */
1663 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1664 					iport_ptr);
1665 		if (pr_reg_e) {
1666 			core_scsi3_put_pr_reg(pr_reg_e);
1667 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1668 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1669 			core_scsi3_tpg_undepend_item(dest_tpg);
1670 			ptr += tid_len;
1671 			tpdl -= tid_len;
1672 			tid_len = 0;
1673 			continue;
1674 		}
1675 		/*
1676 		 * Allocate a struct pr_transport_id_holder and setup
1677 		 * the dest_node_acl and dest_se_deve pointers for the
1678 		 * loop below.
1679 		 */
1680 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1681 				GFP_KERNEL);
1682 		if (!tidh_new) {
1683 			pr_err("Unable to allocate tidh_new\n");
1684 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1685 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1686 			core_scsi3_tpg_undepend_item(dest_tpg);
1687 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1688 			goto out_unmap;
1689 		}
1690 		INIT_LIST_HEAD(&tidh_new->dest_list);
1691 		tidh_new->dest_tpg = dest_tpg;
1692 		tidh_new->dest_node_acl = dest_node_acl;
1693 		tidh_new->dest_se_deve = dest_se_deve;
1694 
1695 		/*
1696 		 * Allocate, but do NOT add the registration for the
1697 		 * TransportID referenced SCSI Initiator port.  This
1698 		 * done because of the following from spc4r17 in section
1699 		 * 6.14.3 wrt SPEC_I_PT:
1700 		 *
1701 		 * "If a registration fails for any initiator port (e.g., if th
1702 		 * logical unit does not have enough resources available to
1703 		 * hold the registration information), no registrations shall be
1704 		 * made, and the command shall be terminated with
1705 		 * CHECK CONDITION status."
1706 		 *
1707 		 * That means we call __core_scsi3_alloc_registration() here,
1708 		 * and then call __core_scsi3_add_registration() in the
1709 		 * 2nd loop which will never fail.
1710 		 */
1711 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1712 				dest_node_acl, dest_se_deve, iport_ptr,
1713 				sa_res_key, all_tg_pt, aptpl);
1714 		if (!dest_pr_reg) {
1715 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1716 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1717 			core_scsi3_tpg_undepend_item(dest_tpg);
1718 			kfree(tidh_new);
1719 			ret = TCM_INVALID_PARAMETER_LIST;
1720 			goto out_unmap;
1721 		}
1722 		tidh_new->dest_pr_reg = dest_pr_reg;
1723 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1724 
1725 		ptr += tid_len;
1726 		tpdl -= tid_len;
1727 		tid_len = 0;
1728 
1729 	}
1730 
1731 	transport_kunmap_data_sg(cmd);
1732 
1733 	/*
1734 	 * Go ahead and create a registrations from tid_dest_list for the
1735 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1736 	 * and dest_se_deve.
1737 	 *
1738 	 * The SA Reservation Key from the PROUT is set for the
1739 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1740 	 * means that the TransportID Initiator port will be
1741 	 * registered on all of the target ports in the SCSI target device
1742 	 * ALL_TG_PT=0 means the registration will only be for the
1743 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1744 	 * was received.
1745 	 */
1746 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1747 		dest_tpg = tidh->dest_tpg;
1748 		dest_node_acl = tidh->dest_node_acl;
1749 		dest_se_deve = tidh->dest_se_deve;
1750 		dest_pr_reg = tidh->dest_pr_reg;
1751 		dest_local_nexus = tidh->dest_local_nexus;
1752 
1753 		list_del(&tidh->dest_list);
1754 		kfree(tidh);
1755 
1756 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1757 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1758 
1759 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1760 					dest_pr_reg, 0, 0);
1761 
1762 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1763 			" registered Transport ID for Node: %s%s Mapped LUN:"
1764 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1765 			dest_node_acl->initiatorname, i_buf, dest_se_deve->mapped_lun);
1766 
1767 		if (dest_local_nexus)
1768 			continue;
1769 
1770 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1771 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1772 		core_scsi3_tpg_undepend_item(dest_tpg);
1773 	}
1774 
1775 	return 0;
1776 out_unmap:
1777 	transport_kunmap_data_sg(cmd);
1778 out:
1779 	/*
1780 	 * For the failure case, release everything from tid_dest_list
1781 	 * including *dest_pr_reg and the configfs dependances..
1782 	 */
1783 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1784 		dest_tpg = tidh->dest_tpg;
1785 		dest_node_acl = tidh->dest_node_acl;
1786 		dest_se_deve = tidh->dest_se_deve;
1787 		dest_pr_reg = tidh->dest_pr_reg;
1788 		dest_local_nexus = tidh->dest_local_nexus;
1789 
1790 		list_del(&tidh->dest_list);
1791 		kfree(tidh);
1792 		/*
1793 		 * Release any extra ALL_TG_PT=1 registrations for
1794 		 * the SPEC_I_PT=1 case.
1795 		 */
1796 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1797 				&dest_pr_reg->pr_reg_atp_list,
1798 				pr_reg_atp_mem_list) {
1799 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1800 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1801 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1802 		}
1803 
1804 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1805 
1806 		if (dest_local_nexus)
1807 			continue;
1808 
1809 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1810 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1811 		core_scsi3_tpg_undepend_item(dest_tpg);
1812 	}
1813 	return ret;
1814 }
1815 
1816 static int core_scsi3_update_aptpl_buf(
1817 	struct se_device *dev,
1818 	unsigned char *buf,
1819 	u32 pr_aptpl_buf_len)
1820 {
1821 	struct se_lun *lun;
1822 	struct se_portal_group *tpg;
1823 	struct t10_pr_registration *pr_reg;
1824 	unsigned char tmp[512], isid_buf[32];
1825 	ssize_t len = 0;
1826 	int reg_count = 0;
1827 	int ret = 0;
1828 
1829 	spin_lock(&dev->dev_reservation_lock);
1830 	spin_lock(&dev->t10_pr.registration_lock);
1831 	/*
1832 	 * Walk the registration list..
1833 	 */
1834 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1835 			pr_reg_list) {
1836 
1837 		tmp[0] = '\0';
1838 		isid_buf[0] = '\0';
1839 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1840 		lun = pr_reg->pr_reg_tg_pt_lun;
1841 		/*
1842 		 * Write out any ISID value to APTPL metadata that was included
1843 		 * in the original registration.
1844 		 */
1845 		if (pr_reg->isid_present_at_reg)
1846 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1847 					pr_reg->pr_reg_isid);
1848 		/*
1849 		 * Include special metadata if the pr_reg matches the
1850 		 * reservation holder.
1851 		 */
1852 		if (dev->dev_pr_res_holder == pr_reg) {
1853 			snprintf(tmp, 512, "PR_REG_START: %d"
1854 				"\ninitiator_fabric=%s\n"
1855 				"initiator_node=%s\n%s"
1856 				"sa_res_key=%llu\n"
1857 				"res_holder=1\nres_type=%02x\n"
1858 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1859 				"mapped_lun=%u\n", reg_count,
1860 				tpg->se_tpg_tfo->get_fabric_name(),
1861 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1862 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1863 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1864 				pr_reg->pr_res_mapped_lun);
1865 		} else {
1866 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1867 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1868 				"sa_res_key=%llu\nres_holder=0\n"
1869 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1870 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1871 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1872 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1873 				pr_reg->pr_res_mapped_lun);
1874 		}
1875 
1876 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1877 			pr_err("Unable to update renaming APTPL metadata,"
1878 			       " reallocating larger buffer\n");
1879 			ret = -EMSGSIZE;
1880 			goto out;
1881 		}
1882 		len += sprintf(buf+len, "%s", tmp);
1883 
1884 		/*
1885 		 * Include information about the associated SCSI target port.
1886 		 */
1887 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1888 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1889 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1890 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1891 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1892 			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);
1893 
1894 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1895 			pr_err("Unable to update renaming APTPL metadata,"
1896 			       " reallocating larger buffer\n");
1897 			ret = -EMSGSIZE;
1898 			goto out;
1899 		}
1900 		len += sprintf(buf+len, "%s", tmp);
1901 		reg_count++;
1902 	}
1903 
1904 	if (!reg_count)
1905 		len += sprintf(buf+len, "No Registrations or Reservations");
1906 
1907 out:
1908 	spin_unlock(&dev->t10_pr.registration_lock);
1909 	spin_unlock(&dev->dev_reservation_lock);
1910 
1911 	return ret;
1912 }
1913 
1914 static int __core_scsi3_write_aptpl_to_file(
1915 	struct se_device *dev,
1916 	unsigned char *buf)
1917 {
1918 	struct t10_wwn *wwn = &dev->t10_wwn;
1919 	struct file *file;
1920 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1921 	char path[512];
1922 	u32 pr_aptpl_buf_len;
1923 	int ret;
1924 
1925 	memset(path, 0, 512);
1926 
1927 	if (strlen(&wwn->unit_serial[0]) >= 512) {
1928 		pr_err("WWN value for struct se_device does not fit"
1929 			" into path buffer\n");
1930 		return -EMSGSIZE;
1931 	}
1932 
1933 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
1934 	file = filp_open(path, flags, 0600);
1935 	if (IS_ERR(file)) {
1936 		pr_err("filp_open(%s) for APTPL metadata"
1937 			" failed\n", path);
1938 		return PTR_ERR(file);
1939 	}
1940 
1941 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1942 
1943 	ret = kernel_write(file, buf, pr_aptpl_buf_len, 0);
1944 
1945 	if (ret < 0)
1946 		pr_debug("Error writing APTPL metadata file: %s\n", path);
1947 	fput(file);
1948 
1949 	return (ret < 0) ? -EIO : 0;
1950 }
1951 
1952 /*
1953  * Clear the APTPL metadata if APTPL has been disabled, otherwise
1954  * write out the updated metadata to struct file for this SCSI device.
1955  */
1956 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
1957 {
1958 	unsigned char *buf;
1959 	int rc, len = PR_APTPL_BUF_LEN;
1960 
1961 	if (!aptpl) {
1962 		char *null_buf = "No Registrations or Reservations\n";
1963 
1964 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
1965 		dev->t10_pr.pr_aptpl_active = 0;
1966 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
1967 
1968 		if (rc)
1969 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1970 
1971 		return 0;
1972 	}
1973 retry:
1974 	buf = vzalloc(len);
1975 	if (!buf)
1976 		return TCM_OUT_OF_RESOURCES;
1977 
1978 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
1979 	if (rc < 0) {
1980 		vfree(buf);
1981 		len *= 2;
1982 		goto retry;
1983 	}
1984 
1985 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
1986 	if (rc != 0) {
1987 		pr_err("SPC-3 PR: Could not update APTPL\n");
1988 		vfree(buf);
1989 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1990 	}
1991 	dev->t10_pr.pr_aptpl_active = 1;
1992 	vfree(buf);
1993 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
1994 	return 0;
1995 }
1996 
1997 static sense_reason_t
1998 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
1999 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2000 {
2001 	struct se_session *se_sess = cmd->se_sess;
2002 	struct se_device *dev = cmd->se_dev;
2003 	struct se_dev_entry *se_deve;
2004 	struct se_lun *se_lun = cmd->se_lun;
2005 	struct se_portal_group *se_tpg;
2006 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2007 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2008 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2009 	sense_reason_t ret = TCM_NO_SENSE;
2010 	int pr_holder = 0, type;
2011 
2012 	if (!se_sess || !se_lun) {
2013 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2014 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2015 	}
2016 	se_tpg = se_sess->se_tpg;
2017 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2018 
2019 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2020 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2021 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2022 				PR_REG_ISID_LEN);
2023 		isid_ptr = &isid_buf[0];
2024 	}
2025 	/*
2026 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2027 	 */
2028 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2029 	if (!pr_reg) {
2030 		if (res_key) {
2031 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2032 				" for SA REGISTER, returning CONFLICT\n");
2033 			return TCM_RESERVATION_CONFLICT;
2034 		}
2035 		/*
2036 		 * Do nothing but return GOOD status.
2037 		 */
2038 		if (!sa_res_key)
2039 			return 0;
2040 
2041 		if (!spec_i_pt) {
2042 			/*
2043 			 * Perform the Service Action REGISTER on the Initiator
2044 			 * Port Endpoint that the PRO was received from on the
2045 			 * Logical Unit of the SCSI device server.
2046 			 */
2047 			if (core_scsi3_alloc_registration(cmd->se_dev,
2048 					se_sess->se_node_acl, se_deve, isid_ptr,
2049 					sa_res_key, all_tg_pt, aptpl,
2050 					register_type, 0)) {
2051 				pr_err("Unable to allocate"
2052 					" struct t10_pr_registration\n");
2053 				return TCM_INVALID_PARAMETER_LIST;
2054 			}
2055 		} else {
2056 			/*
2057 			 * Register both the Initiator port that received
2058 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2059 			 * TransportID from Parameter list and loop through
2060 			 * fabric dependent parameter list while calling
2061 			 * logic from of core_scsi3_alloc_registration() for
2062 			 * each TransportID provided SCSI Initiator Port/Device
2063 			 */
2064 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2065 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2066 			if (ret != 0)
2067 				return ret;
2068 		}
2069 
2070 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2071 	}
2072 
2073 	/* ok, existing registration */
2074 
2075 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2076 		pr_err("SPC-3 PR REGISTER: Received"
2077 		       " res_key: 0x%016Lx does not match"
2078 		       " existing SA REGISTER res_key:"
2079 		       " 0x%016Lx\n", res_key,
2080 		       pr_reg->pr_res_key);
2081 		ret = TCM_RESERVATION_CONFLICT;
2082 		goto out;
2083 	}
2084 
2085 	if (spec_i_pt) {
2086 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2087 			" set on a registered nexus\n");
2088 		ret = TCM_INVALID_PARAMETER_LIST;
2089 		goto out;
2090 	}
2091 
2092 	/*
2093 	 * An existing ALL_TG_PT=1 registration being released
2094 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2095 	 */
2096 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2097 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2098 			" registration exists, but ALL_TG_PT=1 bit not"
2099 			" present in received PROUT\n");
2100 		ret = TCM_INVALID_CDB_FIELD;
2101 		goto out;
2102 	}
2103 
2104 	/*
2105 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2106 	 */
2107 	if (sa_res_key) {
2108 		/*
2109 		 * Increment PRgeneration counter for struct se_device"
2110 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2111 		 * READ_KEYS service action.
2112 		 */
2113 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2114 		pr_reg->pr_res_key = sa_res_key;
2115 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2116 			 " Key for %s to: 0x%016Lx PRgeneration:"
2117 			 " 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2118 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2119 			 pr_reg->pr_reg_nacl->initiatorname,
2120 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2121 
2122 	} else {
2123 		/*
2124 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2125 		 */
2126 		type = pr_reg->pr_res_type;
2127 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2128 							      pr_reg);
2129 		if (pr_holder < 0) {
2130 			ret = TCM_RESERVATION_CONFLICT;
2131 			goto out;
2132 		}
2133 
2134 		spin_lock(&pr_tmpl->registration_lock);
2135 		/*
2136 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2137 		 * and matching pr_res_key.
2138 		 */
2139 		if (pr_reg->pr_reg_all_tg_pt) {
2140 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2141 					&pr_tmpl->registration_list,
2142 					pr_reg_list) {
2143 
2144 				if (!pr_reg_p->pr_reg_all_tg_pt)
2145 					continue;
2146 				if (pr_reg_p->pr_res_key != res_key)
2147 					continue;
2148 				if (pr_reg == pr_reg_p)
2149 					continue;
2150 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2151 					   pr_reg_p->pr_reg_nacl->initiatorname))
2152 					continue;
2153 
2154 				__core_scsi3_free_registration(dev,
2155 						pr_reg_p, NULL, 0);
2156 			}
2157 		}
2158 
2159 		/*
2160 		 * Release the calling I_T Nexus registration now..
2161 		 */
2162 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2163 		pr_reg = NULL;
2164 
2165 		/*
2166 		 * From spc4r17, section 5.7.11.3 Unregistering
2167 		 *
2168 		 * If the persistent reservation is a registrants only
2169 		 * type, the device server shall establish a unit
2170 		 * attention condition for the initiator port associated
2171 		 * with every registered I_T nexus except for the I_T
2172 		 * nexus on which the PERSISTENT RESERVE OUT command was
2173 		 * received, with the additional sense code set to
2174 		 * RESERVATIONS RELEASED.
2175 		 */
2176 		if (pr_holder &&
2177 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2178 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2179 			list_for_each_entry(pr_reg_p,
2180 					&pr_tmpl->registration_list,
2181 					pr_reg_list) {
2182 
2183 				core_scsi3_ua_allocate(
2184 					pr_reg_p->pr_reg_nacl,
2185 					pr_reg_p->pr_res_mapped_lun,
2186 					0x2A,
2187 					ASCQ_2AH_RESERVATIONS_RELEASED);
2188 			}
2189 		}
2190 
2191 		spin_unlock(&pr_tmpl->registration_lock);
2192 	}
2193 
2194 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2195 
2196 out:
2197 	if (pr_reg)
2198 		core_scsi3_put_pr_reg(pr_reg);
2199 	return ret;
2200 }
2201 
2202 unsigned char *core_scsi3_pr_dump_type(int type)
2203 {
2204 	switch (type) {
2205 	case PR_TYPE_WRITE_EXCLUSIVE:
2206 		return "Write Exclusive Access";
2207 	case PR_TYPE_EXCLUSIVE_ACCESS:
2208 		return "Exclusive Access";
2209 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2210 		return "Write Exclusive Access, Registrants Only";
2211 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2212 		return "Exclusive Access, Registrants Only";
2213 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2214 		return "Write Exclusive Access, All Registrants";
2215 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2216 		return "Exclusive Access, All Registrants";
2217 	default:
2218 		break;
2219 	}
2220 
2221 	return "Unknown SPC-3 PR Type";
2222 }
2223 
2224 static sense_reason_t
2225 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2226 {
2227 	struct se_device *dev = cmd->se_dev;
2228 	struct se_session *se_sess = cmd->se_sess;
2229 	struct se_lun *se_lun = cmd->se_lun;
2230 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2231 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2232 	char i_buf[PR_REG_ISID_ID_LEN];
2233 	sense_reason_t ret;
2234 
2235 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2236 
2237 	if (!se_sess || !se_lun) {
2238 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2239 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2240 	}
2241 	/*
2242 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2243 	 */
2244 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2245 				se_sess);
2246 	if (!pr_reg) {
2247 		pr_err("SPC-3 PR: Unable to locate"
2248 			" PR_REGISTERED *pr_reg for RESERVE\n");
2249 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2250 	}
2251 	/*
2252 	 * From spc4r17 Section 5.7.9: Reserving:
2253 	 *
2254 	 * An application client creates a persistent reservation by issuing
2255 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2256 	 * a registered I_T nexus with the following parameters:
2257 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2258 	 * 	 registered with the logical unit for the I_T nexus; and
2259 	 */
2260 	if (res_key != pr_reg->pr_res_key) {
2261 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2262 			" does not match existing SA REGISTER res_key:"
2263 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2264 		ret = TCM_RESERVATION_CONFLICT;
2265 		goto out_put_pr_reg;
2266 	}
2267 	/*
2268 	 * From spc4r17 Section 5.7.9: Reserving:
2269 	 *
2270 	 * From above:
2271 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2272 	 *     being created.
2273 	 *
2274 	 * Only one persistent reservation is allowed at a time per logical unit
2275 	 * and that persistent reservation has a scope of LU_SCOPE.
2276 	 */
2277 	if (scope != PR_SCOPE_LU_SCOPE) {
2278 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2279 		ret = TCM_INVALID_PARAMETER_LIST;
2280 		goto out_put_pr_reg;
2281 	}
2282 	/*
2283 	 * See if we have an existing PR reservation holder pointer at
2284 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2285 	 * *pr_res_holder.
2286 	 */
2287 	spin_lock(&dev->dev_reservation_lock);
2288 	pr_res_holder = dev->dev_pr_res_holder;
2289 	if (pr_res_holder) {
2290 		int pr_res_type = pr_res_holder->pr_res_type;
2291 		/*
2292 		 * From spc4r17 Section 5.7.9: Reserving:
2293 		 *
2294 		 * If the device server receives a PERSISTENT RESERVE OUT
2295 		 * command from an I_T nexus other than a persistent reservation
2296 		 * holder (see 5.7.10) that attempts to create a persistent
2297 		 * reservation when a persistent reservation already exists for
2298 		 * the logical unit, then the command shall be completed with
2299 		 * RESERVATION CONFLICT status.
2300 		 */
2301 		if ((pr_res_holder != pr_reg) &&
2302 		    (pr_res_type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2303 		    (pr_res_type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2304 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2305 			pr_err("SPC-3 PR: Attempted RESERVE from"
2306 				" [%s]: %s while reservation already held by"
2307 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2308 				cmd->se_tfo->get_fabric_name(),
2309 				se_sess->se_node_acl->initiatorname,
2310 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2311 				pr_res_holder->pr_reg_nacl->initiatorname);
2312 
2313 			spin_unlock(&dev->dev_reservation_lock);
2314 			ret = TCM_RESERVATION_CONFLICT;
2315 			goto out_put_pr_reg;
2316 		}
2317 		/*
2318 		 * From spc4r17 Section 5.7.9: Reserving:
2319 		 *
2320 		 * If a persistent reservation holder attempts to modify the
2321 		 * type or scope of an existing persistent reservation, the
2322 		 * command shall be completed with RESERVATION CONFLICT status.
2323 		 */
2324 		if ((pr_res_holder->pr_res_type != type) ||
2325 		    (pr_res_holder->pr_res_scope != scope)) {
2326 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2327 			pr_err("SPC-3 PR: Attempted RESERVE from"
2328 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2329 				" while reservation already held by [%s]: %s,"
2330 				" returning RESERVATION_CONFLICT\n",
2331 				cmd->se_tfo->get_fabric_name(),
2332 				se_sess->se_node_acl->initiatorname,
2333 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2334 				pr_res_holder->pr_reg_nacl->initiatorname);
2335 
2336 			spin_unlock(&dev->dev_reservation_lock);
2337 			ret = TCM_RESERVATION_CONFLICT;
2338 			goto out_put_pr_reg;
2339 		}
2340 		/*
2341 		 * From spc4r17 Section 5.7.9: Reserving:
2342 		 *
2343 		 * If the device server receives a PERSISTENT RESERVE OUT
2344 		 * command with RESERVE service action where the TYPE field and
2345 		 * the SCOPE field contain the same values as the existing type
2346 		 * and scope from a persistent reservation holder, it shall not
2347 		 * make any change to the existing persistent reservation and
2348 		 * shall completethe command with GOOD status.
2349 		 */
2350 		spin_unlock(&dev->dev_reservation_lock);
2351 		ret = 0;
2352 		goto out_put_pr_reg;
2353 	}
2354 	/*
2355 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2356 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2357 	 */
2358 	pr_reg->pr_res_scope = scope;
2359 	pr_reg->pr_res_type = type;
2360 	pr_reg->pr_res_holder = 1;
2361 	dev->dev_pr_res_holder = pr_reg;
2362 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2363 
2364 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2365 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2366 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2367 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2368 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2369 			cmd->se_tfo->get_fabric_name(),
2370 			se_sess->se_node_acl->initiatorname,
2371 			i_buf);
2372 	spin_unlock(&dev->dev_reservation_lock);
2373 
2374 	if (pr_tmpl->pr_aptpl_active)
2375 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2376 
2377 	ret = 0;
2378 out_put_pr_reg:
2379 	core_scsi3_put_pr_reg(pr_reg);
2380 	return ret;
2381 }
2382 
2383 static sense_reason_t
2384 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2385 		u64 res_key)
2386 {
2387 	switch (type) {
2388 	case PR_TYPE_WRITE_EXCLUSIVE:
2389 	case PR_TYPE_EXCLUSIVE_ACCESS:
2390 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2391 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2392 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2393 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2394 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2395 	default:
2396 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2397 			" 0x%02x\n", type);
2398 		return TCM_INVALID_CDB_FIELD;
2399 	}
2400 }
2401 
2402 /*
2403  * Called with struct se_device->dev_reservation_lock held.
2404  */
2405 static void __core_scsi3_complete_pro_release(
2406 	struct se_device *dev,
2407 	struct se_node_acl *se_nacl,
2408 	struct t10_pr_registration *pr_reg,
2409 	int explicit,
2410 	int unreg)
2411 {
2412 	struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2413 	char i_buf[PR_REG_ISID_ID_LEN];
2414 	int pr_res_type = 0, pr_res_scope = 0;
2415 
2416 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2417 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2418 	/*
2419 	 * Go ahead and release the current PR reservation holder.
2420 	 * If an All Registrants reservation is currently active and
2421 	 * a unregister operation is requested, replace the current
2422 	 * dev_pr_res_holder with another active registration.
2423 	 */
2424 	if (dev->dev_pr_res_holder) {
2425 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2426 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2427 		dev->dev_pr_res_holder->pr_res_type = 0;
2428 		dev->dev_pr_res_holder->pr_res_scope = 0;
2429 		dev->dev_pr_res_holder->pr_res_holder = 0;
2430 		dev->dev_pr_res_holder = NULL;
2431 	}
2432 	if (!unreg)
2433 		goto out;
2434 
2435 	spin_lock(&dev->t10_pr.registration_lock);
2436 	list_del_init(&pr_reg->pr_reg_list);
2437 	/*
2438 	 * If the I_T nexus is a reservation holder, the persistent reservation
2439 	 * is of an all registrants type, and the I_T nexus is the last remaining
2440 	 * registered I_T nexus, then the device server shall also release the
2441 	 * persistent reservation.
2442 	 */
2443 	if (!list_empty(&dev->t10_pr.registration_list) &&
2444 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2445 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2446 		dev->dev_pr_res_holder =
2447 			list_entry(dev->t10_pr.registration_list.next,
2448 				   struct t10_pr_registration, pr_reg_list);
2449 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2450 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2451 		dev->dev_pr_res_holder->pr_res_holder = 1;
2452 	}
2453 	spin_unlock(&dev->t10_pr.registration_lock);
2454 out:
2455 	if (!dev->dev_pr_res_holder) {
2456 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2457 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2458 			tfo->get_fabric_name(), (explicit) ? "explicit" :
2459 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2460 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2461 	}
2462 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2463 		tfo->get_fabric_name(), se_nacl->initiatorname,
2464 		i_buf);
2465 	/*
2466 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2467 	 */
2468 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2469 }
2470 
2471 static sense_reason_t
2472 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2473 		u64 res_key)
2474 {
2475 	struct se_device *dev = cmd->se_dev;
2476 	struct se_session *se_sess = cmd->se_sess;
2477 	struct se_lun *se_lun = cmd->se_lun;
2478 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2479 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2480 	int all_reg = 0;
2481 	sense_reason_t ret = 0;
2482 
2483 	if (!se_sess || !se_lun) {
2484 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2485 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2486 	}
2487 	/*
2488 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2489 	 */
2490 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2491 	if (!pr_reg) {
2492 		pr_err("SPC-3 PR: Unable to locate"
2493 			" PR_REGISTERED *pr_reg for RELEASE\n");
2494 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2495 	}
2496 	/*
2497 	 * From spc4r17 Section 5.7.11.2 Releasing:
2498 	 *
2499 	 * If there is no persistent reservation or in response to a persistent
2500 	 * reservation release request from a registered I_T nexus that is not a
2501 	 * persistent reservation holder (see 5.7.10), the device server shall
2502 	 * do the following:
2503 	 *
2504 	 *     a) Not release the persistent reservation, if any;
2505 	 *     b) Not remove any registrations; and
2506 	 *     c) Complete the command with GOOD status.
2507 	 */
2508 	spin_lock(&dev->dev_reservation_lock);
2509 	pr_res_holder = dev->dev_pr_res_holder;
2510 	if (!pr_res_holder) {
2511 		/*
2512 		 * No persistent reservation, return GOOD status.
2513 		 */
2514 		spin_unlock(&dev->dev_reservation_lock);
2515 		goto out_put_pr_reg;
2516 	}
2517 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2518 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
2519 		all_reg = 1;
2520 
2521 	if ((all_reg == 0) && (pr_res_holder != pr_reg)) {
2522 		/*
2523 		 * Non 'All Registrants' PR Type cases..
2524 		 * Release request from a registered I_T nexus that is not a
2525 		 * persistent reservation holder. return GOOD status.
2526 		 */
2527 		spin_unlock(&dev->dev_reservation_lock);
2528 		goto out_put_pr_reg;
2529 	}
2530 
2531 	/*
2532 	 * From spc4r17 Section 5.7.11.2 Releasing:
2533 	 *
2534 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2535 	 * release a persistent reservation.
2536 	 *
2537 	 * An application client releases the persistent reservation by issuing
2538 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2539 	 * an I_T nexus that is a persistent reservation holder with the
2540 	 * following parameters:
2541 	 *
2542 	 *     a) RESERVATION KEY field set to the value of the reservation key
2543 	 *	  that is registered with the logical unit for the I_T nexus;
2544 	 */
2545 	if (res_key != pr_reg->pr_res_key) {
2546 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2547 			" does not match existing SA REGISTER res_key:"
2548 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2549 		spin_unlock(&dev->dev_reservation_lock);
2550 		ret = TCM_RESERVATION_CONFLICT;
2551 		goto out_put_pr_reg;
2552 	}
2553 	/*
2554 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2555 	 *
2556 	 * b) TYPE field and SCOPE field set to match the persistent
2557 	 *    reservation being released.
2558 	 */
2559 	if ((pr_res_holder->pr_res_type != type) ||
2560 	    (pr_res_holder->pr_res_scope != scope)) {
2561 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2562 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2563 			" reservation from [%s]: %s with different TYPE "
2564 			"and/or SCOPE  while reservation already held by"
2565 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2566 			cmd->se_tfo->get_fabric_name(),
2567 			se_sess->se_node_acl->initiatorname,
2568 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2569 			pr_res_holder->pr_reg_nacl->initiatorname);
2570 
2571 		spin_unlock(&dev->dev_reservation_lock);
2572 		ret = TCM_RESERVATION_CONFLICT;
2573 		goto out_put_pr_reg;
2574 	}
2575 	/*
2576 	 * In response to a persistent reservation release request from the
2577 	 * persistent reservation holder the device server shall perform a
2578 	 * release by doing the following as an uninterrupted series of actions:
2579 	 * a) Release the persistent reservation;
2580 	 * b) Not remove any registration(s);
2581 	 * c) If the released persistent reservation is a registrants only type
2582 	 * or all registrants type persistent reservation,
2583 	 *    the device server shall establish a unit attention condition for
2584 	 *    the initiator port associated with every regis-
2585 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2586 	 *    RESERVE OUT command with RELEASE service action was received,
2587 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2588 	 * d) If the persistent reservation is of any other type, the device
2589 	 *    server shall not establish a unit attention condition.
2590 	 */
2591 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2592 					  pr_reg, 1, 0);
2593 
2594 	spin_unlock(&dev->dev_reservation_lock);
2595 
2596 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2597 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2598 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2599 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2600 		/*
2601 		 * If no UNIT ATTENTION conditions will be established for
2602 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2603 		 * go ahead and check for APTPL=1 update+write below
2604 		 */
2605 		goto write_aptpl;
2606 	}
2607 
2608 	spin_lock(&pr_tmpl->registration_lock);
2609 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2610 			pr_reg_list) {
2611 		/*
2612 		 * Do not establish a UNIT ATTENTION condition
2613 		 * for the calling I_T Nexus
2614 		 */
2615 		if (pr_reg_p == pr_reg)
2616 			continue;
2617 
2618 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2619 				pr_reg_p->pr_res_mapped_lun,
2620 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2621 	}
2622 	spin_unlock(&pr_tmpl->registration_lock);
2623 
2624 write_aptpl:
2625 	if (pr_tmpl->pr_aptpl_active)
2626 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2627 
2628 out_put_pr_reg:
2629 	core_scsi3_put_pr_reg(pr_reg);
2630 	return ret;
2631 }
2632 
2633 static sense_reason_t
2634 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2635 {
2636 	struct se_device *dev = cmd->se_dev;
2637 	struct se_node_acl *pr_reg_nacl;
2638 	struct se_session *se_sess = cmd->se_sess;
2639 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2640 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2641 	u32 pr_res_mapped_lun = 0;
2642 	int calling_it_nexus = 0;
2643 	/*
2644 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2645 	 */
2646 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2647 			se_sess->se_node_acl, se_sess);
2648 	if (!pr_reg_n) {
2649 		pr_err("SPC-3 PR: Unable to locate"
2650 			" PR_REGISTERED *pr_reg for CLEAR\n");
2651 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2652 	}
2653 	/*
2654 	 * From spc4r17 section 5.7.11.6, Clearing:
2655 	 *
2656 	 * Any application client may release the persistent reservation and
2657 	 * remove all registrations from a device server by issuing a
2658 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2659 	 * registered I_T nexus with the following parameter:
2660 	 *
2661 	 *	a) RESERVATION KEY field set to the value of the reservation key
2662 	 * 	   that is registered with the logical unit for the I_T nexus.
2663 	 */
2664 	if (res_key != pr_reg_n->pr_res_key) {
2665 		pr_err("SPC-3 PR REGISTER: Received"
2666 			" res_key: 0x%016Lx does not match"
2667 			" existing SA REGISTER res_key:"
2668 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2669 		core_scsi3_put_pr_reg(pr_reg_n);
2670 		return TCM_RESERVATION_CONFLICT;
2671 	}
2672 	/*
2673 	 * a) Release the persistent reservation, if any;
2674 	 */
2675 	spin_lock(&dev->dev_reservation_lock);
2676 	pr_res_holder = dev->dev_pr_res_holder;
2677 	if (pr_res_holder) {
2678 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2679 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2680 						  pr_res_holder, 0, 0);
2681 	}
2682 	spin_unlock(&dev->dev_reservation_lock);
2683 	/*
2684 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2685 	 */
2686 	spin_lock(&pr_tmpl->registration_lock);
2687 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2688 			&pr_tmpl->registration_list, pr_reg_list) {
2689 
2690 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2691 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2692 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2693 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2694 					calling_it_nexus);
2695 		/*
2696 		 * e) Establish a unit attention condition for the initiator
2697 		 *    port associated with every registered I_T nexus other
2698 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2699 		 *    command with CLEAR service action was received, with the
2700 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2701 		 */
2702 		if (!calling_it_nexus)
2703 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2704 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2705 	}
2706 	spin_unlock(&pr_tmpl->registration_lock);
2707 
2708 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2709 		cmd->se_tfo->get_fabric_name());
2710 
2711 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2712 
2713 	core_scsi3_pr_generation(dev);
2714 	return 0;
2715 }
2716 
2717 /*
2718  * Called with struct se_device->dev_reservation_lock held.
2719  */
2720 static void __core_scsi3_complete_pro_preempt(
2721 	struct se_device *dev,
2722 	struct t10_pr_registration *pr_reg,
2723 	struct list_head *preempt_and_abort_list,
2724 	int type,
2725 	int scope,
2726 	enum preempt_type preempt_type)
2727 {
2728 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2729 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2730 	char i_buf[PR_REG_ISID_ID_LEN];
2731 
2732 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2733 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2734 	/*
2735 	 * Do an implicit RELEASE of the existing reservation.
2736 	 */
2737 	if (dev->dev_pr_res_holder)
2738 		__core_scsi3_complete_pro_release(dev, nacl,
2739 						  dev->dev_pr_res_holder, 0, 0);
2740 
2741 	dev->dev_pr_res_holder = pr_reg;
2742 	pr_reg->pr_res_holder = 1;
2743 	pr_reg->pr_res_type = type;
2744 	pr_reg->pr_res_scope = scope;
2745 
2746 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2747 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2748 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2749 		core_scsi3_pr_dump_type(type),
2750 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2751 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2752 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2753 		nacl->initiatorname, i_buf);
2754 	/*
2755 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2756 	 * struct t10_pr_registration to the list that will be compared
2757 	 * against received CDBs..
2758 	 */
2759 	if (preempt_and_abort_list)
2760 		list_add_tail(&pr_reg->pr_reg_abort_list,
2761 				preempt_and_abort_list);
2762 }
2763 
2764 static void core_scsi3_release_preempt_and_abort(
2765 	struct list_head *preempt_and_abort_list,
2766 	struct t10_pr_registration *pr_reg_holder)
2767 {
2768 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2769 
2770 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2771 				pr_reg_abort_list) {
2772 
2773 		list_del(&pr_reg->pr_reg_abort_list);
2774 		if (pr_reg_holder == pr_reg)
2775 			continue;
2776 		if (pr_reg->pr_res_holder) {
2777 			pr_warn("pr_reg->pr_res_holder still set\n");
2778 			continue;
2779 		}
2780 
2781 		pr_reg->pr_reg_deve = NULL;
2782 		pr_reg->pr_reg_nacl = NULL;
2783 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2784 	}
2785 }
2786 
2787 static sense_reason_t
2788 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2789 		u64 sa_res_key, enum preempt_type preempt_type)
2790 {
2791 	struct se_device *dev = cmd->se_dev;
2792 	struct se_node_acl *pr_reg_nacl;
2793 	struct se_session *se_sess = cmd->se_sess;
2794 	LIST_HEAD(preempt_and_abort_list);
2795 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2796 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2797 	u32 pr_res_mapped_lun = 0;
2798 	int all_reg = 0, calling_it_nexus = 0;
2799 	bool sa_res_key_unmatched = sa_res_key != 0;
2800 	int prh_type = 0, prh_scope = 0;
2801 
2802 	if (!se_sess)
2803 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2804 
2805 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2806 				se_sess);
2807 	if (!pr_reg_n) {
2808 		pr_err("SPC-3 PR: Unable to locate"
2809 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2810 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2811 		return TCM_RESERVATION_CONFLICT;
2812 	}
2813 	if (pr_reg_n->pr_res_key != res_key) {
2814 		core_scsi3_put_pr_reg(pr_reg_n);
2815 		return TCM_RESERVATION_CONFLICT;
2816 	}
2817 	if (scope != PR_SCOPE_LU_SCOPE) {
2818 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2819 		core_scsi3_put_pr_reg(pr_reg_n);
2820 		return TCM_INVALID_PARAMETER_LIST;
2821 	}
2822 
2823 	spin_lock(&dev->dev_reservation_lock);
2824 	pr_res_holder = dev->dev_pr_res_holder;
2825 	if (pr_res_holder &&
2826 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2827 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2828 		all_reg = 1;
2829 
2830 	if (!all_reg && !sa_res_key) {
2831 		spin_unlock(&dev->dev_reservation_lock);
2832 		core_scsi3_put_pr_reg(pr_reg_n);
2833 		return TCM_INVALID_PARAMETER_LIST;
2834 	}
2835 	/*
2836 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2837 	 *
2838 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2839 	 * persistent reservation holder or there is no persistent reservation
2840 	 * holder (i.e., there is no persistent reservation), then the device
2841 	 * server shall perform a preempt by doing the following in an
2842 	 * uninterrupted series of actions. (See below..)
2843 	 */
2844 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2845 		/*
2846 		 * No existing or SA Reservation Key matching reservations..
2847 		 *
2848 		 * PROUT SA PREEMPT with All Registrant type reservations are
2849 		 * allowed to be processed without a matching SA Reservation Key
2850 		 */
2851 		spin_lock(&pr_tmpl->registration_lock);
2852 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2853 				&pr_tmpl->registration_list, pr_reg_list) {
2854 			/*
2855 			 * Removing of registrations in non all registrants
2856 			 * type reservations without a matching SA reservation
2857 			 * key.
2858 			 *
2859 			 * a) Remove the registrations for all I_T nexuses
2860 			 *    specified by the SERVICE ACTION RESERVATION KEY
2861 			 *    field;
2862 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2863 			 * c) Process tasks as defined in 5.7.1; and
2864 			 * d) Establish a unit attention condition for the
2865 			 *    initiator port associated with every I_T nexus
2866 			 *    that lost its registration other than the I_T
2867 			 *    nexus on which the PERSISTENT RESERVE OUT command
2868 			 *    was received, with the additional sense code set
2869 			 *    to REGISTRATIONS PREEMPTED.
2870 			 */
2871 			if (!all_reg) {
2872 				if (pr_reg->pr_res_key != sa_res_key)
2873 					continue;
2874 				sa_res_key_unmatched = false;
2875 
2876 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2877 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2878 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2879 				__core_scsi3_free_registration(dev, pr_reg,
2880 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2881 						NULL, calling_it_nexus);
2882 			} else {
2883 				/*
2884 				 * Case for any existing all registrants type
2885 				 * reservation, follow logic in spc4r17 section
2886 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2887 				 *
2888 				 * For a ZERO SA Reservation key, release
2889 				 * all other registrations and do an implicit
2890 				 * release of active persistent reservation.
2891 				 *
2892 				 * For a non-ZERO SA Reservation key, only
2893 				 * release the matching reservation key from
2894 				 * registrations.
2895 				 */
2896 				if ((sa_res_key) &&
2897 				     (pr_reg->pr_res_key != sa_res_key))
2898 					continue;
2899 				sa_res_key_unmatched = false;
2900 
2901 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2902 				if (calling_it_nexus)
2903 					continue;
2904 
2905 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2906 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2907 				__core_scsi3_free_registration(dev, pr_reg,
2908 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2909 						NULL, 0);
2910 			}
2911 			if (!calling_it_nexus)
2912 				core_scsi3_ua_allocate(pr_reg_nacl,
2913 					pr_res_mapped_lun, 0x2A,
2914 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2915 		}
2916 		spin_unlock(&pr_tmpl->registration_lock);
2917 		/*
2918 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2919 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2920 		 * RESERVATION KEY field to a value that does not match any
2921 		 * registered reservation key, then the device server shall
2922 		 * complete the command with RESERVATION CONFLICT status.
2923 		 */
2924 		if (sa_res_key_unmatched) {
2925 			spin_unlock(&dev->dev_reservation_lock);
2926 			core_scsi3_put_pr_reg(pr_reg_n);
2927 			return TCM_RESERVATION_CONFLICT;
2928 		}
2929 		/*
2930 		 * For an existing all registrants type reservation
2931 		 * with a zero SA rservation key, preempt the existing
2932 		 * reservation with the new PR type and scope.
2933 		 */
2934 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2935 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2936 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2937 				type, scope, preempt_type);
2938 
2939 			if (preempt_type == PREEMPT_AND_ABORT)
2940 				core_scsi3_release_preempt_and_abort(
2941 					&preempt_and_abort_list, pr_reg_n);
2942 		}
2943 		spin_unlock(&dev->dev_reservation_lock);
2944 
2945 		if (pr_tmpl->pr_aptpl_active)
2946 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2947 
2948 		core_scsi3_put_pr_reg(pr_reg_n);
2949 		core_scsi3_pr_generation(cmd->se_dev);
2950 		return 0;
2951 	}
2952 	/*
2953 	 * The PREEMPTing SA reservation key matches that of the
2954 	 * existing persistent reservation, first, we check if
2955 	 * we are preempting our own reservation.
2956 	 * From spc4r17, section 5.7.11.4.3 Preempting
2957 	 * persistent reservations and registration handling
2958 	 *
2959 	 * If an all registrants persistent reservation is not
2960 	 * present, it is not an error for the persistent
2961 	 * reservation holder to preempt itself (i.e., a
2962 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
2963 	 * or a PREEMPT AND ABORT service action with the
2964 	 * SERVICE ACTION RESERVATION KEY value equal to the
2965 	 * persistent reservation holder's reservation key that
2966 	 * is received from the persistent reservation holder).
2967 	 * In that case, the device server shall establish the
2968 	 * new persistent reservation and maintain the
2969 	 * registration.
2970 	 */
2971 	prh_type = pr_res_holder->pr_res_type;
2972 	prh_scope = pr_res_holder->pr_res_scope;
2973 	/*
2974 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
2975 	 * persistent reservation holder (see 5.7.10), the device
2976 	 * server shall perform a preempt by doing the following as
2977 	 * an uninterrupted series of actions:
2978 	 *
2979 	 * a) Release the persistent reservation for the holder
2980 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
2981 	 */
2982 	if (pr_reg_n != pr_res_holder)
2983 		__core_scsi3_complete_pro_release(dev,
2984 						  pr_res_holder->pr_reg_nacl,
2985 						  dev->dev_pr_res_holder, 0, 0);
2986 	/*
2987 	 * b) Remove the registrations for all I_T nexuses identified
2988 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
2989 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
2990 	 *    OUT command. If an all registrants persistent reservation
2991 	 *    is present and the SERVICE ACTION RESERVATION KEY field
2992 	 *    is set to zero, then all registrations shall be removed
2993 	 *    except for that of the I_T nexus that is being used for
2994 	 *    the PERSISTENT RESERVE OUT command;
2995 	 */
2996 	spin_lock(&pr_tmpl->registration_lock);
2997 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2998 			&pr_tmpl->registration_list, pr_reg_list) {
2999 
3000 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3001 		if (calling_it_nexus)
3002 			continue;
3003 
3004 		if (pr_reg->pr_res_key != sa_res_key)
3005 			continue;
3006 
3007 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3008 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3009 		__core_scsi3_free_registration(dev, pr_reg,
3010 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3011 				calling_it_nexus);
3012 		/*
3013 		 * e) Establish a unit attention condition for the initiator
3014 		 *    port associated with every I_T nexus that lost its
3015 		 *    persistent reservation and/or registration, with the
3016 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3017 		 */
3018 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3019 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3020 	}
3021 	spin_unlock(&pr_tmpl->registration_lock);
3022 	/*
3023 	 * c) Establish a persistent reservation for the preempting
3024 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3025 	 */
3026 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3027 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3028 			type, scope, preempt_type);
3029 	/*
3030 	 * d) Process tasks as defined in 5.7.1;
3031 	 * e) See above..
3032 	 * f) If the type or scope has changed, then for every I_T nexus
3033 	 *    whose reservation key was not removed, except for the I_T
3034 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3035 	 *    received, the device server shall establish a unit
3036 	 *    attention condition for the initiator port associated with
3037 	 *    that I_T nexus, with the additional sense code set to
3038 	 *    RESERVATIONS RELEASED. If the type or scope have not
3039 	 *    changed, then no unit attention condition(s) shall be
3040 	 *    established for this reason.
3041 	 */
3042 	if ((prh_type != type) || (prh_scope != scope)) {
3043 		spin_lock(&pr_tmpl->registration_lock);
3044 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3045 				&pr_tmpl->registration_list, pr_reg_list) {
3046 
3047 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3048 			if (calling_it_nexus)
3049 				continue;
3050 
3051 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
3052 					pr_reg->pr_res_mapped_lun, 0x2A,
3053 					ASCQ_2AH_RESERVATIONS_RELEASED);
3054 		}
3055 		spin_unlock(&pr_tmpl->registration_lock);
3056 	}
3057 	spin_unlock(&dev->dev_reservation_lock);
3058 	/*
3059 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3060 	 * All received CDBs for the matching existing reservation and
3061 	 * registrations undergo ABORT_TASK logic.
3062 	 *
3063 	 * From there, core_scsi3_release_preempt_and_abort() will
3064 	 * release every registration in the list (which have already
3065 	 * been removed from the primary pr_reg list), except the
3066 	 * new persistent reservation holder, the calling Initiator Port.
3067 	 */
3068 	if (preempt_type == PREEMPT_AND_ABORT) {
3069 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3070 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3071 						pr_reg_n);
3072 	}
3073 
3074 	if (pr_tmpl->pr_aptpl_active)
3075 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3076 
3077 	core_scsi3_put_pr_reg(pr_reg_n);
3078 	core_scsi3_pr_generation(cmd->se_dev);
3079 	return 0;
3080 }
3081 
3082 static sense_reason_t
3083 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3084 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3085 {
3086 	switch (type) {
3087 	case PR_TYPE_WRITE_EXCLUSIVE:
3088 	case PR_TYPE_EXCLUSIVE_ACCESS:
3089 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3090 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3091 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3092 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3093 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3094 					      sa_res_key, preempt_type);
3095 	default:
3096 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3097 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3098 		return TCM_INVALID_CDB_FIELD;
3099 	}
3100 }
3101 
3102 
3103 static sense_reason_t
3104 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3105 		u64 sa_res_key, int aptpl, int unreg)
3106 {
3107 	struct se_session *se_sess = cmd->se_sess;
3108 	struct se_device *dev = cmd->se_dev;
3109 	struct se_dev_entry *dest_se_deve = NULL;
3110 	struct se_lun *se_lun = cmd->se_lun;
3111 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3112 	struct se_port *se_port;
3113 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3114 	struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3115 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3116 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3117 	unsigned char *buf;
3118 	unsigned char *initiator_str;
3119 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
3120 	u32 tid_len, tmp_tid_len;
3121 	int new_reg = 0, type, scope, matching_iname;
3122 	sense_reason_t ret;
3123 	unsigned short rtpi;
3124 	unsigned char proto_ident;
3125 
3126 	if (!se_sess || !se_lun) {
3127 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3128 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3129 	}
3130 
3131 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3132 	se_tpg = se_sess->se_tpg;
3133 	tf_ops = se_tpg->se_tpg_tfo;
3134 	/*
3135 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3136 	 *	Register behaviors for a REGISTER AND MOVE service action
3137 	 *
3138 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3139 	 */
3140 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3141 				se_sess);
3142 	if (!pr_reg) {
3143 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3144 			" *pr_reg for REGISTER_AND_MOVE\n");
3145 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3146 	}
3147 	/*
3148 	 * The provided reservation key much match the existing reservation key
3149 	 * provided during this initiator's I_T nexus registration.
3150 	 */
3151 	if (res_key != pr_reg->pr_res_key) {
3152 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3153 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3154 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3155 		ret = TCM_RESERVATION_CONFLICT;
3156 		goto out_put_pr_reg;
3157 	}
3158 	/*
3159 	 * The service active reservation key needs to be non zero
3160 	 */
3161 	if (!sa_res_key) {
3162 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3163 			" sa_res_key\n");
3164 		ret = TCM_INVALID_PARAMETER_LIST;
3165 		goto out_put_pr_reg;
3166 	}
3167 
3168 	/*
3169 	 * Determine the Relative Target Port Identifier where the reservation
3170 	 * will be moved to for the TransportID containing SCSI initiator WWN
3171 	 * information.
3172 	 */
3173 	buf = transport_kmap_data_sg(cmd);
3174 	if (!buf) {
3175 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3176 		goto out_put_pr_reg;
3177 	}
3178 
3179 	rtpi = (buf[18] & 0xff) << 8;
3180 	rtpi |= buf[19] & 0xff;
3181 	tid_len = (buf[20] & 0xff) << 24;
3182 	tid_len |= (buf[21] & 0xff) << 16;
3183 	tid_len |= (buf[22] & 0xff) << 8;
3184 	tid_len |= buf[23] & 0xff;
3185 	transport_kunmap_data_sg(cmd);
3186 	buf = NULL;
3187 
3188 	if ((tid_len + 24) != cmd->data_length) {
3189 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3190 			" does not equal CDB data_length: %u\n", tid_len,
3191 			cmd->data_length);
3192 		ret = TCM_INVALID_PARAMETER_LIST;
3193 		goto out_put_pr_reg;
3194 	}
3195 
3196 	spin_lock(&dev->se_port_lock);
3197 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3198 		if (se_port->sep_rtpi != rtpi)
3199 			continue;
3200 		dest_se_tpg = se_port->sep_tpg;
3201 		if (!dest_se_tpg)
3202 			continue;
3203 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3204 		if (!dest_tf_ops)
3205 			continue;
3206 
3207 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3208 		spin_unlock(&dev->se_port_lock);
3209 
3210 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3211 			pr_err("core_scsi3_tpg_depend_item() failed"
3212 				" for dest_se_tpg\n");
3213 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3214 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3215 			goto out_put_pr_reg;
3216 		}
3217 
3218 		spin_lock(&dev->se_port_lock);
3219 		break;
3220 	}
3221 	spin_unlock(&dev->se_port_lock);
3222 
3223 	if (!dest_se_tpg || !dest_tf_ops) {
3224 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3225 			" fabric ops from Relative Target Port Identifier:"
3226 			" %hu\n", rtpi);
3227 		ret = TCM_INVALID_PARAMETER_LIST;
3228 		goto out_put_pr_reg;
3229 	}
3230 
3231 	buf = transport_kmap_data_sg(cmd);
3232 	if (!buf) {
3233 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3234 		goto out_put_pr_reg;
3235 	}
3236 	proto_ident = (buf[24] & 0x0f);
3237 
3238 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3239 			" 0x%02x\n", proto_ident);
3240 
3241 	if (proto_ident != dest_tf_ops->get_fabric_proto_ident(dest_se_tpg)) {
3242 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3243 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3244 			" from fabric: %s\n", proto_ident,
3245 			dest_tf_ops->get_fabric_proto_ident(dest_se_tpg),
3246 			dest_tf_ops->get_fabric_name());
3247 		ret = TCM_INVALID_PARAMETER_LIST;
3248 		goto out;
3249 	}
3250 	if (dest_tf_ops->tpg_parse_pr_out_transport_id == NULL) {
3251 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Fabric does not"
3252 			" containg a valid tpg_parse_pr_out_transport_id"
3253 			" function pointer\n");
3254 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3255 		goto out;
3256 	}
3257 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(dest_se_tpg,
3258 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3259 	if (!initiator_str) {
3260 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3261 			" initiator_str from Transport ID\n");
3262 		ret = TCM_INVALID_PARAMETER_LIST;
3263 		goto out;
3264 	}
3265 
3266 	transport_kunmap_data_sg(cmd);
3267 	buf = NULL;
3268 
3269 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3270 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3271 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3272 		iport_ptr : "");
3273 	/*
3274 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3275 	 * action specifies a TransportID that is the same as the initiator port
3276 	 * of the I_T nexus for the command received, then the command shall
3277 	 * be terminated with CHECK CONDITION status, with the sense key set to
3278 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3279 	 * IN PARAMETER LIST.
3280 	 */
3281 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3282 	matching_iname = (!strcmp(initiator_str,
3283 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3284 	if (!matching_iname)
3285 		goto after_iport_check;
3286 
3287 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3288 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3289 			" matches: %s on received I_T Nexus\n", initiator_str,
3290 			pr_reg_nacl->initiatorname);
3291 		ret = TCM_INVALID_PARAMETER_LIST;
3292 		goto out;
3293 	}
3294 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3295 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3296 			" matches: %s %s on received I_T Nexus\n",
3297 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3298 			pr_reg->pr_reg_isid);
3299 		ret = TCM_INVALID_PARAMETER_LIST;
3300 		goto out;
3301 	}
3302 after_iport_check:
3303 	/*
3304 	 * Locate the destination struct se_node_acl from the received Transport ID
3305 	 */
3306 	spin_lock_irq(&dest_se_tpg->acl_node_lock);
3307 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3308 				initiator_str);
3309 	if (dest_node_acl)
3310 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3311 	spin_unlock_irq(&dest_se_tpg->acl_node_lock);
3312 
3313 	if (!dest_node_acl) {
3314 		pr_err("Unable to locate %s dest_node_acl for"
3315 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3316 			initiator_str);
3317 		ret = TCM_INVALID_PARAMETER_LIST;
3318 		goto out;
3319 	}
3320 
3321 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3322 		pr_err("core_scsi3_nodeacl_depend_item() for"
3323 			" dest_node_acl\n");
3324 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3325 		dest_node_acl = NULL;
3326 		ret = TCM_INVALID_PARAMETER_LIST;
3327 		goto out;
3328 	}
3329 
3330 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3331 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3332 		dest_node_acl->initiatorname);
3333 
3334 	/*
3335 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3336 	 * PORT IDENTIFIER.
3337 	 */
3338 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3339 	if (!dest_se_deve) {
3340 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3341 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3342 		ret = TCM_INVALID_PARAMETER_LIST;
3343 		goto out;
3344 	}
3345 
3346 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3347 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3348 		atomic_dec_mb(&dest_se_deve->pr_ref_count);
3349 		dest_se_deve = NULL;
3350 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3351 		goto out;
3352 	}
3353 
3354 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3355 		" ACL for dest_se_deve->mapped_lun: %u\n",
3356 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3357 		dest_se_deve->mapped_lun);
3358 
3359 	/*
3360 	 * A persistent reservation needs to already existing in order to
3361 	 * successfully complete the REGISTER_AND_MOVE service action..
3362 	 */
3363 	spin_lock(&dev->dev_reservation_lock);
3364 	pr_res_holder = dev->dev_pr_res_holder;
3365 	if (!pr_res_holder) {
3366 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3367 			" currently held\n");
3368 		spin_unlock(&dev->dev_reservation_lock);
3369 		ret = TCM_INVALID_CDB_FIELD;
3370 		goto out;
3371 	}
3372 	/*
3373 	 * The received on I_T Nexus must be the reservation holder.
3374 	 *
3375 	 * From spc4r17 section 5.7.8  Table 50 --
3376 	 * 	Register behaviors for a REGISTER AND MOVE service action
3377 	 */
3378 	if (pr_res_holder != pr_reg) {
3379 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3380 			" Nexus is not reservation holder\n");
3381 		spin_unlock(&dev->dev_reservation_lock);
3382 		ret = TCM_RESERVATION_CONFLICT;
3383 		goto out;
3384 	}
3385 	/*
3386 	 * From spc4r17 section 5.7.8: registering and moving reservation
3387 	 *
3388 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3389 	 * action is received and the established persistent reservation is a
3390 	 * Write Exclusive - All Registrants type or Exclusive Access -
3391 	 * All Registrants type reservation, then the command shall be completed
3392 	 * with RESERVATION CONFLICT status.
3393 	 */
3394 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3395 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3396 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3397 			" reservation for type: %s\n",
3398 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3399 		spin_unlock(&dev->dev_reservation_lock);
3400 		ret = TCM_RESERVATION_CONFLICT;
3401 		goto out;
3402 	}
3403 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3404 	/*
3405 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3406 	 */
3407 	type = pr_res_holder->pr_res_type;
3408 	scope = pr_res_holder->pr_res_type;
3409 	/*
3410 	 * c) Associate the reservation key specified in the SERVICE ACTION
3411 	 *    RESERVATION KEY field with the I_T nexus specified as the
3412 	 *    destination of the register and move, where:
3413 	 *    A) The I_T nexus is specified by the TransportID and the
3414 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3415 	 *    B) Regardless of the TransportID format used, the association for
3416 	 *       the initiator port is based on either the initiator port name
3417 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3418 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3419 	 *       transport protocols where port names are not required;
3420 	 * d) Register the reservation key specified in the SERVICE ACTION
3421 	 *    RESERVATION KEY field;
3422 	 * e) Retain the reservation key specified in the SERVICE ACTION
3423 	 *    RESERVATION KEY field and associated information;
3424 	 *
3425 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3426 	 * register an I_T nexus that is already registered with the same
3427 	 * reservation key or a different reservation key.
3428 	 */
3429 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3430 					iport_ptr);
3431 	if (!dest_pr_reg) {
3432 		if (core_scsi3_alloc_registration(cmd->se_dev,
3433 				dest_node_acl, dest_se_deve, iport_ptr,
3434 				sa_res_key, 0, aptpl, 2, 1)) {
3435 			spin_unlock(&dev->dev_reservation_lock);
3436 			ret = TCM_INVALID_PARAMETER_LIST;
3437 			goto out;
3438 		}
3439 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3440 						iport_ptr);
3441 		new_reg = 1;
3442 	}
3443 	/*
3444 	 * f) Release the persistent reservation for the persistent reservation
3445 	 *    holder (i.e., the I_T nexus on which the
3446 	 */
3447 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3448 					  dev->dev_pr_res_holder, 0, 0);
3449 	/*
3450 	 * g) Move the persistent reservation to the specified I_T nexus using
3451 	 *    the same scope and type as the persistent reservation released in
3452 	 *    item f); and
3453 	 */
3454 	dev->dev_pr_res_holder = dest_pr_reg;
3455 	dest_pr_reg->pr_res_holder = 1;
3456 	dest_pr_reg->pr_res_type = type;
3457 	pr_reg->pr_res_scope = scope;
3458 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3459 	/*
3460 	 * Increment PRGeneration for existing registrations..
3461 	 */
3462 	if (!new_reg)
3463 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3464 	spin_unlock(&dev->dev_reservation_lock);
3465 
3466 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3467 		" created new reservation holder TYPE: %s on object RTPI:"
3468 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3469 		core_scsi3_pr_dump_type(type), rtpi,
3470 		dest_pr_reg->pr_res_generation);
3471 	pr_debug("SPC-3 PR Successfully moved reservation from"
3472 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3473 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3474 		i_buf, dest_tf_ops->get_fabric_name(),
3475 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3476 		iport_ptr : "");
3477 	/*
3478 	 * It is now safe to release configfs group dependencies for destination
3479 	 * of Transport ID Initiator Device/Port Identifier
3480 	 */
3481 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3482 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3483 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3484 	/*
3485 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3486 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3487 	 */
3488 	if (unreg) {
3489 		spin_lock(&pr_tmpl->registration_lock);
3490 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3491 		spin_unlock(&pr_tmpl->registration_lock);
3492 	} else
3493 		core_scsi3_put_pr_reg(pr_reg);
3494 
3495 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3496 
3497 	transport_kunmap_data_sg(cmd);
3498 
3499 	core_scsi3_put_pr_reg(dest_pr_reg);
3500 	return 0;
3501 out:
3502 	if (buf)
3503 		transport_kunmap_data_sg(cmd);
3504 	if (dest_se_deve)
3505 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3506 	if (dest_node_acl)
3507 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3508 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3509 
3510 out_put_pr_reg:
3511 	core_scsi3_put_pr_reg(pr_reg);
3512 	return ret;
3513 }
3514 
3515 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3516 {
3517 	unsigned int __v1, __v2;
3518 
3519 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3520 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3521 
3522 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3523 }
3524 
3525 /*
3526  * See spc4r17 section 6.14 Table 170
3527  */
3528 sense_reason_t
3529 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3530 {
3531 	struct se_device *dev = cmd->se_dev;
3532 	unsigned char *cdb = &cmd->t_task_cdb[0];
3533 	unsigned char *buf;
3534 	u64 res_key, sa_res_key;
3535 	int sa, scope, type, aptpl;
3536 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3537 	sense_reason_t ret;
3538 
3539 	/*
3540 	 * Following spc2r20 5.5.1 Reservations overview:
3541 	 *
3542 	 * If a logical unit has been reserved by any RESERVE command and is
3543 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3544 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3545 	 * initiator or service action and shall terminate with a RESERVATION
3546 	 * CONFLICT status.
3547 	 */
3548 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3549 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3550 			" SPC-2 reservation is held, returning"
3551 			" RESERVATION_CONFLICT\n");
3552 		return TCM_RESERVATION_CONFLICT;
3553 	}
3554 
3555 	/*
3556 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3557 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3558 	 */
3559 	if (!cmd->se_sess)
3560 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3561 
3562 	if (cmd->data_length < 24) {
3563 		pr_warn("SPC-PR: Received PR OUT parameter list"
3564 			" length too small: %u\n", cmd->data_length);
3565 		return TCM_INVALID_PARAMETER_LIST;
3566 	}
3567 
3568 	/*
3569 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3570 	 */
3571 	sa = (cdb[1] & 0x1f);
3572 	scope = (cdb[2] & 0xf0);
3573 	type = (cdb[2] & 0x0f);
3574 
3575 	buf = transport_kmap_data_sg(cmd);
3576 	if (!buf)
3577 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3578 
3579 	/*
3580 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3581 	 */
3582 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3583 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3584 	/*
3585 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3586 	 * SCSI TransportIDs.
3587 	 */
3588 	if (sa != PRO_REGISTER_AND_MOVE) {
3589 		spec_i_pt = (buf[20] & 0x08);
3590 		all_tg_pt = (buf[20] & 0x04);
3591 		aptpl = (buf[20] & 0x01);
3592 	} else {
3593 		aptpl = (buf[17] & 0x01);
3594 		unreg = (buf[17] & 0x02);
3595 	}
3596 	/*
3597 	 * If the backend device has been configured to force APTPL metadata
3598 	 * write-out, go ahead and propigate aptpl=1 down now.
3599 	 */
3600 	if (dev->dev_attrib.force_pr_aptpl)
3601 		aptpl = 1;
3602 
3603 	transport_kunmap_data_sg(cmd);
3604 	buf = NULL;
3605 
3606 	/*
3607 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3608 	 */
3609 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER))
3610 		return TCM_INVALID_PARAMETER_LIST;
3611 
3612 	/*
3613 	 * From spc4r17 section 6.14:
3614 	 *
3615 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3616 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3617 	 * the command shall be terminated with CHECK CONDITION status, with
3618 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3619 	 * code set to PARAMETER LIST LENGTH ERROR.
3620 	 */
3621 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3622 	    (cmd->data_length != 24)) {
3623 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3624 			" list length: %u\n", cmd->data_length);
3625 		return TCM_INVALID_PARAMETER_LIST;
3626 	}
3627 
3628 	/*
3629 	 * (core_scsi3_emulate_pro_* function parameters
3630 	 * are defined by spc4r17 Table 174:
3631 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3632 	 */
3633 	switch (sa) {
3634 	case PRO_REGISTER:
3635 		ret = core_scsi3_emulate_pro_register(cmd,
3636 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3637 		break;
3638 	case PRO_RESERVE:
3639 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3640 		break;
3641 	case PRO_RELEASE:
3642 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3643 		break;
3644 	case PRO_CLEAR:
3645 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3646 		break;
3647 	case PRO_PREEMPT:
3648 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3649 					res_key, sa_res_key, PREEMPT);
3650 		break;
3651 	case PRO_PREEMPT_AND_ABORT:
3652 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3653 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3654 		break;
3655 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3656 		ret = core_scsi3_emulate_pro_register(cmd,
3657 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3658 		break;
3659 	case PRO_REGISTER_AND_MOVE:
3660 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3661 				sa_res_key, aptpl, unreg);
3662 		break;
3663 	default:
3664 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3665 			" action: 0x%02x\n", cdb[1] & 0x1f);
3666 		return TCM_INVALID_CDB_FIELD;
3667 	}
3668 
3669 	if (!ret)
3670 		target_complete_cmd(cmd, GOOD);
3671 	return ret;
3672 }
3673 
3674 /*
3675  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3676  *
3677  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3678  */
3679 static sense_reason_t
3680 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3681 {
3682 	struct se_device *dev = cmd->se_dev;
3683 	struct t10_pr_registration *pr_reg;
3684 	unsigned char *buf;
3685 	u32 add_len = 0, off = 8;
3686 
3687 	if (cmd->data_length < 8) {
3688 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3689 			" too small\n", cmd->data_length);
3690 		return TCM_INVALID_CDB_FIELD;
3691 	}
3692 
3693 	buf = transport_kmap_data_sg(cmd);
3694 	if (!buf)
3695 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3696 
3697 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3698 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3699 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3700 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3701 
3702 	spin_lock(&dev->t10_pr.registration_lock);
3703 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3704 			pr_reg_list) {
3705 		/*
3706 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3707 		 * next reservation key list descriptor.
3708 		 */
3709 		if ((add_len + 8) > (cmd->data_length - 8))
3710 			break;
3711 
3712 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3713 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3714 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3715 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3716 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3717 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3718 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3719 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3720 
3721 		add_len += 8;
3722 	}
3723 	spin_unlock(&dev->t10_pr.registration_lock);
3724 
3725 	buf[4] = ((add_len >> 24) & 0xff);
3726 	buf[5] = ((add_len >> 16) & 0xff);
3727 	buf[6] = ((add_len >> 8) & 0xff);
3728 	buf[7] = (add_len & 0xff);
3729 
3730 	transport_kunmap_data_sg(cmd);
3731 
3732 	return 0;
3733 }
3734 
3735 /*
3736  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3737  *
3738  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3739  */
3740 static sense_reason_t
3741 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3742 {
3743 	struct se_device *dev = cmd->se_dev;
3744 	struct t10_pr_registration *pr_reg;
3745 	unsigned char *buf;
3746 	u64 pr_res_key;
3747 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3748 
3749 	if (cmd->data_length < 8) {
3750 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3751 			" too small\n", cmd->data_length);
3752 		return TCM_INVALID_CDB_FIELD;
3753 	}
3754 
3755 	buf = transport_kmap_data_sg(cmd);
3756 	if (!buf)
3757 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3758 
3759 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3760 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3761 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3762 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3763 
3764 	spin_lock(&dev->dev_reservation_lock);
3765 	pr_reg = dev->dev_pr_res_holder;
3766 	if (pr_reg) {
3767 		/*
3768 		 * Set the hardcoded Additional Length
3769 		 */
3770 		buf[4] = ((add_len >> 24) & 0xff);
3771 		buf[5] = ((add_len >> 16) & 0xff);
3772 		buf[6] = ((add_len >> 8) & 0xff);
3773 		buf[7] = (add_len & 0xff);
3774 
3775 		if (cmd->data_length < 22)
3776 			goto err;
3777 
3778 		/*
3779 		 * Set the Reservation key.
3780 		 *
3781 		 * From spc4r17, section 5.7.10:
3782 		 * A persistent reservation holder has its reservation key
3783 		 * returned in the parameter data from a PERSISTENT
3784 		 * RESERVE IN command with READ RESERVATION service action as
3785 		 * follows:
3786 		 * a) For a persistent reservation of the type Write Exclusive
3787 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3788 		 *      the reservation key shall be set to zero; or
3789 		 * b) For all other persistent reservation types, the
3790 		 *    reservation key shall be set to the registered
3791 		 *    reservation key for the I_T nexus that holds the
3792 		 *    persistent reservation.
3793 		 */
3794 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3795 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3796 			pr_res_key = 0;
3797 		else
3798 			pr_res_key = pr_reg->pr_res_key;
3799 
3800 		buf[8] = ((pr_res_key >> 56) & 0xff);
3801 		buf[9] = ((pr_res_key >> 48) & 0xff);
3802 		buf[10] = ((pr_res_key >> 40) & 0xff);
3803 		buf[11] = ((pr_res_key >> 32) & 0xff);
3804 		buf[12] = ((pr_res_key >> 24) & 0xff);
3805 		buf[13] = ((pr_res_key >> 16) & 0xff);
3806 		buf[14] = ((pr_res_key >> 8) & 0xff);
3807 		buf[15] = (pr_res_key & 0xff);
3808 		/*
3809 		 * Set the SCOPE and TYPE
3810 		 */
3811 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3812 			  (pr_reg->pr_res_type & 0x0f);
3813 	}
3814 
3815 err:
3816 	spin_unlock(&dev->dev_reservation_lock);
3817 	transport_kunmap_data_sg(cmd);
3818 
3819 	return 0;
3820 }
3821 
3822 /*
3823  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3824  *
3825  * See spc4r17 section 6.13.4 Table 165
3826  */
3827 static sense_reason_t
3828 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3829 {
3830 	struct se_device *dev = cmd->se_dev;
3831 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3832 	unsigned char *buf;
3833 	u16 add_len = 8; /* Hardcoded to 8. */
3834 
3835 	if (cmd->data_length < 6) {
3836 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3837 			" %u too small\n", cmd->data_length);
3838 		return TCM_INVALID_CDB_FIELD;
3839 	}
3840 
3841 	buf = transport_kmap_data_sg(cmd);
3842 	if (!buf)
3843 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3844 
3845 	buf[0] = ((add_len >> 8) & 0xff);
3846 	buf[1] = (add_len & 0xff);
3847 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3848 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3849 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3850 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3851 	/*
3852 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3853 	 * set the TMV: Task Mask Valid bit.
3854 	 */
3855 	buf[3] |= 0x80;
3856 	/*
3857 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3858 	 */
3859 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3860 	/*
3861 	 * PTPL_A: Persistence across Target Power Loss Active bit
3862 	 */
3863 	if (pr_tmpl->pr_aptpl_active)
3864 		buf[3] |= 0x01;
3865 	/*
3866 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3867 	 */
3868 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3869 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3870 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3871 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3872 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3873 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3874 
3875 	transport_kunmap_data_sg(cmd);
3876 
3877 	return 0;
3878 }
3879 
3880 /*
3881  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3882  *
3883  * See spc4r17 section 6.13.5 Table 168 and 169
3884  */
3885 static sense_reason_t
3886 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3887 {
3888 	struct se_device *dev = cmd->se_dev;
3889 	struct se_node_acl *se_nacl;
3890 	struct se_portal_group *se_tpg;
3891 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3892 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3893 	unsigned char *buf;
3894 	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
3895 	u32 off = 8; /* off into first Full Status descriptor */
3896 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3897 	bool all_reg = false;
3898 
3899 	if (cmd->data_length < 8) {
3900 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3901 			" too small\n", cmd->data_length);
3902 		return TCM_INVALID_CDB_FIELD;
3903 	}
3904 
3905 	buf = transport_kmap_data_sg(cmd);
3906 	if (!buf)
3907 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3908 
3909 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3910 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3911 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3912 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3913 
3914 	spin_lock(&dev->dev_reservation_lock);
3915 	if (dev->dev_pr_res_holder) {
3916 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3917 
3918 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3919 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3920 			all_reg = true;
3921 			pr_res_type = pr_holder->pr_res_type;
3922 			pr_res_scope = pr_holder->pr_res_scope;
3923 		}
3924 	}
3925 	spin_unlock(&dev->dev_reservation_lock);
3926 
3927 	spin_lock(&pr_tmpl->registration_lock);
3928 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3929 			&pr_tmpl->registration_list, pr_reg_list) {
3930 
3931 		se_nacl = pr_reg->pr_reg_nacl;
3932 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3933 		add_desc_len = 0;
3934 
3935 		atomic_inc_mb(&pr_reg->pr_res_holders);
3936 		spin_unlock(&pr_tmpl->registration_lock);
3937 		/*
3938 		 * Determine expected length of $FABRIC_MOD specific
3939 		 * TransportID full status descriptor..
3940 		 */
3941 		exp_desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id_len(
3942 				se_tpg, se_nacl, pr_reg, &format_code);
3943 
3944 		if ((exp_desc_len + add_len) > cmd->data_length) {
3945 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3946 				" out of buffer: %d\n", cmd->data_length);
3947 			spin_lock(&pr_tmpl->registration_lock);
3948 			atomic_dec_mb(&pr_reg->pr_res_holders);
3949 			break;
3950 		}
3951 		/*
3952 		 * Set RESERVATION KEY
3953 		 */
3954 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3955 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3956 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3957 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3958 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3959 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3960 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3961 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3962 		off += 4; /* Skip Over Reserved area */
3963 
3964 		/*
3965 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3966 		 */
3967 		if (pr_reg->pr_reg_all_tg_pt)
3968 			buf[off] = 0x02;
3969 		/*
3970 		 * The struct se_lun pointer will be present for the
3971 		 * reservation holder for PR_HOLDER bit.
3972 		 *
3973 		 * Also, if this registration is the reservation
3974 		 * holder or there is an All Registrants reservation
3975 		 * active, fill in SCOPE and TYPE in the next byte.
3976 		 */
3977 		if (pr_reg->pr_res_holder) {
3978 			buf[off++] |= 0x01;
3979 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3980 				     (pr_reg->pr_res_type & 0x0f);
3981 		} else if (all_reg) {
3982 			buf[off++] |= 0x01;
3983 			buf[off++] = (pr_res_scope & 0xf0) |
3984 				     (pr_res_type & 0x0f);
3985 		} else {
3986 			off += 2;
3987 		}
3988 
3989 		off += 4; /* Skip over reserved area */
3990 		/*
3991 		 * From spc4r17 6.3.15:
3992 		 *
3993 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
3994 		 * IDENTIFIER field contains the relative port identifier (see
3995 		 * 3.1.120) of the target port that is part of the I_T nexus
3996 		 * described by this full status descriptor. If the ALL_TG_PT
3997 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
3998 		 * IDENTIFIER field are not defined by this standard.
3999 		 */
4000 		if (!pr_reg->pr_reg_all_tg_pt) {
4001 			struct se_port *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
4002 
4003 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
4004 			buf[off++] = (port->sep_rtpi & 0xff);
4005 		} else
4006 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
4007 
4008 		/*
4009 		 * Now, have the $FABRIC_MOD fill in the protocol identifier
4010 		 */
4011 		desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id(se_tpg,
4012 				se_nacl, pr_reg, &format_code, &buf[off+4]);
4013 
4014 		spin_lock(&pr_tmpl->registration_lock);
4015 		atomic_dec_mb(&pr_reg->pr_res_holders);
4016 		/*
4017 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4018 		 */
4019 		buf[off++] = ((desc_len >> 24) & 0xff);
4020 		buf[off++] = ((desc_len >> 16) & 0xff);
4021 		buf[off++] = ((desc_len >> 8) & 0xff);
4022 		buf[off++] = (desc_len & 0xff);
4023 		/*
4024 		 * Size of full desctipor header minus TransportID
4025 		 * containing $FABRIC_MOD specific) initiator device/port
4026 		 * WWN information.
4027 		 *
4028 		 *  See spc4r17 Section 6.13.5 Table 169
4029 		 */
4030 		add_desc_len = (24 + desc_len);
4031 
4032 		off += desc_len;
4033 		add_len += add_desc_len;
4034 	}
4035 	spin_unlock(&pr_tmpl->registration_lock);
4036 	/*
4037 	 * Set ADDITIONAL_LENGTH
4038 	 */
4039 	buf[4] = ((add_len >> 24) & 0xff);
4040 	buf[5] = ((add_len >> 16) & 0xff);
4041 	buf[6] = ((add_len >> 8) & 0xff);
4042 	buf[7] = (add_len & 0xff);
4043 
4044 	transport_kunmap_data_sg(cmd);
4045 
4046 	return 0;
4047 }
4048 
4049 sense_reason_t
4050 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4051 {
4052 	sense_reason_t ret;
4053 
4054 	/*
4055 	 * Following spc2r20 5.5.1 Reservations overview:
4056 	 *
4057 	 * If a logical unit has been reserved by any RESERVE command and is
4058 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4059 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4060 	 * initiator or service action and shall terminate with a RESERVATION
4061 	 * CONFLICT status.
4062 	 */
4063 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4064 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4065 			" SPC-2 reservation is held, returning"
4066 			" RESERVATION_CONFLICT\n");
4067 		return TCM_RESERVATION_CONFLICT;
4068 	}
4069 
4070 	switch (cmd->t_task_cdb[1] & 0x1f) {
4071 	case PRI_READ_KEYS:
4072 		ret = core_scsi3_pri_read_keys(cmd);
4073 		break;
4074 	case PRI_READ_RESERVATION:
4075 		ret = core_scsi3_pri_read_reservation(cmd);
4076 		break;
4077 	case PRI_REPORT_CAPABILITIES:
4078 		ret = core_scsi3_pri_report_capabilities(cmd);
4079 		break;
4080 	case PRI_READ_FULL_STATUS:
4081 		ret = core_scsi3_pri_read_full_status(cmd);
4082 		break;
4083 	default:
4084 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4085 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4086 		return TCM_INVALID_CDB_FIELD;
4087 	}
4088 
4089 	if (!ret)
4090 		target_complete_cmd(cmd, GOOD);
4091 	return ret;
4092 }
4093 
4094 sense_reason_t
4095 target_check_reservation(struct se_cmd *cmd)
4096 {
4097 	struct se_device *dev = cmd->se_dev;
4098 	sense_reason_t ret;
4099 
4100 	if (!cmd->se_sess)
4101 		return 0;
4102 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4103 		return 0;
4104 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
4105 		return 0;
4106 
4107 	spin_lock(&dev->dev_reservation_lock);
4108 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4109 		ret = target_scsi2_reservation_check(cmd);
4110 	else
4111 		ret = target_scsi3_pr_reservation_check(cmd);
4112 	spin_unlock(&dev->dev_reservation_lock);
4113 
4114 	return ret;
4115 }
4116