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