1 /*******************************************************************************
2  * Filename:  target_core_pr.c
3  *
4  * This file contains SPC-3 compliant persistent reservations and
5  * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
6  *
7  * (c) Copyright 2009-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24  *
25  ******************************************************************************/
26 
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/list.h>
30 #include <linux/vmalloc.h>
31 #include <linux/file.h>
32 #include <linux/fcntl.h>
33 #include <linux/fs.h>
34 #include <scsi/scsi_proto.h>
35 #include <asm/unaligned.h>
36 
37 #include <target/target_core_base.h>
38 #include <target/target_core_backend.h>
39 #include <target/target_core_fabric.h>
40 
41 #include "target_core_internal.h"
42 #include "target_core_pr.h"
43 #include "target_core_ua.h"
44 
45 /*
46  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
47  */
48 struct pr_transport_id_holder {
49 	struct t10_pr_registration *dest_pr_reg;
50 	struct se_portal_group *dest_tpg;
51 	struct se_node_acl *dest_node_acl;
52 	struct se_dev_entry *dest_se_deve;
53 	struct list_head dest_list;
54 };
55 
56 void core_pr_dump_initiator_port(
57 	struct t10_pr_registration *pr_reg,
58 	char *buf,
59 	u32 size)
60 {
61 	if (!pr_reg->isid_present_at_reg) {
62 		buf[0] = '\0';
63 		return;
64 	}
65 
66 	snprintf(buf, size, ",i,0x%s", pr_reg->pr_reg_isid);
67 }
68 
69 enum register_type {
70 	REGISTER,
71 	REGISTER_AND_IGNORE_EXISTING_KEY,
72 	REGISTER_AND_MOVE,
73 };
74 
75 enum preempt_type {
76 	PREEMPT,
77 	PREEMPT_AND_ABORT,
78 };
79 
80 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
81 					      struct t10_pr_registration *, int, int);
82 
83 static int is_reservation_holder(
84 	struct t10_pr_registration *pr_res_holder,
85 	struct t10_pr_registration *pr_reg)
86 {
87 	int pr_res_type;
88 
89 	if (pr_res_holder) {
90 		pr_res_type = pr_res_holder->pr_res_type;
91 
92 		return pr_res_holder == pr_reg ||
93 		       pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
94 		       pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG;
95 	}
96 	return 0;
97 }
98 
99 static sense_reason_t
100 target_scsi2_reservation_check(struct se_cmd *cmd)
101 {
102 	struct se_device *dev = cmd->se_dev;
103 	struct se_session *sess = cmd->se_sess;
104 
105 	switch (cmd->t_task_cdb[0]) {
106 	case INQUIRY:
107 	case RELEASE:
108 	case RELEASE_10:
109 		return 0;
110 	default:
111 		break;
112 	}
113 
114 	if (!dev->dev_reserved_node_acl || !sess)
115 		return 0;
116 
117 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
118 		return TCM_RESERVATION_CONFLICT;
119 
120 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
121 		if (dev->dev_res_bin_isid != sess->sess_bin_isid)
122 			return TCM_RESERVATION_CONFLICT;
123 	}
124 
125 	return 0;
126 }
127 
128 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
129 					struct se_node_acl *, struct se_session *);
130 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
131 
132 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
133 {
134 	struct se_session *se_sess = cmd->se_sess;
135 	struct se_device *dev = cmd->se_dev;
136 	struct t10_pr_registration *pr_reg;
137 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
138 	int conflict = 0;
139 
140 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
141 			se_sess);
142 	if (pr_reg) {
143 		/*
144 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
145 		 * behavior
146 		 *
147 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
148 		 * status, but no reservation shall be established and the
149 		 * persistent reservation shall not be changed, if the command
150 		 * is received from a) and b) below.
151 		 *
152 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
153 		 * status, but the persistent reservation shall not be released,
154 		 * if the command is received from a) and b)
155 		 *
156 		 * a) An I_T nexus that is a persistent reservation holder; or
157 		 * b) An I_T nexus that is registered if a registrants only or
158 		 *    all registrants type persistent reservation is present.
159 		 *
160 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
161 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
162 		 * as defined in SPC-2.
163 		 */
164 		if (pr_reg->pr_res_holder) {
165 			core_scsi3_put_pr_reg(pr_reg);
166 			return 1;
167 		}
168 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
169 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
170 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
171 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
172 			core_scsi3_put_pr_reg(pr_reg);
173 			return 1;
174 		}
175 		core_scsi3_put_pr_reg(pr_reg);
176 		conflict = 1;
177 	} else {
178 		/*
179 		 * Following spc2r20 5.5.1 Reservations overview:
180 		 *
181 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
182 		 * command with the REGISTER or the REGISTER AND IGNORE
183 		 * EXISTING KEY service action and is still registered by any
184 		 * initiator, all RESERVE commands and all RELEASE commands
185 		 * regardless of initiator shall conflict and shall terminate
186 		 * with a RESERVATION CONFLICT status.
187 		 */
188 		spin_lock(&pr_tmpl->registration_lock);
189 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
190 		spin_unlock(&pr_tmpl->registration_lock);
191 	}
192 
193 	if (conflict) {
194 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
195 			" while active SPC-3 registrations exist,"
196 			" returning RESERVATION_CONFLICT\n");
197 		return -EBUSY;
198 	}
199 
200 	return 0;
201 }
202 
203 sense_reason_t
204 target_scsi2_reservation_release(struct se_cmd *cmd)
205 {
206 	struct se_device *dev = cmd->se_dev;
207 	struct se_session *sess = cmd->se_sess;
208 	struct se_portal_group *tpg;
209 	int rc;
210 
211 	if (!sess || !sess->se_tpg)
212 		goto out;
213 	rc = target_check_scsi2_reservation_conflict(cmd);
214 	if (rc == 1)
215 		goto out;
216 	if (rc < 0)
217 		return TCM_RESERVATION_CONFLICT;
218 
219 	spin_lock(&dev->dev_reservation_lock);
220 	if (!dev->dev_reserved_node_acl || !sess)
221 		goto out_unlock;
222 
223 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
224 		goto out_unlock;
225 
226 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
227 		goto out_unlock;
228 
229 	dev->dev_reserved_node_acl = NULL;
230 	dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
231 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
232 		dev->dev_res_bin_isid = 0;
233 		dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS_WITH_ISID;
234 	}
235 	tpg = sess->se_tpg;
236 	pr_debug("SCSI-2 Released reservation for %s LUN: %llu ->"
237 		" MAPPED LUN: %llu for %s\n",
238 		tpg->se_tpg_tfo->fabric_name,
239 		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
240 		sess->se_node_acl->initiatorname);
241 
242 out_unlock:
243 	spin_unlock(&dev->dev_reservation_lock);
244 out:
245 	target_complete_cmd(cmd, GOOD);
246 	return 0;
247 }
248 
249 sense_reason_t
250 target_scsi2_reservation_reserve(struct se_cmd *cmd)
251 {
252 	struct se_device *dev = cmd->se_dev;
253 	struct se_session *sess = cmd->se_sess;
254 	struct se_portal_group *tpg;
255 	sense_reason_t ret = 0;
256 	int rc;
257 
258 	if ((cmd->t_task_cdb[1] & 0x01) &&
259 	    (cmd->t_task_cdb[1] & 0x02)) {
260 		pr_err("LongIO and Obsolete Bits set, returning ILLEGAL_REQUEST\n");
261 		return TCM_UNSUPPORTED_SCSI_OPCODE;
262 	}
263 	/*
264 	 * This is currently the case for target_core_mod passthrough struct se_cmd
265 	 * ops
266 	 */
267 	if (!sess || !sess->se_tpg)
268 		goto out;
269 	rc = target_check_scsi2_reservation_conflict(cmd);
270 	if (rc == 1)
271 		goto out;
272 
273 	if (rc < 0)
274 		return TCM_RESERVATION_CONFLICT;
275 
276 	tpg = sess->se_tpg;
277 	spin_lock(&dev->dev_reservation_lock);
278 	if (dev->dev_reserved_node_acl &&
279 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
280 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
281 			tpg->se_tpg_tfo->fabric_name);
282 		pr_err("Original reserver LUN: %llu %s\n",
283 			cmd->se_lun->unpacked_lun,
284 			dev->dev_reserved_node_acl->initiatorname);
285 		pr_err("Current attempt - LUN: %llu -> MAPPED LUN: %llu"
286 			" from %s \n", cmd->se_lun->unpacked_lun,
287 			cmd->orig_fe_lun,
288 			sess->se_node_acl->initiatorname);
289 		ret = TCM_RESERVATION_CONFLICT;
290 		goto out_unlock;
291 	}
292 
293 	dev->dev_reserved_node_acl = sess->se_node_acl;
294 	dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS;
295 	if (sess->sess_bin_isid != 0) {
296 		dev->dev_res_bin_isid = sess->sess_bin_isid;
297 		dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS_WITH_ISID;
298 	}
299 	pr_debug("SCSI-2 Reserved %s LUN: %llu -> MAPPED LUN: %llu"
300 		" for %s\n", tpg->se_tpg_tfo->fabric_name,
301 		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
302 		sess->se_node_acl->initiatorname);
303 
304 out_unlock:
305 	spin_unlock(&dev->dev_reservation_lock);
306 out:
307 	if (!ret)
308 		target_complete_cmd(cmd, GOOD);
309 	return ret;
310 }
311 
312 
313 /*
314  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
315  *
316  * This function is called by those initiator ports who are *NOT*
317  * the active PR reservation holder when a reservation is present.
318  */
319 static int core_scsi3_pr_seq_non_holder(struct se_cmd *cmd, u32 pr_reg_type,
320 					bool isid_mismatch)
321 {
322 	unsigned char *cdb = cmd->t_task_cdb;
323 	struct se_session *se_sess = cmd->se_sess;
324 	struct se_node_acl *nacl = se_sess->se_node_acl;
325 	int other_cdb = 0;
326 	int registered_nexus = 0, ret = 1; /* Conflict by default */
327 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
328 	int we = 0; /* Write Exclusive */
329 	int legacy = 0; /* Act like a legacy device and return
330 			 * RESERVATION CONFLICT on some CDBs */
331 
332 	if (isid_mismatch) {
333 		registered_nexus = 0;
334 	} else {
335 		struct se_dev_entry *se_deve;
336 
337 		rcu_read_lock();
338 		se_deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
339 		if (se_deve)
340 			registered_nexus = test_bit(DEF_PR_REG_ACTIVE,
341 						    &se_deve->deve_flags);
342 		rcu_read_unlock();
343 	}
344 
345 	switch (pr_reg_type) {
346 	case PR_TYPE_WRITE_EXCLUSIVE:
347 		we = 1;
348 	case PR_TYPE_EXCLUSIVE_ACCESS:
349 		/*
350 		 * Some commands are only allowed for the persistent reservation
351 		 * holder.
352 		 */
353 		break;
354 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
355 		we = 1;
356 		/* fall through */
357 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
358 		/*
359 		 * Some commands are only allowed for registered I_T Nexuses.
360 		 */
361 		reg_only = 1;
362 		break;
363 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
364 		we = 1;
365 		/* fall through */
366 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
367 		/*
368 		 * Each registered I_T Nexus is a reservation holder.
369 		 */
370 		all_reg = 1;
371 		break;
372 	default:
373 		return -EINVAL;
374 	}
375 	/*
376 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
377 	 */
378 	switch (cdb[0]) {
379 	case SECURITY_PROTOCOL_IN:
380 		if (registered_nexus)
381 			return 0;
382 		ret = (we) ? 0 : 1;
383 		break;
384 	case MODE_SENSE:
385 	case MODE_SENSE_10:
386 	case READ_ATTRIBUTE:
387 	case READ_BUFFER:
388 	case RECEIVE_DIAGNOSTIC:
389 		if (legacy) {
390 			ret = 1;
391 			break;
392 		}
393 		if (registered_nexus) {
394 			ret = 0;
395 			break;
396 		}
397 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
398 		break;
399 	case PERSISTENT_RESERVE_OUT:
400 		/*
401 		 * This follows PERSISTENT_RESERVE_OUT service actions that
402 		 * are allowed in the presence of various reservations.
403 		 * See spc4r17, table 46
404 		 */
405 		switch (cdb[1] & 0x1f) {
406 		case PRO_CLEAR:
407 		case PRO_PREEMPT:
408 		case PRO_PREEMPT_AND_ABORT:
409 			ret = (registered_nexus) ? 0 : 1;
410 			break;
411 		case PRO_REGISTER:
412 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
413 			ret = 0;
414 			break;
415 		case PRO_REGISTER_AND_MOVE:
416 		case PRO_RESERVE:
417 			ret = 1;
418 			break;
419 		case PRO_RELEASE:
420 			ret = (registered_nexus) ? 0 : 1;
421 			break;
422 		default:
423 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
424 				" action: 0x%02x\n", cdb[1] & 0x1f);
425 			return -EINVAL;
426 		}
427 		break;
428 	case RELEASE:
429 	case RELEASE_10:
430 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
431 		ret = 0;
432 		break;
433 	case RESERVE:
434 	case RESERVE_10:
435 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
436 		ret = 0;
437 		break;
438 	case TEST_UNIT_READY:
439 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
440 		break;
441 	case MAINTENANCE_IN:
442 		switch (cdb[1] & 0x1f) {
443 		case MI_MANAGEMENT_PROTOCOL_IN:
444 			if (registered_nexus) {
445 				ret = 0;
446 				break;
447 			}
448 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
449 			break;
450 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
451 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
452 			if (legacy) {
453 				ret = 1;
454 				break;
455 			}
456 			if (registered_nexus) {
457 				ret = 0;
458 				break;
459 			}
460 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
461 			break;
462 		case MI_REPORT_ALIASES:
463 		case MI_REPORT_IDENTIFYING_INFORMATION:
464 		case MI_REPORT_PRIORITY:
465 		case MI_REPORT_TARGET_PGS:
466 		case MI_REPORT_TIMESTAMP:
467 			ret = 0; /* Allowed */
468 			break;
469 		default:
470 			pr_err("Unknown MI Service Action: 0x%02x\n",
471 				(cdb[1] & 0x1f));
472 			return -EINVAL;
473 		}
474 		break;
475 	case ACCESS_CONTROL_IN:
476 	case ACCESS_CONTROL_OUT:
477 	case INQUIRY:
478 	case LOG_SENSE:
479 	case SERVICE_ACTION_IN_12:
480 	case REPORT_LUNS:
481 	case REQUEST_SENSE:
482 	case PERSISTENT_RESERVE_IN:
483 		ret = 0; /*/ Allowed CDBs */
484 		break;
485 	default:
486 		other_cdb = 1;
487 		break;
488 	}
489 	/*
490 	 * Case where the CDB is explicitly allowed in the above switch
491 	 * statement.
492 	 */
493 	if (!ret && !other_cdb) {
494 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
495 			" reservation holder\n", cdb[0],
496 			core_scsi3_pr_dump_type(pr_reg_type));
497 
498 		return ret;
499 	}
500 	/*
501 	 * Check if write exclusive initiator ports *NOT* holding the
502 	 * WRITE_EXCLUSIVE_* reservation.
503 	 */
504 	if (we && !registered_nexus) {
505 		if (cmd->data_direction == DMA_TO_DEVICE) {
506 			/*
507 			 * Conflict for write exclusive
508 			 */
509 			pr_debug("%s Conflict for unregistered nexus"
510 				" %s CDB: 0x%02x to %s reservation\n",
511 				transport_dump_cmd_direction(cmd),
512 				se_sess->se_node_acl->initiatorname, cdb[0],
513 				core_scsi3_pr_dump_type(pr_reg_type));
514 			return 1;
515 		} else {
516 			/*
517 			 * Allow non WRITE CDBs for all Write Exclusive
518 			 * PR TYPEs to pass for registered and
519 			 * non-registered_nexuxes NOT holding the reservation.
520 			 *
521 			 * We only make noise for the unregisterd nexuses,
522 			 * as we expect registered non-reservation holding
523 			 * nexuses to issue CDBs.
524 			 */
525 
526 			if (!registered_nexus) {
527 				pr_debug("Allowing implicit CDB: 0x%02x"
528 					" for %s reservation on unregistered"
529 					" nexus\n", cdb[0],
530 					core_scsi3_pr_dump_type(pr_reg_type));
531 			}
532 
533 			return 0;
534 		}
535 	} else if ((reg_only) || (all_reg)) {
536 		if (registered_nexus) {
537 			/*
538 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
539 			 * allow commands from registered nexuses.
540 			 */
541 
542 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
543 				" reservation\n", cdb[0],
544 				core_scsi3_pr_dump_type(pr_reg_type));
545 
546 			return 0;
547 		}
548        } else if (we && registered_nexus) {
549                /*
550                 * Reads are allowed for Write Exclusive locks
551                 * from all registrants.
552                 */
553                if (cmd->data_direction == DMA_FROM_DEVICE) {
554                        pr_debug("Allowing READ CDB: 0x%02x for %s"
555                                " reservation\n", cdb[0],
556                                core_scsi3_pr_dump_type(pr_reg_type));
557 
558                        return 0;
559                }
560 	}
561 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
562 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
563 		(registered_nexus) ? "" : "un",
564 		se_sess->se_node_acl->initiatorname, cdb[0],
565 		core_scsi3_pr_dump_type(pr_reg_type));
566 
567 	return 1; /* Conflict by default */
568 }
569 
570 static sense_reason_t
571 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
572 {
573 	struct se_device *dev = cmd->se_dev;
574 	struct se_session *sess = cmd->se_sess;
575 	u32 pr_reg_type;
576 	bool isid_mismatch = false;
577 
578 	if (!dev->dev_pr_res_holder)
579 		return 0;
580 
581 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
582 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
583 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
584 		goto check_nonholder;
585 
586 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
587 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
588 		    sess->sess_bin_isid) {
589 			isid_mismatch = true;
590 			goto check_nonholder;
591 		}
592 	}
593 
594 	return 0;
595 
596 check_nonholder:
597 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type, isid_mismatch))
598 		return TCM_RESERVATION_CONFLICT;
599 	return 0;
600 }
601 
602 static u32 core_scsi3_pr_generation(struct se_device *dev)
603 {
604 	u32 prg;
605 
606 	/*
607 	 * PRGeneration field shall contain the value of a 32-bit wrapping
608 	 * counter mainted by the device server.
609 	 *
610 	 * Note that this is done regardless of Active Persist across
611 	 * Target PowerLoss (APTPL)
612 	 *
613 	 * See spc4r17 section 6.3.12 READ_KEYS service action
614 	 */
615 	spin_lock(&dev->dev_reservation_lock);
616 	prg = dev->t10_pr.pr_generation++;
617 	spin_unlock(&dev->dev_reservation_lock);
618 
619 	return prg;
620 }
621 
622 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
623 	struct se_device *dev,
624 	struct se_node_acl *nacl,
625 	struct se_lun *lun,
626 	struct se_dev_entry *dest_deve,
627 	u64 mapped_lun,
628 	unsigned char *isid,
629 	u64 sa_res_key,
630 	int all_tg_pt,
631 	int aptpl)
632 {
633 	struct t10_pr_registration *pr_reg;
634 
635 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
636 	if (!pr_reg) {
637 		pr_err("Unable to allocate struct t10_pr_registration\n");
638 		return NULL;
639 	}
640 
641 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
642 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
643 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
644 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
645 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
646 	atomic_set(&pr_reg->pr_res_holders, 0);
647 	pr_reg->pr_reg_nacl = nacl;
648 	/*
649 	 * For destination registrations for ALL_TG_PT=1 and SPEC_I_PT=1,
650 	 * the se_dev_entry->pr_ref will have been already obtained by
651 	 * core_get_se_deve_from_rtpi() or __core_scsi3_alloc_registration().
652 	 *
653 	 * Otherwise, locate se_dev_entry now and obtain a reference until
654 	 * registration completes in __core_scsi3_add_registration().
655 	 */
656 	if (dest_deve) {
657 		pr_reg->pr_reg_deve = dest_deve;
658 	} else {
659 		rcu_read_lock();
660 		pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
661 		if (!pr_reg->pr_reg_deve) {
662 			rcu_read_unlock();
663 			pr_err("Unable to locate PR deve %s mapped_lun: %llu\n",
664 				nacl->initiatorname, mapped_lun);
665 			kmem_cache_free(t10_pr_reg_cache, pr_reg);
666 			return NULL;
667 		}
668 		kref_get(&pr_reg->pr_reg_deve->pr_kref);
669 		rcu_read_unlock();
670 	}
671 	pr_reg->pr_res_mapped_lun = mapped_lun;
672 	pr_reg->pr_aptpl_target_lun = lun->unpacked_lun;
673 	pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
674 	pr_reg->pr_res_key = sa_res_key;
675 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
676 	pr_reg->pr_reg_aptpl = aptpl;
677 	/*
678 	 * If an ISID value for this SCSI Initiator Port exists,
679 	 * save it to the registration now.
680 	 */
681 	if (isid != NULL) {
682 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
683 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
684 		pr_reg->isid_present_at_reg = 1;
685 	}
686 
687 	return pr_reg;
688 }
689 
690 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
691 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
692 
693 /*
694  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
695  * modes.
696  */
697 static struct t10_pr_registration *__core_scsi3_alloc_registration(
698 	struct se_device *dev,
699 	struct se_node_acl *nacl,
700 	struct se_lun *lun,
701 	struct se_dev_entry *deve,
702 	u64 mapped_lun,
703 	unsigned char *isid,
704 	u64 sa_res_key,
705 	int all_tg_pt,
706 	int aptpl)
707 {
708 	struct se_dev_entry *deve_tmp;
709 	struct se_node_acl *nacl_tmp;
710 	struct se_lun_acl *lacl_tmp;
711 	struct se_lun *lun_tmp, *next, *dest_lun;
712 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
713 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
714 	int ret;
715 	/*
716 	 * Create a registration for the I_T Nexus upon which the
717 	 * PROUT REGISTER was received.
718 	 */
719 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, lun, deve, mapped_lun,
720 						    isid, sa_res_key, all_tg_pt,
721 						    aptpl);
722 	if (!pr_reg)
723 		return NULL;
724 	/*
725 	 * Return pointer to pr_reg for ALL_TG_PT=0
726 	 */
727 	if (!all_tg_pt)
728 		return pr_reg;
729 	/*
730 	 * Create list of matching SCSI Initiator Port registrations
731 	 * for ALL_TG_PT=1
732 	 */
733 	spin_lock(&dev->se_port_lock);
734 	list_for_each_entry_safe(lun_tmp, next, &dev->dev_sep_list, lun_dev_link) {
735 		if (!percpu_ref_tryget_live(&lun_tmp->lun_ref))
736 			continue;
737 		spin_unlock(&dev->se_port_lock);
738 
739 		spin_lock(&lun_tmp->lun_deve_lock);
740 		list_for_each_entry(deve_tmp, &lun_tmp->lun_deve_list, lun_link) {
741 			/*
742 			 * This pointer will be NULL for demo mode MappedLUNs
743 			 * that have not been make explicit via a ConfigFS
744 			 * MappedLUN group for the SCSI Initiator Node ACL.
745 			 */
746 			if (!deve_tmp->se_lun_acl)
747 				continue;
748 
749 			lacl_tmp = rcu_dereference_check(deve_tmp->se_lun_acl,
750 						lockdep_is_held(&lun_tmp->lun_deve_lock));
751 			nacl_tmp = lacl_tmp->se_lun_nacl;
752 			/*
753 			 * Skip the matching struct se_node_acl that is allocated
754 			 * above..
755 			 */
756 			if (nacl == nacl_tmp)
757 				continue;
758 			/*
759 			 * Only perform PR registrations for target ports on
760 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
761 			 * arrived.
762 			 */
763 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
764 				continue;
765 			/*
766 			 * Look for a matching Initiator Node ACL in ASCII format
767 			 */
768 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
769 				continue;
770 
771 			kref_get(&deve_tmp->pr_kref);
772 			spin_unlock(&lun_tmp->lun_deve_lock);
773 			/*
774 			 * Grab a configfs group dependency that is released
775 			 * for the exception path at label out: below, or upon
776 			 * completion of adding ALL_TG_PT=1 registrations in
777 			 * __core_scsi3_add_registration()
778 			 */
779 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
780 			if (ret < 0) {
781 				pr_err("core_scsi3_lunacl_depend"
782 						"_item() failed\n");
783 				percpu_ref_put(&lun_tmp->lun_ref);
784 				kref_put(&deve_tmp->pr_kref, target_pr_kref_release);
785 				goto out;
786 			}
787 			/*
788 			 * Located a matching SCSI Initiator Port on a different
789 			 * port, allocate the pr_reg_atp and attach it to the
790 			 * pr_reg->pr_reg_atp_list that will be processed once
791 			 * the original *pr_reg is processed in
792 			 * __core_scsi3_add_registration()
793 			 */
794 			dest_lun = rcu_dereference_check(deve_tmp->se_lun,
795 				kref_read(&deve_tmp->pr_kref) != 0);
796 
797 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
798 						nacl_tmp, dest_lun, deve_tmp,
799 						deve_tmp->mapped_lun, NULL,
800 						sa_res_key, all_tg_pt, aptpl);
801 			if (!pr_reg_atp) {
802 				percpu_ref_put(&lun_tmp->lun_ref);
803 				core_scsi3_lunacl_undepend_item(deve_tmp);
804 				goto out;
805 			}
806 
807 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
808 				      &pr_reg->pr_reg_atp_list);
809 			spin_lock(&lun_tmp->lun_deve_lock);
810 		}
811 		spin_unlock(&lun_tmp->lun_deve_lock);
812 
813 		spin_lock(&dev->se_port_lock);
814 		percpu_ref_put(&lun_tmp->lun_ref);
815 	}
816 	spin_unlock(&dev->se_port_lock);
817 
818 	return pr_reg;
819 out:
820 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
821 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
822 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
823 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
824 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
825 	}
826 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
827 	return NULL;
828 }
829 
830 int core_scsi3_alloc_aptpl_registration(
831 	struct t10_reservation *pr_tmpl,
832 	u64 sa_res_key,
833 	unsigned char *i_port,
834 	unsigned char *isid,
835 	u64 mapped_lun,
836 	unsigned char *t_port,
837 	u16 tpgt,
838 	u64 target_lun,
839 	int res_holder,
840 	int all_tg_pt,
841 	u8 type)
842 {
843 	struct t10_pr_registration *pr_reg;
844 
845 	if (!i_port || !t_port || !sa_res_key) {
846 		pr_err("Illegal parameters for APTPL registration\n");
847 		return -EINVAL;
848 	}
849 
850 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
851 	if (!pr_reg) {
852 		pr_err("Unable to allocate struct t10_pr_registration\n");
853 		return -ENOMEM;
854 	}
855 
856 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
857 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
858 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
859 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
860 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
861 	atomic_set(&pr_reg->pr_res_holders, 0);
862 	pr_reg->pr_reg_nacl = NULL;
863 	pr_reg->pr_reg_deve = NULL;
864 	pr_reg->pr_res_mapped_lun = mapped_lun;
865 	pr_reg->pr_aptpl_target_lun = target_lun;
866 	pr_reg->pr_res_key = sa_res_key;
867 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
868 	pr_reg->pr_reg_aptpl = 1;
869 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
870 	pr_reg->pr_res_type = type;
871 	/*
872 	 * If an ISID value had been saved in APTPL metadata for this
873 	 * SCSI Initiator Port, restore it now.
874 	 */
875 	if (isid != NULL) {
876 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
877 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
878 		pr_reg->isid_present_at_reg = 1;
879 	}
880 	/*
881 	 * Copy the i_port and t_port information from caller.
882 	 */
883 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
884 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
885 	pr_reg->pr_reg_tpgt = tpgt;
886 	/*
887 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
888 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
889 	 * the Initiator Node LUN ACL from the fabric module is created for
890 	 * this registration.
891 	 */
892 	pr_reg->pr_res_holder = res_holder;
893 
894 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
895 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
896 			" metadata\n", (res_holder) ? "+reservation" : "");
897 	return 0;
898 }
899 
900 static void core_scsi3_aptpl_reserve(
901 	struct se_device *dev,
902 	struct se_portal_group *tpg,
903 	struct se_node_acl *node_acl,
904 	struct t10_pr_registration *pr_reg)
905 {
906 	char i_buf[PR_REG_ISID_ID_LEN];
907 
908 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
909 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
910 
911 	spin_lock(&dev->dev_reservation_lock);
912 	dev->dev_pr_res_holder = pr_reg;
913 	spin_unlock(&dev->dev_reservation_lock);
914 
915 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
916 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
917 		tpg->se_tpg_tfo->fabric_name,
918 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
919 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
920 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
921 		tpg->se_tpg_tfo->fabric_name, node_acl->initiatorname,
922 		i_buf);
923 }
924 
925 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
926 				struct t10_pr_registration *, enum register_type, int);
927 
928 static int __core_scsi3_check_aptpl_registration(
929 	struct se_device *dev,
930 	struct se_portal_group *tpg,
931 	struct se_lun *lun,
932 	u64 target_lun,
933 	struct se_node_acl *nacl,
934 	u64 mapped_lun)
935 {
936 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
937 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
938 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
939 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
940 	u16 tpgt;
941 
942 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
943 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
944 	/*
945 	 * Copy Initiator Port information from struct se_node_acl
946 	 */
947 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
948 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
949 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
950 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
951 	/*
952 	 * Look for the matching registrations+reservation from those
953 	 * created from APTPL metadata.  Note that multiple registrations
954 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
955 	 * TransportIDs.
956 	 */
957 	spin_lock(&pr_tmpl->aptpl_reg_lock);
958 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
959 				pr_reg_aptpl_list) {
960 
961 		if (!strcmp(pr_reg->pr_iport, i_port) &&
962 		     (pr_reg->pr_res_mapped_lun == mapped_lun) &&
963 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
964 		     (pr_reg->pr_reg_tpgt == tpgt) &&
965 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
966 			/*
967 			 * Obtain the ->pr_reg_deve pointer + reference, that
968 			 * is released by __core_scsi3_add_registration() below.
969 			 */
970 			rcu_read_lock();
971 			pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
972 			if (!pr_reg->pr_reg_deve) {
973 				pr_err("Unable to locate PR APTPL %s mapped_lun:"
974 					" %llu\n", nacl->initiatorname, mapped_lun);
975 				rcu_read_unlock();
976 				continue;
977 			}
978 			kref_get(&pr_reg->pr_reg_deve->pr_kref);
979 			rcu_read_unlock();
980 
981 			pr_reg->pr_reg_nacl = nacl;
982 			pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
983 			list_del(&pr_reg->pr_reg_aptpl_list);
984 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
985 			/*
986 			 * At this point all of the pointers in *pr_reg will
987 			 * be setup, so go ahead and add the registration.
988 			 */
989 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
990 			/*
991 			 * If this registration is the reservation holder,
992 			 * make that happen now..
993 			 */
994 			if (pr_reg->pr_res_holder)
995 				core_scsi3_aptpl_reserve(dev, tpg,
996 						nacl, pr_reg);
997 			/*
998 			 * Reenable pr_aptpl_active to accept new metadata
999 			 * updates once the SCSI device is active again..
1000 			 */
1001 			spin_lock(&pr_tmpl->aptpl_reg_lock);
1002 			pr_tmpl->pr_aptpl_active = 1;
1003 		}
1004 	}
1005 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1006 
1007 	return 0;
1008 }
1009 
1010 int core_scsi3_check_aptpl_registration(
1011 	struct se_device *dev,
1012 	struct se_portal_group *tpg,
1013 	struct se_lun *lun,
1014 	struct se_node_acl *nacl,
1015 	u64 mapped_lun)
1016 {
1017 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
1018 		return 0;
1019 
1020 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
1021 						     lun->unpacked_lun, nacl,
1022 						     mapped_lun);
1023 }
1024 
1025 static void __core_scsi3_dump_registration(
1026 	const struct target_core_fabric_ops *tfo,
1027 	struct se_device *dev,
1028 	struct se_node_acl *nacl,
1029 	struct t10_pr_registration *pr_reg,
1030 	enum register_type register_type)
1031 {
1032 	struct se_portal_group *se_tpg = nacl->se_tpg;
1033 	char i_buf[PR_REG_ISID_ID_LEN];
1034 
1035 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
1036 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1037 
1038 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1039 		" Node: %s%s\n", tfo->fabric_name, (register_type == REGISTER_AND_MOVE) ?
1040 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
1041 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1042 		i_buf);
1043 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1044 		 tfo->fabric_name, tfo->tpg_get_wwn(se_tpg),
1045 		tfo->tpg_get_tag(se_tpg));
1046 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1047 		" Port(s)\n",  tfo->fabric_name,
1048 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1049 		dev->transport->name);
1050 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1051 		" 0x%08x  APTPL: %d\n", tfo->fabric_name,
1052 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1053 		pr_reg->pr_reg_aptpl);
1054 }
1055 
1056 static void __core_scsi3_add_registration(
1057 	struct se_device *dev,
1058 	struct se_node_acl *nacl,
1059 	struct t10_pr_registration *pr_reg,
1060 	enum register_type register_type,
1061 	int register_move)
1062 {
1063 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1064 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1065 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1066 	struct se_dev_entry *deve;
1067 
1068 	/*
1069 	 * Increment PRgeneration counter for struct se_device upon a successful
1070 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1071 	 *
1072 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1073 	 * action, the struct se_device->dev_reservation_lock will already be held,
1074 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1075 	 * for the REGISTER.
1076 	 */
1077 	pr_reg->pr_res_generation = (register_move) ?
1078 			dev->t10_pr.pr_generation++ :
1079 			core_scsi3_pr_generation(dev);
1080 
1081 	spin_lock(&pr_tmpl->registration_lock);
1082 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1083 
1084 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1085 	spin_unlock(&pr_tmpl->registration_lock);
1086 	/*
1087 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1088 	 */
1089 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1090 		goto out;
1091 	/*
1092 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1093 	 * allocated in __core_scsi3_alloc_registration()
1094 	 */
1095 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1096 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1097 		struct se_node_acl *nacl_tmp = pr_reg_tmp->pr_reg_nacl;
1098 
1099 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1100 
1101 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1102 
1103 		spin_lock(&pr_tmpl->registration_lock);
1104 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1105 			      &pr_tmpl->registration_list);
1106 
1107 		__core_scsi3_dump_registration(tfo, dev, nacl_tmp, pr_reg_tmp,
1108 					       register_type);
1109 		spin_unlock(&pr_tmpl->registration_lock);
1110 		/*
1111 		 * Drop configfs group dependency reference and deve->pr_kref
1112 		 * obtained from  __core_scsi3_alloc_registration() code.
1113 		 */
1114 		rcu_read_lock();
1115 		deve = pr_reg_tmp->pr_reg_deve;
1116 		if (deve) {
1117 			set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1118 			core_scsi3_lunacl_undepend_item(deve);
1119 			pr_reg_tmp->pr_reg_deve = NULL;
1120 		}
1121 		rcu_read_unlock();
1122 	}
1123 out:
1124 	/*
1125 	 * Drop deve->pr_kref obtained in __core_scsi3_do_alloc_registration()
1126 	 */
1127 	rcu_read_lock();
1128 	deve = pr_reg->pr_reg_deve;
1129 	if (deve) {
1130 		set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1131 		kref_put(&deve->pr_kref, target_pr_kref_release);
1132 		pr_reg->pr_reg_deve = NULL;
1133 	}
1134 	rcu_read_unlock();
1135 }
1136 
1137 static int core_scsi3_alloc_registration(
1138 	struct se_device *dev,
1139 	struct se_node_acl *nacl,
1140 	struct se_lun *lun,
1141 	struct se_dev_entry *deve,
1142 	u64 mapped_lun,
1143 	unsigned char *isid,
1144 	u64 sa_res_key,
1145 	int all_tg_pt,
1146 	int aptpl,
1147 	enum register_type register_type,
1148 	int register_move)
1149 {
1150 	struct t10_pr_registration *pr_reg;
1151 
1152 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, lun, deve, mapped_lun,
1153 						 isid, sa_res_key, all_tg_pt,
1154 						 aptpl);
1155 	if (!pr_reg)
1156 		return -EPERM;
1157 
1158 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1159 			register_type, register_move);
1160 	return 0;
1161 }
1162 
1163 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1164 	struct se_device *dev,
1165 	struct se_node_acl *nacl,
1166 	unsigned char *isid)
1167 {
1168 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1169 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1170 	struct se_portal_group *tpg;
1171 
1172 	spin_lock(&pr_tmpl->registration_lock);
1173 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1174 			&pr_tmpl->registration_list, pr_reg_list) {
1175 		/*
1176 		 * First look for a matching struct se_node_acl
1177 		 */
1178 		if (pr_reg->pr_reg_nacl != nacl)
1179 			continue;
1180 
1181 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1182 		/*
1183 		 * If this registration does NOT contain a fabric provided
1184 		 * ISID, then we have found a match.
1185 		 */
1186 		if (!pr_reg->isid_present_at_reg) {
1187 			/*
1188 			 * Determine if this SCSI device server requires that
1189 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1190 			 * for fabric modules (iSCSI) requiring them.
1191 			 */
1192 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1193 				if (dev->dev_attrib.enforce_pr_isids)
1194 					continue;
1195 			}
1196 			atomic_inc_mb(&pr_reg->pr_res_holders);
1197 			spin_unlock(&pr_tmpl->registration_lock);
1198 			return pr_reg;
1199 		}
1200 		/*
1201 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1202 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1203 		 * matching ISID to be provided by the local SCSI Initiator Port.
1204 		 */
1205 		if (!isid)
1206 			continue;
1207 		if (strcmp(isid, pr_reg->pr_reg_isid))
1208 			continue;
1209 
1210 		atomic_inc_mb(&pr_reg->pr_res_holders);
1211 		spin_unlock(&pr_tmpl->registration_lock);
1212 		return pr_reg;
1213 	}
1214 	spin_unlock(&pr_tmpl->registration_lock);
1215 
1216 	return NULL;
1217 }
1218 
1219 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1220 	struct se_device *dev,
1221 	struct se_node_acl *nacl,
1222 	struct se_session *sess)
1223 {
1224 	struct se_portal_group *tpg = nacl->se_tpg;
1225 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1226 
1227 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1228 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1229 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1230 					PR_REG_ISID_LEN);
1231 		isid_ptr = &buf[0];
1232 	}
1233 
1234 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1235 }
1236 
1237 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1238 {
1239 	atomic_dec_mb(&pr_reg->pr_res_holders);
1240 }
1241 
1242 static int core_scsi3_check_implicit_release(
1243 	struct se_device *dev,
1244 	struct t10_pr_registration *pr_reg)
1245 {
1246 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1247 	struct t10_pr_registration *pr_res_holder;
1248 	int ret = 0;
1249 
1250 	spin_lock(&dev->dev_reservation_lock);
1251 	pr_res_holder = dev->dev_pr_res_holder;
1252 	if (!pr_res_holder) {
1253 		spin_unlock(&dev->dev_reservation_lock);
1254 		return ret;
1255 	}
1256 	if (pr_res_holder == pr_reg) {
1257 		/*
1258 		 * Perform an implicit RELEASE if the registration that
1259 		 * is being released is holding the reservation.
1260 		 *
1261 		 * From spc4r17, section 5.7.11.1:
1262 		 *
1263 		 * e) If the I_T nexus is the persistent reservation holder
1264 		 *    and the persistent reservation is not an all registrants
1265 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1266 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1267 		 *    service action with the SERVICE ACTION RESERVATION KEY
1268 		 *    field set to zero (see 5.7.11.3).
1269 		 */
1270 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1271 		ret = 1;
1272 		/*
1273 		 * For 'All Registrants' reservation types, all existing
1274 		 * registrations are still processed as reservation holders
1275 		 * in core_scsi3_pr_seq_non_holder() after the initial
1276 		 * reservation holder is implicitly released here.
1277 		 */
1278 	} else if (pr_reg->pr_reg_all_tg_pt &&
1279 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1280 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1281 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1282 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1283 			" UNREGISTER while existing reservation with matching"
1284 			" key 0x%016Lx is present from another SCSI Initiator"
1285 			" Port\n", pr_reg->pr_res_key);
1286 		ret = -EPERM;
1287 	}
1288 	spin_unlock(&dev->dev_reservation_lock);
1289 
1290 	return ret;
1291 }
1292 
1293 static void __core_scsi3_free_registration(
1294 	struct se_device *dev,
1295 	struct t10_pr_registration *pr_reg,
1296 	struct list_head *preempt_and_abort_list,
1297 	int dec_holders)
1298 	__releases(&pr_tmpl->registration_lock)
1299 	__acquires(&pr_tmpl->registration_lock)
1300 {
1301 	const struct target_core_fabric_ops *tfo =
1302 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1303 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1304 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1305 	struct se_dev_entry *deve;
1306 	char i_buf[PR_REG_ISID_ID_LEN];
1307 
1308 	lockdep_assert_held(&pr_tmpl->registration_lock);
1309 
1310 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1311 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1312 
1313 	if (!list_empty(&pr_reg->pr_reg_list))
1314 		list_del(&pr_reg->pr_reg_list);
1315 	/*
1316 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1317 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1318 	 */
1319 	if (dec_holders)
1320 		core_scsi3_put_pr_reg(pr_reg);
1321 
1322 	spin_unlock(&pr_tmpl->registration_lock);
1323 	/*
1324 	 * Wait until all reference from any other I_T nexuses for this
1325 	 * *pr_reg have been released.  Because list_del() is called above,
1326 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1327 	 * count back to zero, and we release *pr_reg.
1328 	 */
1329 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1330 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1331 				tfo->fabric_name);
1332 		cpu_relax();
1333 	}
1334 
1335 	rcu_read_lock();
1336 	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
1337 	if (deve)
1338 		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1339 	rcu_read_unlock();
1340 
1341 	spin_lock(&pr_tmpl->registration_lock);
1342 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1343 		" Node: %s%s\n", tfo->fabric_name,
1344 		pr_reg->pr_reg_nacl->initiatorname,
1345 		i_buf);
1346 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1347 		" Port(s)\n", tfo->fabric_name,
1348 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1349 		dev->transport->name);
1350 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1351 		" 0x%08x\n", tfo->fabric_name, pr_reg->pr_res_key,
1352 		pr_reg->pr_res_generation);
1353 
1354 	if (!preempt_and_abort_list) {
1355 		pr_reg->pr_reg_deve = NULL;
1356 		pr_reg->pr_reg_nacl = NULL;
1357 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1358 		return;
1359 	}
1360 	/*
1361 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1362 	 * are released once the ABORT_TASK_SET has completed..
1363 	 */
1364 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1365 }
1366 
1367 void core_scsi3_free_pr_reg_from_nacl(
1368 	struct se_device *dev,
1369 	struct se_node_acl *nacl)
1370 {
1371 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1372 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1373 	bool free_reg = false;
1374 	/*
1375 	 * If the passed se_node_acl matches the reservation holder,
1376 	 * release the reservation.
1377 	 */
1378 	spin_lock(&dev->dev_reservation_lock);
1379 	pr_res_holder = dev->dev_pr_res_holder;
1380 	if ((pr_res_holder != NULL) &&
1381 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1382 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1383 		free_reg = true;
1384 	}
1385 	spin_unlock(&dev->dev_reservation_lock);
1386 	/*
1387 	 * Release any registration associated with the struct se_node_acl.
1388 	 */
1389 	spin_lock(&pr_tmpl->registration_lock);
1390 	if (pr_res_holder && free_reg)
1391 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1392 
1393 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1394 			&pr_tmpl->registration_list, pr_reg_list) {
1395 
1396 		if (pr_reg->pr_reg_nacl != nacl)
1397 			continue;
1398 
1399 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1400 	}
1401 	spin_unlock(&pr_tmpl->registration_lock);
1402 }
1403 
1404 void core_scsi3_free_all_registrations(
1405 	struct se_device *dev)
1406 {
1407 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1408 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1409 
1410 	spin_lock(&dev->dev_reservation_lock);
1411 	pr_res_holder = dev->dev_pr_res_holder;
1412 	if (pr_res_holder != NULL) {
1413 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1414 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1415 						  pr_res_holder, 0, 0);
1416 	}
1417 	spin_unlock(&dev->dev_reservation_lock);
1418 
1419 	spin_lock(&pr_tmpl->registration_lock);
1420 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1421 			&pr_tmpl->registration_list, pr_reg_list) {
1422 
1423 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1424 	}
1425 	spin_unlock(&pr_tmpl->registration_lock);
1426 
1427 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1428 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1429 				pr_reg_aptpl_list) {
1430 		list_del(&pr_reg->pr_reg_aptpl_list);
1431 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1432 	}
1433 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1434 }
1435 
1436 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1437 {
1438 	return target_depend_item(&tpg->tpg_group.cg_item);
1439 }
1440 
1441 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1442 {
1443 	target_undepend_item(&tpg->tpg_group.cg_item);
1444 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1445 }
1446 
1447 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1448 {
1449 	if (nacl->dynamic_node_acl)
1450 		return 0;
1451 	return target_depend_item(&nacl->acl_group.cg_item);
1452 }
1453 
1454 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1455 {
1456 	if (!nacl->dynamic_node_acl)
1457 		target_undepend_item(&nacl->acl_group.cg_item);
1458 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1459 }
1460 
1461 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1462 {
1463 	struct se_lun_acl *lun_acl;
1464 
1465 	/*
1466 	 * For nacl->dynamic_node_acl=1
1467 	 */
1468 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1469 				kref_read(&se_deve->pr_kref) != 0);
1470 	if (!lun_acl)
1471 		return 0;
1472 
1473 	return target_depend_item(&lun_acl->se_lun_group.cg_item);
1474 }
1475 
1476 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1477 {
1478 	struct se_lun_acl *lun_acl;
1479 
1480 	/*
1481 	 * For nacl->dynamic_node_acl=1
1482 	 */
1483 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1484 				kref_read(&se_deve->pr_kref) != 0);
1485 	if (!lun_acl) {
1486 		kref_put(&se_deve->pr_kref, target_pr_kref_release);
1487 		return;
1488 	}
1489 
1490 	target_undepend_item(&lun_acl->se_lun_group.cg_item);
1491 	kref_put(&se_deve->pr_kref, target_pr_kref_release);
1492 }
1493 
1494 static sense_reason_t
1495 core_scsi3_decode_spec_i_port(
1496 	struct se_cmd *cmd,
1497 	struct se_portal_group *tpg,
1498 	unsigned char *l_isid,
1499 	u64 sa_res_key,
1500 	int all_tg_pt,
1501 	int aptpl)
1502 {
1503 	struct se_device *dev = cmd->se_dev;
1504 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1505 	struct se_session *se_sess = cmd->se_sess;
1506 	struct se_node_acl *dest_node_acl = NULL;
1507 	struct se_dev_entry *dest_se_deve = NULL;
1508 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1509 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1510 	LIST_HEAD(tid_dest_list);
1511 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1512 	unsigned char *buf, *ptr, proto_ident;
1513 	const unsigned char *i_str = NULL;
1514 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1515 	sense_reason_t ret;
1516 	u32 tpdl, tid_len = 0;
1517 	u32 dest_rtpi = 0;
1518 
1519 	/*
1520 	 * Allocate a struct pr_transport_id_holder and setup the
1521 	 * local_node_acl pointer and add to struct list_head tid_dest_list
1522 	 * for add registration processing in the loop of tid_dest_list below.
1523 	 */
1524 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1525 	if (!tidh_new) {
1526 		pr_err("Unable to allocate tidh_new\n");
1527 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1528 	}
1529 	INIT_LIST_HEAD(&tidh_new->dest_list);
1530 	tidh_new->dest_tpg = tpg;
1531 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1532 
1533 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1534 				se_sess->se_node_acl, cmd->se_lun,
1535 				NULL, cmd->orig_fe_lun, l_isid,
1536 				sa_res_key, all_tg_pt, aptpl);
1537 	if (!local_pr_reg) {
1538 		kfree(tidh_new);
1539 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1540 	}
1541 	tidh_new->dest_pr_reg = local_pr_reg;
1542 	/*
1543 	 * The local I_T nexus does not hold any configfs dependances,
1544 	 * so we set tidh_new->dest_se_deve to NULL to prevent the
1545 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1546 	 */
1547 	tidh_new->dest_se_deve = NULL;
1548 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1549 
1550 	if (cmd->data_length < 28) {
1551 		pr_warn("SPC-PR: Received PR OUT parameter list"
1552 			" length too small: %u\n", cmd->data_length);
1553 		ret = TCM_INVALID_PARAMETER_LIST;
1554 		goto out;
1555 	}
1556 
1557 	buf = transport_kmap_data_sg(cmd);
1558 	if (!buf) {
1559 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1560 		goto out;
1561 	}
1562 
1563 	/*
1564 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1565 	 * first extract TransportID Parameter Data Length, and make sure
1566 	 * the value matches up to the SCSI expected data transfer length.
1567 	 */
1568 	tpdl = get_unaligned_be32(&buf[24]);
1569 
1570 	if ((tpdl + 28) != cmd->data_length) {
1571 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1572 			" does not equal CDB data_length: %u\n", tpdl,
1573 			cmd->data_length);
1574 		ret = TCM_INVALID_PARAMETER_LIST;
1575 		goto out_unmap;
1576 	}
1577 	/*
1578 	 * Start processing the received transport IDs using the
1579 	 * receiving I_T Nexus portal's fabric dependent methods to
1580 	 * obtain the SCSI Initiator Port/Device Identifiers.
1581 	 */
1582 	ptr = &buf[28];
1583 
1584 	while (tpdl > 0) {
1585 		struct se_lun *dest_lun, *tmp_lun;
1586 
1587 		proto_ident = (ptr[0] & 0x0f);
1588 		dest_tpg = NULL;
1589 
1590 		spin_lock(&dev->se_port_lock);
1591 		list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
1592 			tmp_tpg = tmp_lun->lun_tpg;
1593 
1594 			/*
1595 			 * Look for the matching proto_ident provided by
1596 			 * the received TransportID
1597 			 */
1598 			if (tmp_tpg->proto_id != proto_ident)
1599 				continue;
1600 			dest_rtpi = tmp_lun->lun_rtpi;
1601 
1602 			i_str = target_parse_pr_out_transport_id(tmp_tpg,
1603 					ptr, &tid_len, &iport_ptr);
1604 			if (!i_str)
1605 				continue;
1606 
1607 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1608 			spin_unlock(&dev->se_port_lock);
1609 
1610 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1611 				pr_err(" core_scsi3_tpg_depend_item()"
1612 					" for tmp_tpg\n");
1613 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1614 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1615 				goto out_unmap;
1616 			}
1617 			/*
1618 			 * Locate the destination initiator ACL to be registered
1619 			 * from the decoded fabric module specific TransportID
1620 			 * at *i_str.
1621 			 */
1622 			mutex_lock(&tmp_tpg->acl_node_mutex);
1623 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1624 						tmp_tpg, i_str);
1625 			if (dest_node_acl)
1626 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1627 			mutex_unlock(&tmp_tpg->acl_node_mutex);
1628 
1629 			if (!dest_node_acl) {
1630 				core_scsi3_tpg_undepend_item(tmp_tpg);
1631 				spin_lock(&dev->se_port_lock);
1632 				continue;
1633 			}
1634 
1635 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1636 				pr_err("configfs_depend_item() failed"
1637 					" for dest_node_acl->acl_group\n");
1638 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1639 				core_scsi3_tpg_undepend_item(tmp_tpg);
1640 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1641 				goto out_unmap;
1642 			}
1643 
1644 			dest_tpg = tmp_tpg;
1645 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1646 				" %s Port RTPI: %hu\n",
1647 				dest_tpg->se_tpg_tfo->fabric_name,
1648 				dest_node_acl->initiatorname, dest_rtpi);
1649 
1650 			spin_lock(&dev->se_port_lock);
1651 			break;
1652 		}
1653 		spin_unlock(&dev->se_port_lock);
1654 
1655 		if (!dest_tpg) {
1656 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1657 					" dest_tpg\n");
1658 			ret = TCM_INVALID_PARAMETER_LIST;
1659 			goto out_unmap;
1660 		}
1661 
1662 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1663 			" tid_len: %d for %s + %s\n",
1664 			dest_tpg->se_tpg_tfo->fabric_name, cmd->data_length,
1665 			tpdl, tid_len, i_str, iport_ptr);
1666 
1667 		if (tid_len > tpdl) {
1668 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1669 				" %u for Transport ID: %s\n", tid_len, ptr);
1670 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1671 			core_scsi3_tpg_undepend_item(dest_tpg);
1672 			ret = TCM_INVALID_PARAMETER_LIST;
1673 			goto out_unmap;
1674 		}
1675 		/*
1676 		 * Locate the desintation struct se_dev_entry pointer for matching
1677 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1678 		 * Target Port.
1679 		 */
1680 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1681 					dest_rtpi);
1682 		if (!dest_se_deve) {
1683 			pr_err("Unable to locate %s dest_se_deve"
1684 				" from destination RTPI: %hu\n",
1685 				dest_tpg->se_tpg_tfo->fabric_name,
1686 				dest_rtpi);
1687 
1688 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1689 			core_scsi3_tpg_undepend_item(dest_tpg);
1690 			ret = TCM_INVALID_PARAMETER_LIST;
1691 			goto out_unmap;
1692 		}
1693 
1694 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1695 			pr_err("core_scsi3_lunacl_depend_item()"
1696 					" failed\n");
1697 			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
1698 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1699 			core_scsi3_tpg_undepend_item(dest_tpg);
1700 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1701 			goto out_unmap;
1702 		}
1703 
1704 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1705 			" dest_se_deve mapped_lun: %llu\n",
1706 			dest_tpg->se_tpg_tfo->fabric_name,
1707 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1708 
1709 		/*
1710 		 * Skip any TransportIDs that already have a registration for
1711 		 * this target port.
1712 		 */
1713 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1714 					iport_ptr);
1715 		if (pr_reg_e) {
1716 			core_scsi3_put_pr_reg(pr_reg_e);
1717 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1718 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1719 			core_scsi3_tpg_undepend_item(dest_tpg);
1720 			ptr += tid_len;
1721 			tpdl -= tid_len;
1722 			tid_len = 0;
1723 			continue;
1724 		}
1725 		/*
1726 		 * Allocate a struct pr_transport_id_holder and setup
1727 		 * the dest_node_acl and dest_se_deve pointers for the
1728 		 * loop below.
1729 		 */
1730 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1731 				GFP_KERNEL);
1732 		if (!tidh_new) {
1733 			pr_err("Unable to allocate tidh_new\n");
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 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1738 			goto out_unmap;
1739 		}
1740 		INIT_LIST_HEAD(&tidh_new->dest_list);
1741 		tidh_new->dest_tpg = dest_tpg;
1742 		tidh_new->dest_node_acl = dest_node_acl;
1743 		tidh_new->dest_se_deve = dest_se_deve;
1744 
1745 		/*
1746 		 * Allocate, but do NOT add the registration for the
1747 		 * TransportID referenced SCSI Initiator port.  This
1748 		 * done because of the following from spc4r17 in section
1749 		 * 6.14.3 wrt SPEC_I_PT:
1750 		 *
1751 		 * "If a registration fails for any initiator port (e.g., if th
1752 		 * logical unit does not have enough resources available to
1753 		 * hold the registration information), no registrations shall be
1754 		 * made, and the command shall be terminated with
1755 		 * CHECK CONDITION status."
1756 		 *
1757 		 * That means we call __core_scsi3_alloc_registration() here,
1758 		 * and then call __core_scsi3_add_registration() in the
1759 		 * 2nd loop which will never fail.
1760 		 */
1761 		dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
1762 				kref_read(&dest_se_deve->pr_kref) != 0);
1763 
1764 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1765 					dest_node_acl, dest_lun, dest_se_deve,
1766 					dest_se_deve->mapped_lun, iport_ptr,
1767 					sa_res_key, all_tg_pt, aptpl);
1768 		if (!dest_pr_reg) {
1769 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1770 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1771 			core_scsi3_tpg_undepend_item(dest_tpg);
1772 			kfree(tidh_new);
1773 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1774 			goto out_unmap;
1775 		}
1776 		tidh_new->dest_pr_reg = dest_pr_reg;
1777 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1778 
1779 		ptr += tid_len;
1780 		tpdl -= tid_len;
1781 		tid_len = 0;
1782 
1783 	}
1784 
1785 	transport_kunmap_data_sg(cmd);
1786 
1787 	/*
1788 	 * Go ahead and create a registrations from tid_dest_list for the
1789 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1790 	 * and dest_se_deve.
1791 	 *
1792 	 * The SA Reservation Key from the PROUT is set for the
1793 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1794 	 * means that the TransportID Initiator port will be
1795 	 * registered on all of the target ports in the SCSI target device
1796 	 * ALL_TG_PT=0 means the registration will only be for the
1797 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1798 	 * was received.
1799 	 */
1800 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1801 		dest_tpg = tidh->dest_tpg;
1802 		dest_node_acl = tidh->dest_node_acl;
1803 		dest_se_deve = tidh->dest_se_deve;
1804 		dest_pr_reg = tidh->dest_pr_reg;
1805 
1806 		list_del(&tidh->dest_list);
1807 		kfree(tidh);
1808 
1809 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1810 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1811 
1812 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1813 					dest_pr_reg, 0, 0);
1814 
1815 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1816 			" registered Transport ID for Node: %s%s Mapped LUN:"
1817 			" %llu\n", dest_tpg->se_tpg_tfo->fabric_name,
1818 			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
1819 			dest_se_deve->mapped_lun : 0);
1820 
1821 		if (!dest_se_deve) {
1822 			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1823 				 target_pr_kref_release);
1824 			continue;
1825 		}
1826 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1827 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1828 		core_scsi3_tpg_undepend_item(dest_tpg);
1829 	}
1830 
1831 	return 0;
1832 out_unmap:
1833 	transport_kunmap_data_sg(cmd);
1834 out:
1835 	/*
1836 	 * For the failure case, release everything from tid_dest_list
1837 	 * including *dest_pr_reg and the configfs dependances..
1838 	 */
1839 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1840 		dest_tpg = tidh->dest_tpg;
1841 		dest_node_acl = tidh->dest_node_acl;
1842 		dest_se_deve = tidh->dest_se_deve;
1843 		dest_pr_reg = tidh->dest_pr_reg;
1844 
1845 		list_del(&tidh->dest_list);
1846 		kfree(tidh);
1847 		/*
1848 		 * Release any extra ALL_TG_PT=1 registrations for
1849 		 * the SPEC_I_PT=1 case.
1850 		 */
1851 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1852 				&dest_pr_reg->pr_reg_atp_list,
1853 				pr_reg_atp_mem_list) {
1854 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1855 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1856 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1857 		}
1858 
1859 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1860 
1861 		if (!dest_se_deve) {
1862 			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1863 				 target_pr_kref_release);
1864 			continue;
1865 		}
1866 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1867 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1868 		core_scsi3_tpg_undepend_item(dest_tpg);
1869 	}
1870 	return ret;
1871 }
1872 
1873 static int core_scsi3_update_aptpl_buf(
1874 	struct se_device *dev,
1875 	unsigned char *buf,
1876 	u32 pr_aptpl_buf_len)
1877 {
1878 	struct se_portal_group *tpg;
1879 	struct t10_pr_registration *pr_reg;
1880 	unsigned char tmp[512], isid_buf[32];
1881 	ssize_t len = 0;
1882 	int reg_count = 0;
1883 	int ret = 0;
1884 
1885 	spin_lock(&dev->dev_reservation_lock);
1886 	spin_lock(&dev->t10_pr.registration_lock);
1887 	/*
1888 	 * Walk the registration list..
1889 	 */
1890 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1891 			pr_reg_list) {
1892 
1893 		tmp[0] = '\0';
1894 		isid_buf[0] = '\0';
1895 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1896 		/*
1897 		 * Write out any ISID value to APTPL metadata that was included
1898 		 * in the original registration.
1899 		 */
1900 		if (pr_reg->isid_present_at_reg)
1901 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1902 					pr_reg->pr_reg_isid);
1903 		/*
1904 		 * Include special metadata if the pr_reg matches the
1905 		 * reservation holder.
1906 		 */
1907 		if (dev->dev_pr_res_holder == pr_reg) {
1908 			snprintf(tmp, 512, "PR_REG_START: %d"
1909 				"\ninitiator_fabric=%s\n"
1910 				"initiator_node=%s\n%s"
1911 				"sa_res_key=%llu\n"
1912 				"res_holder=1\nres_type=%02x\n"
1913 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1914 				"mapped_lun=%llu\n", reg_count,
1915 				tpg->se_tpg_tfo->fabric_name,
1916 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1917 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1918 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1919 				pr_reg->pr_res_mapped_lun);
1920 		} else {
1921 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1922 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1923 				"sa_res_key=%llu\nres_holder=0\n"
1924 				"res_all_tg_pt=%d\nmapped_lun=%llu\n",
1925 				reg_count, tpg->se_tpg_tfo->fabric_name,
1926 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1927 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1928 				pr_reg->pr_res_mapped_lun);
1929 		}
1930 
1931 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1932 			pr_err("Unable to update renaming APTPL metadata,"
1933 			       " reallocating larger buffer\n");
1934 			ret = -EMSGSIZE;
1935 			goto out;
1936 		}
1937 		len += sprintf(buf+len, "%s", tmp);
1938 
1939 		/*
1940 		 * Include information about the associated SCSI target port.
1941 		 */
1942 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1943 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%llu\nPR_REG_END:"
1944 			" %d\n", tpg->se_tpg_tfo->fabric_name,
1945 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1946 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1947 			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
1948 			reg_count);
1949 
1950 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1951 			pr_err("Unable to update renaming APTPL metadata,"
1952 			       " reallocating larger buffer\n");
1953 			ret = -EMSGSIZE;
1954 			goto out;
1955 		}
1956 		len += sprintf(buf+len, "%s", tmp);
1957 		reg_count++;
1958 	}
1959 
1960 	if (!reg_count)
1961 		len += sprintf(buf+len, "No Registrations or Reservations");
1962 
1963 out:
1964 	spin_unlock(&dev->t10_pr.registration_lock);
1965 	spin_unlock(&dev->dev_reservation_lock);
1966 
1967 	return ret;
1968 }
1969 
1970 static int __core_scsi3_write_aptpl_to_file(
1971 	struct se_device *dev,
1972 	unsigned char *buf)
1973 {
1974 	struct t10_wwn *wwn = &dev->t10_wwn;
1975 	struct file *file;
1976 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1977 	char *path;
1978 	u32 pr_aptpl_buf_len;
1979 	int ret;
1980 	loff_t pos = 0;
1981 
1982 	path = kasprintf(GFP_KERNEL, "%s/pr/aptpl_%s", db_root,
1983 			&wwn->unit_serial[0]);
1984 	if (!path)
1985 		return -ENOMEM;
1986 
1987 	file = filp_open(path, flags, 0600);
1988 	if (IS_ERR(file)) {
1989 		pr_err("filp_open(%s) for APTPL metadata"
1990 			" failed\n", path);
1991 		kfree(path);
1992 		return PTR_ERR(file);
1993 	}
1994 
1995 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1996 
1997 	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);
1998 
1999 	if (ret < 0)
2000 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2001 	fput(file);
2002 	kfree(path);
2003 
2004 	return (ret < 0) ? -EIO : 0;
2005 }
2006 
2007 /*
2008  * Clear the APTPL metadata if APTPL has been disabled, otherwise
2009  * write out the updated metadata to struct file for this SCSI device.
2010  */
2011 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
2012 {
2013 	unsigned char *buf;
2014 	int rc, len = PR_APTPL_BUF_LEN;
2015 
2016 	if (!aptpl) {
2017 		char *null_buf = "No Registrations or Reservations\n";
2018 
2019 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
2020 		dev->t10_pr.pr_aptpl_active = 0;
2021 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
2022 
2023 		if (rc)
2024 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2025 
2026 		return 0;
2027 	}
2028 retry:
2029 	buf = vzalloc(len);
2030 	if (!buf)
2031 		return TCM_OUT_OF_RESOURCES;
2032 
2033 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
2034 	if (rc < 0) {
2035 		vfree(buf);
2036 		len *= 2;
2037 		goto retry;
2038 	}
2039 
2040 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2041 	if (rc != 0) {
2042 		pr_err("SPC-3 PR: Could not update APTPL\n");
2043 		vfree(buf);
2044 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2045 	}
2046 	dev->t10_pr.pr_aptpl_active = 1;
2047 	vfree(buf);
2048 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2049 	return 0;
2050 }
2051 
2052 static sense_reason_t
2053 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2054 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2055 {
2056 	struct se_session *se_sess = cmd->se_sess;
2057 	struct se_device *dev = cmd->se_dev;
2058 	struct se_lun *se_lun = cmd->se_lun;
2059 	struct se_portal_group *se_tpg;
2060 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2061 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2062 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2063 	sense_reason_t ret = TCM_NO_SENSE;
2064 	int pr_holder = 0, type;
2065 
2066 	if (!se_sess || !se_lun) {
2067 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2068 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2069 	}
2070 	se_tpg = se_sess->se_tpg;
2071 
2072 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2073 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2074 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2075 				PR_REG_ISID_LEN);
2076 		isid_ptr = &isid_buf[0];
2077 	}
2078 	/*
2079 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2080 	 */
2081 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2082 	if (!pr_reg) {
2083 		if (res_key) {
2084 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2085 				" for SA REGISTER, returning CONFLICT\n");
2086 			return TCM_RESERVATION_CONFLICT;
2087 		}
2088 		/*
2089 		 * Do nothing but return GOOD status.
2090 		 */
2091 		if (!sa_res_key)
2092 			return 0;
2093 
2094 		if (!spec_i_pt) {
2095 			/*
2096 			 * Perform the Service Action REGISTER on the Initiator
2097 			 * Port Endpoint that the PRO was received from on the
2098 			 * Logical Unit of the SCSI device server.
2099 			 */
2100 			if (core_scsi3_alloc_registration(cmd->se_dev,
2101 					se_sess->se_node_acl, cmd->se_lun,
2102 					NULL, cmd->orig_fe_lun, isid_ptr,
2103 					sa_res_key, all_tg_pt, aptpl,
2104 					register_type, 0)) {
2105 				pr_err("Unable to allocate"
2106 					" struct t10_pr_registration\n");
2107 				return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
2108 			}
2109 		} else {
2110 			/*
2111 			 * Register both the Initiator port that received
2112 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2113 			 * TransportID from Parameter list and loop through
2114 			 * fabric dependent parameter list while calling
2115 			 * logic from of core_scsi3_alloc_registration() for
2116 			 * each TransportID provided SCSI Initiator Port/Device
2117 			 */
2118 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2119 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2120 			if (ret != 0)
2121 				return ret;
2122 		}
2123 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2124 	}
2125 
2126 	/* ok, existing registration */
2127 
2128 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2129 		pr_err("SPC-3 PR REGISTER: Received"
2130 		       " res_key: 0x%016Lx does not match"
2131 		       " existing SA REGISTER res_key:"
2132 		       " 0x%016Lx\n", res_key,
2133 		       pr_reg->pr_res_key);
2134 		ret = TCM_RESERVATION_CONFLICT;
2135 		goto out;
2136 	}
2137 
2138 	if (spec_i_pt) {
2139 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2140 			" set on a registered nexus\n");
2141 		ret = TCM_INVALID_PARAMETER_LIST;
2142 		goto out;
2143 	}
2144 
2145 	/*
2146 	 * An existing ALL_TG_PT=1 registration being released
2147 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2148 	 */
2149 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2150 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2151 			" registration exists, but ALL_TG_PT=1 bit not"
2152 			" present in received PROUT\n");
2153 		ret = TCM_INVALID_CDB_FIELD;
2154 		goto out;
2155 	}
2156 
2157 	/*
2158 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2159 	 */
2160 	if (sa_res_key) {
2161 		/*
2162 		 * Increment PRgeneration counter for struct se_device"
2163 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2164 		 * READ_KEYS service action.
2165 		 */
2166 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2167 		pr_reg->pr_res_key = sa_res_key;
2168 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2169 			 " Key for %s to: 0x%016Lx PRgeneration:"
2170 			 " 0x%08x\n", cmd->se_tfo->fabric_name,
2171 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2172 			 pr_reg->pr_reg_nacl->initiatorname,
2173 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2174 
2175 	} else {
2176 		/*
2177 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2178 		 */
2179 		type = pr_reg->pr_res_type;
2180 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2181 							      pr_reg);
2182 		if (pr_holder < 0) {
2183 			ret = TCM_RESERVATION_CONFLICT;
2184 			goto out;
2185 		}
2186 
2187 		spin_lock(&pr_tmpl->registration_lock);
2188 		/*
2189 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2190 		 * and matching pr_res_key.
2191 		 */
2192 		if (pr_reg->pr_reg_all_tg_pt) {
2193 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2194 					&pr_tmpl->registration_list,
2195 					pr_reg_list) {
2196 
2197 				if (!pr_reg_p->pr_reg_all_tg_pt)
2198 					continue;
2199 				if (pr_reg_p->pr_res_key != res_key)
2200 					continue;
2201 				if (pr_reg == pr_reg_p)
2202 					continue;
2203 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2204 					   pr_reg_p->pr_reg_nacl->initiatorname))
2205 					continue;
2206 
2207 				__core_scsi3_free_registration(dev,
2208 						pr_reg_p, NULL, 0);
2209 			}
2210 		}
2211 
2212 		/*
2213 		 * Release the calling I_T Nexus registration now..
2214 		 */
2215 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2216 		pr_reg = NULL;
2217 
2218 		/*
2219 		 * From spc4r17, section 5.7.11.3 Unregistering
2220 		 *
2221 		 * If the persistent reservation is a registrants only
2222 		 * type, the device server shall establish a unit
2223 		 * attention condition for the initiator port associated
2224 		 * with every registered I_T nexus except for the I_T
2225 		 * nexus on which the PERSISTENT RESERVE OUT command was
2226 		 * received, with the additional sense code set to
2227 		 * RESERVATIONS RELEASED.
2228 		 */
2229 		if (pr_holder &&
2230 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2231 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2232 			list_for_each_entry(pr_reg_p,
2233 					&pr_tmpl->registration_list,
2234 					pr_reg_list) {
2235 
2236 				target_ua_allocate_lun(
2237 					pr_reg_p->pr_reg_nacl,
2238 					pr_reg_p->pr_res_mapped_lun,
2239 					0x2A,
2240 					ASCQ_2AH_RESERVATIONS_RELEASED);
2241 			}
2242 		}
2243 
2244 		spin_unlock(&pr_tmpl->registration_lock);
2245 	}
2246 
2247 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2248 
2249 out:
2250 	if (pr_reg)
2251 		core_scsi3_put_pr_reg(pr_reg);
2252 	return ret;
2253 }
2254 
2255 unsigned char *core_scsi3_pr_dump_type(int type)
2256 {
2257 	switch (type) {
2258 	case PR_TYPE_WRITE_EXCLUSIVE:
2259 		return "Write Exclusive Access";
2260 	case PR_TYPE_EXCLUSIVE_ACCESS:
2261 		return "Exclusive Access";
2262 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2263 		return "Write Exclusive Access, Registrants Only";
2264 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2265 		return "Exclusive Access, Registrants Only";
2266 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2267 		return "Write Exclusive Access, All Registrants";
2268 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2269 		return "Exclusive Access, All Registrants";
2270 	default:
2271 		break;
2272 	}
2273 
2274 	return "Unknown SPC-3 PR Type";
2275 }
2276 
2277 static sense_reason_t
2278 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2279 {
2280 	struct se_device *dev = cmd->se_dev;
2281 	struct se_session *se_sess = cmd->se_sess;
2282 	struct se_lun *se_lun = cmd->se_lun;
2283 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2284 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2285 	char i_buf[PR_REG_ISID_ID_LEN];
2286 	sense_reason_t ret;
2287 
2288 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2289 
2290 	if (!se_sess || !se_lun) {
2291 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2292 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2293 	}
2294 	/*
2295 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2296 	 */
2297 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2298 				se_sess);
2299 	if (!pr_reg) {
2300 		pr_err("SPC-3 PR: Unable to locate"
2301 			" PR_REGISTERED *pr_reg for RESERVE\n");
2302 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2303 	}
2304 	/*
2305 	 * From spc4r17 Section 5.7.9: Reserving:
2306 	 *
2307 	 * An application client creates a persistent reservation by issuing
2308 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2309 	 * a registered I_T nexus with the following parameters:
2310 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2311 	 * 	 registered with the logical unit for the I_T nexus; and
2312 	 */
2313 	if (res_key != pr_reg->pr_res_key) {
2314 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2315 			" does not match existing SA REGISTER res_key:"
2316 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2317 		ret = TCM_RESERVATION_CONFLICT;
2318 		goto out_put_pr_reg;
2319 	}
2320 	/*
2321 	 * From spc4r17 Section 5.7.9: Reserving:
2322 	 *
2323 	 * From above:
2324 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2325 	 *     being created.
2326 	 *
2327 	 * Only one persistent reservation is allowed at a time per logical unit
2328 	 * and that persistent reservation has a scope of LU_SCOPE.
2329 	 */
2330 	if (scope != PR_SCOPE_LU_SCOPE) {
2331 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2332 		ret = TCM_INVALID_PARAMETER_LIST;
2333 		goto out_put_pr_reg;
2334 	}
2335 	/*
2336 	 * See if we have an existing PR reservation holder pointer at
2337 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2338 	 * *pr_res_holder.
2339 	 */
2340 	spin_lock(&dev->dev_reservation_lock);
2341 	pr_res_holder = dev->dev_pr_res_holder;
2342 	if (pr_res_holder) {
2343 		/*
2344 		 * From spc4r17 Section 5.7.9: Reserving:
2345 		 *
2346 		 * If the device server receives a PERSISTENT RESERVE OUT
2347 		 * command from an I_T nexus other than a persistent reservation
2348 		 * holder (see 5.7.10) that attempts to create a persistent
2349 		 * reservation when a persistent reservation already exists for
2350 		 * the logical unit, then the command shall be completed with
2351 		 * RESERVATION CONFLICT status.
2352 		 */
2353 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2354 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2355 			pr_err("SPC-3 PR: Attempted RESERVE from"
2356 				" [%s]: %s while reservation already held by"
2357 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2358 				cmd->se_tfo->fabric_name,
2359 				se_sess->se_node_acl->initiatorname,
2360 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2361 				pr_res_holder->pr_reg_nacl->initiatorname);
2362 
2363 			spin_unlock(&dev->dev_reservation_lock);
2364 			ret = TCM_RESERVATION_CONFLICT;
2365 			goto out_put_pr_reg;
2366 		}
2367 		/*
2368 		 * From spc4r17 Section 5.7.9: Reserving:
2369 		 *
2370 		 * If a persistent reservation holder attempts to modify the
2371 		 * type or scope of an existing persistent reservation, the
2372 		 * command shall be completed with RESERVATION CONFLICT status.
2373 		 */
2374 		if ((pr_res_holder->pr_res_type != type) ||
2375 		    (pr_res_holder->pr_res_scope != scope)) {
2376 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2377 			pr_err("SPC-3 PR: Attempted RESERVE from"
2378 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2379 				" while reservation already held by [%s]: %s,"
2380 				" returning RESERVATION_CONFLICT\n",
2381 				cmd->se_tfo->fabric_name,
2382 				se_sess->se_node_acl->initiatorname,
2383 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2384 				pr_res_holder->pr_reg_nacl->initiatorname);
2385 
2386 			spin_unlock(&dev->dev_reservation_lock);
2387 			ret = TCM_RESERVATION_CONFLICT;
2388 			goto out_put_pr_reg;
2389 		}
2390 		/*
2391 		 * From spc4r17 Section 5.7.9: Reserving:
2392 		 *
2393 		 * If the device server receives a PERSISTENT RESERVE OUT
2394 		 * command with RESERVE service action where the TYPE field and
2395 		 * the SCOPE field contain the same values as the existing type
2396 		 * and scope from a persistent reservation holder, it shall not
2397 		 * make any change to the existing persistent reservation and
2398 		 * shall completethe command with GOOD status.
2399 		 */
2400 		spin_unlock(&dev->dev_reservation_lock);
2401 		ret = 0;
2402 		goto out_put_pr_reg;
2403 	}
2404 	/*
2405 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2406 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2407 	 */
2408 	pr_reg->pr_res_scope = scope;
2409 	pr_reg->pr_res_type = type;
2410 	pr_reg->pr_res_holder = 1;
2411 	dev->dev_pr_res_holder = pr_reg;
2412 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2413 
2414 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2415 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2416 		cmd->se_tfo->fabric_name, core_scsi3_pr_dump_type(type),
2417 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2418 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2419 			cmd->se_tfo->fabric_name,
2420 			se_sess->se_node_acl->initiatorname,
2421 			i_buf);
2422 	spin_unlock(&dev->dev_reservation_lock);
2423 
2424 	if (pr_tmpl->pr_aptpl_active)
2425 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2426 
2427 	ret = 0;
2428 out_put_pr_reg:
2429 	core_scsi3_put_pr_reg(pr_reg);
2430 	return ret;
2431 }
2432 
2433 static sense_reason_t
2434 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2435 		u64 res_key)
2436 {
2437 	switch (type) {
2438 	case PR_TYPE_WRITE_EXCLUSIVE:
2439 	case PR_TYPE_EXCLUSIVE_ACCESS:
2440 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2441 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2442 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2443 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2444 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2445 	default:
2446 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2447 			" 0x%02x\n", type);
2448 		return TCM_INVALID_CDB_FIELD;
2449 	}
2450 }
2451 
2452 static void __core_scsi3_complete_pro_release(
2453 	struct se_device *dev,
2454 	struct se_node_acl *se_nacl,
2455 	struct t10_pr_registration *pr_reg,
2456 	int explicit,
2457 	int unreg)
2458 {
2459 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2460 	char i_buf[PR_REG_ISID_ID_LEN];
2461 	int pr_res_type = 0, pr_res_scope = 0;
2462 
2463 	lockdep_assert_held(&dev->dev_reservation_lock);
2464 
2465 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2466 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2467 	/*
2468 	 * Go ahead and release the current PR reservation holder.
2469 	 * If an All Registrants reservation is currently active and
2470 	 * a unregister operation is requested, replace the current
2471 	 * dev_pr_res_holder with another active registration.
2472 	 */
2473 	if (dev->dev_pr_res_holder) {
2474 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2475 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2476 		dev->dev_pr_res_holder->pr_res_type = 0;
2477 		dev->dev_pr_res_holder->pr_res_scope = 0;
2478 		dev->dev_pr_res_holder->pr_res_holder = 0;
2479 		dev->dev_pr_res_holder = NULL;
2480 	}
2481 	if (!unreg)
2482 		goto out;
2483 
2484 	spin_lock(&dev->t10_pr.registration_lock);
2485 	list_del_init(&pr_reg->pr_reg_list);
2486 	/*
2487 	 * If the I_T nexus is a reservation holder, the persistent reservation
2488 	 * is of an all registrants type, and the I_T nexus is the last remaining
2489 	 * registered I_T nexus, then the device server shall also release the
2490 	 * persistent reservation.
2491 	 */
2492 	if (!list_empty(&dev->t10_pr.registration_list) &&
2493 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2494 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2495 		dev->dev_pr_res_holder =
2496 			list_entry(dev->t10_pr.registration_list.next,
2497 				   struct t10_pr_registration, pr_reg_list);
2498 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2499 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2500 		dev->dev_pr_res_holder->pr_res_holder = 1;
2501 	}
2502 	spin_unlock(&dev->t10_pr.registration_lock);
2503 out:
2504 	if (!dev->dev_pr_res_holder) {
2505 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2506 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2507 			tfo->fabric_name, (explicit) ? "explicit" :
2508 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2509 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2510 	}
2511 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2512 		tfo->fabric_name, se_nacl->initiatorname,
2513 		i_buf);
2514 	/*
2515 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2516 	 */
2517 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2518 }
2519 
2520 static sense_reason_t
2521 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2522 		u64 res_key)
2523 {
2524 	struct se_device *dev = cmd->se_dev;
2525 	struct se_session *se_sess = cmd->se_sess;
2526 	struct se_lun *se_lun = cmd->se_lun;
2527 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2528 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2529 	sense_reason_t ret = 0;
2530 
2531 	if (!se_sess || !se_lun) {
2532 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2533 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2534 	}
2535 	/*
2536 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2537 	 */
2538 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2539 	if (!pr_reg) {
2540 		pr_err("SPC-3 PR: Unable to locate"
2541 			" PR_REGISTERED *pr_reg for RELEASE\n");
2542 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2543 	}
2544 	/*
2545 	 * From spc4r17 Section 5.7.11.2 Releasing:
2546 	 *
2547 	 * If there is no persistent reservation or in response to a persistent
2548 	 * reservation release request from a registered I_T nexus that is not a
2549 	 * persistent reservation holder (see 5.7.10), the device server shall
2550 	 * do the following:
2551 	 *
2552 	 *     a) Not release the persistent reservation, if any;
2553 	 *     b) Not remove any registrations; and
2554 	 *     c) Complete the command with GOOD status.
2555 	 */
2556 	spin_lock(&dev->dev_reservation_lock);
2557 	pr_res_holder = dev->dev_pr_res_holder;
2558 	if (!pr_res_holder) {
2559 		/*
2560 		 * No persistent reservation, return GOOD status.
2561 		 */
2562 		spin_unlock(&dev->dev_reservation_lock);
2563 		goto out_put_pr_reg;
2564 	}
2565 
2566 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2567 		/*
2568 		 * Release request from a registered I_T nexus that is not a
2569 		 * persistent reservation holder. return GOOD status.
2570 		 */
2571 		spin_unlock(&dev->dev_reservation_lock);
2572 		goto out_put_pr_reg;
2573 	}
2574 
2575 	/*
2576 	 * From spc4r17 Section 5.7.11.2 Releasing:
2577 	 *
2578 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2579 	 * release a persistent reservation.
2580 	 *
2581 	 * An application client releases the persistent reservation by issuing
2582 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2583 	 * an I_T nexus that is a persistent reservation holder with the
2584 	 * following parameters:
2585 	 *
2586 	 *     a) RESERVATION KEY field set to the value of the reservation key
2587 	 *	  that is registered with the logical unit for the I_T nexus;
2588 	 */
2589 	if (res_key != pr_reg->pr_res_key) {
2590 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2591 			" does not match existing SA REGISTER res_key:"
2592 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2593 		spin_unlock(&dev->dev_reservation_lock);
2594 		ret = TCM_RESERVATION_CONFLICT;
2595 		goto out_put_pr_reg;
2596 	}
2597 	/*
2598 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2599 	 *
2600 	 * b) TYPE field and SCOPE field set to match the persistent
2601 	 *    reservation being released.
2602 	 */
2603 	if ((pr_res_holder->pr_res_type != type) ||
2604 	    (pr_res_holder->pr_res_scope != scope)) {
2605 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2606 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2607 			" reservation from [%s]: %s with different TYPE "
2608 			"and/or SCOPE  while reservation already held by"
2609 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2610 			cmd->se_tfo->fabric_name,
2611 			se_sess->se_node_acl->initiatorname,
2612 			pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2613 			pr_res_holder->pr_reg_nacl->initiatorname);
2614 
2615 		spin_unlock(&dev->dev_reservation_lock);
2616 		ret = TCM_RESERVATION_CONFLICT;
2617 		goto out_put_pr_reg;
2618 	}
2619 	/*
2620 	 * In response to a persistent reservation release request from the
2621 	 * persistent reservation holder the device server shall perform a
2622 	 * release by doing the following as an uninterrupted series of actions:
2623 	 * a) Release the persistent reservation;
2624 	 * b) Not remove any registration(s);
2625 	 * c) If the released persistent reservation is a registrants only type
2626 	 * or all registrants type persistent reservation,
2627 	 *    the device server shall establish a unit attention condition for
2628 	 *    the initiator port associated with every regis-
2629 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2630 	 *    RESERVE OUT command with RELEASE service action was received,
2631 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2632 	 * d) If the persistent reservation is of any other type, the device
2633 	 *    server shall not establish a unit attention condition.
2634 	 */
2635 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2636 					  pr_reg, 1, 0);
2637 
2638 	spin_unlock(&dev->dev_reservation_lock);
2639 
2640 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2641 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2642 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2643 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2644 		/*
2645 		 * If no UNIT ATTENTION conditions will be established for
2646 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2647 		 * go ahead and check for APTPL=1 update+write below
2648 		 */
2649 		goto write_aptpl;
2650 	}
2651 
2652 	spin_lock(&pr_tmpl->registration_lock);
2653 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2654 			pr_reg_list) {
2655 		/*
2656 		 * Do not establish a UNIT ATTENTION condition
2657 		 * for the calling I_T Nexus
2658 		 */
2659 		if (pr_reg_p == pr_reg)
2660 			continue;
2661 
2662 		target_ua_allocate_lun(pr_reg_p->pr_reg_nacl,
2663 				pr_reg_p->pr_res_mapped_lun,
2664 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2665 	}
2666 	spin_unlock(&pr_tmpl->registration_lock);
2667 
2668 write_aptpl:
2669 	if (pr_tmpl->pr_aptpl_active)
2670 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2671 
2672 out_put_pr_reg:
2673 	core_scsi3_put_pr_reg(pr_reg);
2674 	return ret;
2675 }
2676 
2677 static sense_reason_t
2678 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2679 {
2680 	struct se_device *dev = cmd->se_dev;
2681 	struct se_node_acl *pr_reg_nacl;
2682 	struct se_session *se_sess = cmd->se_sess;
2683 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2684 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2685 	u64 pr_res_mapped_lun = 0;
2686 	int calling_it_nexus = 0;
2687 	/*
2688 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2689 	 */
2690 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2691 			se_sess->se_node_acl, se_sess);
2692 	if (!pr_reg_n) {
2693 		pr_err("SPC-3 PR: Unable to locate"
2694 			" PR_REGISTERED *pr_reg for CLEAR\n");
2695 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2696 	}
2697 	/*
2698 	 * From spc4r17 section 5.7.11.6, Clearing:
2699 	 *
2700 	 * Any application client may release the persistent reservation and
2701 	 * remove all registrations from a device server by issuing a
2702 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2703 	 * registered I_T nexus with the following parameter:
2704 	 *
2705 	 *	a) RESERVATION KEY field set to the value of the reservation key
2706 	 * 	   that is registered with the logical unit for the I_T nexus.
2707 	 */
2708 	if (res_key != pr_reg_n->pr_res_key) {
2709 		pr_err("SPC-3 PR REGISTER: Received"
2710 			" res_key: 0x%016Lx does not match"
2711 			" existing SA REGISTER res_key:"
2712 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2713 		core_scsi3_put_pr_reg(pr_reg_n);
2714 		return TCM_RESERVATION_CONFLICT;
2715 	}
2716 	/*
2717 	 * a) Release the persistent reservation, if any;
2718 	 */
2719 	spin_lock(&dev->dev_reservation_lock);
2720 	pr_res_holder = dev->dev_pr_res_holder;
2721 	if (pr_res_holder) {
2722 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2723 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2724 						  pr_res_holder, 0, 0);
2725 	}
2726 	spin_unlock(&dev->dev_reservation_lock);
2727 	/*
2728 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2729 	 */
2730 	spin_lock(&pr_tmpl->registration_lock);
2731 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2732 			&pr_tmpl->registration_list, pr_reg_list) {
2733 
2734 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2735 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2736 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2737 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2738 					calling_it_nexus);
2739 		/*
2740 		 * e) Establish a unit attention condition for the initiator
2741 		 *    port associated with every registered I_T nexus other
2742 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2743 		 *    command with CLEAR service action was received, with the
2744 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2745 		 */
2746 		if (!calling_it_nexus)
2747 			target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun,
2748 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2749 	}
2750 	spin_unlock(&pr_tmpl->registration_lock);
2751 
2752 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2753 		cmd->se_tfo->fabric_name);
2754 
2755 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2756 
2757 	core_scsi3_pr_generation(dev);
2758 	return 0;
2759 }
2760 
2761 static void __core_scsi3_complete_pro_preempt(
2762 	struct se_device *dev,
2763 	struct t10_pr_registration *pr_reg,
2764 	struct list_head *preempt_and_abort_list,
2765 	int type,
2766 	int scope,
2767 	enum preempt_type preempt_type)
2768 {
2769 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2770 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2771 	char i_buf[PR_REG_ISID_ID_LEN];
2772 
2773 	lockdep_assert_held(&dev->dev_reservation_lock);
2774 
2775 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2776 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2777 	/*
2778 	 * Do an implicit RELEASE of the existing reservation.
2779 	 */
2780 	if (dev->dev_pr_res_holder)
2781 		__core_scsi3_complete_pro_release(dev, nacl,
2782 						  dev->dev_pr_res_holder, 0, 0);
2783 
2784 	dev->dev_pr_res_holder = pr_reg;
2785 	pr_reg->pr_res_holder = 1;
2786 	pr_reg->pr_res_type = type;
2787 	pr_reg->pr_res_scope = scope;
2788 
2789 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2790 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2791 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2792 		core_scsi3_pr_dump_type(type),
2793 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2794 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2795 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2796 		nacl->initiatorname, i_buf);
2797 	/*
2798 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2799 	 * struct t10_pr_registration to the list that will be compared
2800 	 * against received CDBs..
2801 	 */
2802 	if (preempt_and_abort_list)
2803 		list_add_tail(&pr_reg->pr_reg_abort_list,
2804 				preempt_and_abort_list);
2805 }
2806 
2807 static void core_scsi3_release_preempt_and_abort(
2808 	struct list_head *preempt_and_abort_list,
2809 	struct t10_pr_registration *pr_reg_holder)
2810 {
2811 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2812 
2813 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2814 				pr_reg_abort_list) {
2815 
2816 		list_del(&pr_reg->pr_reg_abort_list);
2817 		if (pr_reg_holder == pr_reg)
2818 			continue;
2819 		if (pr_reg->pr_res_holder) {
2820 			pr_warn("pr_reg->pr_res_holder still set\n");
2821 			continue;
2822 		}
2823 
2824 		pr_reg->pr_reg_deve = NULL;
2825 		pr_reg->pr_reg_nacl = NULL;
2826 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2827 	}
2828 }
2829 
2830 static sense_reason_t
2831 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2832 		u64 sa_res_key, enum preempt_type preempt_type)
2833 {
2834 	struct se_device *dev = cmd->se_dev;
2835 	struct se_node_acl *pr_reg_nacl;
2836 	struct se_session *se_sess = cmd->se_sess;
2837 	LIST_HEAD(preempt_and_abort_list);
2838 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2839 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2840 	u64 pr_res_mapped_lun = 0;
2841 	int all_reg = 0, calling_it_nexus = 0;
2842 	bool sa_res_key_unmatched = sa_res_key != 0;
2843 	int prh_type = 0, prh_scope = 0;
2844 
2845 	if (!se_sess)
2846 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2847 
2848 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2849 				se_sess);
2850 	if (!pr_reg_n) {
2851 		pr_err("SPC-3 PR: Unable to locate"
2852 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2853 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2854 		return TCM_RESERVATION_CONFLICT;
2855 	}
2856 	if (pr_reg_n->pr_res_key != res_key) {
2857 		core_scsi3_put_pr_reg(pr_reg_n);
2858 		return TCM_RESERVATION_CONFLICT;
2859 	}
2860 	if (scope != PR_SCOPE_LU_SCOPE) {
2861 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2862 		core_scsi3_put_pr_reg(pr_reg_n);
2863 		return TCM_INVALID_PARAMETER_LIST;
2864 	}
2865 
2866 	spin_lock(&dev->dev_reservation_lock);
2867 	pr_res_holder = dev->dev_pr_res_holder;
2868 	if (pr_res_holder &&
2869 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2870 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2871 		all_reg = 1;
2872 
2873 	if (!all_reg && !sa_res_key) {
2874 		spin_unlock(&dev->dev_reservation_lock);
2875 		core_scsi3_put_pr_reg(pr_reg_n);
2876 		return TCM_INVALID_PARAMETER_LIST;
2877 	}
2878 	/*
2879 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2880 	 *
2881 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2882 	 * persistent reservation holder or there is no persistent reservation
2883 	 * holder (i.e., there is no persistent reservation), then the device
2884 	 * server shall perform a preempt by doing the following in an
2885 	 * uninterrupted series of actions. (See below..)
2886 	 */
2887 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2888 		/*
2889 		 * No existing or SA Reservation Key matching reservations..
2890 		 *
2891 		 * PROUT SA PREEMPT with All Registrant type reservations are
2892 		 * allowed to be processed without a matching SA Reservation Key
2893 		 */
2894 		spin_lock(&pr_tmpl->registration_lock);
2895 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2896 				&pr_tmpl->registration_list, pr_reg_list) {
2897 			/*
2898 			 * Removing of registrations in non all registrants
2899 			 * type reservations without a matching SA reservation
2900 			 * key.
2901 			 *
2902 			 * a) Remove the registrations for all I_T nexuses
2903 			 *    specified by the SERVICE ACTION RESERVATION KEY
2904 			 *    field;
2905 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2906 			 * c) Process tasks as defined in 5.7.1; and
2907 			 * d) Establish a unit attention condition for the
2908 			 *    initiator port associated with every I_T nexus
2909 			 *    that lost its registration other than the I_T
2910 			 *    nexus on which the PERSISTENT RESERVE OUT command
2911 			 *    was received, with the additional sense code set
2912 			 *    to REGISTRATIONS PREEMPTED.
2913 			 */
2914 			if (!all_reg) {
2915 				if (pr_reg->pr_res_key != sa_res_key)
2916 					continue;
2917 				sa_res_key_unmatched = false;
2918 
2919 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2920 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2921 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2922 				__core_scsi3_free_registration(dev, pr_reg,
2923 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2924 						NULL, calling_it_nexus);
2925 			} else {
2926 				/*
2927 				 * Case for any existing all registrants type
2928 				 * reservation, follow logic in spc4r17 section
2929 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2930 				 *
2931 				 * For a ZERO SA Reservation key, release
2932 				 * all other registrations and do an implicit
2933 				 * release of active persistent reservation.
2934 				 *
2935 				 * For a non-ZERO SA Reservation key, only
2936 				 * release the matching reservation key from
2937 				 * registrations.
2938 				 */
2939 				if ((sa_res_key) &&
2940 				     (pr_reg->pr_res_key != sa_res_key))
2941 					continue;
2942 				sa_res_key_unmatched = false;
2943 
2944 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2945 				if (calling_it_nexus)
2946 					continue;
2947 
2948 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2949 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2950 				__core_scsi3_free_registration(dev, pr_reg,
2951 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2952 						NULL, 0);
2953 			}
2954 			if (!calling_it_nexus)
2955 				target_ua_allocate_lun(pr_reg_nacl,
2956 					pr_res_mapped_lun, 0x2A,
2957 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2958 		}
2959 		spin_unlock(&pr_tmpl->registration_lock);
2960 		/*
2961 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2962 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2963 		 * RESERVATION KEY field to a value that does not match any
2964 		 * registered reservation key, then the device server shall
2965 		 * complete the command with RESERVATION CONFLICT status.
2966 		 */
2967 		if (sa_res_key_unmatched) {
2968 			spin_unlock(&dev->dev_reservation_lock);
2969 			core_scsi3_put_pr_reg(pr_reg_n);
2970 			return TCM_RESERVATION_CONFLICT;
2971 		}
2972 		/*
2973 		 * For an existing all registrants type reservation
2974 		 * with a zero SA rservation key, preempt the existing
2975 		 * reservation with the new PR type and scope.
2976 		 */
2977 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2978 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2979 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2980 				type, scope, preempt_type);
2981 
2982 			if (preempt_type == PREEMPT_AND_ABORT)
2983 				core_scsi3_release_preempt_and_abort(
2984 					&preempt_and_abort_list, pr_reg_n);
2985 		}
2986 		spin_unlock(&dev->dev_reservation_lock);
2987 
2988 		if (pr_tmpl->pr_aptpl_active)
2989 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2990 
2991 		core_scsi3_put_pr_reg(pr_reg_n);
2992 		core_scsi3_pr_generation(cmd->se_dev);
2993 		return 0;
2994 	}
2995 	/*
2996 	 * The PREEMPTing SA reservation key matches that of the
2997 	 * existing persistent reservation, first, we check if
2998 	 * we are preempting our own reservation.
2999 	 * From spc4r17, section 5.7.11.4.3 Preempting
3000 	 * persistent reservations and registration handling
3001 	 *
3002 	 * If an all registrants persistent reservation is not
3003 	 * present, it is not an error for the persistent
3004 	 * reservation holder to preempt itself (i.e., a
3005 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3006 	 * or a PREEMPT AND ABORT service action with the
3007 	 * SERVICE ACTION RESERVATION KEY value equal to the
3008 	 * persistent reservation holder's reservation key that
3009 	 * is received from the persistent reservation holder).
3010 	 * In that case, the device server shall establish the
3011 	 * new persistent reservation and maintain the
3012 	 * registration.
3013 	 */
3014 	prh_type = pr_res_holder->pr_res_type;
3015 	prh_scope = pr_res_holder->pr_res_scope;
3016 	/*
3017 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3018 	 * persistent reservation holder (see 5.7.10), the device
3019 	 * server shall perform a preempt by doing the following as
3020 	 * an uninterrupted series of actions:
3021 	 *
3022 	 * a) Release the persistent reservation for the holder
3023 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3024 	 */
3025 	if (pr_reg_n != pr_res_holder)
3026 		__core_scsi3_complete_pro_release(dev,
3027 						  pr_res_holder->pr_reg_nacl,
3028 						  dev->dev_pr_res_holder, 0, 0);
3029 	/*
3030 	 * b) Remove the registrations for all I_T nexuses identified
3031 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3032 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3033 	 *    OUT command. If an all registrants persistent reservation
3034 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3035 	 *    is set to zero, then all registrations shall be removed
3036 	 *    except for that of the I_T nexus that is being used for
3037 	 *    the PERSISTENT RESERVE OUT command;
3038 	 */
3039 	spin_lock(&pr_tmpl->registration_lock);
3040 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3041 			&pr_tmpl->registration_list, pr_reg_list) {
3042 
3043 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3044 		if (calling_it_nexus)
3045 			continue;
3046 
3047 		if (pr_reg->pr_res_key != sa_res_key)
3048 			continue;
3049 
3050 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3051 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3052 		__core_scsi3_free_registration(dev, pr_reg,
3053 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3054 				calling_it_nexus);
3055 		/*
3056 		 * e) Establish a unit attention condition for the initiator
3057 		 *    port associated with every I_T nexus that lost its
3058 		 *    persistent reservation and/or registration, with the
3059 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3060 		 */
3061 		target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3062 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3063 	}
3064 	spin_unlock(&pr_tmpl->registration_lock);
3065 	/*
3066 	 * c) Establish a persistent reservation for the preempting
3067 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3068 	 */
3069 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3070 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3071 			type, scope, preempt_type);
3072 	/*
3073 	 * d) Process tasks as defined in 5.7.1;
3074 	 * e) See above..
3075 	 * f) If the type or scope has changed, then for every I_T nexus
3076 	 *    whose reservation key was not removed, except for the I_T
3077 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3078 	 *    received, the device server shall establish a unit
3079 	 *    attention condition for the initiator port associated with
3080 	 *    that I_T nexus, with the additional sense code set to
3081 	 *    RESERVATIONS RELEASED. If the type or scope have not
3082 	 *    changed, then no unit attention condition(s) shall be
3083 	 *    established for this reason.
3084 	 */
3085 	if ((prh_type != type) || (prh_scope != scope)) {
3086 		spin_lock(&pr_tmpl->registration_lock);
3087 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3088 				&pr_tmpl->registration_list, pr_reg_list) {
3089 
3090 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3091 			if (calling_it_nexus)
3092 				continue;
3093 
3094 			target_ua_allocate_lun(pr_reg->pr_reg_nacl,
3095 					pr_reg->pr_res_mapped_lun, 0x2A,
3096 					ASCQ_2AH_RESERVATIONS_RELEASED);
3097 		}
3098 		spin_unlock(&pr_tmpl->registration_lock);
3099 	}
3100 	spin_unlock(&dev->dev_reservation_lock);
3101 	/*
3102 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3103 	 * All received CDBs for the matching existing reservation and
3104 	 * registrations undergo ABORT_TASK logic.
3105 	 *
3106 	 * From there, core_scsi3_release_preempt_and_abort() will
3107 	 * release every registration in the list (which have already
3108 	 * been removed from the primary pr_reg list), except the
3109 	 * new persistent reservation holder, the calling Initiator Port.
3110 	 */
3111 	if (preempt_type == PREEMPT_AND_ABORT) {
3112 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3113 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3114 						pr_reg_n);
3115 	}
3116 
3117 	if (pr_tmpl->pr_aptpl_active)
3118 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3119 
3120 	core_scsi3_put_pr_reg(pr_reg_n);
3121 	core_scsi3_pr_generation(cmd->se_dev);
3122 	return 0;
3123 }
3124 
3125 static sense_reason_t
3126 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3127 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3128 {
3129 	switch (type) {
3130 	case PR_TYPE_WRITE_EXCLUSIVE:
3131 	case PR_TYPE_EXCLUSIVE_ACCESS:
3132 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3133 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3134 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3135 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3136 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3137 					      sa_res_key, preempt_type);
3138 	default:
3139 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3140 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3141 		return TCM_INVALID_CDB_FIELD;
3142 	}
3143 }
3144 
3145 
3146 static sense_reason_t
3147 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3148 		u64 sa_res_key, int aptpl, int unreg)
3149 {
3150 	struct se_session *se_sess = cmd->se_sess;
3151 	struct se_device *dev = cmd->se_dev;
3152 	struct se_dev_entry *dest_se_deve = NULL;
3153 	struct se_lun *se_lun = cmd->se_lun, *tmp_lun;
3154 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3155 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3156 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3157 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3158 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3159 	unsigned char *buf;
3160 	const unsigned char *initiator_str;
3161 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
3162 	u32 tid_len, tmp_tid_len;
3163 	int new_reg = 0, type, scope, matching_iname;
3164 	sense_reason_t ret;
3165 	unsigned short rtpi;
3166 	unsigned char proto_ident;
3167 
3168 	if (!se_sess || !se_lun) {
3169 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3170 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3171 	}
3172 
3173 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3174 	se_tpg = se_sess->se_tpg;
3175 	tf_ops = se_tpg->se_tpg_tfo;
3176 	/*
3177 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3178 	 *	Register behaviors for a REGISTER AND MOVE service action
3179 	 *
3180 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3181 	 */
3182 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3183 				se_sess);
3184 	if (!pr_reg) {
3185 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3186 			" *pr_reg for REGISTER_AND_MOVE\n");
3187 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3188 	}
3189 	/*
3190 	 * The provided reservation key much match the existing reservation key
3191 	 * provided during this initiator's I_T nexus registration.
3192 	 */
3193 	if (res_key != pr_reg->pr_res_key) {
3194 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3195 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3196 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3197 		ret = TCM_RESERVATION_CONFLICT;
3198 		goto out_put_pr_reg;
3199 	}
3200 	/*
3201 	 * The service active reservation key needs to be non zero
3202 	 */
3203 	if (!sa_res_key) {
3204 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3205 			" sa_res_key\n");
3206 		ret = TCM_INVALID_PARAMETER_LIST;
3207 		goto out_put_pr_reg;
3208 	}
3209 
3210 	/*
3211 	 * Determine the Relative Target Port Identifier where the reservation
3212 	 * will be moved to for the TransportID containing SCSI initiator WWN
3213 	 * information.
3214 	 */
3215 	buf = transport_kmap_data_sg(cmd);
3216 	if (!buf) {
3217 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3218 		goto out_put_pr_reg;
3219 	}
3220 
3221 	rtpi = get_unaligned_be16(&buf[18]);
3222 	tid_len = get_unaligned_be32(&buf[20]);
3223 	transport_kunmap_data_sg(cmd);
3224 	buf = NULL;
3225 
3226 	if ((tid_len + 24) != cmd->data_length) {
3227 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3228 			" does not equal CDB data_length: %u\n", tid_len,
3229 			cmd->data_length);
3230 		ret = TCM_INVALID_PARAMETER_LIST;
3231 		goto out_put_pr_reg;
3232 	}
3233 
3234 	spin_lock(&dev->se_port_lock);
3235 	list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
3236 		if (tmp_lun->lun_rtpi != rtpi)
3237 			continue;
3238 		dest_se_tpg = tmp_lun->lun_tpg;
3239 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3240 		if (!dest_tf_ops)
3241 			continue;
3242 
3243 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3244 		spin_unlock(&dev->se_port_lock);
3245 
3246 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3247 			pr_err("core_scsi3_tpg_depend_item() failed"
3248 				" for dest_se_tpg\n");
3249 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3250 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3251 			goto out_put_pr_reg;
3252 		}
3253 
3254 		spin_lock(&dev->se_port_lock);
3255 		break;
3256 	}
3257 	spin_unlock(&dev->se_port_lock);
3258 
3259 	if (!dest_se_tpg || !dest_tf_ops) {
3260 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3261 			" fabric ops from Relative Target Port Identifier:"
3262 			" %hu\n", rtpi);
3263 		ret = TCM_INVALID_PARAMETER_LIST;
3264 		goto out_put_pr_reg;
3265 	}
3266 
3267 	buf = transport_kmap_data_sg(cmd);
3268 	if (!buf) {
3269 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3270 		goto out_put_pr_reg;
3271 	}
3272 	proto_ident = (buf[24] & 0x0f);
3273 
3274 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3275 			" 0x%02x\n", proto_ident);
3276 
3277 	if (proto_ident != dest_se_tpg->proto_id) {
3278 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3279 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3280 			" from fabric: %s\n", proto_ident,
3281 			dest_se_tpg->proto_id,
3282 			dest_tf_ops->fabric_name);
3283 		ret = TCM_INVALID_PARAMETER_LIST;
3284 		goto out;
3285 	}
3286 	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
3287 			&buf[24], &tmp_tid_len, &iport_ptr);
3288 	if (!initiator_str) {
3289 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3290 			" initiator_str from Transport ID\n");
3291 		ret = TCM_INVALID_PARAMETER_LIST;
3292 		goto out;
3293 	}
3294 
3295 	transport_kunmap_data_sg(cmd);
3296 	buf = NULL;
3297 
3298 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3299 		" %s\n", dest_tf_ops->fabric_name, (iport_ptr != NULL) ?
3300 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3301 		iport_ptr : "");
3302 	/*
3303 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3304 	 * action specifies a TransportID that is the same as the initiator port
3305 	 * of the I_T nexus for the command received, then the command shall
3306 	 * be terminated with CHECK CONDITION status, with the sense key set to
3307 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3308 	 * IN PARAMETER LIST.
3309 	 */
3310 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3311 	matching_iname = (!strcmp(initiator_str,
3312 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3313 	if (!matching_iname)
3314 		goto after_iport_check;
3315 
3316 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3317 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3318 			" matches: %s on received I_T Nexus\n", initiator_str,
3319 			pr_reg_nacl->initiatorname);
3320 		ret = TCM_INVALID_PARAMETER_LIST;
3321 		goto out;
3322 	}
3323 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3324 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3325 			" matches: %s %s on received I_T Nexus\n",
3326 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3327 			pr_reg->pr_reg_isid);
3328 		ret = TCM_INVALID_PARAMETER_LIST;
3329 		goto out;
3330 	}
3331 after_iport_check:
3332 	/*
3333 	 * Locate the destination struct se_node_acl from the received Transport ID
3334 	 */
3335 	mutex_lock(&dest_se_tpg->acl_node_mutex);
3336 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3337 				initiator_str);
3338 	if (dest_node_acl)
3339 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3340 	mutex_unlock(&dest_se_tpg->acl_node_mutex);
3341 
3342 	if (!dest_node_acl) {
3343 		pr_err("Unable to locate %s dest_node_acl for"
3344 			" TransportID%s\n", dest_tf_ops->fabric_name,
3345 			initiator_str);
3346 		ret = TCM_INVALID_PARAMETER_LIST;
3347 		goto out;
3348 	}
3349 
3350 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3351 		pr_err("core_scsi3_nodeacl_depend_item() for"
3352 			" dest_node_acl\n");
3353 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3354 		dest_node_acl = NULL;
3355 		ret = TCM_INVALID_PARAMETER_LIST;
3356 		goto out;
3357 	}
3358 
3359 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3360 		" %s from TransportID\n", dest_tf_ops->fabric_name,
3361 		dest_node_acl->initiatorname);
3362 
3363 	/*
3364 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3365 	 * PORT IDENTIFIER.
3366 	 */
3367 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3368 	if (!dest_se_deve) {
3369 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3370 			" %hu\n",  dest_tf_ops->fabric_name, rtpi);
3371 		ret = TCM_INVALID_PARAMETER_LIST;
3372 		goto out;
3373 	}
3374 
3375 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3376 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3377 		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
3378 		dest_se_deve = NULL;
3379 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3380 		goto out;
3381 	}
3382 
3383 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3384 		" ACL for dest_se_deve->mapped_lun: %llu\n",
3385 		dest_tf_ops->fabric_name, dest_node_acl->initiatorname,
3386 		dest_se_deve->mapped_lun);
3387 
3388 	/*
3389 	 * A persistent reservation needs to already existing in order to
3390 	 * successfully complete the REGISTER_AND_MOVE service action..
3391 	 */
3392 	spin_lock(&dev->dev_reservation_lock);
3393 	pr_res_holder = dev->dev_pr_res_holder;
3394 	if (!pr_res_holder) {
3395 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3396 			" currently held\n");
3397 		spin_unlock(&dev->dev_reservation_lock);
3398 		ret = TCM_INVALID_CDB_FIELD;
3399 		goto out;
3400 	}
3401 	/*
3402 	 * The received on I_T Nexus must be the reservation holder.
3403 	 *
3404 	 * From spc4r17 section 5.7.8  Table 50 --
3405 	 * 	Register behaviors for a REGISTER AND MOVE service action
3406 	 */
3407 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3408 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3409 			" Nexus is not reservation holder\n");
3410 		spin_unlock(&dev->dev_reservation_lock);
3411 		ret = TCM_RESERVATION_CONFLICT;
3412 		goto out;
3413 	}
3414 	/*
3415 	 * From spc4r17 section 5.7.8: registering and moving reservation
3416 	 *
3417 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3418 	 * action is received and the established persistent reservation is a
3419 	 * Write Exclusive - All Registrants type or Exclusive Access -
3420 	 * All Registrants type reservation, then the command shall be completed
3421 	 * with RESERVATION CONFLICT status.
3422 	 */
3423 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3424 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3425 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3426 			" reservation for type: %s\n",
3427 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3428 		spin_unlock(&dev->dev_reservation_lock);
3429 		ret = TCM_RESERVATION_CONFLICT;
3430 		goto out;
3431 	}
3432 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3433 	/*
3434 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3435 	 */
3436 	type = pr_res_holder->pr_res_type;
3437 	scope = pr_res_holder->pr_res_type;
3438 	/*
3439 	 * c) Associate the reservation key specified in the SERVICE ACTION
3440 	 *    RESERVATION KEY field with the I_T nexus specified as the
3441 	 *    destination of the register and move, where:
3442 	 *    A) The I_T nexus is specified by the TransportID and the
3443 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3444 	 *    B) Regardless of the TransportID format used, the association for
3445 	 *       the initiator port is based on either the initiator port name
3446 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3447 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3448 	 *       transport protocols where port names are not required;
3449 	 * d) Register the reservation key specified in the SERVICE ACTION
3450 	 *    RESERVATION KEY field;
3451 	 * e) Retain the reservation key specified in the SERVICE ACTION
3452 	 *    RESERVATION KEY field and associated information;
3453 	 *
3454 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3455 	 * register an I_T nexus that is already registered with the same
3456 	 * reservation key or a different reservation key.
3457 	 */
3458 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3459 					iport_ptr);
3460 	if (!dest_pr_reg) {
3461 		struct se_lun *dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
3462 				kref_read(&dest_se_deve->pr_kref) != 0);
3463 
3464 		spin_unlock(&dev->dev_reservation_lock);
3465 		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
3466 					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
3467 					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
3468 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3469 			goto out;
3470 		}
3471 		spin_lock(&dev->dev_reservation_lock);
3472 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3473 						iport_ptr);
3474 		new_reg = 1;
3475 	}
3476 	/*
3477 	 * f) Release the persistent reservation for the persistent reservation
3478 	 *    holder (i.e., the I_T nexus on which the
3479 	 */
3480 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3481 					  dev->dev_pr_res_holder, 0, 0);
3482 	/*
3483 	 * g) Move the persistent reservation to the specified I_T nexus using
3484 	 *    the same scope and type as the persistent reservation released in
3485 	 *    item f); and
3486 	 */
3487 	dev->dev_pr_res_holder = dest_pr_reg;
3488 	dest_pr_reg->pr_res_holder = 1;
3489 	dest_pr_reg->pr_res_type = type;
3490 	pr_reg->pr_res_scope = scope;
3491 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3492 	/*
3493 	 * Increment PRGeneration for existing registrations..
3494 	 */
3495 	if (!new_reg)
3496 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3497 	spin_unlock(&dev->dev_reservation_lock);
3498 
3499 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3500 		" created new reservation holder TYPE: %s on object RTPI:"
3501 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->fabric_name,
3502 		core_scsi3_pr_dump_type(type), rtpi,
3503 		dest_pr_reg->pr_res_generation);
3504 	pr_debug("SPC-3 PR Successfully moved reservation from"
3505 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3506 		tf_ops->fabric_name, pr_reg_nacl->initiatorname,
3507 		i_buf, dest_tf_ops->fabric_name,
3508 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3509 		iport_ptr : "");
3510 	/*
3511 	 * It is now safe to release configfs group dependencies for destination
3512 	 * of Transport ID Initiator Device/Port Identifier
3513 	 */
3514 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3515 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3516 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3517 	/*
3518 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3519 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3520 	 */
3521 	if (unreg) {
3522 		spin_lock(&pr_tmpl->registration_lock);
3523 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3524 		spin_unlock(&pr_tmpl->registration_lock);
3525 	} else
3526 		core_scsi3_put_pr_reg(pr_reg);
3527 
3528 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3529 
3530 	core_scsi3_put_pr_reg(dest_pr_reg);
3531 	return 0;
3532 out:
3533 	if (buf)
3534 		transport_kunmap_data_sg(cmd);
3535 	if (dest_se_deve)
3536 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3537 	if (dest_node_acl)
3538 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3539 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3540 
3541 out_put_pr_reg:
3542 	core_scsi3_put_pr_reg(pr_reg);
3543 	return ret;
3544 }
3545 
3546 /*
3547  * See spc4r17 section 6.14 Table 170
3548  */
3549 sense_reason_t
3550 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3551 {
3552 	struct se_device *dev = cmd->se_dev;
3553 	unsigned char *cdb = &cmd->t_task_cdb[0];
3554 	unsigned char *buf;
3555 	u64 res_key, sa_res_key;
3556 	int sa, scope, type, aptpl;
3557 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3558 	sense_reason_t ret;
3559 
3560 	/*
3561 	 * Following spc2r20 5.5.1 Reservations overview:
3562 	 *
3563 	 * If a logical unit has been reserved by any RESERVE command and is
3564 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3565 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3566 	 * initiator or service action and shall terminate with a RESERVATION
3567 	 * CONFLICT status.
3568 	 */
3569 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3570 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3571 			" SPC-2 reservation is held, returning"
3572 			" RESERVATION_CONFLICT\n");
3573 		return TCM_RESERVATION_CONFLICT;
3574 	}
3575 
3576 	/*
3577 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3578 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3579 	 */
3580 	if (!cmd->se_sess)
3581 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3582 
3583 	if (cmd->data_length < 24) {
3584 		pr_warn("SPC-PR: Received PR OUT parameter list"
3585 			" length too small: %u\n", cmd->data_length);
3586 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3587 	}
3588 
3589 	/*
3590 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3591 	 */
3592 	sa = (cdb[1] & 0x1f);
3593 	scope = (cdb[2] & 0xf0);
3594 	type = (cdb[2] & 0x0f);
3595 
3596 	buf = transport_kmap_data_sg(cmd);
3597 	if (!buf)
3598 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3599 
3600 	/*
3601 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3602 	 */
3603 	res_key = get_unaligned_be64(&buf[0]);
3604 	sa_res_key = get_unaligned_be64(&buf[8]);
3605 	/*
3606 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3607 	 * SCSI TransportIDs.
3608 	 */
3609 	if (sa != PRO_REGISTER_AND_MOVE) {
3610 		spec_i_pt = (buf[20] & 0x08);
3611 		all_tg_pt = (buf[20] & 0x04);
3612 		aptpl = (buf[20] & 0x01);
3613 	} else {
3614 		aptpl = (buf[17] & 0x01);
3615 		unreg = (buf[17] & 0x02);
3616 	}
3617 	/*
3618 	 * If the backend device has been configured to force APTPL metadata
3619 	 * write-out, go ahead and propigate aptpl=1 down now.
3620 	 */
3621 	if (dev->dev_attrib.force_pr_aptpl)
3622 		aptpl = 1;
3623 
3624 	transport_kunmap_data_sg(cmd);
3625 	buf = NULL;
3626 
3627 	/*
3628 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3629 	 */
3630 	if (spec_i_pt && (sa != PRO_REGISTER))
3631 		return TCM_INVALID_PARAMETER_LIST;
3632 
3633 	/*
3634 	 * From spc4r17 section 6.14:
3635 	 *
3636 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3637 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3638 	 * the command shall be terminated with CHECK CONDITION status, with
3639 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3640 	 * code set to PARAMETER LIST LENGTH ERROR.
3641 	 */
3642 	if (!spec_i_pt && (sa != PRO_REGISTER_AND_MOVE) &&
3643 	    (cmd->data_length != 24)) {
3644 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3645 			" list length: %u\n", cmd->data_length);
3646 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3647 	}
3648 
3649 	/*
3650 	 * (core_scsi3_emulate_pro_* function parameters
3651 	 * are defined by spc4r17 Table 174:
3652 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3653 	 */
3654 	switch (sa) {
3655 	case PRO_REGISTER:
3656 		ret = core_scsi3_emulate_pro_register(cmd,
3657 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3658 		break;
3659 	case PRO_RESERVE:
3660 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3661 		break;
3662 	case PRO_RELEASE:
3663 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3664 		break;
3665 	case PRO_CLEAR:
3666 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3667 		break;
3668 	case PRO_PREEMPT:
3669 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3670 					res_key, sa_res_key, PREEMPT);
3671 		break;
3672 	case PRO_PREEMPT_AND_ABORT:
3673 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3674 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3675 		break;
3676 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3677 		ret = core_scsi3_emulate_pro_register(cmd,
3678 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3679 		break;
3680 	case PRO_REGISTER_AND_MOVE:
3681 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3682 				sa_res_key, aptpl, unreg);
3683 		break;
3684 	default:
3685 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3686 			" action: 0x%02x\n", sa);
3687 		return TCM_INVALID_CDB_FIELD;
3688 	}
3689 
3690 	if (!ret)
3691 		target_complete_cmd(cmd, GOOD);
3692 	return ret;
3693 }
3694 
3695 /*
3696  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3697  *
3698  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3699  */
3700 static sense_reason_t
3701 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3702 {
3703 	struct se_device *dev = cmd->se_dev;
3704 	struct t10_pr_registration *pr_reg;
3705 	unsigned char *buf;
3706 	u32 add_len = 0, off = 8;
3707 
3708 	if (cmd->data_length < 8) {
3709 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3710 			" too small\n", cmd->data_length);
3711 		return TCM_INVALID_CDB_FIELD;
3712 	}
3713 
3714 	buf = transport_kmap_data_sg(cmd);
3715 	if (!buf)
3716 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3717 
3718 	put_unaligned_be32(dev->t10_pr.pr_generation, buf);
3719 
3720 	spin_lock(&dev->t10_pr.registration_lock);
3721 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3722 			pr_reg_list) {
3723 		/*
3724 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3725 		 * next reservation key list descriptor.
3726 		 */
3727 		if (off + 8 <= cmd->data_length) {
3728 			put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3729 			off += 8;
3730 		}
3731 		/*
3732 		 * SPC5r17: 6.16.2 READ KEYS service action
3733 		 * The ADDITIONAL LENGTH field indicates the number of bytes in
3734 		 * the Reservation key list. The contents of the ADDITIONAL
3735 		 * LENGTH field are not altered based on the allocation length
3736 		 */
3737 		add_len += 8;
3738 	}
3739 	spin_unlock(&dev->t10_pr.registration_lock);
3740 
3741 	put_unaligned_be32(add_len, &buf[4]);
3742 
3743 	transport_kunmap_data_sg(cmd);
3744 
3745 	return 0;
3746 }
3747 
3748 /*
3749  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3750  *
3751  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3752  */
3753 static sense_reason_t
3754 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3755 {
3756 	struct se_device *dev = cmd->se_dev;
3757 	struct t10_pr_registration *pr_reg;
3758 	unsigned char *buf;
3759 	u64 pr_res_key;
3760 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3761 
3762 	if (cmd->data_length < 8) {
3763 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3764 			" too small\n", cmd->data_length);
3765 		return TCM_INVALID_CDB_FIELD;
3766 	}
3767 
3768 	buf = transport_kmap_data_sg(cmd);
3769 	if (!buf)
3770 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3771 
3772 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3773 
3774 	spin_lock(&dev->dev_reservation_lock);
3775 	pr_reg = dev->dev_pr_res_holder;
3776 	if (pr_reg) {
3777 		/*
3778 		 * Set the hardcoded Additional Length
3779 		 */
3780 		put_unaligned_be32(add_len, &buf[4]);
3781 
3782 		if (cmd->data_length < 22)
3783 			goto err;
3784 
3785 		/*
3786 		 * Set the Reservation key.
3787 		 *
3788 		 * From spc4r17, section 5.7.10:
3789 		 * A persistent reservation holder has its reservation key
3790 		 * returned in the parameter data from a PERSISTENT
3791 		 * RESERVE IN command with READ RESERVATION service action as
3792 		 * follows:
3793 		 * a) For a persistent reservation of the type Write Exclusive
3794 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3795 		 *      the reservation key shall be set to zero; or
3796 		 * b) For all other persistent reservation types, the
3797 		 *    reservation key shall be set to the registered
3798 		 *    reservation key for the I_T nexus that holds the
3799 		 *    persistent reservation.
3800 		 */
3801 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3802 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3803 			pr_res_key = 0;
3804 		else
3805 			pr_res_key = pr_reg->pr_res_key;
3806 
3807 		put_unaligned_be64(pr_res_key, &buf[8]);
3808 		/*
3809 		 * Set the SCOPE and TYPE
3810 		 */
3811 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3812 			  (pr_reg->pr_res_type & 0x0f);
3813 	}
3814 
3815 err:
3816 	spin_unlock(&dev->dev_reservation_lock);
3817 	transport_kunmap_data_sg(cmd);
3818 
3819 	return 0;
3820 }
3821 
3822 /*
3823  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3824  *
3825  * See spc4r17 section 6.13.4 Table 165
3826  */
3827 static sense_reason_t
3828 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3829 {
3830 	struct se_device *dev = cmd->se_dev;
3831 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3832 	unsigned char *buf;
3833 	u16 add_len = 8; /* Hardcoded to 8. */
3834 
3835 	if (cmd->data_length < 6) {
3836 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3837 			" %u too small\n", cmd->data_length);
3838 		return TCM_INVALID_CDB_FIELD;
3839 	}
3840 
3841 	buf = transport_kmap_data_sg(cmd);
3842 	if (!buf)
3843 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3844 
3845 	put_unaligned_be16(add_len, &buf[0]);
3846 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3847 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3848 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3849 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3850 	/*
3851 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3852 	 * set the TMV: Task Mask Valid bit.
3853 	 */
3854 	buf[3] |= 0x80;
3855 	/*
3856 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3857 	 */
3858 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3859 	/*
3860 	 * PTPL_A: Persistence across Target Power Loss Active bit
3861 	 */
3862 	if (pr_tmpl->pr_aptpl_active)
3863 		buf[3] |= 0x01;
3864 	/*
3865 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3866 	 */
3867 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3868 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3869 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3870 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3871 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3872 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3873 
3874 	transport_kunmap_data_sg(cmd);
3875 
3876 	return 0;
3877 }
3878 
3879 /*
3880  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3881  *
3882  * See spc4r17 section 6.13.5 Table 168 and 169
3883  */
3884 static sense_reason_t
3885 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3886 {
3887 	struct se_device *dev = cmd->se_dev;
3888 	struct se_node_acl *se_nacl;
3889 	struct se_portal_group *se_tpg;
3890 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3891 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3892 	unsigned char *buf;
3893 	u32 add_desc_len = 0, add_len = 0;
3894 	u32 off = 8; /* off into first Full Status descriptor */
3895 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3896 	int exp_desc_len, desc_len;
3897 	bool all_reg = false;
3898 
3899 	if (cmd->data_length < 8) {
3900 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3901 			" too small\n", cmd->data_length);
3902 		return TCM_INVALID_CDB_FIELD;
3903 	}
3904 
3905 	buf = transport_kmap_data_sg(cmd);
3906 	if (!buf)
3907 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3908 
3909 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3910 
3911 	spin_lock(&dev->dev_reservation_lock);
3912 	if (dev->dev_pr_res_holder) {
3913 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3914 
3915 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3916 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3917 			all_reg = true;
3918 			pr_res_type = pr_holder->pr_res_type;
3919 			pr_res_scope = pr_holder->pr_res_scope;
3920 		}
3921 	}
3922 	spin_unlock(&dev->dev_reservation_lock);
3923 
3924 	spin_lock(&pr_tmpl->registration_lock);
3925 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3926 			&pr_tmpl->registration_list, pr_reg_list) {
3927 
3928 		se_nacl = pr_reg->pr_reg_nacl;
3929 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3930 		add_desc_len = 0;
3931 
3932 		atomic_inc_mb(&pr_reg->pr_res_holders);
3933 		spin_unlock(&pr_tmpl->registration_lock);
3934 		/*
3935 		 * Determine expected length of $FABRIC_MOD specific
3936 		 * TransportID full status descriptor..
3937 		 */
3938 		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
3939 					&format_code);
3940 		if (exp_desc_len < 0 ||
3941 		    exp_desc_len + add_len > cmd->data_length) {
3942 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3943 				" out of buffer: %d\n", cmd->data_length);
3944 			spin_lock(&pr_tmpl->registration_lock);
3945 			atomic_dec_mb(&pr_reg->pr_res_holders);
3946 			break;
3947 		}
3948 		/*
3949 		 * Set RESERVATION KEY
3950 		 */
3951 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3952 		off += 8;
3953 		off += 4; /* Skip Over Reserved area */
3954 
3955 		/*
3956 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3957 		 */
3958 		if (pr_reg->pr_reg_all_tg_pt)
3959 			buf[off] = 0x02;
3960 		/*
3961 		 * The struct se_lun pointer will be present for the
3962 		 * reservation holder for PR_HOLDER bit.
3963 		 *
3964 		 * Also, if this registration is the reservation
3965 		 * holder or there is an All Registrants reservation
3966 		 * active, fill in SCOPE and TYPE in the next byte.
3967 		 */
3968 		if (pr_reg->pr_res_holder) {
3969 			buf[off++] |= 0x01;
3970 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3971 				     (pr_reg->pr_res_type & 0x0f);
3972 		} else if (all_reg) {
3973 			buf[off++] |= 0x01;
3974 			buf[off++] = (pr_res_scope & 0xf0) |
3975 				     (pr_res_type & 0x0f);
3976 		} else {
3977 			off += 2;
3978 		}
3979 
3980 		off += 4; /* Skip over reserved area */
3981 		/*
3982 		 * From spc4r17 6.3.15:
3983 		 *
3984 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
3985 		 * IDENTIFIER field contains the relative port identifier (see
3986 		 * 3.1.120) of the target port that is part of the I_T nexus
3987 		 * described by this full status descriptor. If the ALL_TG_PT
3988 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
3989 		 * IDENTIFIER field are not defined by this standard.
3990 		 */
3991 		if (!pr_reg->pr_reg_all_tg_pt) {
3992 			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;
3993 
3994 			put_unaligned_be16(sep_rtpi, &buf[off]);
3995 			off += 2;
3996 		} else
3997 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
3998 
3999 		buf[off+4] = se_tpg->proto_id;
4000 
4001 		/*
4002 		 * Now, have the $FABRIC_MOD fill in the transport ID.
4003 		 */
4004 		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
4005 				&format_code, &buf[off+4]);
4006 
4007 		spin_lock(&pr_tmpl->registration_lock);
4008 		atomic_dec_mb(&pr_reg->pr_res_holders);
4009 
4010 		if (desc_len < 0)
4011 			break;
4012 		/*
4013 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4014 		 */
4015 		put_unaligned_be32(desc_len, &buf[off]);
4016 		off += 4;
4017 		/*
4018 		 * Size of full desctipor header minus TransportID
4019 		 * containing $FABRIC_MOD specific) initiator device/port
4020 		 * WWN information.
4021 		 *
4022 		 *  See spc4r17 Section 6.13.5 Table 169
4023 		 */
4024 		add_desc_len = (24 + desc_len);
4025 
4026 		off += desc_len;
4027 		add_len += add_desc_len;
4028 	}
4029 	spin_unlock(&pr_tmpl->registration_lock);
4030 	/*
4031 	 * Set ADDITIONAL_LENGTH
4032 	 */
4033 	put_unaligned_be32(add_len, &buf[4]);
4034 
4035 	transport_kunmap_data_sg(cmd);
4036 
4037 	return 0;
4038 }
4039 
4040 sense_reason_t
4041 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4042 {
4043 	sense_reason_t ret;
4044 
4045 	/*
4046 	 * Following spc2r20 5.5.1 Reservations overview:
4047 	 *
4048 	 * If a logical unit has been reserved by any RESERVE command and is
4049 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4050 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4051 	 * initiator or service action and shall terminate with a RESERVATION
4052 	 * CONFLICT status.
4053 	 */
4054 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4055 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4056 			" SPC-2 reservation is held, returning"
4057 			" RESERVATION_CONFLICT\n");
4058 		return TCM_RESERVATION_CONFLICT;
4059 	}
4060 
4061 	switch (cmd->t_task_cdb[1] & 0x1f) {
4062 	case PRI_READ_KEYS:
4063 		ret = core_scsi3_pri_read_keys(cmd);
4064 		break;
4065 	case PRI_READ_RESERVATION:
4066 		ret = core_scsi3_pri_read_reservation(cmd);
4067 		break;
4068 	case PRI_REPORT_CAPABILITIES:
4069 		ret = core_scsi3_pri_report_capabilities(cmd);
4070 		break;
4071 	case PRI_READ_FULL_STATUS:
4072 		ret = core_scsi3_pri_read_full_status(cmd);
4073 		break;
4074 	default:
4075 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4076 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4077 		return TCM_INVALID_CDB_FIELD;
4078 	}
4079 
4080 	if (!ret)
4081 		target_complete_cmd(cmd, GOOD);
4082 	return ret;
4083 }
4084 
4085 sense_reason_t
4086 target_check_reservation(struct se_cmd *cmd)
4087 {
4088 	struct se_device *dev = cmd->se_dev;
4089 	sense_reason_t ret;
4090 
4091 	if (!cmd->se_sess)
4092 		return 0;
4093 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4094 		return 0;
4095 	if (!dev->dev_attrib.emulate_pr)
4096 		return 0;
4097 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
4098 		return 0;
4099 
4100 	spin_lock(&dev->dev_reservation_lock);
4101 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4102 		ret = target_scsi2_reservation_check(cmd);
4103 	else
4104 		ret = target_scsi3_pr_reservation_check(cmd);
4105 	spin_unlock(&dev->dev_reservation_lock);
4106 
4107 	return ret;
4108 }
4109