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->get_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->get_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->get_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->get_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->get_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->get_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->get_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->get_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->get_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 /*
1294  * Called with struct t10_reservation->registration_lock held.
1295  */
1296 static void __core_scsi3_free_registration(
1297 	struct se_device *dev,
1298 	struct t10_pr_registration *pr_reg,
1299 	struct list_head *preempt_and_abort_list,
1300 	int dec_holders)
1301 	__releases(&pr_tmpl->registration_lock)
1302 	__acquires(&pr_tmpl->registration_lock)
1303 {
1304 	const struct target_core_fabric_ops *tfo =
1305 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1306 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1307 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1308 	struct se_dev_entry *deve;
1309 	char i_buf[PR_REG_ISID_ID_LEN];
1310 
1311 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1312 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1313 
1314 	if (!list_empty(&pr_reg->pr_reg_list))
1315 		list_del(&pr_reg->pr_reg_list);
1316 	/*
1317 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1318 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1319 	 */
1320 	if (dec_holders)
1321 		core_scsi3_put_pr_reg(pr_reg);
1322 
1323 	spin_unlock(&pr_tmpl->registration_lock);
1324 	/*
1325 	 * Wait until all reference from any other I_T nexuses for this
1326 	 * *pr_reg have been released.  Because list_del() is called above,
1327 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1328 	 * count back to zero, and we release *pr_reg.
1329 	 */
1330 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1331 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1332 				tfo->get_fabric_name());
1333 		cpu_relax();
1334 	}
1335 
1336 	rcu_read_lock();
1337 	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
1338 	if (deve)
1339 		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1340 	rcu_read_unlock();
1341 
1342 	spin_lock(&pr_tmpl->registration_lock);
1343 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1344 		" Node: %s%s\n", tfo->get_fabric_name(),
1345 		pr_reg->pr_reg_nacl->initiatorname,
1346 		i_buf);
1347 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1348 		" Port(s)\n", tfo->get_fabric_name(),
1349 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1350 		dev->transport->name);
1351 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1352 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1353 		pr_reg->pr_res_generation);
1354 
1355 	if (!preempt_and_abort_list) {
1356 		pr_reg->pr_reg_deve = NULL;
1357 		pr_reg->pr_reg_nacl = NULL;
1358 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1359 		return;
1360 	}
1361 	/*
1362 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1363 	 * are released once the ABORT_TASK_SET has completed..
1364 	 */
1365 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1366 }
1367 
1368 void core_scsi3_free_pr_reg_from_nacl(
1369 	struct se_device *dev,
1370 	struct se_node_acl *nacl)
1371 {
1372 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1373 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1374 	bool free_reg = false;
1375 	/*
1376 	 * If the passed se_node_acl matches the reservation holder,
1377 	 * release the reservation.
1378 	 */
1379 	spin_lock(&dev->dev_reservation_lock);
1380 	pr_res_holder = dev->dev_pr_res_holder;
1381 	if ((pr_res_holder != NULL) &&
1382 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1383 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1384 		free_reg = true;
1385 	}
1386 	spin_unlock(&dev->dev_reservation_lock);
1387 	/*
1388 	 * Release any registration associated with the struct se_node_acl.
1389 	 */
1390 	spin_lock(&pr_tmpl->registration_lock);
1391 	if (pr_res_holder && free_reg)
1392 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1393 
1394 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1395 			&pr_tmpl->registration_list, pr_reg_list) {
1396 
1397 		if (pr_reg->pr_reg_nacl != nacl)
1398 			continue;
1399 
1400 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1401 	}
1402 	spin_unlock(&pr_tmpl->registration_lock);
1403 }
1404 
1405 void core_scsi3_free_all_registrations(
1406 	struct se_device *dev)
1407 {
1408 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1409 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1410 
1411 	spin_lock(&dev->dev_reservation_lock);
1412 	pr_res_holder = dev->dev_pr_res_holder;
1413 	if (pr_res_holder != NULL) {
1414 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1415 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1416 						  pr_res_holder, 0, 0);
1417 	}
1418 	spin_unlock(&dev->dev_reservation_lock);
1419 
1420 	spin_lock(&pr_tmpl->registration_lock);
1421 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1422 			&pr_tmpl->registration_list, pr_reg_list) {
1423 
1424 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1425 	}
1426 	spin_unlock(&pr_tmpl->registration_lock);
1427 
1428 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1429 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1430 				pr_reg_aptpl_list) {
1431 		list_del(&pr_reg->pr_reg_aptpl_list);
1432 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1433 	}
1434 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1435 }
1436 
1437 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1438 {
1439 	return target_depend_item(&tpg->tpg_group.cg_item);
1440 }
1441 
1442 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1443 {
1444 	target_undepend_item(&tpg->tpg_group.cg_item);
1445 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1446 }
1447 
1448 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1449 {
1450 	if (nacl->dynamic_node_acl)
1451 		return 0;
1452 	return target_depend_item(&nacl->acl_group.cg_item);
1453 }
1454 
1455 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1456 {
1457 	if (!nacl->dynamic_node_acl)
1458 		target_undepend_item(&nacl->acl_group.cg_item);
1459 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1460 }
1461 
1462 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1463 {
1464 	struct se_lun_acl *lun_acl;
1465 
1466 	/*
1467 	 * For nacl->dynamic_node_acl=1
1468 	 */
1469 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1470 				kref_read(&se_deve->pr_kref) != 0);
1471 	if (!lun_acl)
1472 		return 0;
1473 
1474 	return target_depend_item(&lun_acl->se_lun_group.cg_item);
1475 }
1476 
1477 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1478 {
1479 	struct se_lun_acl *lun_acl;
1480 
1481 	/*
1482 	 * For nacl->dynamic_node_acl=1
1483 	 */
1484 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1485 				kref_read(&se_deve->pr_kref) != 0);
1486 	if (!lun_acl) {
1487 		kref_put(&se_deve->pr_kref, target_pr_kref_release);
1488 		return;
1489 	}
1490 
1491 	target_undepend_item(&lun_acl->se_lun_group.cg_item);
1492 	kref_put(&se_deve->pr_kref, target_pr_kref_release);
1493 }
1494 
1495 static sense_reason_t
1496 core_scsi3_decode_spec_i_port(
1497 	struct se_cmd *cmd,
1498 	struct se_portal_group *tpg,
1499 	unsigned char *l_isid,
1500 	u64 sa_res_key,
1501 	int all_tg_pt,
1502 	int aptpl)
1503 {
1504 	struct se_device *dev = cmd->se_dev;
1505 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1506 	struct se_session *se_sess = cmd->se_sess;
1507 	struct se_node_acl *dest_node_acl = NULL;
1508 	struct se_dev_entry *dest_se_deve = NULL;
1509 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1510 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1511 	LIST_HEAD(tid_dest_list);
1512 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1513 	unsigned char *buf, *ptr, proto_ident;
1514 	const unsigned char *i_str = NULL;
1515 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1516 	sense_reason_t ret;
1517 	u32 tpdl, tid_len = 0;
1518 	u32 dest_rtpi = 0;
1519 
1520 	/*
1521 	 * Allocate a struct pr_transport_id_holder and setup the
1522 	 * local_node_acl pointer and add to struct list_head tid_dest_list
1523 	 * for add registration processing in the loop of tid_dest_list below.
1524 	 */
1525 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1526 	if (!tidh_new) {
1527 		pr_err("Unable to allocate tidh_new\n");
1528 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1529 	}
1530 	INIT_LIST_HEAD(&tidh_new->dest_list);
1531 	tidh_new->dest_tpg = tpg;
1532 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1533 
1534 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1535 				se_sess->se_node_acl, cmd->se_lun,
1536 				NULL, cmd->orig_fe_lun, l_isid,
1537 				sa_res_key, all_tg_pt, aptpl);
1538 	if (!local_pr_reg) {
1539 		kfree(tidh_new);
1540 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1541 	}
1542 	tidh_new->dest_pr_reg = local_pr_reg;
1543 	/*
1544 	 * The local I_T nexus does not hold any configfs dependances,
1545 	 * so we set tidh_new->dest_se_deve to NULL to prevent the
1546 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1547 	 */
1548 	tidh_new->dest_se_deve = NULL;
1549 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1550 
1551 	if (cmd->data_length < 28) {
1552 		pr_warn("SPC-PR: Received PR OUT parameter list"
1553 			" length too small: %u\n", cmd->data_length);
1554 		ret = TCM_INVALID_PARAMETER_LIST;
1555 		goto out;
1556 	}
1557 
1558 	buf = transport_kmap_data_sg(cmd);
1559 	if (!buf) {
1560 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1561 		goto out;
1562 	}
1563 
1564 	/*
1565 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1566 	 * first extract TransportID Parameter Data Length, and make sure
1567 	 * the value matches up to the SCSI expected data transfer length.
1568 	 */
1569 	tpdl = get_unaligned_be32(&buf[24]);
1570 
1571 	if ((tpdl + 28) != cmd->data_length) {
1572 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1573 			" does not equal CDB data_length: %u\n", tpdl,
1574 			cmd->data_length);
1575 		ret = TCM_INVALID_PARAMETER_LIST;
1576 		goto out_unmap;
1577 	}
1578 	/*
1579 	 * Start processing the received transport IDs using the
1580 	 * receiving I_T Nexus portal's fabric dependent methods to
1581 	 * obtain the SCSI Initiator Port/Device Identifiers.
1582 	 */
1583 	ptr = &buf[28];
1584 
1585 	while (tpdl > 0) {
1586 		struct se_lun *dest_lun, *tmp_lun;
1587 
1588 		proto_ident = (ptr[0] & 0x0f);
1589 		dest_tpg = NULL;
1590 
1591 		spin_lock(&dev->se_port_lock);
1592 		list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
1593 			tmp_tpg = tmp_lun->lun_tpg;
1594 
1595 			/*
1596 			 * Look for the matching proto_ident provided by
1597 			 * the received TransportID
1598 			 */
1599 			if (tmp_tpg->proto_id != proto_ident)
1600 				continue;
1601 			dest_rtpi = tmp_lun->lun_rtpi;
1602 
1603 			i_str = target_parse_pr_out_transport_id(tmp_tpg,
1604 					ptr, &tid_len, &iport_ptr);
1605 			if (!i_str)
1606 				continue;
1607 
1608 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1609 			spin_unlock(&dev->se_port_lock);
1610 
1611 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1612 				pr_err(" core_scsi3_tpg_depend_item()"
1613 					" for tmp_tpg\n");
1614 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1615 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1616 				goto out_unmap;
1617 			}
1618 			/*
1619 			 * Locate the destination initiator ACL to be registered
1620 			 * from the decoded fabric module specific TransportID
1621 			 * at *i_str.
1622 			 */
1623 			mutex_lock(&tmp_tpg->acl_node_mutex);
1624 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1625 						tmp_tpg, i_str);
1626 			if (dest_node_acl)
1627 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1628 			mutex_unlock(&tmp_tpg->acl_node_mutex);
1629 
1630 			if (!dest_node_acl) {
1631 				core_scsi3_tpg_undepend_item(tmp_tpg);
1632 				spin_lock(&dev->se_port_lock);
1633 				continue;
1634 			}
1635 
1636 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1637 				pr_err("configfs_depend_item() failed"
1638 					" for dest_node_acl->acl_group\n");
1639 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1640 				core_scsi3_tpg_undepend_item(tmp_tpg);
1641 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1642 				goto out_unmap;
1643 			}
1644 
1645 			dest_tpg = tmp_tpg;
1646 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1647 				" %s Port RTPI: %hu\n",
1648 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1649 				dest_node_acl->initiatorname, dest_rtpi);
1650 
1651 			spin_lock(&dev->se_port_lock);
1652 			break;
1653 		}
1654 		spin_unlock(&dev->se_port_lock);
1655 
1656 		if (!dest_tpg) {
1657 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1658 					" dest_tpg\n");
1659 			ret = TCM_INVALID_PARAMETER_LIST;
1660 			goto out_unmap;
1661 		}
1662 
1663 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1664 			" tid_len: %d for %s + %s\n",
1665 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1666 			tpdl, tid_len, i_str, iport_ptr);
1667 
1668 		if (tid_len > tpdl) {
1669 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1670 				" %u for Transport ID: %s\n", tid_len, ptr);
1671 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1672 			core_scsi3_tpg_undepend_item(dest_tpg);
1673 			ret = TCM_INVALID_PARAMETER_LIST;
1674 			goto out_unmap;
1675 		}
1676 		/*
1677 		 * Locate the desintation struct se_dev_entry pointer for matching
1678 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1679 		 * Target Port.
1680 		 */
1681 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1682 					dest_rtpi);
1683 		if (!dest_se_deve) {
1684 			pr_err("Unable to locate %s dest_se_deve"
1685 				" from destination RTPI: %hu\n",
1686 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1687 				dest_rtpi);
1688 
1689 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1690 			core_scsi3_tpg_undepend_item(dest_tpg);
1691 			ret = TCM_INVALID_PARAMETER_LIST;
1692 			goto out_unmap;
1693 		}
1694 
1695 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1696 			pr_err("core_scsi3_lunacl_depend_item()"
1697 					" failed\n");
1698 			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
1699 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1700 			core_scsi3_tpg_undepend_item(dest_tpg);
1701 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1702 			goto out_unmap;
1703 		}
1704 
1705 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1706 			" dest_se_deve mapped_lun: %llu\n",
1707 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1708 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1709 
1710 		/*
1711 		 * Skip any TransportIDs that already have a registration for
1712 		 * this target port.
1713 		 */
1714 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1715 					iport_ptr);
1716 		if (pr_reg_e) {
1717 			core_scsi3_put_pr_reg(pr_reg_e);
1718 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1719 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1720 			core_scsi3_tpg_undepend_item(dest_tpg);
1721 			ptr += tid_len;
1722 			tpdl -= tid_len;
1723 			tid_len = 0;
1724 			continue;
1725 		}
1726 		/*
1727 		 * Allocate a struct pr_transport_id_holder and setup
1728 		 * the dest_node_acl and dest_se_deve pointers for the
1729 		 * loop below.
1730 		 */
1731 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1732 				GFP_KERNEL);
1733 		if (!tidh_new) {
1734 			pr_err("Unable to allocate tidh_new\n");
1735 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1736 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1737 			core_scsi3_tpg_undepend_item(dest_tpg);
1738 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1739 			goto out_unmap;
1740 		}
1741 		INIT_LIST_HEAD(&tidh_new->dest_list);
1742 		tidh_new->dest_tpg = dest_tpg;
1743 		tidh_new->dest_node_acl = dest_node_acl;
1744 		tidh_new->dest_se_deve = dest_se_deve;
1745 
1746 		/*
1747 		 * Allocate, but do NOT add the registration for the
1748 		 * TransportID referenced SCSI Initiator port.  This
1749 		 * done because of the following from spc4r17 in section
1750 		 * 6.14.3 wrt SPEC_I_PT:
1751 		 *
1752 		 * "If a registration fails for any initiator port (e.g., if th
1753 		 * logical unit does not have enough resources available to
1754 		 * hold the registration information), no registrations shall be
1755 		 * made, and the command shall be terminated with
1756 		 * CHECK CONDITION status."
1757 		 *
1758 		 * That means we call __core_scsi3_alloc_registration() here,
1759 		 * and then call __core_scsi3_add_registration() in the
1760 		 * 2nd loop which will never fail.
1761 		 */
1762 		dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
1763 				kref_read(&dest_se_deve->pr_kref) != 0);
1764 
1765 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1766 					dest_node_acl, dest_lun, dest_se_deve,
1767 					dest_se_deve->mapped_lun, iport_ptr,
1768 					sa_res_key, all_tg_pt, aptpl);
1769 		if (!dest_pr_reg) {
1770 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1771 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1772 			core_scsi3_tpg_undepend_item(dest_tpg);
1773 			kfree(tidh_new);
1774 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1775 			goto out_unmap;
1776 		}
1777 		tidh_new->dest_pr_reg = dest_pr_reg;
1778 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1779 
1780 		ptr += tid_len;
1781 		tpdl -= tid_len;
1782 		tid_len = 0;
1783 
1784 	}
1785 
1786 	transport_kunmap_data_sg(cmd);
1787 
1788 	/*
1789 	 * Go ahead and create a registrations from tid_dest_list for the
1790 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1791 	 * and dest_se_deve.
1792 	 *
1793 	 * The SA Reservation Key from the PROUT is set for the
1794 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1795 	 * means that the TransportID Initiator port will be
1796 	 * registered on all of the target ports in the SCSI target device
1797 	 * ALL_TG_PT=0 means the registration will only be for the
1798 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1799 	 * was received.
1800 	 */
1801 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1802 		dest_tpg = tidh->dest_tpg;
1803 		dest_node_acl = tidh->dest_node_acl;
1804 		dest_se_deve = tidh->dest_se_deve;
1805 		dest_pr_reg = tidh->dest_pr_reg;
1806 
1807 		list_del(&tidh->dest_list);
1808 		kfree(tidh);
1809 
1810 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1811 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1812 
1813 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1814 					dest_pr_reg, 0, 0);
1815 
1816 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1817 			" registered Transport ID for Node: %s%s Mapped LUN:"
1818 			" %llu\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1819 			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
1820 			dest_se_deve->mapped_lun : 0);
1821 
1822 		if (!dest_se_deve) {
1823 			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1824 				 target_pr_kref_release);
1825 			continue;
1826 		}
1827 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1828 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1829 		core_scsi3_tpg_undepend_item(dest_tpg);
1830 	}
1831 
1832 	return 0;
1833 out_unmap:
1834 	transport_kunmap_data_sg(cmd);
1835 out:
1836 	/*
1837 	 * For the failure case, release everything from tid_dest_list
1838 	 * including *dest_pr_reg and the configfs dependances..
1839 	 */
1840 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1841 		dest_tpg = tidh->dest_tpg;
1842 		dest_node_acl = tidh->dest_node_acl;
1843 		dest_se_deve = tidh->dest_se_deve;
1844 		dest_pr_reg = tidh->dest_pr_reg;
1845 
1846 		list_del(&tidh->dest_list);
1847 		kfree(tidh);
1848 		/*
1849 		 * Release any extra ALL_TG_PT=1 registrations for
1850 		 * the SPEC_I_PT=1 case.
1851 		 */
1852 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1853 				&dest_pr_reg->pr_reg_atp_list,
1854 				pr_reg_atp_mem_list) {
1855 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1856 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1857 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1858 		}
1859 
1860 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1861 
1862 		if (!dest_se_deve) {
1863 			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1864 				 target_pr_kref_release);
1865 			continue;
1866 		}
1867 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1868 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1869 		core_scsi3_tpg_undepend_item(dest_tpg);
1870 	}
1871 	return ret;
1872 }
1873 
1874 static int core_scsi3_update_aptpl_buf(
1875 	struct se_device *dev,
1876 	unsigned char *buf,
1877 	u32 pr_aptpl_buf_len)
1878 {
1879 	struct se_portal_group *tpg;
1880 	struct t10_pr_registration *pr_reg;
1881 	unsigned char tmp[512], isid_buf[32];
1882 	ssize_t len = 0;
1883 	int reg_count = 0;
1884 	int ret = 0;
1885 
1886 	spin_lock(&dev->dev_reservation_lock);
1887 	spin_lock(&dev->t10_pr.registration_lock);
1888 	/*
1889 	 * Walk the registration list..
1890 	 */
1891 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1892 			pr_reg_list) {
1893 
1894 		tmp[0] = '\0';
1895 		isid_buf[0] = '\0';
1896 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1897 		/*
1898 		 * Write out any ISID value to APTPL metadata that was included
1899 		 * in the original registration.
1900 		 */
1901 		if (pr_reg->isid_present_at_reg)
1902 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1903 					pr_reg->pr_reg_isid);
1904 		/*
1905 		 * Include special metadata if the pr_reg matches the
1906 		 * reservation holder.
1907 		 */
1908 		if (dev->dev_pr_res_holder == pr_reg) {
1909 			snprintf(tmp, 512, "PR_REG_START: %d"
1910 				"\ninitiator_fabric=%s\n"
1911 				"initiator_node=%s\n%s"
1912 				"sa_res_key=%llu\n"
1913 				"res_holder=1\nres_type=%02x\n"
1914 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1915 				"mapped_lun=%llu\n", reg_count,
1916 				tpg->se_tpg_tfo->get_fabric_name(),
1917 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1918 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1919 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1920 				pr_reg->pr_res_mapped_lun);
1921 		} else {
1922 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1923 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1924 				"sa_res_key=%llu\nres_holder=0\n"
1925 				"res_all_tg_pt=%d\nmapped_lun=%llu\n",
1926 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1927 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1928 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1929 				pr_reg->pr_res_mapped_lun);
1930 		}
1931 
1932 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1933 			pr_err("Unable to update renaming APTPL metadata,"
1934 			       " reallocating larger buffer\n");
1935 			ret = -EMSGSIZE;
1936 			goto out;
1937 		}
1938 		len += sprintf(buf+len, "%s", tmp);
1939 
1940 		/*
1941 		 * Include information about the associated SCSI target port.
1942 		 */
1943 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1944 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%llu\nPR_REG_END:"
1945 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1946 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1947 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1948 			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
1949 			reg_count);
1950 
1951 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1952 			pr_err("Unable to update renaming APTPL metadata,"
1953 			       " reallocating larger buffer\n");
1954 			ret = -EMSGSIZE;
1955 			goto out;
1956 		}
1957 		len += sprintf(buf+len, "%s", tmp);
1958 		reg_count++;
1959 	}
1960 
1961 	if (!reg_count)
1962 		len += sprintf(buf+len, "No Registrations or Reservations");
1963 
1964 out:
1965 	spin_unlock(&dev->t10_pr.registration_lock);
1966 	spin_unlock(&dev->dev_reservation_lock);
1967 
1968 	return ret;
1969 }
1970 
1971 static int __core_scsi3_write_aptpl_to_file(
1972 	struct se_device *dev,
1973 	unsigned char *buf)
1974 {
1975 	struct t10_wwn *wwn = &dev->t10_wwn;
1976 	struct file *file;
1977 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1978 	char *path;
1979 	u32 pr_aptpl_buf_len;
1980 	int ret;
1981 	loff_t pos = 0;
1982 
1983 	path = kasprintf(GFP_KERNEL, "%s/pr/aptpl_%s", db_root,
1984 			&wwn->unit_serial[0]);
1985 	if (!path)
1986 		return -ENOMEM;
1987 
1988 	file = filp_open(path, flags, 0600);
1989 	if (IS_ERR(file)) {
1990 		pr_err("filp_open(%s) for APTPL metadata"
1991 			" failed\n", path);
1992 		kfree(path);
1993 		return PTR_ERR(file);
1994 	}
1995 
1996 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1997 
1998 	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);
1999 
2000 	if (ret < 0)
2001 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2002 	fput(file);
2003 	kfree(path);
2004 
2005 	return (ret < 0) ? -EIO : 0;
2006 }
2007 
2008 /*
2009  * Clear the APTPL metadata if APTPL has been disabled, otherwise
2010  * write out the updated metadata to struct file for this SCSI device.
2011  */
2012 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
2013 {
2014 	unsigned char *buf;
2015 	int rc, len = PR_APTPL_BUF_LEN;
2016 
2017 	if (!aptpl) {
2018 		char *null_buf = "No Registrations or Reservations\n";
2019 
2020 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
2021 		dev->t10_pr.pr_aptpl_active = 0;
2022 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
2023 
2024 		if (rc)
2025 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2026 
2027 		return 0;
2028 	}
2029 retry:
2030 	buf = vzalloc(len);
2031 	if (!buf)
2032 		return TCM_OUT_OF_RESOURCES;
2033 
2034 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
2035 	if (rc < 0) {
2036 		vfree(buf);
2037 		len *= 2;
2038 		goto retry;
2039 	}
2040 
2041 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2042 	if (rc != 0) {
2043 		pr_err("SPC-3 PR: Could not update APTPL\n");
2044 		vfree(buf);
2045 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2046 	}
2047 	dev->t10_pr.pr_aptpl_active = 1;
2048 	vfree(buf);
2049 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2050 	return 0;
2051 }
2052 
2053 static sense_reason_t
2054 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2055 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2056 {
2057 	struct se_session *se_sess = cmd->se_sess;
2058 	struct se_device *dev = cmd->se_dev;
2059 	struct se_lun *se_lun = cmd->se_lun;
2060 	struct se_portal_group *se_tpg;
2061 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2062 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2063 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2064 	sense_reason_t ret = TCM_NO_SENSE;
2065 	int pr_holder = 0, type;
2066 
2067 	if (!se_sess || !se_lun) {
2068 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2069 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2070 	}
2071 	se_tpg = se_sess->se_tpg;
2072 
2073 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2074 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2075 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2076 				PR_REG_ISID_LEN);
2077 		isid_ptr = &isid_buf[0];
2078 	}
2079 	/*
2080 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2081 	 */
2082 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2083 	if (!pr_reg) {
2084 		if (res_key) {
2085 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2086 				" for SA REGISTER, returning CONFLICT\n");
2087 			return TCM_RESERVATION_CONFLICT;
2088 		}
2089 		/*
2090 		 * Do nothing but return GOOD status.
2091 		 */
2092 		if (!sa_res_key)
2093 			return 0;
2094 
2095 		if (!spec_i_pt) {
2096 			/*
2097 			 * Perform the Service Action REGISTER on the Initiator
2098 			 * Port Endpoint that the PRO was received from on the
2099 			 * Logical Unit of the SCSI device server.
2100 			 */
2101 			if (core_scsi3_alloc_registration(cmd->se_dev,
2102 					se_sess->se_node_acl, cmd->se_lun,
2103 					NULL, cmd->orig_fe_lun, isid_ptr,
2104 					sa_res_key, all_tg_pt, aptpl,
2105 					register_type, 0)) {
2106 				pr_err("Unable to allocate"
2107 					" struct t10_pr_registration\n");
2108 				return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
2109 			}
2110 		} else {
2111 			/*
2112 			 * Register both the Initiator port that received
2113 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2114 			 * TransportID from Parameter list and loop through
2115 			 * fabric dependent parameter list while calling
2116 			 * logic from of core_scsi3_alloc_registration() for
2117 			 * each TransportID provided SCSI Initiator Port/Device
2118 			 */
2119 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2120 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2121 			if (ret != 0)
2122 				return ret;
2123 		}
2124 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2125 	}
2126 
2127 	/* ok, existing registration */
2128 
2129 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2130 		pr_err("SPC-3 PR REGISTER: Received"
2131 		       " res_key: 0x%016Lx does not match"
2132 		       " existing SA REGISTER res_key:"
2133 		       " 0x%016Lx\n", res_key,
2134 		       pr_reg->pr_res_key);
2135 		ret = TCM_RESERVATION_CONFLICT;
2136 		goto out;
2137 	}
2138 
2139 	if (spec_i_pt) {
2140 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2141 			" set on a registered nexus\n");
2142 		ret = TCM_INVALID_PARAMETER_LIST;
2143 		goto out;
2144 	}
2145 
2146 	/*
2147 	 * An existing ALL_TG_PT=1 registration being released
2148 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2149 	 */
2150 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2151 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2152 			" registration exists, but ALL_TG_PT=1 bit not"
2153 			" present in received PROUT\n");
2154 		ret = TCM_INVALID_CDB_FIELD;
2155 		goto out;
2156 	}
2157 
2158 	/*
2159 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2160 	 */
2161 	if (sa_res_key) {
2162 		/*
2163 		 * Increment PRgeneration counter for struct se_device"
2164 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2165 		 * READ_KEYS service action.
2166 		 */
2167 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2168 		pr_reg->pr_res_key = sa_res_key;
2169 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2170 			 " Key for %s to: 0x%016Lx PRgeneration:"
2171 			 " 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2172 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2173 			 pr_reg->pr_reg_nacl->initiatorname,
2174 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2175 
2176 	} else {
2177 		/*
2178 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2179 		 */
2180 		type = pr_reg->pr_res_type;
2181 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2182 							      pr_reg);
2183 		if (pr_holder < 0) {
2184 			ret = TCM_RESERVATION_CONFLICT;
2185 			goto out;
2186 		}
2187 
2188 		spin_lock(&pr_tmpl->registration_lock);
2189 		/*
2190 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2191 		 * and matching pr_res_key.
2192 		 */
2193 		if (pr_reg->pr_reg_all_tg_pt) {
2194 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2195 					&pr_tmpl->registration_list,
2196 					pr_reg_list) {
2197 
2198 				if (!pr_reg_p->pr_reg_all_tg_pt)
2199 					continue;
2200 				if (pr_reg_p->pr_res_key != res_key)
2201 					continue;
2202 				if (pr_reg == pr_reg_p)
2203 					continue;
2204 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2205 					   pr_reg_p->pr_reg_nacl->initiatorname))
2206 					continue;
2207 
2208 				__core_scsi3_free_registration(dev,
2209 						pr_reg_p, NULL, 0);
2210 			}
2211 		}
2212 
2213 		/*
2214 		 * Release the calling I_T Nexus registration now..
2215 		 */
2216 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2217 		pr_reg = NULL;
2218 
2219 		/*
2220 		 * From spc4r17, section 5.7.11.3 Unregistering
2221 		 *
2222 		 * If the persistent reservation is a registrants only
2223 		 * type, the device server shall establish a unit
2224 		 * attention condition for the initiator port associated
2225 		 * with every registered I_T nexus except for the I_T
2226 		 * nexus on which the PERSISTENT RESERVE OUT command was
2227 		 * received, with the additional sense code set to
2228 		 * RESERVATIONS RELEASED.
2229 		 */
2230 		if (pr_holder &&
2231 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2232 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2233 			list_for_each_entry(pr_reg_p,
2234 					&pr_tmpl->registration_list,
2235 					pr_reg_list) {
2236 
2237 				target_ua_allocate_lun(
2238 					pr_reg_p->pr_reg_nacl,
2239 					pr_reg_p->pr_res_mapped_lun,
2240 					0x2A,
2241 					ASCQ_2AH_RESERVATIONS_RELEASED);
2242 			}
2243 		}
2244 
2245 		spin_unlock(&pr_tmpl->registration_lock);
2246 	}
2247 
2248 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2249 
2250 out:
2251 	if (pr_reg)
2252 		core_scsi3_put_pr_reg(pr_reg);
2253 	return ret;
2254 }
2255 
2256 unsigned char *core_scsi3_pr_dump_type(int type)
2257 {
2258 	switch (type) {
2259 	case PR_TYPE_WRITE_EXCLUSIVE:
2260 		return "Write Exclusive Access";
2261 	case PR_TYPE_EXCLUSIVE_ACCESS:
2262 		return "Exclusive Access";
2263 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2264 		return "Write Exclusive Access, Registrants Only";
2265 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2266 		return "Exclusive Access, Registrants Only";
2267 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2268 		return "Write Exclusive Access, All Registrants";
2269 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2270 		return "Exclusive Access, All Registrants";
2271 	default:
2272 		break;
2273 	}
2274 
2275 	return "Unknown SPC-3 PR Type";
2276 }
2277 
2278 static sense_reason_t
2279 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2280 {
2281 	struct se_device *dev = cmd->se_dev;
2282 	struct se_session *se_sess = cmd->se_sess;
2283 	struct se_lun *se_lun = cmd->se_lun;
2284 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2285 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2286 	char i_buf[PR_REG_ISID_ID_LEN];
2287 	sense_reason_t ret;
2288 
2289 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2290 
2291 	if (!se_sess || !se_lun) {
2292 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2293 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2294 	}
2295 	/*
2296 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2297 	 */
2298 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2299 				se_sess);
2300 	if (!pr_reg) {
2301 		pr_err("SPC-3 PR: Unable to locate"
2302 			" PR_REGISTERED *pr_reg for RESERVE\n");
2303 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2304 	}
2305 	/*
2306 	 * From spc4r17 Section 5.7.9: Reserving:
2307 	 *
2308 	 * An application client creates a persistent reservation by issuing
2309 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2310 	 * a registered I_T nexus with the following parameters:
2311 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2312 	 * 	 registered with the logical unit for the I_T nexus; and
2313 	 */
2314 	if (res_key != pr_reg->pr_res_key) {
2315 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2316 			" does not match existing SA REGISTER res_key:"
2317 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2318 		ret = TCM_RESERVATION_CONFLICT;
2319 		goto out_put_pr_reg;
2320 	}
2321 	/*
2322 	 * From spc4r17 Section 5.7.9: Reserving:
2323 	 *
2324 	 * From above:
2325 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2326 	 *     being created.
2327 	 *
2328 	 * Only one persistent reservation is allowed at a time per logical unit
2329 	 * and that persistent reservation has a scope of LU_SCOPE.
2330 	 */
2331 	if (scope != PR_SCOPE_LU_SCOPE) {
2332 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2333 		ret = TCM_INVALID_PARAMETER_LIST;
2334 		goto out_put_pr_reg;
2335 	}
2336 	/*
2337 	 * See if we have an existing PR reservation holder pointer at
2338 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2339 	 * *pr_res_holder.
2340 	 */
2341 	spin_lock(&dev->dev_reservation_lock);
2342 	pr_res_holder = dev->dev_pr_res_holder;
2343 	if (pr_res_holder) {
2344 		/*
2345 		 * From spc4r17 Section 5.7.9: Reserving:
2346 		 *
2347 		 * If the device server receives a PERSISTENT RESERVE OUT
2348 		 * command from an I_T nexus other than a persistent reservation
2349 		 * holder (see 5.7.10) that attempts to create a persistent
2350 		 * reservation when a persistent reservation already exists for
2351 		 * the logical unit, then the command shall be completed with
2352 		 * RESERVATION CONFLICT status.
2353 		 */
2354 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2355 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2356 			pr_err("SPC-3 PR: Attempted RESERVE from"
2357 				" [%s]: %s while reservation already held by"
2358 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2359 				cmd->se_tfo->get_fabric_name(),
2360 				se_sess->se_node_acl->initiatorname,
2361 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2362 				pr_res_holder->pr_reg_nacl->initiatorname);
2363 
2364 			spin_unlock(&dev->dev_reservation_lock);
2365 			ret = TCM_RESERVATION_CONFLICT;
2366 			goto out_put_pr_reg;
2367 		}
2368 		/*
2369 		 * From spc4r17 Section 5.7.9: Reserving:
2370 		 *
2371 		 * If a persistent reservation holder attempts to modify the
2372 		 * type or scope of an existing persistent reservation, the
2373 		 * command shall be completed with RESERVATION CONFLICT status.
2374 		 */
2375 		if ((pr_res_holder->pr_res_type != type) ||
2376 		    (pr_res_holder->pr_res_scope != scope)) {
2377 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2378 			pr_err("SPC-3 PR: Attempted RESERVE from"
2379 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2380 				" while reservation already held by [%s]: %s,"
2381 				" returning RESERVATION_CONFLICT\n",
2382 				cmd->se_tfo->get_fabric_name(),
2383 				se_sess->se_node_acl->initiatorname,
2384 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2385 				pr_res_holder->pr_reg_nacl->initiatorname);
2386 
2387 			spin_unlock(&dev->dev_reservation_lock);
2388 			ret = TCM_RESERVATION_CONFLICT;
2389 			goto out_put_pr_reg;
2390 		}
2391 		/*
2392 		 * From spc4r17 Section 5.7.9: Reserving:
2393 		 *
2394 		 * If the device server receives a PERSISTENT RESERVE OUT
2395 		 * command with RESERVE service action where the TYPE field and
2396 		 * the SCOPE field contain the same values as the existing type
2397 		 * and scope from a persistent reservation holder, it shall not
2398 		 * make any change to the existing persistent reservation and
2399 		 * shall completethe command with GOOD status.
2400 		 */
2401 		spin_unlock(&dev->dev_reservation_lock);
2402 		ret = 0;
2403 		goto out_put_pr_reg;
2404 	}
2405 	/*
2406 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2407 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2408 	 */
2409 	pr_reg->pr_res_scope = scope;
2410 	pr_reg->pr_res_type = type;
2411 	pr_reg->pr_res_holder = 1;
2412 	dev->dev_pr_res_holder = pr_reg;
2413 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2414 
2415 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2416 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2417 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2418 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2419 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2420 			cmd->se_tfo->get_fabric_name(),
2421 			se_sess->se_node_acl->initiatorname,
2422 			i_buf);
2423 	spin_unlock(&dev->dev_reservation_lock);
2424 
2425 	if (pr_tmpl->pr_aptpl_active)
2426 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2427 
2428 	ret = 0;
2429 out_put_pr_reg:
2430 	core_scsi3_put_pr_reg(pr_reg);
2431 	return ret;
2432 }
2433 
2434 static sense_reason_t
2435 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2436 		u64 res_key)
2437 {
2438 	switch (type) {
2439 	case PR_TYPE_WRITE_EXCLUSIVE:
2440 	case PR_TYPE_EXCLUSIVE_ACCESS:
2441 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2442 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2443 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2444 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2445 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2446 	default:
2447 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2448 			" 0x%02x\n", type);
2449 		return TCM_INVALID_CDB_FIELD;
2450 	}
2451 }
2452 
2453 /*
2454  * Called with struct se_device->dev_reservation_lock held.
2455  */
2456 static void __core_scsi3_complete_pro_release(
2457 	struct se_device *dev,
2458 	struct se_node_acl *se_nacl,
2459 	struct t10_pr_registration *pr_reg,
2460 	int explicit,
2461 	int unreg)
2462 {
2463 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2464 	char i_buf[PR_REG_ISID_ID_LEN];
2465 	int pr_res_type = 0, pr_res_scope = 0;
2466 
2467 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2468 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2469 	/*
2470 	 * Go ahead and release the current PR reservation holder.
2471 	 * If an All Registrants reservation is currently active and
2472 	 * a unregister operation is requested, replace the current
2473 	 * dev_pr_res_holder with another active registration.
2474 	 */
2475 	if (dev->dev_pr_res_holder) {
2476 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2477 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2478 		dev->dev_pr_res_holder->pr_res_type = 0;
2479 		dev->dev_pr_res_holder->pr_res_scope = 0;
2480 		dev->dev_pr_res_holder->pr_res_holder = 0;
2481 		dev->dev_pr_res_holder = NULL;
2482 	}
2483 	if (!unreg)
2484 		goto out;
2485 
2486 	spin_lock(&dev->t10_pr.registration_lock);
2487 	list_del_init(&pr_reg->pr_reg_list);
2488 	/*
2489 	 * If the I_T nexus is a reservation holder, the persistent reservation
2490 	 * is of an all registrants type, and the I_T nexus is the last remaining
2491 	 * registered I_T nexus, then the device server shall also release the
2492 	 * persistent reservation.
2493 	 */
2494 	if (!list_empty(&dev->t10_pr.registration_list) &&
2495 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2496 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2497 		dev->dev_pr_res_holder =
2498 			list_entry(dev->t10_pr.registration_list.next,
2499 				   struct t10_pr_registration, pr_reg_list);
2500 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2501 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2502 		dev->dev_pr_res_holder->pr_res_holder = 1;
2503 	}
2504 	spin_unlock(&dev->t10_pr.registration_lock);
2505 out:
2506 	if (!dev->dev_pr_res_holder) {
2507 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2508 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2509 			tfo->get_fabric_name(), (explicit) ? "explicit" :
2510 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2511 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2512 	}
2513 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2514 		tfo->get_fabric_name(), se_nacl->initiatorname,
2515 		i_buf);
2516 	/*
2517 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2518 	 */
2519 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2520 }
2521 
2522 static sense_reason_t
2523 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2524 		u64 res_key)
2525 {
2526 	struct se_device *dev = cmd->se_dev;
2527 	struct se_session *se_sess = cmd->se_sess;
2528 	struct se_lun *se_lun = cmd->se_lun;
2529 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2530 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2531 	sense_reason_t ret = 0;
2532 
2533 	if (!se_sess || !se_lun) {
2534 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2535 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2536 	}
2537 	/*
2538 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2539 	 */
2540 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2541 	if (!pr_reg) {
2542 		pr_err("SPC-3 PR: Unable to locate"
2543 			" PR_REGISTERED *pr_reg for RELEASE\n");
2544 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2545 	}
2546 	/*
2547 	 * From spc4r17 Section 5.7.11.2 Releasing:
2548 	 *
2549 	 * If there is no persistent reservation or in response to a persistent
2550 	 * reservation release request from a registered I_T nexus that is not a
2551 	 * persistent reservation holder (see 5.7.10), the device server shall
2552 	 * do the following:
2553 	 *
2554 	 *     a) Not release the persistent reservation, if any;
2555 	 *     b) Not remove any registrations; and
2556 	 *     c) Complete the command with GOOD status.
2557 	 */
2558 	spin_lock(&dev->dev_reservation_lock);
2559 	pr_res_holder = dev->dev_pr_res_holder;
2560 	if (!pr_res_holder) {
2561 		/*
2562 		 * No persistent reservation, return GOOD status.
2563 		 */
2564 		spin_unlock(&dev->dev_reservation_lock);
2565 		goto out_put_pr_reg;
2566 	}
2567 
2568 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2569 		/*
2570 		 * Release request from a registered I_T nexus that is not a
2571 		 * persistent reservation holder. return GOOD status.
2572 		 */
2573 		spin_unlock(&dev->dev_reservation_lock);
2574 		goto out_put_pr_reg;
2575 	}
2576 
2577 	/*
2578 	 * From spc4r17 Section 5.7.11.2 Releasing:
2579 	 *
2580 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2581 	 * release a persistent reservation.
2582 	 *
2583 	 * An application client releases the persistent reservation by issuing
2584 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2585 	 * an I_T nexus that is a persistent reservation holder with the
2586 	 * following parameters:
2587 	 *
2588 	 *     a) RESERVATION KEY field set to the value of the reservation key
2589 	 *	  that is registered with the logical unit for the I_T nexus;
2590 	 */
2591 	if (res_key != pr_reg->pr_res_key) {
2592 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2593 			" does not match existing SA REGISTER res_key:"
2594 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2595 		spin_unlock(&dev->dev_reservation_lock);
2596 		ret = TCM_RESERVATION_CONFLICT;
2597 		goto out_put_pr_reg;
2598 	}
2599 	/*
2600 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2601 	 *
2602 	 * b) TYPE field and SCOPE field set to match the persistent
2603 	 *    reservation being released.
2604 	 */
2605 	if ((pr_res_holder->pr_res_type != type) ||
2606 	    (pr_res_holder->pr_res_scope != scope)) {
2607 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2608 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2609 			" reservation from [%s]: %s with different TYPE "
2610 			"and/or SCOPE  while reservation already held by"
2611 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2612 			cmd->se_tfo->get_fabric_name(),
2613 			se_sess->se_node_acl->initiatorname,
2614 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2615 			pr_res_holder->pr_reg_nacl->initiatorname);
2616 
2617 		spin_unlock(&dev->dev_reservation_lock);
2618 		ret = TCM_RESERVATION_CONFLICT;
2619 		goto out_put_pr_reg;
2620 	}
2621 	/*
2622 	 * In response to a persistent reservation release request from the
2623 	 * persistent reservation holder the device server shall perform a
2624 	 * release by doing the following as an uninterrupted series of actions:
2625 	 * a) Release the persistent reservation;
2626 	 * b) Not remove any registration(s);
2627 	 * c) If the released persistent reservation is a registrants only type
2628 	 * or all registrants type persistent reservation,
2629 	 *    the device server shall establish a unit attention condition for
2630 	 *    the initiator port associated with every regis-
2631 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2632 	 *    RESERVE OUT command with RELEASE service action was received,
2633 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2634 	 * d) If the persistent reservation is of any other type, the device
2635 	 *    server shall not establish a unit attention condition.
2636 	 */
2637 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2638 					  pr_reg, 1, 0);
2639 
2640 	spin_unlock(&dev->dev_reservation_lock);
2641 
2642 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2643 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2644 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2645 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2646 		/*
2647 		 * If no UNIT ATTENTION conditions will be established for
2648 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2649 		 * go ahead and check for APTPL=1 update+write below
2650 		 */
2651 		goto write_aptpl;
2652 	}
2653 
2654 	spin_lock(&pr_tmpl->registration_lock);
2655 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2656 			pr_reg_list) {
2657 		/*
2658 		 * Do not establish a UNIT ATTENTION condition
2659 		 * for the calling I_T Nexus
2660 		 */
2661 		if (pr_reg_p == pr_reg)
2662 			continue;
2663 
2664 		target_ua_allocate_lun(pr_reg_p->pr_reg_nacl,
2665 				pr_reg_p->pr_res_mapped_lun,
2666 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2667 	}
2668 	spin_unlock(&pr_tmpl->registration_lock);
2669 
2670 write_aptpl:
2671 	if (pr_tmpl->pr_aptpl_active)
2672 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2673 
2674 out_put_pr_reg:
2675 	core_scsi3_put_pr_reg(pr_reg);
2676 	return ret;
2677 }
2678 
2679 static sense_reason_t
2680 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2681 {
2682 	struct se_device *dev = cmd->se_dev;
2683 	struct se_node_acl *pr_reg_nacl;
2684 	struct se_session *se_sess = cmd->se_sess;
2685 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2686 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2687 	u64 pr_res_mapped_lun = 0;
2688 	int calling_it_nexus = 0;
2689 	/*
2690 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2691 	 */
2692 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2693 			se_sess->se_node_acl, se_sess);
2694 	if (!pr_reg_n) {
2695 		pr_err("SPC-3 PR: Unable to locate"
2696 			" PR_REGISTERED *pr_reg for CLEAR\n");
2697 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2698 	}
2699 	/*
2700 	 * From spc4r17 section 5.7.11.6, Clearing:
2701 	 *
2702 	 * Any application client may release the persistent reservation and
2703 	 * remove all registrations from a device server by issuing a
2704 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2705 	 * registered I_T nexus with the following parameter:
2706 	 *
2707 	 *	a) RESERVATION KEY field set to the value of the reservation key
2708 	 * 	   that is registered with the logical unit for the I_T nexus.
2709 	 */
2710 	if (res_key != pr_reg_n->pr_res_key) {
2711 		pr_err("SPC-3 PR REGISTER: Received"
2712 			" res_key: 0x%016Lx does not match"
2713 			" existing SA REGISTER res_key:"
2714 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2715 		core_scsi3_put_pr_reg(pr_reg_n);
2716 		return TCM_RESERVATION_CONFLICT;
2717 	}
2718 	/*
2719 	 * a) Release the persistent reservation, if any;
2720 	 */
2721 	spin_lock(&dev->dev_reservation_lock);
2722 	pr_res_holder = dev->dev_pr_res_holder;
2723 	if (pr_res_holder) {
2724 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2725 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2726 						  pr_res_holder, 0, 0);
2727 	}
2728 	spin_unlock(&dev->dev_reservation_lock);
2729 	/*
2730 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2731 	 */
2732 	spin_lock(&pr_tmpl->registration_lock);
2733 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2734 			&pr_tmpl->registration_list, pr_reg_list) {
2735 
2736 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2737 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2738 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2739 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2740 					calling_it_nexus);
2741 		/*
2742 		 * e) Establish a unit attention condition for the initiator
2743 		 *    port associated with every registered I_T nexus other
2744 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2745 		 *    command with CLEAR service action was received, with the
2746 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2747 		 */
2748 		if (!calling_it_nexus)
2749 			target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun,
2750 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2751 	}
2752 	spin_unlock(&pr_tmpl->registration_lock);
2753 
2754 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2755 		cmd->se_tfo->get_fabric_name());
2756 
2757 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2758 
2759 	core_scsi3_pr_generation(dev);
2760 	return 0;
2761 }
2762 
2763 /*
2764  * Called with struct se_device->dev_reservation_lock held.
2765  */
2766 static void __core_scsi3_complete_pro_preempt(
2767 	struct se_device *dev,
2768 	struct t10_pr_registration *pr_reg,
2769 	struct list_head *preempt_and_abort_list,
2770 	int type,
2771 	int scope,
2772 	enum preempt_type preempt_type)
2773 {
2774 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2775 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2776 	char i_buf[PR_REG_ISID_ID_LEN];
2777 
2778 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2779 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2780 	/*
2781 	 * Do an implicit RELEASE of the existing reservation.
2782 	 */
2783 	if (dev->dev_pr_res_holder)
2784 		__core_scsi3_complete_pro_release(dev, nacl,
2785 						  dev->dev_pr_res_holder, 0, 0);
2786 
2787 	dev->dev_pr_res_holder = pr_reg;
2788 	pr_reg->pr_res_holder = 1;
2789 	pr_reg->pr_res_type = type;
2790 	pr_reg->pr_res_scope = scope;
2791 
2792 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2793 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2794 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2795 		core_scsi3_pr_dump_type(type),
2796 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2797 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2798 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2799 		nacl->initiatorname, i_buf);
2800 	/*
2801 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2802 	 * struct t10_pr_registration to the list that will be compared
2803 	 * against received CDBs..
2804 	 */
2805 	if (preempt_and_abort_list)
2806 		list_add_tail(&pr_reg->pr_reg_abort_list,
2807 				preempt_and_abort_list);
2808 }
2809 
2810 static void core_scsi3_release_preempt_and_abort(
2811 	struct list_head *preempt_and_abort_list,
2812 	struct t10_pr_registration *pr_reg_holder)
2813 {
2814 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2815 
2816 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2817 				pr_reg_abort_list) {
2818 
2819 		list_del(&pr_reg->pr_reg_abort_list);
2820 		if (pr_reg_holder == pr_reg)
2821 			continue;
2822 		if (pr_reg->pr_res_holder) {
2823 			pr_warn("pr_reg->pr_res_holder still set\n");
2824 			continue;
2825 		}
2826 
2827 		pr_reg->pr_reg_deve = NULL;
2828 		pr_reg->pr_reg_nacl = NULL;
2829 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2830 	}
2831 }
2832 
2833 static sense_reason_t
2834 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2835 		u64 sa_res_key, enum preempt_type preempt_type)
2836 {
2837 	struct se_device *dev = cmd->se_dev;
2838 	struct se_node_acl *pr_reg_nacl;
2839 	struct se_session *se_sess = cmd->se_sess;
2840 	LIST_HEAD(preempt_and_abort_list);
2841 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2842 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2843 	u64 pr_res_mapped_lun = 0;
2844 	int all_reg = 0, calling_it_nexus = 0;
2845 	bool sa_res_key_unmatched = sa_res_key != 0;
2846 	int prh_type = 0, prh_scope = 0;
2847 
2848 	if (!se_sess)
2849 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2850 
2851 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2852 				se_sess);
2853 	if (!pr_reg_n) {
2854 		pr_err("SPC-3 PR: Unable to locate"
2855 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2856 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2857 		return TCM_RESERVATION_CONFLICT;
2858 	}
2859 	if (pr_reg_n->pr_res_key != res_key) {
2860 		core_scsi3_put_pr_reg(pr_reg_n);
2861 		return TCM_RESERVATION_CONFLICT;
2862 	}
2863 	if (scope != PR_SCOPE_LU_SCOPE) {
2864 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2865 		core_scsi3_put_pr_reg(pr_reg_n);
2866 		return TCM_INVALID_PARAMETER_LIST;
2867 	}
2868 
2869 	spin_lock(&dev->dev_reservation_lock);
2870 	pr_res_holder = dev->dev_pr_res_holder;
2871 	if (pr_res_holder &&
2872 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2873 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2874 		all_reg = 1;
2875 
2876 	if (!all_reg && !sa_res_key) {
2877 		spin_unlock(&dev->dev_reservation_lock);
2878 		core_scsi3_put_pr_reg(pr_reg_n);
2879 		return TCM_INVALID_PARAMETER_LIST;
2880 	}
2881 	/*
2882 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2883 	 *
2884 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2885 	 * persistent reservation holder or there is no persistent reservation
2886 	 * holder (i.e., there is no persistent reservation), then the device
2887 	 * server shall perform a preempt by doing the following in an
2888 	 * uninterrupted series of actions. (See below..)
2889 	 */
2890 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2891 		/*
2892 		 * No existing or SA Reservation Key matching reservations..
2893 		 *
2894 		 * PROUT SA PREEMPT with All Registrant type reservations are
2895 		 * allowed to be processed without a matching SA Reservation Key
2896 		 */
2897 		spin_lock(&pr_tmpl->registration_lock);
2898 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2899 				&pr_tmpl->registration_list, pr_reg_list) {
2900 			/*
2901 			 * Removing of registrations in non all registrants
2902 			 * type reservations without a matching SA reservation
2903 			 * key.
2904 			 *
2905 			 * a) Remove the registrations for all I_T nexuses
2906 			 *    specified by the SERVICE ACTION RESERVATION KEY
2907 			 *    field;
2908 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2909 			 * c) Process tasks as defined in 5.7.1; and
2910 			 * d) Establish a unit attention condition for the
2911 			 *    initiator port associated with every I_T nexus
2912 			 *    that lost its registration other than the I_T
2913 			 *    nexus on which the PERSISTENT RESERVE OUT command
2914 			 *    was received, with the additional sense code set
2915 			 *    to REGISTRATIONS PREEMPTED.
2916 			 */
2917 			if (!all_reg) {
2918 				if (pr_reg->pr_res_key != sa_res_key)
2919 					continue;
2920 				sa_res_key_unmatched = false;
2921 
2922 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2923 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2924 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2925 				__core_scsi3_free_registration(dev, pr_reg,
2926 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2927 						NULL, calling_it_nexus);
2928 			} else {
2929 				/*
2930 				 * Case for any existing all registrants type
2931 				 * reservation, follow logic in spc4r17 section
2932 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2933 				 *
2934 				 * For a ZERO SA Reservation key, release
2935 				 * all other registrations and do an implicit
2936 				 * release of active persistent reservation.
2937 				 *
2938 				 * For a non-ZERO SA Reservation key, only
2939 				 * release the matching reservation key from
2940 				 * registrations.
2941 				 */
2942 				if ((sa_res_key) &&
2943 				     (pr_reg->pr_res_key != sa_res_key))
2944 					continue;
2945 				sa_res_key_unmatched = false;
2946 
2947 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2948 				if (calling_it_nexus)
2949 					continue;
2950 
2951 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2952 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2953 				__core_scsi3_free_registration(dev, pr_reg,
2954 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2955 						NULL, 0);
2956 			}
2957 			if (!calling_it_nexus)
2958 				target_ua_allocate_lun(pr_reg_nacl,
2959 					pr_res_mapped_lun, 0x2A,
2960 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2961 		}
2962 		spin_unlock(&pr_tmpl->registration_lock);
2963 		/*
2964 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2965 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2966 		 * RESERVATION KEY field to a value that does not match any
2967 		 * registered reservation key, then the device server shall
2968 		 * complete the command with RESERVATION CONFLICT status.
2969 		 */
2970 		if (sa_res_key_unmatched) {
2971 			spin_unlock(&dev->dev_reservation_lock);
2972 			core_scsi3_put_pr_reg(pr_reg_n);
2973 			return TCM_RESERVATION_CONFLICT;
2974 		}
2975 		/*
2976 		 * For an existing all registrants type reservation
2977 		 * with a zero SA rservation key, preempt the existing
2978 		 * reservation with the new PR type and scope.
2979 		 */
2980 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2981 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2982 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2983 				type, scope, preempt_type);
2984 
2985 			if (preempt_type == PREEMPT_AND_ABORT)
2986 				core_scsi3_release_preempt_and_abort(
2987 					&preempt_and_abort_list, pr_reg_n);
2988 		}
2989 		spin_unlock(&dev->dev_reservation_lock);
2990 
2991 		if (pr_tmpl->pr_aptpl_active)
2992 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2993 
2994 		core_scsi3_put_pr_reg(pr_reg_n);
2995 		core_scsi3_pr_generation(cmd->se_dev);
2996 		return 0;
2997 	}
2998 	/*
2999 	 * The PREEMPTing SA reservation key matches that of the
3000 	 * existing persistent reservation, first, we check if
3001 	 * we are preempting our own reservation.
3002 	 * From spc4r17, section 5.7.11.4.3 Preempting
3003 	 * persistent reservations and registration handling
3004 	 *
3005 	 * If an all registrants persistent reservation is not
3006 	 * present, it is not an error for the persistent
3007 	 * reservation holder to preempt itself (i.e., a
3008 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3009 	 * or a PREEMPT AND ABORT service action with the
3010 	 * SERVICE ACTION RESERVATION KEY value equal to the
3011 	 * persistent reservation holder's reservation key that
3012 	 * is received from the persistent reservation holder).
3013 	 * In that case, the device server shall establish the
3014 	 * new persistent reservation and maintain the
3015 	 * registration.
3016 	 */
3017 	prh_type = pr_res_holder->pr_res_type;
3018 	prh_scope = pr_res_holder->pr_res_scope;
3019 	/*
3020 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3021 	 * persistent reservation holder (see 5.7.10), the device
3022 	 * server shall perform a preempt by doing the following as
3023 	 * an uninterrupted series of actions:
3024 	 *
3025 	 * a) Release the persistent reservation for the holder
3026 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3027 	 */
3028 	if (pr_reg_n != pr_res_holder)
3029 		__core_scsi3_complete_pro_release(dev,
3030 						  pr_res_holder->pr_reg_nacl,
3031 						  dev->dev_pr_res_holder, 0, 0);
3032 	/*
3033 	 * b) Remove the registrations for all I_T nexuses identified
3034 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3035 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3036 	 *    OUT command. If an all registrants persistent reservation
3037 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3038 	 *    is set to zero, then all registrations shall be removed
3039 	 *    except for that of the I_T nexus that is being used for
3040 	 *    the PERSISTENT RESERVE OUT command;
3041 	 */
3042 	spin_lock(&pr_tmpl->registration_lock);
3043 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3044 			&pr_tmpl->registration_list, pr_reg_list) {
3045 
3046 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3047 		if (calling_it_nexus)
3048 			continue;
3049 
3050 		if (pr_reg->pr_res_key != sa_res_key)
3051 			continue;
3052 
3053 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3054 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3055 		__core_scsi3_free_registration(dev, pr_reg,
3056 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3057 				calling_it_nexus);
3058 		/*
3059 		 * e) Establish a unit attention condition for the initiator
3060 		 *    port associated with every I_T nexus that lost its
3061 		 *    persistent reservation and/or registration, with the
3062 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3063 		 */
3064 		target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3065 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3066 	}
3067 	spin_unlock(&pr_tmpl->registration_lock);
3068 	/*
3069 	 * c) Establish a persistent reservation for the preempting
3070 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3071 	 */
3072 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3073 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3074 			type, scope, preempt_type);
3075 	/*
3076 	 * d) Process tasks as defined in 5.7.1;
3077 	 * e) See above..
3078 	 * f) If the type or scope has changed, then for every I_T nexus
3079 	 *    whose reservation key was not removed, except for the I_T
3080 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3081 	 *    received, the device server shall establish a unit
3082 	 *    attention condition for the initiator port associated with
3083 	 *    that I_T nexus, with the additional sense code set to
3084 	 *    RESERVATIONS RELEASED. If the type or scope have not
3085 	 *    changed, then no unit attention condition(s) shall be
3086 	 *    established for this reason.
3087 	 */
3088 	if ((prh_type != type) || (prh_scope != scope)) {
3089 		spin_lock(&pr_tmpl->registration_lock);
3090 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3091 				&pr_tmpl->registration_list, pr_reg_list) {
3092 
3093 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3094 			if (calling_it_nexus)
3095 				continue;
3096 
3097 			target_ua_allocate_lun(pr_reg->pr_reg_nacl,
3098 					pr_reg->pr_res_mapped_lun, 0x2A,
3099 					ASCQ_2AH_RESERVATIONS_RELEASED);
3100 		}
3101 		spin_unlock(&pr_tmpl->registration_lock);
3102 	}
3103 	spin_unlock(&dev->dev_reservation_lock);
3104 	/*
3105 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3106 	 * All received CDBs for the matching existing reservation and
3107 	 * registrations undergo ABORT_TASK logic.
3108 	 *
3109 	 * From there, core_scsi3_release_preempt_and_abort() will
3110 	 * release every registration in the list (which have already
3111 	 * been removed from the primary pr_reg list), except the
3112 	 * new persistent reservation holder, the calling Initiator Port.
3113 	 */
3114 	if (preempt_type == PREEMPT_AND_ABORT) {
3115 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3116 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3117 						pr_reg_n);
3118 	}
3119 
3120 	if (pr_tmpl->pr_aptpl_active)
3121 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3122 
3123 	core_scsi3_put_pr_reg(pr_reg_n);
3124 	core_scsi3_pr_generation(cmd->se_dev);
3125 	return 0;
3126 }
3127 
3128 static sense_reason_t
3129 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3130 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3131 {
3132 	switch (type) {
3133 	case PR_TYPE_WRITE_EXCLUSIVE:
3134 	case PR_TYPE_EXCLUSIVE_ACCESS:
3135 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3136 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3137 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3138 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3139 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3140 					      sa_res_key, preempt_type);
3141 	default:
3142 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3143 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3144 		return TCM_INVALID_CDB_FIELD;
3145 	}
3146 }
3147 
3148 
3149 static sense_reason_t
3150 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3151 		u64 sa_res_key, int aptpl, int unreg)
3152 {
3153 	struct se_session *se_sess = cmd->se_sess;
3154 	struct se_device *dev = cmd->se_dev;
3155 	struct se_dev_entry *dest_se_deve = NULL;
3156 	struct se_lun *se_lun = cmd->se_lun, *tmp_lun;
3157 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3158 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3159 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3160 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3161 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3162 	unsigned char *buf;
3163 	const unsigned char *initiator_str;
3164 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
3165 	u32 tid_len, tmp_tid_len;
3166 	int new_reg = 0, type, scope, matching_iname;
3167 	sense_reason_t ret;
3168 	unsigned short rtpi;
3169 	unsigned char proto_ident;
3170 
3171 	if (!se_sess || !se_lun) {
3172 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3173 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3174 	}
3175 
3176 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3177 	se_tpg = se_sess->se_tpg;
3178 	tf_ops = se_tpg->se_tpg_tfo;
3179 	/*
3180 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3181 	 *	Register behaviors for a REGISTER AND MOVE service action
3182 	 *
3183 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3184 	 */
3185 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3186 				se_sess);
3187 	if (!pr_reg) {
3188 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3189 			" *pr_reg for REGISTER_AND_MOVE\n");
3190 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3191 	}
3192 	/*
3193 	 * The provided reservation key much match the existing reservation key
3194 	 * provided during this initiator's I_T nexus registration.
3195 	 */
3196 	if (res_key != pr_reg->pr_res_key) {
3197 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3198 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3199 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3200 		ret = TCM_RESERVATION_CONFLICT;
3201 		goto out_put_pr_reg;
3202 	}
3203 	/*
3204 	 * The service active reservation key needs to be non zero
3205 	 */
3206 	if (!sa_res_key) {
3207 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3208 			" sa_res_key\n");
3209 		ret = TCM_INVALID_PARAMETER_LIST;
3210 		goto out_put_pr_reg;
3211 	}
3212 
3213 	/*
3214 	 * Determine the Relative Target Port Identifier where the reservation
3215 	 * will be moved to for the TransportID containing SCSI initiator WWN
3216 	 * information.
3217 	 */
3218 	buf = transport_kmap_data_sg(cmd);
3219 	if (!buf) {
3220 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3221 		goto out_put_pr_reg;
3222 	}
3223 
3224 	rtpi = get_unaligned_be16(&buf[18]);
3225 	tid_len = get_unaligned_be32(&buf[20]);
3226 	transport_kunmap_data_sg(cmd);
3227 	buf = NULL;
3228 
3229 	if ((tid_len + 24) != cmd->data_length) {
3230 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3231 			" does not equal CDB data_length: %u\n", tid_len,
3232 			cmd->data_length);
3233 		ret = TCM_INVALID_PARAMETER_LIST;
3234 		goto out_put_pr_reg;
3235 	}
3236 
3237 	spin_lock(&dev->se_port_lock);
3238 	list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
3239 		if (tmp_lun->lun_rtpi != rtpi)
3240 			continue;
3241 		dest_se_tpg = tmp_lun->lun_tpg;
3242 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3243 		if (!dest_tf_ops)
3244 			continue;
3245 
3246 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3247 		spin_unlock(&dev->se_port_lock);
3248 
3249 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3250 			pr_err("core_scsi3_tpg_depend_item() failed"
3251 				" for dest_se_tpg\n");
3252 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3253 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3254 			goto out_put_pr_reg;
3255 		}
3256 
3257 		spin_lock(&dev->se_port_lock);
3258 		break;
3259 	}
3260 	spin_unlock(&dev->se_port_lock);
3261 
3262 	if (!dest_se_tpg || !dest_tf_ops) {
3263 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3264 			" fabric ops from Relative Target Port Identifier:"
3265 			" %hu\n", rtpi);
3266 		ret = TCM_INVALID_PARAMETER_LIST;
3267 		goto out_put_pr_reg;
3268 	}
3269 
3270 	buf = transport_kmap_data_sg(cmd);
3271 	if (!buf) {
3272 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3273 		goto out_put_pr_reg;
3274 	}
3275 	proto_ident = (buf[24] & 0x0f);
3276 
3277 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3278 			" 0x%02x\n", proto_ident);
3279 
3280 	if (proto_ident != dest_se_tpg->proto_id) {
3281 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3282 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3283 			" from fabric: %s\n", proto_ident,
3284 			dest_se_tpg->proto_id,
3285 			dest_tf_ops->get_fabric_name());
3286 		ret = TCM_INVALID_PARAMETER_LIST;
3287 		goto out;
3288 	}
3289 	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
3290 			&buf[24], &tmp_tid_len, &iport_ptr);
3291 	if (!initiator_str) {
3292 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3293 			" initiator_str from Transport ID\n");
3294 		ret = TCM_INVALID_PARAMETER_LIST;
3295 		goto out;
3296 	}
3297 
3298 	transport_kunmap_data_sg(cmd);
3299 	buf = NULL;
3300 
3301 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3302 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3303 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3304 		iport_ptr : "");
3305 	/*
3306 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3307 	 * action specifies a TransportID that is the same as the initiator port
3308 	 * of the I_T nexus for the command received, then the command shall
3309 	 * be terminated with CHECK CONDITION status, with the sense key set to
3310 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3311 	 * IN PARAMETER LIST.
3312 	 */
3313 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3314 	matching_iname = (!strcmp(initiator_str,
3315 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3316 	if (!matching_iname)
3317 		goto after_iport_check;
3318 
3319 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3320 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3321 			" matches: %s on received I_T Nexus\n", initiator_str,
3322 			pr_reg_nacl->initiatorname);
3323 		ret = TCM_INVALID_PARAMETER_LIST;
3324 		goto out;
3325 	}
3326 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3327 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3328 			" matches: %s %s on received I_T Nexus\n",
3329 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3330 			pr_reg->pr_reg_isid);
3331 		ret = TCM_INVALID_PARAMETER_LIST;
3332 		goto out;
3333 	}
3334 after_iport_check:
3335 	/*
3336 	 * Locate the destination struct se_node_acl from the received Transport ID
3337 	 */
3338 	mutex_lock(&dest_se_tpg->acl_node_mutex);
3339 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3340 				initiator_str);
3341 	if (dest_node_acl)
3342 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3343 	mutex_unlock(&dest_se_tpg->acl_node_mutex);
3344 
3345 	if (!dest_node_acl) {
3346 		pr_err("Unable to locate %s dest_node_acl for"
3347 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3348 			initiator_str);
3349 		ret = TCM_INVALID_PARAMETER_LIST;
3350 		goto out;
3351 	}
3352 
3353 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3354 		pr_err("core_scsi3_nodeacl_depend_item() for"
3355 			" dest_node_acl\n");
3356 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3357 		dest_node_acl = NULL;
3358 		ret = TCM_INVALID_PARAMETER_LIST;
3359 		goto out;
3360 	}
3361 
3362 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3363 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3364 		dest_node_acl->initiatorname);
3365 
3366 	/*
3367 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3368 	 * PORT IDENTIFIER.
3369 	 */
3370 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3371 	if (!dest_se_deve) {
3372 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3373 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3374 		ret = TCM_INVALID_PARAMETER_LIST;
3375 		goto out;
3376 	}
3377 
3378 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3379 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3380 		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
3381 		dest_se_deve = NULL;
3382 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3383 		goto out;
3384 	}
3385 
3386 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3387 		" ACL for dest_se_deve->mapped_lun: %llu\n",
3388 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3389 		dest_se_deve->mapped_lun);
3390 
3391 	/*
3392 	 * A persistent reservation needs to already existing in order to
3393 	 * successfully complete the REGISTER_AND_MOVE service action..
3394 	 */
3395 	spin_lock(&dev->dev_reservation_lock);
3396 	pr_res_holder = dev->dev_pr_res_holder;
3397 	if (!pr_res_holder) {
3398 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3399 			" currently held\n");
3400 		spin_unlock(&dev->dev_reservation_lock);
3401 		ret = TCM_INVALID_CDB_FIELD;
3402 		goto out;
3403 	}
3404 	/*
3405 	 * The received on I_T Nexus must be the reservation holder.
3406 	 *
3407 	 * From spc4r17 section 5.7.8  Table 50 --
3408 	 * 	Register behaviors for a REGISTER AND MOVE service action
3409 	 */
3410 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3411 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3412 			" Nexus is not reservation holder\n");
3413 		spin_unlock(&dev->dev_reservation_lock);
3414 		ret = TCM_RESERVATION_CONFLICT;
3415 		goto out;
3416 	}
3417 	/*
3418 	 * From spc4r17 section 5.7.8: registering and moving reservation
3419 	 *
3420 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3421 	 * action is received and the established persistent reservation is a
3422 	 * Write Exclusive - All Registrants type or Exclusive Access -
3423 	 * All Registrants type reservation, then the command shall be completed
3424 	 * with RESERVATION CONFLICT status.
3425 	 */
3426 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3427 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3428 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3429 			" reservation for type: %s\n",
3430 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3431 		spin_unlock(&dev->dev_reservation_lock);
3432 		ret = TCM_RESERVATION_CONFLICT;
3433 		goto out;
3434 	}
3435 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3436 	/*
3437 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3438 	 */
3439 	type = pr_res_holder->pr_res_type;
3440 	scope = pr_res_holder->pr_res_type;
3441 	/*
3442 	 * c) Associate the reservation key specified in the SERVICE ACTION
3443 	 *    RESERVATION KEY field with the I_T nexus specified as the
3444 	 *    destination of the register and move, where:
3445 	 *    A) The I_T nexus is specified by the TransportID and the
3446 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3447 	 *    B) Regardless of the TransportID format used, the association for
3448 	 *       the initiator port is based on either the initiator port name
3449 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3450 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3451 	 *       transport protocols where port names are not required;
3452 	 * d) Register the reservation key specified in the SERVICE ACTION
3453 	 *    RESERVATION KEY field;
3454 	 * e) Retain the reservation key specified in the SERVICE ACTION
3455 	 *    RESERVATION KEY field and associated information;
3456 	 *
3457 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3458 	 * register an I_T nexus that is already registered with the same
3459 	 * reservation key or a different reservation key.
3460 	 */
3461 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3462 					iport_ptr);
3463 	if (!dest_pr_reg) {
3464 		struct se_lun *dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
3465 				kref_read(&dest_se_deve->pr_kref) != 0);
3466 
3467 		spin_unlock(&dev->dev_reservation_lock);
3468 		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
3469 					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
3470 					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
3471 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3472 			goto out;
3473 		}
3474 		spin_lock(&dev->dev_reservation_lock);
3475 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3476 						iport_ptr);
3477 		new_reg = 1;
3478 	}
3479 	/*
3480 	 * f) Release the persistent reservation for the persistent reservation
3481 	 *    holder (i.e., the I_T nexus on which the
3482 	 */
3483 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3484 					  dev->dev_pr_res_holder, 0, 0);
3485 	/*
3486 	 * g) Move the persistent reservation to the specified I_T nexus using
3487 	 *    the same scope and type as the persistent reservation released in
3488 	 *    item f); and
3489 	 */
3490 	dev->dev_pr_res_holder = dest_pr_reg;
3491 	dest_pr_reg->pr_res_holder = 1;
3492 	dest_pr_reg->pr_res_type = type;
3493 	pr_reg->pr_res_scope = scope;
3494 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3495 	/*
3496 	 * Increment PRGeneration for existing registrations..
3497 	 */
3498 	if (!new_reg)
3499 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3500 	spin_unlock(&dev->dev_reservation_lock);
3501 
3502 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3503 		" created new reservation holder TYPE: %s on object RTPI:"
3504 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3505 		core_scsi3_pr_dump_type(type), rtpi,
3506 		dest_pr_reg->pr_res_generation);
3507 	pr_debug("SPC-3 PR Successfully moved reservation from"
3508 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3509 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3510 		i_buf, dest_tf_ops->get_fabric_name(),
3511 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3512 		iport_ptr : "");
3513 	/*
3514 	 * It is now safe to release configfs group dependencies for destination
3515 	 * of Transport ID Initiator Device/Port Identifier
3516 	 */
3517 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3518 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3519 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3520 	/*
3521 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3522 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3523 	 */
3524 	if (unreg) {
3525 		spin_lock(&pr_tmpl->registration_lock);
3526 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3527 		spin_unlock(&pr_tmpl->registration_lock);
3528 	} else
3529 		core_scsi3_put_pr_reg(pr_reg);
3530 
3531 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3532 
3533 	core_scsi3_put_pr_reg(dest_pr_reg);
3534 	return 0;
3535 out:
3536 	if (buf)
3537 		transport_kunmap_data_sg(cmd);
3538 	if (dest_se_deve)
3539 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3540 	if (dest_node_acl)
3541 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3542 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3543 
3544 out_put_pr_reg:
3545 	core_scsi3_put_pr_reg(pr_reg);
3546 	return ret;
3547 }
3548 
3549 /*
3550  * See spc4r17 section 6.14 Table 170
3551  */
3552 sense_reason_t
3553 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3554 {
3555 	struct se_device *dev = cmd->se_dev;
3556 	unsigned char *cdb = &cmd->t_task_cdb[0];
3557 	unsigned char *buf;
3558 	u64 res_key, sa_res_key;
3559 	int sa, scope, type, aptpl;
3560 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3561 	sense_reason_t ret;
3562 
3563 	/*
3564 	 * Following spc2r20 5.5.1 Reservations overview:
3565 	 *
3566 	 * If a logical unit has been reserved by any RESERVE command and is
3567 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3568 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3569 	 * initiator or service action and shall terminate with a RESERVATION
3570 	 * CONFLICT status.
3571 	 */
3572 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3573 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3574 			" SPC-2 reservation is held, returning"
3575 			" RESERVATION_CONFLICT\n");
3576 		return TCM_RESERVATION_CONFLICT;
3577 	}
3578 
3579 	/*
3580 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3581 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3582 	 */
3583 	if (!cmd->se_sess)
3584 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3585 
3586 	if (cmd->data_length < 24) {
3587 		pr_warn("SPC-PR: Received PR OUT parameter list"
3588 			" length too small: %u\n", cmd->data_length);
3589 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3590 	}
3591 
3592 	/*
3593 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3594 	 */
3595 	sa = (cdb[1] & 0x1f);
3596 	scope = (cdb[2] & 0xf0);
3597 	type = (cdb[2] & 0x0f);
3598 
3599 	buf = transport_kmap_data_sg(cmd);
3600 	if (!buf)
3601 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3602 
3603 	/*
3604 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3605 	 */
3606 	res_key = get_unaligned_be64(&buf[0]);
3607 	sa_res_key = get_unaligned_be64(&buf[8]);
3608 	/*
3609 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3610 	 * SCSI TransportIDs.
3611 	 */
3612 	if (sa != PRO_REGISTER_AND_MOVE) {
3613 		spec_i_pt = (buf[20] & 0x08);
3614 		all_tg_pt = (buf[20] & 0x04);
3615 		aptpl = (buf[20] & 0x01);
3616 	} else {
3617 		aptpl = (buf[17] & 0x01);
3618 		unreg = (buf[17] & 0x02);
3619 	}
3620 	/*
3621 	 * If the backend device has been configured to force APTPL metadata
3622 	 * write-out, go ahead and propigate aptpl=1 down now.
3623 	 */
3624 	if (dev->dev_attrib.force_pr_aptpl)
3625 		aptpl = 1;
3626 
3627 	transport_kunmap_data_sg(cmd);
3628 	buf = NULL;
3629 
3630 	/*
3631 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3632 	 */
3633 	if (spec_i_pt && (sa != PRO_REGISTER))
3634 		return TCM_INVALID_PARAMETER_LIST;
3635 
3636 	/*
3637 	 * From spc4r17 section 6.14:
3638 	 *
3639 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3640 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3641 	 * the command shall be terminated with CHECK CONDITION status, with
3642 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3643 	 * code set to PARAMETER LIST LENGTH ERROR.
3644 	 */
3645 	if (!spec_i_pt && (sa != PRO_REGISTER_AND_MOVE) &&
3646 	    (cmd->data_length != 24)) {
3647 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3648 			" list length: %u\n", cmd->data_length);
3649 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3650 	}
3651 
3652 	/*
3653 	 * (core_scsi3_emulate_pro_* function parameters
3654 	 * are defined by spc4r17 Table 174:
3655 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3656 	 */
3657 	switch (sa) {
3658 	case PRO_REGISTER:
3659 		ret = core_scsi3_emulate_pro_register(cmd,
3660 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3661 		break;
3662 	case PRO_RESERVE:
3663 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3664 		break;
3665 	case PRO_RELEASE:
3666 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3667 		break;
3668 	case PRO_CLEAR:
3669 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3670 		break;
3671 	case PRO_PREEMPT:
3672 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3673 					res_key, sa_res_key, PREEMPT);
3674 		break;
3675 	case PRO_PREEMPT_AND_ABORT:
3676 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3677 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3678 		break;
3679 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3680 		ret = core_scsi3_emulate_pro_register(cmd,
3681 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3682 		break;
3683 	case PRO_REGISTER_AND_MOVE:
3684 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3685 				sa_res_key, aptpl, unreg);
3686 		break;
3687 	default:
3688 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3689 			" action: 0x%02x\n", sa);
3690 		return TCM_INVALID_CDB_FIELD;
3691 	}
3692 
3693 	if (!ret)
3694 		target_complete_cmd(cmd, GOOD);
3695 	return ret;
3696 }
3697 
3698 /*
3699  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3700  *
3701  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3702  */
3703 static sense_reason_t
3704 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3705 {
3706 	struct se_device *dev = cmd->se_dev;
3707 	struct t10_pr_registration *pr_reg;
3708 	unsigned char *buf;
3709 	u32 add_len = 0, off = 8;
3710 
3711 	if (cmd->data_length < 8) {
3712 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3713 			" too small\n", cmd->data_length);
3714 		return TCM_INVALID_CDB_FIELD;
3715 	}
3716 
3717 	buf = transport_kmap_data_sg(cmd);
3718 	if (!buf)
3719 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3720 
3721 	put_unaligned_be32(dev->t10_pr.pr_generation, buf);
3722 
3723 	spin_lock(&dev->t10_pr.registration_lock);
3724 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3725 			pr_reg_list) {
3726 		/*
3727 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3728 		 * next reservation key list descriptor.
3729 		 */
3730 		if ((add_len + 8) > (cmd->data_length - 8))
3731 			break;
3732 
3733 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3734 		off += 8;
3735 		add_len += 8;
3736 	}
3737 	spin_unlock(&dev->t10_pr.registration_lock);
3738 
3739 	put_unaligned_be32(add_len, &buf[4]);
3740 
3741 	transport_kunmap_data_sg(cmd);
3742 
3743 	return 0;
3744 }
3745 
3746 /*
3747  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3748  *
3749  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3750  */
3751 static sense_reason_t
3752 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3753 {
3754 	struct se_device *dev = cmd->se_dev;
3755 	struct t10_pr_registration *pr_reg;
3756 	unsigned char *buf;
3757 	u64 pr_res_key;
3758 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3759 
3760 	if (cmd->data_length < 8) {
3761 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3762 			" too small\n", cmd->data_length);
3763 		return TCM_INVALID_CDB_FIELD;
3764 	}
3765 
3766 	buf = transport_kmap_data_sg(cmd);
3767 	if (!buf)
3768 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3769 
3770 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3771 
3772 	spin_lock(&dev->dev_reservation_lock);
3773 	pr_reg = dev->dev_pr_res_holder;
3774 	if (pr_reg) {
3775 		/*
3776 		 * Set the hardcoded Additional Length
3777 		 */
3778 		put_unaligned_be32(add_len, &buf[4]);
3779 
3780 		if (cmd->data_length < 22)
3781 			goto err;
3782 
3783 		/*
3784 		 * Set the Reservation key.
3785 		 *
3786 		 * From spc4r17, section 5.7.10:
3787 		 * A persistent reservation holder has its reservation key
3788 		 * returned in the parameter data from a PERSISTENT
3789 		 * RESERVE IN command with READ RESERVATION service action as
3790 		 * follows:
3791 		 * a) For a persistent reservation of the type Write Exclusive
3792 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3793 		 *      the reservation key shall be set to zero; or
3794 		 * b) For all other persistent reservation types, the
3795 		 *    reservation key shall be set to the registered
3796 		 *    reservation key for the I_T nexus that holds the
3797 		 *    persistent reservation.
3798 		 */
3799 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3800 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3801 			pr_res_key = 0;
3802 		else
3803 			pr_res_key = pr_reg->pr_res_key;
3804 
3805 		put_unaligned_be64(pr_res_key, &buf[8]);
3806 		/*
3807 		 * Set the SCOPE and TYPE
3808 		 */
3809 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3810 			  (pr_reg->pr_res_type & 0x0f);
3811 	}
3812 
3813 err:
3814 	spin_unlock(&dev->dev_reservation_lock);
3815 	transport_kunmap_data_sg(cmd);
3816 
3817 	return 0;
3818 }
3819 
3820 /*
3821  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3822  *
3823  * See spc4r17 section 6.13.4 Table 165
3824  */
3825 static sense_reason_t
3826 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3827 {
3828 	struct se_device *dev = cmd->se_dev;
3829 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3830 	unsigned char *buf;
3831 	u16 add_len = 8; /* Hardcoded to 8. */
3832 
3833 	if (cmd->data_length < 6) {
3834 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3835 			" %u too small\n", cmd->data_length);
3836 		return TCM_INVALID_CDB_FIELD;
3837 	}
3838 
3839 	buf = transport_kmap_data_sg(cmd);
3840 	if (!buf)
3841 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3842 
3843 	put_unaligned_be16(add_len, &buf[0]);
3844 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3845 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3846 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3847 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3848 	/*
3849 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3850 	 * set the TMV: Task Mask Valid bit.
3851 	 */
3852 	buf[3] |= 0x80;
3853 	/*
3854 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3855 	 */
3856 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3857 	/*
3858 	 * PTPL_A: Persistence across Target Power Loss Active bit
3859 	 */
3860 	if (pr_tmpl->pr_aptpl_active)
3861 		buf[3] |= 0x01;
3862 	/*
3863 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3864 	 */
3865 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3866 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3867 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3868 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3869 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3870 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3871 
3872 	transport_kunmap_data_sg(cmd);
3873 
3874 	return 0;
3875 }
3876 
3877 /*
3878  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3879  *
3880  * See spc4r17 section 6.13.5 Table 168 and 169
3881  */
3882 static sense_reason_t
3883 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3884 {
3885 	struct se_device *dev = cmd->se_dev;
3886 	struct se_node_acl *se_nacl;
3887 	struct se_portal_group *se_tpg;
3888 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3889 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3890 	unsigned char *buf;
3891 	u32 add_desc_len = 0, add_len = 0;
3892 	u32 off = 8; /* off into first Full Status descriptor */
3893 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3894 	int exp_desc_len, desc_len;
3895 	bool all_reg = false;
3896 
3897 	if (cmd->data_length < 8) {
3898 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3899 			" too small\n", cmd->data_length);
3900 		return TCM_INVALID_CDB_FIELD;
3901 	}
3902 
3903 	buf = transport_kmap_data_sg(cmd);
3904 	if (!buf)
3905 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3906 
3907 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3908 
3909 	spin_lock(&dev->dev_reservation_lock);
3910 	if (dev->dev_pr_res_holder) {
3911 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3912 
3913 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3914 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3915 			all_reg = true;
3916 			pr_res_type = pr_holder->pr_res_type;
3917 			pr_res_scope = pr_holder->pr_res_scope;
3918 		}
3919 	}
3920 	spin_unlock(&dev->dev_reservation_lock);
3921 
3922 	spin_lock(&pr_tmpl->registration_lock);
3923 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3924 			&pr_tmpl->registration_list, pr_reg_list) {
3925 
3926 		se_nacl = pr_reg->pr_reg_nacl;
3927 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3928 		add_desc_len = 0;
3929 
3930 		atomic_inc_mb(&pr_reg->pr_res_holders);
3931 		spin_unlock(&pr_tmpl->registration_lock);
3932 		/*
3933 		 * Determine expected length of $FABRIC_MOD specific
3934 		 * TransportID full status descriptor..
3935 		 */
3936 		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
3937 					&format_code);
3938 		if (exp_desc_len < 0 ||
3939 		    exp_desc_len + add_len > cmd->data_length) {
3940 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3941 				" out of buffer: %d\n", cmd->data_length);
3942 			spin_lock(&pr_tmpl->registration_lock);
3943 			atomic_dec_mb(&pr_reg->pr_res_holders);
3944 			break;
3945 		}
3946 		/*
3947 		 * Set RESERVATION KEY
3948 		 */
3949 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3950 		off += 8;
3951 		off += 4; /* Skip Over Reserved area */
3952 
3953 		/*
3954 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3955 		 */
3956 		if (pr_reg->pr_reg_all_tg_pt)
3957 			buf[off] = 0x02;
3958 		/*
3959 		 * The struct se_lun pointer will be present for the
3960 		 * reservation holder for PR_HOLDER bit.
3961 		 *
3962 		 * Also, if this registration is the reservation
3963 		 * holder or there is an All Registrants reservation
3964 		 * active, fill in SCOPE and TYPE in the next byte.
3965 		 */
3966 		if (pr_reg->pr_res_holder) {
3967 			buf[off++] |= 0x01;
3968 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3969 				     (pr_reg->pr_res_type & 0x0f);
3970 		} else if (all_reg) {
3971 			buf[off++] |= 0x01;
3972 			buf[off++] = (pr_res_scope & 0xf0) |
3973 				     (pr_res_type & 0x0f);
3974 		} else {
3975 			off += 2;
3976 		}
3977 
3978 		off += 4; /* Skip over reserved area */
3979 		/*
3980 		 * From spc4r17 6.3.15:
3981 		 *
3982 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
3983 		 * IDENTIFIER field contains the relative port identifier (see
3984 		 * 3.1.120) of the target port that is part of the I_T nexus
3985 		 * described by this full status descriptor. If the ALL_TG_PT
3986 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
3987 		 * IDENTIFIER field are not defined by this standard.
3988 		 */
3989 		if (!pr_reg->pr_reg_all_tg_pt) {
3990 			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;
3991 
3992 			put_unaligned_be16(sep_rtpi, &buf[off]);
3993 			off += 2;
3994 		} else
3995 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
3996 
3997 		buf[off+4] = se_tpg->proto_id;
3998 
3999 		/*
4000 		 * Now, have the $FABRIC_MOD fill in the transport ID.
4001 		 */
4002 		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
4003 				&format_code, &buf[off+4]);
4004 
4005 		spin_lock(&pr_tmpl->registration_lock);
4006 		atomic_dec_mb(&pr_reg->pr_res_holders);
4007 
4008 		if (desc_len < 0)
4009 			break;
4010 		/*
4011 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4012 		 */
4013 		put_unaligned_be32(desc_len, &buf[off]);
4014 		off += 4;
4015 		/*
4016 		 * Size of full desctipor header minus TransportID
4017 		 * containing $FABRIC_MOD specific) initiator device/port
4018 		 * WWN information.
4019 		 *
4020 		 *  See spc4r17 Section 6.13.5 Table 169
4021 		 */
4022 		add_desc_len = (24 + desc_len);
4023 
4024 		off += desc_len;
4025 		add_len += add_desc_len;
4026 	}
4027 	spin_unlock(&pr_tmpl->registration_lock);
4028 	/*
4029 	 * Set ADDITIONAL_LENGTH
4030 	 */
4031 	put_unaligned_be32(add_len, &buf[4]);
4032 
4033 	transport_kunmap_data_sg(cmd);
4034 
4035 	return 0;
4036 }
4037 
4038 sense_reason_t
4039 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4040 {
4041 	sense_reason_t ret;
4042 
4043 	/*
4044 	 * Following spc2r20 5.5.1 Reservations overview:
4045 	 *
4046 	 * If a logical unit has been reserved by any RESERVE command and is
4047 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4048 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4049 	 * initiator or service action and shall terminate with a RESERVATION
4050 	 * CONFLICT status.
4051 	 */
4052 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4053 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4054 			" SPC-2 reservation is held, returning"
4055 			" RESERVATION_CONFLICT\n");
4056 		return TCM_RESERVATION_CONFLICT;
4057 	}
4058 
4059 	switch (cmd->t_task_cdb[1] & 0x1f) {
4060 	case PRI_READ_KEYS:
4061 		ret = core_scsi3_pri_read_keys(cmd);
4062 		break;
4063 	case PRI_READ_RESERVATION:
4064 		ret = core_scsi3_pri_read_reservation(cmd);
4065 		break;
4066 	case PRI_REPORT_CAPABILITIES:
4067 		ret = core_scsi3_pri_report_capabilities(cmd);
4068 		break;
4069 	case PRI_READ_FULL_STATUS:
4070 		ret = core_scsi3_pri_read_full_status(cmd);
4071 		break;
4072 	default:
4073 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4074 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4075 		return TCM_INVALID_CDB_FIELD;
4076 	}
4077 
4078 	if (!ret)
4079 		target_complete_cmd(cmd, GOOD);
4080 	return ret;
4081 }
4082 
4083 sense_reason_t
4084 target_check_reservation(struct se_cmd *cmd)
4085 {
4086 	struct se_device *dev = cmd->se_dev;
4087 	sense_reason_t ret;
4088 
4089 	if (!cmd->se_sess)
4090 		return 0;
4091 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4092 		return 0;
4093 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
4094 		return 0;
4095 
4096 	spin_lock(&dev->dev_reservation_lock);
4097 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4098 		ret = target_scsi2_reservation_check(cmd);
4099 	else
4100 		ret = target_scsi3_pr_reservation_check(cmd);
4101 	spin_unlock(&dev->dev_reservation_lock);
4102 
4103 	return ret;
4104 }
4105