1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename:  target_core_pr.c
4  *
5  * This file contains SPC-3 compliant persistent reservations and
6  * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
7  *
8  * (c) Copyright 2009-2013 Datera, Inc.
9  *
10  * Nicholas A. Bellinger <nab@kernel.org>
11  *
12  ******************************************************************************/
13 
14 #include <linux/slab.h>
15 #include <linux/spinlock.h>
16 #include <linux/list.h>
17 #include <linux/vmalloc.h>
18 #include <linux/file.h>
19 #include <linux/fcntl.h>
20 #include <linux/fs.h>
21 #include <scsi/scsi_proto.h>
22 #include <asm/unaligned.h>
23 
24 #include <target/target_core_base.h>
25 #include <target/target_core_backend.h>
26 #include <target/target_core_fabric.h>
27 
28 #include "target_core_internal.h"
29 #include "target_core_pr.h"
30 #include "target_core_ua.h"
31 
32 /*
33  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
34  */
35 struct pr_transport_id_holder {
36 	struct t10_pr_registration *dest_pr_reg;
37 	struct se_portal_group *dest_tpg;
38 	struct se_node_acl *dest_node_acl;
39 	struct se_dev_entry *dest_se_deve;
40 	struct list_head dest_list;
41 };
42 
43 void core_pr_dump_initiator_port(
44 	struct t10_pr_registration *pr_reg,
45 	char *buf,
46 	u32 size)
47 {
48 	if (!pr_reg->isid_present_at_reg) {
49 		buf[0] = '\0';
50 		return;
51 	}
52 
53 	snprintf(buf, size, ",i,0x%s", pr_reg->pr_reg_isid);
54 }
55 
56 enum register_type {
57 	REGISTER,
58 	REGISTER_AND_IGNORE_EXISTING_KEY,
59 	REGISTER_AND_MOVE,
60 };
61 
62 enum preempt_type {
63 	PREEMPT,
64 	PREEMPT_AND_ABORT,
65 };
66 
67 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
68 					      struct t10_pr_registration *, int, int);
69 
70 static int is_reservation_holder(
71 	struct t10_pr_registration *pr_res_holder,
72 	struct t10_pr_registration *pr_reg)
73 {
74 	int pr_res_type;
75 
76 	if (pr_res_holder) {
77 		pr_res_type = pr_res_holder->pr_res_type;
78 
79 		return pr_res_holder == pr_reg ||
80 		       pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
81 		       pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG;
82 	}
83 	return 0;
84 }
85 
86 static sense_reason_t
87 target_scsi2_reservation_check(struct se_cmd *cmd)
88 {
89 	struct se_device *dev = cmd->se_dev;
90 	struct se_session *sess = cmd->se_sess;
91 
92 	switch (cmd->t_task_cdb[0]) {
93 	case INQUIRY:
94 	case RELEASE:
95 	case RELEASE_10:
96 		return 0;
97 	default:
98 		break;
99 	}
100 
101 	if (!dev->reservation_holder || !sess)
102 		return 0;
103 
104 	if (dev->reservation_holder->se_node_acl != sess->se_node_acl)
105 		return TCM_RESERVATION_CONFLICT;
106 
107 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
108 		if (dev->dev_res_bin_isid != sess->sess_bin_isid)
109 			return TCM_RESERVATION_CONFLICT;
110 	}
111 
112 	return 0;
113 }
114 
115 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
116 					struct se_node_acl *, struct se_session *);
117 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
118 
119 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
120 {
121 	struct se_session *se_sess = cmd->se_sess;
122 	struct se_device *dev = cmd->se_dev;
123 	struct t10_pr_registration *pr_reg;
124 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
125 	int conflict = 0;
126 
127 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
128 			se_sess);
129 	if (pr_reg) {
130 		/*
131 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
132 		 * behavior
133 		 *
134 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
135 		 * status, but no reservation shall be established and the
136 		 * persistent reservation shall not be changed, if the command
137 		 * is received from a) and b) below.
138 		 *
139 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
140 		 * status, but the persistent reservation shall not be released,
141 		 * if the command is received from a) and b)
142 		 *
143 		 * a) An I_T nexus that is a persistent reservation holder; or
144 		 * b) An I_T nexus that is registered if a registrants only or
145 		 *    all registrants type persistent reservation is present.
146 		 *
147 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
148 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
149 		 * as defined in SPC-2.
150 		 */
151 		if (pr_reg->pr_res_holder) {
152 			core_scsi3_put_pr_reg(pr_reg);
153 			return 1;
154 		}
155 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
156 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
157 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
158 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
159 			core_scsi3_put_pr_reg(pr_reg);
160 			return 1;
161 		}
162 		core_scsi3_put_pr_reg(pr_reg);
163 		conflict = 1;
164 	} else {
165 		/*
166 		 * Following spc2r20 5.5.1 Reservations overview:
167 		 *
168 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
169 		 * command with the REGISTER or the REGISTER AND IGNORE
170 		 * EXISTING KEY service action and is still registered by any
171 		 * initiator, all RESERVE commands and all RELEASE commands
172 		 * regardless of initiator shall conflict and shall terminate
173 		 * with a RESERVATION CONFLICT status.
174 		 */
175 		spin_lock(&pr_tmpl->registration_lock);
176 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
177 		spin_unlock(&pr_tmpl->registration_lock);
178 	}
179 
180 	if (conflict) {
181 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
182 			" while active SPC-3 registrations exist,"
183 			" returning RESERVATION_CONFLICT\n");
184 		return -EBUSY;
185 	}
186 
187 	return 0;
188 }
189 
190 void target_release_reservation(struct se_device *dev)
191 {
192 	dev->reservation_holder = NULL;
193 	dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
194 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
195 		dev->dev_res_bin_isid = 0;
196 		dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS_WITH_ISID;
197 	}
198 }
199 
200 sense_reason_t
201 target_scsi2_reservation_release(struct se_cmd *cmd)
202 {
203 	struct se_device *dev = cmd->se_dev;
204 	struct se_session *sess = cmd->se_sess;
205 	struct se_portal_group *tpg;
206 	int rc;
207 
208 	if (!sess || !sess->se_tpg)
209 		goto out;
210 	rc = target_check_scsi2_reservation_conflict(cmd);
211 	if (rc == 1)
212 		goto out;
213 	if (rc < 0)
214 		return TCM_RESERVATION_CONFLICT;
215 
216 	spin_lock(&dev->dev_reservation_lock);
217 	if (!dev->reservation_holder || !sess)
218 		goto out_unlock;
219 
220 	if (dev->reservation_holder->se_node_acl != sess->se_node_acl)
221 		goto out_unlock;
222 
223 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
224 		goto out_unlock;
225 
226 	target_release_reservation(dev);
227 	tpg = sess->se_tpg;
228 	pr_debug("SCSI-2 Released reservation for %s LUN: %llu ->"
229 		" MAPPED LUN: %llu for %s\n",
230 		tpg->se_tpg_tfo->fabric_name,
231 		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
232 		sess->se_node_acl->initiatorname);
233 
234 out_unlock:
235 	spin_unlock(&dev->dev_reservation_lock);
236 out:
237 	target_complete_cmd(cmd, GOOD);
238 	return 0;
239 }
240 
241 sense_reason_t
242 target_scsi2_reservation_reserve(struct se_cmd *cmd)
243 {
244 	struct se_device *dev = cmd->se_dev;
245 	struct se_session *sess = cmd->se_sess;
246 	struct se_portal_group *tpg;
247 	sense_reason_t ret = 0;
248 	int rc;
249 
250 	if ((cmd->t_task_cdb[1] & 0x01) &&
251 	    (cmd->t_task_cdb[1] & 0x02)) {
252 		pr_err("LongIO and Obsolete Bits set, returning ILLEGAL_REQUEST\n");
253 		return TCM_UNSUPPORTED_SCSI_OPCODE;
254 	}
255 	/*
256 	 * This is currently the case for target_core_mod passthrough struct se_cmd
257 	 * ops
258 	 */
259 	if (!sess || !sess->se_tpg)
260 		goto out;
261 	rc = target_check_scsi2_reservation_conflict(cmd);
262 	if (rc == 1)
263 		goto out;
264 
265 	if (rc < 0)
266 		return TCM_RESERVATION_CONFLICT;
267 
268 	tpg = sess->se_tpg;
269 	spin_lock(&dev->dev_reservation_lock);
270 	if (dev->reservation_holder &&
271 	    dev->reservation_holder->se_node_acl != sess->se_node_acl) {
272 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
273 			tpg->se_tpg_tfo->fabric_name);
274 		pr_err("Original reserver LUN: %llu %s\n",
275 			cmd->se_lun->unpacked_lun,
276 			dev->reservation_holder->se_node_acl->initiatorname);
277 		pr_err("Current attempt - LUN: %llu -> MAPPED LUN: %llu"
278 			" from %s \n", cmd->se_lun->unpacked_lun,
279 			cmd->orig_fe_lun,
280 			sess->se_node_acl->initiatorname);
281 		ret = TCM_RESERVATION_CONFLICT;
282 		goto out_unlock;
283 	}
284 
285 	dev->reservation_holder = sess;
286 	dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS;
287 	if (sess->sess_bin_isid != 0) {
288 		dev->dev_res_bin_isid = sess->sess_bin_isid;
289 		dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS_WITH_ISID;
290 	}
291 	pr_debug("SCSI-2 Reserved %s LUN: %llu -> MAPPED LUN: %llu"
292 		" for %s\n", tpg->se_tpg_tfo->fabric_name,
293 		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
294 		sess->se_node_acl->initiatorname);
295 
296 out_unlock:
297 	spin_unlock(&dev->dev_reservation_lock);
298 out:
299 	if (!ret)
300 		target_complete_cmd(cmd, GOOD);
301 	return ret;
302 }
303 
304 
305 /*
306  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
307  *
308  * This function is called by those initiator ports who are *NOT*
309  * the active PR reservation holder when a reservation is present.
310  */
311 static int core_scsi3_pr_seq_non_holder(struct se_cmd *cmd, u32 pr_reg_type,
312 					bool isid_mismatch)
313 {
314 	unsigned char *cdb = cmd->t_task_cdb;
315 	struct se_session *se_sess = cmd->se_sess;
316 	struct se_node_acl *nacl = se_sess->se_node_acl;
317 	int other_cdb = 0;
318 	int registered_nexus = 0, ret = 1; /* Conflict by default */
319 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
320 	int we = 0; /* Write Exclusive */
321 	int legacy = 0; /* Act like a legacy device and return
322 			 * RESERVATION CONFLICT on some CDBs */
323 
324 	if (isid_mismatch) {
325 		registered_nexus = 0;
326 	} else {
327 		struct se_dev_entry *se_deve;
328 
329 		rcu_read_lock();
330 		se_deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
331 		if (se_deve)
332 			registered_nexus = test_bit(DEF_PR_REG_ACTIVE,
333 						    &se_deve->deve_flags);
334 		rcu_read_unlock();
335 	}
336 
337 	switch (pr_reg_type) {
338 	case PR_TYPE_WRITE_EXCLUSIVE:
339 		we = 1;
340 	case PR_TYPE_EXCLUSIVE_ACCESS:
341 		/*
342 		 * Some commands are only allowed for the persistent reservation
343 		 * holder.
344 		 */
345 		break;
346 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
347 		we = 1;
348 		fallthrough;
349 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
350 		/*
351 		 * Some commands are only allowed for registered I_T Nexuses.
352 		 */
353 		reg_only = 1;
354 		break;
355 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
356 		we = 1;
357 		fallthrough;
358 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
359 		/*
360 		 * Each registered I_T Nexus is a reservation holder.
361 		 */
362 		all_reg = 1;
363 		break;
364 	default:
365 		return -EINVAL;
366 	}
367 	/*
368 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
369 	 */
370 	switch (cdb[0]) {
371 	case SECURITY_PROTOCOL_IN:
372 		if (registered_nexus)
373 			return 0;
374 		ret = (we) ? 0 : 1;
375 		break;
376 	case MODE_SENSE:
377 	case MODE_SENSE_10:
378 	case READ_ATTRIBUTE:
379 	case READ_BUFFER:
380 	case RECEIVE_DIAGNOSTIC:
381 		if (legacy) {
382 			ret = 1;
383 			break;
384 		}
385 		if (registered_nexus) {
386 			ret = 0;
387 			break;
388 		}
389 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
390 		break;
391 	case PERSISTENT_RESERVE_OUT:
392 		/*
393 		 * This follows PERSISTENT_RESERVE_OUT service actions that
394 		 * are allowed in the presence of various reservations.
395 		 * See spc4r17, table 46
396 		 */
397 		switch (cdb[1] & 0x1f) {
398 		case PRO_CLEAR:
399 		case PRO_PREEMPT:
400 		case PRO_PREEMPT_AND_ABORT:
401 			ret = (registered_nexus) ? 0 : 1;
402 			break;
403 		case PRO_REGISTER:
404 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
405 			ret = 0;
406 			break;
407 		case PRO_REGISTER_AND_MOVE:
408 		case PRO_RESERVE:
409 			ret = 1;
410 			break;
411 		case PRO_RELEASE:
412 			ret = (registered_nexus) ? 0 : 1;
413 			break;
414 		default:
415 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
416 				" action: 0x%02x\n", cdb[1] & 0x1f);
417 			return -EINVAL;
418 		}
419 		break;
420 	case RELEASE:
421 	case RELEASE_10:
422 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
423 		ret = 0;
424 		break;
425 	case RESERVE:
426 	case RESERVE_10:
427 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
428 		ret = 0;
429 		break;
430 	case TEST_UNIT_READY:
431 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
432 		break;
433 	case MAINTENANCE_IN:
434 		switch (cdb[1] & 0x1f) {
435 		case MI_MANAGEMENT_PROTOCOL_IN:
436 			if (registered_nexus) {
437 				ret = 0;
438 				break;
439 			}
440 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
441 			break;
442 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
443 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
444 			if (legacy) {
445 				ret = 1;
446 				break;
447 			}
448 			if (registered_nexus) {
449 				ret = 0;
450 				break;
451 			}
452 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
453 			break;
454 		case MI_REPORT_ALIASES:
455 		case MI_REPORT_IDENTIFYING_INFORMATION:
456 		case MI_REPORT_PRIORITY:
457 		case MI_REPORT_TARGET_PGS:
458 		case MI_REPORT_TIMESTAMP:
459 			ret = 0; /* Allowed */
460 			break;
461 		default:
462 			pr_err("Unknown MI Service Action: 0x%02x\n",
463 				(cdb[1] & 0x1f));
464 			return -EINVAL;
465 		}
466 		break;
467 	case ACCESS_CONTROL_IN:
468 	case ACCESS_CONTROL_OUT:
469 	case INQUIRY:
470 	case LOG_SENSE:
471 	case SERVICE_ACTION_IN_12:
472 	case REPORT_LUNS:
473 	case REQUEST_SENSE:
474 	case PERSISTENT_RESERVE_IN:
475 		ret = 0; /*/ Allowed CDBs */
476 		break;
477 	default:
478 		other_cdb = 1;
479 		break;
480 	}
481 	/*
482 	 * Case where the CDB is explicitly allowed in the above switch
483 	 * statement.
484 	 */
485 	if (!ret && !other_cdb) {
486 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
487 			" reservation holder\n", cdb[0],
488 			core_scsi3_pr_dump_type(pr_reg_type));
489 
490 		return ret;
491 	}
492 	/*
493 	 * Check if write exclusive initiator ports *NOT* holding the
494 	 * WRITE_EXCLUSIVE_* reservation.
495 	 */
496 	if (we && !registered_nexus) {
497 		if (cmd->data_direction == DMA_TO_DEVICE) {
498 			/*
499 			 * Conflict for write exclusive
500 			 */
501 			pr_debug("%s Conflict for unregistered nexus"
502 				" %s CDB: 0x%02x to %s reservation\n",
503 				transport_dump_cmd_direction(cmd),
504 				se_sess->se_node_acl->initiatorname, cdb[0],
505 				core_scsi3_pr_dump_type(pr_reg_type));
506 			return 1;
507 		} else {
508 			/*
509 			 * Allow non WRITE CDBs for all Write Exclusive
510 			 * PR TYPEs to pass for registered and
511 			 * non-registered_nexuxes NOT holding the reservation.
512 			 *
513 			 * We only make noise for the unregisterd nexuses,
514 			 * as we expect registered non-reservation holding
515 			 * nexuses to issue CDBs.
516 			 */
517 
518 			if (!registered_nexus) {
519 				pr_debug("Allowing implicit CDB: 0x%02x"
520 					" for %s reservation on unregistered"
521 					" nexus\n", cdb[0],
522 					core_scsi3_pr_dump_type(pr_reg_type));
523 			}
524 
525 			return 0;
526 		}
527 	} else if ((reg_only) || (all_reg)) {
528 		if (registered_nexus) {
529 			/*
530 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
531 			 * allow commands from registered nexuses.
532 			 */
533 
534 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
535 				" reservation\n", cdb[0],
536 				core_scsi3_pr_dump_type(pr_reg_type));
537 
538 			return 0;
539 		}
540        } else if (we && registered_nexus) {
541                /*
542                 * Reads are allowed for Write Exclusive locks
543                 * from all registrants.
544                 */
545                if (cmd->data_direction == DMA_FROM_DEVICE) {
546                        pr_debug("Allowing READ CDB: 0x%02x for %s"
547                                " reservation\n", cdb[0],
548                                core_scsi3_pr_dump_type(pr_reg_type));
549 
550                        return 0;
551                }
552 	}
553 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
554 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
555 		(registered_nexus) ? "" : "un",
556 		se_sess->se_node_acl->initiatorname, cdb[0],
557 		core_scsi3_pr_dump_type(pr_reg_type));
558 
559 	return 1; /* Conflict by default */
560 }
561 
562 static sense_reason_t
563 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
564 {
565 	struct se_device *dev = cmd->se_dev;
566 	struct se_session *sess = cmd->se_sess;
567 	u32 pr_reg_type;
568 	bool isid_mismatch = false;
569 
570 	if (!dev->dev_pr_res_holder)
571 		return 0;
572 
573 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
574 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
575 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
576 		goto check_nonholder;
577 
578 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
579 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
580 		    sess->sess_bin_isid) {
581 			isid_mismatch = true;
582 			goto check_nonholder;
583 		}
584 	}
585 
586 	return 0;
587 
588 check_nonholder:
589 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type, isid_mismatch))
590 		return TCM_RESERVATION_CONFLICT;
591 	return 0;
592 }
593 
594 static u32 core_scsi3_pr_generation(struct se_device *dev)
595 {
596 	u32 prg;
597 
598 	/*
599 	 * PRGeneration field shall contain the value of a 32-bit wrapping
600 	 * counter mainted by the device server.
601 	 *
602 	 * Note that this is done regardless of Active Persist across
603 	 * Target PowerLoss (APTPL)
604 	 *
605 	 * See spc4r17 section 6.3.12 READ_KEYS service action
606 	 */
607 	spin_lock(&dev->dev_reservation_lock);
608 	prg = dev->t10_pr.pr_generation++;
609 	spin_unlock(&dev->dev_reservation_lock);
610 
611 	return prg;
612 }
613 
614 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
615 	struct se_device *dev,
616 	struct se_node_acl *nacl,
617 	struct se_lun *lun,
618 	struct se_dev_entry *dest_deve,
619 	u64 mapped_lun,
620 	unsigned char *isid,
621 	u64 sa_res_key,
622 	int all_tg_pt,
623 	int aptpl)
624 {
625 	struct t10_pr_registration *pr_reg;
626 
627 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
628 	if (!pr_reg) {
629 		pr_err("Unable to allocate struct t10_pr_registration\n");
630 		return NULL;
631 	}
632 
633 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
634 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
635 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
636 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
637 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
638 	atomic_set(&pr_reg->pr_res_holders, 0);
639 	pr_reg->pr_reg_nacl = nacl;
640 	/*
641 	 * For destination registrations for ALL_TG_PT=1 and SPEC_I_PT=1,
642 	 * the se_dev_entry->pr_ref will have been already obtained by
643 	 * core_get_se_deve_from_rtpi() or __core_scsi3_alloc_registration().
644 	 *
645 	 * Otherwise, locate se_dev_entry now and obtain a reference until
646 	 * registration completes in __core_scsi3_add_registration().
647 	 */
648 	if (dest_deve) {
649 		pr_reg->pr_reg_deve = dest_deve;
650 	} else {
651 		rcu_read_lock();
652 		pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
653 		if (!pr_reg->pr_reg_deve) {
654 			rcu_read_unlock();
655 			pr_err("Unable to locate PR deve %s mapped_lun: %llu\n",
656 				nacl->initiatorname, mapped_lun);
657 			kmem_cache_free(t10_pr_reg_cache, pr_reg);
658 			return NULL;
659 		}
660 		kref_get(&pr_reg->pr_reg_deve->pr_kref);
661 		rcu_read_unlock();
662 	}
663 	pr_reg->pr_res_mapped_lun = mapped_lun;
664 	pr_reg->pr_aptpl_target_lun = lun->unpacked_lun;
665 	pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
666 	pr_reg->pr_res_key = sa_res_key;
667 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
668 	pr_reg->pr_reg_aptpl = aptpl;
669 	/*
670 	 * If an ISID value for this SCSI Initiator Port exists,
671 	 * save it to the registration now.
672 	 */
673 	if (isid != NULL) {
674 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
675 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
676 		pr_reg->isid_present_at_reg = 1;
677 	}
678 
679 	return pr_reg;
680 }
681 
682 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
683 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
684 
685 /*
686  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
687  * modes.
688  */
689 static struct t10_pr_registration *__core_scsi3_alloc_registration(
690 	struct se_device *dev,
691 	struct se_node_acl *nacl,
692 	struct se_lun *lun,
693 	struct se_dev_entry *deve,
694 	u64 mapped_lun,
695 	unsigned char *isid,
696 	u64 sa_res_key,
697 	int all_tg_pt,
698 	int aptpl)
699 {
700 	struct se_dev_entry *deve_tmp;
701 	struct se_node_acl *nacl_tmp;
702 	struct se_lun_acl *lacl_tmp;
703 	struct se_lun *lun_tmp, *next, *dest_lun;
704 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
705 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
706 	int ret;
707 	/*
708 	 * Create a registration for the I_T Nexus upon which the
709 	 * PROUT REGISTER was received.
710 	 */
711 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, lun, deve, mapped_lun,
712 						    isid, sa_res_key, all_tg_pt,
713 						    aptpl);
714 	if (!pr_reg)
715 		return NULL;
716 	/*
717 	 * Return pointer to pr_reg for ALL_TG_PT=0
718 	 */
719 	if (!all_tg_pt)
720 		return pr_reg;
721 	/*
722 	 * Create list of matching SCSI Initiator Port registrations
723 	 * for ALL_TG_PT=1
724 	 */
725 	spin_lock(&dev->se_port_lock);
726 	list_for_each_entry_safe(lun_tmp, next, &dev->dev_sep_list, lun_dev_link) {
727 		if (!percpu_ref_tryget_live(&lun_tmp->lun_ref))
728 			continue;
729 		spin_unlock(&dev->se_port_lock);
730 
731 		spin_lock(&lun_tmp->lun_deve_lock);
732 		list_for_each_entry(deve_tmp, &lun_tmp->lun_deve_list, lun_link) {
733 			/*
734 			 * This pointer will be NULL for demo mode MappedLUNs
735 			 * that have not been make explicit via a ConfigFS
736 			 * MappedLUN group for the SCSI Initiator Node ACL.
737 			 */
738 			if (!deve_tmp->se_lun_acl)
739 				continue;
740 
741 			lacl_tmp = rcu_dereference_check(deve_tmp->se_lun_acl,
742 						lockdep_is_held(&lun_tmp->lun_deve_lock));
743 			nacl_tmp = lacl_tmp->se_lun_nacl;
744 			/*
745 			 * Skip the matching struct se_node_acl that is allocated
746 			 * above..
747 			 */
748 			if (nacl == nacl_tmp)
749 				continue;
750 			/*
751 			 * Only perform PR registrations for target ports on
752 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
753 			 * arrived.
754 			 */
755 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
756 				continue;
757 			/*
758 			 * Look for a matching Initiator Node ACL in ASCII format
759 			 */
760 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
761 				continue;
762 
763 			kref_get(&deve_tmp->pr_kref);
764 			spin_unlock(&lun_tmp->lun_deve_lock);
765 			/*
766 			 * Grab a configfs group dependency that is released
767 			 * for the exception path at label out: below, or upon
768 			 * completion of adding ALL_TG_PT=1 registrations in
769 			 * __core_scsi3_add_registration()
770 			 */
771 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
772 			if (ret < 0) {
773 				pr_err("core_scsi3_lunacl_depend"
774 						"_item() failed\n");
775 				percpu_ref_put(&lun_tmp->lun_ref);
776 				kref_put(&deve_tmp->pr_kref, target_pr_kref_release);
777 				goto out;
778 			}
779 			/*
780 			 * Located a matching SCSI Initiator Port on a different
781 			 * port, allocate the pr_reg_atp and attach it to the
782 			 * pr_reg->pr_reg_atp_list that will be processed once
783 			 * the original *pr_reg is processed in
784 			 * __core_scsi3_add_registration()
785 			 */
786 			dest_lun = rcu_dereference_check(deve_tmp->se_lun,
787 				kref_read(&deve_tmp->pr_kref) != 0);
788 
789 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
790 						nacl_tmp, dest_lun, deve_tmp,
791 						deve_tmp->mapped_lun, NULL,
792 						sa_res_key, all_tg_pt, aptpl);
793 			if (!pr_reg_atp) {
794 				percpu_ref_put(&lun_tmp->lun_ref);
795 				core_scsi3_lunacl_undepend_item(deve_tmp);
796 				goto out;
797 			}
798 
799 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
800 				      &pr_reg->pr_reg_atp_list);
801 			spin_lock(&lun_tmp->lun_deve_lock);
802 		}
803 		spin_unlock(&lun_tmp->lun_deve_lock);
804 
805 		spin_lock(&dev->se_port_lock);
806 		percpu_ref_put(&lun_tmp->lun_ref);
807 	}
808 	spin_unlock(&dev->se_port_lock);
809 
810 	return pr_reg;
811 out:
812 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
813 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
814 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
815 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
816 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
817 	}
818 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
819 	return NULL;
820 }
821 
822 int core_scsi3_alloc_aptpl_registration(
823 	struct t10_reservation *pr_tmpl,
824 	u64 sa_res_key,
825 	unsigned char *i_port,
826 	unsigned char *isid,
827 	u64 mapped_lun,
828 	unsigned char *t_port,
829 	u16 tpgt,
830 	u64 target_lun,
831 	int res_holder,
832 	int all_tg_pt,
833 	u8 type)
834 {
835 	struct t10_pr_registration *pr_reg;
836 
837 	if (!i_port || !t_port || !sa_res_key) {
838 		pr_err("Illegal parameters for APTPL registration\n");
839 		return -EINVAL;
840 	}
841 
842 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
843 	if (!pr_reg) {
844 		pr_err("Unable to allocate struct t10_pr_registration\n");
845 		return -ENOMEM;
846 	}
847 
848 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
849 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
850 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
851 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
852 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
853 	atomic_set(&pr_reg->pr_res_holders, 0);
854 	pr_reg->pr_reg_nacl = NULL;
855 	pr_reg->pr_reg_deve = NULL;
856 	pr_reg->pr_res_mapped_lun = mapped_lun;
857 	pr_reg->pr_aptpl_target_lun = target_lun;
858 	pr_reg->pr_res_key = sa_res_key;
859 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
860 	pr_reg->pr_reg_aptpl = 1;
861 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
862 	pr_reg->pr_res_type = type;
863 	/*
864 	 * If an ISID value had been saved in APTPL metadata for this
865 	 * SCSI Initiator Port, restore it now.
866 	 */
867 	if (isid != NULL) {
868 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
869 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
870 		pr_reg->isid_present_at_reg = 1;
871 	}
872 	/*
873 	 * Copy the i_port and t_port information from caller.
874 	 */
875 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
876 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
877 	pr_reg->pr_reg_tpgt = tpgt;
878 	/*
879 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
880 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
881 	 * the Initiator Node LUN ACL from the fabric module is created for
882 	 * this registration.
883 	 */
884 	pr_reg->pr_res_holder = res_holder;
885 
886 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
887 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
888 			" metadata\n", (res_holder) ? "+reservation" : "");
889 	return 0;
890 }
891 
892 static void core_scsi3_aptpl_reserve(
893 	struct se_device *dev,
894 	struct se_portal_group *tpg,
895 	struct se_node_acl *node_acl,
896 	struct t10_pr_registration *pr_reg)
897 {
898 	char i_buf[PR_REG_ISID_ID_LEN];
899 
900 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
901 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
902 
903 	spin_lock(&dev->dev_reservation_lock);
904 	dev->dev_pr_res_holder = pr_reg;
905 	spin_unlock(&dev->dev_reservation_lock);
906 
907 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
908 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
909 		tpg->se_tpg_tfo->fabric_name,
910 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
911 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
912 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
913 		tpg->se_tpg_tfo->fabric_name, node_acl->initiatorname,
914 		i_buf);
915 }
916 
917 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
918 				struct t10_pr_registration *, enum register_type, int);
919 
920 static int __core_scsi3_check_aptpl_registration(
921 	struct se_device *dev,
922 	struct se_portal_group *tpg,
923 	struct se_lun *lun,
924 	u64 target_lun,
925 	struct se_node_acl *nacl,
926 	u64 mapped_lun)
927 {
928 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
929 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
930 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
931 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
932 	u16 tpgt;
933 
934 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
935 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
936 	/*
937 	 * Copy Initiator Port information from struct se_node_acl
938 	 */
939 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
940 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
941 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
942 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
943 	/*
944 	 * Look for the matching registrations+reservation from those
945 	 * created from APTPL metadata.  Note that multiple registrations
946 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
947 	 * TransportIDs.
948 	 */
949 	spin_lock(&pr_tmpl->aptpl_reg_lock);
950 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
951 				pr_reg_aptpl_list) {
952 
953 		if (!strcmp(pr_reg->pr_iport, i_port) &&
954 		     (pr_reg->pr_res_mapped_lun == mapped_lun) &&
955 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
956 		     (pr_reg->pr_reg_tpgt == tpgt) &&
957 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
958 			/*
959 			 * Obtain the ->pr_reg_deve pointer + reference, that
960 			 * is released by __core_scsi3_add_registration() below.
961 			 */
962 			rcu_read_lock();
963 			pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
964 			if (!pr_reg->pr_reg_deve) {
965 				pr_err("Unable to locate PR APTPL %s mapped_lun:"
966 					" %llu\n", nacl->initiatorname, mapped_lun);
967 				rcu_read_unlock();
968 				continue;
969 			}
970 			kref_get(&pr_reg->pr_reg_deve->pr_kref);
971 			rcu_read_unlock();
972 
973 			pr_reg->pr_reg_nacl = nacl;
974 			pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
975 			list_del(&pr_reg->pr_reg_aptpl_list);
976 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
977 			/*
978 			 * At this point all of the pointers in *pr_reg will
979 			 * be setup, so go ahead and add the registration.
980 			 */
981 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
982 			/*
983 			 * If this registration is the reservation holder,
984 			 * make that happen now..
985 			 */
986 			if (pr_reg->pr_res_holder)
987 				core_scsi3_aptpl_reserve(dev, tpg,
988 						nacl, pr_reg);
989 			/*
990 			 * Reenable pr_aptpl_active to accept new metadata
991 			 * updates once the SCSI device is active again..
992 			 */
993 			spin_lock(&pr_tmpl->aptpl_reg_lock);
994 			pr_tmpl->pr_aptpl_active = 1;
995 		}
996 	}
997 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
998 
999 	return 0;
1000 }
1001 
1002 int core_scsi3_check_aptpl_registration(
1003 	struct se_device *dev,
1004 	struct se_portal_group *tpg,
1005 	struct se_lun *lun,
1006 	struct se_node_acl *nacl,
1007 	u64 mapped_lun)
1008 {
1009 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
1010 		return 0;
1011 
1012 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
1013 						     lun->unpacked_lun, nacl,
1014 						     mapped_lun);
1015 }
1016 
1017 static void __core_scsi3_dump_registration(
1018 	const struct target_core_fabric_ops *tfo,
1019 	struct se_device *dev,
1020 	struct se_node_acl *nacl,
1021 	struct t10_pr_registration *pr_reg,
1022 	enum register_type register_type)
1023 {
1024 	struct se_portal_group *se_tpg = nacl->se_tpg;
1025 	char i_buf[PR_REG_ISID_ID_LEN];
1026 
1027 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
1028 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1029 
1030 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1031 		" Node: %s%s\n", tfo->fabric_name, (register_type == REGISTER_AND_MOVE) ?
1032 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
1033 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1034 		i_buf);
1035 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1036 		 tfo->fabric_name, tfo->tpg_get_wwn(se_tpg),
1037 		tfo->tpg_get_tag(se_tpg));
1038 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1039 		" Port(s)\n",  tfo->fabric_name,
1040 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1041 		dev->transport->name);
1042 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1043 		" 0x%08x  APTPL: %d\n", tfo->fabric_name,
1044 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1045 		pr_reg->pr_reg_aptpl);
1046 }
1047 
1048 static void __core_scsi3_add_registration(
1049 	struct se_device *dev,
1050 	struct se_node_acl *nacl,
1051 	struct t10_pr_registration *pr_reg,
1052 	enum register_type register_type,
1053 	int register_move)
1054 {
1055 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1056 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1057 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1058 	struct se_dev_entry *deve;
1059 
1060 	/*
1061 	 * Increment PRgeneration counter for struct se_device upon a successful
1062 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1063 	 *
1064 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1065 	 * action, the struct se_device->dev_reservation_lock will already be held,
1066 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1067 	 * for the REGISTER.
1068 	 */
1069 	pr_reg->pr_res_generation = (register_move) ?
1070 			dev->t10_pr.pr_generation++ :
1071 			core_scsi3_pr_generation(dev);
1072 
1073 	spin_lock(&pr_tmpl->registration_lock);
1074 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1075 
1076 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1077 	spin_unlock(&pr_tmpl->registration_lock);
1078 	/*
1079 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1080 	 */
1081 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1082 		goto out;
1083 	/*
1084 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1085 	 * allocated in __core_scsi3_alloc_registration()
1086 	 */
1087 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1088 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1089 		struct se_node_acl *nacl_tmp = pr_reg_tmp->pr_reg_nacl;
1090 
1091 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1092 
1093 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1094 
1095 		spin_lock(&pr_tmpl->registration_lock);
1096 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1097 			      &pr_tmpl->registration_list);
1098 
1099 		__core_scsi3_dump_registration(tfo, dev, nacl_tmp, pr_reg_tmp,
1100 					       register_type);
1101 		spin_unlock(&pr_tmpl->registration_lock);
1102 		/*
1103 		 * Drop configfs group dependency reference and deve->pr_kref
1104 		 * obtained from  __core_scsi3_alloc_registration() code.
1105 		 */
1106 		rcu_read_lock();
1107 		deve = pr_reg_tmp->pr_reg_deve;
1108 		if (deve) {
1109 			set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1110 			core_scsi3_lunacl_undepend_item(deve);
1111 			pr_reg_tmp->pr_reg_deve = NULL;
1112 		}
1113 		rcu_read_unlock();
1114 	}
1115 out:
1116 	/*
1117 	 * Drop deve->pr_kref obtained in __core_scsi3_do_alloc_registration()
1118 	 */
1119 	rcu_read_lock();
1120 	deve = pr_reg->pr_reg_deve;
1121 	if (deve) {
1122 		set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1123 		kref_put(&deve->pr_kref, target_pr_kref_release);
1124 		pr_reg->pr_reg_deve = NULL;
1125 	}
1126 	rcu_read_unlock();
1127 }
1128 
1129 static int core_scsi3_alloc_registration(
1130 	struct se_device *dev,
1131 	struct se_node_acl *nacl,
1132 	struct se_lun *lun,
1133 	struct se_dev_entry *deve,
1134 	u64 mapped_lun,
1135 	unsigned char *isid,
1136 	u64 sa_res_key,
1137 	int all_tg_pt,
1138 	int aptpl,
1139 	enum register_type register_type,
1140 	int register_move)
1141 {
1142 	struct t10_pr_registration *pr_reg;
1143 
1144 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, lun, deve, mapped_lun,
1145 						 isid, sa_res_key, all_tg_pt,
1146 						 aptpl);
1147 	if (!pr_reg)
1148 		return -EPERM;
1149 
1150 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1151 			register_type, register_move);
1152 	return 0;
1153 }
1154 
1155 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1156 	struct se_device *dev,
1157 	struct se_node_acl *nacl,
1158 	unsigned char *isid)
1159 {
1160 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1161 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1162 
1163 	spin_lock(&pr_tmpl->registration_lock);
1164 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1165 			&pr_tmpl->registration_list, pr_reg_list) {
1166 		/*
1167 		 * First look for a matching struct se_node_acl
1168 		 */
1169 		if (pr_reg->pr_reg_nacl != nacl)
1170 			continue;
1171 
1172 		/*
1173 		 * If this registration does NOT contain a fabric provided
1174 		 * ISID, then we have found a match.
1175 		 */
1176 		if (!pr_reg->isid_present_at_reg) {
1177 			atomic_inc_mb(&pr_reg->pr_res_holders);
1178 			spin_unlock(&pr_tmpl->registration_lock);
1179 			return pr_reg;
1180 		}
1181 		/*
1182 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1183 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1184 		 * matching ISID to be provided by the local SCSI Initiator Port.
1185 		 */
1186 		if (!isid)
1187 			continue;
1188 		if (strcmp(isid, pr_reg->pr_reg_isid))
1189 			continue;
1190 
1191 		atomic_inc_mb(&pr_reg->pr_res_holders);
1192 		spin_unlock(&pr_tmpl->registration_lock);
1193 		return pr_reg;
1194 	}
1195 	spin_unlock(&pr_tmpl->registration_lock);
1196 
1197 	return NULL;
1198 }
1199 
1200 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1201 	struct se_device *dev,
1202 	struct se_node_acl *nacl,
1203 	struct se_session *sess)
1204 {
1205 	struct se_portal_group *tpg = nacl->se_tpg;
1206 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1207 
1208 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1209 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1210 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1211 					PR_REG_ISID_LEN);
1212 		isid_ptr = &buf[0];
1213 	}
1214 
1215 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1216 }
1217 
1218 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1219 {
1220 	atomic_dec_mb(&pr_reg->pr_res_holders);
1221 }
1222 
1223 static int core_scsi3_check_implicit_release(
1224 	struct se_device *dev,
1225 	struct t10_pr_registration *pr_reg)
1226 {
1227 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1228 	struct t10_pr_registration *pr_res_holder;
1229 	int ret = 0;
1230 
1231 	spin_lock(&dev->dev_reservation_lock);
1232 	pr_res_holder = dev->dev_pr_res_holder;
1233 	if (!pr_res_holder) {
1234 		spin_unlock(&dev->dev_reservation_lock);
1235 		return ret;
1236 	}
1237 	if (pr_res_holder == pr_reg) {
1238 		/*
1239 		 * Perform an implicit RELEASE if the registration that
1240 		 * is being released is holding the reservation.
1241 		 *
1242 		 * From spc4r17, section 5.7.11.1:
1243 		 *
1244 		 * e) If the I_T nexus is the persistent reservation holder
1245 		 *    and the persistent reservation is not an all registrants
1246 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1247 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1248 		 *    service action with the SERVICE ACTION RESERVATION KEY
1249 		 *    field set to zero (see 5.7.11.3).
1250 		 */
1251 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1252 		ret = 1;
1253 		/*
1254 		 * For 'All Registrants' reservation types, all existing
1255 		 * registrations are still processed as reservation holders
1256 		 * in core_scsi3_pr_seq_non_holder() after the initial
1257 		 * reservation holder is implicitly released here.
1258 		 */
1259 	} else if (pr_reg->pr_reg_all_tg_pt &&
1260 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1261 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1262 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1263 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1264 			" UNREGISTER while existing reservation with matching"
1265 			" key 0x%016Lx is present from another SCSI Initiator"
1266 			" Port\n", pr_reg->pr_res_key);
1267 		ret = -EPERM;
1268 	}
1269 	spin_unlock(&dev->dev_reservation_lock);
1270 
1271 	return ret;
1272 }
1273 
1274 static void __core_scsi3_free_registration(
1275 	struct se_device *dev,
1276 	struct t10_pr_registration *pr_reg,
1277 	struct list_head *preempt_and_abort_list,
1278 	int dec_holders)
1279 	__releases(&pr_tmpl->registration_lock)
1280 	__acquires(&pr_tmpl->registration_lock)
1281 {
1282 	const struct target_core_fabric_ops *tfo =
1283 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1284 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1285 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1286 	struct se_dev_entry *deve;
1287 	char i_buf[PR_REG_ISID_ID_LEN];
1288 
1289 	lockdep_assert_held(&pr_tmpl->registration_lock);
1290 
1291 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1292 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1293 
1294 	if (!list_empty(&pr_reg->pr_reg_list))
1295 		list_del(&pr_reg->pr_reg_list);
1296 	/*
1297 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1298 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1299 	 */
1300 	if (dec_holders)
1301 		core_scsi3_put_pr_reg(pr_reg);
1302 
1303 	spin_unlock(&pr_tmpl->registration_lock);
1304 	/*
1305 	 * Wait until all reference from any other I_T nexuses for this
1306 	 * *pr_reg have been released.  Because list_del() is called above,
1307 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1308 	 * count back to zero, and we release *pr_reg.
1309 	 */
1310 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1311 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1312 				tfo->fabric_name);
1313 		cpu_relax();
1314 	}
1315 
1316 	rcu_read_lock();
1317 	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
1318 	if (deve)
1319 		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1320 	rcu_read_unlock();
1321 
1322 	spin_lock(&pr_tmpl->registration_lock);
1323 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1324 		" Node: %s%s\n", tfo->fabric_name,
1325 		pr_reg->pr_reg_nacl->initiatorname,
1326 		i_buf);
1327 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1328 		" Port(s)\n", tfo->fabric_name,
1329 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1330 		dev->transport->name);
1331 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1332 		" 0x%08x\n", tfo->fabric_name, pr_reg->pr_res_key,
1333 		pr_reg->pr_res_generation);
1334 
1335 	if (!preempt_and_abort_list) {
1336 		pr_reg->pr_reg_deve = NULL;
1337 		pr_reg->pr_reg_nacl = NULL;
1338 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1339 		return;
1340 	}
1341 	/*
1342 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1343 	 * are released once the ABORT_TASK_SET has completed..
1344 	 */
1345 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1346 }
1347 
1348 void core_scsi3_free_pr_reg_from_nacl(
1349 	struct se_device *dev,
1350 	struct se_node_acl *nacl)
1351 {
1352 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1353 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1354 	bool free_reg = false;
1355 	/*
1356 	 * If the passed se_node_acl matches the reservation holder,
1357 	 * release the reservation.
1358 	 */
1359 	spin_lock(&dev->dev_reservation_lock);
1360 	pr_res_holder = dev->dev_pr_res_holder;
1361 	if ((pr_res_holder != NULL) &&
1362 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1363 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1364 		free_reg = true;
1365 	}
1366 	spin_unlock(&dev->dev_reservation_lock);
1367 	/*
1368 	 * Release any registration associated with the struct se_node_acl.
1369 	 */
1370 	spin_lock(&pr_tmpl->registration_lock);
1371 	if (pr_res_holder && free_reg)
1372 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1373 
1374 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1375 			&pr_tmpl->registration_list, pr_reg_list) {
1376 
1377 		if (pr_reg->pr_reg_nacl != nacl)
1378 			continue;
1379 
1380 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1381 	}
1382 	spin_unlock(&pr_tmpl->registration_lock);
1383 }
1384 
1385 void core_scsi3_free_all_registrations(
1386 	struct se_device *dev)
1387 {
1388 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1389 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1390 
1391 	spin_lock(&dev->dev_reservation_lock);
1392 	pr_res_holder = dev->dev_pr_res_holder;
1393 	if (pr_res_holder != NULL) {
1394 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1395 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1396 						  pr_res_holder, 0, 0);
1397 	}
1398 	spin_unlock(&dev->dev_reservation_lock);
1399 
1400 	spin_lock(&pr_tmpl->registration_lock);
1401 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1402 			&pr_tmpl->registration_list, pr_reg_list) {
1403 
1404 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1405 	}
1406 	spin_unlock(&pr_tmpl->registration_lock);
1407 
1408 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1409 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1410 				pr_reg_aptpl_list) {
1411 		list_del(&pr_reg->pr_reg_aptpl_list);
1412 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1413 	}
1414 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1415 }
1416 
1417 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1418 {
1419 	return target_depend_item(&tpg->tpg_group.cg_item);
1420 }
1421 
1422 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1423 {
1424 	target_undepend_item(&tpg->tpg_group.cg_item);
1425 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1426 }
1427 
1428 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1429 {
1430 	if (nacl->dynamic_node_acl)
1431 		return 0;
1432 	return target_depend_item(&nacl->acl_group.cg_item);
1433 }
1434 
1435 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1436 {
1437 	if (!nacl->dynamic_node_acl)
1438 		target_undepend_item(&nacl->acl_group.cg_item);
1439 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1440 }
1441 
1442 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1443 {
1444 	struct se_lun_acl *lun_acl;
1445 
1446 	/*
1447 	 * For nacl->dynamic_node_acl=1
1448 	 */
1449 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1450 				kref_read(&se_deve->pr_kref) != 0);
1451 	if (!lun_acl)
1452 		return 0;
1453 
1454 	return target_depend_item(&lun_acl->se_lun_group.cg_item);
1455 }
1456 
1457 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1458 {
1459 	struct se_lun_acl *lun_acl;
1460 
1461 	/*
1462 	 * For nacl->dynamic_node_acl=1
1463 	 */
1464 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1465 				kref_read(&se_deve->pr_kref) != 0);
1466 	if (!lun_acl) {
1467 		kref_put(&se_deve->pr_kref, target_pr_kref_release);
1468 		return;
1469 	}
1470 
1471 	target_undepend_item(&lun_acl->se_lun_group.cg_item);
1472 	kref_put(&se_deve->pr_kref, target_pr_kref_release);
1473 }
1474 
1475 static sense_reason_t
1476 core_scsi3_decode_spec_i_port(
1477 	struct se_cmd *cmd,
1478 	struct se_portal_group *tpg,
1479 	unsigned char *l_isid,
1480 	u64 sa_res_key,
1481 	int all_tg_pt,
1482 	int aptpl)
1483 {
1484 	struct se_device *dev = cmd->se_dev;
1485 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1486 	struct se_session *se_sess = cmd->se_sess;
1487 	struct se_node_acl *dest_node_acl = NULL;
1488 	struct se_dev_entry *dest_se_deve = NULL;
1489 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1490 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1491 	LIST_HEAD(tid_dest_list);
1492 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1493 	unsigned char *buf, *ptr, proto_ident;
1494 	const unsigned char *i_str = NULL;
1495 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1496 	sense_reason_t ret;
1497 	u32 tpdl, tid_len = 0;
1498 	u32 dest_rtpi = 0;
1499 
1500 	/*
1501 	 * Allocate a struct pr_transport_id_holder and setup the
1502 	 * local_node_acl pointer and add to struct list_head tid_dest_list
1503 	 * for add registration processing in the loop of tid_dest_list below.
1504 	 */
1505 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1506 	if (!tidh_new) {
1507 		pr_err("Unable to allocate tidh_new\n");
1508 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1509 	}
1510 	INIT_LIST_HEAD(&tidh_new->dest_list);
1511 	tidh_new->dest_tpg = tpg;
1512 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1513 
1514 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1515 				se_sess->se_node_acl, cmd->se_lun,
1516 				NULL, cmd->orig_fe_lun, l_isid,
1517 				sa_res_key, all_tg_pt, aptpl);
1518 	if (!local_pr_reg) {
1519 		kfree(tidh_new);
1520 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1521 	}
1522 
1523 	if (core_scsi3_lunacl_depend_item(local_pr_reg->pr_reg_deve)) {
1524 		kfree(tidh_new);
1525 		kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1526 			 target_pr_kref_release);
1527 		kmem_cache_free(t10_pr_reg_cache, local_pr_reg);
1528 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1529 	}
1530 
1531 	tidh_new->dest_pr_reg = local_pr_reg;
1532 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1533 
1534 	if (cmd->data_length < 28) {
1535 		pr_warn("SPC-PR: Received PR OUT parameter list"
1536 			" length too small: %u\n", cmd->data_length);
1537 		ret = TCM_INVALID_PARAMETER_LIST;
1538 		goto out;
1539 	}
1540 
1541 	buf = transport_kmap_data_sg(cmd);
1542 	if (!buf) {
1543 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1544 		goto out;
1545 	}
1546 
1547 	/*
1548 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1549 	 * first extract TransportID Parameter Data Length, and make sure
1550 	 * the value matches up to the SCSI expected data transfer length.
1551 	 */
1552 	tpdl = get_unaligned_be32(&buf[24]);
1553 
1554 	if ((tpdl + 28) != cmd->data_length) {
1555 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1556 			" does not equal CDB data_length: %u\n", tpdl,
1557 			cmd->data_length);
1558 		ret = TCM_INVALID_PARAMETER_LIST;
1559 		goto out_unmap;
1560 	}
1561 	/*
1562 	 * Start processing the received transport IDs using the
1563 	 * receiving I_T Nexus portal's fabric dependent methods to
1564 	 * obtain the SCSI Initiator Port/Device Identifiers.
1565 	 */
1566 	ptr = &buf[28];
1567 
1568 	while (tpdl > 0) {
1569 		struct se_lun *dest_lun, *tmp_lun;
1570 
1571 		proto_ident = (ptr[0] & 0x0f);
1572 		dest_tpg = NULL;
1573 
1574 		spin_lock(&dev->se_port_lock);
1575 		list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
1576 			tmp_tpg = tmp_lun->lun_tpg;
1577 
1578 			/*
1579 			 * Look for the matching proto_ident provided by
1580 			 * the received TransportID
1581 			 */
1582 			if (tmp_tpg->proto_id != proto_ident)
1583 				continue;
1584 			dest_rtpi = tmp_lun->lun_rtpi;
1585 
1586 			iport_ptr = NULL;
1587 			i_str = target_parse_pr_out_transport_id(tmp_tpg,
1588 					ptr, &tid_len, &iport_ptr);
1589 			if (!i_str)
1590 				continue;
1591 			/*
1592 			 * Determine if this SCSI device server requires that
1593 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1594 			 * for fabric modules (iSCSI) requiring them.
1595 			 */
1596 			if (tpg->se_tpg_tfo->sess_get_initiator_sid &&
1597 			    dev->dev_attrib.enforce_pr_isids &&
1598 			    !iport_ptr) {
1599 				pr_warn("SPC-PR: enforce_pr_isids is set but a isid has not been sent in the SPEC_I_PT data for %s.",
1600 					i_str);
1601 				ret = TCM_INVALID_PARAMETER_LIST;
1602 				spin_unlock(&dev->se_port_lock);
1603 				goto out_unmap;
1604 			}
1605 
1606 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1607 			spin_unlock(&dev->se_port_lock);
1608 
1609 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1610 				pr_err(" core_scsi3_tpg_depend_item()"
1611 					" for tmp_tpg\n");
1612 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1613 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1614 				goto out_unmap;
1615 			}
1616 			/*
1617 			 * Locate the destination initiator ACL to be registered
1618 			 * from the decoded fabric module specific TransportID
1619 			 * at *i_str.
1620 			 */
1621 			mutex_lock(&tmp_tpg->acl_node_mutex);
1622 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1623 						tmp_tpg, i_str);
1624 			if (dest_node_acl)
1625 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1626 			mutex_unlock(&tmp_tpg->acl_node_mutex);
1627 
1628 			if (!dest_node_acl) {
1629 				core_scsi3_tpg_undepend_item(tmp_tpg);
1630 				spin_lock(&dev->se_port_lock);
1631 				continue;
1632 			}
1633 
1634 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1635 				pr_err("configfs_depend_item() failed"
1636 					" for dest_node_acl->acl_group\n");
1637 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1638 				core_scsi3_tpg_undepend_item(tmp_tpg);
1639 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1640 				goto out_unmap;
1641 			}
1642 
1643 			dest_tpg = tmp_tpg;
1644 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1645 				" %s Port RTPI: %hu\n",
1646 				dest_tpg->se_tpg_tfo->fabric_name,
1647 				dest_node_acl->initiatorname, dest_rtpi);
1648 
1649 			spin_lock(&dev->se_port_lock);
1650 			break;
1651 		}
1652 		spin_unlock(&dev->se_port_lock);
1653 
1654 		if (!dest_tpg) {
1655 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1656 					" dest_tpg\n");
1657 			ret = TCM_INVALID_PARAMETER_LIST;
1658 			goto out_unmap;
1659 		}
1660 
1661 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1662 			" tid_len: %d for %s + %s\n",
1663 			dest_tpg->se_tpg_tfo->fabric_name, cmd->data_length,
1664 			tpdl, tid_len, i_str, iport_ptr);
1665 
1666 		if (tid_len > tpdl) {
1667 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1668 				" %u for Transport ID: %s\n", tid_len, ptr);
1669 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1670 			core_scsi3_tpg_undepend_item(dest_tpg);
1671 			ret = TCM_INVALID_PARAMETER_LIST;
1672 			goto out_unmap;
1673 		}
1674 		/*
1675 		 * Locate the desintation struct se_dev_entry pointer for matching
1676 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1677 		 * Target Port.
1678 		 */
1679 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1680 					dest_rtpi);
1681 		if (!dest_se_deve) {
1682 			pr_err("Unable to locate %s dest_se_deve"
1683 				" from destination RTPI: %hu\n",
1684 				dest_tpg->se_tpg_tfo->fabric_name,
1685 				dest_rtpi);
1686 
1687 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1688 			core_scsi3_tpg_undepend_item(dest_tpg);
1689 			ret = TCM_INVALID_PARAMETER_LIST;
1690 			goto out_unmap;
1691 		}
1692 
1693 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1694 			pr_err("core_scsi3_lunacl_depend_item()"
1695 					" failed\n");
1696 			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
1697 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1698 			core_scsi3_tpg_undepend_item(dest_tpg);
1699 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1700 			goto out_unmap;
1701 		}
1702 
1703 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1704 			" dest_se_deve mapped_lun: %llu\n",
1705 			dest_tpg->se_tpg_tfo->fabric_name,
1706 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1707 
1708 		/*
1709 		 * Skip any TransportIDs that already have a registration for
1710 		 * this target port.
1711 		 */
1712 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1713 					iport_ptr);
1714 		if (pr_reg_e) {
1715 			core_scsi3_put_pr_reg(pr_reg_e);
1716 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1717 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1718 			core_scsi3_tpg_undepend_item(dest_tpg);
1719 			ptr += tid_len;
1720 			tpdl -= tid_len;
1721 			tid_len = 0;
1722 			continue;
1723 		}
1724 		/*
1725 		 * Allocate a struct pr_transport_id_holder and setup
1726 		 * the dest_node_acl and dest_se_deve pointers for the
1727 		 * loop below.
1728 		 */
1729 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1730 				GFP_KERNEL);
1731 		if (!tidh_new) {
1732 			pr_err("Unable to allocate tidh_new\n");
1733 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1734 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1735 			core_scsi3_tpg_undepend_item(dest_tpg);
1736 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1737 			goto out_unmap;
1738 		}
1739 		INIT_LIST_HEAD(&tidh_new->dest_list);
1740 		tidh_new->dest_tpg = dest_tpg;
1741 		tidh_new->dest_node_acl = dest_node_acl;
1742 		tidh_new->dest_se_deve = dest_se_deve;
1743 
1744 		/*
1745 		 * Allocate, but do NOT add the registration for the
1746 		 * TransportID referenced SCSI Initiator port.  This
1747 		 * done because of the following from spc4r17 in section
1748 		 * 6.14.3 wrt SPEC_I_PT:
1749 		 *
1750 		 * "If a registration fails for any initiator port (e.g., if th
1751 		 * logical unit does not have enough resources available to
1752 		 * hold the registration information), no registrations shall be
1753 		 * made, and the command shall be terminated with
1754 		 * CHECK CONDITION status."
1755 		 *
1756 		 * That means we call __core_scsi3_alloc_registration() here,
1757 		 * and then call __core_scsi3_add_registration() in the
1758 		 * 2nd loop which will never fail.
1759 		 */
1760 		dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
1761 				kref_read(&dest_se_deve->pr_kref) != 0);
1762 
1763 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1764 					dest_node_acl, dest_lun, dest_se_deve,
1765 					dest_se_deve->mapped_lun, iport_ptr,
1766 					sa_res_key, all_tg_pt, aptpl);
1767 		if (!dest_pr_reg) {
1768 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1769 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1770 			core_scsi3_tpg_undepend_item(dest_tpg);
1771 			kfree(tidh_new);
1772 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1773 			goto out_unmap;
1774 		}
1775 		tidh_new->dest_pr_reg = dest_pr_reg;
1776 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1777 
1778 		ptr += tid_len;
1779 		tpdl -= tid_len;
1780 		tid_len = 0;
1781 
1782 	}
1783 
1784 	transport_kunmap_data_sg(cmd);
1785 
1786 	/*
1787 	 * Go ahead and create a registrations from tid_dest_list for the
1788 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1789 	 * and dest_se_deve.
1790 	 *
1791 	 * The SA Reservation Key from the PROUT is set for the
1792 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1793 	 * means that the TransportID Initiator port will be
1794 	 * registered on all of the target ports in the SCSI target device
1795 	 * ALL_TG_PT=0 means the registration will only be for the
1796 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1797 	 * was received.
1798 	 */
1799 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1800 		dest_tpg = tidh->dest_tpg;
1801 		dest_node_acl = tidh->dest_node_acl;
1802 		dest_se_deve = tidh->dest_se_deve;
1803 		dest_pr_reg = tidh->dest_pr_reg;
1804 
1805 		list_del(&tidh->dest_list);
1806 		kfree(tidh);
1807 
1808 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1809 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1810 
1811 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1812 					dest_pr_reg, 0, 0);
1813 
1814 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1815 			" registered Transport ID for Node: %s%s Mapped LUN:"
1816 			" %llu\n", dest_tpg->se_tpg_tfo->fabric_name,
1817 			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
1818 			dest_se_deve->mapped_lun : 0);
1819 
1820 		if (dest_pr_reg == local_pr_reg)
1821 			continue;
1822 
1823 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1824 		core_scsi3_tpg_undepend_item(dest_tpg);
1825 	}
1826 
1827 	return 0;
1828 out_unmap:
1829 	transport_kunmap_data_sg(cmd);
1830 out:
1831 	/*
1832 	 * For the failure case, release everything from tid_dest_list
1833 	 * including *dest_pr_reg and the configfs dependances..
1834 	 */
1835 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1836 		bool is_local = false;
1837 
1838 		dest_tpg = tidh->dest_tpg;
1839 		dest_node_acl = tidh->dest_node_acl;
1840 		dest_se_deve = tidh->dest_se_deve;
1841 		dest_pr_reg = tidh->dest_pr_reg;
1842 
1843 		if (dest_pr_reg == local_pr_reg)
1844 			is_local = true;
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 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1862 
1863 		if (is_local)
1864 			continue;
1865 
1866 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1867 		core_scsi3_tpg_undepend_item(dest_tpg);
1868 	}
1869 	return ret;
1870 }
1871 
1872 static int core_scsi3_update_aptpl_buf(
1873 	struct se_device *dev,
1874 	unsigned char *buf,
1875 	u32 pr_aptpl_buf_len)
1876 {
1877 	struct se_portal_group *tpg;
1878 	struct t10_pr_registration *pr_reg;
1879 	unsigned char tmp[512], isid_buf[32];
1880 	ssize_t len = 0;
1881 	int reg_count = 0;
1882 	int ret = 0;
1883 
1884 	spin_lock(&dev->dev_reservation_lock);
1885 	spin_lock(&dev->t10_pr.registration_lock);
1886 	/*
1887 	 * Walk the registration list..
1888 	 */
1889 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1890 			pr_reg_list) {
1891 
1892 		tmp[0] = '\0';
1893 		isid_buf[0] = '\0';
1894 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1895 		/*
1896 		 * Write out any ISID value to APTPL metadata that was included
1897 		 * in the original registration.
1898 		 */
1899 		if (pr_reg->isid_present_at_reg)
1900 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1901 					pr_reg->pr_reg_isid);
1902 		/*
1903 		 * Include special metadata if the pr_reg matches the
1904 		 * reservation holder.
1905 		 */
1906 		if (dev->dev_pr_res_holder == pr_reg) {
1907 			snprintf(tmp, 512, "PR_REG_START: %d"
1908 				"\ninitiator_fabric=%s\n"
1909 				"initiator_node=%s\n%s"
1910 				"sa_res_key=%llu\n"
1911 				"res_holder=1\nres_type=%02x\n"
1912 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1913 				"mapped_lun=%llu\n", reg_count,
1914 				tpg->se_tpg_tfo->fabric_name,
1915 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1916 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1917 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1918 				pr_reg->pr_res_mapped_lun);
1919 		} else {
1920 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1921 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1922 				"sa_res_key=%llu\nres_holder=0\n"
1923 				"res_all_tg_pt=%d\nmapped_lun=%llu\n",
1924 				reg_count, tpg->se_tpg_tfo->fabric_name,
1925 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1926 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1927 				pr_reg->pr_res_mapped_lun);
1928 		}
1929 
1930 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1931 			pr_err("Unable to update renaming APTPL metadata,"
1932 			       " reallocating larger buffer\n");
1933 			ret = -EMSGSIZE;
1934 			goto out;
1935 		}
1936 		len += sprintf(buf+len, "%s", tmp);
1937 
1938 		/*
1939 		 * Include information about the associated SCSI target port.
1940 		 */
1941 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1942 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%llu\nPR_REG_END:"
1943 			" %d\n", tpg->se_tpg_tfo->fabric_name,
1944 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1945 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1946 			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
1947 			reg_count);
1948 
1949 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1950 			pr_err("Unable to update renaming APTPL metadata,"
1951 			       " reallocating larger buffer\n");
1952 			ret = -EMSGSIZE;
1953 			goto out;
1954 		}
1955 		len += sprintf(buf+len, "%s", tmp);
1956 		reg_count++;
1957 	}
1958 
1959 	if (!reg_count)
1960 		len += sprintf(buf+len, "No Registrations or Reservations");
1961 
1962 out:
1963 	spin_unlock(&dev->t10_pr.registration_lock);
1964 	spin_unlock(&dev->dev_reservation_lock);
1965 
1966 	return ret;
1967 }
1968 
1969 static int __core_scsi3_write_aptpl_to_file(
1970 	struct se_device *dev,
1971 	unsigned char *buf)
1972 {
1973 	struct t10_wwn *wwn = &dev->t10_wwn;
1974 	struct file *file;
1975 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1976 	char *path;
1977 	u32 pr_aptpl_buf_len;
1978 	int ret;
1979 	loff_t pos = 0;
1980 
1981 	path = kasprintf(GFP_KERNEL, "%s/pr/aptpl_%s", db_root,
1982 			&wwn->unit_serial[0]);
1983 	if (!path)
1984 		return -ENOMEM;
1985 
1986 	file = filp_open(path, flags, 0600);
1987 	if (IS_ERR(file)) {
1988 		pr_err("filp_open(%s) for APTPL metadata"
1989 			" failed\n", path);
1990 		kfree(path);
1991 		return PTR_ERR(file);
1992 	}
1993 
1994 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1995 
1996 	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);
1997 
1998 	if (ret < 0)
1999 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2000 	fput(file);
2001 	kfree(path);
2002 
2003 	return (ret < 0) ? -EIO : 0;
2004 }
2005 
2006 /*
2007  * Clear the APTPL metadata if APTPL has been disabled, otherwise
2008  * write out the updated metadata to struct file for this SCSI device.
2009  */
2010 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
2011 {
2012 	unsigned char *buf;
2013 	int rc, len = PR_APTPL_BUF_LEN;
2014 
2015 	if (!aptpl) {
2016 		char *null_buf = "No Registrations or Reservations\n";
2017 
2018 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
2019 		dev->t10_pr.pr_aptpl_active = 0;
2020 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
2021 
2022 		if (rc)
2023 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2024 
2025 		return 0;
2026 	}
2027 retry:
2028 	buf = vzalloc(len);
2029 	if (!buf)
2030 		return TCM_OUT_OF_RESOURCES;
2031 
2032 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
2033 	if (rc < 0) {
2034 		vfree(buf);
2035 		len *= 2;
2036 		goto retry;
2037 	}
2038 
2039 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2040 	if (rc != 0) {
2041 		pr_err("SPC-3 PR: Could not update APTPL\n");
2042 		vfree(buf);
2043 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2044 	}
2045 	dev->t10_pr.pr_aptpl_active = 1;
2046 	vfree(buf);
2047 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2048 	return 0;
2049 }
2050 
2051 static sense_reason_t
2052 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2053 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2054 {
2055 	struct se_session *se_sess = cmd->se_sess;
2056 	struct se_device *dev = cmd->se_dev;
2057 	struct se_lun *se_lun = cmd->se_lun;
2058 	struct se_portal_group *se_tpg;
2059 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2060 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2061 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2062 	sense_reason_t ret = TCM_NO_SENSE;
2063 	int pr_holder = 0, type;
2064 
2065 	if (!se_sess || !se_lun) {
2066 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2067 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2068 	}
2069 	se_tpg = se_sess->se_tpg;
2070 
2071 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2072 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2073 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2074 				PR_REG_ISID_LEN);
2075 		isid_ptr = &isid_buf[0];
2076 	}
2077 	/*
2078 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2079 	 */
2080 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2081 	if (!pr_reg) {
2082 		if (res_key) {
2083 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2084 				" for SA REGISTER, returning CONFLICT\n");
2085 			return TCM_RESERVATION_CONFLICT;
2086 		}
2087 		/*
2088 		 * Do nothing but return GOOD status.
2089 		 */
2090 		if (!sa_res_key)
2091 			return 0;
2092 
2093 		if (!spec_i_pt) {
2094 			/*
2095 			 * Perform the Service Action REGISTER on the Initiator
2096 			 * Port Endpoint that the PRO was received from on the
2097 			 * Logical Unit of the SCSI device server.
2098 			 */
2099 			if (core_scsi3_alloc_registration(cmd->se_dev,
2100 					se_sess->se_node_acl, cmd->se_lun,
2101 					NULL, cmd->orig_fe_lun, isid_ptr,
2102 					sa_res_key, all_tg_pt, aptpl,
2103 					register_type, 0)) {
2104 				pr_err("Unable to allocate"
2105 					" struct t10_pr_registration\n");
2106 				return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
2107 			}
2108 		} else {
2109 			/*
2110 			 * Register both the Initiator port that received
2111 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2112 			 * TransportID from Parameter list and loop through
2113 			 * fabric dependent parameter list while calling
2114 			 * logic from of core_scsi3_alloc_registration() for
2115 			 * each TransportID provided SCSI Initiator Port/Device
2116 			 */
2117 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2118 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2119 			if (ret != 0)
2120 				return ret;
2121 		}
2122 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2123 	}
2124 
2125 	/* ok, existing registration */
2126 
2127 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2128 		pr_err("SPC-3 PR REGISTER: Received"
2129 		       " res_key: 0x%016Lx does not match"
2130 		       " existing SA REGISTER res_key:"
2131 		       " 0x%016Lx\n", res_key,
2132 		       pr_reg->pr_res_key);
2133 		ret = TCM_RESERVATION_CONFLICT;
2134 		goto out;
2135 	}
2136 
2137 	if (spec_i_pt) {
2138 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2139 			" set on a registered nexus\n");
2140 		ret = TCM_INVALID_PARAMETER_LIST;
2141 		goto out;
2142 	}
2143 
2144 	/*
2145 	 * An existing ALL_TG_PT=1 registration being released
2146 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2147 	 */
2148 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2149 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2150 			" registration exists, but ALL_TG_PT=1 bit not"
2151 			" present in received PROUT\n");
2152 		ret = TCM_INVALID_CDB_FIELD;
2153 		goto out;
2154 	}
2155 
2156 	/*
2157 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2158 	 */
2159 	if (sa_res_key) {
2160 		/*
2161 		 * Increment PRgeneration counter for struct se_device"
2162 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2163 		 * READ_KEYS service action.
2164 		 */
2165 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2166 		pr_reg->pr_res_key = sa_res_key;
2167 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2168 			 " Key for %s to: 0x%016Lx PRgeneration:"
2169 			 " 0x%08x\n", cmd->se_tfo->fabric_name,
2170 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2171 			 pr_reg->pr_reg_nacl->initiatorname,
2172 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2173 
2174 	} else {
2175 		/*
2176 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2177 		 */
2178 		type = pr_reg->pr_res_type;
2179 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2180 							      pr_reg);
2181 		if (pr_holder < 0) {
2182 			ret = TCM_RESERVATION_CONFLICT;
2183 			goto out;
2184 		}
2185 
2186 		spin_lock(&pr_tmpl->registration_lock);
2187 		/*
2188 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2189 		 * and matching pr_res_key.
2190 		 */
2191 		if (pr_reg->pr_reg_all_tg_pt) {
2192 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2193 					&pr_tmpl->registration_list,
2194 					pr_reg_list) {
2195 
2196 				if (!pr_reg_p->pr_reg_all_tg_pt)
2197 					continue;
2198 				if (pr_reg_p->pr_res_key != res_key)
2199 					continue;
2200 				if (pr_reg == pr_reg_p)
2201 					continue;
2202 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2203 					   pr_reg_p->pr_reg_nacl->initiatorname))
2204 					continue;
2205 
2206 				__core_scsi3_free_registration(dev,
2207 						pr_reg_p, NULL, 0);
2208 			}
2209 		}
2210 
2211 		/*
2212 		 * Release the calling I_T Nexus registration now..
2213 		 */
2214 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2215 		pr_reg = NULL;
2216 
2217 		/*
2218 		 * From spc4r17, section 5.7.11.3 Unregistering
2219 		 *
2220 		 * If the persistent reservation is a registrants only
2221 		 * type, the device server shall establish a unit
2222 		 * attention condition for the initiator port associated
2223 		 * with every registered I_T nexus except for the I_T
2224 		 * nexus on which the PERSISTENT RESERVE OUT command was
2225 		 * received, with the additional sense code set to
2226 		 * RESERVATIONS RELEASED.
2227 		 */
2228 		if (pr_holder &&
2229 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2230 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2231 			list_for_each_entry(pr_reg_p,
2232 					&pr_tmpl->registration_list,
2233 					pr_reg_list) {
2234 
2235 				target_ua_allocate_lun(
2236 					pr_reg_p->pr_reg_nacl,
2237 					pr_reg_p->pr_res_mapped_lun,
2238 					0x2A,
2239 					ASCQ_2AH_RESERVATIONS_RELEASED);
2240 			}
2241 		}
2242 
2243 		spin_unlock(&pr_tmpl->registration_lock);
2244 	}
2245 
2246 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2247 
2248 out:
2249 	if (pr_reg)
2250 		core_scsi3_put_pr_reg(pr_reg);
2251 	return ret;
2252 }
2253 
2254 unsigned char *core_scsi3_pr_dump_type(int type)
2255 {
2256 	switch (type) {
2257 	case PR_TYPE_WRITE_EXCLUSIVE:
2258 		return "Write Exclusive Access";
2259 	case PR_TYPE_EXCLUSIVE_ACCESS:
2260 		return "Exclusive Access";
2261 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2262 		return "Write Exclusive Access, Registrants Only";
2263 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2264 		return "Exclusive Access, Registrants Only";
2265 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2266 		return "Write Exclusive Access, All Registrants";
2267 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2268 		return "Exclusive Access, All Registrants";
2269 	default:
2270 		break;
2271 	}
2272 
2273 	return "Unknown SPC-3 PR Type";
2274 }
2275 
2276 static sense_reason_t
2277 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2278 {
2279 	struct se_device *dev = cmd->se_dev;
2280 	struct se_session *se_sess = cmd->se_sess;
2281 	struct se_lun *se_lun = cmd->se_lun;
2282 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2283 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2284 	char i_buf[PR_REG_ISID_ID_LEN];
2285 	sense_reason_t ret;
2286 
2287 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2288 
2289 	if (!se_sess || !se_lun) {
2290 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2291 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2292 	}
2293 	/*
2294 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2295 	 */
2296 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2297 				se_sess);
2298 	if (!pr_reg) {
2299 		pr_err("SPC-3 PR: Unable to locate"
2300 			" PR_REGISTERED *pr_reg for RESERVE\n");
2301 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2302 	}
2303 	/*
2304 	 * From spc4r17 Section 5.7.9: Reserving:
2305 	 *
2306 	 * An application client creates a persistent reservation by issuing
2307 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2308 	 * a registered I_T nexus with the following parameters:
2309 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2310 	 * 	 registered with the logical unit for the I_T nexus; and
2311 	 */
2312 	if (res_key != pr_reg->pr_res_key) {
2313 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2314 			" does not match existing SA REGISTER res_key:"
2315 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2316 		ret = TCM_RESERVATION_CONFLICT;
2317 		goto out_put_pr_reg;
2318 	}
2319 	/*
2320 	 * From spc4r17 Section 5.7.9: Reserving:
2321 	 *
2322 	 * From above:
2323 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2324 	 *     being created.
2325 	 *
2326 	 * Only one persistent reservation is allowed at a time per logical unit
2327 	 * and that persistent reservation has a scope of LU_SCOPE.
2328 	 */
2329 	if (scope != PR_SCOPE_LU_SCOPE) {
2330 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2331 		ret = TCM_INVALID_PARAMETER_LIST;
2332 		goto out_put_pr_reg;
2333 	}
2334 	/*
2335 	 * See if we have an existing PR reservation holder pointer at
2336 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2337 	 * *pr_res_holder.
2338 	 */
2339 	spin_lock(&dev->dev_reservation_lock);
2340 	pr_res_holder = dev->dev_pr_res_holder;
2341 	if (pr_res_holder) {
2342 		/*
2343 		 * From spc4r17 Section 5.7.9: Reserving:
2344 		 *
2345 		 * If the device server receives a PERSISTENT RESERVE OUT
2346 		 * command from an I_T nexus other than a persistent reservation
2347 		 * holder (see 5.7.10) that attempts to create a persistent
2348 		 * reservation when a persistent reservation already exists for
2349 		 * the logical unit, then the command shall be completed with
2350 		 * RESERVATION CONFLICT status.
2351 		 */
2352 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2353 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2354 			pr_err("SPC-3 PR: Attempted RESERVE from"
2355 				" [%s]: %s while reservation already held by"
2356 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2357 				cmd->se_tfo->fabric_name,
2358 				se_sess->se_node_acl->initiatorname,
2359 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2360 				pr_res_holder->pr_reg_nacl->initiatorname);
2361 
2362 			spin_unlock(&dev->dev_reservation_lock);
2363 			ret = TCM_RESERVATION_CONFLICT;
2364 			goto out_put_pr_reg;
2365 		}
2366 		/*
2367 		 * From spc4r17 Section 5.7.9: Reserving:
2368 		 *
2369 		 * If a persistent reservation holder attempts to modify the
2370 		 * type or scope of an existing persistent reservation, the
2371 		 * command shall be completed with RESERVATION CONFLICT status.
2372 		 */
2373 		if ((pr_res_holder->pr_res_type != type) ||
2374 		    (pr_res_holder->pr_res_scope != scope)) {
2375 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2376 			pr_err("SPC-3 PR: Attempted RESERVE from"
2377 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2378 				" while reservation already held by [%s]: %s,"
2379 				" returning RESERVATION_CONFLICT\n",
2380 				cmd->se_tfo->fabric_name,
2381 				se_sess->se_node_acl->initiatorname,
2382 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2383 				pr_res_holder->pr_reg_nacl->initiatorname);
2384 
2385 			spin_unlock(&dev->dev_reservation_lock);
2386 			ret = TCM_RESERVATION_CONFLICT;
2387 			goto out_put_pr_reg;
2388 		}
2389 		/*
2390 		 * From spc4r17 Section 5.7.9: Reserving:
2391 		 *
2392 		 * If the device server receives a PERSISTENT RESERVE OUT
2393 		 * command with RESERVE service action where the TYPE field and
2394 		 * the SCOPE field contain the same values as the existing type
2395 		 * and scope from a persistent reservation holder, it shall not
2396 		 * make any change to the existing persistent reservation and
2397 		 * shall completethe command with GOOD status.
2398 		 */
2399 		spin_unlock(&dev->dev_reservation_lock);
2400 		ret = 0;
2401 		goto out_put_pr_reg;
2402 	}
2403 	/*
2404 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2405 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2406 	 */
2407 	pr_reg->pr_res_scope = scope;
2408 	pr_reg->pr_res_type = type;
2409 	pr_reg->pr_res_holder = 1;
2410 	dev->dev_pr_res_holder = pr_reg;
2411 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2412 
2413 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2414 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2415 		cmd->se_tfo->fabric_name, core_scsi3_pr_dump_type(type),
2416 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2417 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2418 			cmd->se_tfo->fabric_name,
2419 			se_sess->se_node_acl->initiatorname,
2420 			i_buf);
2421 	spin_unlock(&dev->dev_reservation_lock);
2422 
2423 	if (pr_tmpl->pr_aptpl_active)
2424 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2425 
2426 	ret = 0;
2427 out_put_pr_reg:
2428 	core_scsi3_put_pr_reg(pr_reg);
2429 	return ret;
2430 }
2431 
2432 static sense_reason_t
2433 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2434 		u64 res_key)
2435 {
2436 	switch (type) {
2437 	case PR_TYPE_WRITE_EXCLUSIVE:
2438 	case PR_TYPE_EXCLUSIVE_ACCESS:
2439 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2440 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2441 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2442 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2443 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2444 	default:
2445 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2446 			" 0x%02x\n", type);
2447 		return TCM_INVALID_CDB_FIELD;
2448 	}
2449 }
2450 
2451 static void __core_scsi3_complete_pro_release(
2452 	struct se_device *dev,
2453 	struct se_node_acl *se_nacl,
2454 	struct t10_pr_registration *pr_reg,
2455 	int explicit,
2456 	int unreg)
2457 {
2458 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2459 	char i_buf[PR_REG_ISID_ID_LEN];
2460 	int pr_res_type = 0, pr_res_scope = 0;
2461 
2462 	lockdep_assert_held(&dev->dev_reservation_lock);
2463 
2464 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2465 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2466 	/*
2467 	 * Go ahead and release the current PR reservation holder.
2468 	 * If an All Registrants reservation is currently active and
2469 	 * a unregister operation is requested, replace the current
2470 	 * dev_pr_res_holder with another active registration.
2471 	 */
2472 	if (dev->dev_pr_res_holder) {
2473 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2474 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2475 		dev->dev_pr_res_holder->pr_res_type = 0;
2476 		dev->dev_pr_res_holder->pr_res_scope = 0;
2477 		dev->dev_pr_res_holder->pr_res_holder = 0;
2478 		dev->dev_pr_res_holder = NULL;
2479 	}
2480 	if (!unreg)
2481 		goto out;
2482 
2483 	spin_lock(&dev->t10_pr.registration_lock);
2484 	list_del_init(&pr_reg->pr_reg_list);
2485 	/*
2486 	 * If the I_T nexus is a reservation holder, the persistent reservation
2487 	 * is of an all registrants type, and the I_T nexus is the last remaining
2488 	 * registered I_T nexus, then the device server shall also release the
2489 	 * persistent reservation.
2490 	 */
2491 	if (!list_empty(&dev->t10_pr.registration_list) &&
2492 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2493 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2494 		dev->dev_pr_res_holder =
2495 			list_entry(dev->t10_pr.registration_list.next,
2496 				   struct t10_pr_registration, pr_reg_list);
2497 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2498 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2499 		dev->dev_pr_res_holder->pr_res_holder = 1;
2500 	}
2501 	spin_unlock(&dev->t10_pr.registration_lock);
2502 out:
2503 	if (!dev->dev_pr_res_holder) {
2504 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2505 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2506 			tfo->fabric_name, (explicit) ? "explicit" :
2507 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2508 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2509 	}
2510 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2511 		tfo->fabric_name, se_nacl->initiatorname,
2512 		i_buf);
2513 	/*
2514 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2515 	 */
2516 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2517 }
2518 
2519 static sense_reason_t
2520 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2521 		u64 res_key)
2522 {
2523 	struct se_device *dev = cmd->se_dev;
2524 	struct se_session *se_sess = cmd->se_sess;
2525 	struct se_lun *se_lun = cmd->se_lun;
2526 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2527 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2528 	sense_reason_t ret = 0;
2529 
2530 	if (!se_sess || !se_lun) {
2531 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2532 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2533 	}
2534 	/*
2535 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2536 	 */
2537 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2538 	if (!pr_reg) {
2539 		pr_err("SPC-3 PR: Unable to locate"
2540 			" PR_REGISTERED *pr_reg for RELEASE\n");
2541 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2542 	}
2543 	/*
2544 	 * From spc4r17 Section 5.7.11.2 Releasing:
2545 	 *
2546 	 * If there is no persistent reservation or in response to a persistent
2547 	 * reservation release request from a registered I_T nexus that is not a
2548 	 * persistent reservation holder (see 5.7.10), the device server shall
2549 	 * do the following:
2550 	 *
2551 	 *     a) Not release the persistent reservation, if any;
2552 	 *     b) Not remove any registrations; and
2553 	 *     c) Complete the command with GOOD status.
2554 	 */
2555 	spin_lock(&dev->dev_reservation_lock);
2556 	pr_res_holder = dev->dev_pr_res_holder;
2557 	if (!pr_res_holder) {
2558 		/*
2559 		 * No persistent reservation, return GOOD status.
2560 		 */
2561 		spin_unlock(&dev->dev_reservation_lock);
2562 		goto out_put_pr_reg;
2563 	}
2564 
2565 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2566 		/*
2567 		 * Release request from a registered I_T nexus that is not a
2568 		 * persistent reservation holder. return GOOD status.
2569 		 */
2570 		spin_unlock(&dev->dev_reservation_lock);
2571 		goto out_put_pr_reg;
2572 	}
2573 
2574 	/*
2575 	 * From spc4r17 Section 5.7.11.2 Releasing:
2576 	 *
2577 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2578 	 * release a persistent reservation.
2579 	 *
2580 	 * An application client releases the persistent reservation by issuing
2581 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2582 	 * an I_T nexus that is a persistent reservation holder with the
2583 	 * following parameters:
2584 	 *
2585 	 *     a) RESERVATION KEY field set to the value of the reservation key
2586 	 *	  that is registered with the logical unit for the I_T nexus;
2587 	 */
2588 	if (res_key != pr_reg->pr_res_key) {
2589 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2590 			" does not match existing SA REGISTER res_key:"
2591 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2592 		spin_unlock(&dev->dev_reservation_lock);
2593 		ret = TCM_RESERVATION_CONFLICT;
2594 		goto out_put_pr_reg;
2595 	}
2596 	/*
2597 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2598 	 *
2599 	 * b) TYPE field and SCOPE field set to match the persistent
2600 	 *    reservation being released.
2601 	 */
2602 	if ((pr_res_holder->pr_res_type != type) ||
2603 	    (pr_res_holder->pr_res_scope != scope)) {
2604 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2605 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2606 			" reservation from [%s]: %s with different TYPE "
2607 			"and/or SCOPE  while reservation already held by"
2608 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2609 			cmd->se_tfo->fabric_name,
2610 			se_sess->se_node_acl->initiatorname,
2611 			pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2612 			pr_res_holder->pr_reg_nacl->initiatorname);
2613 
2614 		spin_unlock(&dev->dev_reservation_lock);
2615 		ret = TCM_RESERVATION_CONFLICT;
2616 		goto out_put_pr_reg;
2617 	}
2618 	/*
2619 	 * In response to a persistent reservation release request from the
2620 	 * persistent reservation holder the device server shall perform a
2621 	 * release by doing the following as an uninterrupted series of actions:
2622 	 * a) Release the persistent reservation;
2623 	 * b) Not remove any registration(s);
2624 	 * c) If the released persistent reservation is a registrants only type
2625 	 * or all registrants type persistent reservation,
2626 	 *    the device server shall establish a unit attention condition for
2627 	 *    the initiator port associated with every regis-
2628 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2629 	 *    RESERVE OUT command with RELEASE service action was received,
2630 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2631 	 * d) If the persistent reservation is of any other type, the device
2632 	 *    server shall not establish a unit attention condition.
2633 	 */
2634 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2635 					  pr_reg, 1, 0);
2636 
2637 	spin_unlock(&dev->dev_reservation_lock);
2638 
2639 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2640 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2641 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2642 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2643 		/*
2644 		 * If no UNIT ATTENTION conditions will be established for
2645 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2646 		 * go ahead and check for APTPL=1 update+write below
2647 		 */
2648 		goto write_aptpl;
2649 	}
2650 
2651 	spin_lock(&pr_tmpl->registration_lock);
2652 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2653 			pr_reg_list) {
2654 		/*
2655 		 * Do not establish a UNIT ATTENTION condition
2656 		 * for the calling I_T Nexus
2657 		 */
2658 		if (pr_reg_p == pr_reg)
2659 			continue;
2660 
2661 		target_ua_allocate_lun(pr_reg_p->pr_reg_nacl,
2662 				pr_reg_p->pr_res_mapped_lun,
2663 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2664 	}
2665 	spin_unlock(&pr_tmpl->registration_lock);
2666 
2667 write_aptpl:
2668 	if (pr_tmpl->pr_aptpl_active)
2669 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2670 
2671 out_put_pr_reg:
2672 	core_scsi3_put_pr_reg(pr_reg);
2673 	return ret;
2674 }
2675 
2676 static sense_reason_t
2677 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2678 {
2679 	struct se_device *dev = cmd->se_dev;
2680 	struct se_node_acl *pr_reg_nacl;
2681 	struct se_session *se_sess = cmd->se_sess;
2682 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2683 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2684 	u64 pr_res_mapped_lun = 0;
2685 	int calling_it_nexus = 0;
2686 	/*
2687 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2688 	 */
2689 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2690 			se_sess->se_node_acl, se_sess);
2691 	if (!pr_reg_n) {
2692 		pr_err("SPC-3 PR: Unable to locate"
2693 			" PR_REGISTERED *pr_reg for CLEAR\n");
2694 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2695 	}
2696 	/*
2697 	 * From spc4r17 section 5.7.11.6, Clearing:
2698 	 *
2699 	 * Any application client may release the persistent reservation and
2700 	 * remove all registrations from a device server by issuing a
2701 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2702 	 * registered I_T nexus with the following parameter:
2703 	 *
2704 	 *	a) RESERVATION KEY field set to the value of the reservation key
2705 	 * 	   that is registered with the logical unit for the I_T nexus.
2706 	 */
2707 	if (res_key != pr_reg_n->pr_res_key) {
2708 		pr_err("SPC-3 PR REGISTER: Received"
2709 			" res_key: 0x%016Lx does not match"
2710 			" existing SA REGISTER res_key:"
2711 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2712 		core_scsi3_put_pr_reg(pr_reg_n);
2713 		return TCM_RESERVATION_CONFLICT;
2714 	}
2715 	/*
2716 	 * a) Release the persistent reservation, if any;
2717 	 */
2718 	spin_lock(&dev->dev_reservation_lock);
2719 	pr_res_holder = dev->dev_pr_res_holder;
2720 	if (pr_res_holder) {
2721 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2722 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2723 						  pr_res_holder, 0, 0);
2724 	}
2725 	spin_unlock(&dev->dev_reservation_lock);
2726 	/*
2727 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2728 	 */
2729 	spin_lock(&pr_tmpl->registration_lock);
2730 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2731 			&pr_tmpl->registration_list, pr_reg_list) {
2732 
2733 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2734 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2735 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2736 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2737 					calling_it_nexus);
2738 		/*
2739 		 * e) Establish a unit attention condition for the initiator
2740 		 *    port associated with every registered I_T nexus other
2741 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2742 		 *    command with CLEAR service action was received, with the
2743 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2744 		 */
2745 		if (!calling_it_nexus)
2746 			target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun,
2747 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2748 	}
2749 	spin_unlock(&pr_tmpl->registration_lock);
2750 
2751 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2752 		cmd->se_tfo->fabric_name);
2753 
2754 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2755 
2756 	core_scsi3_pr_generation(dev);
2757 	return 0;
2758 }
2759 
2760 static void __core_scsi3_complete_pro_preempt(
2761 	struct se_device *dev,
2762 	struct t10_pr_registration *pr_reg,
2763 	struct list_head *preempt_and_abort_list,
2764 	int type,
2765 	int scope,
2766 	enum preempt_type preempt_type)
2767 {
2768 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2769 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2770 	char i_buf[PR_REG_ISID_ID_LEN];
2771 
2772 	lockdep_assert_held(&dev->dev_reservation_lock);
2773 
2774 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2775 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2776 	/*
2777 	 * Do an implicit RELEASE of the existing reservation.
2778 	 */
2779 	if (dev->dev_pr_res_holder)
2780 		__core_scsi3_complete_pro_release(dev, nacl,
2781 						  dev->dev_pr_res_holder, 0, 0);
2782 
2783 	dev->dev_pr_res_holder = pr_reg;
2784 	pr_reg->pr_res_holder = 1;
2785 	pr_reg->pr_res_type = type;
2786 	pr_reg->pr_res_scope = scope;
2787 
2788 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2789 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2790 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2791 		core_scsi3_pr_dump_type(type),
2792 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2793 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2794 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2795 		nacl->initiatorname, i_buf);
2796 	/*
2797 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2798 	 * struct t10_pr_registration to the list that will be compared
2799 	 * against received CDBs..
2800 	 */
2801 	if (preempt_and_abort_list)
2802 		list_add_tail(&pr_reg->pr_reg_abort_list,
2803 				preempt_and_abort_list);
2804 }
2805 
2806 static void core_scsi3_release_preempt_and_abort(
2807 	struct list_head *preempt_and_abort_list,
2808 	struct t10_pr_registration *pr_reg_holder)
2809 {
2810 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2811 
2812 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2813 				pr_reg_abort_list) {
2814 
2815 		list_del(&pr_reg->pr_reg_abort_list);
2816 		if (pr_reg_holder == pr_reg)
2817 			continue;
2818 		if (pr_reg->pr_res_holder) {
2819 			pr_warn("pr_reg->pr_res_holder still set\n");
2820 			continue;
2821 		}
2822 
2823 		pr_reg->pr_reg_deve = NULL;
2824 		pr_reg->pr_reg_nacl = NULL;
2825 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2826 	}
2827 }
2828 
2829 static sense_reason_t
2830 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2831 		u64 sa_res_key, enum preempt_type preempt_type)
2832 {
2833 	struct se_device *dev = cmd->se_dev;
2834 	struct se_node_acl *pr_reg_nacl;
2835 	struct se_session *se_sess = cmd->se_sess;
2836 	LIST_HEAD(preempt_and_abort_list);
2837 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2838 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2839 	u64 pr_res_mapped_lun = 0;
2840 	int all_reg = 0, calling_it_nexus = 0;
2841 	bool sa_res_key_unmatched = sa_res_key != 0;
2842 	int prh_type = 0, prh_scope = 0;
2843 
2844 	if (!se_sess)
2845 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2846 
2847 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2848 				se_sess);
2849 	if (!pr_reg_n) {
2850 		pr_err("SPC-3 PR: Unable to locate"
2851 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2852 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2853 		return TCM_RESERVATION_CONFLICT;
2854 	}
2855 	if (pr_reg_n->pr_res_key != res_key) {
2856 		core_scsi3_put_pr_reg(pr_reg_n);
2857 		return TCM_RESERVATION_CONFLICT;
2858 	}
2859 	if (scope != PR_SCOPE_LU_SCOPE) {
2860 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2861 		core_scsi3_put_pr_reg(pr_reg_n);
2862 		return TCM_INVALID_PARAMETER_LIST;
2863 	}
2864 
2865 	spin_lock(&dev->dev_reservation_lock);
2866 	pr_res_holder = dev->dev_pr_res_holder;
2867 	if (pr_res_holder &&
2868 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2869 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2870 		all_reg = 1;
2871 
2872 	if (!all_reg && !sa_res_key) {
2873 		spin_unlock(&dev->dev_reservation_lock);
2874 		core_scsi3_put_pr_reg(pr_reg_n);
2875 		return TCM_INVALID_PARAMETER_LIST;
2876 	}
2877 	/*
2878 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2879 	 *
2880 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2881 	 * persistent reservation holder or there is no persistent reservation
2882 	 * holder (i.e., there is no persistent reservation), then the device
2883 	 * server shall perform a preempt by doing the following in an
2884 	 * uninterrupted series of actions. (See below..)
2885 	 */
2886 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2887 		/*
2888 		 * No existing or SA Reservation Key matching reservations..
2889 		 *
2890 		 * PROUT SA PREEMPT with All Registrant type reservations are
2891 		 * allowed to be processed without a matching SA Reservation Key
2892 		 */
2893 		spin_lock(&pr_tmpl->registration_lock);
2894 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2895 				&pr_tmpl->registration_list, pr_reg_list) {
2896 			/*
2897 			 * Removing of registrations in non all registrants
2898 			 * type reservations without a matching SA reservation
2899 			 * key.
2900 			 *
2901 			 * a) Remove the registrations for all I_T nexuses
2902 			 *    specified by the SERVICE ACTION RESERVATION KEY
2903 			 *    field;
2904 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2905 			 * c) Process tasks as defined in 5.7.1; and
2906 			 * d) Establish a unit attention condition for the
2907 			 *    initiator port associated with every I_T nexus
2908 			 *    that lost its registration other than the I_T
2909 			 *    nexus on which the PERSISTENT RESERVE OUT command
2910 			 *    was received, with the additional sense code set
2911 			 *    to REGISTRATIONS PREEMPTED.
2912 			 */
2913 			if (!all_reg) {
2914 				if (pr_reg->pr_res_key != sa_res_key)
2915 					continue;
2916 				sa_res_key_unmatched = false;
2917 
2918 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2919 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2920 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2921 				__core_scsi3_free_registration(dev, pr_reg,
2922 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2923 						NULL, calling_it_nexus);
2924 			} else {
2925 				/*
2926 				 * Case for any existing all registrants type
2927 				 * reservation, follow logic in spc4r17 section
2928 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2929 				 *
2930 				 * For a ZERO SA Reservation key, release
2931 				 * all other registrations and do an implicit
2932 				 * release of active persistent reservation.
2933 				 *
2934 				 * For a non-ZERO SA Reservation key, only
2935 				 * release the matching reservation key from
2936 				 * registrations.
2937 				 */
2938 				if ((sa_res_key) &&
2939 				     (pr_reg->pr_res_key != sa_res_key))
2940 					continue;
2941 				sa_res_key_unmatched = false;
2942 
2943 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2944 				if (calling_it_nexus)
2945 					continue;
2946 
2947 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2948 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2949 				__core_scsi3_free_registration(dev, pr_reg,
2950 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2951 						NULL, 0);
2952 			}
2953 			if (!calling_it_nexus)
2954 				target_ua_allocate_lun(pr_reg_nacl,
2955 					pr_res_mapped_lun, 0x2A,
2956 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2957 		}
2958 		spin_unlock(&pr_tmpl->registration_lock);
2959 		/*
2960 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2961 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2962 		 * RESERVATION KEY field to a value that does not match any
2963 		 * registered reservation key, then the device server shall
2964 		 * complete the command with RESERVATION CONFLICT status.
2965 		 */
2966 		if (sa_res_key_unmatched) {
2967 			spin_unlock(&dev->dev_reservation_lock);
2968 			core_scsi3_put_pr_reg(pr_reg_n);
2969 			return TCM_RESERVATION_CONFLICT;
2970 		}
2971 		/*
2972 		 * For an existing all registrants type reservation
2973 		 * with a zero SA rservation key, preempt the existing
2974 		 * reservation with the new PR type and scope.
2975 		 */
2976 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2977 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2978 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2979 				type, scope, preempt_type);
2980 
2981 			if (preempt_type == PREEMPT_AND_ABORT)
2982 				core_scsi3_release_preempt_and_abort(
2983 					&preempt_and_abort_list, pr_reg_n);
2984 		}
2985 		spin_unlock(&dev->dev_reservation_lock);
2986 
2987 		if (pr_tmpl->pr_aptpl_active)
2988 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2989 
2990 		core_scsi3_put_pr_reg(pr_reg_n);
2991 		core_scsi3_pr_generation(cmd->se_dev);
2992 		return 0;
2993 	}
2994 	/*
2995 	 * The PREEMPTing SA reservation key matches that of the
2996 	 * existing persistent reservation, first, we check if
2997 	 * we are preempting our own reservation.
2998 	 * From spc4r17, section 5.7.11.4.3 Preempting
2999 	 * persistent reservations and registration handling
3000 	 *
3001 	 * If an all registrants persistent reservation is not
3002 	 * present, it is not an error for the persistent
3003 	 * reservation holder to preempt itself (i.e., a
3004 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3005 	 * or a PREEMPT AND ABORT service action with the
3006 	 * SERVICE ACTION RESERVATION KEY value equal to the
3007 	 * persistent reservation holder's reservation key that
3008 	 * is received from the persistent reservation holder).
3009 	 * In that case, the device server shall establish the
3010 	 * new persistent reservation and maintain the
3011 	 * registration.
3012 	 */
3013 	prh_type = pr_res_holder->pr_res_type;
3014 	prh_scope = pr_res_holder->pr_res_scope;
3015 	/*
3016 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3017 	 * persistent reservation holder (see 5.7.10), the device
3018 	 * server shall perform a preempt by doing the following as
3019 	 * an uninterrupted series of actions:
3020 	 *
3021 	 * a) Release the persistent reservation for the holder
3022 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3023 	 */
3024 	if (pr_reg_n != pr_res_holder)
3025 		__core_scsi3_complete_pro_release(dev,
3026 						  pr_res_holder->pr_reg_nacl,
3027 						  dev->dev_pr_res_holder, 0, 0);
3028 	/*
3029 	 * b) Remove the registrations for all I_T nexuses identified
3030 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3031 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3032 	 *    OUT command. If an all registrants persistent reservation
3033 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3034 	 *    is set to zero, then all registrations shall be removed
3035 	 *    except for that of the I_T nexus that is being used for
3036 	 *    the PERSISTENT RESERVE OUT command;
3037 	 */
3038 	spin_lock(&pr_tmpl->registration_lock);
3039 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3040 			&pr_tmpl->registration_list, pr_reg_list) {
3041 
3042 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3043 		if (calling_it_nexus)
3044 			continue;
3045 
3046 		if (pr_reg->pr_res_key != sa_res_key)
3047 			continue;
3048 
3049 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3050 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3051 		__core_scsi3_free_registration(dev, pr_reg,
3052 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3053 				calling_it_nexus);
3054 		/*
3055 		 * e) Establish a unit attention condition for the initiator
3056 		 *    port associated with every I_T nexus that lost its
3057 		 *    persistent reservation and/or registration, with the
3058 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3059 		 */
3060 		target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3061 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3062 	}
3063 	spin_unlock(&pr_tmpl->registration_lock);
3064 	/*
3065 	 * c) Establish a persistent reservation for the preempting
3066 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3067 	 */
3068 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3069 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3070 			type, scope, preempt_type);
3071 	/*
3072 	 * d) Process tasks as defined in 5.7.1;
3073 	 * e) See above..
3074 	 * f) If the type or scope has changed, then for every I_T nexus
3075 	 *    whose reservation key was not removed, except for the I_T
3076 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3077 	 *    received, the device server shall establish a unit
3078 	 *    attention condition for the initiator port associated with
3079 	 *    that I_T nexus, with the additional sense code set to
3080 	 *    RESERVATIONS RELEASED. If the type or scope have not
3081 	 *    changed, then no unit attention condition(s) shall be
3082 	 *    established for this reason.
3083 	 */
3084 	if ((prh_type != type) || (prh_scope != scope)) {
3085 		spin_lock(&pr_tmpl->registration_lock);
3086 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3087 				&pr_tmpl->registration_list, pr_reg_list) {
3088 
3089 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3090 			if (calling_it_nexus)
3091 				continue;
3092 
3093 			target_ua_allocate_lun(pr_reg->pr_reg_nacl,
3094 					pr_reg->pr_res_mapped_lun, 0x2A,
3095 					ASCQ_2AH_RESERVATIONS_RELEASED);
3096 		}
3097 		spin_unlock(&pr_tmpl->registration_lock);
3098 	}
3099 	spin_unlock(&dev->dev_reservation_lock);
3100 	/*
3101 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3102 	 * All received CDBs for the matching existing reservation and
3103 	 * registrations undergo ABORT_TASK logic.
3104 	 *
3105 	 * From there, core_scsi3_release_preempt_and_abort() will
3106 	 * release every registration in the list (which have already
3107 	 * been removed from the primary pr_reg list), except the
3108 	 * new persistent reservation holder, the calling Initiator Port.
3109 	 */
3110 	if (preempt_type == PREEMPT_AND_ABORT) {
3111 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3112 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3113 						pr_reg_n);
3114 	}
3115 
3116 	if (pr_tmpl->pr_aptpl_active)
3117 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3118 
3119 	core_scsi3_put_pr_reg(pr_reg_n);
3120 	core_scsi3_pr_generation(cmd->se_dev);
3121 	return 0;
3122 }
3123 
3124 static sense_reason_t
3125 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3126 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3127 {
3128 	switch (type) {
3129 	case PR_TYPE_WRITE_EXCLUSIVE:
3130 	case PR_TYPE_EXCLUSIVE_ACCESS:
3131 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3132 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3133 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3134 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3135 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3136 					      sa_res_key, preempt_type);
3137 	default:
3138 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3139 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3140 		return TCM_INVALID_CDB_FIELD;
3141 	}
3142 }
3143 
3144 
3145 static sense_reason_t
3146 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3147 		u64 sa_res_key, int aptpl, int unreg)
3148 {
3149 	struct se_session *se_sess = cmd->se_sess;
3150 	struct se_device *dev = cmd->se_dev;
3151 	struct se_dev_entry *dest_se_deve = NULL;
3152 	struct se_lun *se_lun = cmd->se_lun, *tmp_lun;
3153 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3154 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3155 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3156 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3157 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3158 	unsigned char *buf;
3159 	const unsigned char *initiator_str;
3160 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
3161 	u32 tid_len, tmp_tid_len;
3162 	int new_reg = 0, type, scope, matching_iname;
3163 	sense_reason_t ret;
3164 	unsigned short rtpi;
3165 	unsigned char proto_ident;
3166 
3167 	if (!se_sess || !se_lun) {
3168 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3169 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3170 	}
3171 
3172 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3173 	se_tpg = se_sess->se_tpg;
3174 	tf_ops = se_tpg->se_tpg_tfo;
3175 	/*
3176 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3177 	 *	Register behaviors for a REGISTER AND MOVE service action
3178 	 *
3179 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3180 	 */
3181 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3182 				se_sess);
3183 	if (!pr_reg) {
3184 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3185 			" *pr_reg for REGISTER_AND_MOVE\n");
3186 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3187 	}
3188 	/*
3189 	 * The provided reservation key much match the existing reservation key
3190 	 * provided during this initiator's I_T nexus registration.
3191 	 */
3192 	if (res_key != pr_reg->pr_res_key) {
3193 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3194 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3195 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3196 		ret = TCM_RESERVATION_CONFLICT;
3197 		goto out_put_pr_reg;
3198 	}
3199 	/*
3200 	 * The service active reservation key needs to be non zero
3201 	 */
3202 	if (!sa_res_key) {
3203 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3204 			" sa_res_key\n");
3205 		ret = TCM_INVALID_PARAMETER_LIST;
3206 		goto out_put_pr_reg;
3207 	}
3208 
3209 	/*
3210 	 * Determine the Relative Target Port Identifier where the reservation
3211 	 * will be moved to for the TransportID containing SCSI initiator WWN
3212 	 * information.
3213 	 */
3214 	buf = transport_kmap_data_sg(cmd);
3215 	if (!buf) {
3216 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3217 		goto out_put_pr_reg;
3218 	}
3219 
3220 	rtpi = get_unaligned_be16(&buf[18]);
3221 	tid_len = get_unaligned_be32(&buf[20]);
3222 	transport_kunmap_data_sg(cmd);
3223 	buf = NULL;
3224 
3225 	if ((tid_len + 24) != cmd->data_length) {
3226 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3227 			" does not equal CDB data_length: %u\n", tid_len,
3228 			cmd->data_length);
3229 		ret = TCM_INVALID_PARAMETER_LIST;
3230 		goto out_put_pr_reg;
3231 	}
3232 
3233 	spin_lock(&dev->se_port_lock);
3234 	list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
3235 		if (tmp_lun->lun_rtpi != rtpi)
3236 			continue;
3237 		dest_se_tpg = tmp_lun->lun_tpg;
3238 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3239 		if (!dest_tf_ops)
3240 			continue;
3241 
3242 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3243 		spin_unlock(&dev->se_port_lock);
3244 
3245 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3246 			pr_err("core_scsi3_tpg_depend_item() failed"
3247 				" for dest_se_tpg\n");
3248 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3249 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3250 			goto out_put_pr_reg;
3251 		}
3252 
3253 		spin_lock(&dev->se_port_lock);
3254 		break;
3255 	}
3256 	spin_unlock(&dev->se_port_lock);
3257 
3258 	if (!dest_se_tpg || !dest_tf_ops) {
3259 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3260 			" fabric ops from Relative Target Port Identifier:"
3261 			" %hu\n", rtpi);
3262 		ret = TCM_INVALID_PARAMETER_LIST;
3263 		goto out_put_pr_reg;
3264 	}
3265 
3266 	buf = transport_kmap_data_sg(cmd);
3267 	if (!buf) {
3268 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3269 		goto out_put_pr_reg;
3270 	}
3271 	proto_ident = (buf[24] & 0x0f);
3272 
3273 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3274 			" 0x%02x\n", proto_ident);
3275 
3276 	if (proto_ident != dest_se_tpg->proto_id) {
3277 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3278 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3279 			" from fabric: %s\n", proto_ident,
3280 			dest_se_tpg->proto_id,
3281 			dest_tf_ops->fabric_name);
3282 		ret = TCM_INVALID_PARAMETER_LIST;
3283 		goto out;
3284 	}
3285 	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
3286 			&buf[24], &tmp_tid_len, &iport_ptr);
3287 	if (!initiator_str) {
3288 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3289 			" initiator_str from Transport ID\n");
3290 		ret = TCM_INVALID_PARAMETER_LIST;
3291 		goto out;
3292 	}
3293 
3294 	transport_kunmap_data_sg(cmd);
3295 	buf = NULL;
3296 
3297 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3298 		" %s\n", dest_tf_ops->fabric_name, (iport_ptr != NULL) ?
3299 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3300 		iport_ptr : "");
3301 	/*
3302 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3303 	 * action specifies a TransportID that is the same as the initiator port
3304 	 * of the I_T nexus for the command received, then the command shall
3305 	 * be terminated with CHECK CONDITION status, with the sense key set to
3306 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3307 	 * IN PARAMETER LIST.
3308 	 */
3309 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3310 	matching_iname = (!strcmp(initiator_str,
3311 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3312 	if (!matching_iname)
3313 		goto after_iport_check;
3314 
3315 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3316 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3317 			" matches: %s on received I_T Nexus\n", initiator_str,
3318 			pr_reg_nacl->initiatorname);
3319 		ret = TCM_INVALID_PARAMETER_LIST;
3320 		goto out;
3321 	}
3322 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3323 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3324 			" matches: %s %s on received I_T Nexus\n",
3325 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3326 			pr_reg->pr_reg_isid);
3327 		ret = TCM_INVALID_PARAMETER_LIST;
3328 		goto out;
3329 	}
3330 after_iport_check:
3331 	/*
3332 	 * Locate the destination struct se_node_acl from the received Transport ID
3333 	 */
3334 	mutex_lock(&dest_se_tpg->acl_node_mutex);
3335 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3336 				initiator_str);
3337 	if (dest_node_acl)
3338 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3339 	mutex_unlock(&dest_se_tpg->acl_node_mutex);
3340 
3341 	if (!dest_node_acl) {
3342 		pr_err("Unable to locate %s dest_node_acl for"
3343 			" TransportID%s\n", dest_tf_ops->fabric_name,
3344 			initiator_str);
3345 		ret = TCM_INVALID_PARAMETER_LIST;
3346 		goto out;
3347 	}
3348 
3349 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3350 		pr_err("core_scsi3_nodeacl_depend_item() for"
3351 			" dest_node_acl\n");
3352 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3353 		dest_node_acl = NULL;
3354 		ret = TCM_INVALID_PARAMETER_LIST;
3355 		goto out;
3356 	}
3357 
3358 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3359 		" %s from TransportID\n", dest_tf_ops->fabric_name,
3360 		dest_node_acl->initiatorname);
3361 
3362 	/*
3363 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3364 	 * PORT IDENTIFIER.
3365 	 */
3366 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3367 	if (!dest_se_deve) {
3368 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3369 			" %hu\n",  dest_tf_ops->fabric_name, rtpi);
3370 		ret = TCM_INVALID_PARAMETER_LIST;
3371 		goto out;
3372 	}
3373 
3374 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3375 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3376 		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
3377 		dest_se_deve = NULL;
3378 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3379 		goto out;
3380 	}
3381 
3382 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3383 		" ACL for dest_se_deve->mapped_lun: %llu\n",
3384 		dest_tf_ops->fabric_name, dest_node_acl->initiatorname,
3385 		dest_se_deve->mapped_lun);
3386 
3387 	/*
3388 	 * A persistent reservation needs to already existing in order to
3389 	 * successfully complete the REGISTER_AND_MOVE service action..
3390 	 */
3391 	spin_lock(&dev->dev_reservation_lock);
3392 	pr_res_holder = dev->dev_pr_res_holder;
3393 	if (!pr_res_holder) {
3394 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3395 			" currently held\n");
3396 		spin_unlock(&dev->dev_reservation_lock);
3397 		ret = TCM_INVALID_CDB_FIELD;
3398 		goto out;
3399 	}
3400 	/*
3401 	 * The received on I_T Nexus must be the reservation holder.
3402 	 *
3403 	 * From spc4r17 section 5.7.8  Table 50 --
3404 	 * 	Register behaviors for a REGISTER AND MOVE service action
3405 	 */
3406 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3407 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3408 			" Nexus is not reservation holder\n");
3409 		spin_unlock(&dev->dev_reservation_lock);
3410 		ret = TCM_RESERVATION_CONFLICT;
3411 		goto out;
3412 	}
3413 	/*
3414 	 * From spc4r17 section 5.7.8: registering and moving reservation
3415 	 *
3416 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3417 	 * action is received and the established persistent reservation is a
3418 	 * Write Exclusive - All Registrants type or Exclusive Access -
3419 	 * All Registrants type reservation, then the command shall be completed
3420 	 * with RESERVATION CONFLICT status.
3421 	 */
3422 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3423 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3424 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3425 			" reservation for type: %s\n",
3426 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3427 		spin_unlock(&dev->dev_reservation_lock);
3428 		ret = TCM_RESERVATION_CONFLICT;
3429 		goto out;
3430 	}
3431 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3432 	/*
3433 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3434 	 */
3435 	type = pr_res_holder->pr_res_type;
3436 	scope = pr_res_holder->pr_res_type;
3437 	/*
3438 	 * c) Associate the reservation key specified in the SERVICE ACTION
3439 	 *    RESERVATION KEY field with the I_T nexus specified as the
3440 	 *    destination of the register and move, where:
3441 	 *    A) The I_T nexus is specified by the TransportID and the
3442 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3443 	 *    B) Regardless of the TransportID format used, the association for
3444 	 *       the initiator port is based on either the initiator port name
3445 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3446 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3447 	 *       transport protocols where port names are not required;
3448 	 * d) Register the reservation key specified in the SERVICE ACTION
3449 	 *    RESERVATION KEY field;
3450 	 * e) Retain the reservation key specified in the SERVICE ACTION
3451 	 *    RESERVATION KEY field and associated information;
3452 	 *
3453 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3454 	 * register an I_T nexus that is already registered with the same
3455 	 * reservation key or a different reservation key.
3456 	 */
3457 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3458 					iport_ptr);
3459 	if (!dest_pr_reg) {
3460 		struct se_lun *dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
3461 				kref_read(&dest_se_deve->pr_kref) != 0);
3462 
3463 		spin_unlock(&dev->dev_reservation_lock);
3464 		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
3465 					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
3466 					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
3467 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3468 			goto out;
3469 		}
3470 		spin_lock(&dev->dev_reservation_lock);
3471 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3472 						iport_ptr);
3473 		new_reg = 1;
3474 	}
3475 	/*
3476 	 * f) Release the persistent reservation for the persistent reservation
3477 	 *    holder (i.e., the I_T nexus on which the
3478 	 */
3479 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3480 					  dev->dev_pr_res_holder, 0, 0);
3481 	/*
3482 	 * g) Move the persistent reservation to the specified I_T nexus using
3483 	 *    the same scope and type as the persistent reservation released in
3484 	 *    item f); and
3485 	 */
3486 	dev->dev_pr_res_holder = dest_pr_reg;
3487 	dest_pr_reg->pr_res_holder = 1;
3488 	dest_pr_reg->pr_res_type = type;
3489 	pr_reg->pr_res_scope = scope;
3490 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3491 	/*
3492 	 * Increment PRGeneration for existing registrations..
3493 	 */
3494 	if (!new_reg)
3495 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3496 	spin_unlock(&dev->dev_reservation_lock);
3497 
3498 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3499 		" created new reservation holder TYPE: %s on object RTPI:"
3500 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->fabric_name,
3501 		core_scsi3_pr_dump_type(type), rtpi,
3502 		dest_pr_reg->pr_res_generation);
3503 	pr_debug("SPC-3 PR Successfully moved reservation from"
3504 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3505 		tf_ops->fabric_name, pr_reg_nacl->initiatorname,
3506 		i_buf, dest_tf_ops->fabric_name,
3507 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3508 		iport_ptr : "");
3509 	/*
3510 	 * It is now safe to release configfs group dependencies for destination
3511 	 * of Transport ID Initiator Device/Port Identifier
3512 	 */
3513 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3514 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3515 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3516 	/*
3517 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3518 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3519 	 */
3520 	if (unreg) {
3521 		spin_lock(&pr_tmpl->registration_lock);
3522 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3523 		spin_unlock(&pr_tmpl->registration_lock);
3524 	} else
3525 		core_scsi3_put_pr_reg(pr_reg);
3526 
3527 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3528 
3529 	core_scsi3_put_pr_reg(dest_pr_reg);
3530 	return 0;
3531 out:
3532 	if (buf)
3533 		transport_kunmap_data_sg(cmd);
3534 	if (dest_se_deve)
3535 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3536 	if (dest_node_acl)
3537 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3538 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3539 
3540 out_put_pr_reg:
3541 	core_scsi3_put_pr_reg(pr_reg);
3542 	return ret;
3543 }
3544 
3545 /*
3546  * See spc4r17 section 6.14 Table 170
3547  */
3548 sense_reason_t
3549 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3550 {
3551 	struct se_device *dev = cmd->se_dev;
3552 	unsigned char *cdb = &cmd->t_task_cdb[0];
3553 	unsigned char *buf;
3554 	u64 res_key, sa_res_key;
3555 	int sa, scope, type, aptpl;
3556 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3557 	sense_reason_t ret;
3558 
3559 	/*
3560 	 * Following spc2r20 5.5.1 Reservations overview:
3561 	 *
3562 	 * If a logical unit has been reserved by any RESERVE command and is
3563 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3564 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3565 	 * initiator or service action and shall terminate with a RESERVATION
3566 	 * CONFLICT status.
3567 	 */
3568 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3569 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3570 			" SPC-2 reservation is held, returning"
3571 			" RESERVATION_CONFLICT\n");
3572 		return TCM_RESERVATION_CONFLICT;
3573 	}
3574 
3575 	/*
3576 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3577 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3578 	 */
3579 	if (!cmd->se_sess)
3580 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3581 
3582 	if (cmd->data_length < 24) {
3583 		pr_warn("SPC-PR: Received PR OUT parameter list"
3584 			" length too small: %u\n", cmd->data_length);
3585 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3586 	}
3587 
3588 	/*
3589 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3590 	 */
3591 	sa = (cdb[1] & 0x1f);
3592 	scope = (cdb[2] & 0xf0);
3593 	type = (cdb[2] & 0x0f);
3594 
3595 	buf = transport_kmap_data_sg(cmd);
3596 	if (!buf)
3597 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3598 
3599 	/*
3600 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3601 	 */
3602 	res_key = get_unaligned_be64(&buf[0]);
3603 	sa_res_key = get_unaligned_be64(&buf[8]);
3604 	/*
3605 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3606 	 * SCSI TransportIDs.
3607 	 */
3608 	if (sa != PRO_REGISTER_AND_MOVE) {
3609 		spec_i_pt = (buf[20] & 0x08);
3610 		all_tg_pt = (buf[20] & 0x04);
3611 		aptpl = (buf[20] & 0x01);
3612 	} else {
3613 		aptpl = (buf[17] & 0x01);
3614 		unreg = (buf[17] & 0x02);
3615 	}
3616 	/*
3617 	 * If the backend device has been configured to force APTPL metadata
3618 	 * write-out, go ahead and propigate aptpl=1 down now.
3619 	 */
3620 	if (dev->dev_attrib.force_pr_aptpl)
3621 		aptpl = 1;
3622 
3623 	transport_kunmap_data_sg(cmd);
3624 	buf = NULL;
3625 
3626 	/*
3627 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3628 	 */
3629 	if (spec_i_pt && (sa != PRO_REGISTER))
3630 		return TCM_INVALID_PARAMETER_LIST;
3631 
3632 	/*
3633 	 * From spc4r17 section 6.14:
3634 	 *
3635 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3636 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3637 	 * the command shall be terminated with CHECK CONDITION status, with
3638 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3639 	 * code set to PARAMETER LIST LENGTH ERROR.
3640 	 */
3641 	if (!spec_i_pt && (sa != PRO_REGISTER_AND_MOVE) &&
3642 	    (cmd->data_length != 24)) {
3643 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3644 			" list length: %u\n", cmd->data_length);
3645 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3646 	}
3647 
3648 	/*
3649 	 * (core_scsi3_emulate_pro_* function parameters
3650 	 * are defined by spc4r17 Table 174:
3651 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3652 	 */
3653 	switch (sa) {
3654 	case PRO_REGISTER:
3655 		ret = core_scsi3_emulate_pro_register(cmd,
3656 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3657 		break;
3658 	case PRO_RESERVE:
3659 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3660 		break;
3661 	case PRO_RELEASE:
3662 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3663 		break;
3664 	case PRO_CLEAR:
3665 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3666 		break;
3667 	case PRO_PREEMPT:
3668 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3669 					res_key, sa_res_key, PREEMPT);
3670 		break;
3671 	case PRO_PREEMPT_AND_ABORT:
3672 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3673 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3674 		break;
3675 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3676 		ret = core_scsi3_emulate_pro_register(cmd,
3677 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3678 		break;
3679 	case PRO_REGISTER_AND_MOVE:
3680 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3681 				sa_res_key, aptpl, unreg);
3682 		break;
3683 	default:
3684 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3685 			" action: 0x%02x\n", sa);
3686 		return TCM_INVALID_CDB_FIELD;
3687 	}
3688 
3689 	if (!ret)
3690 		target_complete_cmd(cmd, GOOD);
3691 	return ret;
3692 }
3693 
3694 /*
3695  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3696  *
3697  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3698  */
3699 static sense_reason_t
3700 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3701 {
3702 	struct se_device *dev = cmd->se_dev;
3703 	struct t10_pr_registration *pr_reg;
3704 	unsigned char *buf;
3705 	u32 add_len = 0, off = 8;
3706 
3707 	if (cmd->data_length < 8) {
3708 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3709 			" too small\n", cmd->data_length);
3710 		return TCM_INVALID_CDB_FIELD;
3711 	}
3712 
3713 	buf = transport_kmap_data_sg(cmd);
3714 	if (!buf)
3715 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3716 
3717 	put_unaligned_be32(dev->t10_pr.pr_generation, buf);
3718 
3719 	spin_lock(&dev->t10_pr.registration_lock);
3720 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3721 			pr_reg_list) {
3722 		/*
3723 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3724 		 * next reservation key list descriptor.
3725 		 */
3726 		if (off + 8 <= cmd->data_length) {
3727 			put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3728 			off += 8;
3729 		}
3730 		/*
3731 		 * SPC5r17: 6.16.2 READ KEYS service action
3732 		 * The ADDITIONAL LENGTH field indicates the number of bytes in
3733 		 * the Reservation key list. The contents of the ADDITIONAL
3734 		 * LENGTH field are not altered based on the allocation length
3735 		 */
3736 		add_len += 8;
3737 	}
3738 	spin_unlock(&dev->t10_pr.registration_lock);
3739 
3740 	put_unaligned_be32(add_len, &buf[4]);
3741 
3742 	transport_kunmap_data_sg(cmd);
3743 
3744 	return 0;
3745 }
3746 
3747 /*
3748  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3749  *
3750  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3751  */
3752 static sense_reason_t
3753 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3754 {
3755 	struct se_device *dev = cmd->se_dev;
3756 	struct t10_pr_registration *pr_reg;
3757 	unsigned char *buf;
3758 	u64 pr_res_key;
3759 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3760 
3761 	if (cmd->data_length < 8) {
3762 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3763 			" too small\n", cmd->data_length);
3764 		return TCM_INVALID_CDB_FIELD;
3765 	}
3766 
3767 	buf = transport_kmap_data_sg(cmd);
3768 	if (!buf)
3769 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3770 
3771 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3772 
3773 	spin_lock(&dev->dev_reservation_lock);
3774 	pr_reg = dev->dev_pr_res_holder;
3775 	if (pr_reg) {
3776 		/*
3777 		 * Set the hardcoded Additional Length
3778 		 */
3779 		put_unaligned_be32(add_len, &buf[4]);
3780 
3781 		if (cmd->data_length < 22)
3782 			goto err;
3783 
3784 		/*
3785 		 * Set the Reservation key.
3786 		 *
3787 		 * From spc4r17, section 5.7.10:
3788 		 * A persistent reservation holder has its reservation key
3789 		 * returned in the parameter data from a PERSISTENT
3790 		 * RESERVE IN command with READ RESERVATION service action as
3791 		 * follows:
3792 		 * a) For a persistent reservation of the type Write Exclusive
3793 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3794 		 *      the reservation key shall be set to zero; or
3795 		 * b) For all other persistent reservation types, the
3796 		 *    reservation key shall be set to the registered
3797 		 *    reservation key for the I_T nexus that holds the
3798 		 *    persistent reservation.
3799 		 */
3800 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3801 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3802 			pr_res_key = 0;
3803 		else
3804 			pr_res_key = pr_reg->pr_res_key;
3805 
3806 		put_unaligned_be64(pr_res_key, &buf[8]);
3807 		/*
3808 		 * Set the SCOPE and TYPE
3809 		 */
3810 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3811 			  (pr_reg->pr_res_type & 0x0f);
3812 	}
3813 
3814 err:
3815 	spin_unlock(&dev->dev_reservation_lock);
3816 	transport_kunmap_data_sg(cmd);
3817 
3818 	return 0;
3819 }
3820 
3821 /*
3822  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3823  *
3824  * See spc4r17 section 6.13.4 Table 165
3825  */
3826 static sense_reason_t
3827 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3828 {
3829 	struct se_device *dev = cmd->se_dev;
3830 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3831 	unsigned char *buf;
3832 	u16 add_len = 8; /* Hardcoded to 8. */
3833 
3834 	if (cmd->data_length < 6) {
3835 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3836 			" %u too small\n", cmd->data_length);
3837 		return TCM_INVALID_CDB_FIELD;
3838 	}
3839 
3840 	buf = transport_kmap_data_sg(cmd);
3841 	if (!buf)
3842 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3843 
3844 	put_unaligned_be16(add_len, &buf[0]);
3845 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3846 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3847 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3848 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3849 	/*
3850 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3851 	 * set the TMV: Task Mask Valid bit.
3852 	 */
3853 	buf[3] |= 0x80;
3854 	/*
3855 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3856 	 */
3857 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3858 	/*
3859 	 * PTPL_A: Persistence across Target Power Loss Active bit
3860 	 */
3861 	if (pr_tmpl->pr_aptpl_active)
3862 		buf[3] |= 0x01;
3863 	/*
3864 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3865 	 */
3866 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3867 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3868 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3869 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3870 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3871 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3872 
3873 	transport_kunmap_data_sg(cmd);
3874 
3875 	return 0;
3876 }
3877 
3878 /*
3879  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3880  *
3881  * See spc4r17 section 6.13.5 Table 168 and 169
3882  */
3883 static sense_reason_t
3884 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3885 {
3886 	struct se_device *dev = cmd->se_dev;
3887 	struct se_node_acl *se_nacl;
3888 	struct se_portal_group *se_tpg;
3889 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3890 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3891 	unsigned char *buf;
3892 	u32 add_desc_len = 0, add_len = 0;
3893 	u32 off = 8; /* off into first Full Status descriptor */
3894 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3895 	int exp_desc_len, desc_len;
3896 	bool all_reg = false;
3897 
3898 	if (cmd->data_length < 8) {
3899 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3900 			" too small\n", cmd->data_length);
3901 		return TCM_INVALID_CDB_FIELD;
3902 	}
3903 
3904 	buf = transport_kmap_data_sg(cmd);
3905 	if (!buf)
3906 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3907 
3908 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3909 
3910 	spin_lock(&dev->dev_reservation_lock);
3911 	if (dev->dev_pr_res_holder) {
3912 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3913 
3914 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3915 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3916 			all_reg = true;
3917 			pr_res_type = pr_holder->pr_res_type;
3918 			pr_res_scope = pr_holder->pr_res_scope;
3919 		}
3920 	}
3921 	spin_unlock(&dev->dev_reservation_lock);
3922 
3923 	spin_lock(&pr_tmpl->registration_lock);
3924 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3925 			&pr_tmpl->registration_list, pr_reg_list) {
3926 
3927 		se_nacl = pr_reg->pr_reg_nacl;
3928 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3929 		add_desc_len = 0;
3930 
3931 		atomic_inc_mb(&pr_reg->pr_res_holders);
3932 		spin_unlock(&pr_tmpl->registration_lock);
3933 		/*
3934 		 * Determine expected length of $FABRIC_MOD specific
3935 		 * TransportID full status descriptor..
3936 		 */
3937 		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
3938 					&format_code);
3939 		if (exp_desc_len < 0 ||
3940 		    exp_desc_len + add_len > cmd->data_length) {
3941 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3942 				" out of buffer: %d\n", cmd->data_length);
3943 			spin_lock(&pr_tmpl->registration_lock);
3944 			atomic_dec_mb(&pr_reg->pr_res_holders);
3945 			break;
3946 		}
3947 		/*
3948 		 * Set RESERVATION KEY
3949 		 */
3950 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3951 		off += 8;
3952 		off += 4; /* Skip Over Reserved area */
3953 
3954 		/*
3955 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3956 		 */
3957 		if (pr_reg->pr_reg_all_tg_pt)
3958 			buf[off] = 0x02;
3959 		/*
3960 		 * The struct se_lun pointer will be present for the
3961 		 * reservation holder for PR_HOLDER bit.
3962 		 *
3963 		 * Also, if this registration is the reservation
3964 		 * holder or there is an All Registrants reservation
3965 		 * active, fill in SCOPE and TYPE in the next byte.
3966 		 */
3967 		if (pr_reg->pr_res_holder) {
3968 			buf[off++] |= 0x01;
3969 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3970 				     (pr_reg->pr_res_type & 0x0f);
3971 		} else if (all_reg) {
3972 			buf[off++] |= 0x01;
3973 			buf[off++] = (pr_res_scope & 0xf0) |
3974 				     (pr_res_type & 0x0f);
3975 		} else {
3976 			off += 2;
3977 		}
3978 
3979 		off += 4; /* Skip over reserved area */
3980 		/*
3981 		 * From spc4r17 6.3.15:
3982 		 *
3983 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
3984 		 * IDENTIFIER field contains the relative port identifier (see
3985 		 * 3.1.120) of the target port that is part of the I_T nexus
3986 		 * described by this full status descriptor. If the ALL_TG_PT
3987 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
3988 		 * IDENTIFIER field are not defined by this standard.
3989 		 */
3990 		if (!pr_reg->pr_reg_all_tg_pt) {
3991 			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;
3992 
3993 			put_unaligned_be16(sep_rtpi, &buf[off]);
3994 			off += 2;
3995 		} else
3996 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
3997 
3998 		buf[off+4] = se_tpg->proto_id;
3999 
4000 		/*
4001 		 * Now, have the $FABRIC_MOD fill in the transport ID.
4002 		 */
4003 		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
4004 				&format_code, &buf[off+4]);
4005 
4006 		spin_lock(&pr_tmpl->registration_lock);
4007 		atomic_dec_mb(&pr_reg->pr_res_holders);
4008 
4009 		if (desc_len < 0)
4010 			break;
4011 		/*
4012 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4013 		 */
4014 		put_unaligned_be32(desc_len, &buf[off]);
4015 		off += 4;
4016 		/*
4017 		 * Size of full desctipor header minus TransportID
4018 		 * containing $FABRIC_MOD specific) initiator device/port
4019 		 * WWN information.
4020 		 *
4021 		 *  See spc4r17 Section 6.13.5 Table 169
4022 		 */
4023 		add_desc_len = (24 + desc_len);
4024 
4025 		off += desc_len;
4026 		add_len += add_desc_len;
4027 	}
4028 	spin_unlock(&pr_tmpl->registration_lock);
4029 	/*
4030 	 * Set ADDITIONAL_LENGTH
4031 	 */
4032 	put_unaligned_be32(add_len, &buf[4]);
4033 
4034 	transport_kunmap_data_sg(cmd);
4035 
4036 	return 0;
4037 }
4038 
4039 sense_reason_t
4040 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4041 {
4042 	sense_reason_t ret;
4043 
4044 	/*
4045 	 * Following spc2r20 5.5.1 Reservations overview:
4046 	 *
4047 	 * If a logical unit has been reserved by any RESERVE command and is
4048 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4049 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4050 	 * initiator or service action and shall terminate with a RESERVATION
4051 	 * CONFLICT status.
4052 	 */
4053 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4054 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4055 			" SPC-2 reservation is held, returning"
4056 			" RESERVATION_CONFLICT\n");
4057 		return TCM_RESERVATION_CONFLICT;
4058 	}
4059 
4060 	switch (cmd->t_task_cdb[1] & 0x1f) {
4061 	case PRI_READ_KEYS:
4062 		ret = core_scsi3_pri_read_keys(cmd);
4063 		break;
4064 	case PRI_READ_RESERVATION:
4065 		ret = core_scsi3_pri_read_reservation(cmd);
4066 		break;
4067 	case PRI_REPORT_CAPABILITIES:
4068 		ret = core_scsi3_pri_report_capabilities(cmd);
4069 		break;
4070 	case PRI_READ_FULL_STATUS:
4071 		ret = core_scsi3_pri_read_full_status(cmd);
4072 		break;
4073 	default:
4074 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4075 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4076 		return TCM_INVALID_CDB_FIELD;
4077 	}
4078 
4079 	if (!ret)
4080 		target_complete_cmd(cmd, GOOD);
4081 	return ret;
4082 }
4083 
4084 sense_reason_t
4085 target_check_reservation(struct se_cmd *cmd)
4086 {
4087 	struct se_device *dev = cmd->se_dev;
4088 	sense_reason_t ret;
4089 
4090 	if (!cmd->se_sess)
4091 		return 0;
4092 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4093 		return 0;
4094 	if (!dev->dev_attrib.emulate_pr)
4095 		return 0;
4096 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
4097 		return 0;
4098 
4099 	spin_lock(&dev->dev_reservation_lock);
4100 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4101 		ret = target_scsi2_reservation_check(cmd);
4102 	else
4103 		ret = target_scsi3_pr_reservation_check(cmd);
4104 	spin_unlock(&dev->dev_reservation_lock);
4105 
4106 	return ret;
4107 }
4108