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 		/* fall through */
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 		/* fall through */
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 	struct se_portal_group *tpg;
1163 
1164 	spin_lock(&pr_tmpl->registration_lock);
1165 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1166 			&pr_tmpl->registration_list, pr_reg_list) {
1167 		/*
1168 		 * First look for a matching struct se_node_acl
1169 		 */
1170 		if (pr_reg->pr_reg_nacl != nacl)
1171 			continue;
1172 
1173 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1174 		/*
1175 		 * If this registration does NOT contain a fabric provided
1176 		 * ISID, then we have found a match.
1177 		 */
1178 		if (!pr_reg->isid_present_at_reg) {
1179 			/*
1180 			 * Determine if this SCSI device server requires that
1181 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1182 			 * for fabric modules (iSCSI) requiring them.
1183 			 */
1184 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1185 				if (dev->dev_attrib.enforce_pr_isids)
1186 					continue;
1187 			}
1188 			atomic_inc_mb(&pr_reg->pr_res_holders);
1189 			spin_unlock(&pr_tmpl->registration_lock);
1190 			return pr_reg;
1191 		}
1192 		/*
1193 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1194 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1195 		 * matching ISID to be provided by the local SCSI Initiator Port.
1196 		 */
1197 		if (!isid)
1198 			continue;
1199 		if (strcmp(isid, pr_reg->pr_reg_isid))
1200 			continue;
1201 
1202 		atomic_inc_mb(&pr_reg->pr_res_holders);
1203 		spin_unlock(&pr_tmpl->registration_lock);
1204 		return pr_reg;
1205 	}
1206 	spin_unlock(&pr_tmpl->registration_lock);
1207 
1208 	return NULL;
1209 }
1210 
1211 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1212 	struct se_device *dev,
1213 	struct se_node_acl *nacl,
1214 	struct se_session *sess)
1215 {
1216 	struct se_portal_group *tpg = nacl->se_tpg;
1217 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1218 
1219 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1220 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1221 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1222 					PR_REG_ISID_LEN);
1223 		isid_ptr = &buf[0];
1224 	}
1225 
1226 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1227 }
1228 
1229 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1230 {
1231 	atomic_dec_mb(&pr_reg->pr_res_holders);
1232 }
1233 
1234 static int core_scsi3_check_implicit_release(
1235 	struct se_device *dev,
1236 	struct t10_pr_registration *pr_reg)
1237 {
1238 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1239 	struct t10_pr_registration *pr_res_holder;
1240 	int ret = 0;
1241 
1242 	spin_lock(&dev->dev_reservation_lock);
1243 	pr_res_holder = dev->dev_pr_res_holder;
1244 	if (!pr_res_holder) {
1245 		spin_unlock(&dev->dev_reservation_lock);
1246 		return ret;
1247 	}
1248 	if (pr_res_holder == pr_reg) {
1249 		/*
1250 		 * Perform an implicit RELEASE if the registration that
1251 		 * is being released is holding the reservation.
1252 		 *
1253 		 * From spc4r17, section 5.7.11.1:
1254 		 *
1255 		 * e) If the I_T nexus is the persistent reservation holder
1256 		 *    and the persistent reservation is not an all registrants
1257 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1258 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1259 		 *    service action with the SERVICE ACTION RESERVATION KEY
1260 		 *    field set to zero (see 5.7.11.3).
1261 		 */
1262 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1263 		ret = 1;
1264 		/*
1265 		 * For 'All Registrants' reservation types, all existing
1266 		 * registrations are still processed as reservation holders
1267 		 * in core_scsi3_pr_seq_non_holder() after the initial
1268 		 * reservation holder is implicitly released here.
1269 		 */
1270 	} else if (pr_reg->pr_reg_all_tg_pt &&
1271 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1272 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1273 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1274 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1275 			" UNREGISTER while existing reservation with matching"
1276 			" key 0x%016Lx is present from another SCSI Initiator"
1277 			" Port\n", pr_reg->pr_res_key);
1278 		ret = -EPERM;
1279 	}
1280 	spin_unlock(&dev->dev_reservation_lock);
1281 
1282 	return ret;
1283 }
1284 
1285 static void __core_scsi3_free_registration(
1286 	struct se_device *dev,
1287 	struct t10_pr_registration *pr_reg,
1288 	struct list_head *preempt_and_abort_list,
1289 	int dec_holders)
1290 	__releases(&pr_tmpl->registration_lock)
1291 	__acquires(&pr_tmpl->registration_lock)
1292 {
1293 	const struct target_core_fabric_ops *tfo =
1294 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1295 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1296 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1297 	struct se_dev_entry *deve;
1298 	char i_buf[PR_REG_ISID_ID_LEN];
1299 
1300 	lockdep_assert_held(&pr_tmpl->registration_lock);
1301 
1302 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1303 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1304 
1305 	if (!list_empty(&pr_reg->pr_reg_list))
1306 		list_del(&pr_reg->pr_reg_list);
1307 	/*
1308 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1309 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1310 	 */
1311 	if (dec_holders)
1312 		core_scsi3_put_pr_reg(pr_reg);
1313 
1314 	spin_unlock(&pr_tmpl->registration_lock);
1315 	/*
1316 	 * Wait until all reference from any other I_T nexuses for this
1317 	 * *pr_reg have been released.  Because list_del() is called above,
1318 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1319 	 * count back to zero, and we release *pr_reg.
1320 	 */
1321 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1322 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1323 				tfo->fabric_name);
1324 		cpu_relax();
1325 	}
1326 
1327 	rcu_read_lock();
1328 	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
1329 	if (deve)
1330 		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1331 	rcu_read_unlock();
1332 
1333 	spin_lock(&pr_tmpl->registration_lock);
1334 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1335 		" Node: %s%s\n", tfo->fabric_name,
1336 		pr_reg->pr_reg_nacl->initiatorname,
1337 		i_buf);
1338 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1339 		" Port(s)\n", tfo->fabric_name,
1340 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1341 		dev->transport->name);
1342 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1343 		" 0x%08x\n", tfo->fabric_name, pr_reg->pr_res_key,
1344 		pr_reg->pr_res_generation);
1345 
1346 	if (!preempt_and_abort_list) {
1347 		pr_reg->pr_reg_deve = NULL;
1348 		pr_reg->pr_reg_nacl = NULL;
1349 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1350 		return;
1351 	}
1352 	/*
1353 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1354 	 * are released once the ABORT_TASK_SET has completed..
1355 	 */
1356 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1357 }
1358 
1359 void core_scsi3_free_pr_reg_from_nacl(
1360 	struct se_device *dev,
1361 	struct se_node_acl *nacl)
1362 {
1363 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1364 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1365 	bool free_reg = false;
1366 	/*
1367 	 * If the passed se_node_acl matches the reservation holder,
1368 	 * release the reservation.
1369 	 */
1370 	spin_lock(&dev->dev_reservation_lock);
1371 	pr_res_holder = dev->dev_pr_res_holder;
1372 	if ((pr_res_holder != NULL) &&
1373 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1374 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1375 		free_reg = true;
1376 	}
1377 	spin_unlock(&dev->dev_reservation_lock);
1378 	/*
1379 	 * Release any registration associated with the struct se_node_acl.
1380 	 */
1381 	spin_lock(&pr_tmpl->registration_lock);
1382 	if (pr_res_holder && free_reg)
1383 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1384 
1385 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1386 			&pr_tmpl->registration_list, pr_reg_list) {
1387 
1388 		if (pr_reg->pr_reg_nacl != nacl)
1389 			continue;
1390 
1391 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1392 	}
1393 	spin_unlock(&pr_tmpl->registration_lock);
1394 }
1395 
1396 void core_scsi3_free_all_registrations(
1397 	struct se_device *dev)
1398 {
1399 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1400 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1401 
1402 	spin_lock(&dev->dev_reservation_lock);
1403 	pr_res_holder = dev->dev_pr_res_holder;
1404 	if (pr_res_holder != NULL) {
1405 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1406 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1407 						  pr_res_holder, 0, 0);
1408 	}
1409 	spin_unlock(&dev->dev_reservation_lock);
1410 
1411 	spin_lock(&pr_tmpl->registration_lock);
1412 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1413 			&pr_tmpl->registration_list, pr_reg_list) {
1414 
1415 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1416 	}
1417 	spin_unlock(&pr_tmpl->registration_lock);
1418 
1419 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1420 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1421 				pr_reg_aptpl_list) {
1422 		list_del(&pr_reg->pr_reg_aptpl_list);
1423 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1424 	}
1425 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1426 }
1427 
1428 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1429 {
1430 	return target_depend_item(&tpg->tpg_group.cg_item);
1431 }
1432 
1433 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1434 {
1435 	target_undepend_item(&tpg->tpg_group.cg_item);
1436 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1437 }
1438 
1439 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1440 {
1441 	if (nacl->dynamic_node_acl)
1442 		return 0;
1443 	return target_depend_item(&nacl->acl_group.cg_item);
1444 }
1445 
1446 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1447 {
1448 	if (!nacl->dynamic_node_acl)
1449 		target_undepend_item(&nacl->acl_group.cg_item);
1450 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1451 }
1452 
1453 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1454 {
1455 	struct se_lun_acl *lun_acl;
1456 
1457 	/*
1458 	 * For nacl->dynamic_node_acl=1
1459 	 */
1460 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1461 				kref_read(&se_deve->pr_kref) != 0);
1462 	if (!lun_acl)
1463 		return 0;
1464 
1465 	return target_depend_item(&lun_acl->se_lun_group.cg_item);
1466 }
1467 
1468 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1469 {
1470 	struct se_lun_acl *lun_acl;
1471 
1472 	/*
1473 	 * For nacl->dynamic_node_acl=1
1474 	 */
1475 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1476 				kref_read(&se_deve->pr_kref) != 0);
1477 	if (!lun_acl) {
1478 		kref_put(&se_deve->pr_kref, target_pr_kref_release);
1479 		return;
1480 	}
1481 
1482 	target_undepend_item(&lun_acl->se_lun_group.cg_item);
1483 	kref_put(&se_deve->pr_kref, target_pr_kref_release);
1484 }
1485 
1486 static sense_reason_t
1487 core_scsi3_decode_spec_i_port(
1488 	struct se_cmd *cmd,
1489 	struct se_portal_group *tpg,
1490 	unsigned char *l_isid,
1491 	u64 sa_res_key,
1492 	int all_tg_pt,
1493 	int aptpl)
1494 {
1495 	struct se_device *dev = cmd->se_dev;
1496 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1497 	struct se_session *se_sess = cmd->se_sess;
1498 	struct se_node_acl *dest_node_acl = NULL;
1499 	struct se_dev_entry *dest_se_deve = NULL;
1500 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1501 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1502 	LIST_HEAD(tid_dest_list);
1503 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1504 	unsigned char *buf, *ptr, proto_ident;
1505 	const unsigned char *i_str = NULL;
1506 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1507 	sense_reason_t ret;
1508 	u32 tpdl, tid_len = 0;
1509 	u32 dest_rtpi = 0;
1510 
1511 	/*
1512 	 * Allocate a struct pr_transport_id_holder and setup the
1513 	 * local_node_acl pointer and add to struct list_head tid_dest_list
1514 	 * for add registration processing in the loop of tid_dest_list below.
1515 	 */
1516 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1517 	if (!tidh_new) {
1518 		pr_err("Unable to allocate tidh_new\n");
1519 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1520 	}
1521 	INIT_LIST_HEAD(&tidh_new->dest_list);
1522 	tidh_new->dest_tpg = tpg;
1523 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1524 
1525 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1526 				se_sess->se_node_acl, cmd->se_lun,
1527 				NULL, cmd->orig_fe_lun, l_isid,
1528 				sa_res_key, all_tg_pt, aptpl);
1529 	if (!local_pr_reg) {
1530 		kfree(tidh_new);
1531 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1532 	}
1533 	tidh_new->dest_pr_reg = local_pr_reg;
1534 	/*
1535 	 * The local I_T nexus does not hold any configfs dependances,
1536 	 * so we set tidh_new->dest_se_deve to NULL to prevent the
1537 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1538 	 */
1539 	tidh_new->dest_se_deve = NULL;
1540 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1541 
1542 	if (cmd->data_length < 28) {
1543 		pr_warn("SPC-PR: Received PR OUT parameter list"
1544 			" length too small: %u\n", cmd->data_length);
1545 		ret = TCM_INVALID_PARAMETER_LIST;
1546 		goto out;
1547 	}
1548 
1549 	buf = transport_kmap_data_sg(cmd);
1550 	if (!buf) {
1551 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1552 		goto out;
1553 	}
1554 
1555 	/*
1556 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1557 	 * first extract TransportID Parameter Data Length, and make sure
1558 	 * the value matches up to the SCSI expected data transfer length.
1559 	 */
1560 	tpdl = get_unaligned_be32(&buf[24]);
1561 
1562 	if ((tpdl + 28) != cmd->data_length) {
1563 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1564 			" does not equal CDB data_length: %u\n", tpdl,
1565 			cmd->data_length);
1566 		ret = TCM_INVALID_PARAMETER_LIST;
1567 		goto out_unmap;
1568 	}
1569 	/*
1570 	 * Start processing the received transport IDs using the
1571 	 * receiving I_T Nexus portal's fabric dependent methods to
1572 	 * obtain the SCSI Initiator Port/Device Identifiers.
1573 	 */
1574 	ptr = &buf[28];
1575 
1576 	while (tpdl > 0) {
1577 		struct se_lun *dest_lun, *tmp_lun;
1578 
1579 		proto_ident = (ptr[0] & 0x0f);
1580 		dest_tpg = NULL;
1581 
1582 		spin_lock(&dev->se_port_lock);
1583 		list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
1584 			tmp_tpg = tmp_lun->lun_tpg;
1585 
1586 			/*
1587 			 * Look for the matching proto_ident provided by
1588 			 * the received TransportID
1589 			 */
1590 			if (tmp_tpg->proto_id != proto_ident)
1591 				continue;
1592 			dest_rtpi = tmp_lun->lun_rtpi;
1593 
1594 			i_str = target_parse_pr_out_transport_id(tmp_tpg,
1595 					ptr, &tid_len, &iport_ptr);
1596 			if (!i_str)
1597 				continue;
1598 
1599 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1600 			spin_unlock(&dev->se_port_lock);
1601 
1602 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1603 				pr_err(" core_scsi3_tpg_depend_item()"
1604 					" for tmp_tpg\n");
1605 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1606 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1607 				goto out_unmap;
1608 			}
1609 			/*
1610 			 * Locate the destination initiator ACL to be registered
1611 			 * from the decoded fabric module specific TransportID
1612 			 * at *i_str.
1613 			 */
1614 			mutex_lock(&tmp_tpg->acl_node_mutex);
1615 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1616 						tmp_tpg, i_str);
1617 			if (dest_node_acl)
1618 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1619 			mutex_unlock(&tmp_tpg->acl_node_mutex);
1620 
1621 			if (!dest_node_acl) {
1622 				core_scsi3_tpg_undepend_item(tmp_tpg);
1623 				spin_lock(&dev->se_port_lock);
1624 				continue;
1625 			}
1626 
1627 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1628 				pr_err("configfs_depend_item() failed"
1629 					" for dest_node_acl->acl_group\n");
1630 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1631 				core_scsi3_tpg_undepend_item(tmp_tpg);
1632 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1633 				goto out_unmap;
1634 			}
1635 
1636 			dest_tpg = tmp_tpg;
1637 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1638 				" %s Port RTPI: %hu\n",
1639 				dest_tpg->se_tpg_tfo->fabric_name,
1640 				dest_node_acl->initiatorname, dest_rtpi);
1641 
1642 			spin_lock(&dev->se_port_lock);
1643 			break;
1644 		}
1645 		spin_unlock(&dev->se_port_lock);
1646 
1647 		if (!dest_tpg) {
1648 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1649 					" dest_tpg\n");
1650 			ret = TCM_INVALID_PARAMETER_LIST;
1651 			goto out_unmap;
1652 		}
1653 
1654 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1655 			" tid_len: %d for %s + %s\n",
1656 			dest_tpg->se_tpg_tfo->fabric_name, cmd->data_length,
1657 			tpdl, tid_len, i_str, iport_ptr);
1658 
1659 		if (tid_len > tpdl) {
1660 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1661 				" %u for Transport ID: %s\n", tid_len, ptr);
1662 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1663 			core_scsi3_tpg_undepend_item(dest_tpg);
1664 			ret = TCM_INVALID_PARAMETER_LIST;
1665 			goto out_unmap;
1666 		}
1667 		/*
1668 		 * Locate the desintation struct se_dev_entry pointer for matching
1669 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1670 		 * Target Port.
1671 		 */
1672 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1673 					dest_rtpi);
1674 		if (!dest_se_deve) {
1675 			pr_err("Unable to locate %s dest_se_deve"
1676 				" from destination RTPI: %hu\n",
1677 				dest_tpg->se_tpg_tfo->fabric_name,
1678 				dest_rtpi);
1679 
1680 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1681 			core_scsi3_tpg_undepend_item(dest_tpg);
1682 			ret = TCM_INVALID_PARAMETER_LIST;
1683 			goto out_unmap;
1684 		}
1685 
1686 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1687 			pr_err("core_scsi3_lunacl_depend_item()"
1688 					" failed\n");
1689 			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
1690 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1691 			core_scsi3_tpg_undepend_item(dest_tpg);
1692 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1693 			goto out_unmap;
1694 		}
1695 
1696 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1697 			" dest_se_deve mapped_lun: %llu\n",
1698 			dest_tpg->se_tpg_tfo->fabric_name,
1699 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1700 
1701 		/*
1702 		 * Skip any TransportIDs that already have a registration for
1703 		 * this target port.
1704 		 */
1705 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1706 					iport_ptr);
1707 		if (pr_reg_e) {
1708 			core_scsi3_put_pr_reg(pr_reg_e);
1709 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1710 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1711 			core_scsi3_tpg_undepend_item(dest_tpg);
1712 			ptr += tid_len;
1713 			tpdl -= tid_len;
1714 			tid_len = 0;
1715 			continue;
1716 		}
1717 		/*
1718 		 * Allocate a struct pr_transport_id_holder and setup
1719 		 * the dest_node_acl and dest_se_deve pointers for the
1720 		 * loop below.
1721 		 */
1722 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1723 				GFP_KERNEL);
1724 		if (!tidh_new) {
1725 			pr_err("Unable to allocate tidh_new\n");
1726 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1727 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1728 			core_scsi3_tpg_undepend_item(dest_tpg);
1729 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1730 			goto out_unmap;
1731 		}
1732 		INIT_LIST_HEAD(&tidh_new->dest_list);
1733 		tidh_new->dest_tpg = dest_tpg;
1734 		tidh_new->dest_node_acl = dest_node_acl;
1735 		tidh_new->dest_se_deve = dest_se_deve;
1736 
1737 		/*
1738 		 * Allocate, but do NOT add the registration for the
1739 		 * TransportID referenced SCSI Initiator port.  This
1740 		 * done because of the following from spc4r17 in section
1741 		 * 6.14.3 wrt SPEC_I_PT:
1742 		 *
1743 		 * "If a registration fails for any initiator port (e.g., if th
1744 		 * logical unit does not have enough resources available to
1745 		 * hold the registration information), no registrations shall be
1746 		 * made, and the command shall be terminated with
1747 		 * CHECK CONDITION status."
1748 		 *
1749 		 * That means we call __core_scsi3_alloc_registration() here,
1750 		 * and then call __core_scsi3_add_registration() in the
1751 		 * 2nd loop which will never fail.
1752 		 */
1753 		dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
1754 				kref_read(&dest_se_deve->pr_kref) != 0);
1755 
1756 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1757 					dest_node_acl, dest_lun, dest_se_deve,
1758 					dest_se_deve->mapped_lun, iport_ptr,
1759 					sa_res_key, all_tg_pt, aptpl);
1760 		if (!dest_pr_reg) {
1761 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1762 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1763 			core_scsi3_tpg_undepend_item(dest_tpg);
1764 			kfree(tidh_new);
1765 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1766 			goto out_unmap;
1767 		}
1768 		tidh_new->dest_pr_reg = dest_pr_reg;
1769 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1770 
1771 		ptr += tid_len;
1772 		tpdl -= tid_len;
1773 		tid_len = 0;
1774 
1775 	}
1776 
1777 	transport_kunmap_data_sg(cmd);
1778 
1779 	/*
1780 	 * Go ahead and create a registrations from tid_dest_list for the
1781 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1782 	 * and dest_se_deve.
1783 	 *
1784 	 * The SA Reservation Key from the PROUT is set for the
1785 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1786 	 * means that the TransportID Initiator port will be
1787 	 * registered on all of the target ports in the SCSI target device
1788 	 * ALL_TG_PT=0 means the registration will only be for the
1789 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1790 	 * was received.
1791 	 */
1792 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1793 		dest_tpg = tidh->dest_tpg;
1794 		dest_node_acl = tidh->dest_node_acl;
1795 		dest_se_deve = tidh->dest_se_deve;
1796 		dest_pr_reg = tidh->dest_pr_reg;
1797 
1798 		list_del(&tidh->dest_list);
1799 		kfree(tidh);
1800 
1801 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1802 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1803 
1804 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1805 					dest_pr_reg, 0, 0);
1806 
1807 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1808 			" registered Transport ID for Node: %s%s Mapped LUN:"
1809 			" %llu\n", dest_tpg->se_tpg_tfo->fabric_name,
1810 			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
1811 			dest_se_deve->mapped_lun : 0);
1812 
1813 		if (!dest_se_deve) {
1814 			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1815 				 target_pr_kref_release);
1816 			continue;
1817 		}
1818 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1819 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1820 		core_scsi3_tpg_undepend_item(dest_tpg);
1821 	}
1822 
1823 	return 0;
1824 out_unmap:
1825 	transport_kunmap_data_sg(cmd);
1826 out:
1827 	/*
1828 	 * For the failure case, release everything from tid_dest_list
1829 	 * including *dest_pr_reg and the configfs dependances..
1830 	 */
1831 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1832 		dest_tpg = tidh->dest_tpg;
1833 		dest_node_acl = tidh->dest_node_acl;
1834 		dest_se_deve = tidh->dest_se_deve;
1835 		dest_pr_reg = tidh->dest_pr_reg;
1836 
1837 		list_del(&tidh->dest_list);
1838 		kfree(tidh);
1839 		/*
1840 		 * Release any extra ALL_TG_PT=1 registrations for
1841 		 * the SPEC_I_PT=1 case.
1842 		 */
1843 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1844 				&dest_pr_reg->pr_reg_atp_list,
1845 				pr_reg_atp_mem_list) {
1846 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1847 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1848 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1849 		}
1850 
1851 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1852 
1853 		if (!dest_se_deve) {
1854 			kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1855 				 target_pr_kref_release);
1856 			continue;
1857 		}
1858 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1859 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1860 		core_scsi3_tpg_undepend_item(dest_tpg);
1861 	}
1862 	return ret;
1863 }
1864 
1865 static int core_scsi3_update_aptpl_buf(
1866 	struct se_device *dev,
1867 	unsigned char *buf,
1868 	u32 pr_aptpl_buf_len)
1869 {
1870 	struct se_portal_group *tpg;
1871 	struct t10_pr_registration *pr_reg;
1872 	unsigned char tmp[512], isid_buf[32];
1873 	ssize_t len = 0;
1874 	int reg_count = 0;
1875 	int ret = 0;
1876 
1877 	spin_lock(&dev->dev_reservation_lock);
1878 	spin_lock(&dev->t10_pr.registration_lock);
1879 	/*
1880 	 * Walk the registration list..
1881 	 */
1882 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1883 			pr_reg_list) {
1884 
1885 		tmp[0] = '\0';
1886 		isid_buf[0] = '\0';
1887 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1888 		/*
1889 		 * Write out any ISID value to APTPL metadata that was included
1890 		 * in the original registration.
1891 		 */
1892 		if (pr_reg->isid_present_at_reg)
1893 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1894 					pr_reg->pr_reg_isid);
1895 		/*
1896 		 * Include special metadata if the pr_reg matches the
1897 		 * reservation holder.
1898 		 */
1899 		if (dev->dev_pr_res_holder == pr_reg) {
1900 			snprintf(tmp, 512, "PR_REG_START: %d"
1901 				"\ninitiator_fabric=%s\n"
1902 				"initiator_node=%s\n%s"
1903 				"sa_res_key=%llu\n"
1904 				"res_holder=1\nres_type=%02x\n"
1905 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1906 				"mapped_lun=%llu\n", reg_count,
1907 				tpg->se_tpg_tfo->fabric_name,
1908 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1909 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1910 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1911 				pr_reg->pr_res_mapped_lun);
1912 		} else {
1913 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1914 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1915 				"sa_res_key=%llu\nres_holder=0\n"
1916 				"res_all_tg_pt=%d\nmapped_lun=%llu\n",
1917 				reg_count, tpg->se_tpg_tfo->fabric_name,
1918 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1919 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1920 				pr_reg->pr_res_mapped_lun);
1921 		}
1922 
1923 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1924 			pr_err("Unable to update renaming APTPL metadata,"
1925 			       " reallocating larger buffer\n");
1926 			ret = -EMSGSIZE;
1927 			goto out;
1928 		}
1929 		len += sprintf(buf+len, "%s", tmp);
1930 
1931 		/*
1932 		 * Include information about the associated SCSI target port.
1933 		 */
1934 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1935 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%llu\nPR_REG_END:"
1936 			" %d\n", tpg->se_tpg_tfo->fabric_name,
1937 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1938 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1939 			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
1940 			reg_count);
1941 
1942 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1943 			pr_err("Unable to update renaming APTPL metadata,"
1944 			       " reallocating larger buffer\n");
1945 			ret = -EMSGSIZE;
1946 			goto out;
1947 		}
1948 		len += sprintf(buf+len, "%s", tmp);
1949 		reg_count++;
1950 	}
1951 
1952 	if (!reg_count)
1953 		len += sprintf(buf+len, "No Registrations or Reservations");
1954 
1955 out:
1956 	spin_unlock(&dev->t10_pr.registration_lock);
1957 	spin_unlock(&dev->dev_reservation_lock);
1958 
1959 	return ret;
1960 }
1961 
1962 static int __core_scsi3_write_aptpl_to_file(
1963 	struct se_device *dev,
1964 	unsigned char *buf)
1965 {
1966 	struct t10_wwn *wwn = &dev->t10_wwn;
1967 	struct file *file;
1968 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1969 	char *path;
1970 	u32 pr_aptpl_buf_len;
1971 	int ret;
1972 	loff_t pos = 0;
1973 
1974 	path = kasprintf(GFP_KERNEL, "%s/pr/aptpl_%s", db_root,
1975 			&wwn->unit_serial[0]);
1976 	if (!path)
1977 		return -ENOMEM;
1978 
1979 	file = filp_open(path, flags, 0600);
1980 	if (IS_ERR(file)) {
1981 		pr_err("filp_open(%s) for APTPL metadata"
1982 			" failed\n", path);
1983 		kfree(path);
1984 		return PTR_ERR(file);
1985 	}
1986 
1987 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1988 
1989 	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);
1990 
1991 	if (ret < 0)
1992 		pr_debug("Error writing APTPL metadata file: %s\n", path);
1993 	fput(file);
1994 	kfree(path);
1995 
1996 	return (ret < 0) ? -EIO : 0;
1997 }
1998 
1999 /*
2000  * Clear the APTPL metadata if APTPL has been disabled, otherwise
2001  * write out the updated metadata to struct file for this SCSI device.
2002  */
2003 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
2004 {
2005 	unsigned char *buf;
2006 	int rc, len = PR_APTPL_BUF_LEN;
2007 
2008 	if (!aptpl) {
2009 		char *null_buf = "No Registrations or Reservations\n";
2010 
2011 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
2012 		dev->t10_pr.pr_aptpl_active = 0;
2013 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
2014 
2015 		if (rc)
2016 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2017 
2018 		return 0;
2019 	}
2020 retry:
2021 	buf = vzalloc(len);
2022 	if (!buf)
2023 		return TCM_OUT_OF_RESOURCES;
2024 
2025 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
2026 	if (rc < 0) {
2027 		vfree(buf);
2028 		len *= 2;
2029 		goto retry;
2030 	}
2031 
2032 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2033 	if (rc != 0) {
2034 		pr_err("SPC-3 PR: Could not update APTPL\n");
2035 		vfree(buf);
2036 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2037 	}
2038 	dev->t10_pr.pr_aptpl_active = 1;
2039 	vfree(buf);
2040 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2041 	return 0;
2042 }
2043 
2044 static sense_reason_t
2045 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2046 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2047 {
2048 	struct se_session *se_sess = cmd->se_sess;
2049 	struct se_device *dev = cmd->se_dev;
2050 	struct se_lun *se_lun = cmd->se_lun;
2051 	struct se_portal_group *se_tpg;
2052 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2053 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2054 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2055 	sense_reason_t ret = TCM_NO_SENSE;
2056 	int pr_holder = 0, type;
2057 
2058 	if (!se_sess || !se_lun) {
2059 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2060 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2061 	}
2062 	se_tpg = se_sess->se_tpg;
2063 
2064 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2065 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2066 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2067 				PR_REG_ISID_LEN);
2068 		isid_ptr = &isid_buf[0];
2069 	}
2070 	/*
2071 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2072 	 */
2073 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2074 	if (!pr_reg) {
2075 		if (res_key) {
2076 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2077 				" for SA REGISTER, returning CONFLICT\n");
2078 			return TCM_RESERVATION_CONFLICT;
2079 		}
2080 		/*
2081 		 * Do nothing but return GOOD status.
2082 		 */
2083 		if (!sa_res_key)
2084 			return 0;
2085 
2086 		if (!spec_i_pt) {
2087 			/*
2088 			 * Perform the Service Action REGISTER on the Initiator
2089 			 * Port Endpoint that the PRO was received from on the
2090 			 * Logical Unit of the SCSI device server.
2091 			 */
2092 			if (core_scsi3_alloc_registration(cmd->se_dev,
2093 					se_sess->se_node_acl, cmd->se_lun,
2094 					NULL, cmd->orig_fe_lun, isid_ptr,
2095 					sa_res_key, all_tg_pt, aptpl,
2096 					register_type, 0)) {
2097 				pr_err("Unable to allocate"
2098 					" struct t10_pr_registration\n");
2099 				return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
2100 			}
2101 		} else {
2102 			/*
2103 			 * Register both the Initiator port that received
2104 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2105 			 * TransportID from Parameter list and loop through
2106 			 * fabric dependent parameter list while calling
2107 			 * logic from of core_scsi3_alloc_registration() for
2108 			 * each TransportID provided SCSI Initiator Port/Device
2109 			 */
2110 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2111 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2112 			if (ret != 0)
2113 				return ret;
2114 		}
2115 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2116 	}
2117 
2118 	/* ok, existing registration */
2119 
2120 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2121 		pr_err("SPC-3 PR REGISTER: Received"
2122 		       " res_key: 0x%016Lx does not match"
2123 		       " existing SA REGISTER res_key:"
2124 		       " 0x%016Lx\n", res_key,
2125 		       pr_reg->pr_res_key);
2126 		ret = TCM_RESERVATION_CONFLICT;
2127 		goto out;
2128 	}
2129 
2130 	if (spec_i_pt) {
2131 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2132 			" set on a registered nexus\n");
2133 		ret = TCM_INVALID_PARAMETER_LIST;
2134 		goto out;
2135 	}
2136 
2137 	/*
2138 	 * An existing ALL_TG_PT=1 registration being released
2139 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2140 	 */
2141 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2142 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2143 			" registration exists, but ALL_TG_PT=1 bit not"
2144 			" present in received PROUT\n");
2145 		ret = TCM_INVALID_CDB_FIELD;
2146 		goto out;
2147 	}
2148 
2149 	/*
2150 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2151 	 */
2152 	if (sa_res_key) {
2153 		/*
2154 		 * Increment PRgeneration counter for struct se_device"
2155 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2156 		 * READ_KEYS service action.
2157 		 */
2158 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2159 		pr_reg->pr_res_key = sa_res_key;
2160 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2161 			 " Key for %s to: 0x%016Lx PRgeneration:"
2162 			 " 0x%08x\n", cmd->se_tfo->fabric_name,
2163 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2164 			 pr_reg->pr_reg_nacl->initiatorname,
2165 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2166 
2167 	} else {
2168 		/*
2169 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2170 		 */
2171 		type = pr_reg->pr_res_type;
2172 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2173 							      pr_reg);
2174 		if (pr_holder < 0) {
2175 			ret = TCM_RESERVATION_CONFLICT;
2176 			goto out;
2177 		}
2178 
2179 		spin_lock(&pr_tmpl->registration_lock);
2180 		/*
2181 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2182 		 * and matching pr_res_key.
2183 		 */
2184 		if (pr_reg->pr_reg_all_tg_pt) {
2185 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2186 					&pr_tmpl->registration_list,
2187 					pr_reg_list) {
2188 
2189 				if (!pr_reg_p->pr_reg_all_tg_pt)
2190 					continue;
2191 				if (pr_reg_p->pr_res_key != res_key)
2192 					continue;
2193 				if (pr_reg == pr_reg_p)
2194 					continue;
2195 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2196 					   pr_reg_p->pr_reg_nacl->initiatorname))
2197 					continue;
2198 
2199 				__core_scsi3_free_registration(dev,
2200 						pr_reg_p, NULL, 0);
2201 			}
2202 		}
2203 
2204 		/*
2205 		 * Release the calling I_T Nexus registration now..
2206 		 */
2207 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2208 		pr_reg = NULL;
2209 
2210 		/*
2211 		 * From spc4r17, section 5.7.11.3 Unregistering
2212 		 *
2213 		 * If the persistent reservation is a registrants only
2214 		 * type, the device server shall establish a unit
2215 		 * attention condition for the initiator port associated
2216 		 * with every registered I_T nexus except for the I_T
2217 		 * nexus on which the PERSISTENT RESERVE OUT command was
2218 		 * received, with the additional sense code set to
2219 		 * RESERVATIONS RELEASED.
2220 		 */
2221 		if (pr_holder &&
2222 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2223 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2224 			list_for_each_entry(pr_reg_p,
2225 					&pr_tmpl->registration_list,
2226 					pr_reg_list) {
2227 
2228 				target_ua_allocate_lun(
2229 					pr_reg_p->pr_reg_nacl,
2230 					pr_reg_p->pr_res_mapped_lun,
2231 					0x2A,
2232 					ASCQ_2AH_RESERVATIONS_RELEASED);
2233 			}
2234 		}
2235 
2236 		spin_unlock(&pr_tmpl->registration_lock);
2237 	}
2238 
2239 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2240 
2241 out:
2242 	if (pr_reg)
2243 		core_scsi3_put_pr_reg(pr_reg);
2244 	return ret;
2245 }
2246 
2247 unsigned char *core_scsi3_pr_dump_type(int type)
2248 {
2249 	switch (type) {
2250 	case PR_TYPE_WRITE_EXCLUSIVE:
2251 		return "Write Exclusive Access";
2252 	case PR_TYPE_EXCLUSIVE_ACCESS:
2253 		return "Exclusive Access";
2254 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2255 		return "Write Exclusive Access, Registrants Only";
2256 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2257 		return "Exclusive Access, Registrants Only";
2258 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2259 		return "Write Exclusive Access, All Registrants";
2260 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2261 		return "Exclusive Access, All Registrants";
2262 	default:
2263 		break;
2264 	}
2265 
2266 	return "Unknown SPC-3 PR Type";
2267 }
2268 
2269 static sense_reason_t
2270 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2271 {
2272 	struct se_device *dev = cmd->se_dev;
2273 	struct se_session *se_sess = cmd->se_sess;
2274 	struct se_lun *se_lun = cmd->se_lun;
2275 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2276 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2277 	char i_buf[PR_REG_ISID_ID_LEN];
2278 	sense_reason_t ret;
2279 
2280 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2281 
2282 	if (!se_sess || !se_lun) {
2283 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2284 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2285 	}
2286 	/*
2287 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2288 	 */
2289 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2290 				se_sess);
2291 	if (!pr_reg) {
2292 		pr_err("SPC-3 PR: Unable to locate"
2293 			" PR_REGISTERED *pr_reg for RESERVE\n");
2294 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2295 	}
2296 	/*
2297 	 * From spc4r17 Section 5.7.9: Reserving:
2298 	 *
2299 	 * An application client creates a persistent reservation by issuing
2300 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2301 	 * a registered I_T nexus with the following parameters:
2302 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2303 	 * 	 registered with the logical unit for the I_T nexus; and
2304 	 */
2305 	if (res_key != pr_reg->pr_res_key) {
2306 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2307 			" does not match existing SA REGISTER res_key:"
2308 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2309 		ret = TCM_RESERVATION_CONFLICT;
2310 		goto out_put_pr_reg;
2311 	}
2312 	/*
2313 	 * From spc4r17 Section 5.7.9: Reserving:
2314 	 *
2315 	 * From above:
2316 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2317 	 *     being created.
2318 	 *
2319 	 * Only one persistent reservation is allowed at a time per logical unit
2320 	 * and that persistent reservation has a scope of LU_SCOPE.
2321 	 */
2322 	if (scope != PR_SCOPE_LU_SCOPE) {
2323 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2324 		ret = TCM_INVALID_PARAMETER_LIST;
2325 		goto out_put_pr_reg;
2326 	}
2327 	/*
2328 	 * See if we have an existing PR reservation holder pointer at
2329 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2330 	 * *pr_res_holder.
2331 	 */
2332 	spin_lock(&dev->dev_reservation_lock);
2333 	pr_res_holder = dev->dev_pr_res_holder;
2334 	if (pr_res_holder) {
2335 		/*
2336 		 * From spc4r17 Section 5.7.9: Reserving:
2337 		 *
2338 		 * If the device server receives a PERSISTENT RESERVE OUT
2339 		 * command from an I_T nexus other than a persistent reservation
2340 		 * holder (see 5.7.10) that attempts to create a persistent
2341 		 * reservation when a persistent reservation already exists for
2342 		 * the logical unit, then the command shall be completed with
2343 		 * RESERVATION CONFLICT status.
2344 		 */
2345 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2346 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2347 			pr_err("SPC-3 PR: Attempted RESERVE from"
2348 				" [%s]: %s while reservation already held by"
2349 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2350 				cmd->se_tfo->fabric_name,
2351 				se_sess->se_node_acl->initiatorname,
2352 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2353 				pr_res_holder->pr_reg_nacl->initiatorname);
2354 
2355 			spin_unlock(&dev->dev_reservation_lock);
2356 			ret = TCM_RESERVATION_CONFLICT;
2357 			goto out_put_pr_reg;
2358 		}
2359 		/*
2360 		 * From spc4r17 Section 5.7.9: Reserving:
2361 		 *
2362 		 * If a persistent reservation holder attempts to modify the
2363 		 * type or scope of an existing persistent reservation, the
2364 		 * command shall be completed with RESERVATION CONFLICT status.
2365 		 */
2366 		if ((pr_res_holder->pr_res_type != type) ||
2367 		    (pr_res_holder->pr_res_scope != scope)) {
2368 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2369 			pr_err("SPC-3 PR: Attempted RESERVE from"
2370 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2371 				" while reservation already held by [%s]: %s,"
2372 				" returning RESERVATION_CONFLICT\n",
2373 				cmd->se_tfo->fabric_name,
2374 				se_sess->se_node_acl->initiatorname,
2375 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2376 				pr_res_holder->pr_reg_nacl->initiatorname);
2377 
2378 			spin_unlock(&dev->dev_reservation_lock);
2379 			ret = TCM_RESERVATION_CONFLICT;
2380 			goto out_put_pr_reg;
2381 		}
2382 		/*
2383 		 * From spc4r17 Section 5.7.9: Reserving:
2384 		 *
2385 		 * If the device server receives a PERSISTENT RESERVE OUT
2386 		 * command with RESERVE service action where the TYPE field and
2387 		 * the SCOPE field contain the same values as the existing type
2388 		 * and scope from a persistent reservation holder, it shall not
2389 		 * make any change to the existing persistent reservation and
2390 		 * shall completethe command with GOOD status.
2391 		 */
2392 		spin_unlock(&dev->dev_reservation_lock);
2393 		ret = 0;
2394 		goto out_put_pr_reg;
2395 	}
2396 	/*
2397 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2398 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2399 	 */
2400 	pr_reg->pr_res_scope = scope;
2401 	pr_reg->pr_res_type = type;
2402 	pr_reg->pr_res_holder = 1;
2403 	dev->dev_pr_res_holder = pr_reg;
2404 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2405 
2406 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2407 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2408 		cmd->se_tfo->fabric_name, core_scsi3_pr_dump_type(type),
2409 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2410 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2411 			cmd->se_tfo->fabric_name,
2412 			se_sess->se_node_acl->initiatorname,
2413 			i_buf);
2414 	spin_unlock(&dev->dev_reservation_lock);
2415 
2416 	if (pr_tmpl->pr_aptpl_active)
2417 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2418 
2419 	ret = 0;
2420 out_put_pr_reg:
2421 	core_scsi3_put_pr_reg(pr_reg);
2422 	return ret;
2423 }
2424 
2425 static sense_reason_t
2426 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2427 		u64 res_key)
2428 {
2429 	switch (type) {
2430 	case PR_TYPE_WRITE_EXCLUSIVE:
2431 	case PR_TYPE_EXCLUSIVE_ACCESS:
2432 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2433 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2434 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2435 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2436 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2437 	default:
2438 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2439 			" 0x%02x\n", type);
2440 		return TCM_INVALID_CDB_FIELD;
2441 	}
2442 }
2443 
2444 static void __core_scsi3_complete_pro_release(
2445 	struct se_device *dev,
2446 	struct se_node_acl *se_nacl,
2447 	struct t10_pr_registration *pr_reg,
2448 	int explicit,
2449 	int unreg)
2450 {
2451 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2452 	char i_buf[PR_REG_ISID_ID_LEN];
2453 	int pr_res_type = 0, pr_res_scope = 0;
2454 
2455 	lockdep_assert_held(&dev->dev_reservation_lock);
2456 
2457 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2458 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2459 	/*
2460 	 * Go ahead and release the current PR reservation holder.
2461 	 * If an All Registrants reservation is currently active and
2462 	 * a unregister operation is requested, replace the current
2463 	 * dev_pr_res_holder with another active registration.
2464 	 */
2465 	if (dev->dev_pr_res_holder) {
2466 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2467 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2468 		dev->dev_pr_res_holder->pr_res_type = 0;
2469 		dev->dev_pr_res_holder->pr_res_scope = 0;
2470 		dev->dev_pr_res_holder->pr_res_holder = 0;
2471 		dev->dev_pr_res_holder = NULL;
2472 	}
2473 	if (!unreg)
2474 		goto out;
2475 
2476 	spin_lock(&dev->t10_pr.registration_lock);
2477 	list_del_init(&pr_reg->pr_reg_list);
2478 	/*
2479 	 * If the I_T nexus is a reservation holder, the persistent reservation
2480 	 * is of an all registrants type, and the I_T nexus is the last remaining
2481 	 * registered I_T nexus, then the device server shall also release the
2482 	 * persistent reservation.
2483 	 */
2484 	if (!list_empty(&dev->t10_pr.registration_list) &&
2485 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2486 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2487 		dev->dev_pr_res_holder =
2488 			list_entry(dev->t10_pr.registration_list.next,
2489 				   struct t10_pr_registration, pr_reg_list);
2490 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2491 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2492 		dev->dev_pr_res_holder->pr_res_holder = 1;
2493 	}
2494 	spin_unlock(&dev->t10_pr.registration_lock);
2495 out:
2496 	if (!dev->dev_pr_res_holder) {
2497 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2498 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2499 			tfo->fabric_name, (explicit) ? "explicit" :
2500 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2501 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2502 	}
2503 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2504 		tfo->fabric_name, se_nacl->initiatorname,
2505 		i_buf);
2506 	/*
2507 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2508 	 */
2509 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2510 }
2511 
2512 static sense_reason_t
2513 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2514 		u64 res_key)
2515 {
2516 	struct se_device *dev = cmd->se_dev;
2517 	struct se_session *se_sess = cmd->se_sess;
2518 	struct se_lun *se_lun = cmd->se_lun;
2519 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2520 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2521 	sense_reason_t ret = 0;
2522 
2523 	if (!se_sess || !se_lun) {
2524 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2525 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2526 	}
2527 	/*
2528 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2529 	 */
2530 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2531 	if (!pr_reg) {
2532 		pr_err("SPC-3 PR: Unable to locate"
2533 			" PR_REGISTERED *pr_reg for RELEASE\n");
2534 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2535 	}
2536 	/*
2537 	 * From spc4r17 Section 5.7.11.2 Releasing:
2538 	 *
2539 	 * If there is no persistent reservation or in response to a persistent
2540 	 * reservation release request from a registered I_T nexus that is not a
2541 	 * persistent reservation holder (see 5.7.10), the device server shall
2542 	 * do the following:
2543 	 *
2544 	 *     a) Not release the persistent reservation, if any;
2545 	 *     b) Not remove any registrations; and
2546 	 *     c) Complete the command with GOOD status.
2547 	 */
2548 	spin_lock(&dev->dev_reservation_lock);
2549 	pr_res_holder = dev->dev_pr_res_holder;
2550 	if (!pr_res_holder) {
2551 		/*
2552 		 * No persistent reservation, return GOOD status.
2553 		 */
2554 		spin_unlock(&dev->dev_reservation_lock);
2555 		goto out_put_pr_reg;
2556 	}
2557 
2558 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2559 		/*
2560 		 * Release request from a registered I_T nexus that is not a
2561 		 * persistent reservation holder. return GOOD status.
2562 		 */
2563 		spin_unlock(&dev->dev_reservation_lock);
2564 		goto out_put_pr_reg;
2565 	}
2566 
2567 	/*
2568 	 * From spc4r17 Section 5.7.11.2 Releasing:
2569 	 *
2570 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2571 	 * release a persistent reservation.
2572 	 *
2573 	 * An application client releases the persistent reservation by issuing
2574 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2575 	 * an I_T nexus that is a persistent reservation holder with the
2576 	 * following parameters:
2577 	 *
2578 	 *     a) RESERVATION KEY field set to the value of the reservation key
2579 	 *	  that is registered with the logical unit for the I_T nexus;
2580 	 */
2581 	if (res_key != pr_reg->pr_res_key) {
2582 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2583 			" does not match existing SA REGISTER res_key:"
2584 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2585 		spin_unlock(&dev->dev_reservation_lock);
2586 		ret = TCM_RESERVATION_CONFLICT;
2587 		goto out_put_pr_reg;
2588 	}
2589 	/*
2590 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2591 	 *
2592 	 * b) TYPE field and SCOPE field set to match the persistent
2593 	 *    reservation being released.
2594 	 */
2595 	if ((pr_res_holder->pr_res_type != type) ||
2596 	    (pr_res_holder->pr_res_scope != scope)) {
2597 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2598 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2599 			" reservation from [%s]: %s with different TYPE "
2600 			"and/or SCOPE  while reservation already held by"
2601 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2602 			cmd->se_tfo->fabric_name,
2603 			se_sess->se_node_acl->initiatorname,
2604 			pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2605 			pr_res_holder->pr_reg_nacl->initiatorname);
2606 
2607 		spin_unlock(&dev->dev_reservation_lock);
2608 		ret = TCM_RESERVATION_CONFLICT;
2609 		goto out_put_pr_reg;
2610 	}
2611 	/*
2612 	 * In response to a persistent reservation release request from the
2613 	 * persistent reservation holder the device server shall perform a
2614 	 * release by doing the following as an uninterrupted series of actions:
2615 	 * a) Release the persistent reservation;
2616 	 * b) Not remove any registration(s);
2617 	 * c) If the released persistent reservation is a registrants only type
2618 	 * or all registrants type persistent reservation,
2619 	 *    the device server shall establish a unit attention condition for
2620 	 *    the initiator port associated with every regis-
2621 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2622 	 *    RESERVE OUT command with RELEASE service action was received,
2623 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2624 	 * d) If the persistent reservation is of any other type, the device
2625 	 *    server shall not establish a unit attention condition.
2626 	 */
2627 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2628 					  pr_reg, 1, 0);
2629 
2630 	spin_unlock(&dev->dev_reservation_lock);
2631 
2632 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2633 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2634 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2635 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2636 		/*
2637 		 * If no UNIT ATTENTION conditions will be established for
2638 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2639 		 * go ahead and check for APTPL=1 update+write below
2640 		 */
2641 		goto write_aptpl;
2642 	}
2643 
2644 	spin_lock(&pr_tmpl->registration_lock);
2645 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2646 			pr_reg_list) {
2647 		/*
2648 		 * Do not establish a UNIT ATTENTION condition
2649 		 * for the calling I_T Nexus
2650 		 */
2651 		if (pr_reg_p == pr_reg)
2652 			continue;
2653 
2654 		target_ua_allocate_lun(pr_reg_p->pr_reg_nacl,
2655 				pr_reg_p->pr_res_mapped_lun,
2656 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2657 	}
2658 	spin_unlock(&pr_tmpl->registration_lock);
2659 
2660 write_aptpl:
2661 	if (pr_tmpl->pr_aptpl_active)
2662 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2663 
2664 out_put_pr_reg:
2665 	core_scsi3_put_pr_reg(pr_reg);
2666 	return ret;
2667 }
2668 
2669 static sense_reason_t
2670 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2671 {
2672 	struct se_device *dev = cmd->se_dev;
2673 	struct se_node_acl *pr_reg_nacl;
2674 	struct se_session *se_sess = cmd->se_sess;
2675 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2676 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2677 	u64 pr_res_mapped_lun = 0;
2678 	int calling_it_nexus = 0;
2679 	/*
2680 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2681 	 */
2682 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2683 			se_sess->se_node_acl, se_sess);
2684 	if (!pr_reg_n) {
2685 		pr_err("SPC-3 PR: Unable to locate"
2686 			" PR_REGISTERED *pr_reg for CLEAR\n");
2687 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2688 	}
2689 	/*
2690 	 * From spc4r17 section 5.7.11.6, Clearing:
2691 	 *
2692 	 * Any application client may release the persistent reservation and
2693 	 * remove all registrations from a device server by issuing a
2694 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2695 	 * registered I_T nexus with the following parameter:
2696 	 *
2697 	 *	a) RESERVATION KEY field set to the value of the reservation key
2698 	 * 	   that is registered with the logical unit for the I_T nexus.
2699 	 */
2700 	if (res_key != pr_reg_n->pr_res_key) {
2701 		pr_err("SPC-3 PR REGISTER: Received"
2702 			" res_key: 0x%016Lx does not match"
2703 			" existing SA REGISTER res_key:"
2704 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2705 		core_scsi3_put_pr_reg(pr_reg_n);
2706 		return TCM_RESERVATION_CONFLICT;
2707 	}
2708 	/*
2709 	 * a) Release the persistent reservation, if any;
2710 	 */
2711 	spin_lock(&dev->dev_reservation_lock);
2712 	pr_res_holder = dev->dev_pr_res_holder;
2713 	if (pr_res_holder) {
2714 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2715 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2716 						  pr_res_holder, 0, 0);
2717 	}
2718 	spin_unlock(&dev->dev_reservation_lock);
2719 	/*
2720 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2721 	 */
2722 	spin_lock(&pr_tmpl->registration_lock);
2723 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2724 			&pr_tmpl->registration_list, pr_reg_list) {
2725 
2726 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2727 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2728 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2729 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2730 					calling_it_nexus);
2731 		/*
2732 		 * e) Establish a unit attention condition for the initiator
2733 		 *    port associated with every registered I_T nexus other
2734 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2735 		 *    command with CLEAR service action was received, with the
2736 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2737 		 */
2738 		if (!calling_it_nexus)
2739 			target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun,
2740 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2741 	}
2742 	spin_unlock(&pr_tmpl->registration_lock);
2743 
2744 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2745 		cmd->se_tfo->fabric_name);
2746 
2747 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2748 
2749 	core_scsi3_pr_generation(dev);
2750 	return 0;
2751 }
2752 
2753 static void __core_scsi3_complete_pro_preempt(
2754 	struct se_device *dev,
2755 	struct t10_pr_registration *pr_reg,
2756 	struct list_head *preempt_and_abort_list,
2757 	int type,
2758 	int scope,
2759 	enum preempt_type preempt_type)
2760 {
2761 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2762 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2763 	char i_buf[PR_REG_ISID_ID_LEN];
2764 
2765 	lockdep_assert_held(&dev->dev_reservation_lock);
2766 
2767 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2768 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2769 	/*
2770 	 * Do an implicit RELEASE of the existing reservation.
2771 	 */
2772 	if (dev->dev_pr_res_holder)
2773 		__core_scsi3_complete_pro_release(dev, nacl,
2774 						  dev->dev_pr_res_holder, 0, 0);
2775 
2776 	dev->dev_pr_res_holder = pr_reg;
2777 	pr_reg->pr_res_holder = 1;
2778 	pr_reg->pr_res_type = type;
2779 	pr_reg->pr_res_scope = scope;
2780 
2781 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2782 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2783 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2784 		core_scsi3_pr_dump_type(type),
2785 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2786 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2787 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2788 		nacl->initiatorname, i_buf);
2789 	/*
2790 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2791 	 * struct t10_pr_registration to the list that will be compared
2792 	 * against received CDBs..
2793 	 */
2794 	if (preempt_and_abort_list)
2795 		list_add_tail(&pr_reg->pr_reg_abort_list,
2796 				preempt_and_abort_list);
2797 }
2798 
2799 static void core_scsi3_release_preempt_and_abort(
2800 	struct list_head *preempt_and_abort_list,
2801 	struct t10_pr_registration *pr_reg_holder)
2802 {
2803 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2804 
2805 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2806 				pr_reg_abort_list) {
2807 
2808 		list_del(&pr_reg->pr_reg_abort_list);
2809 		if (pr_reg_holder == pr_reg)
2810 			continue;
2811 		if (pr_reg->pr_res_holder) {
2812 			pr_warn("pr_reg->pr_res_holder still set\n");
2813 			continue;
2814 		}
2815 
2816 		pr_reg->pr_reg_deve = NULL;
2817 		pr_reg->pr_reg_nacl = NULL;
2818 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2819 	}
2820 }
2821 
2822 static sense_reason_t
2823 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2824 		u64 sa_res_key, enum preempt_type preempt_type)
2825 {
2826 	struct se_device *dev = cmd->se_dev;
2827 	struct se_node_acl *pr_reg_nacl;
2828 	struct se_session *se_sess = cmd->se_sess;
2829 	LIST_HEAD(preempt_and_abort_list);
2830 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2831 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2832 	u64 pr_res_mapped_lun = 0;
2833 	int all_reg = 0, calling_it_nexus = 0;
2834 	bool sa_res_key_unmatched = sa_res_key != 0;
2835 	int prh_type = 0, prh_scope = 0;
2836 
2837 	if (!se_sess)
2838 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2839 
2840 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2841 				se_sess);
2842 	if (!pr_reg_n) {
2843 		pr_err("SPC-3 PR: Unable to locate"
2844 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2845 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2846 		return TCM_RESERVATION_CONFLICT;
2847 	}
2848 	if (pr_reg_n->pr_res_key != res_key) {
2849 		core_scsi3_put_pr_reg(pr_reg_n);
2850 		return TCM_RESERVATION_CONFLICT;
2851 	}
2852 	if (scope != PR_SCOPE_LU_SCOPE) {
2853 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2854 		core_scsi3_put_pr_reg(pr_reg_n);
2855 		return TCM_INVALID_PARAMETER_LIST;
2856 	}
2857 
2858 	spin_lock(&dev->dev_reservation_lock);
2859 	pr_res_holder = dev->dev_pr_res_holder;
2860 	if (pr_res_holder &&
2861 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2862 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2863 		all_reg = 1;
2864 
2865 	if (!all_reg && !sa_res_key) {
2866 		spin_unlock(&dev->dev_reservation_lock);
2867 		core_scsi3_put_pr_reg(pr_reg_n);
2868 		return TCM_INVALID_PARAMETER_LIST;
2869 	}
2870 	/*
2871 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2872 	 *
2873 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2874 	 * persistent reservation holder or there is no persistent reservation
2875 	 * holder (i.e., there is no persistent reservation), then the device
2876 	 * server shall perform a preempt by doing the following in an
2877 	 * uninterrupted series of actions. (See below..)
2878 	 */
2879 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2880 		/*
2881 		 * No existing or SA Reservation Key matching reservations..
2882 		 *
2883 		 * PROUT SA PREEMPT with All Registrant type reservations are
2884 		 * allowed to be processed without a matching SA Reservation Key
2885 		 */
2886 		spin_lock(&pr_tmpl->registration_lock);
2887 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2888 				&pr_tmpl->registration_list, pr_reg_list) {
2889 			/*
2890 			 * Removing of registrations in non all registrants
2891 			 * type reservations without a matching SA reservation
2892 			 * key.
2893 			 *
2894 			 * a) Remove the registrations for all I_T nexuses
2895 			 *    specified by the SERVICE ACTION RESERVATION KEY
2896 			 *    field;
2897 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2898 			 * c) Process tasks as defined in 5.7.1; and
2899 			 * d) Establish a unit attention condition for the
2900 			 *    initiator port associated with every I_T nexus
2901 			 *    that lost its registration other than the I_T
2902 			 *    nexus on which the PERSISTENT RESERVE OUT command
2903 			 *    was received, with the additional sense code set
2904 			 *    to REGISTRATIONS PREEMPTED.
2905 			 */
2906 			if (!all_reg) {
2907 				if (pr_reg->pr_res_key != sa_res_key)
2908 					continue;
2909 				sa_res_key_unmatched = false;
2910 
2911 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2912 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2913 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2914 				__core_scsi3_free_registration(dev, pr_reg,
2915 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2916 						NULL, calling_it_nexus);
2917 			} else {
2918 				/*
2919 				 * Case for any existing all registrants type
2920 				 * reservation, follow logic in spc4r17 section
2921 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2922 				 *
2923 				 * For a ZERO SA Reservation key, release
2924 				 * all other registrations and do an implicit
2925 				 * release of active persistent reservation.
2926 				 *
2927 				 * For a non-ZERO SA Reservation key, only
2928 				 * release the matching reservation key from
2929 				 * registrations.
2930 				 */
2931 				if ((sa_res_key) &&
2932 				     (pr_reg->pr_res_key != sa_res_key))
2933 					continue;
2934 				sa_res_key_unmatched = false;
2935 
2936 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2937 				if (calling_it_nexus)
2938 					continue;
2939 
2940 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2941 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2942 				__core_scsi3_free_registration(dev, pr_reg,
2943 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2944 						NULL, 0);
2945 			}
2946 			if (!calling_it_nexus)
2947 				target_ua_allocate_lun(pr_reg_nacl,
2948 					pr_res_mapped_lun, 0x2A,
2949 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2950 		}
2951 		spin_unlock(&pr_tmpl->registration_lock);
2952 		/*
2953 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2954 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2955 		 * RESERVATION KEY field to a value that does not match any
2956 		 * registered reservation key, then the device server shall
2957 		 * complete the command with RESERVATION CONFLICT status.
2958 		 */
2959 		if (sa_res_key_unmatched) {
2960 			spin_unlock(&dev->dev_reservation_lock);
2961 			core_scsi3_put_pr_reg(pr_reg_n);
2962 			return TCM_RESERVATION_CONFLICT;
2963 		}
2964 		/*
2965 		 * For an existing all registrants type reservation
2966 		 * with a zero SA rservation key, preempt the existing
2967 		 * reservation with the new PR type and scope.
2968 		 */
2969 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2970 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2971 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2972 				type, scope, preempt_type);
2973 
2974 			if (preempt_type == PREEMPT_AND_ABORT)
2975 				core_scsi3_release_preempt_and_abort(
2976 					&preempt_and_abort_list, pr_reg_n);
2977 		}
2978 		spin_unlock(&dev->dev_reservation_lock);
2979 
2980 		if (pr_tmpl->pr_aptpl_active)
2981 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2982 
2983 		core_scsi3_put_pr_reg(pr_reg_n);
2984 		core_scsi3_pr_generation(cmd->se_dev);
2985 		return 0;
2986 	}
2987 	/*
2988 	 * The PREEMPTing SA reservation key matches that of the
2989 	 * existing persistent reservation, first, we check if
2990 	 * we are preempting our own reservation.
2991 	 * From spc4r17, section 5.7.11.4.3 Preempting
2992 	 * persistent reservations and registration handling
2993 	 *
2994 	 * If an all registrants persistent reservation is not
2995 	 * present, it is not an error for the persistent
2996 	 * reservation holder to preempt itself (i.e., a
2997 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
2998 	 * or a PREEMPT AND ABORT service action with the
2999 	 * SERVICE ACTION RESERVATION KEY value equal to the
3000 	 * persistent reservation holder's reservation key that
3001 	 * is received from the persistent reservation holder).
3002 	 * In that case, the device server shall establish the
3003 	 * new persistent reservation and maintain the
3004 	 * registration.
3005 	 */
3006 	prh_type = pr_res_holder->pr_res_type;
3007 	prh_scope = pr_res_holder->pr_res_scope;
3008 	/*
3009 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3010 	 * persistent reservation holder (see 5.7.10), the device
3011 	 * server shall perform a preempt by doing the following as
3012 	 * an uninterrupted series of actions:
3013 	 *
3014 	 * a) Release the persistent reservation for the holder
3015 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3016 	 */
3017 	if (pr_reg_n != pr_res_holder)
3018 		__core_scsi3_complete_pro_release(dev,
3019 						  pr_res_holder->pr_reg_nacl,
3020 						  dev->dev_pr_res_holder, 0, 0);
3021 	/*
3022 	 * b) Remove the registrations for all I_T nexuses identified
3023 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3024 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3025 	 *    OUT command. If an all registrants persistent reservation
3026 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3027 	 *    is set to zero, then all registrations shall be removed
3028 	 *    except for that of the I_T nexus that is being used for
3029 	 *    the PERSISTENT RESERVE OUT command;
3030 	 */
3031 	spin_lock(&pr_tmpl->registration_lock);
3032 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3033 			&pr_tmpl->registration_list, pr_reg_list) {
3034 
3035 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3036 		if (calling_it_nexus)
3037 			continue;
3038 
3039 		if (pr_reg->pr_res_key != sa_res_key)
3040 			continue;
3041 
3042 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3043 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3044 		__core_scsi3_free_registration(dev, pr_reg,
3045 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3046 				calling_it_nexus);
3047 		/*
3048 		 * e) Establish a unit attention condition for the initiator
3049 		 *    port associated with every I_T nexus that lost its
3050 		 *    persistent reservation and/or registration, with the
3051 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3052 		 */
3053 		target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3054 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3055 	}
3056 	spin_unlock(&pr_tmpl->registration_lock);
3057 	/*
3058 	 * c) Establish a persistent reservation for the preempting
3059 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3060 	 */
3061 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3062 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3063 			type, scope, preempt_type);
3064 	/*
3065 	 * d) Process tasks as defined in 5.7.1;
3066 	 * e) See above..
3067 	 * f) If the type or scope has changed, then for every I_T nexus
3068 	 *    whose reservation key was not removed, except for the I_T
3069 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3070 	 *    received, the device server shall establish a unit
3071 	 *    attention condition for the initiator port associated with
3072 	 *    that I_T nexus, with the additional sense code set to
3073 	 *    RESERVATIONS RELEASED. If the type or scope have not
3074 	 *    changed, then no unit attention condition(s) shall be
3075 	 *    established for this reason.
3076 	 */
3077 	if ((prh_type != type) || (prh_scope != scope)) {
3078 		spin_lock(&pr_tmpl->registration_lock);
3079 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3080 				&pr_tmpl->registration_list, pr_reg_list) {
3081 
3082 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3083 			if (calling_it_nexus)
3084 				continue;
3085 
3086 			target_ua_allocate_lun(pr_reg->pr_reg_nacl,
3087 					pr_reg->pr_res_mapped_lun, 0x2A,
3088 					ASCQ_2AH_RESERVATIONS_RELEASED);
3089 		}
3090 		spin_unlock(&pr_tmpl->registration_lock);
3091 	}
3092 	spin_unlock(&dev->dev_reservation_lock);
3093 	/*
3094 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3095 	 * All received CDBs for the matching existing reservation and
3096 	 * registrations undergo ABORT_TASK logic.
3097 	 *
3098 	 * From there, core_scsi3_release_preempt_and_abort() will
3099 	 * release every registration in the list (which have already
3100 	 * been removed from the primary pr_reg list), except the
3101 	 * new persistent reservation holder, the calling Initiator Port.
3102 	 */
3103 	if (preempt_type == PREEMPT_AND_ABORT) {
3104 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3105 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3106 						pr_reg_n);
3107 	}
3108 
3109 	if (pr_tmpl->pr_aptpl_active)
3110 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3111 
3112 	core_scsi3_put_pr_reg(pr_reg_n);
3113 	core_scsi3_pr_generation(cmd->se_dev);
3114 	return 0;
3115 }
3116 
3117 static sense_reason_t
3118 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3119 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3120 {
3121 	switch (type) {
3122 	case PR_TYPE_WRITE_EXCLUSIVE:
3123 	case PR_TYPE_EXCLUSIVE_ACCESS:
3124 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3125 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3126 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3127 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3128 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3129 					      sa_res_key, preempt_type);
3130 	default:
3131 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3132 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3133 		return TCM_INVALID_CDB_FIELD;
3134 	}
3135 }
3136 
3137 
3138 static sense_reason_t
3139 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3140 		u64 sa_res_key, int aptpl, int unreg)
3141 {
3142 	struct se_session *se_sess = cmd->se_sess;
3143 	struct se_device *dev = cmd->se_dev;
3144 	struct se_dev_entry *dest_se_deve = NULL;
3145 	struct se_lun *se_lun = cmd->se_lun, *tmp_lun;
3146 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3147 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3148 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3149 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3150 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3151 	unsigned char *buf;
3152 	const unsigned char *initiator_str;
3153 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
3154 	u32 tid_len, tmp_tid_len;
3155 	int new_reg = 0, type, scope, matching_iname;
3156 	sense_reason_t ret;
3157 	unsigned short rtpi;
3158 	unsigned char proto_ident;
3159 
3160 	if (!se_sess || !se_lun) {
3161 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3162 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3163 	}
3164 
3165 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3166 	se_tpg = se_sess->se_tpg;
3167 	tf_ops = se_tpg->se_tpg_tfo;
3168 	/*
3169 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3170 	 *	Register behaviors for a REGISTER AND MOVE service action
3171 	 *
3172 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3173 	 */
3174 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3175 				se_sess);
3176 	if (!pr_reg) {
3177 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3178 			" *pr_reg for REGISTER_AND_MOVE\n");
3179 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3180 	}
3181 	/*
3182 	 * The provided reservation key much match the existing reservation key
3183 	 * provided during this initiator's I_T nexus registration.
3184 	 */
3185 	if (res_key != pr_reg->pr_res_key) {
3186 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3187 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3188 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3189 		ret = TCM_RESERVATION_CONFLICT;
3190 		goto out_put_pr_reg;
3191 	}
3192 	/*
3193 	 * The service active reservation key needs to be non zero
3194 	 */
3195 	if (!sa_res_key) {
3196 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3197 			" sa_res_key\n");
3198 		ret = TCM_INVALID_PARAMETER_LIST;
3199 		goto out_put_pr_reg;
3200 	}
3201 
3202 	/*
3203 	 * Determine the Relative Target Port Identifier where the reservation
3204 	 * will be moved to for the TransportID containing SCSI initiator WWN
3205 	 * information.
3206 	 */
3207 	buf = transport_kmap_data_sg(cmd);
3208 	if (!buf) {
3209 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3210 		goto out_put_pr_reg;
3211 	}
3212 
3213 	rtpi = get_unaligned_be16(&buf[18]);
3214 	tid_len = get_unaligned_be32(&buf[20]);
3215 	transport_kunmap_data_sg(cmd);
3216 	buf = NULL;
3217 
3218 	if ((tid_len + 24) != cmd->data_length) {
3219 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3220 			" does not equal CDB data_length: %u\n", tid_len,
3221 			cmd->data_length);
3222 		ret = TCM_INVALID_PARAMETER_LIST;
3223 		goto out_put_pr_reg;
3224 	}
3225 
3226 	spin_lock(&dev->se_port_lock);
3227 	list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
3228 		if (tmp_lun->lun_rtpi != rtpi)
3229 			continue;
3230 		dest_se_tpg = tmp_lun->lun_tpg;
3231 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3232 		if (!dest_tf_ops)
3233 			continue;
3234 
3235 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3236 		spin_unlock(&dev->se_port_lock);
3237 
3238 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3239 			pr_err("core_scsi3_tpg_depend_item() failed"
3240 				" for dest_se_tpg\n");
3241 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3242 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3243 			goto out_put_pr_reg;
3244 		}
3245 
3246 		spin_lock(&dev->se_port_lock);
3247 		break;
3248 	}
3249 	spin_unlock(&dev->se_port_lock);
3250 
3251 	if (!dest_se_tpg || !dest_tf_ops) {
3252 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3253 			" fabric ops from Relative Target Port Identifier:"
3254 			" %hu\n", rtpi);
3255 		ret = TCM_INVALID_PARAMETER_LIST;
3256 		goto out_put_pr_reg;
3257 	}
3258 
3259 	buf = transport_kmap_data_sg(cmd);
3260 	if (!buf) {
3261 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3262 		goto out_put_pr_reg;
3263 	}
3264 	proto_ident = (buf[24] & 0x0f);
3265 
3266 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3267 			" 0x%02x\n", proto_ident);
3268 
3269 	if (proto_ident != dest_se_tpg->proto_id) {
3270 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3271 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3272 			" from fabric: %s\n", proto_ident,
3273 			dest_se_tpg->proto_id,
3274 			dest_tf_ops->fabric_name);
3275 		ret = TCM_INVALID_PARAMETER_LIST;
3276 		goto out;
3277 	}
3278 	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
3279 			&buf[24], &tmp_tid_len, &iport_ptr);
3280 	if (!initiator_str) {
3281 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3282 			" initiator_str from Transport ID\n");
3283 		ret = TCM_INVALID_PARAMETER_LIST;
3284 		goto out;
3285 	}
3286 
3287 	transport_kunmap_data_sg(cmd);
3288 	buf = NULL;
3289 
3290 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3291 		" %s\n", dest_tf_ops->fabric_name, (iport_ptr != NULL) ?
3292 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3293 		iport_ptr : "");
3294 	/*
3295 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3296 	 * action specifies a TransportID that is the same as the initiator port
3297 	 * of the I_T nexus for the command received, then the command shall
3298 	 * be terminated with CHECK CONDITION status, with the sense key set to
3299 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3300 	 * IN PARAMETER LIST.
3301 	 */
3302 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3303 	matching_iname = (!strcmp(initiator_str,
3304 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3305 	if (!matching_iname)
3306 		goto after_iport_check;
3307 
3308 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3309 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3310 			" matches: %s on received I_T Nexus\n", initiator_str,
3311 			pr_reg_nacl->initiatorname);
3312 		ret = TCM_INVALID_PARAMETER_LIST;
3313 		goto out;
3314 	}
3315 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3316 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3317 			" matches: %s %s on received I_T Nexus\n",
3318 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3319 			pr_reg->pr_reg_isid);
3320 		ret = TCM_INVALID_PARAMETER_LIST;
3321 		goto out;
3322 	}
3323 after_iport_check:
3324 	/*
3325 	 * Locate the destination struct se_node_acl from the received Transport ID
3326 	 */
3327 	mutex_lock(&dest_se_tpg->acl_node_mutex);
3328 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3329 				initiator_str);
3330 	if (dest_node_acl)
3331 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3332 	mutex_unlock(&dest_se_tpg->acl_node_mutex);
3333 
3334 	if (!dest_node_acl) {
3335 		pr_err("Unable to locate %s dest_node_acl for"
3336 			" TransportID%s\n", dest_tf_ops->fabric_name,
3337 			initiator_str);
3338 		ret = TCM_INVALID_PARAMETER_LIST;
3339 		goto out;
3340 	}
3341 
3342 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3343 		pr_err("core_scsi3_nodeacl_depend_item() for"
3344 			" dest_node_acl\n");
3345 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3346 		dest_node_acl = NULL;
3347 		ret = TCM_INVALID_PARAMETER_LIST;
3348 		goto out;
3349 	}
3350 
3351 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3352 		" %s from TransportID\n", dest_tf_ops->fabric_name,
3353 		dest_node_acl->initiatorname);
3354 
3355 	/*
3356 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3357 	 * PORT IDENTIFIER.
3358 	 */
3359 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3360 	if (!dest_se_deve) {
3361 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3362 			" %hu\n",  dest_tf_ops->fabric_name, rtpi);
3363 		ret = TCM_INVALID_PARAMETER_LIST;
3364 		goto out;
3365 	}
3366 
3367 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3368 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3369 		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
3370 		dest_se_deve = NULL;
3371 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3372 		goto out;
3373 	}
3374 
3375 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3376 		" ACL for dest_se_deve->mapped_lun: %llu\n",
3377 		dest_tf_ops->fabric_name, dest_node_acl->initiatorname,
3378 		dest_se_deve->mapped_lun);
3379 
3380 	/*
3381 	 * A persistent reservation needs to already existing in order to
3382 	 * successfully complete the REGISTER_AND_MOVE service action..
3383 	 */
3384 	spin_lock(&dev->dev_reservation_lock);
3385 	pr_res_holder = dev->dev_pr_res_holder;
3386 	if (!pr_res_holder) {
3387 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3388 			" currently held\n");
3389 		spin_unlock(&dev->dev_reservation_lock);
3390 		ret = TCM_INVALID_CDB_FIELD;
3391 		goto out;
3392 	}
3393 	/*
3394 	 * The received on I_T Nexus must be the reservation holder.
3395 	 *
3396 	 * From spc4r17 section 5.7.8  Table 50 --
3397 	 * 	Register behaviors for a REGISTER AND MOVE service action
3398 	 */
3399 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3400 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3401 			" Nexus is not reservation holder\n");
3402 		spin_unlock(&dev->dev_reservation_lock);
3403 		ret = TCM_RESERVATION_CONFLICT;
3404 		goto out;
3405 	}
3406 	/*
3407 	 * From spc4r17 section 5.7.8: registering and moving reservation
3408 	 *
3409 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3410 	 * action is received and the established persistent reservation is a
3411 	 * Write Exclusive - All Registrants type or Exclusive Access -
3412 	 * All Registrants type reservation, then the command shall be completed
3413 	 * with RESERVATION CONFLICT status.
3414 	 */
3415 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3416 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3417 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3418 			" reservation for type: %s\n",
3419 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3420 		spin_unlock(&dev->dev_reservation_lock);
3421 		ret = TCM_RESERVATION_CONFLICT;
3422 		goto out;
3423 	}
3424 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3425 	/*
3426 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3427 	 */
3428 	type = pr_res_holder->pr_res_type;
3429 	scope = pr_res_holder->pr_res_type;
3430 	/*
3431 	 * c) Associate the reservation key specified in the SERVICE ACTION
3432 	 *    RESERVATION KEY field with the I_T nexus specified as the
3433 	 *    destination of the register and move, where:
3434 	 *    A) The I_T nexus is specified by the TransportID and the
3435 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3436 	 *    B) Regardless of the TransportID format used, the association for
3437 	 *       the initiator port is based on either the initiator port name
3438 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3439 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3440 	 *       transport protocols where port names are not required;
3441 	 * d) Register the reservation key specified in the SERVICE ACTION
3442 	 *    RESERVATION KEY field;
3443 	 * e) Retain the reservation key specified in the SERVICE ACTION
3444 	 *    RESERVATION KEY field and associated information;
3445 	 *
3446 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3447 	 * register an I_T nexus that is already registered with the same
3448 	 * reservation key or a different reservation key.
3449 	 */
3450 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3451 					iport_ptr);
3452 	if (!dest_pr_reg) {
3453 		struct se_lun *dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
3454 				kref_read(&dest_se_deve->pr_kref) != 0);
3455 
3456 		spin_unlock(&dev->dev_reservation_lock);
3457 		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
3458 					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
3459 					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
3460 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3461 			goto out;
3462 		}
3463 		spin_lock(&dev->dev_reservation_lock);
3464 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3465 						iport_ptr);
3466 		new_reg = 1;
3467 	}
3468 	/*
3469 	 * f) Release the persistent reservation for the persistent reservation
3470 	 *    holder (i.e., the I_T nexus on which the
3471 	 */
3472 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3473 					  dev->dev_pr_res_holder, 0, 0);
3474 	/*
3475 	 * g) Move the persistent reservation to the specified I_T nexus using
3476 	 *    the same scope and type as the persistent reservation released in
3477 	 *    item f); and
3478 	 */
3479 	dev->dev_pr_res_holder = dest_pr_reg;
3480 	dest_pr_reg->pr_res_holder = 1;
3481 	dest_pr_reg->pr_res_type = type;
3482 	pr_reg->pr_res_scope = scope;
3483 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3484 	/*
3485 	 * Increment PRGeneration for existing registrations..
3486 	 */
3487 	if (!new_reg)
3488 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3489 	spin_unlock(&dev->dev_reservation_lock);
3490 
3491 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3492 		" created new reservation holder TYPE: %s on object RTPI:"
3493 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->fabric_name,
3494 		core_scsi3_pr_dump_type(type), rtpi,
3495 		dest_pr_reg->pr_res_generation);
3496 	pr_debug("SPC-3 PR Successfully moved reservation from"
3497 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3498 		tf_ops->fabric_name, pr_reg_nacl->initiatorname,
3499 		i_buf, dest_tf_ops->fabric_name,
3500 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3501 		iport_ptr : "");
3502 	/*
3503 	 * It is now safe to release configfs group dependencies for destination
3504 	 * of Transport ID Initiator Device/Port Identifier
3505 	 */
3506 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3507 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3508 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3509 	/*
3510 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3511 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3512 	 */
3513 	if (unreg) {
3514 		spin_lock(&pr_tmpl->registration_lock);
3515 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3516 		spin_unlock(&pr_tmpl->registration_lock);
3517 	} else
3518 		core_scsi3_put_pr_reg(pr_reg);
3519 
3520 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3521 
3522 	core_scsi3_put_pr_reg(dest_pr_reg);
3523 	return 0;
3524 out:
3525 	if (buf)
3526 		transport_kunmap_data_sg(cmd);
3527 	if (dest_se_deve)
3528 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3529 	if (dest_node_acl)
3530 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3531 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3532 
3533 out_put_pr_reg:
3534 	core_scsi3_put_pr_reg(pr_reg);
3535 	return ret;
3536 }
3537 
3538 /*
3539  * See spc4r17 section 6.14 Table 170
3540  */
3541 sense_reason_t
3542 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3543 {
3544 	struct se_device *dev = cmd->se_dev;
3545 	unsigned char *cdb = &cmd->t_task_cdb[0];
3546 	unsigned char *buf;
3547 	u64 res_key, sa_res_key;
3548 	int sa, scope, type, aptpl;
3549 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3550 	sense_reason_t ret;
3551 
3552 	/*
3553 	 * Following spc2r20 5.5.1 Reservations overview:
3554 	 *
3555 	 * If a logical unit has been reserved by any RESERVE command and is
3556 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3557 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3558 	 * initiator or service action and shall terminate with a RESERVATION
3559 	 * CONFLICT status.
3560 	 */
3561 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3562 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3563 			" SPC-2 reservation is held, returning"
3564 			" RESERVATION_CONFLICT\n");
3565 		return TCM_RESERVATION_CONFLICT;
3566 	}
3567 
3568 	/*
3569 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3570 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3571 	 */
3572 	if (!cmd->se_sess)
3573 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3574 
3575 	if (cmd->data_length < 24) {
3576 		pr_warn("SPC-PR: Received PR OUT parameter list"
3577 			" length too small: %u\n", cmd->data_length);
3578 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3579 	}
3580 
3581 	/*
3582 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3583 	 */
3584 	sa = (cdb[1] & 0x1f);
3585 	scope = (cdb[2] & 0xf0);
3586 	type = (cdb[2] & 0x0f);
3587 
3588 	buf = transport_kmap_data_sg(cmd);
3589 	if (!buf)
3590 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3591 
3592 	/*
3593 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3594 	 */
3595 	res_key = get_unaligned_be64(&buf[0]);
3596 	sa_res_key = get_unaligned_be64(&buf[8]);
3597 	/*
3598 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3599 	 * SCSI TransportIDs.
3600 	 */
3601 	if (sa != PRO_REGISTER_AND_MOVE) {
3602 		spec_i_pt = (buf[20] & 0x08);
3603 		all_tg_pt = (buf[20] & 0x04);
3604 		aptpl = (buf[20] & 0x01);
3605 	} else {
3606 		aptpl = (buf[17] & 0x01);
3607 		unreg = (buf[17] & 0x02);
3608 	}
3609 	/*
3610 	 * If the backend device has been configured to force APTPL metadata
3611 	 * write-out, go ahead and propigate aptpl=1 down now.
3612 	 */
3613 	if (dev->dev_attrib.force_pr_aptpl)
3614 		aptpl = 1;
3615 
3616 	transport_kunmap_data_sg(cmd);
3617 	buf = NULL;
3618 
3619 	/*
3620 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3621 	 */
3622 	if (spec_i_pt && (sa != PRO_REGISTER))
3623 		return TCM_INVALID_PARAMETER_LIST;
3624 
3625 	/*
3626 	 * From spc4r17 section 6.14:
3627 	 *
3628 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3629 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3630 	 * the command shall be terminated with CHECK CONDITION status, with
3631 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3632 	 * code set to PARAMETER LIST LENGTH ERROR.
3633 	 */
3634 	if (!spec_i_pt && (sa != PRO_REGISTER_AND_MOVE) &&
3635 	    (cmd->data_length != 24)) {
3636 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3637 			" list length: %u\n", cmd->data_length);
3638 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3639 	}
3640 
3641 	/*
3642 	 * (core_scsi3_emulate_pro_* function parameters
3643 	 * are defined by spc4r17 Table 174:
3644 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3645 	 */
3646 	switch (sa) {
3647 	case PRO_REGISTER:
3648 		ret = core_scsi3_emulate_pro_register(cmd,
3649 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3650 		break;
3651 	case PRO_RESERVE:
3652 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3653 		break;
3654 	case PRO_RELEASE:
3655 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3656 		break;
3657 	case PRO_CLEAR:
3658 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3659 		break;
3660 	case PRO_PREEMPT:
3661 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3662 					res_key, sa_res_key, PREEMPT);
3663 		break;
3664 	case PRO_PREEMPT_AND_ABORT:
3665 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3666 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3667 		break;
3668 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3669 		ret = core_scsi3_emulate_pro_register(cmd,
3670 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3671 		break;
3672 	case PRO_REGISTER_AND_MOVE:
3673 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3674 				sa_res_key, aptpl, unreg);
3675 		break;
3676 	default:
3677 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3678 			" action: 0x%02x\n", sa);
3679 		return TCM_INVALID_CDB_FIELD;
3680 	}
3681 
3682 	if (!ret)
3683 		target_complete_cmd(cmd, GOOD);
3684 	return ret;
3685 }
3686 
3687 /*
3688  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3689  *
3690  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3691  */
3692 static sense_reason_t
3693 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3694 {
3695 	struct se_device *dev = cmd->se_dev;
3696 	struct t10_pr_registration *pr_reg;
3697 	unsigned char *buf;
3698 	u32 add_len = 0, off = 8;
3699 
3700 	if (cmd->data_length < 8) {
3701 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3702 			" too small\n", cmd->data_length);
3703 		return TCM_INVALID_CDB_FIELD;
3704 	}
3705 
3706 	buf = transport_kmap_data_sg(cmd);
3707 	if (!buf)
3708 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3709 
3710 	put_unaligned_be32(dev->t10_pr.pr_generation, buf);
3711 
3712 	spin_lock(&dev->t10_pr.registration_lock);
3713 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3714 			pr_reg_list) {
3715 		/*
3716 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3717 		 * next reservation key list descriptor.
3718 		 */
3719 		if (off + 8 <= cmd->data_length) {
3720 			put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3721 			off += 8;
3722 		}
3723 		/*
3724 		 * SPC5r17: 6.16.2 READ KEYS service action
3725 		 * The ADDITIONAL LENGTH field indicates the number of bytes in
3726 		 * the Reservation key list. The contents of the ADDITIONAL
3727 		 * LENGTH field are not altered based on the allocation length
3728 		 */
3729 		add_len += 8;
3730 	}
3731 	spin_unlock(&dev->t10_pr.registration_lock);
3732 
3733 	put_unaligned_be32(add_len, &buf[4]);
3734 
3735 	transport_kunmap_data_sg(cmd);
3736 
3737 	return 0;
3738 }
3739 
3740 /*
3741  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3742  *
3743  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3744  */
3745 static sense_reason_t
3746 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3747 {
3748 	struct se_device *dev = cmd->se_dev;
3749 	struct t10_pr_registration *pr_reg;
3750 	unsigned char *buf;
3751 	u64 pr_res_key;
3752 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3753 
3754 	if (cmd->data_length < 8) {
3755 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3756 			" too small\n", cmd->data_length);
3757 		return TCM_INVALID_CDB_FIELD;
3758 	}
3759 
3760 	buf = transport_kmap_data_sg(cmd);
3761 	if (!buf)
3762 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3763 
3764 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3765 
3766 	spin_lock(&dev->dev_reservation_lock);
3767 	pr_reg = dev->dev_pr_res_holder;
3768 	if (pr_reg) {
3769 		/*
3770 		 * Set the hardcoded Additional Length
3771 		 */
3772 		put_unaligned_be32(add_len, &buf[4]);
3773 
3774 		if (cmd->data_length < 22)
3775 			goto err;
3776 
3777 		/*
3778 		 * Set the Reservation key.
3779 		 *
3780 		 * From spc4r17, section 5.7.10:
3781 		 * A persistent reservation holder has its reservation key
3782 		 * returned in the parameter data from a PERSISTENT
3783 		 * RESERVE IN command with READ RESERVATION service action as
3784 		 * follows:
3785 		 * a) For a persistent reservation of the type Write Exclusive
3786 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3787 		 *      the reservation key shall be set to zero; or
3788 		 * b) For all other persistent reservation types, the
3789 		 *    reservation key shall be set to the registered
3790 		 *    reservation key for the I_T nexus that holds the
3791 		 *    persistent reservation.
3792 		 */
3793 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3794 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3795 			pr_res_key = 0;
3796 		else
3797 			pr_res_key = pr_reg->pr_res_key;
3798 
3799 		put_unaligned_be64(pr_res_key, &buf[8]);
3800 		/*
3801 		 * Set the SCOPE and TYPE
3802 		 */
3803 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3804 			  (pr_reg->pr_res_type & 0x0f);
3805 	}
3806 
3807 err:
3808 	spin_unlock(&dev->dev_reservation_lock);
3809 	transport_kunmap_data_sg(cmd);
3810 
3811 	return 0;
3812 }
3813 
3814 /*
3815  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3816  *
3817  * See spc4r17 section 6.13.4 Table 165
3818  */
3819 static sense_reason_t
3820 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3821 {
3822 	struct se_device *dev = cmd->se_dev;
3823 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3824 	unsigned char *buf;
3825 	u16 add_len = 8; /* Hardcoded to 8. */
3826 
3827 	if (cmd->data_length < 6) {
3828 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3829 			" %u too small\n", cmd->data_length);
3830 		return TCM_INVALID_CDB_FIELD;
3831 	}
3832 
3833 	buf = transport_kmap_data_sg(cmd);
3834 	if (!buf)
3835 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3836 
3837 	put_unaligned_be16(add_len, &buf[0]);
3838 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3839 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3840 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3841 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3842 	/*
3843 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3844 	 * set the TMV: Task Mask Valid bit.
3845 	 */
3846 	buf[3] |= 0x80;
3847 	/*
3848 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3849 	 */
3850 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3851 	/*
3852 	 * PTPL_A: Persistence across Target Power Loss Active bit
3853 	 */
3854 	if (pr_tmpl->pr_aptpl_active)
3855 		buf[3] |= 0x01;
3856 	/*
3857 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3858 	 */
3859 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3860 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3861 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3862 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3863 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3864 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3865 
3866 	transport_kunmap_data_sg(cmd);
3867 
3868 	return 0;
3869 }
3870 
3871 /*
3872  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3873  *
3874  * See spc4r17 section 6.13.5 Table 168 and 169
3875  */
3876 static sense_reason_t
3877 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3878 {
3879 	struct se_device *dev = cmd->se_dev;
3880 	struct se_node_acl *se_nacl;
3881 	struct se_portal_group *se_tpg;
3882 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3883 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3884 	unsigned char *buf;
3885 	u32 add_desc_len = 0, add_len = 0;
3886 	u32 off = 8; /* off into first Full Status descriptor */
3887 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3888 	int exp_desc_len, desc_len;
3889 	bool all_reg = false;
3890 
3891 	if (cmd->data_length < 8) {
3892 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3893 			" too small\n", cmd->data_length);
3894 		return TCM_INVALID_CDB_FIELD;
3895 	}
3896 
3897 	buf = transport_kmap_data_sg(cmd);
3898 	if (!buf)
3899 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3900 
3901 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3902 
3903 	spin_lock(&dev->dev_reservation_lock);
3904 	if (dev->dev_pr_res_holder) {
3905 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3906 
3907 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3908 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3909 			all_reg = true;
3910 			pr_res_type = pr_holder->pr_res_type;
3911 			pr_res_scope = pr_holder->pr_res_scope;
3912 		}
3913 	}
3914 	spin_unlock(&dev->dev_reservation_lock);
3915 
3916 	spin_lock(&pr_tmpl->registration_lock);
3917 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3918 			&pr_tmpl->registration_list, pr_reg_list) {
3919 
3920 		se_nacl = pr_reg->pr_reg_nacl;
3921 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3922 		add_desc_len = 0;
3923 
3924 		atomic_inc_mb(&pr_reg->pr_res_holders);
3925 		spin_unlock(&pr_tmpl->registration_lock);
3926 		/*
3927 		 * Determine expected length of $FABRIC_MOD specific
3928 		 * TransportID full status descriptor..
3929 		 */
3930 		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
3931 					&format_code);
3932 		if (exp_desc_len < 0 ||
3933 		    exp_desc_len + add_len > cmd->data_length) {
3934 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3935 				" out of buffer: %d\n", cmd->data_length);
3936 			spin_lock(&pr_tmpl->registration_lock);
3937 			atomic_dec_mb(&pr_reg->pr_res_holders);
3938 			break;
3939 		}
3940 		/*
3941 		 * Set RESERVATION KEY
3942 		 */
3943 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3944 		off += 8;
3945 		off += 4; /* Skip Over Reserved area */
3946 
3947 		/*
3948 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3949 		 */
3950 		if (pr_reg->pr_reg_all_tg_pt)
3951 			buf[off] = 0x02;
3952 		/*
3953 		 * The struct se_lun pointer will be present for the
3954 		 * reservation holder for PR_HOLDER bit.
3955 		 *
3956 		 * Also, if this registration is the reservation
3957 		 * holder or there is an All Registrants reservation
3958 		 * active, fill in SCOPE and TYPE in the next byte.
3959 		 */
3960 		if (pr_reg->pr_res_holder) {
3961 			buf[off++] |= 0x01;
3962 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3963 				     (pr_reg->pr_res_type & 0x0f);
3964 		} else if (all_reg) {
3965 			buf[off++] |= 0x01;
3966 			buf[off++] = (pr_res_scope & 0xf0) |
3967 				     (pr_res_type & 0x0f);
3968 		} else {
3969 			off += 2;
3970 		}
3971 
3972 		off += 4; /* Skip over reserved area */
3973 		/*
3974 		 * From spc4r17 6.3.15:
3975 		 *
3976 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
3977 		 * IDENTIFIER field contains the relative port identifier (see
3978 		 * 3.1.120) of the target port that is part of the I_T nexus
3979 		 * described by this full status descriptor. If the ALL_TG_PT
3980 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
3981 		 * IDENTIFIER field are not defined by this standard.
3982 		 */
3983 		if (!pr_reg->pr_reg_all_tg_pt) {
3984 			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;
3985 
3986 			put_unaligned_be16(sep_rtpi, &buf[off]);
3987 			off += 2;
3988 		} else
3989 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
3990 
3991 		buf[off+4] = se_tpg->proto_id;
3992 
3993 		/*
3994 		 * Now, have the $FABRIC_MOD fill in the transport ID.
3995 		 */
3996 		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
3997 				&format_code, &buf[off+4]);
3998 
3999 		spin_lock(&pr_tmpl->registration_lock);
4000 		atomic_dec_mb(&pr_reg->pr_res_holders);
4001 
4002 		if (desc_len < 0)
4003 			break;
4004 		/*
4005 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4006 		 */
4007 		put_unaligned_be32(desc_len, &buf[off]);
4008 		off += 4;
4009 		/*
4010 		 * Size of full desctipor header minus TransportID
4011 		 * containing $FABRIC_MOD specific) initiator device/port
4012 		 * WWN information.
4013 		 *
4014 		 *  See spc4r17 Section 6.13.5 Table 169
4015 		 */
4016 		add_desc_len = (24 + desc_len);
4017 
4018 		off += desc_len;
4019 		add_len += add_desc_len;
4020 	}
4021 	spin_unlock(&pr_tmpl->registration_lock);
4022 	/*
4023 	 * Set ADDITIONAL_LENGTH
4024 	 */
4025 	put_unaligned_be32(add_len, &buf[4]);
4026 
4027 	transport_kunmap_data_sg(cmd);
4028 
4029 	return 0;
4030 }
4031 
4032 sense_reason_t
4033 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4034 {
4035 	sense_reason_t ret;
4036 
4037 	/*
4038 	 * Following spc2r20 5.5.1 Reservations overview:
4039 	 *
4040 	 * If a logical unit has been reserved by any RESERVE command and is
4041 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4042 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4043 	 * initiator or service action and shall terminate with a RESERVATION
4044 	 * CONFLICT status.
4045 	 */
4046 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4047 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4048 			" SPC-2 reservation is held, returning"
4049 			" RESERVATION_CONFLICT\n");
4050 		return TCM_RESERVATION_CONFLICT;
4051 	}
4052 
4053 	switch (cmd->t_task_cdb[1] & 0x1f) {
4054 	case PRI_READ_KEYS:
4055 		ret = core_scsi3_pri_read_keys(cmd);
4056 		break;
4057 	case PRI_READ_RESERVATION:
4058 		ret = core_scsi3_pri_read_reservation(cmd);
4059 		break;
4060 	case PRI_REPORT_CAPABILITIES:
4061 		ret = core_scsi3_pri_report_capabilities(cmd);
4062 		break;
4063 	case PRI_READ_FULL_STATUS:
4064 		ret = core_scsi3_pri_read_full_status(cmd);
4065 		break;
4066 	default:
4067 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4068 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4069 		return TCM_INVALID_CDB_FIELD;
4070 	}
4071 
4072 	if (!ret)
4073 		target_complete_cmd(cmd, GOOD);
4074 	return ret;
4075 }
4076 
4077 sense_reason_t
4078 target_check_reservation(struct se_cmd *cmd)
4079 {
4080 	struct se_device *dev = cmd->se_dev;
4081 	sense_reason_t ret;
4082 
4083 	if (!cmd->se_sess)
4084 		return 0;
4085 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4086 		return 0;
4087 	if (!dev->dev_attrib.emulate_pr)
4088 		return 0;
4089 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
4090 		return 0;
4091 
4092 	spin_lock(&dev->dev_reservation_lock);
4093 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4094 		ret = target_scsi2_reservation_check(cmd);
4095 	else
4096 		ret = target_scsi3_pr_reservation_check(cmd);
4097 	spin_unlock(&dev->dev_reservation_lock);
4098 
4099 	return ret;
4100 }
4101