xref: /linux/drivers/target/target_core_pr.c (revision 26fbb4c8c7c3ee9a4c3b4de555a8587b5a19154e)
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 		fallthrough;
341 	case PR_TYPE_EXCLUSIVE_ACCESS:
342 		/*
343 		 * Some commands are only allowed for the persistent reservation
344 		 * holder.
345 		 */
346 		break;
347 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
348 		we = 1;
349 		fallthrough;
350 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
351 		/*
352 		 * Some commands are only allowed for registered I_T Nexuses.
353 		 */
354 		reg_only = 1;
355 		break;
356 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
357 		we = 1;
358 		fallthrough;
359 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
360 		/*
361 		 * Each registered I_T Nexus is a reservation holder.
362 		 */
363 		all_reg = 1;
364 		break;
365 	default:
366 		return -EINVAL;
367 	}
368 	/*
369 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
370 	 */
371 	switch (cdb[0]) {
372 	case SECURITY_PROTOCOL_IN:
373 		if (registered_nexus)
374 			return 0;
375 		ret = (we) ? 0 : 1;
376 		break;
377 	case MODE_SENSE:
378 	case MODE_SENSE_10:
379 	case READ_ATTRIBUTE:
380 	case READ_BUFFER:
381 	case RECEIVE_DIAGNOSTIC:
382 		if (legacy) {
383 			ret = 1;
384 			break;
385 		}
386 		if (registered_nexus) {
387 			ret = 0;
388 			break;
389 		}
390 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
391 		break;
392 	case PERSISTENT_RESERVE_OUT:
393 		/*
394 		 * This follows PERSISTENT_RESERVE_OUT service actions that
395 		 * are allowed in the presence of various reservations.
396 		 * See spc4r17, table 46
397 		 */
398 		switch (cdb[1] & 0x1f) {
399 		case PRO_CLEAR:
400 		case PRO_PREEMPT:
401 		case PRO_PREEMPT_AND_ABORT:
402 			ret = (registered_nexus) ? 0 : 1;
403 			break;
404 		case PRO_REGISTER:
405 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
406 			ret = 0;
407 			break;
408 		case PRO_REGISTER_AND_MOVE:
409 		case PRO_RESERVE:
410 			ret = 1;
411 			break;
412 		case PRO_RELEASE:
413 			ret = (registered_nexus) ? 0 : 1;
414 			break;
415 		default:
416 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
417 				" action: 0x%02x\n", cdb[1] & 0x1f);
418 			return -EINVAL;
419 		}
420 		break;
421 	case RELEASE:
422 	case RELEASE_10:
423 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
424 		ret = 0;
425 		break;
426 	case RESERVE:
427 	case RESERVE_10:
428 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
429 		ret = 0;
430 		break;
431 	case TEST_UNIT_READY:
432 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
433 		break;
434 	case MAINTENANCE_IN:
435 		switch (cdb[1] & 0x1f) {
436 		case MI_MANAGEMENT_PROTOCOL_IN:
437 			if (registered_nexus) {
438 				ret = 0;
439 				break;
440 			}
441 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
442 			break;
443 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
444 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
445 			if (legacy) {
446 				ret = 1;
447 				break;
448 			}
449 			if (registered_nexus) {
450 				ret = 0;
451 				break;
452 			}
453 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
454 			break;
455 		case MI_REPORT_ALIASES:
456 		case MI_REPORT_IDENTIFYING_INFORMATION:
457 		case MI_REPORT_PRIORITY:
458 		case MI_REPORT_TARGET_PGS:
459 		case MI_REPORT_TIMESTAMP:
460 			ret = 0; /* Allowed */
461 			break;
462 		default:
463 			pr_err("Unknown MI Service Action: 0x%02x\n",
464 				(cdb[1] & 0x1f));
465 			return -EINVAL;
466 		}
467 		break;
468 	case ACCESS_CONTROL_IN:
469 	case ACCESS_CONTROL_OUT:
470 	case INQUIRY:
471 	case LOG_SENSE:
472 	case SERVICE_ACTION_IN_12:
473 	case REPORT_LUNS:
474 	case REQUEST_SENSE:
475 	case PERSISTENT_RESERVE_IN:
476 		ret = 0; /*/ Allowed CDBs */
477 		break;
478 	default:
479 		other_cdb = 1;
480 		break;
481 	}
482 	/*
483 	 * Case where the CDB is explicitly allowed in the above switch
484 	 * statement.
485 	 */
486 	if (!ret && !other_cdb) {
487 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
488 			" reservation holder\n", cdb[0],
489 			core_scsi3_pr_dump_type(pr_reg_type));
490 
491 		return ret;
492 	}
493 	/*
494 	 * Check if write exclusive initiator ports *NOT* holding the
495 	 * WRITE_EXCLUSIVE_* reservation.
496 	 */
497 	if (we && !registered_nexus) {
498 		if (cmd->data_direction == DMA_TO_DEVICE) {
499 			/*
500 			 * Conflict for write exclusive
501 			 */
502 			pr_debug("%s Conflict for unregistered nexus"
503 				" %s CDB: 0x%02x to %s reservation\n",
504 				transport_dump_cmd_direction(cmd),
505 				se_sess->se_node_acl->initiatorname, cdb[0],
506 				core_scsi3_pr_dump_type(pr_reg_type));
507 			return 1;
508 		} else {
509 			/*
510 			 * Allow non WRITE CDBs for all Write Exclusive
511 			 * PR TYPEs to pass for registered and
512 			 * non-registered_nexuxes NOT holding the reservation.
513 			 *
514 			 * We only make noise for the unregisterd nexuses,
515 			 * as we expect registered non-reservation holding
516 			 * nexuses to issue CDBs.
517 			 */
518 
519 			if (!registered_nexus) {
520 				pr_debug("Allowing implicit CDB: 0x%02x"
521 					" for %s reservation on unregistered"
522 					" nexus\n", cdb[0],
523 					core_scsi3_pr_dump_type(pr_reg_type));
524 			}
525 
526 			return 0;
527 		}
528 	} else if ((reg_only) || (all_reg)) {
529 		if (registered_nexus) {
530 			/*
531 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
532 			 * allow commands from registered nexuses.
533 			 */
534 
535 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
536 				" reservation\n", cdb[0],
537 				core_scsi3_pr_dump_type(pr_reg_type));
538 
539 			return 0;
540 		}
541        } else if (we && registered_nexus) {
542                /*
543                 * Reads are allowed for Write Exclusive locks
544                 * from all registrants.
545                 */
546                if (cmd->data_direction == DMA_FROM_DEVICE) {
547                        pr_debug("Allowing READ CDB: 0x%02x for %s"
548                                " reservation\n", cdb[0],
549                                core_scsi3_pr_dump_type(pr_reg_type));
550 
551                        return 0;
552                }
553 	}
554 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
555 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
556 		(registered_nexus) ? "" : "un",
557 		se_sess->se_node_acl->initiatorname, cdb[0],
558 		core_scsi3_pr_dump_type(pr_reg_type));
559 
560 	return 1; /* Conflict by default */
561 }
562 
563 static sense_reason_t
564 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
565 {
566 	struct se_device *dev = cmd->se_dev;
567 	struct se_session *sess = cmd->se_sess;
568 	u32 pr_reg_type;
569 	bool isid_mismatch = false;
570 
571 	if (!dev->dev_pr_res_holder)
572 		return 0;
573 
574 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
575 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
576 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
577 		goto check_nonholder;
578 
579 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
580 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
581 		    sess->sess_bin_isid) {
582 			isid_mismatch = true;
583 			goto check_nonholder;
584 		}
585 	}
586 
587 	return 0;
588 
589 check_nonholder:
590 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type, isid_mismatch))
591 		return TCM_RESERVATION_CONFLICT;
592 	return 0;
593 }
594 
595 static u32 core_scsi3_pr_generation(struct se_device *dev)
596 {
597 	u32 prg;
598 
599 	/*
600 	 * PRGeneration field shall contain the value of a 32-bit wrapping
601 	 * counter mainted by the device server.
602 	 *
603 	 * Note that this is done regardless of Active Persist across
604 	 * Target PowerLoss (APTPL)
605 	 *
606 	 * See spc4r17 section 6.3.12 READ_KEYS service action
607 	 */
608 	spin_lock(&dev->dev_reservation_lock);
609 	prg = dev->t10_pr.pr_generation++;
610 	spin_unlock(&dev->dev_reservation_lock);
611 
612 	return prg;
613 }
614 
615 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
616 	struct se_device *dev,
617 	struct se_node_acl *nacl,
618 	struct se_lun *lun,
619 	struct se_dev_entry *dest_deve,
620 	u64 mapped_lun,
621 	unsigned char *isid,
622 	u64 sa_res_key,
623 	int all_tg_pt,
624 	int aptpl)
625 {
626 	struct t10_pr_registration *pr_reg;
627 
628 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
629 	if (!pr_reg) {
630 		pr_err("Unable to allocate struct t10_pr_registration\n");
631 		return NULL;
632 	}
633 
634 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
635 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
636 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
637 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
638 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
639 	atomic_set(&pr_reg->pr_res_holders, 0);
640 	pr_reg->pr_reg_nacl = nacl;
641 	/*
642 	 * For destination registrations for ALL_TG_PT=1 and SPEC_I_PT=1,
643 	 * the se_dev_entry->pr_ref will have been already obtained by
644 	 * core_get_se_deve_from_rtpi() or __core_scsi3_alloc_registration().
645 	 *
646 	 * Otherwise, locate se_dev_entry now and obtain a reference until
647 	 * registration completes in __core_scsi3_add_registration().
648 	 */
649 	if (dest_deve) {
650 		pr_reg->pr_reg_deve = dest_deve;
651 	} else {
652 		rcu_read_lock();
653 		pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
654 		if (!pr_reg->pr_reg_deve) {
655 			rcu_read_unlock();
656 			pr_err("Unable to locate PR deve %s mapped_lun: %llu\n",
657 				nacl->initiatorname, mapped_lun);
658 			kmem_cache_free(t10_pr_reg_cache, pr_reg);
659 			return NULL;
660 		}
661 		kref_get(&pr_reg->pr_reg_deve->pr_kref);
662 		rcu_read_unlock();
663 	}
664 	pr_reg->pr_res_mapped_lun = mapped_lun;
665 	pr_reg->pr_aptpl_target_lun = lun->unpacked_lun;
666 	pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
667 	pr_reg->pr_res_key = sa_res_key;
668 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
669 	pr_reg->pr_reg_aptpl = aptpl;
670 	/*
671 	 * If an ISID value for this SCSI Initiator Port exists,
672 	 * save it to the registration now.
673 	 */
674 	if (isid != NULL) {
675 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
676 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
677 		pr_reg->isid_present_at_reg = 1;
678 	}
679 
680 	return pr_reg;
681 }
682 
683 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
684 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
685 
686 /*
687  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
688  * modes.
689  */
690 static struct t10_pr_registration *__core_scsi3_alloc_registration(
691 	struct se_device *dev,
692 	struct se_node_acl *nacl,
693 	struct se_lun *lun,
694 	struct se_dev_entry *deve,
695 	u64 mapped_lun,
696 	unsigned char *isid,
697 	u64 sa_res_key,
698 	int all_tg_pt,
699 	int aptpl)
700 {
701 	struct se_dev_entry *deve_tmp;
702 	struct se_node_acl *nacl_tmp;
703 	struct se_lun_acl *lacl_tmp;
704 	struct se_lun *lun_tmp, *next, *dest_lun;
705 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
706 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
707 	int ret;
708 	/*
709 	 * Create a registration for the I_T Nexus upon which the
710 	 * PROUT REGISTER was received.
711 	 */
712 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, lun, deve, mapped_lun,
713 						    isid, sa_res_key, all_tg_pt,
714 						    aptpl);
715 	if (!pr_reg)
716 		return NULL;
717 	/*
718 	 * Return pointer to pr_reg for ALL_TG_PT=0
719 	 */
720 	if (!all_tg_pt)
721 		return pr_reg;
722 	/*
723 	 * Create list of matching SCSI Initiator Port registrations
724 	 * for ALL_TG_PT=1
725 	 */
726 	spin_lock(&dev->se_port_lock);
727 	list_for_each_entry_safe(lun_tmp, next, &dev->dev_sep_list, lun_dev_link) {
728 		if (!percpu_ref_tryget_live(&lun_tmp->lun_ref))
729 			continue;
730 		spin_unlock(&dev->se_port_lock);
731 
732 		spin_lock(&lun_tmp->lun_deve_lock);
733 		list_for_each_entry(deve_tmp, &lun_tmp->lun_deve_list, lun_link) {
734 			/*
735 			 * This pointer will be NULL for demo mode MappedLUNs
736 			 * that have not been make explicit via a ConfigFS
737 			 * MappedLUN group for the SCSI Initiator Node ACL.
738 			 */
739 			if (!deve_tmp->se_lun_acl)
740 				continue;
741 
742 			lacl_tmp = rcu_dereference_check(deve_tmp->se_lun_acl,
743 						lockdep_is_held(&lun_tmp->lun_deve_lock));
744 			nacl_tmp = lacl_tmp->se_lun_nacl;
745 			/*
746 			 * Skip the matching struct se_node_acl that is allocated
747 			 * above..
748 			 */
749 			if (nacl == nacl_tmp)
750 				continue;
751 			/*
752 			 * Only perform PR registrations for target ports on
753 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
754 			 * arrived.
755 			 */
756 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
757 				continue;
758 			/*
759 			 * Look for a matching Initiator Node ACL in ASCII format
760 			 */
761 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
762 				continue;
763 
764 			kref_get(&deve_tmp->pr_kref);
765 			spin_unlock(&lun_tmp->lun_deve_lock);
766 			/*
767 			 * Grab a configfs group dependency that is released
768 			 * for the exception path at label out: below, or upon
769 			 * completion of adding ALL_TG_PT=1 registrations in
770 			 * __core_scsi3_add_registration()
771 			 */
772 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
773 			if (ret < 0) {
774 				pr_err("core_scsi3_lunacl_depend"
775 						"_item() failed\n");
776 				percpu_ref_put(&lun_tmp->lun_ref);
777 				kref_put(&deve_tmp->pr_kref, target_pr_kref_release);
778 				goto out;
779 			}
780 			/*
781 			 * Located a matching SCSI Initiator Port on a different
782 			 * port, allocate the pr_reg_atp and attach it to the
783 			 * pr_reg->pr_reg_atp_list that will be processed once
784 			 * the original *pr_reg is processed in
785 			 * __core_scsi3_add_registration()
786 			 */
787 			dest_lun = rcu_dereference_check(deve_tmp->se_lun,
788 				kref_read(&deve_tmp->pr_kref) != 0);
789 
790 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
791 						nacl_tmp, dest_lun, deve_tmp,
792 						deve_tmp->mapped_lun, NULL,
793 						sa_res_key, all_tg_pt, aptpl);
794 			if (!pr_reg_atp) {
795 				percpu_ref_put(&lun_tmp->lun_ref);
796 				core_scsi3_lunacl_undepend_item(deve_tmp);
797 				goto out;
798 			}
799 
800 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
801 				      &pr_reg->pr_reg_atp_list);
802 			spin_lock(&lun_tmp->lun_deve_lock);
803 		}
804 		spin_unlock(&lun_tmp->lun_deve_lock);
805 
806 		spin_lock(&dev->se_port_lock);
807 		percpu_ref_put(&lun_tmp->lun_ref);
808 	}
809 	spin_unlock(&dev->se_port_lock);
810 
811 	return pr_reg;
812 out:
813 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
814 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
815 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
816 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
817 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
818 	}
819 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
820 	return NULL;
821 }
822 
823 int core_scsi3_alloc_aptpl_registration(
824 	struct t10_reservation *pr_tmpl,
825 	u64 sa_res_key,
826 	unsigned char *i_port,
827 	unsigned char *isid,
828 	u64 mapped_lun,
829 	unsigned char *t_port,
830 	u16 tpgt,
831 	u64 target_lun,
832 	int res_holder,
833 	int all_tg_pt,
834 	u8 type)
835 {
836 	struct t10_pr_registration *pr_reg;
837 
838 	if (!i_port || !t_port || !sa_res_key) {
839 		pr_err("Illegal parameters for APTPL registration\n");
840 		return -EINVAL;
841 	}
842 
843 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
844 	if (!pr_reg) {
845 		pr_err("Unable to allocate struct t10_pr_registration\n");
846 		return -ENOMEM;
847 	}
848 
849 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
850 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
851 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
852 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
853 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
854 	atomic_set(&pr_reg->pr_res_holders, 0);
855 	pr_reg->pr_reg_nacl = NULL;
856 	pr_reg->pr_reg_deve = NULL;
857 	pr_reg->pr_res_mapped_lun = mapped_lun;
858 	pr_reg->pr_aptpl_target_lun = target_lun;
859 	pr_reg->pr_res_key = sa_res_key;
860 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
861 	pr_reg->pr_reg_aptpl = 1;
862 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
863 	pr_reg->pr_res_type = type;
864 	/*
865 	 * If an ISID value had been saved in APTPL metadata for this
866 	 * SCSI Initiator Port, restore it now.
867 	 */
868 	if (isid != NULL) {
869 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
870 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
871 		pr_reg->isid_present_at_reg = 1;
872 	}
873 	/*
874 	 * Copy the i_port and t_port information from caller.
875 	 */
876 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
877 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
878 	pr_reg->pr_reg_tpgt = tpgt;
879 	/*
880 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
881 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
882 	 * the Initiator Node LUN ACL from the fabric module is created for
883 	 * this registration.
884 	 */
885 	pr_reg->pr_res_holder = res_holder;
886 
887 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
888 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
889 			" metadata\n", (res_holder) ? "+reservation" : "");
890 	return 0;
891 }
892 
893 static void core_scsi3_aptpl_reserve(
894 	struct se_device *dev,
895 	struct se_portal_group *tpg,
896 	struct se_node_acl *node_acl,
897 	struct t10_pr_registration *pr_reg)
898 {
899 	char i_buf[PR_REG_ISID_ID_LEN];
900 
901 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
902 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
903 
904 	spin_lock(&dev->dev_reservation_lock);
905 	dev->dev_pr_res_holder = pr_reg;
906 	spin_unlock(&dev->dev_reservation_lock);
907 
908 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
909 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
910 		tpg->se_tpg_tfo->fabric_name,
911 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
912 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
913 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
914 		tpg->se_tpg_tfo->fabric_name, node_acl->initiatorname,
915 		i_buf);
916 }
917 
918 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
919 				struct t10_pr_registration *, enum register_type, int);
920 
921 static int __core_scsi3_check_aptpl_registration(
922 	struct se_device *dev,
923 	struct se_portal_group *tpg,
924 	struct se_lun *lun,
925 	u64 target_lun,
926 	struct se_node_acl *nacl,
927 	u64 mapped_lun)
928 {
929 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
930 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
931 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
932 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
933 	u16 tpgt;
934 
935 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
936 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
937 	/*
938 	 * Copy Initiator Port information from struct se_node_acl
939 	 */
940 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
941 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
942 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
943 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
944 	/*
945 	 * Look for the matching registrations+reservation from those
946 	 * created from APTPL metadata.  Note that multiple registrations
947 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
948 	 * TransportIDs.
949 	 */
950 	spin_lock(&pr_tmpl->aptpl_reg_lock);
951 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
952 				pr_reg_aptpl_list) {
953 
954 		if (!strcmp(pr_reg->pr_iport, i_port) &&
955 		     (pr_reg->pr_res_mapped_lun == mapped_lun) &&
956 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
957 		     (pr_reg->pr_reg_tpgt == tpgt) &&
958 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
959 			/*
960 			 * Obtain the ->pr_reg_deve pointer + reference, that
961 			 * is released by __core_scsi3_add_registration() below.
962 			 */
963 			rcu_read_lock();
964 			pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
965 			if (!pr_reg->pr_reg_deve) {
966 				pr_err("Unable to locate PR APTPL %s mapped_lun:"
967 					" %llu\n", nacl->initiatorname, mapped_lun);
968 				rcu_read_unlock();
969 				continue;
970 			}
971 			kref_get(&pr_reg->pr_reg_deve->pr_kref);
972 			rcu_read_unlock();
973 
974 			pr_reg->pr_reg_nacl = nacl;
975 			pr_reg->tg_pt_sep_rtpi = lun->lun_rtpi;
976 			list_del(&pr_reg->pr_reg_aptpl_list);
977 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
978 			/*
979 			 * At this point all of the pointers in *pr_reg will
980 			 * be setup, so go ahead and add the registration.
981 			 */
982 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
983 			/*
984 			 * If this registration is the reservation holder,
985 			 * make that happen now..
986 			 */
987 			if (pr_reg->pr_res_holder)
988 				core_scsi3_aptpl_reserve(dev, tpg,
989 						nacl, pr_reg);
990 			/*
991 			 * Reenable pr_aptpl_active to accept new metadata
992 			 * updates once the SCSI device is active again..
993 			 */
994 			spin_lock(&pr_tmpl->aptpl_reg_lock);
995 			pr_tmpl->pr_aptpl_active = 1;
996 		}
997 	}
998 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
999 
1000 	return 0;
1001 }
1002 
1003 int core_scsi3_check_aptpl_registration(
1004 	struct se_device *dev,
1005 	struct se_portal_group *tpg,
1006 	struct se_lun *lun,
1007 	struct se_node_acl *nacl,
1008 	u64 mapped_lun)
1009 {
1010 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
1011 		return 0;
1012 
1013 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
1014 						     lun->unpacked_lun, nacl,
1015 						     mapped_lun);
1016 }
1017 
1018 static void __core_scsi3_dump_registration(
1019 	const struct target_core_fabric_ops *tfo,
1020 	struct se_device *dev,
1021 	struct se_node_acl *nacl,
1022 	struct t10_pr_registration *pr_reg,
1023 	enum register_type register_type)
1024 {
1025 	struct se_portal_group *se_tpg = nacl->se_tpg;
1026 	char i_buf[PR_REG_ISID_ID_LEN];
1027 
1028 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
1029 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1030 
1031 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1032 		" Node: %s%s\n", tfo->fabric_name, (register_type == REGISTER_AND_MOVE) ?
1033 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
1034 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1035 		i_buf);
1036 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1037 		 tfo->fabric_name, tfo->tpg_get_wwn(se_tpg),
1038 		tfo->tpg_get_tag(se_tpg));
1039 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1040 		" Port(s)\n",  tfo->fabric_name,
1041 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1042 		dev->transport->name);
1043 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1044 		" 0x%08x  APTPL: %d\n", tfo->fabric_name,
1045 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1046 		pr_reg->pr_reg_aptpl);
1047 }
1048 
1049 static void __core_scsi3_add_registration(
1050 	struct se_device *dev,
1051 	struct se_node_acl *nacl,
1052 	struct t10_pr_registration *pr_reg,
1053 	enum register_type register_type,
1054 	int register_move)
1055 {
1056 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1057 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1058 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1059 	struct se_dev_entry *deve;
1060 
1061 	/*
1062 	 * Increment PRgeneration counter for struct se_device upon a successful
1063 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1064 	 *
1065 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1066 	 * action, the struct se_device->dev_reservation_lock will already be held,
1067 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1068 	 * for the REGISTER.
1069 	 */
1070 	pr_reg->pr_res_generation = (register_move) ?
1071 			dev->t10_pr.pr_generation++ :
1072 			core_scsi3_pr_generation(dev);
1073 
1074 	spin_lock(&pr_tmpl->registration_lock);
1075 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1076 
1077 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1078 	spin_unlock(&pr_tmpl->registration_lock);
1079 	/*
1080 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1081 	 */
1082 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1083 		goto out;
1084 	/*
1085 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1086 	 * allocated in __core_scsi3_alloc_registration()
1087 	 */
1088 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1089 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1090 		struct se_node_acl *nacl_tmp = pr_reg_tmp->pr_reg_nacl;
1091 
1092 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1093 
1094 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1095 
1096 		spin_lock(&pr_tmpl->registration_lock);
1097 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1098 			      &pr_tmpl->registration_list);
1099 
1100 		__core_scsi3_dump_registration(tfo, dev, nacl_tmp, pr_reg_tmp,
1101 					       register_type);
1102 		spin_unlock(&pr_tmpl->registration_lock);
1103 		/*
1104 		 * Drop configfs group dependency reference and deve->pr_kref
1105 		 * obtained from  __core_scsi3_alloc_registration() code.
1106 		 */
1107 		rcu_read_lock();
1108 		deve = pr_reg_tmp->pr_reg_deve;
1109 		if (deve) {
1110 			set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1111 			core_scsi3_lunacl_undepend_item(deve);
1112 			pr_reg_tmp->pr_reg_deve = NULL;
1113 		}
1114 		rcu_read_unlock();
1115 	}
1116 out:
1117 	/*
1118 	 * Drop deve->pr_kref obtained in __core_scsi3_do_alloc_registration()
1119 	 */
1120 	rcu_read_lock();
1121 	deve = pr_reg->pr_reg_deve;
1122 	if (deve) {
1123 		set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1124 		kref_put(&deve->pr_kref, target_pr_kref_release);
1125 		pr_reg->pr_reg_deve = NULL;
1126 	}
1127 	rcu_read_unlock();
1128 }
1129 
1130 static int core_scsi3_alloc_registration(
1131 	struct se_device *dev,
1132 	struct se_node_acl *nacl,
1133 	struct se_lun *lun,
1134 	struct se_dev_entry *deve,
1135 	u64 mapped_lun,
1136 	unsigned char *isid,
1137 	u64 sa_res_key,
1138 	int all_tg_pt,
1139 	int aptpl,
1140 	enum register_type register_type,
1141 	int register_move)
1142 {
1143 	struct t10_pr_registration *pr_reg;
1144 
1145 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, lun, deve, mapped_lun,
1146 						 isid, sa_res_key, all_tg_pt,
1147 						 aptpl);
1148 	if (!pr_reg)
1149 		return -EPERM;
1150 
1151 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1152 			register_type, register_move);
1153 	return 0;
1154 }
1155 
1156 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1157 	struct se_device *dev,
1158 	struct se_node_acl *nacl,
1159 	unsigned char *isid)
1160 {
1161 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1162 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
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 		/*
1174 		 * If this registration does NOT contain a fabric provided
1175 		 * ISID, then we have found a match.
1176 		 */
1177 		if (!pr_reg->isid_present_at_reg) {
1178 			atomic_inc_mb(&pr_reg->pr_res_holders);
1179 			spin_unlock(&pr_tmpl->registration_lock);
1180 			return pr_reg;
1181 		}
1182 		/*
1183 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1184 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1185 		 * matching ISID to be provided by the local SCSI Initiator Port.
1186 		 */
1187 		if (!isid)
1188 			continue;
1189 		if (strcmp(isid, pr_reg->pr_reg_isid))
1190 			continue;
1191 
1192 		atomic_inc_mb(&pr_reg->pr_res_holders);
1193 		spin_unlock(&pr_tmpl->registration_lock);
1194 		return pr_reg;
1195 	}
1196 	spin_unlock(&pr_tmpl->registration_lock);
1197 
1198 	return NULL;
1199 }
1200 
1201 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1202 	struct se_device *dev,
1203 	struct se_node_acl *nacl,
1204 	struct se_session *sess)
1205 {
1206 	struct se_portal_group *tpg = nacl->se_tpg;
1207 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1208 
1209 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1210 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1211 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1212 					PR_REG_ISID_LEN);
1213 		isid_ptr = &buf[0];
1214 	}
1215 
1216 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1217 }
1218 
1219 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1220 {
1221 	atomic_dec_mb(&pr_reg->pr_res_holders);
1222 }
1223 
1224 static int core_scsi3_check_implicit_release(
1225 	struct se_device *dev,
1226 	struct t10_pr_registration *pr_reg)
1227 {
1228 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1229 	struct t10_pr_registration *pr_res_holder;
1230 	int ret = 0;
1231 
1232 	spin_lock(&dev->dev_reservation_lock);
1233 	pr_res_holder = dev->dev_pr_res_holder;
1234 	if (!pr_res_holder) {
1235 		spin_unlock(&dev->dev_reservation_lock);
1236 		return ret;
1237 	}
1238 	if (pr_res_holder == pr_reg) {
1239 		/*
1240 		 * Perform an implicit RELEASE if the registration that
1241 		 * is being released is holding the reservation.
1242 		 *
1243 		 * From spc4r17, section 5.7.11.1:
1244 		 *
1245 		 * e) If the I_T nexus is the persistent reservation holder
1246 		 *    and the persistent reservation is not an all registrants
1247 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1248 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1249 		 *    service action with the SERVICE ACTION RESERVATION KEY
1250 		 *    field set to zero (see 5.7.11.3).
1251 		 */
1252 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1253 		ret = 1;
1254 		/*
1255 		 * For 'All Registrants' reservation types, all existing
1256 		 * registrations are still processed as reservation holders
1257 		 * in core_scsi3_pr_seq_non_holder() after the initial
1258 		 * reservation holder is implicitly released here.
1259 		 */
1260 	} else if (pr_reg->pr_reg_all_tg_pt &&
1261 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1262 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1263 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1264 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1265 			" UNREGISTER while existing reservation with matching"
1266 			" key 0x%016Lx is present from another SCSI Initiator"
1267 			" Port\n", pr_reg->pr_res_key);
1268 		ret = -EPERM;
1269 	}
1270 	spin_unlock(&dev->dev_reservation_lock);
1271 
1272 	return ret;
1273 }
1274 
1275 static void __core_scsi3_free_registration(
1276 	struct se_device *dev,
1277 	struct t10_pr_registration *pr_reg,
1278 	struct list_head *preempt_and_abort_list,
1279 	int dec_holders)
1280 	__releases(&pr_tmpl->registration_lock)
1281 	__acquires(&pr_tmpl->registration_lock)
1282 {
1283 	const struct target_core_fabric_ops *tfo =
1284 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1285 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1286 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1287 	struct se_dev_entry *deve;
1288 	char i_buf[PR_REG_ISID_ID_LEN];
1289 
1290 	lockdep_assert_held(&pr_tmpl->registration_lock);
1291 
1292 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1293 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1294 
1295 	if (!list_empty(&pr_reg->pr_reg_list))
1296 		list_del(&pr_reg->pr_reg_list);
1297 	/*
1298 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1299 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1300 	 */
1301 	if (dec_holders)
1302 		core_scsi3_put_pr_reg(pr_reg);
1303 
1304 	spin_unlock(&pr_tmpl->registration_lock);
1305 	/*
1306 	 * Wait until all reference from any other I_T nexuses for this
1307 	 * *pr_reg have been released.  Because list_del() is called above,
1308 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1309 	 * count back to zero, and we release *pr_reg.
1310 	 */
1311 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1312 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1313 				tfo->fabric_name);
1314 		cpu_relax();
1315 	}
1316 
1317 	rcu_read_lock();
1318 	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
1319 	if (deve)
1320 		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1321 	rcu_read_unlock();
1322 
1323 	spin_lock(&pr_tmpl->registration_lock);
1324 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1325 		" Node: %s%s\n", tfo->fabric_name,
1326 		pr_reg->pr_reg_nacl->initiatorname,
1327 		i_buf);
1328 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1329 		" Port(s)\n", tfo->fabric_name,
1330 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1331 		dev->transport->name);
1332 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1333 		" 0x%08x\n", tfo->fabric_name, pr_reg->pr_res_key,
1334 		pr_reg->pr_res_generation);
1335 
1336 	if (!preempt_and_abort_list) {
1337 		pr_reg->pr_reg_deve = NULL;
1338 		pr_reg->pr_reg_nacl = NULL;
1339 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1340 		return;
1341 	}
1342 	/*
1343 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1344 	 * are released once the ABORT_TASK_SET has completed..
1345 	 */
1346 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1347 }
1348 
1349 void core_scsi3_free_pr_reg_from_nacl(
1350 	struct se_device *dev,
1351 	struct se_node_acl *nacl)
1352 {
1353 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1354 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1355 	bool free_reg = false;
1356 	/*
1357 	 * If the passed se_node_acl matches the reservation holder,
1358 	 * release the reservation.
1359 	 */
1360 	spin_lock(&dev->dev_reservation_lock);
1361 	pr_res_holder = dev->dev_pr_res_holder;
1362 	if ((pr_res_holder != NULL) &&
1363 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1364 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1365 		free_reg = true;
1366 	}
1367 	spin_unlock(&dev->dev_reservation_lock);
1368 	/*
1369 	 * Release any registration associated with the struct se_node_acl.
1370 	 */
1371 	spin_lock(&pr_tmpl->registration_lock);
1372 	if (pr_res_holder && free_reg)
1373 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1374 
1375 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1376 			&pr_tmpl->registration_list, pr_reg_list) {
1377 
1378 		if (pr_reg->pr_reg_nacl != nacl)
1379 			continue;
1380 
1381 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1382 	}
1383 	spin_unlock(&pr_tmpl->registration_lock);
1384 }
1385 
1386 void core_scsi3_free_all_registrations(
1387 	struct se_device *dev)
1388 {
1389 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1390 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1391 
1392 	spin_lock(&dev->dev_reservation_lock);
1393 	pr_res_holder = dev->dev_pr_res_holder;
1394 	if (pr_res_holder != NULL) {
1395 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1396 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1397 						  pr_res_holder, 0, 0);
1398 	}
1399 	spin_unlock(&dev->dev_reservation_lock);
1400 
1401 	spin_lock(&pr_tmpl->registration_lock);
1402 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1403 			&pr_tmpl->registration_list, pr_reg_list) {
1404 
1405 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1406 	}
1407 	spin_unlock(&pr_tmpl->registration_lock);
1408 
1409 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1410 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1411 				pr_reg_aptpl_list) {
1412 		list_del(&pr_reg->pr_reg_aptpl_list);
1413 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1414 	}
1415 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1416 }
1417 
1418 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1419 {
1420 	return target_depend_item(&tpg->tpg_group.cg_item);
1421 }
1422 
1423 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1424 {
1425 	target_undepend_item(&tpg->tpg_group.cg_item);
1426 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1427 }
1428 
1429 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1430 {
1431 	if (nacl->dynamic_node_acl)
1432 		return 0;
1433 	return target_depend_item(&nacl->acl_group.cg_item);
1434 }
1435 
1436 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1437 {
1438 	if (!nacl->dynamic_node_acl)
1439 		target_undepend_item(&nacl->acl_group.cg_item);
1440 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1441 }
1442 
1443 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1444 {
1445 	struct se_lun_acl *lun_acl;
1446 
1447 	/*
1448 	 * For nacl->dynamic_node_acl=1
1449 	 */
1450 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1451 				kref_read(&se_deve->pr_kref) != 0);
1452 	if (!lun_acl)
1453 		return 0;
1454 
1455 	return target_depend_item(&lun_acl->se_lun_group.cg_item);
1456 }
1457 
1458 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1459 {
1460 	struct se_lun_acl *lun_acl;
1461 
1462 	/*
1463 	 * For nacl->dynamic_node_acl=1
1464 	 */
1465 	lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
1466 				kref_read(&se_deve->pr_kref) != 0);
1467 	if (!lun_acl) {
1468 		kref_put(&se_deve->pr_kref, target_pr_kref_release);
1469 		return;
1470 	}
1471 
1472 	target_undepend_item(&lun_acl->se_lun_group.cg_item);
1473 	kref_put(&se_deve->pr_kref, target_pr_kref_release);
1474 }
1475 
1476 static sense_reason_t
1477 core_scsi3_decode_spec_i_port(
1478 	struct se_cmd *cmd,
1479 	struct se_portal_group *tpg,
1480 	unsigned char *l_isid,
1481 	u64 sa_res_key,
1482 	int all_tg_pt,
1483 	int aptpl)
1484 {
1485 	struct se_device *dev = cmd->se_dev;
1486 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1487 	struct se_session *se_sess = cmd->se_sess;
1488 	struct se_node_acl *dest_node_acl = NULL;
1489 	struct se_dev_entry *dest_se_deve = NULL;
1490 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1491 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1492 	LIST_HEAD(tid_dest_list);
1493 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1494 	unsigned char *buf, *ptr, proto_ident;
1495 	const unsigned char *i_str = NULL;
1496 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1497 	sense_reason_t ret;
1498 	u32 tpdl, tid_len = 0;
1499 	u32 dest_rtpi = 0;
1500 
1501 	/*
1502 	 * Allocate a struct pr_transport_id_holder and setup the
1503 	 * local_node_acl pointer and add to struct list_head tid_dest_list
1504 	 * for add registration processing in the loop of tid_dest_list below.
1505 	 */
1506 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1507 	if (!tidh_new) {
1508 		pr_err("Unable to allocate tidh_new\n");
1509 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1510 	}
1511 	INIT_LIST_HEAD(&tidh_new->dest_list);
1512 	tidh_new->dest_tpg = tpg;
1513 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1514 
1515 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1516 				se_sess->se_node_acl, cmd->se_lun,
1517 				NULL, cmd->orig_fe_lun, l_isid,
1518 				sa_res_key, all_tg_pt, aptpl);
1519 	if (!local_pr_reg) {
1520 		kfree(tidh_new);
1521 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1522 	}
1523 
1524 	if (core_scsi3_lunacl_depend_item(local_pr_reg->pr_reg_deve)) {
1525 		kfree(tidh_new);
1526 		kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1527 			 target_pr_kref_release);
1528 		kmem_cache_free(t10_pr_reg_cache, local_pr_reg);
1529 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1530 	}
1531 
1532 	tidh_new->dest_pr_reg = local_pr_reg;
1533 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1534 
1535 	if (cmd->data_length < 28) {
1536 		pr_warn("SPC-PR: Received PR OUT parameter list"
1537 			" length too small: %u\n", cmd->data_length);
1538 		ret = TCM_INVALID_PARAMETER_LIST;
1539 		goto out;
1540 	}
1541 
1542 	buf = transport_kmap_data_sg(cmd);
1543 	if (!buf) {
1544 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1545 		goto out;
1546 	}
1547 
1548 	/*
1549 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1550 	 * first extract TransportID Parameter Data Length, and make sure
1551 	 * the value matches up to the SCSI expected data transfer length.
1552 	 */
1553 	tpdl = get_unaligned_be32(&buf[24]);
1554 
1555 	if ((tpdl + 28) != cmd->data_length) {
1556 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1557 			" does not equal CDB data_length: %u\n", tpdl,
1558 			cmd->data_length);
1559 		ret = TCM_INVALID_PARAMETER_LIST;
1560 		goto out_unmap;
1561 	}
1562 	/*
1563 	 * Start processing the received transport IDs using the
1564 	 * receiving I_T Nexus portal's fabric dependent methods to
1565 	 * obtain the SCSI Initiator Port/Device Identifiers.
1566 	 */
1567 	ptr = &buf[28];
1568 
1569 	while (tpdl > 0) {
1570 		struct se_lun *dest_lun, *tmp_lun;
1571 
1572 		proto_ident = (ptr[0] & 0x0f);
1573 		dest_tpg = NULL;
1574 
1575 		spin_lock(&dev->se_port_lock);
1576 		list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
1577 			tmp_tpg = tmp_lun->lun_tpg;
1578 
1579 			/*
1580 			 * Look for the matching proto_ident provided by
1581 			 * the received TransportID
1582 			 */
1583 			if (tmp_tpg->proto_id != proto_ident)
1584 				continue;
1585 			dest_rtpi = tmp_lun->lun_rtpi;
1586 
1587 			iport_ptr = NULL;
1588 			i_str = target_parse_pr_out_transport_id(tmp_tpg,
1589 					ptr, &tid_len, &iport_ptr);
1590 			if (!i_str)
1591 				continue;
1592 			/*
1593 			 * Determine if this SCSI device server requires that
1594 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1595 			 * for fabric modules (iSCSI) requiring them.
1596 			 */
1597 			if (tpg->se_tpg_tfo->sess_get_initiator_sid &&
1598 			    dev->dev_attrib.enforce_pr_isids &&
1599 			    !iport_ptr) {
1600 				pr_warn("SPC-PR: enforce_pr_isids is set but a isid has not been sent in the SPEC_I_PT data for %s.",
1601 					i_str);
1602 				ret = TCM_INVALID_PARAMETER_LIST;
1603 				spin_unlock(&dev->se_port_lock);
1604 				goto out_unmap;
1605 			}
1606 
1607 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1608 			spin_unlock(&dev->se_port_lock);
1609 
1610 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1611 				pr_err(" core_scsi3_tpg_depend_item()"
1612 					" for tmp_tpg\n");
1613 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1614 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1615 				goto out_unmap;
1616 			}
1617 			/*
1618 			 * Locate the destination initiator ACL to be registered
1619 			 * from the decoded fabric module specific TransportID
1620 			 * at *i_str.
1621 			 */
1622 			mutex_lock(&tmp_tpg->acl_node_mutex);
1623 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1624 						tmp_tpg, i_str);
1625 			if (dest_node_acl)
1626 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1627 			mutex_unlock(&tmp_tpg->acl_node_mutex);
1628 
1629 			if (!dest_node_acl) {
1630 				core_scsi3_tpg_undepend_item(tmp_tpg);
1631 				spin_lock(&dev->se_port_lock);
1632 				continue;
1633 			}
1634 
1635 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1636 				pr_err("configfs_depend_item() failed"
1637 					" for dest_node_acl->acl_group\n");
1638 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1639 				core_scsi3_tpg_undepend_item(tmp_tpg);
1640 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1641 				goto out_unmap;
1642 			}
1643 
1644 			dest_tpg = tmp_tpg;
1645 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1646 				" %s Port RTPI: %hu\n",
1647 				dest_tpg->se_tpg_tfo->fabric_name,
1648 				dest_node_acl->initiatorname, dest_rtpi);
1649 
1650 			spin_lock(&dev->se_port_lock);
1651 			break;
1652 		}
1653 		spin_unlock(&dev->se_port_lock);
1654 
1655 		if (!dest_tpg) {
1656 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1657 					" dest_tpg\n");
1658 			ret = TCM_INVALID_PARAMETER_LIST;
1659 			goto out_unmap;
1660 		}
1661 
1662 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1663 			" tid_len: %d for %s + %s\n",
1664 			dest_tpg->se_tpg_tfo->fabric_name, cmd->data_length,
1665 			tpdl, tid_len, i_str, iport_ptr);
1666 
1667 		if (tid_len > tpdl) {
1668 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1669 				" %u for Transport ID: %s\n", tid_len, ptr);
1670 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1671 			core_scsi3_tpg_undepend_item(dest_tpg);
1672 			ret = TCM_INVALID_PARAMETER_LIST;
1673 			goto out_unmap;
1674 		}
1675 		/*
1676 		 * Locate the desintation struct se_dev_entry pointer for matching
1677 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1678 		 * Target Port.
1679 		 */
1680 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1681 					dest_rtpi);
1682 		if (!dest_se_deve) {
1683 			pr_err("Unable to locate %s dest_se_deve"
1684 				" from destination RTPI: %hu\n",
1685 				dest_tpg->se_tpg_tfo->fabric_name,
1686 				dest_rtpi);
1687 
1688 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1689 			core_scsi3_tpg_undepend_item(dest_tpg);
1690 			ret = TCM_INVALID_PARAMETER_LIST;
1691 			goto out_unmap;
1692 		}
1693 
1694 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1695 			pr_err("core_scsi3_lunacl_depend_item()"
1696 					" failed\n");
1697 			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
1698 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1699 			core_scsi3_tpg_undepend_item(dest_tpg);
1700 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1701 			goto out_unmap;
1702 		}
1703 
1704 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1705 			" dest_se_deve mapped_lun: %llu\n",
1706 			dest_tpg->se_tpg_tfo->fabric_name,
1707 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1708 
1709 		/*
1710 		 * Skip any TransportIDs that already have a registration for
1711 		 * this target port.
1712 		 */
1713 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1714 					iport_ptr);
1715 		if (pr_reg_e) {
1716 			core_scsi3_put_pr_reg(pr_reg_e);
1717 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1718 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1719 			core_scsi3_tpg_undepend_item(dest_tpg);
1720 			ptr += tid_len;
1721 			tpdl -= tid_len;
1722 			tid_len = 0;
1723 			continue;
1724 		}
1725 		/*
1726 		 * Allocate a struct pr_transport_id_holder and setup
1727 		 * the dest_node_acl and dest_se_deve pointers for the
1728 		 * loop below.
1729 		 */
1730 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1731 				GFP_KERNEL);
1732 		if (!tidh_new) {
1733 			pr_err("Unable to allocate tidh_new\n");
1734 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1735 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1736 			core_scsi3_tpg_undepend_item(dest_tpg);
1737 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1738 			goto out_unmap;
1739 		}
1740 		INIT_LIST_HEAD(&tidh_new->dest_list);
1741 		tidh_new->dest_tpg = dest_tpg;
1742 		tidh_new->dest_node_acl = dest_node_acl;
1743 		tidh_new->dest_se_deve = dest_se_deve;
1744 
1745 		/*
1746 		 * Allocate, but do NOT add the registration for the
1747 		 * TransportID referenced SCSI Initiator port.  This
1748 		 * done because of the following from spc4r17 in section
1749 		 * 6.14.3 wrt SPEC_I_PT:
1750 		 *
1751 		 * "If a registration fails for any initiator port (e.g., if th
1752 		 * logical unit does not have enough resources available to
1753 		 * hold the registration information), no registrations shall be
1754 		 * made, and the command shall be terminated with
1755 		 * CHECK CONDITION status."
1756 		 *
1757 		 * That means we call __core_scsi3_alloc_registration() here,
1758 		 * and then call __core_scsi3_add_registration() in the
1759 		 * 2nd loop which will never fail.
1760 		 */
1761 		dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
1762 				kref_read(&dest_se_deve->pr_kref) != 0);
1763 
1764 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1765 					dest_node_acl, dest_lun, dest_se_deve,
1766 					dest_se_deve->mapped_lun, iport_ptr,
1767 					sa_res_key, all_tg_pt, aptpl);
1768 		if (!dest_pr_reg) {
1769 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1770 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1771 			core_scsi3_tpg_undepend_item(dest_tpg);
1772 			kfree(tidh_new);
1773 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1774 			goto out_unmap;
1775 		}
1776 		tidh_new->dest_pr_reg = dest_pr_reg;
1777 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1778 
1779 		ptr += tid_len;
1780 		tpdl -= tid_len;
1781 		tid_len = 0;
1782 
1783 	}
1784 
1785 	transport_kunmap_data_sg(cmd);
1786 
1787 	/*
1788 	 * Go ahead and create a registrations from tid_dest_list for the
1789 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1790 	 * and dest_se_deve.
1791 	 *
1792 	 * The SA Reservation Key from the PROUT is set for the
1793 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1794 	 * means that the TransportID Initiator port will be
1795 	 * registered on all of the target ports in the SCSI target device
1796 	 * ALL_TG_PT=0 means the registration will only be for the
1797 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1798 	 * was received.
1799 	 */
1800 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1801 		dest_tpg = tidh->dest_tpg;
1802 		dest_node_acl = tidh->dest_node_acl;
1803 		dest_se_deve = tidh->dest_se_deve;
1804 		dest_pr_reg = tidh->dest_pr_reg;
1805 
1806 		list_del(&tidh->dest_list);
1807 		kfree(tidh);
1808 
1809 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1810 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1811 
1812 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1813 					dest_pr_reg, 0, 0);
1814 
1815 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1816 			" registered Transport ID for Node: %s%s Mapped LUN:"
1817 			" %llu\n", dest_tpg->se_tpg_tfo->fabric_name,
1818 			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
1819 			dest_se_deve->mapped_lun : 0);
1820 
1821 		if (dest_pr_reg == local_pr_reg)
1822 			continue;
1823 
1824 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1825 		core_scsi3_tpg_undepend_item(dest_tpg);
1826 	}
1827 
1828 	return 0;
1829 out_unmap:
1830 	transport_kunmap_data_sg(cmd);
1831 out:
1832 	/*
1833 	 * For the failure case, release everything from tid_dest_list
1834 	 * including *dest_pr_reg and the configfs dependances..
1835 	 */
1836 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1837 		bool is_local = false;
1838 
1839 		dest_tpg = tidh->dest_tpg;
1840 		dest_node_acl = tidh->dest_node_acl;
1841 		dest_se_deve = tidh->dest_se_deve;
1842 		dest_pr_reg = tidh->dest_pr_reg;
1843 
1844 		if (dest_pr_reg == local_pr_reg)
1845 			is_local = true;
1846 
1847 		list_del(&tidh->dest_list);
1848 		kfree(tidh);
1849 		/*
1850 		 * Release any extra ALL_TG_PT=1 registrations for
1851 		 * the SPEC_I_PT=1 case.
1852 		 */
1853 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1854 				&dest_pr_reg->pr_reg_atp_list,
1855 				pr_reg_atp_mem_list) {
1856 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1857 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1858 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1859 		}
1860 
1861 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1862 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1863 
1864 		if (is_local)
1865 			continue;
1866 
1867 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1868 		core_scsi3_tpg_undepend_item(dest_tpg);
1869 	}
1870 	return ret;
1871 }
1872 
1873 static int core_scsi3_update_aptpl_buf(
1874 	struct se_device *dev,
1875 	unsigned char *buf,
1876 	u32 pr_aptpl_buf_len)
1877 {
1878 	struct se_portal_group *tpg;
1879 	struct t10_pr_registration *pr_reg;
1880 	unsigned char tmp[512], isid_buf[32];
1881 	ssize_t len = 0;
1882 	int reg_count = 0;
1883 	int ret = 0;
1884 
1885 	spin_lock(&dev->dev_reservation_lock);
1886 	spin_lock(&dev->t10_pr.registration_lock);
1887 	/*
1888 	 * Walk the registration list..
1889 	 */
1890 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1891 			pr_reg_list) {
1892 
1893 		tmp[0] = '\0';
1894 		isid_buf[0] = '\0';
1895 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1896 		/*
1897 		 * Write out any ISID value to APTPL metadata that was included
1898 		 * in the original registration.
1899 		 */
1900 		if (pr_reg->isid_present_at_reg)
1901 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1902 					pr_reg->pr_reg_isid);
1903 		/*
1904 		 * Include special metadata if the pr_reg matches the
1905 		 * reservation holder.
1906 		 */
1907 		if (dev->dev_pr_res_holder == pr_reg) {
1908 			snprintf(tmp, 512, "PR_REG_START: %d"
1909 				"\ninitiator_fabric=%s\n"
1910 				"initiator_node=%s\n%s"
1911 				"sa_res_key=%llu\n"
1912 				"res_holder=1\nres_type=%02x\n"
1913 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1914 				"mapped_lun=%llu\n", reg_count,
1915 				tpg->se_tpg_tfo->fabric_name,
1916 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1917 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1918 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1919 				pr_reg->pr_res_mapped_lun);
1920 		} else {
1921 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1922 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1923 				"sa_res_key=%llu\nres_holder=0\n"
1924 				"res_all_tg_pt=%d\nmapped_lun=%llu\n",
1925 				reg_count, tpg->se_tpg_tfo->fabric_name,
1926 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1927 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1928 				pr_reg->pr_res_mapped_lun);
1929 		}
1930 
1931 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1932 			pr_err("Unable to update renaming APTPL metadata,"
1933 			       " reallocating larger buffer\n");
1934 			ret = -EMSGSIZE;
1935 			goto out;
1936 		}
1937 		len += sprintf(buf+len, "%s", tmp);
1938 
1939 		/*
1940 		 * Include information about the associated SCSI target port.
1941 		 */
1942 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1943 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%llu\nPR_REG_END:"
1944 			" %d\n", tpg->se_tpg_tfo->fabric_name,
1945 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1946 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1947 			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
1948 			reg_count);
1949 
1950 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1951 			pr_err("Unable to update renaming APTPL metadata,"
1952 			       " reallocating larger buffer\n");
1953 			ret = -EMSGSIZE;
1954 			goto out;
1955 		}
1956 		len += sprintf(buf+len, "%s", tmp);
1957 		reg_count++;
1958 	}
1959 
1960 	if (!reg_count)
1961 		len += sprintf(buf+len, "No Registrations or Reservations");
1962 
1963 out:
1964 	spin_unlock(&dev->t10_pr.registration_lock);
1965 	spin_unlock(&dev->dev_reservation_lock);
1966 
1967 	return ret;
1968 }
1969 
1970 static int __core_scsi3_write_aptpl_to_file(
1971 	struct se_device *dev,
1972 	unsigned char *buf)
1973 {
1974 	struct t10_wwn *wwn = &dev->t10_wwn;
1975 	struct file *file;
1976 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1977 	char *path;
1978 	u32 pr_aptpl_buf_len;
1979 	int ret;
1980 	loff_t pos = 0;
1981 
1982 	path = kasprintf(GFP_KERNEL, "%s/pr/aptpl_%s", db_root,
1983 			&wwn->unit_serial[0]);
1984 	if (!path)
1985 		return -ENOMEM;
1986 
1987 	file = filp_open(path, flags, 0600);
1988 	if (IS_ERR(file)) {
1989 		pr_err("filp_open(%s) for APTPL metadata"
1990 			" failed\n", path);
1991 		kfree(path);
1992 		return PTR_ERR(file);
1993 	}
1994 
1995 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1996 
1997 	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);
1998 
1999 	if (ret < 0)
2000 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2001 	fput(file);
2002 	kfree(path);
2003 
2004 	return (ret < 0) ? -EIO : 0;
2005 }
2006 
2007 /*
2008  * Clear the APTPL metadata if APTPL has been disabled, otherwise
2009  * write out the updated metadata to struct file for this SCSI device.
2010  */
2011 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
2012 {
2013 	unsigned char *buf;
2014 	int rc, len = PR_APTPL_BUF_LEN;
2015 
2016 	if (!aptpl) {
2017 		char *null_buf = "No Registrations or Reservations\n";
2018 
2019 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
2020 		dev->t10_pr.pr_aptpl_active = 0;
2021 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
2022 
2023 		if (rc)
2024 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2025 
2026 		return 0;
2027 	}
2028 retry:
2029 	buf = vzalloc(len);
2030 	if (!buf)
2031 		return TCM_OUT_OF_RESOURCES;
2032 
2033 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
2034 	if (rc < 0) {
2035 		vfree(buf);
2036 		len *= 2;
2037 		goto retry;
2038 	}
2039 
2040 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2041 	if (rc != 0) {
2042 		pr_err("SPC-3 PR: Could not update APTPL\n");
2043 		vfree(buf);
2044 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2045 	}
2046 	dev->t10_pr.pr_aptpl_active = 1;
2047 	vfree(buf);
2048 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2049 	return 0;
2050 }
2051 
2052 static sense_reason_t
2053 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2054 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2055 {
2056 	struct se_session *se_sess = cmd->se_sess;
2057 	struct se_device *dev = cmd->se_dev;
2058 	struct se_lun *se_lun = cmd->se_lun;
2059 	struct se_portal_group *se_tpg;
2060 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2061 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2062 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2063 	sense_reason_t ret = TCM_NO_SENSE;
2064 	int pr_holder = 0, type;
2065 
2066 	if (!se_sess || !se_lun) {
2067 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2068 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2069 	}
2070 	se_tpg = se_sess->se_tpg;
2071 
2072 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2073 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2074 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2075 				PR_REG_ISID_LEN);
2076 		isid_ptr = &isid_buf[0];
2077 	}
2078 	/*
2079 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2080 	 */
2081 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2082 	if (!pr_reg) {
2083 		if (res_key) {
2084 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2085 				" for SA REGISTER, returning CONFLICT\n");
2086 			return TCM_RESERVATION_CONFLICT;
2087 		}
2088 		/*
2089 		 * Do nothing but return GOOD status.
2090 		 */
2091 		if (!sa_res_key)
2092 			return 0;
2093 
2094 		if (!spec_i_pt) {
2095 			/*
2096 			 * Perform the Service Action REGISTER on the Initiator
2097 			 * Port Endpoint that the PRO was received from on the
2098 			 * Logical Unit of the SCSI device server.
2099 			 */
2100 			if (core_scsi3_alloc_registration(cmd->se_dev,
2101 					se_sess->se_node_acl, cmd->se_lun,
2102 					NULL, cmd->orig_fe_lun, isid_ptr,
2103 					sa_res_key, all_tg_pt, aptpl,
2104 					register_type, 0)) {
2105 				pr_err("Unable to allocate"
2106 					" struct t10_pr_registration\n");
2107 				return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
2108 			}
2109 		} else {
2110 			/*
2111 			 * Register both the Initiator port that received
2112 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2113 			 * TransportID from Parameter list and loop through
2114 			 * fabric dependent parameter list while calling
2115 			 * logic from of core_scsi3_alloc_registration() for
2116 			 * each TransportID provided SCSI Initiator Port/Device
2117 			 */
2118 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2119 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2120 			if (ret != 0)
2121 				return ret;
2122 		}
2123 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2124 	}
2125 
2126 	/* ok, existing registration */
2127 
2128 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2129 		pr_err("SPC-3 PR REGISTER: Received"
2130 		       " res_key: 0x%016Lx does not match"
2131 		       " existing SA REGISTER res_key:"
2132 		       " 0x%016Lx\n", res_key,
2133 		       pr_reg->pr_res_key);
2134 		ret = TCM_RESERVATION_CONFLICT;
2135 		goto out;
2136 	}
2137 
2138 	if (spec_i_pt) {
2139 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2140 			" set on a registered nexus\n");
2141 		ret = TCM_INVALID_PARAMETER_LIST;
2142 		goto out;
2143 	}
2144 
2145 	/*
2146 	 * An existing ALL_TG_PT=1 registration being released
2147 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2148 	 */
2149 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2150 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2151 			" registration exists, but ALL_TG_PT=1 bit not"
2152 			" present in received PROUT\n");
2153 		ret = TCM_INVALID_CDB_FIELD;
2154 		goto out;
2155 	}
2156 
2157 	/*
2158 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2159 	 */
2160 	if (sa_res_key) {
2161 		/*
2162 		 * Increment PRgeneration counter for struct se_device"
2163 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2164 		 * READ_KEYS service action.
2165 		 */
2166 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2167 		pr_reg->pr_res_key = sa_res_key;
2168 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2169 			 " Key for %s to: 0x%016Lx PRgeneration:"
2170 			 " 0x%08x\n", cmd->se_tfo->fabric_name,
2171 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2172 			 pr_reg->pr_reg_nacl->initiatorname,
2173 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2174 
2175 	} else {
2176 		/*
2177 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2178 		 */
2179 		type = pr_reg->pr_res_type;
2180 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2181 							      pr_reg);
2182 		if (pr_holder < 0) {
2183 			ret = TCM_RESERVATION_CONFLICT;
2184 			goto out;
2185 		}
2186 
2187 		spin_lock(&pr_tmpl->registration_lock);
2188 		/*
2189 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2190 		 * and matching pr_res_key.
2191 		 */
2192 		if (pr_reg->pr_reg_all_tg_pt) {
2193 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2194 					&pr_tmpl->registration_list,
2195 					pr_reg_list) {
2196 
2197 				if (!pr_reg_p->pr_reg_all_tg_pt)
2198 					continue;
2199 				if (pr_reg_p->pr_res_key != res_key)
2200 					continue;
2201 				if (pr_reg == pr_reg_p)
2202 					continue;
2203 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2204 					   pr_reg_p->pr_reg_nacl->initiatorname))
2205 					continue;
2206 
2207 				__core_scsi3_free_registration(dev,
2208 						pr_reg_p, NULL, 0);
2209 			}
2210 		}
2211 
2212 		/*
2213 		 * Release the calling I_T Nexus registration now..
2214 		 */
2215 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2216 		pr_reg = NULL;
2217 
2218 		/*
2219 		 * From spc4r17, section 5.7.11.3 Unregistering
2220 		 *
2221 		 * If the persistent reservation is a registrants only
2222 		 * type, the device server shall establish a unit
2223 		 * attention condition for the initiator port associated
2224 		 * with every registered I_T nexus except for the I_T
2225 		 * nexus on which the PERSISTENT RESERVE OUT command was
2226 		 * received, with the additional sense code set to
2227 		 * RESERVATIONS RELEASED.
2228 		 */
2229 		if (pr_holder &&
2230 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2231 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2232 			list_for_each_entry(pr_reg_p,
2233 					&pr_tmpl->registration_list,
2234 					pr_reg_list) {
2235 
2236 				target_ua_allocate_lun(
2237 					pr_reg_p->pr_reg_nacl,
2238 					pr_reg_p->pr_res_mapped_lun,
2239 					0x2A,
2240 					ASCQ_2AH_RESERVATIONS_RELEASED);
2241 			}
2242 		}
2243 
2244 		spin_unlock(&pr_tmpl->registration_lock);
2245 	}
2246 
2247 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2248 
2249 out:
2250 	if (pr_reg)
2251 		core_scsi3_put_pr_reg(pr_reg);
2252 	return ret;
2253 }
2254 
2255 unsigned char *core_scsi3_pr_dump_type(int type)
2256 {
2257 	switch (type) {
2258 	case PR_TYPE_WRITE_EXCLUSIVE:
2259 		return "Write Exclusive Access";
2260 	case PR_TYPE_EXCLUSIVE_ACCESS:
2261 		return "Exclusive Access";
2262 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2263 		return "Write Exclusive Access, Registrants Only";
2264 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2265 		return "Exclusive Access, Registrants Only";
2266 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2267 		return "Write Exclusive Access, All Registrants";
2268 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2269 		return "Exclusive Access, All Registrants";
2270 	default:
2271 		break;
2272 	}
2273 
2274 	return "Unknown SPC-3 PR Type";
2275 }
2276 
2277 static sense_reason_t
2278 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2279 {
2280 	struct se_device *dev = cmd->se_dev;
2281 	struct se_session *se_sess = cmd->se_sess;
2282 	struct se_lun *se_lun = cmd->se_lun;
2283 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2284 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2285 	char i_buf[PR_REG_ISID_ID_LEN];
2286 	sense_reason_t ret;
2287 
2288 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2289 
2290 	if (!se_sess || !se_lun) {
2291 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2292 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2293 	}
2294 	/*
2295 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2296 	 */
2297 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2298 				se_sess);
2299 	if (!pr_reg) {
2300 		pr_err("SPC-3 PR: Unable to locate"
2301 			" PR_REGISTERED *pr_reg for RESERVE\n");
2302 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2303 	}
2304 	/*
2305 	 * From spc4r17 Section 5.7.9: Reserving:
2306 	 *
2307 	 * An application client creates a persistent reservation by issuing
2308 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2309 	 * a registered I_T nexus with the following parameters:
2310 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2311 	 * 	 registered with the logical unit for the I_T nexus; and
2312 	 */
2313 	if (res_key != pr_reg->pr_res_key) {
2314 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2315 			" does not match existing SA REGISTER res_key:"
2316 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2317 		ret = TCM_RESERVATION_CONFLICT;
2318 		goto out_put_pr_reg;
2319 	}
2320 	/*
2321 	 * From spc4r17 Section 5.7.9: Reserving:
2322 	 *
2323 	 * From above:
2324 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2325 	 *     being created.
2326 	 *
2327 	 * Only one persistent reservation is allowed at a time per logical unit
2328 	 * and that persistent reservation has a scope of LU_SCOPE.
2329 	 */
2330 	if (scope != PR_SCOPE_LU_SCOPE) {
2331 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2332 		ret = TCM_INVALID_PARAMETER_LIST;
2333 		goto out_put_pr_reg;
2334 	}
2335 	/*
2336 	 * See if we have an existing PR reservation holder pointer at
2337 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2338 	 * *pr_res_holder.
2339 	 */
2340 	spin_lock(&dev->dev_reservation_lock);
2341 	pr_res_holder = dev->dev_pr_res_holder;
2342 	if (pr_res_holder) {
2343 		/*
2344 		 * From spc4r17 Section 5.7.9: Reserving:
2345 		 *
2346 		 * If the device server receives a PERSISTENT RESERVE OUT
2347 		 * command from an I_T nexus other than a persistent reservation
2348 		 * holder (see 5.7.10) that attempts to create a persistent
2349 		 * reservation when a persistent reservation already exists for
2350 		 * the logical unit, then the command shall be completed with
2351 		 * RESERVATION CONFLICT status.
2352 		 */
2353 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2354 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2355 			pr_err("SPC-3 PR: Attempted RESERVE from"
2356 				" [%s]: %s while reservation already held by"
2357 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2358 				cmd->se_tfo->fabric_name,
2359 				se_sess->se_node_acl->initiatorname,
2360 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2361 				pr_res_holder->pr_reg_nacl->initiatorname);
2362 
2363 			spin_unlock(&dev->dev_reservation_lock);
2364 			ret = TCM_RESERVATION_CONFLICT;
2365 			goto out_put_pr_reg;
2366 		}
2367 		/*
2368 		 * From spc4r17 Section 5.7.9: Reserving:
2369 		 *
2370 		 * If a persistent reservation holder attempts to modify the
2371 		 * type or scope of an existing persistent reservation, the
2372 		 * command shall be completed with RESERVATION CONFLICT status.
2373 		 */
2374 		if ((pr_res_holder->pr_res_type != type) ||
2375 		    (pr_res_holder->pr_res_scope != scope)) {
2376 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2377 			pr_err("SPC-3 PR: Attempted RESERVE from"
2378 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2379 				" while reservation already held by [%s]: %s,"
2380 				" returning RESERVATION_CONFLICT\n",
2381 				cmd->se_tfo->fabric_name,
2382 				se_sess->se_node_acl->initiatorname,
2383 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2384 				pr_res_holder->pr_reg_nacl->initiatorname);
2385 
2386 			spin_unlock(&dev->dev_reservation_lock);
2387 			ret = TCM_RESERVATION_CONFLICT;
2388 			goto out_put_pr_reg;
2389 		}
2390 		/*
2391 		 * From spc4r17 Section 5.7.9: Reserving:
2392 		 *
2393 		 * If the device server receives a PERSISTENT RESERVE OUT
2394 		 * command with RESERVE service action where the TYPE field and
2395 		 * the SCOPE field contain the same values as the existing type
2396 		 * and scope from a persistent reservation holder, it shall not
2397 		 * make any change to the existing persistent reservation and
2398 		 * shall completethe command with GOOD status.
2399 		 */
2400 		spin_unlock(&dev->dev_reservation_lock);
2401 		ret = 0;
2402 		goto out_put_pr_reg;
2403 	}
2404 	/*
2405 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2406 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2407 	 */
2408 	pr_reg->pr_res_scope = scope;
2409 	pr_reg->pr_res_type = type;
2410 	pr_reg->pr_res_holder = 1;
2411 	dev->dev_pr_res_holder = pr_reg;
2412 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2413 
2414 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2415 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2416 		cmd->se_tfo->fabric_name, core_scsi3_pr_dump_type(type),
2417 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2418 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2419 			cmd->se_tfo->fabric_name,
2420 			se_sess->se_node_acl->initiatorname,
2421 			i_buf);
2422 	spin_unlock(&dev->dev_reservation_lock);
2423 
2424 	if (pr_tmpl->pr_aptpl_active)
2425 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2426 
2427 	ret = 0;
2428 out_put_pr_reg:
2429 	core_scsi3_put_pr_reg(pr_reg);
2430 	return ret;
2431 }
2432 
2433 static sense_reason_t
2434 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2435 		u64 res_key)
2436 {
2437 	switch (type) {
2438 	case PR_TYPE_WRITE_EXCLUSIVE:
2439 	case PR_TYPE_EXCLUSIVE_ACCESS:
2440 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2441 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2442 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2443 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2444 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2445 	default:
2446 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2447 			" 0x%02x\n", type);
2448 		return TCM_INVALID_CDB_FIELD;
2449 	}
2450 }
2451 
2452 static void __core_scsi3_complete_pro_release(
2453 	struct se_device *dev,
2454 	struct se_node_acl *se_nacl,
2455 	struct t10_pr_registration *pr_reg,
2456 	int explicit,
2457 	int unreg)
2458 {
2459 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2460 	char i_buf[PR_REG_ISID_ID_LEN];
2461 	int pr_res_type = 0, pr_res_scope = 0;
2462 
2463 	lockdep_assert_held(&dev->dev_reservation_lock);
2464 
2465 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2466 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2467 	/*
2468 	 * Go ahead and release the current PR reservation holder.
2469 	 * If an All Registrants reservation is currently active and
2470 	 * a unregister operation is requested, replace the current
2471 	 * dev_pr_res_holder with another active registration.
2472 	 */
2473 	if (dev->dev_pr_res_holder) {
2474 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2475 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2476 		dev->dev_pr_res_holder->pr_res_type = 0;
2477 		dev->dev_pr_res_holder->pr_res_scope = 0;
2478 		dev->dev_pr_res_holder->pr_res_holder = 0;
2479 		dev->dev_pr_res_holder = NULL;
2480 	}
2481 	if (!unreg)
2482 		goto out;
2483 
2484 	spin_lock(&dev->t10_pr.registration_lock);
2485 	list_del_init(&pr_reg->pr_reg_list);
2486 	/*
2487 	 * If the I_T nexus is a reservation holder, the persistent reservation
2488 	 * is of an all registrants type, and the I_T nexus is the last remaining
2489 	 * registered I_T nexus, then the device server shall also release the
2490 	 * persistent reservation.
2491 	 */
2492 	if (!list_empty(&dev->t10_pr.registration_list) &&
2493 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2494 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2495 		dev->dev_pr_res_holder =
2496 			list_entry(dev->t10_pr.registration_list.next,
2497 				   struct t10_pr_registration, pr_reg_list);
2498 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2499 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2500 		dev->dev_pr_res_holder->pr_res_holder = 1;
2501 	}
2502 	spin_unlock(&dev->t10_pr.registration_lock);
2503 out:
2504 	if (!dev->dev_pr_res_holder) {
2505 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2506 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2507 			tfo->fabric_name, (explicit) ? "explicit" :
2508 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2509 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2510 	}
2511 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2512 		tfo->fabric_name, se_nacl->initiatorname,
2513 		i_buf);
2514 	/*
2515 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2516 	 */
2517 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2518 }
2519 
2520 static sense_reason_t
2521 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2522 		u64 res_key)
2523 {
2524 	struct se_device *dev = cmd->se_dev;
2525 	struct se_session *se_sess = cmd->se_sess;
2526 	struct se_lun *se_lun = cmd->se_lun;
2527 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2528 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2529 	sense_reason_t ret = 0;
2530 
2531 	if (!se_sess || !se_lun) {
2532 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2533 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2534 	}
2535 	/*
2536 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2537 	 */
2538 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2539 	if (!pr_reg) {
2540 		pr_err("SPC-3 PR: Unable to locate"
2541 			" PR_REGISTERED *pr_reg for RELEASE\n");
2542 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2543 	}
2544 	/*
2545 	 * From spc4r17 Section 5.7.11.2 Releasing:
2546 	 *
2547 	 * If there is no persistent reservation or in response to a persistent
2548 	 * reservation release request from a registered I_T nexus that is not a
2549 	 * persistent reservation holder (see 5.7.10), the device server shall
2550 	 * do the following:
2551 	 *
2552 	 *     a) Not release the persistent reservation, if any;
2553 	 *     b) Not remove any registrations; and
2554 	 *     c) Complete the command with GOOD status.
2555 	 */
2556 	spin_lock(&dev->dev_reservation_lock);
2557 	pr_res_holder = dev->dev_pr_res_holder;
2558 	if (!pr_res_holder) {
2559 		/*
2560 		 * No persistent reservation, return GOOD status.
2561 		 */
2562 		spin_unlock(&dev->dev_reservation_lock);
2563 		goto out_put_pr_reg;
2564 	}
2565 
2566 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2567 		/*
2568 		 * Release request from a registered I_T nexus that is not a
2569 		 * persistent reservation holder. return GOOD status.
2570 		 */
2571 		spin_unlock(&dev->dev_reservation_lock);
2572 		goto out_put_pr_reg;
2573 	}
2574 
2575 	/*
2576 	 * From spc4r17 Section 5.7.11.2 Releasing:
2577 	 *
2578 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2579 	 * release a persistent reservation.
2580 	 *
2581 	 * An application client releases the persistent reservation by issuing
2582 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2583 	 * an I_T nexus that is a persistent reservation holder with the
2584 	 * following parameters:
2585 	 *
2586 	 *     a) RESERVATION KEY field set to the value of the reservation key
2587 	 *	  that is registered with the logical unit for the I_T nexus;
2588 	 */
2589 	if (res_key != pr_reg->pr_res_key) {
2590 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2591 			" does not match existing SA REGISTER res_key:"
2592 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2593 		spin_unlock(&dev->dev_reservation_lock);
2594 		ret = TCM_RESERVATION_CONFLICT;
2595 		goto out_put_pr_reg;
2596 	}
2597 	/*
2598 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2599 	 *
2600 	 * b) TYPE field and SCOPE field set to match the persistent
2601 	 *    reservation being released.
2602 	 */
2603 	if ((pr_res_holder->pr_res_type != type) ||
2604 	    (pr_res_holder->pr_res_scope != scope)) {
2605 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2606 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2607 			" reservation from [%s]: %s with different TYPE "
2608 			"and/or SCOPE  while reservation already held by"
2609 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2610 			cmd->se_tfo->fabric_name,
2611 			se_sess->se_node_acl->initiatorname,
2612 			pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2613 			pr_res_holder->pr_reg_nacl->initiatorname);
2614 
2615 		spin_unlock(&dev->dev_reservation_lock);
2616 		ret = TCM_RESERVATION_CONFLICT;
2617 		goto out_put_pr_reg;
2618 	}
2619 	/*
2620 	 * In response to a persistent reservation release request from the
2621 	 * persistent reservation holder the device server shall perform a
2622 	 * release by doing the following as an uninterrupted series of actions:
2623 	 * a) Release the persistent reservation;
2624 	 * b) Not remove any registration(s);
2625 	 * c) If the released persistent reservation is a registrants only type
2626 	 * or all registrants type persistent reservation,
2627 	 *    the device server shall establish a unit attention condition for
2628 	 *    the initiator port associated with every regis-
2629 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2630 	 *    RESERVE OUT command with RELEASE service action was received,
2631 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2632 	 * d) If the persistent reservation is of any other type, the device
2633 	 *    server shall not establish a unit attention condition.
2634 	 */
2635 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2636 					  pr_reg, 1, 0);
2637 
2638 	spin_unlock(&dev->dev_reservation_lock);
2639 
2640 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2641 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2642 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2643 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2644 		/*
2645 		 * If no UNIT ATTENTION conditions will be established for
2646 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2647 		 * go ahead and check for APTPL=1 update+write below
2648 		 */
2649 		goto write_aptpl;
2650 	}
2651 
2652 	spin_lock(&pr_tmpl->registration_lock);
2653 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2654 			pr_reg_list) {
2655 		/*
2656 		 * Do not establish a UNIT ATTENTION condition
2657 		 * for the calling I_T Nexus
2658 		 */
2659 		if (pr_reg_p == pr_reg)
2660 			continue;
2661 
2662 		target_ua_allocate_lun(pr_reg_p->pr_reg_nacl,
2663 				pr_reg_p->pr_res_mapped_lun,
2664 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2665 	}
2666 	spin_unlock(&pr_tmpl->registration_lock);
2667 
2668 write_aptpl:
2669 	if (pr_tmpl->pr_aptpl_active)
2670 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2671 
2672 out_put_pr_reg:
2673 	core_scsi3_put_pr_reg(pr_reg);
2674 	return ret;
2675 }
2676 
2677 static sense_reason_t
2678 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2679 {
2680 	struct se_device *dev = cmd->se_dev;
2681 	struct se_node_acl *pr_reg_nacl;
2682 	struct se_session *se_sess = cmd->se_sess;
2683 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2684 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2685 	u64 pr_res_mapped_lun = 0;
2686 	int calling_it_nexus = 0;
2687 	/*
2688 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2689 	 */
2690 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2691 			se_sess->se_node_acl, se_sess);
2692 	if (!pr_reg_n) {
2693 		pr_err("SPC-3 PR: Unable to locate"
2694 			" PR_REGISTERED *pr_reg for CLEAR\n");
2695 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2696 	}
2697 	/*
2698 	 * From spc4r17 section 5.7.11.6, Clearing:
2699 	 *
2700 	 * Any application client may release the persistent reservation and
2701 	 * remove all registrations from a device server by issuing a
2702 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2703 	 * registered I_T nexus with the following parameter:
2704 	 *
2705 	 *	a) RESERVATION KEY field set to the value of the reservation key
2706 	 * 	   that is registered with the logical unit for the I_T nexus.
2707 	 */
2708 	if (res_key != pr_reg_n->pr_res_key) {
2709 		pr_err("SPC-3 PR REGISTER: Received"
2710 			" res_key: 0x%016Lx does not match"
2711 			" existing SA REGISTER res_key:"
2712 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2713 		core_scsi3_put_pr_reg(pr_reg_n);
2714 		return TCM_RESERVATION_CONFLICT;
2715 	}
2716 	/*
2717 	 * a) Release the persistent reservation, if any;
2718 	 */
2719 	spin_lock(&dev->dev_reservation_lock);
2720 	pr_res_holder = dev->dev_pr_res_holder;
2721 	if (pr_res_holder) {
2722 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2723 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2724 						  pr_res_holder, 0, 0);
2725 	}
2726 	spin_unlock(&dev->dev_reservation_lock);
2727 	/*
2728 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2729 	 */
2730 	spin_lock(&pr_tmpl->registration_lock);
2731 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2732 			&pr_tmpl->registration_list, pr_reg_list) {
2733 
2734 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2735 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2736 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2737 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2738 					calling_it_nexus);
2739 		/*
2740 		 * e) Establish a unit attention condition for the initiator
2741 		 *    port associated with every registered I_T nexus other
2742 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2743 		 *    command with CLEAR service action was received, with the
2744 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2745 		 */
2746 		if (!calling_it_nexus)
2747 			target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun,
2748 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2749 	}
2750 	spin_unlock(&pr_tmpl->registration_lock);
2751 
2752 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2753 		cmd->se_tfo->fabric_name);
2754 
2755 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2756 
2757 	core_scsi3_pr_generation(dev);
2758 	return 0;
2759 }
2760 
2761 static void __core_scsi3_complete_pro_preempt(
2762 	struct se_device *dev,
2763 	struct t10_pr_registration *pr_reg,
2764 	struct list_head *preempt_and_abort_list,
2765 	int type,
2766 	int scope,
2767 	enum preempt_type preempt_type)
2768 {
2769 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2770 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2771 	char i_buf[PR_REG_ISID_ID_LEN];
2772 
2773 	lockdep_assert_held(&dev->dev_reservation_lock);
2774 
2775 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2776 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2777 	/*
2778 	 * Do an implicit RELEASE of the existing reservation.
2779 	 */
2780 	if (dev->dev_pr_res_holder)
2781 		__core_scsi3_complete_pro_release(dev, nacl,
2782 						  dev->dev_pr_res_holder, 0, 0);
2783 
2784 	dev->dev_pr_res_holder = pr_reg;
2785 	pr_reg->pr_res_holder = 1;
2786 	pr_reg->pr_res_type = type;
2787 	pr_reg->pr_res_scope = scope;
2788 
2789 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2790 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2791 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2792 		core_scsi3_pr_dump_type(type),
2793 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2794 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2795 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2796 		nacl->initiatorname, i_buf);
2797 	/*
2798 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2799 	 * struct t10_pr_registration to the list that will be compared
2800 	 * against received CDBs..
2801 	 */
2802 	if (preempt_and_abort_list)
2803 		list_add_tail(&pr_reg->pr_reg_abort_list,
2804 				preempt_and_abort_list);
2805 }
2806 
2807 static void core_scsi3_release_preempt_and_abort(
2808 	struct list_head *preempt_and_abort_list,
2809 	struct t10_pr_registration *pr_reg_holder)
2810 {
2811 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2812 
2813 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2814 				pr_reg_abort_list) {
2815 
2816 		list_del(&pr_reg->pr_reg_abort_list);
2817 		if (pr_reg_holder == pr_reg)
2818 			continue;
2819 		if (pr_reg->pr_res_holder) {
2820 			pr_warn("pr_reg->pr_res_holder still set\n");
2821 			continue;
2822 		}
2823 
2824 		pr_reg->pr_reg_deve = NULL;
2825 		pr_reg->pr_reg_nacl = NULL;
2826 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2827 	}
2828 }
2829 
2830 static sense_reason_t
2831 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2832 		u64 sa_res_key, enum preempt_type preempt_type)
2833 {
2834 	struct se_device *dev = cmd->se_dev;
2835 	struct se_node_acl *pr_reg_nacl;
2836 	struct se_session *se_sess = cmd->se_sess;
2837 	LIST_HEAD(preempt_and_abort_list);
2838 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2839 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2840 	u64 pr_res_mapped_lun = 0;
2841 	int all_reg = 0, calling_it_nexus = 0;
2842 	bool sa_res_key_unmatched = sa_res_key != 0;
2843 	int prh_type = 0, prh_scope = 0;
2844 
2845 	if (!se_sess)
2846 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2847 
2848 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2849 				se_sess);
2850 	if (!pr_reg_n) {
2851 		pr_err("SPC-3 PR: Unable to locate"
2852 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2853 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2854 		return TCM_RESERVATION_CONFLICT;
2855 	}
2856 	if (pr_reg_n->pr_res_key != res_key) {
2857 		core_scsi3_put_pr_reg(pr_reg_n);
2858 		return TCM_RESERVATION_CONFLICT;
2859 	}
2860 	if (scope != PR_SCOPE_LU_SCOPE) {
2861 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2862 		core_scsi3_put_pr_reg(pr_reg_n);
2863 		return TCM_INVALID_PARAMETER_LIST;
2864 	}
2865 
2866 	spin_lock(&dev->dev_reservation_lock);
2867 	pr_res_holder = dev->dev_pr_res_holder;
2868 	if (pr_res_holder &&
2869 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2870 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2871 		all_reg = 1;
2872 
2873 	if (!all_reg && !sa_res_key) {
2874 		spin_unlock(&dev->dev_reservation_lock);
2875 		core_scsi3_put_pr_reg(pr_reg_n);
2876 		return TCM_INVALID_PARAMETER_LIST;
2877 	}
2878 	/*
2879 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2880 	 *
2881 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2882 	 * persistent reservation holder or there is no persistent reservation
2883 	 * holder (i.e., there is no persistent reservation), then the device
2884 	 * server shall perform a preempt by doing the following in an
2885 	 * uninterrupted series of actions. (See below..)
2886 	 */
2887 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2888 		/*
2889 		 * No existing or SA Reservation Key matching reservations..
2890 		 *
2891 		 * PROUT SA PREEMPT with All Registrant type reservations are
2892 		 * allowed to be processed without a matching SA Reservation Key
2893 		 */
2894 		spin_lock(&pr_tmpl->registration_lock);
2895 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2896 				&pr_tmpl->registration_list, pr_reg_list) {
2897 			/*
2898 			 * Removing of registrations in non all registrants
2899 			 * type reservations without a matching SA reservation
2900 			 * key.
2901 			 *
2902 			 * a) Remove the registrations for all I_T nexuses
2903 			 *    specified by the SERVICE ACTION RESERVATION KEY
2904 			 *    field;
2905 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2906 			 * c) Process tasks as defined in 5.7.1; and
2907 			 * d) Establish a unit attention condition for the
2908 			 *    initiator port associated with every I_T nexus
2909 			 *    that lost its registration other than the I_T
2910 			 *    nexus on which the PERSISTENT RESERVE OUT command
2911 			 *    was received, with the additional sense code set
2912 			 *    to REGISTRATIONS PREEMPTED.
2913 			 */
2914 			if (!all_reg) {
2915 				if (pr_reg->pr_res_key != sa_res_key)
2916 					continue;
2917 				sa_res_key_unmatched = false;
2918 
2919 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2920 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2921 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2922 				__core_scsi3_free_registration(dev, pr_reg,
2923 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2924 						NULL, calling_it_nexus);
2925 			} else {
2926 				/*
2927 				 * Case for any existing all registrants type
2928 				 * reservation, follow logic in spc4r17 section
2929 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2930 				 *
2931 				 * For a ZERO SA Reservation key, release
2932 				 * all other registrations and do an implicit
2933 				 * release of active persistent reservation.
2934 				 *
2935 				 * For a non-ZERO SA Reservation key, only
2936 				 * release the matching reservation key from
2937 				 * registrations.
2938 				 */
2939 				if ((sa_res_key) &&
2940 				     (pr_reg->pr_res_key != sa_res_key))
2941 					continue;
2942 				sa_res_key_unmatched = false;
2943 
2944 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2945 				if (calling_it_nexus)
2946 					continue;
2947 
2948 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2949 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2950 				__core_scsi3_free_registration(dev, pr_reg,
2951 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2952 						NULL, 0);
2953 			}
2954 			if (!calling_it_nexus)
2955 				target_ua_allocate_lun(pr_reg_nacl,
2956 					pr_res_mapped_lun, 0x2A,
2957 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2958 		}
2959 		spin_unlock(&pr_tmpl->registration_lock);
2960 		/*
2961 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2962 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2963 		 * RESERVATION KEY field to a value that does not match any
2964 		 * registered reservation key, then the device server shall
2965 		 * complete the command with RESERVATION CONFLICT status.
2966 		 */
2967 		if (sa_res_key_unmatched) {
2968 			spin_unlock(&dev->dev_reservation_lock);
2969 			core_scsi3_put_pr_reg(pr_reg_n);
2970 			return TCM_RESERVATION_CONFLICT;
2971 		}
2972 		/*
2973 		 * For an existing all registrants type reservation
2974 		 * with a zero SA rservation key, preempt the existing
2975 		 * reservation with the new PR type and scope.
2976 		 */
2977 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2978 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2979 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2980 				type, scope, preempt_type);
2981 
2982 			if (preempt_type == PREEMPT_AND_ABORT)
2983 				core_scsi3_release_preempt_and_abort(
2984 					&preempt_and_abort_list, pr_reg_n);
2985 		}
2986 		spin_unlock(&dev->dev_reservation_lock);
2987 
2988 		if (pr_tmpl->pr_aptpl_active)
2989 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2990 
2991 		core_scsi3_put_pr_reg(pr_reg_n);
2992 		core_scsi3_pr_generation(cmd->se_dev);
2993 		return 0;
2994 	}
2995 	/*
2996 	 * The PREEMPTing SA reservation key matches that of the
2997 	 * existing persistent reservation, first, we check if
2998 	 * we are preempting our own reservation.
2999 	 * From spc4r17, section 5.7.11.4.3 Preempting
3000 	 * persistent reservations and registration handling
3001 	 *
3002 	 * If an all registrants persistent reservation is not
3003 	 * present, it is not an error for the persistent
3004 	 * reservation holder to preempt itself (i.e., a
3005 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3006 	 * or a PREEMPT AND ABORT service action with the
3007 	 * SERVICE ACTION RESERVATION KEY value equal to the
3008 	 * persistent reservation holder's reservation key that
3009 	 * is received from the persistent reservation holder).
3010 	 * In that case, the device server shall establish the
3011 	 * new persistent reservation and maintain the
3012 	 * registration.
3013 	 */
3014 	prh_type = pr_res_holder->pr_res_type;
3015 	prh_scope = pr_res_holder->pr_res_scope;
3016 	/*
3017 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3018 	 * persistent reservation holder (see 5.7.10), the device
3019 	 * server shall perform a preempt by doing the following as
3020 	 * an uninterrupted series of actions:
3021 	 *
3022 	 * a) Release the persistent reservation for the holder
3023 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3024 	 */
3025 	if (pr_reg_n != pr_res_holder)
3026 		__core_scsi3_complete_pro_release(dev,
3027 						  pr_res_holder->pr_reg_nacl,
3028 						  dev->dev_pr_res_holder, 0, 0);
3029 	/*
3030 	 * b) Remove the registrations for all I_T nexuses identified
3031 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3032 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3033 	 *    OUT command. If an all registrants persistent reservation
3034 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3035 	 *    is set to zero, then all registrations shall be removed
3036 	 *    except for that of the I_T nexus that is being used for
3037 	 *    the PERSISTENT RESERVE OUT command;
3038 	 */
3039 	spin_lock(&pr_tmpl->registration_lock);
3040 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3041 			&pr_tmpl->registration_list, pr_reg_list) {
3042 
3043 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3044 		if (calling_it_nexus)
3045 			continue;
3046 
3047 		if (pr_reg->pr_res_key != sa_res_key)
3048 			continue;
3049 
3050 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3051 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3052 		__core_scsi3_free_registration(dev, pr_reg,
3053 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3054 				calling_it_nexus);
3055 		/*
3056 		 * e) Establish a unit attention condition for the initiator
3057 		 *    port associated with every I_T nexus that lost its
3058 		 *    persistent reservation and/or registration, with the
3059 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3060 		 */
3061 		target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3062 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3063 	}
3064 	spin_unlock(&pr_tmpl->registration_lock);
3065 	/*
3066 	 * c) Establish a persistent reservation for the preempting
3067 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3068 	 */
3069 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3070 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3071 			type, scope, preempt_type);
3072 	/*
3073 	 * d) Process tasks as defined in 5.7.1;
3074 	 * e) See above..
3075 	 * f) If the type or scope has changed, then for every I_T nexus
3076 	 *    whose reservation key was not removed, except for the I_T
3077 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3078 	 *    received, the device server shall establish a unit
3079 	 *    attention condition for the initiator port associated with
3080 	 *    that I_T nexus, with the additional sense code set to
3081 	 *    RESERVATIONS RELEASED. If the type or scope have not
3082 	 *    changed, then no unit attention condition(s) shall be
3083 	 *    established for this reason.
3084 	 */
3085 	if ((prh_type != type) || (prh_scope != scope)) {
3086 		spin_lock(&pr_tmpl->registration_lock);
3087 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3088 				&pr_tmpl->registration_list, pr_reg_list) {
3089 
3090 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3091 			if (calling_it_nexus)
3092 				continue;
3093 
3094 			target_ua_allocate_lun(pr_reg->pr_reg_nacl,
3095 					pr_reg->pr_res_mapped_lun, 0x2A,
3096 					ASCQ_2AH_RESERVATIONS_RELEASED);
3097 		}
3098 		spin_unlock(&pr_tmpl->registration_lock);
3099 	}
3100 	spin_unlock(&dev->dev_reservation_lock);
3101 	/*
3102 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3103 	 * All received CDBs for the matching existing reservation and
3104 	 * registrations undergo ABORT_TASK logic.
3105 	 *
3106 	 * From there, core_scsi3_release_preempt_and_abort() will
3107 	 * release every registration in the list (which have already
3108 	 * been removed from the primary pr_reg list), except the
3109 	 * new persistent reservation holder, the calling Initiator Port.
3110 	 */
3111 	if (preempt_type == PREEMPT_AND_ABORT) {
3112 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3113 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3114 						pr_reg_n);
3115 	}
3116 
3117 	if (pr_tmpl->pr_aptpl_active)
3118 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3119 
3120 	core_scsi3_put_pr_reg(pr_reg_n);
3121 	core_scsi3_pr_generation(cmd->se_dev);
3122 	return 0;
3123 }
3124 
3125 static sense_reason_t
3126 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3127 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3128 {
3129 	switch (type) {
3130 	case PR_TYPE_WRITE_EXCLUSIVE:
3131 	case PR_TYPE_EXCLUSIVE_ACCESS:
3132 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3133 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3134 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3135 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3136 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3137 					      sa_res_key, preempt_type);
3138 	default:
3139 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3140 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3141 		return TCM_INVALID_CDB_FIELD;
3142 	}
3143 }
3144 
3145 
3146 static sense_reason_t
3147 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3148 		u64 sa_res_key, int aptpl, int unreg)
3149 {
3150 	struct se_session *se_sess = cmd->se_sess;
3151 	struct se_device *dev = cmd->se_dev;
3152 	struct se_dev_entry *dest_se_deve = NULL;
3153 	struct se_lun *se_lun = cmd->se_lun, *tmp_lun;
3154 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3155 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3156 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3157 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3158 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3159 	unsigned char *buf;
3160 	const unsigned char *initiator_str;
3161 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
3162 	u32 tid_len, tmp_tid_len;
3163 	int new_reg = 0, type, scope, matching_iname;
3164 	sense_reason_t ret;
3165 	unsigned short rtpi;
3166 	unsigned char proto_ident;
3167 
3168 	if (!se_sess || !se_lun) {
3169 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3170 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3171 	}
3172 
3173 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3174 	se_tpg = se_sess->se_tpg;
3175 	tf_ops = se_tpg->se_tpg_tfo;
3176 	/*
3177 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3178 	 *	Register behaviors for a REGISTER AND MOVE service action
3179 	 *
3180 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3181 	 */
3182 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3183 				se_sess);
3184 	if (!pr_reg) {
3185 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3186 			" *pr_reg for REGISTER_AND_MOVE\n");
3187 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3188 	}
3189 	/*
3190 	 * The provided reservation key much match the existing reservation key
3191 	 * provided during this initiator's I_T nexus registration.
3192 	 */
3193 	if (res_key != pr_reg->pr_res_key) {
3194 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3195 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3196 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3197 		ret = TCM_RESERVATION_CONFLICT;
3198 		goto out_put_pr_reg;
3199 	}
3200 	/*
3201 	 * The service active reservation key needs to be non zero
3202 	 */
3203 	if (!sa_res_key) {
3204 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3205 			" sa_res_key\n");
3206 		ret = TCM_INVALID_PARAMETER_LIST;
3207 		goto out_put_pr_reg;
3208 	}
3209 
3210 	/*
3211 	 * Determine the Relative Target Port Identifier where the reservation
3212 	 * will be moved to for the TransportID containing SCSI initiator WWN
3213 	 * information.
3214 	 */
3215 	buf = transport_kmap_data_sg(cmd);
3216 	if (!buf) {
3217 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3218 		goto out_put_pr_reg;
3219 	}
3220 
3221 	rtpi = get_unaligned_be16(&buf[18]);
3222 	tid_len = get_unaligned_be32(&buf[20]);
3223 	transport_kunmap_data_sg(cmd);
3224 	buf = NULL;
3225 
3226 	if ((tid_len + 24) != cmd->data_length) {
3227 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3228 			" does not equal CDB data_length: %u\n", tid_len,
3229 			cmd->data_length);
3230 		ret = TCM_INVALID_PARAMETER_LIST;
3231 		goto out_put_pr_reg;
3232 	}
3233 
3234 	spin_lock(&dev->se_port_lock);
3235 	list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
3236 		if (tmp_lun->lun_rtpi != rtpi)
3237 			continue;
3238 		dest_se_tpg = tmp_lun->lun_tpg;
3239 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3240 		if (!dest_tf_ops)
3241 			continue;
3242 
3243 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3244 		spin_unlock(&dev->se_port_lock);
3245 
3246 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3247 			pr_err("core_scsi3_tpg_depend_item() failed"
3248 				" for dest_se_tpg\n");
3249 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3250 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3251 			goto out_put_pr_reg;
3252 		}
3253 
3254 		spin_lock(&dev->se_port_lock);
3255 		break;
3256 	}
3257 	spin_unlock(&dev->se_port_lock);
3258 
3259 	if (!dest_se_tpg || !dest_tf_ops) {
3260 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3261 			" fabric ops from Relative Target Port Identifier:"
3262 			" %hu\n", rtpi);
3263 		ret = TCM_INVALID_PARAMETER_LIST;
3264 		goto out_put_pr_reg;
3265 	}
3266 
3267 	buf = transport_kmap_data_sg(cmd);
3268 	if (!buf) {
3269 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3270 		goto out_put_pr_reg;
3271 	}
3272 	proto_ident = (buf[24] & 0x0f);
3273 
3274 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3275 			" 0x%02x\n", proto_ident);
3276 
3277 	if (proto_ident != dest_se_tpg->proto_id) {
3278 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3279 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3280 			" from fabric: %s\n", proto_ident,
3281 			dest_se_tpg->proto_id,
3282 			dest_tf_ops->fabric_name);
3283 		ret = TCM_INVALID_PARAMETER_LIST;
3284 		goto out;
3285 	}
3286 	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
3287 			&buf[24], &tmp_tid_len, &iport_ptr);
3288 	if (!initiator_str) {
3289 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3290 			" initiator_str from Transport ID\n");
3291 		ret = TCM_INVALID_PARAMETER_LIST;
3292 		goto out;
3293 	}
3294 
3295 	transport_kunmap_data_sg(cmd);
3296 	buf = NULL;
3297 
3298 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3299 		" %s\n", dest_tf_ops->fabric_name, (iport_ptr != NULL) ?
3300 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3301 		iport_ptr : "");
3302 	/*
3303 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3304 	 * action specifies a TransportID that is the same as the initiator port
3305 	 * of the I_T nexus for the command received, then the command shall
3306 	 * be terminated with CHECK CONDITION status, with the sense key set to
3307 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3308 	 * IN PARAMETER LIST.
3309 	 */
3310 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3311 	matching_iname = (!strcmp(initiator_str,
3312 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3313 	if (!matching_iname)
3314 		goto after_iport_check;
3315 
3316 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3317 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3318 			" matches: %s on received I_T Nexus\n", initiator_str,
3319 			pr_reg_nacl->initiatorname);
3320 		ret = TCM_INVALID_PARAMETER_LIST;
3321 		goto out;
3322 	}
3323 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3324 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3325 			" matches: %s %s on received I_T Nexus\n",
3326 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3327 			pr_reg->pr_reg_isid);
3328 		ret = TCM_INVALID_PARAMETER_LIST;
3329 		goto out;
3330 	}
3331 after_iport_check:
3332 	/*
3333 	 * Locate the destination struct se_node_acl from the received Transport ID
3334 	 */
3335 	mutex_lock(&dest_se_tpg->acl_node_mutex);
3336 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3337 				initiator_str);
3338 	if (dest_node_acl)
3339 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3340 	mutex_unlock(&dest_se_tpg->acl_node_mutex);
3341 
3342 	if (!dest_node_acl) {
3343 		pr_err("Unable to locate %s dest_node_acl for"
3344 			" TransportID%s\n", dest_tf_ops->fabric_name,
3345 			initiator_str);
3346 		ret = TCM_INVALID_PARAMETER_LIST;
3347 		goto out;
3348 	}
3349 
3350 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3351 		pr_err("core_scsi3_nodeacl_depend_item() for"
3352 			" dest_node_acl\n");
3353 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3354 		dest_node_acl = NULL;
3355 		ret = TCM_INVALID_PARAMETER_LIST;
3356 		goto out;
3357 	}
3358 
3359 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3360 		" %s from TransportID\n", dest_tf_ops->fabric_name,
3361 		dest_node_acl->initiatorname);
3362 
3363 	/*
3364 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3365 	 * PORT IDENTIFIER.
3366 	 */
3367 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3368 	if (!dest_se_deve) {
3369 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3370 			" %hu\n",  dest_tf_ops->fabric_name, rtpi);
3371 		ret = TCM_INVALID_PARAMETER_LIST;
3372 		goto out;
3373 	}
3374 
3375 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3376 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3377 		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
3378 		dest_se_deve = NULL;
3379 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3380 		goto out;
3381 	}
3382 
3383 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3384 		" ACL for dest_se_deve->mapped_lun: %llu\n",
3385 		dest_tf_ops->fabric_name, dest_node_acl->initiatorname,
3386 		dest_se_deve->mapped_lun);
3387 
3388 	/*
3389 	 * A persistent reservation needs to already existing in order to
3390 	 * successfully complete the REGISTER_AND_MOVE service action..
3391 	 */
3392 	spin_lock(&dev->dev_reservation_lock);
3393 	pr_res_holder = dev->dev_pr_res_holder;
3394 	if (!pr_res_holder) {
3395 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3396 			" currently held\n");
3397 		spin_unlock(&dev->dev_reservation_lock);
3398 		ret = TCM_INVALID_CDB_FIELD;
3399 		goto out;
3400 	}
3401 	/*
3402 	 * The received on I_T Nexus must be the reservation holder.
3403 	 *
3404 	 * From spc4r17 section 5.7.8  Table 50 --
3405 	 * 	Register behaviors for a REGISTER AND MOVE service action
3406 	 */
3407 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3408 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3409 			" Nexus is not reservation holder\n");
3410 		spin_unlock(&dev->dev_reservation_lock);
3411 		ret = TCM_RESERVATION_CONFLICT;
3412 		goto out;
3413 	}
3414 	/*
3415 	 * From spc4r17 section 5.7.8: registering and moving reservation
3416 	 *
3417 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3418 	 * action is received and the established persistent reservation is a
3419 	 * Write Exclusive - All Registrants type or Exclusive Access -
3420 	 * All Registrants type reservation, then the command shall be completed
3421 	 * with RESERVATION CONFLICT status.
3422 	 */
3423 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3424 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3425 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3426 			" reservation for type: %s\n",
3427 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3428 		spin_unlock(&dev->dev_reservation_lock);
3429 		ret = TCM_RESERVATION_CONFLICT;
3430 		goto out;
3431 	}
3432 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3433 	/*
3434 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3435 	 */
3436 	type = pr_res_holder->pr_res_type;
3437 	scope = pr_res_holder->pr_res_type;
3438 	/*
3439 	 * c) Associate the reservation key specified in the SERVICE ACTION
3440 	 *    RESERVATION KEY field with the I_T nexus specified as the
3441 	 *    destination of the register and move, where:
3442 	 *    A) The I_T nexus is specified by the TransportID and the
3443 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3444 	 *    B) Regardless of the TransportID format used, the association for
3445 	 *       the initiator port is based on either the initiator port name
3446 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3447 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3448 	 *       transport protocols where port names are not required;
3449 	 * d) Register the reservation key specified in the SERVICE ACTION
3450 	 *    RESERVATION KEY field;
3451 	 * e) Retain the reservation key specified in the SERVICE ACTION
3452 	 *    RESERVATION KEY field and associated information;
3453 	 *
3454 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3455 	 * register an I_T nexus that is already registered with the same
3456 	 * reservation key or a different reservation key.
3457 	 */
3458 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3459 					iport_ptr);
3460 	if (!dest_pr_reg) {
3461 		struct se_lun *dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
3462 				kref_read(&dest_se_deve->pr_kref) != 0);
3463 
3464 		spin_unlock(&dev->dev_reservation_lock);
3465 		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
3466 					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
3467 					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
3468 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3469 			goto out;
3470 		}
3471 		spin_lock(&dev->dev_reservation_lock);
3472 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3473 						iport_ptr);
3474 		new_reg = 1;
3475 	}
3476 	/*
3477 	 * f) Release the persistent reservation for the persistent reservation
3478 	 *    holder (i.e., the I_T nexus on which the
3479 	 */
3480 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3481 					  dev->dev_pr_res_holder, 0, 0);
3482 	/*
3483 	 * g) Move the persistent reservation to the specified I_T nexus using
3484 	 *    the same scope and type as the persistent reservation released in
3485 	 *    item f); and
3486 	 */
3487 	dev->dev_pr_res_holder = dest_pr_reg;
3488 	dest_pr_reg->pr_res_holder = 1;
3489 	dest_pr_reg->pr_res_type = type;
3490 	pr_reg->pr_res_scope = scope;
3491 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3492 	/*
3493 	 * Increment PRGeneration for existing registrations..
3494 	 */
3495 	if (!new_reg)
3496 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3497 	spin_unlock(&dev->dev_reservation_lock);
3498 
3499 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3500 		" created new reservation holder TYPE: %s on object RTPI:"
3501 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->fabric_name,
3502 		core_scsi3_pr_dump_type(type), rtpi,
3503 		dest_pr_reg->pr_res_generation);
3504 	pr_debug("SPC-3 PR Successfully moved reservation from"
3505 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3506 		tf_ops->fabric_name, pr_reg_nacl->initiatorname,
3507 		i_buf, dest_tf_ops->fabric_name,
3508 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3509 		iport_ptr : "");
3510 	/*
3511 	 * It is now safe to release configfs group dependencies for destination
3512 	 * of Transport ID Initiator Device/Port Identifier
3513 	 */
3514 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3515 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3516 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3517 	/*
3518 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3519 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3520 	 */
3521 	if (unreg) {
3522 		spin_lock(&pr_tmpl->registration_lock);
3523 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3524 		spin_unlock(&pr_tmpl->registration_lock);
3525 	} else
3526 		core_scsi3_put_pr_reg(pr_reg);
3527 
3528 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3529 
3530 	core_scsi3_put_pr_reg(dest_pr_reg);
3531 	return 0;
3532 out:
3533 	if (buf)
3534 		transport_kunmap_data_sg(cmd);
3535 	if (dest_se_deve)
3536 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3537 	if (dest_node_acl)
3538 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3539 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3540 
3541 out_put_pr_reg:
3542 	core_scsi3_put_pr_reg(pr_reg);
3543 	return ret;
3544 }
3545 
3546 /*
3547  * See spc4r17 section 6.14 Table 170
3548  */
3549 sense_reason_t
3550 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3551 {
3552 	struct se_device *dev = cmd->se_dev;
3553 	unsigned char *cdb = &cmd->t_task_cdb[0];
3554 	unsigned char *buf;
3555 	u64 res_key, sa_res_key;
3556 	int sa, scope, type, aptpl;
3557 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3558 	sense_reason_t ret;
3559 
3560 	/*
3561 	 * Following spc2r20 5.5.1 Reservations overview:
3562 	 *
3563 	 * If a logical unit has been reserved by any RESERVE command and is
3564 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3565 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3566 	 * initiator or service action and shall terminate with a RESERVATION
3567 	 * CONFLICT status.
3568 	 */
3569 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3570 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3571 			" SPC-2 reservation is held, returning"
3572 			" RESERVATION_CONFLICT\n");
3573 		return TCM_RESERVATION_CONFLICT;
3574 	}
3575 
3576 	/*
3577 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3578 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3579 	 */
3580 	if (!cmd->se_sess)
3581 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3582 
3583 	if (cmd->data_length < 24) {
3584 		pr_warn("SPC-PR: Received PR OUT parameter list"
3585 			" length too small: %u\n", cmd->data_length);
3586 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3587 	}
3588 
3589 	/*
3590 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3591 	 */
3592 	sa = (cdb[1] & 0x1f);
3593 	scope = (cdb[2] & 0xf0);
3594 	type = (cdb[2] & 0x0f);
3595 
3596 	buf = transport_kmap_data_sg(cmd);
3597 	if (!buf)
3598 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3599 
3600 	/*
3601 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3602 	 */
3603 	res_key = get_unaligned_be64(&buf[0]);
3604 	sa_res_key = get_unaligned_be64(&buf[8]);
3605 	/*
3606 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3607 	 * SCSI TransportIDs.
3608 	 */
3609 	if (sa != PRO_REGISTER_AND_MOVE) {
3610 		spec_i_pt = (buf[20] & 0x08);
3611 		all_tg_pt = (buf[20] & 0x04);
3612 		aptpl = (buf[20] & 0x01);
3613 	} else {
3614 		aptpl = (buf[17] & 0x01);
3615 		unreg = (buf[17] & 0x02);
3616 	}
3617 	/*
3618 	 * If the backend device has been configured to force APTPL metadata
3619 	 * write-out, go ahead and propigate aptpl=1 down now.
3620 	 */
3621 	if (dev->dev_attrib.force_pr_aptpl)
3622 		aptpl = 1;
3623 
3624 	transport_kunmap_data_sg(cmd);
3625 	buf = NULL;
3626 
3627 	/*
3628 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3629 	 */
3630 	if (spec_i_pt && (sa != PRO_REGISTER))
3631 		return TCM_INVALID_PARAMETER_LIST;
3632 
3633 	/*
3634 	 * From spc4r17 section 6.14:
3635 	 *
3636 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3637 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3638 	 * the command shall be terminated with CHECK CONDITION status, with
3639 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3640 	 * code set to PARAMETER LIST LENGTH ERROR.
3641 	 */
3642 	if (!spec_i_pt && (sa != PRO_REGISTER_AND_MOVE) &&
3643 	    (cmd->data_length != 24)) {
3644 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3645 			" list length: %u\n", cmd->data_length);
3646 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3647 	}
3648 
3649 	/*
3650 	 * (core_scsi3_emulate_pro_* function parameters
3651 	 * are defined by spc4r17 Table 174:
3652 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3653 	 */
3654 	switch (sa) {
3655 	case PRO_REGISTER:
3656 		ret = core_scsi3_emulate_pro_register(cmd,
3657 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3658 		break;
3659 	case PRO_RESERVE:
3660 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3661 		break;
3662 	case PRO_RELEASE:
3663 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3664 		break;
3665 	case PRO_CLEAR:
3666 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3667 		break;
3668 	case PRO_PREEMPT:
3669 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3670 					res_key, sa_res_key, PREEMPT);
3671 		break;
3672 	case PRO_PREEMPT_AND_ABORT:
3673 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3674 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3675 		break;
3676 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3677 		ret = core_scsi3_emulate_pro_register(cmd,
3678 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3679 		break;
3680 	case PRO_REGISTER_AND_MOVE:
3681 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3682 				sa_res_key, aptpl, unreg);
3683 		break;
3684 	default:
3685 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3686 			" action: 0x%02x\n", sa);
3687 		return TCM_INVALID_CDB_FIELD;
3688 	}
3689 
3690 	if (!ret)
3691 		target_complete_cmd(cmd, GOOD);
3692 	return ret;
3693 }
3694 
3695 /*
3696  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3697  *
3698  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3699  */
3700 static sense_reason_t
3701 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3702 {
3703 	struct se_device *dev = cmd->se_dev;
3704 	struct t10_pr_registration *pr_reg;
3705 	unsigned char *buf;
3706 	u32 add_len = 0, off = 8;
3707 
3708 	if (cmd->data_length < 8) {
3709 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3710 			" too small\n", cmd->data_length);
3711 		return TCM_INVALID_CDB_FIELD;
3712 	}
3713 
3714 	buf = transport_kmap_data_sg(cmd);
3715 	if (!buf)
3716 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3717 
3718 	put_unaligned_be32(dev->t10_pr.pr_generation, buf);
3719 
3720 	spin_lock(&dev->t10_pr.registration_lock);
3721 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3722 			pr_reg_list) {
3723 		/*
3724 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3725 		 * next reservation key list descriptor.
3726 		 */
3727 		if (off + 8 <= cmd->data_length) {
3728 			put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3729 			off += 8;
3730 		}
3731 		/*
3732 		 * SPC5r17: 6.16.2 READ KEYS service action
3733 		 * The ADDITIONAL LENGTH field indicates the number of bytes in
3734 		 * the Reservation key list. The contents of the ADDITIONAL
3735 		 * LENGTH field are not altered based on the allocation length
3736 		 */
3737 		add_len += 8;
3738 	}
3739 	spin_unlock(&dev->t10_pr.registration_lock);
3740 
3741 	put_unaligned_be32(add_len, &buf[4]);
3742 
3743 	transport_kunmap_data_sg(cmd);
3744 
3745 	return 0;
3746 }
3747 
3748 /*
3749  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3750  *
3751  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3752  */
3753 static sense_reason_t
3754 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3755 {
3756 	struct se_device *dev = cmd->se_dev;
3757 	struct t10_pr_registration *pr_reg;
3758 	unsigned char *buf;
3759 	u64 pr_res_key;
3760 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3761 
3762 	if (cmd->data_length < 8) {
3763 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3764 			" too small\n", cmd->data_length);
3765 		return TCM_INVALID_CDB_FIELD;
3766 	}
3767 
3768 	buf = transport_kmap_data_sg(cmd);
3769 	if (!buf)
3770 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3771 
3772 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3773 
3774 	spin_lock(&dev->dev_reservation_lock);
3775 	pr_reg = dev->dev_pr_res_holder;
3776 	if (pr_reg) {
3777 		/*
3778 		 * Set the hardcoded Additional Length
3779 		 */
3780 		put_unaligned_be32(add_len, &buf[4]);
3781 
3782 		if (cmd->data_length < 22)
3783 			goto err;
3784 
3785 		/*
3786 		 * Set the Reservation key.
3787 		 *
3788 		 * From spc4r17, section 5.7.10:
3789 		 * A persistent reservation holder has its reservation key
3790 		 * returned in the parameter data from a PERSISTENT
3791 		 * RESERVE IN command with READ RESERVATION service action as
3792 		 * follows:
3793 		 * a) For a persistent reservation of the type Write Exclusive
3794 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3795 		 *      the reservation key shall be set to zero; or
3796 		 * b) For all other persistent reservation types, the
3797 		 *    reservation key shall be set to the registered
3798 		 *    reservation key for the I_T nexus that holds the
3799 		 *    persistent reservation.
3800 		 */
3801 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3802 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3803 			pr_res_key = 0;
3804 		else
3805 			pr_res_key = pr_reg->pr_res_key;
3806 
3807 		put_unaligned_be64(pr_res_key, &buf[8]);
3808 		/*
3809 		 * Set the SCOPE and TYPE
3810 		 */
3811 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3812 			  (pr_reg->pr_res_type & 0x0f);
3813 	}
3814 
3815 err:
3816 	spin_unlock(&dev->dev_reservation_lock);
3817 	transport_kunmap_data_sg(cmd);
3818 
3819 	return 0;
3820 }
3821 
3822 /*
3823  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3824  *
3825  * See spc4r17 section 6.13.4 Table 165
3826  */
3827 static sense_reason_t
3828 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3829 {
3830 	struct se_device *dev = cmd->se_dev;
3831 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3832 	unsigned char *buf;
3833 	u16 add_len = 8; /* Hardcoded to 8. */
3834 
3835 	if (cmd->data_length < 6) {
3836 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3837 			" %u too small\n", cmd->data_length);
3838 		return TCM_INVALID_CDB_FIELD;
3839 	}
3840 
3841 	buf = transport_kmap_data_sg(cmd);
3842 	if (!buf)
3843 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3844 
3845 	put_unaligned_be16(add_len, &buf[0]);
3846 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3847 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3848 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3849 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3850 	/*
3851 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3852 	 * set the TMV: Task Mask Valid bit.
3853 	 */
3854 	buf[3] |= 0x80;
3855 	/*
3856 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3857 	 */
3858 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3859 	/*
3860 	 * PTPL_A: Persistence across Target Power Loss Active bit
3861 	 */
3862 	if (pr_tmpl->pr_aptpl_active)
3863 		buf[3] |= 0x01;
3864 	/*
3865 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3866 	 */
3867 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3868 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3869 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3870 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3871 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3872 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3873 
3874 	transport_kunmap_data_sg(cmd);
3875 
3876 	return 0;
3877 }
3878 
3879 /*
3880  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3881  *
3882  * See spc4r17 section 6.13.5 Table 168 and 169
3883  */
3884 static sense_reason_t
3885 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3886 {
3887 	struct se_device *dev = cmd->se_dev;
3888 	struct se_node_acl *se_nacl;
3889 	struct se_portal_group *se_tpg;
3890 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3891 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3892 	unsigned char *buf;
3893 	u32 add_desc_len = 0, add_len = 0;
3894 	u32 off = 8; /* off into first Full Status descriptor */
3895 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3896 	int exp_desc_len, desc_len;
3897 	bool all_reg = false;
3898 
3899 	if (cmd->data_length < 8) {
3900 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3901 			" too small\n", cmd->data_length);
3902 		return TCM_INVALID_CDB_FIELD;
3903 	}
3904 
3905 	buf = transport_kmap_data_sg(cmd);
3906 	if (!buf)
3907 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3908 
3909 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3910 
3911 	spin_lock(&dev->dev_reservation_lock);
3912 	if (dev->dev_pr_res_holder) {
3913 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3914 
3915 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3916 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3917 			all_reg = true;
3918 			pr_res_type = pr_holder->pr_res_type;
3919 			pr_res_scope = pr_holder->pr_res_scope;
3920 		}
3921 	}
3922 	spin_unlock(&dev->dev_reservation_lock);
3923 
3924 	spin_lock(&pr_tmpl->registration_lock);
3925 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3926 			&pr_tmpl->registration_list, pr_reg_list) {
3927 
3928 		se_nacl = pr_reg->pr_reg_nacl;
3929 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3930 		add_desc_len = 0;
3931 
3932 		atomic_inc_mb(&pr_reg->pr_res_holders);
3933 		spin_unlock(&pr_tmpl->registration_lock);
3934 		/*
3935 		 * Determine expected length of $FABRIC_MOD specific
3936 		 * TransportID full status descriptor..
3937 		 */
3938 		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
3939 					&format_code);
3940 		if (exp_desc_len < 0 ||
3941 		    exp_desc_len + add_len > cmd->data_length) {
3942 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3943 				" out of buffer: %d\n", cmd->data_length);
3944 			spin_lock(&pr_tmpl->registration_lock);
3945 			atomic_dec_mb(&pr_reg->pr_res_holders);
3946 			break;
3947 		}
3948 		/*
3949 		 * Set RESERVATION KEY
3950 		 */
3951 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3952 		off += 8;
3953 		off += 4; /* Skip Over Reserved area */
3954 
3955 		/*
3956 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3957 		 */
3958 		if (pr_reg->pr_reg_all_tg_pt)
3959 			buf[off] = 0x02;
3960 		/*
3961 		 * The struct se_lun pointer will be present for the
3962 		 * reservation holder for PR_HOLDER bit.
3963 		 *
3964 		 * Also, if this registration is the reservation
3965 		 * holder or there is an All Registrants reservation
3966 		 * active, fill in SCOPE and TYPE in the next byte.
3967 		 */
3968 		if (pr_reg->pr_res_holder) {
3969 			buf[off++] |= 0x01;
3970 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3971 				     (pr_reg->pr_res_type & 0x0f);
3972 		} else if (all_reg) {
3973 			buf[off++] |= 0x01;
3974 			buf[off++] = (pr_res_scope & 0xf0) |
3975 				     (pr_res_type & 0x0f);
3976 		} else {
3977 			off += 2;
3978 		}
3979 
3980 		off += 4; /* Skip over reserved area */
3981 		/*
3982 		 * From spc4r17 6.3.15:
3983 		 *
3984 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
3985 		 * IDENTIFIER field contains the relative port identifier (see
3986 		 * 3.1.120) of the target port that is part of the I_T nexus
3987 		 * described by this full status descriptor. If the ALL_TG_PT
3988 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
3989 		 * IDENTIFIER field are not defined by this standard.
3990 		 */
3991 		if (!pr_reg->pr_reg_all_tg_pt) {
3992 			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;
3993 
3994 			put_unaligned_be16(sep_rtpi, &buf[off]);
3995 			off += 2;
3996 		} else
3997 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
3998 
3999 		buf[off+4] = se_tpg->proto_id;
4000 
4001 		/*
4002 		 * Now, have the $FABRIC_MOD fill in the transport ID.
4003 		 */
4004 		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
4005 				&format_code, &buf[off+4]);
4006 
4007 		spin_lock(&pr_tmpl->registration_lock);
4008 		atomic_dec_mb(&pr_reg->pr_res_holders);
4009 
4010 		if (desc_len < 0)
4011 			break;
4012 		/*
4013 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4014 		 */
4015 		put_unaligned_be32(desc_len, &buf[off]);
4016 		off += 4;
4017 		/*
4018 		 * Size of full desctipor header minus TransportID
4019 		 * containing $FABRIC_MOD specific) initiator device/port
4020 		 * WWN information.
4021 		 *
4022 		 *  See spc4r17 Section 6.13.5 Table 169
4023 		 */
4024 		add_desc_len = (24 + desc_len);
4025 
4026 		off += desc_len;
4027 		add_len += add_desc_len;
4028 	}
4029 	spin_unlock(&pr_tmpl->registration_lock);
4030 	/*
4031 	 * Set ADDITIONAL_LENGTH
4032 	 */
4033 	put_unaligned_be32(add_len, &buf[4]);
4034 
4035 	transport_kunmap_data_sg(cmd);
4036 
4037 	return 0;
4038 }
4039 
4040 sense_reason_t
4041 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4042 {
4043 	sense_reason_t ret;
4044 
4045 	/*
4046 	 * Following spc2r20 5.5.1 Reservations overview:
4047 	 *
4048 	 * If a logical unit has been reserved by any RESERVE command and is
4049 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4050 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4051 	 * initiator or service action and shall terminate with a RESERVATION
4052 	 * CONFLICT status.
4053 	 */
4054 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4055 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4056 			" SPC-2 reservation is held, returning"
4057 			" RESERVATION_CONFLICT\n");
4058 		return TCM_RESERVATION_CONFLICT;
4059 	}
4060 
4061 	switch (cmd->t_task_cdb[1] & 0x1f) {
4062 	case PRI_READ_KEYS:
4063 		ret = core_scsi3_pri_read_keys(cmd);
4064 		break;
4065 	case PRI_READ_RESERVATION:
4066 		ret = core_scsi3_pri_read_reservation(cmd);
4067 		break;
4068 	case PRI_REPORT_CAPABILITIES:
4069 		ret = core_scsi3_pri_report_capabilities(cmd);
4070 		break;
4071 	case PRI_READ_FULL_STATUS:
4072 		ret = core_scsi3_pri_read_full_status(cmd);
4073 		break;
4074 	default:
4075 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4076 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4077 		return TCM_INVALID_CDB_FIELD;
4078 	}
4079 
4080 	if (!ret)
4081 		target_complete_cmd(cmd, GOOD);
4082 	return ret;
4083 }
4084 
4085 sense_reason_t
4086 target_check_reservation(struct se_cmd *cmd)
4087 {
4088 	struct se_device *dev = cmd->se_dev;
4089 	sense_reason_t ret;
4090 
4091 	if (!cmd->se_sess)
4092 		return 0;
4093 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4094 		return 0;
4095 	if (!dev->dev_attrib.emulate_pr)
4096 		return 0;
4097 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
4098 		return 0;
4099 
4100 	spin_lock(&dev->dev_reservation_lock);
4101 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4102 		ret = target_scsi2_reservation_check(cmd);
4103 	else
4104 		ret = target_scsi3_pr_reservation_check(cmd);
4105 	spin_unlock(&dev->dev_reservation_lock);
4106 
4107 	return ret;
4108 }
4109