xref: /linux/drivers/target/target_core_pr.c (revision 906fd46a65383cd639e5eec72a047efc33045d86)
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, SAM_STAT_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 CONFLICT 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, SAM_STAT_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 READ_CAPACITY:
474 	case REPORT_LUNS:
475 	case REQUEST_SENSE:
476 	case PERSISTENT_RESERVE_IN:
477 		ret = 0; /*/ Allowed CDBs */
478 		break;
479 	default:
480 		other_cdb = 1;
481 		break;
482 	}
483 	/*
484 	 * Case where the CDB is explicitly allowed in the above switch
485 	 * statement.
486 	 */
487 	if (!ret && !other_cdb) {
488 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
489 			" reservation holder\n", cdb[0],
490 			core_scsi3_pr_dump_type(pr_reg_type));
491 
492 		return ret;
493 	}
494 	/*
495 	 * Check if write exclusive initiator ports *NOT* holding the
496 	 * WRITE_EXCLUSIVE_* reservation.
497 	 */
498 	if (we && !registered_nexus) {
499 		if (cmd->data_direction == DMA_TO_DEVICE) {
500 			/*
501 			 * Conflict for write exclusive
502 			 */
503 			pr_debug("%s Conflict for unregistered nexus"
504 				" %s CDB: 0x%02x to %s reservation\n",
505 				transport_dump_cmd_direction(cmd),
506 				se_sess->se_node_acl->initiatorname, cdb[0],
507 				core_scsi3_pr_dump_type(pr_reg_type));
508 			return 1;
509 		} else {
510 			/*
511 			 * Allow non WRITE CDBs for all Write Exclusive
512 			 * PR TYPEs to pass for registered and
513 			 * non-registered_nexuxes NOT holding the reservation.
514 			 *
515 			 * We only make noise for the unregisterd nexuses,
516 			 * as we expect registered non-reservation holding
517 			 * nexuses to issue CDBs.
518 			 */
519 
520 			if (!registered_nexus) {
521 				pr_debug("Allowing implicit CDB: 0x%02x"
522 					" for %s reservation on unregistered"
523 					" nexus\n", cdb[0],
524 					core_scsi3_pr_dump_type(pr_reg_type));
525 			}
526 
527 			return 0;
528 		}
529 	} else if ((reg_only) || (all_reg)) {
530 		if (registered_nexus) {
531 			/*
532 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
533 			 * allow commands from registered nexuses.
534 			 */
535 
536 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
537 				" reservation\n", cdb[0],
538 				core_scsi3_pr_dump_type(pr_reg_type));
539 
540 			return 0;
541 		}
542        } else if (we && registered_nexus) {
543                /*
544                 * Reads are allowed for Write Exclusive locks
545                 * from all registrants.
546                 */
547                if (cmd->data_direction == DMA_FROM_DEVICE) {
548                        pr_debug("Allowing READ CDB: 0x%02x for %s"
549                                " reservation\n", cdb[0],
550                                core_scsi3_pr_dump_type(pr_reg_type));
551 
552                        return 0;
553                }
554 	}
555 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
556 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
557 		(registered_nexus) ? "" : "un",
558 		se_sess->se_node_acl->initiatorname, cdb[0],
559 		core_scsi3_pr_dump_type(pr_reg_type));
560 
561 	return 1; /* Conflict by default */
562 }
563 
564 static sense_reason_t
565 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
566 {
567 	struct se_device *dev = cmd->se_dev;
568 	struct se_session *sess = cmd->se_sess;
569 	u32 pr_reg_type;
570 	bool isid_mismatch = false;
571 
572 	if (!dev->dev_pr_res_holder)
573 		return 0;
574 
575 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
576 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
577 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
578 		goto check_nonholder;
579 
580 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
581 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
582 		    sess->sess_bin_isid) {
583 			isid_mismatch = true;
584 			goto check_nonholder;
585 		}
586 	}
587 
588 	return 0;
589 
590 check_nonholder:
591 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type, isid_mismatch))
592 		return TCM_RESERVATION_CONFLICT;
593 	return 0;
594 }
595 
596 static u32 core_scsi3_pr_generation(struct se_device *dev)
597 {
598 	u32 prg;
599 
600 	/*
601 	 * PRGeneration field shall contain the value of a 32-bit wrapping
602 	 * counter mainted by the device server.
603 	 *
604 	 * Note that this is done regardless of Active Persist across
605 	 * Target PowerLoss (APTPL)
606 	 *
607 	 * See spc4r17 section 6.3.12 READ_KEYS service action
608 	 */
609 	spin_lock(&dev->dev_reservation_lock);
610 	prg = dev->t10_pr.pr_generation++;
611 	spin_unlock(&dev->dev_reservation_lock);
612 
613 	return prg;
614 }
615 
616 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
617 	struct se_device *dev,
618 	struct se_node_acl *nacl,
619 	struct se_lun *lun,
620 	struct se_dev_entry *dest_deve,
621 	u64 mapped_lun,
622 	unsigned char *isid,
623 	u64 sa_res_key,
624 	int all_tg_pt,
625 	int aptpl)
626 {
627 	struct t10_pr_registration *pr_reg;
628 
629 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
630 	if (!pr_reg) {
631 		pr_err("Unable to allocate struct t10_pr_registration\n");
632 		return NULL;
633 	}
634 
635 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
636 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
637 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
638 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
639 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
640 	atomic_set(&pr_reg->pr_res_holders, 0);
641 	pr_reg->pr_reg_nacl = nacl;
642 	/*
643 	 * For destination registrations for ALL_TG_PT=1 and SPEC_I_PT=1,
644 	 * the se_dev_entry->pr_ref will have been already obtained by
645 	 * core_get_se_deve_from_rtpi() or __core_scsi3_alloc_registration().
646 	 *
647 	 * Otherwise, locate se_dev_entry now and obtain a reference until
648 	 * registration completes in __core_scsi3_add_registration().
649 	 */
650 	if (dest_deve) {
651 		pr_reg->pr_reg_deve = dest_deve;
652 	} else {
653 		rcu_read_lock();
654 		pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
655 		if (!pr_reg->pr_reg_deve) {
656 			rcu_read_unlock();
657 			pr_err("Unable to locate PR deve %s mapped_lun: %llu\n",
658 				nacl->initiatorname, mapped_lun);
659 			kmem_cache_free(t10_pr_reg_cache, pr_reg);
660 			return NULL;
661 		}
662 		kref_get(&pr_reg->pr_reg_deve->pr_kref);
663 		rcu_read_unlock();
664 	}
665 	pr_reg->pr_res_mapped_lun = mapped_lun;
666 	pr_reg->pr_aptpl_target_lun = lun->unpacked_lun;
667 	pr_reg->tg_pt_sep_rtpi = lun->lun_tpg->tpg_rtpi;
668 	pr_reg->pr_res_key = sa_res_key;
669 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
670 	pr_reg->pr_reg_aptpl = aptpl;
671 	/*
672 	 * If an ISID value for this SCSI Initiator Port exists,
673 	 * save it to the registration now.
674 	 */
675 	if (isid != NULL) {
676 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
677 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
678 		pr_reg->isid_present_at_reg = 1;
679 	}
680 
681 	return pr_reg;
682 }
683 
684 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
685 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
686 
687 /*
688  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
689  * modes.
690  */
691 static struct t10_pr_registration *__core_scsi3_alloc_registration(
692 	struct se_device *dev,
693 	struct se_node_acl *nacl,
694 	struct se_lun *lun,
695 	struct se_dev_entry *deve,
696 	u64 mapped_lun,
697 	unsigned char *isid,
698 	u64 sa_res_key,
699 	int all_tg_pt,
700 	int aptpl)
701 {
702 	struct se_dev_entry *deve_tmp;
703 	struct se_node_acl *nacl_tmp;
704 	struct se_lun_acl *lacl_tmp;
705 	struct se_lun *lun_tmp, *next, *dest_lun;
706 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
707 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
708 	int ret;
709 	/*
710 	 * Create a registration for the I_T Nexus upon which the
711 	 * PROUT REGISTER was received.
712 	 */
713 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, lun, deve, mapped_lun,
714 						    isid, sa_res_key, all_tg_pt,
715 						    aptpl);
716 	if (!pr_reg)
717 		return NULL;
718 	/*
719 	 * Return pointer to pr_reg for ALL_TG_PT=0
720 	 */
721 	if (!all_tg_pt)
722 		return pr_reg;
723 	/*
724 	 * Create list of matching SCSI Initiator Port registrations
725 	 * for ALL_TG_PT=1
726 	 */
727 	spin_lock(&dev->se_port_lock);
728 	list_for_each_entry_safe(lun_tmp, next, &dev->dev_sep_list, lun_dev_link) {
729 		if (!percpu_ref_tryget_live(&lun_tmp->lun_ref))
730 			continue;
731 		spin_unlock(&dev->se_port_lock);
732 
733 		spin_lock(&lun_tmp->lun_deve_lock);
734 		list_for_each_entry(deve_tmp, &lun_tmp->lun_deve_list, lun_link) {
735 			/*
736 			 * This pointer will be NULL for demo mode MappedLUNs
737 			 * that have not been make explicit via a ConfigFS
738 			 * MappedLUN group for the SCSI Initiator Node ACL.
739 			 */
740 			if (!deve_tmp->se_lun_acl)
741 				continue;
742 
743 			lacl_tmp = deve_tmp->se_lun_acl;
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 = deve_tmp->se_lun;
788 
789 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
790 						nacl_tmp, dest_lun, deve_tmp,
791 						deve_tmp->mapped_lun, NULL,
792 						sa_res_key, all_tg_pt, aptpl);
793 			if (!pr_reg_atp) {
794 				percpu_ref_put(&lun_tmp->lun_ref);
795 				core_scsi3_lunacl_undepend_item(deve_tmp);
796 				goto out;
797 			}
798 
799 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
800 				      &pr_reg->pr_reg_atp_list);
801 			spin_lock(&lun_tmp->lun_deve_lock);
802 		}
803 		spin_unlock(&lun_tmp->lun_deve_lock);
804 
805 		spin_lock(&dev->se_port_lock);
806 		percpu_ref_put(&lun_tmp->lun_ref);
807 	}
808 	spin_unlock(&dev->se_port_lock);
809 
810 	return pr_reg;
811 out:
812 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
813 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
814 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
815 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
816 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
817 	}
818 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
819 	return NULL;
820 }
821 
822 int core_scsi3_alloc_aptpl_registration(
823 	struct t10_reservation *pr_tmpl,
824 	u64 sa_res_key,
825 	unsigned char *i_port,
826 	unsigned char *isid,
827 	u64 mapped_lun,
828 	unsigned char *t_port,
829 	u16 tpgt,
830 	u64 target_lun,
831 	int res_holder,
832 	int all_tg_pt,
833 	u8 type)
834 {
835 	struct t10_pr_registration *pr_reg;
836 
837 	if (!i_port || !t_port || !sa_res_key) {
838 		pr_err("Illegal parameters for APTPL registration\n");
839 		return -EINVAL;
840 	}
841 
842 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
843 	if (!pr_reg) {
844 		pr_err("Unable to allocate struct t10_pr_registration\n");
845 		return -ENOMEM;
846 	}
847 
848 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
849 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
850 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
851 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
852 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
853 	atomic_set(&pr_reg->pr_res_holders, 0);
854 	pr_reg->pr_reg_nacl = NULL;
855 	pr_reg->pr_reg_deve = NULL;
856 	pr_reg->pr_res_mapped_lun = mapped_lun;
857 	pr_reg->pr_aptpl_target_lun = target_lun;
858 	pr_reg->pr_res_key = sa_res_key;
859 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
860 	pr_reg->pr_reg_aptpl = 1;
861 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
862 	pr_reg->pr_res_type = type;
863 	/*
864 	 * If an ISID value had been saved in APTPL metadata for this
865 	 * SCSI Initiator Port, restore it now.
866 	 */
867 	if (isid != NULL) {
868 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
869 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
870 		pr_reg->isid_present_at_reg = 1;
871 	}
872 	/*
873 	 * Copy the i_port and t_port information from caller.
874 	 */
875 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
876 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
877 	pr_reg->pr_reg_tpgt = tpgt;
878 	/*
879 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
880 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
881 	 * the Initiator Node LUN ACL from the fabric module is created for
882 	 * this registration.
883 	 */
884 	pr_reg->pr_res_holder = res_holder;
885 
886 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
887 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
888 			" metadata\n", (res_holder) ? "+reservation" : "");
889 	return 0;
890 }
891 
892 static void core_scsi3_aptpl_reserve(
893 	struct se_device *dev,
894 	struct se_portal_group *tpg,
895 	struct se_node_acl *node_acl,
896 	struct t10_pr_registration *pr_reg)
897 {
898 	char i_buf[PR_REG_ISID_ID_LEN] = { };
899 
900 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
901 
902 	spin_lock(&dev->dev_reservation_lock);
903 	dev->dev_pr_res_holder = pr_reg;
904 	spin_unlock(&dev->dev_reservation_lock);
905 
906 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
907 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
908 		tpg->se_tpg_tfo->fabric_name,
909 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
910 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
911 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
912 		tpg->se_tpg_tfo->fabric_name, node_acl->initiatorname,
913 		i_buf);
914 }
915 
916 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
917 				struct t10_pr_registration *, enum register_type, int);
918 
919 static int __core_scsi3_check_aptpl_registration(
920 	struct se_device *dev,
921 	struct se_portal_group *tpg,
922 	struct se_lun *lun,
923 	u64 target_lun,
924 	struct se_node_acl *nacl,
925 	u64 mapped_lun)
926 {
927 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
928 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
929 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN] = { };
930 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN] = { };
931 	u16 tpgt;
932 
933 	/*
934 	 * Copy Initiator Port information from struct se_node_acl
935 	 */
936 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
937 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
938 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
939 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
940 	/*
941 	 * Look for the matching registrations+reservation from those
942 	 * created from APTPL metadata.  Note that multiple registrations
943 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
944 	 * TransportIDs.
945 	 */
946 	spin_lock(&pr_tmpl->aptpl_reg_lock);
947 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
948 				pr_reg_aptpl_list) {
949 
950 		if (!strcmp(pr_reg->pr_iport, i_port) &&
951 		     (pr_reg->pr_res_mapped_lun == mapped_lun) &&
952 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
953 		     (pr_reg->pr_reg_tpgt == tpgt) &&
954 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
955 			/*
956 			 * Obtain the ->pr_reg_deve pointer + reference, that
957 			 * is released by __core_scsi3_add_registration() below.
958 			 */
959 			rcu_read_lock();
960 			pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
961 			if (!pr_reg->pr_reg_deve) {
962 				pr_err("Unable to locate PR APTPL %s mapped_lun:"
963 					" %llu\n", nacl->initiatorname, mapped_lun);
964 				rcu_read_unlock();
965 				continue;
966 			}
967 			kref_get(&pr_reg->pr_reg_deve->pr_kref);
968 			rcu_read_unlock();
969 
970 			pr_reg->pr_reg_nacl = nacl;
971 			pr_reg->tg_pt_sep_rtpi = lun->lun_tpg->tpg_rtpi;
972 			list_del(&pr_reg->pr_reg_aptpl_list);
973 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
974 			/*
975 			 * At this point all of the pointers in *pr_reg will
976 			 * be setup, so go ahead and add the registration.
977 			 */
978 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
979 			/*
980 			 * If this registration is the reservation holder,
981 			 * make that happen now..
982 			 */
983 			if (pr_reg->pr_res_holder)
984 				core_scsi3_aptpl_reserve(dev, tpg,
985 						nacl, pr_reg);
986 			/*
987 			 * Reenable pr_aptpl_active to accept new metadata
988 			 * updates once the SCSI device is active again..
989 			 */
990 			spin_lock(&pr_tmpl->aptpl_reg_lock);
991 			pr_tmpl->pr_aptpl_active = 1;
992 		}
993 	}
994 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
995 
996 	return 0;
997 }
998 
999 int core_scsi3_check_aptpl_registration(
1000 	struct se_device *dev,
1001 	struct se_portal_group *tpg,
1002 	struct se_lun *lun,
1003 	struct se_node_acl *nacl,
1004 	u64 mapped_lun)
1005 {
1006 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
1007 		return 0;
1008 
1009 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
1010 						     lun->unpacked_lun, nacl,
1011 						     mapped_lun);
1012 }
1013 
1014 static void __core_scsi3_dump_registration(
1015 	const struct target_core_fabric_ops *tfo,
1016 	struct se_device *dev,
1017 	struct se_node_acl *nacl,
1018 	struct t10_pr_registration *pr_reg,
1019 	enum register_type register_type)
1020 {
1021 	struct se_portal_group *se_tpg = nacl->se_tpg;
1022 	char i_buf[PR_REG_ISID_ID_LEN] = { };
1023 
1024 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1025 
1026 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1027 		" Node: %s%s\n", tfo->fabric_name, (register_type == REGISTER_AND_MOVE) ?
1028 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
1029 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1030 		i_buf);
1031 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1032 		 tfo->fabric_name, tfo->tpg_get_wwn(se_tpg),
1033 		tfo->tpg_get_tag(se_tpg));
1034 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1035 		" Port(s)\n",  tfo->fabric_name,
1036 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1037 		dev->transport->name);
1038 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1039 		" 0x%08x  APTPL: %d\n", tfo->fabric_name,
1040 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1041 		pr_reg->pr_reg_aptpl);
1042 }
1043 
1044 static void __core_scsi3_add_registration(
1045 	struct se_device *dev,
1046 	struct se_node_acl *nacl,
1047 	struct t10_pr_registration *pr_reg,
1048 	enum register_type register_type,
1049 	int register_move)
1050 {
1051 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1052 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1053 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1054 	struct se_dev_entry *deve;
1055 
1056 	/*
1057 	 * Increment PRgeneration counter for struct se_device upon a successful
1058 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1059 	 *
1060 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1061 	 * action, the struct se_device->dev_reservation_lock will already be held,
1062 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1063 	 * for the REGISTER.
1064 	 */
1065 	pr_reg->pr_res_generation = (register_move) ?
1066 			dev->t10_pr.pr_generation++ :
1067 			core_scsi3_pr_generation(dev);
1068 
1069 	spin_lock(&pr_tmpl->registration_lock);
1070 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1071 
1072 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1073 	spin_unlock(&pr_tmpl->registration_lock);
1074 	/*
1075 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1076 	 */
1077 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1078 		goto out;
1079 	/*
1080 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1081 	 * allocated in __core_scsi3_alloc_registration()
1082 	 */
1083 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1084 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1085 		struct se_node_acl *nacl_tmp = pr_reg_tmp->pr_reg_nacl;
1086 
1087 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1088 
1089 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1090 
1091 		spin_lock(&pr_tmpl->registration_lock);
1092 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1093 			      &pr_tmpl->registration_list);
1094 
1095 		__core_scsi3_dump_registration(tfo, dev, nacl_tmp, pr_reg_tmp,
1096 					       register_type);
1097 		spin_unlock(&pr_tmpl->registration_lock);
1098 		/*
1099 		 * Drop configfs group dependency reference and deve->pr_kref
1100 		 * obtained from  __core_scsi3_alloc_registration() code.
1101 		 */
1102 		rcu_read_lock();
1103 		deve = pr_reg_tmp->pr_reg_deve;
1104 		if (deve) {
1105 			set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1106 			core_scsi3_lunacl_undepend_item(deve);
1107 			pr_reg_tmp->pr_reg_deve = NULL;
1108 		}
1109 		rcu_read_unlock();
1110 	}
1111 out:
1112 	/*
1113 	 * Drop deve->pr_kref obtained in __core_scsi3_do_alloc_registration()
1114 	 */
1115 	rcu_read_lock();
1116 	deve = pr_reg->pr_reg_deve;
1117 	if (deve) {
1118 		set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1119 		kref_put(&deve->pr_kref, target_pr_kref_release);
1120 		pr_reg->pr_reg_deve = NULL;
1121 	}
1122 	rcu_read_unlock();
1123 }
1124 
1125 static int core_scsi3_alloc_registration(
1126 	struct se_device *dev,
1127 	struct se_node_acl *nacl,
1128 	struct se_lun *lun,
1129 	struct se_dev_entry *deve,
1130 	u64 mapped_lun,
1131 	unsigned char *isid,
1132 	u64 sa_res_key,
1133 	int all_tg_pt,
1134 	int aptpl,
1135 	enum register_type register_type,
1136 	int register_move)
1137 {
1138 	struct t10_pr_registration *pr_reg;
1139 
1140 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, lun, deve, mapped_lun,
1141 						 isid, sa_res_key, all_tg_pt,
1142 						 aptpl);
1143 	if (!pr_reg)
1144 		return -EPERM;
1145 
1146 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1147 			register_type, register_move);
1148 	return 0;
1149 }
1150 
1151 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1152 	struct se_device *dev,
1153 	struct se_node_acl *nacl,
1154 	unsigned char *isid)
1155 {
1156 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1157 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1158 
1159 	spin_lock(&pr_tmpl->registration_lock);
1160 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1161 			&pr_tmpl->registration_list, pr_reg_list) {
1162 		/*
1163 		 * First look for a matching struct se_node_acl
1164 		 */
1165 		if (pr_reg->pr_reg_nacl != nacl)
1166 			continue;
1167 
1168 		/*
1169 		 * If this registration does NOT contain a fabric provided
1170 		 * ISID, then we have found a match.
1171 		 */
1172 		if (!pr_reg->isid_present_at_reg) {
1173 			atomic_inc_mb(&pr_reg->pr_res_holders);
1174 			spin_unlock(&pr_tmpl->registration_lock);
1175 			return pr_reg;
1176 		}
1177 		/*
1178 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1179 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1180 		 * matching ISID to be provided by the local SCSI Initiator Port.
1181 		 */
1182 		if (!isid)
1183 			continue;
1184 		if (strcmp(isid, pr_reg->pr_reg_isid))
1185 			continue;
1186 
1187 		atomic_inc_mb(&pr_reg->pr_res_holders);
1188 		spin_unlock(&pr_tmpl->registration_lock);
1189 		return pr_reg;
1190 	}
1191 	spin_unlock(&pr_tmpl->registration_lock);
1192 
1193 	return NULL;
1194 }
1195 
1196 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1197 	struct se_device *dev,
1198 	struct se_node_acl *nacl,
1199 	struct se_session *sess)
1200 {
1201 	struct se_portal_group *tpg = nacl->se_tpg;
1202 	unsigned char buf[PR_REG_ISID_LEN] = { };
1203 	unsigned char *isid_ptr = NULL;
1204 
1205 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1206 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1207 					PR_REG_ISID_LEN);
1208 		isid_ptr = &buf[0];
1209 	}
1210 
1211 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1212 }
1213 
1214 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1215 {
1216 	atomic_dec_mb(&pr_reg->pr_res_holders);
1217 }
1218 
1219 static int core_scsi3_check_implicit_release(
1220 	struct se_device *dev,
1221 	struct t10_pr_registration *pr_reg)
1222 {
1223 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1224 	struct t10_pr_registration *pr_res_holder;
1225 	int ret = 0;
1226 
1227 	spin_lock(&dev->dev_reservation_lock);
1228 	pr_res_holder = dev->dev_pr_res_holder;
1229 	if (!pr_res_holder) {
1230 		spin_unlock(&dev->dev_reservation_lock);
1231 		return ret;
1232 	}
1233 	if (pr_res_holder == pr_reg) {
1234 		/*
1235 		 * Perform an implicit RELEASE if the registration that
1236 		 * is being released is holding the reservation.
1237 		 *
1238 		 * From spc4r17, section 5.7.11.1:
1239 		 *
1240 		 * e) If the I_T nexus is the persistent reservation holder
1241 		 *    and the persistent reservation is not an all registrants
1242 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1243 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1244 		 *    service action with the SERVICE ACTION RESERVATION KEY
1245 		 *    field set to zero (see 5.7.11.3).
1246 		 */
1247 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1248 		ret = 1;
1249 		/*
1250 		 * For 'All Registrants' reservation types, all existing
1251 		 * registrations are still processed as reservation holders
1252 		 * in core_scsi3_pr_seq_non_holder() after the initial
1253 		 * reservation holder is implicitly released here.
1254 		 */
1255 	} else if (pr_reg->pr_reg_all_tg_pt &&
1256 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1257 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1258 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1259 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1260 			" UNREGISTER while existing reservation with matching"
1261 			" key 0x%016Lx is present from another SCSI Initiator"
1262 			" Port\n", pr_reg->pr_res_key);
1263 		ret = -EPERM;
1264 	}
1265 	spin_unlock(&dev->dev_reservation_lock);
1266 
1267 	return ret;
1268 }
1269 
1270 static void __core_scsi3_free_registration(
1271 	struct se_device *dev,
1272 	struct t10_pr_registration *pr_reg,
1273 	struct list_head *preempt_and_abort_list,
1274 	int dec_holders)
1275 	__releases(&pr_tmpl->registration_lock)
1276 	__acquires(&pr_tmpl->registration_lock)
1277 {
1278 	const struct target_core_fabric_ops *tfo =
1279 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1280 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1281 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1282 	struct se_dev_entry *deve;
1283 	char i_buf[PR_REG_ISID_ID_LEN] = { };
1284 
1285 	lockdep_assert_held(&pr_tmpl->registration_lock);
1286 
1287 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1288 
1289 	if (!list_empty(&pr_reg->pr_reg_list))
1290 		list_del(&pr_reg->pr_reg_list);
1291 	/*
1292 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1293 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1294 	 */
1295 	if (dec_holders)
1296 		core_scsi3_put_pr_reg(pr_reg);
1297 
1298 	spin_unlock(&pr_tmpl->registration_lock);
1299 	/*
1300 	 * Wait until all reference from any other I_T nexuses for this
1301 	 * *pr_reg have been released.  Because list_del() is called above,
1302 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1303 	 * count back to zero, and we release *pr_reg.
1304 	 */
1305 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1306 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1307 				tfo->fabric_name);
1308 		cpu_relax();
1309 	}
1310 
1311 	rcu_read_lock();
1312 	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
1313 	if (deve)
1314 		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1315 	rcu_read_unlock();
1316 
1317 	spin_lock(&pr_tmpl->registration_lock);
1318 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1319 		" Node: %s%s\n", tfo->fabric_name,
1320 		pr_reg->pr_reg_nacl->initiatorname,
1321 		i_buf);
1322 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1323 		" Port(s)\n", tfo->fabric_name,
1324 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1325 		dev->transport->name);
1326 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1327 		" 0x%08x\n", tfo->fabric_name, pr_reg->pr_res_key,
1328 		pr_reg->pr_res_generation);
1329 
1330 	if (!preempt_and_abort_list) {
1331 		pr_reg->pr_reg_deve = NULL;
1332 		pr_reg->pr_reg_nacl = NULL;
1333 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1334 		return;
1335 	}
1336 	/*
1337 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1338 	 * are released once the ABORT_TASK_SET has completed..
1339 	 */
1340 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1341 }
1342 
1343 void core_scsi3_free_pr_reg_from_nacl(
1344 	struct se_device *dev,
1345 	struct se_node_acl *nacl)
1346 {
1347 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1348 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1349 	bool free_reg = false;
1350 	/*
1351 	 * If the passed se_node_acl matches the reservation holder,
1352 	 * release the reservation.
1353 	 */
1354 	spin_lock(&dev->dev_reservation_lock);
1355 	pr_res_holder = dev->dev_pr_res_holder;
1356 	if ((pr_res_holder != NULL) &&
1357 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1358 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1359 		free_reg = true;
1360 	}
1361 	spin_unlock(&dev->dev_reservation_lock);
1362 	/*
1363 	 * Release any registration associated with the struct se_node_acl.
1364 	 */
1365 	spin_lock(&pr_tmpl->registration_lock);
1366 	if (pr_res_holder && free_reg)
1367 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1368 
1369 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1370 			&pr_tmpl->registration_list, pr_reg_list) {
1371 
1372 		if (pr_reg->pr_reg_nacl != nacl)
1373 			continue;
1374 
1375 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1376 	}
1377 	spin_unlock(&pr_tmpl->registration_lock);
1378 }
1379 
1380 void core_scsi3_free_all_registrations(
1381 	struct se_device *dev)
1382 {
1383 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1384 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1385 
1386 	spin_lock(&dev->dev_reservation_lock);
1387 	pr_res_holder = dev->dev_pr_res_holder;
1388 	if (pr_res_holder != NULL) {
1389 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1390 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1391 						  pr_res_holder, 0, 0);
1392 	}
1393 	spin_unlock(&dev->dev_reservation_lock);
1394 
1395 	spin_lock(&pr_tmpl->registration_lock);
1396 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1397 			&pr_tmpl->registration_list, pr_reg_list) {
1398 
1399 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1400 	}
1401 	spin_unlock(&pr_tmpl->registration_lock);
1402 
1403 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1404 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1405 				pr_reg_aptpl_list) {
1406 		list_del(&pr_reg->pr_reg_aptpl_list);
1407 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1408 	}
1409 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1410 }
1411 
1412 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1413 {
1414 	return target_depend_item(&tpg->tpg_group.cg_item);
1415 }
1416 
1417 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1418 {
1419 	target_undepend_item(&tpg->tpg_group.cg_item);
1420 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1421 }
1422 
1423 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1424 {
1425 	if (nacl->dynamic_node_acl)
1426 		return 0;
1427 	return target_depend_item(&nacl->acl_group.cg_item);
1428 }
1429 
1430 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1431 {
1432 	if (!nacl->dynamic_node_acl)
1433 		target_undepend_item(&nacl->acl_group.cg_item);
1434 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1435 }
1436 
1437 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1438 {
1439 	/*
1440 	 * For nacl->dynamic_node_acl=1
1441 	 */
1442 	if (!se_deve->se_lun_acl)
1443 		return 0;
1444 
1445 	return target_depend_item(&se_deve->se_lun_acl->se_lun_group.cg_item);
1446 }
1447 
1448 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1449 {
1450 	/*
1451 	 * For nacl->dynamic_node_acl=1
1452 	 */
1453 	if (!se_deve->se_lun_acl) {
1454 		kref_put(&se_deve->pr_kref, target_pr_kref_release);
1455 		return;
1456 	}
1457 
1458 	target_undepend_item(&se_deve->se_lun_acl->se_lun_group.cg_item);
1459 	kref_put(&se_deve->pr_kref, target_pr_kref_release);
1460 }
1461 
1462 static sense_reason_t
1463 core_scsi3_decode_spec_i_port(
1464 	struct se_cmd *cmd,
1465 	struct se_portal_group *tpg,
1466 	unsigned char *l_isid,
1467 	u64 sa_res_key,
1468 	int all_tg_pt,
1469 	int aptpl)
1470 {
1471 	struct se_device *dev = cmd->se_dev;
1472 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1473 	struct se_session *se_sess = cmd->se_sess;
1474 	struct se_node_acl *dest_node_acl = NULL;
1475 	struct se_dev_entry *dest_se_deve = NULL;
1476 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1477 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1478 	LIST_HEAD(tid_dest_list);
1479 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1480 	unsigned char *buf, *ptr, proto_ident;
1481 	const unsigned char *i_str = NULL;
1482 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1483 	sense_reason_t ret;
1484 	u32 tpdl, tid_len = 0;
1485 	u32 dest_rtpi = 0;
1486 
1487 	/*
1488 	 * Allocate a struct pr_transport_id_holder and setup the
1489 	 * local_node_acl pointer and add to struct list_head tid_dest_list
1490 	 * for add registration processing in the loop of tid_dest_list below.
1491 	 */
1492 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1493 	if (!tidh_new) {
1494 		pr_err("Unable to allocate tidh_new\n");
1495 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1496 	}
1497 	INIT_LIST_HEAD(&tidh_new->dest_list);
1498 	tidh_new->dest_tpg = tpg;
1499 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1500 
1501 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1502 				se_sess->se_node_acl, cmd->se_lun,
1503 				NULL, cmd->orig_fe_lun, l_isid,
1504 				sa_res_key, all_tg_pt, aptpl);
1505 	if (!local_pr_reg) {
1506 		kfree(tidh_new);
1507 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1508 	}
1509 
1510 	if (core_scsi3_lunacl_depend_item(local_pr_reg->pr_reg_deve)) {
1511 		kfree(tidh_new);
1512 		kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1513 			 target_pr_kref_release);
1514 		kmem_cache_free(t10_pr_reg_cache, local_pr_reg);
1515 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1516 	}
1517 
1518 	tidh_new->dest_pr_reg = local_pr_reg;
1519 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1520 
1521 	if (cmd->data_length < 28) {
1522 		pr_warn("SPC-PR: Received PR OUT parameter list"
1523 			" length too small: %u\n", cmd->data_length);
1524 		ret = TCM_INVALID_PARAMETER_LIST;
1525 		goto out;
1526 	}
1527 
1528 	buf = transport_kmap_data_sg(cmd);
1529 	if (!buf) {
1530 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1531 		goto out;
1532 	}
1533 
1534 	/*
1535 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1536 	 * first extract TransportID Parameter Data Length, and make sure
1537 	 * the value matches up to the SCSI expected data transfer length.
1538 	 */
1539 	tpdl = get_unaligned_be32(&buf[24]);
1540 
1541 	if ((tpdl + 28) != cmd->data_length) {
1542 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1543 			" does not equal CDB data_length: %u\n", tpdl,
1544 			cmd->data_length);
1545 		ret = TCM_INVALID_PARAMETER_LIST;
1546 		goto out_unmap;
1547 	}
1548 	/*
1549 	 * Start processing the received transport IDs using the
1550 	 * receiving I_T Nexus portal's fabric dependent methods to
1551 	 * obtain the SCSI Initiator Port/Device Identifiers.
1552 	 */
1553 	ptr = &buf[28];
1554 
1555 	while (tpdl > 0) {
1556 		struct se_lun *dest_lun, *tmp_lun;
1557 
1558 		proto_ident = (ptr[0] & 0x0f);
1559 		dest_tpg = NULL;
1560 
1561 		spin_lock(&dev->se_port_lock);
1562 		list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
1563 			tmp_tpg = tmp_lun->lun_tpg;
1564 
1565 			/*
1566 			 * Look for the matching proto_ident provided by
1567 			 * the received TransportID
1568 			 */
1569 			if (tmp_tpg->proto_id != proto_ident)
1570 				continue;
1571 			dest_rtpi = tmp_lun->lun_tpg->tpg_rtpi;
1572 
1573 			iport_ptr = NULL;
1574 			i_str = target_parse_pr_out_transport_id(tmp_tpg,
1575 					ptr, &tid_len, &iport_ptr);
1576 			if (!i_str)
1577 				continue;
1578 			/*
1579 			 * Determine if this SCSI device server requires that
1580 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1581 			 * for fabric modules (iSCSI) requiring them.
1582 			 */
1583 			if (tpg->se_tpg_tfo->sess_get_initiator_sid &&
1584 			    dev->dev_attrib.enforce_pr_isids &&
1585 			    !iport_ptr) {
1586 				pr_warn("SPC-PR: enforce_pr_isids is set but a isid has not been sent in the SPEC_I_PT data for %s.",
1587 					i_str);
1588 				ret = TCM_INVALID_PARAMETER_LIST;
1589 				spin_unlock(&dev->se_port_lock);
1590 				goto out_unmap;
1591 			}
1592 
1593 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1594 			spin_unlock(&dev->se_port_lock);
1595 
1596 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1597 				pr_err(" core_scsi3_tpg_depend_item()"
1598 					" for tmp_tpg\n");
1599 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1600 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1601 				goto out_unmap;
1602 			}
1603 			/*
1604 			 * Locate the destination initiator ACL to be registered
1605 			 * from the decoded fabric module specific TransportID
1606 			 * at *i_str.
1607 			 */
1608 			mutex_lock(&tmp_tpg->acl_node_mutex);
1609 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1610 						tmp_tpg, i_str);
1611 			if (dest_node_acl)
1612 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1613 			mutex_unlock(&tmp_tpg->acl_node_mutex);
1614 
1615 			if (!dest_node_acl) {
1616 				core_scsi3_tpg_undepend_item(tmp_tpg);
1617 				spin_lock(&dev->se_port_lock);
1618 				continue;
1619 			}
1620 
1621 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1622 				pr_err("configfs_depend_item() failed"
1623 					" for dest_node_acl->acl_group\n");
1624 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1625 				core_scsi3_tpg_undepend_item(tmp_tpg);
1626 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1627 				goto out_unmap;
1628 			}
1629 
1630 			dest_tpg = tmp_tpg;
1631 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s Port RTPI: %u\n",
1632 				dest_tpg->se_tpg_tfo->fabric_name,
1633 				dest_node_acl->initiatorname, dest_rtpi);
1634 
1635 			spin_lock(&dev->se_port_lock);
1636 			break;
1637 		}
1638 		spin_unlock(&dev->se_port_lock);
1639 
1640 		if (!dest_tpg) {
1641 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1642 					" dest_tpg\n");
1643 			ret = TCM_INVALID_PARAMETER_LIST;
1644 			goto out_unmap;
1645 		}
1646 
1647 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1648 			" tid_len: %d for %s + %s\n",
1649 			dest_tpg->se_tpg_tfo->fabric_name, cmd->data_length,
1650 			tpdl, tid_len, i_str, iport_ptr);
1651 
1652 		if (tid_len > tpdl) {
1653 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1654 				" %u for Transport ID: %s\n", tid_len, ptr);
1655 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1656 			core_scsi3_tpg_undepend_item(dest_tpg);
1657 			ret = TCM_INVALID_PARAMETER_LIST;
1658 			goto out_unmap;
1659 		}
1660 		/*
1661 		 * Locate the desintation struct se_dev_entry pointer for matching
1662 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1663 		 * Target Port.
1664 		 */
1665 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1666 					dest_rtpi);
1667 		if (!dest_se_deve) {
1668 			pr_err("Unable to locate %s dest_se_deve from destination RTPI: %u\n",
1669 				dest_tpg->se_tpg_tfo->fabric_name,
1670 				dest_rtpi);
1671 
1672 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1673 			core_scsi3_tpg_undepend_item(dest_tpg);
1674 			ret = TCM_INVALID_PARAMETER_LIST;
1675 			goto out_unmap;
1676 		}
1677 
1678 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1679 			pr_err("core_scsi3_lunacl_depend_item()"
1680 					" failed\n");
1681 			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
1682 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1683 			core_scsi3_tpg_undepend_item(dest_tpg);
1684 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1685 			goto out_unmap;
1686 		}
1687 
1688 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1689 			" dest_se_deve mapped_lun: %llu\n",
1690 			dest_tpg->se_tpg_tfo->fabric_name,
1691 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1692 
1693 		/*
1694 		 * Skip any TransportIDs that already have a registration for
1695 		 * this target port.
1696 		 */
1697 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1698 					iport_ptr);
1699 		if (pr_reg_e) {
1700 			core_scsi3_put_pr_reg(pr_reg_e);
1701 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1702 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1703 			core_scsi3_tpg_undepend_item(dest_tpg);
1704 			ptr += tid_len;
1705 			tpdl -= tid_len;
1706 			tid_len = 0;
1707 			continue;
1708 		}
1709 		/*
1710 		 * Allocate a struct pr_transport_id_holder and setup
1711 		 * the dest_node_acl and dest_se_deve pointers for the
1712 		 * loop below.
1713 		 */
1714 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1715 				GFP_KERNEL);
1716 		if (!tidh_new) {
1717 			pr_err("Unable to allocate tidh_new\n");
1718 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1719 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1720 			core_scsi3_tpg_undepend_item(dest_tpg);
1721 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1722 			goto out_unmap;
1723 		}
1724 		INIT_LIST_HEAD(&tidh_new->dest_list);
1725 		tidh_new->dest_tpg = dest_tpg;
1726 		tidh_new->dest_node_acl = dest_node_acl;
1727 		tidh_new->dest_se_deve = dest_se_deve;
1728 
1729 		/*
1730 		 * Allocate, but do NOT add the registration for the
1731 		 * TransportID referenced SCSI Initiator port.  This
1732 		 * done because of the following from spc4r17 in section
1733 		 * 6.14.3 wrt SPEC_I_PT:
1734 		 *
1735 		 * "If a registration fails for any initiator port (e.g., if th
1736 		 * logical unit does not have enough resources available to
1737 		 * hold the registration information), no registrations shall be
1738 		 * made, and the command shall be terminated with
1739 		 * CHECK CONDITION status."
1740 		 *
1741 		 * That means we call __core_scsi3_alloc_registration() here,
1742 		 * and then call __core_scsi3_add_registration() in the
1743 		 * 2nd loop which will never fail.
1744 		 */
1745 		dest_lun = dest_se_deve->se_lun;
1746 
1747 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1748 					dest_node_acl, dest_lun, dest_se_deve,
1749 					dest_se_deve->mapped_lun, iport_ptr,
1750 					sa_res_key, all_tg_pt, aptpl);
1751 		if (!dest_pr_reg) {
1752 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1753 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1754 			core_scsi3_tpg_undepend_item(dest_tpg);
1755 			kfree(tidh_new);
1756 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1757 			goto out_unmap;
1758 		}
1759 		tidh_new->dest_pr_reg = dest_pr_reg;
1760 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1761 
1762 		ptr += tid_len;
1763 		tpdl -= tid_len;
1764 		tid_len = 0;
1765 
1766 	}
1767 
1768 	transport_kunmap_data_sg(cmd);
1769 
1770 	/*
1771 	 * Go ahead and create a registrations from tid_dest_list for the
1772 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1773 	 * and dest_se_deve.
1774 	 *
1775 	 * The SA Reservation Key from the PROUT is set for the
1776 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1777 	 * means that the TransportID Initiator port will be
1778 	 * registered on all of the target ports in the SCSI target device
1779 	 * ALL_TG_PT=0 means the registration will only be for the
1780 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1781 	 * was received.
1782 	 */
1783 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1784 		dest_tpg = tidh->dest_tpg;
1785 		dest_node_acl = tidh->dest_node_acl;
1786 		dest_se_deve = tidh->dest_se_deve;
1787 		dest_pr_reg = tidh->dest_pr_reg;
1788 
1789 		list_del(&tidh->dest_list);
1790 		kfree(tidh);
1791 
1792 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1793 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1794 
1795 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1796 					dest_pr_reg, 0, 0);
1797 
1798 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1799 			" registered Transport ID for Node: %s%s Mapped LUN:"
1800 			" %llu\n", dest_tpg->se_tpg_tfo->fabric_name,
1801 			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
1802 			dest_se_deve->mapped_lun : 0);
1803 
1804 		if (dest_pr_reg == local_pr_reg)
1805 			continue;
1806 
1807 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1808 		core_scsi3_tpg_undepend_item(dest_tpg);
1809 	}
1810 
1811 	return 0;
1812 out_unmap:
1813 	transport_kunmap_data_sg(cmd);
1814 out:
1815 	/*
1816 	 * For the failure case, release everything from tid_dest_list
1817 	 * including *dest_pr_reg and the configfs dependances..
1818 	 */
1819 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1820 		bool is_local = false;
1821 
1822 		dest_tpg = tidh->dest_tpg;
1823 		dest_node_acl = tidh->dest_node_acl;
1824 		dest_se_deve = tidh->dest_se_deve;
1825 		dest_pr_reg = tidh->dest_pr_reg;
1826 
1827 		if (dest_pr_reg == local_pr_reg)
1828 			is_local = true;
1829 
1830 		list_del(&tidh->dest_list);
1831 		kfree(tidh);
1832 		/*
1833 		 * Release any extra ALL_TG_PT=1 registrations for
1834 		 * the SPEC_I_PT=1 case.
1835 		 */
1836 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1837 				&dest_pr_reg->pr_reg_atp_list,
1838 				pr_reg_atp_mem_list) {
1839 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1840 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1841 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1842 		}
1843 
1844 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1845 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1846 
1847 		if (is_local)
1848 			continue;
1849 
1850 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1851 		core_scsi3_tpg_undepend_item(dest_tpg);
1852 	}
1853 	return ret;
1854 }
1855 
1856 static int core_scsi3_update_aptpl_buf(
1857 	struct se_device *dev,
1858 	unsigned char *buf,
1859 	u32 pr_aptpl_buf_len)
1860 {
1861 	struct se_portal_group *tpg;
1862 	struct t10_pr_registration *pr_reg;
1863 	unsigned char tmp[512], isid_buf[32];
1864 	ssize_t len = 0;
1865 	int reg_count = 0;
1866 	int ret = 0;
1867 
1868 	spin_lock(&dev->dev_reservation_lock);
1869 	spin_lock(&dev->t10_pr.registration_lock);
1870 	/*
1871 	 * Walk the registration list..
1872 	 */
1873 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1874 			pr_reg_list) {
1875 
1876 		tmp[0] = '\0';
1877 		isid_buf[0] = '\0';
1878 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1879 		/*
1880 		 * Write out any ISID value to APTPL metadata that was included
1881 		 * in the original registration.
1882 		 */
1883 		if (pr_reg->isid_present_at_reg)
1884 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1885 					pr_reg->pr_reg_isid);
1886 		/*
1887 		 * Include special metadata if the pr_reg matches the
1888 		 * reservation holder.
1889 		 */
1890 		if (dev->dev_pr_res_holder == pr_reg) {
1891 			snprintf(tmp, 512, "PR_REG_START: %d"
1892 				"\ninitiator_fabric=%s\n"
1893 				"initiator_node=%s\n%s"
1894 				"sa_res_key=%llu\n"
1895 				"res_holder=1\nres_type=%02x\n"
1896 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1897 				"mapped_lun=%llu\n", reg_count,
1898 				tpg->se_tpg_tfo->fabric_name,
1899 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1900 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1901 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1902 				pr_reg->pr_res_mapped_lun);
1903 		} else {
1904 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1905 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1906 				"sa_res_key=%llu\nres_holder=0\n"
1907 				"res_all_tg_pt=%d\nmapped_lun=%llu\n",
1908 				reg_count, tpg->se_tpg_tfo->fabric_name,
1909 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1910 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1911 				pr_reg->pr_res_mapped_lun);
1912 		}
1913 
1914 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1915 			pr_err("Unable to update renaming APTPL metadata,"
1916 			       " reallocating larger buffer\n");
1917 			ret = -EMSGSIZE;
1918 			goto out;
1919 		}
1920 		len += sprintf(buf+len, "%s", tmp);
1921 
1922 		/*
1923 		 * Include information about the associated SCSI target port.
1924 		 */
1925 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1926 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%llu\nPR_REG_END:"
1927 			" %d\n", tpg->se_tpg_tfo->fabric_name,
1928 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1929 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1930 			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
1931 			reg_count);
1932 
1933 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1934 			pr_err("Unable to update renaming APTPL metadata,"
1935 			       " reallocating larger buffer\n");
1936 			ret = -EMSGSIZE;
1937 			goto out;
1938 		}
1939 		len += sprintf(buf+len, "%s", tmp);
1940 		reg_count++;
1941 	}
1942 
1943 	if (!reg_count)
1944 		len += sprintf(buf+len, "No Registrations or Reservations");
1945 
1946 out:
1947 	spin_unlock(&dev->t10_pr.registration_lock);
1948 	spin_unlock(&dev->dev_reservation_lock);
1949 
1950 	return ret;
1951 }
1952 
1953 static int __core_scsi3_write_aptpl_to_file(
1954 	struct se_device *dev,
1955 	unsigned char *buf)
1956 {
1957 	struct t10_wwn *wwn = &dev->t10_wwn;
1958 	struct file *file;
1959 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1960 	char *path;
1961 	u32 pr_aptpl_buf_len;
1962 	int ret;
1963 	loff_t pos = 0;
1964 
1965 	path = kasprintf(GFP_KERNEL, "%s/pr/aptpl_%s", db_root,
1966 			&wwn->unit_serial[0]);
1967 	if (!path)
1968 		return -ENOMEM;
1969 
1970 	file = filp_open(path, flags, 0600);
1971 	if (IS_ERR(file)) {
1972 		pr_err("filp_open(%s) for APTPL metadata"
1973 			" failed\n", path);
1974 		kfree(path);
1975 		return PTR_ERR(file);
1976 	}
1977 
1978 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1979 
1980 	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);
1981 
1982 	if (ret < 0)
1983 		pr_debug("Error writing APTPL metadata file: %s\n", path);
1984 	fput(file);
1985 	kfree(path);
1986 
1987 	return (ret < 0) ? -EIO : 0;
1988 }
1989 
1990 /*
1991  * Clear the APTPL metadata if APTPL has been disabled, otherwise
1992  * write out the updated metadata to struct file for this SCSI device.
1993  */
1994 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
1995 {
1996 	unsigned char *buf;
1997 	int rc, len = PR_APTPL_BUF_LEN;
1998 
1999 	if (!aptpl) {
2000 		char *null_buf = "No Registrations or Reservations\n";
2001 
2002 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
2003 		dev->t10_pr.pr_aptpl_active = 0;
2004 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
2005 
2006 		if (rc)
2007 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2008 
2009 		return 0;
2010 	}
2011 retry:
2012 	buf = vzalloc(len);
2013 	if (!buf)
2014 		return TCM_OUT_OF_RESOURCES;
2015 
2016 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
2017 	if (rc < 0) {
2018 		vfree(buf);
2019 		len *= 2;
2020 		goto retry;
2021 	}
2022 
2023 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2024 	if (rc != 0) {
2025 		pr_err("SPC-3 PR: Could not update APTPL\n");
2026 		vfree(buf);
2027 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2028 	}
2029 	dev->t10_pr.pr_aptpl_active = 1;
2030 	vfree(buf);
2031 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2032 	return 0;
2033 }
2034 
2035 static sense_reason_t
2036 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2037 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2038 {
2039 	struct se_session *se_sess = cmd->se_sess;
2040 	struct se_device *dev = cmd->se_dev;
2041 	struct se_lun *se_lun = cmd->se_lun;
2042 	struct se_portal_group *se_tpg;
2043 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2044 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2045 	unsigned char isid_buf[PR_REG_ISID_LEN] = { };
2046 	unsigned char *isid_ptr = NULL;
2047 	sense_reason_t ret = TCM_NO_SENSE;
2048 	int pr_holder = 0, type;
2049 
2050 	if (!se_sess || !se_lun) {
2051 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2052 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2053 	}
2054 	se_tpg = se_sess->se_tpg;
2055 
2056 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2057 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2058 				PR_REG_ISID_LEN);
2059 		isid_ptr = &isid_buf[0];
2060 	}
2061 	/*
2062 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2063 	 */
2064 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2065 	if (!pr_reg) {
2066 		if (res_key) {
2067 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2068 				" for SA REGISTER, returning CONFLICT\n");
2069 			return TCM_RESERVATION_CONFLICT;
2070 		}
2071 		/*
2072 		 * Do nothing but return GOOD status.
2073 		 */
2074 		if (!sa_res_key)
2075 			return 0;
2076 
2077 		if (!spec_i_pt) {
2078 			/*
2079 			 * Perform the Service Action REGISTER on the Initiator
2080 			 * Port Endpoint that the PRO was received from on the
2081 			 * Logical Unit of the SCSI device server.
2082 			 */
2083 			if (core_scsi3_alloc_registration(cmd->se_dev,
2084 					se_sess->se_node_acl, cmd->se_lun,
2085 					NULL, cmd->orig_fe_lun, isid_ptr,
2086 					sa_res_key, all_tg_pt, aptpl,
2087 					register_type, 0)) {
2088 				pr_err("Unable to allocate"
2089 					" struct t10_pr_registration\n");
2090 				return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
2091 			}
2092 		} else {
2093 			/*
2094 			 * Register both the Initiator port that received
2095 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2096 			 * TransportID from Parameter list and loop through
2097 			 * fabric dependent parameter list while calling
2098 			 * logic from of core_scsi3_alloc_registration() for
2099 			 * each TransportID provided SCSI Initiator Port/Device
2100 			 */
2101 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2102 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2103 			if (ret != 0)
2104 				return ret;
2105 		}
2106 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2107 	}
2108 
2109 	/* ok, existing registration */
2110 
2111 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2112 		pr_err("SPC-3 PR REGISTER: Received"
2113 		       " res_key: 0x%016Lx does not match"
2114 		       " existing SA REGISTER res_key:"
2115 		       " 0x%016Lx\n", res_key,
2116 		       pr_reg->pr_res_key);
2117 		ret = TCM_RESERVATION_CONFLICT;
2118 		goto out;
2119 	}
2120 
2121 	if (spec_i_pt) {
2122 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2123 			" set on a registered nexus\n");
2124 		ret = TCM_INVALID_PARAMETER_LIST;
2125 		goto out;
2126 	}
2127 
2128 	/*
2129 	 * An existing ALL_TG_PT=1 registration being released
2130 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2131 	 */
2132 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2133 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2134 			" registration exists, but ALL_TG_PT=1 bit not"
2135 			" present in received PROUT\n");
2136 		ret = TCM_INVALID_CDB_FIELD;
2137 		goto out;
2138 	}
2139 
2140 	/*
2141 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2142 	 */
2143 	if (sa_res_key) {
2144 		/*
2145 		 * Increment PRgeneration counter for struct se_device"
2146 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2147 		 * READ_KEYS service action.
2148 		 */
2149 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2150 		pr_reg->pr_res_key = sa_res_key;
2151 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2152 			 " Key for %s to: 0x%016Lx PRgeneration:"
2153 			 " 0x%08x\n", cmd->se_tfo->fabric_name,
2154 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2155 			 pr_reg->pr_reg_nacl->initiatorname,
2156 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2157 
2158 	} else {
2159 		/*
2160 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2161 		 */
2162 		type = pr_reg->pr_res_type;
2163 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2164 							      pr_reg);
2165 		if (pr_holder < 0) {
2166 			ret = TCM_RESERVATION_CONFLICT;
2167 			goto out;
2168 		}
2169 
2170 		spin_lock(&pr_tmpl->registration_lock);
2171 		/*
2172 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2173 		 * and matching pr_res_key.
2174 		 */
2175 		if (pr_reg->pr_reg_all_tg_pt) {
2176 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2177 					&pr_tmpl->registration_list,
2178 					pr_reg_list) {
2179 
2180 				if (!pr_reg_p->pr_reg_all_tg_pt)
2181 					continue;
2182 				if (pr_reg_p->pr_res_key != res_key)
2183 					continue;
2184 				if (pr_reg == pr_reg_p)
2185 					continue;
2186 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2187 					   pr_reg_p->pr_reg_nacl->initiatorname))
2188 					continue;
2189 
2190 				__core_scsi3_free_registration(dev,
2191 						pr_reg_p, NULL, 0);
2192 			}
2193 		}
2194 
2195 		/*
2196 		 * Release the calling I_T Nexus registration now..
2197 		 */
2198 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2199 		pr_reg = NULL;
2200 
2201 		/*
2202 		 * From spc4r17, section 5.7.11.3 Unregistering
2203 		 *
2204 		 * If the persistent reservation is a registrants only
2205 		 * type, the device server shall establish a unit
2206 		 * attention condition for the initiator port associated
2207 		 * with every registered I_T nexus except for the I_T
2208 		 * nexus on which the PERSISTENT RESERVE OUT command was
2209 		 * received, with the additional sense code set to
2210 		 * RESERVATIONS RELEASED.
2211 		 */
2212 		if (pr_holder &&
2213 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2214 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2215 			list_for_each_entry(pr_reg_p,
2216 					&pr_tmpl->registration_list,
2217 					pr_reg_list) {
2218 
2219 				target_ua_allocate_lun(
2220 					pr_reg_p->pr_reg_nacl,
2221 					pr_reg_p->pr_res_mapped_lun,
2222 					0x2A,
2223 					ASCQ_2AH_RESERVATIONS_RELEASED);
2224 			}
2225 		}
2226 
2227 		spin_unlock(&pr_tmpl->registration_lock);
2228 	}
2229 
2230 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2231 
2232 out:
2233 	if (pr_reg)
2234 		core_scsi3_put_pr_reg(pr_reg);
2235 	return ret;
2236 }
2237 
2238 unsigned char *core_scsi3_pr_dump_type(int type)
2239 {
2240 	switch (type) {
2241 	case PR_TYPE_WRITE_EXCLUSIVE:
2242 		return "Write Exclusive Access";
2243 	case PR_TYPE_EXCLUSIVE_ACCESS:
2244 		return "Exclusive Access";
2245 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2246 		return "Write Exclusive Access, Registrants Only";
2247 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2248 		return "Exclusive Access, Registrants Only";
2249 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2250 		return "Write Exclusive Access, All Registrants";
2251 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2252 		return "Exclusive Access, All Registrants";
2253 	default:
2254 		break;
2255 	}
2256 
2257 	return "Unknown SPC-3 PR Type";
2258 }
2259 
2260 static sense_reason_t
2261 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2262 {
2263 	struct se_device *dev = cmd->se_dev;
2264 	struct se_session *se_sess = cmd->se_sess;
2265 	struct se_lun *se_lun = cmd->se_lun;
2266 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2267 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2268 	char i_buf[PR_REG_ISID_ID_LEN] = { };
2269 	sense_reason_t ret;
2270 
2271 	if (!se_sess || !se_lun) {
2272 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2273 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2274 	}
2275 	/*
2276 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2277 	 */
2278 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2279 				se_sess);
2280 	if (!pr_reg) {
2281 		pr_err("SPC-3 PR: Unable to locate"
2282 			" PR_REGISTERED *pr_reg for RESERVE\n");
2283 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2284 	}
2285 	/*
2286 	 * From spc4r17 Section 5.7.9: Reserving:
2287 	 *
2288 	 * An application client creates a persistent reservation by issuing
2289 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2290 	 * a registered I_T nexus with the following parameters:
2291 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2292 	 * 	 registered with the logical unit for the I_T nexus; and
2293 	 */
2294 	if (res_key != pr_reg->pr_res_key) {
2295 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2296 			" does not match existing SA REGISTER res_key:"
2297 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2298 		ret = TCM_RESERVATION_CONFLICT;
2299 		goto out_put_pr_reg;
2300 	}
2301 	/*
2302 	 * From spc4r17 Section 5.7.9: Reserving:
2303 	 *
2304 	 * From above:
2305 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2306 	 *     being created.
2307 	 *
2308 	 * Only one persistent reservation is allowed at a time per logical unit
2309 	 * and that persistent reservation has a scope of LU_SCOPE.
2310 	 */
2311 	if (scope != PR_SCOPE_LU_SCOPE) {
2312 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2313 		ret = TCM_INVALID_PARAMETER_LIST;
2314 		goto out_put_pr_reg;
2315 	}
2316 	/*
2317 	 * See if we have an existing PR reservation holder pointer at
2318 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2319 	 * *pr_res_holder.
2320 	 */
2321 	spin_lock(&dev->dev_reservation_lock);
2322 	pr_res_holder = dev->dev_pr_res_holder;
2323 	if (pr_res_holder) {
2324 		/*
2325 		 * From spc4r17 Section 5.7.9: Reserving:
2326 		 *
2327 		 * If the device server receives a PERSISTENT RESERVE OUT
2328 		 * command from an I_T nexus other than a persistent reservation
2329 		 * holder (see 5.7.10) that attempts to create a persistent
2330 		 * reservation when a persistent reservation already exists for
2331 		 * the logical unit, then the command shall be completed with
2332 		 * RESERVATION CONFLICT status.
2333 		 */
2334 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2335 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2336 			pr_err("SPC-3 PR: Attempted RESERVE from"
2337 				" [%s]: %s while reservation already held by"
2338 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2339 				cmd->se_tfo->fabric_name,
2340 				se_sess->se_node_acl->initiatorname,
2341 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2342 				pr_res_holder->pr_reg_nacl->initiatorname);
2343 
2344 			spin_unlock(&dev->dev_reservation_lock);
2345 			ret = TCM_RESERVATION_CONFLICT;
2346 			goto out_put_pr_reg;
2347 		}
2348 		/*
2349 		 * From spc4r17 Section 5.7.9: Reserving:
2350 		 *
2351 		 * If a persistent reservation holder attempts to modify the
2352 		 * type or scope of an existing persistent reservation, the
2353 		 * command shall be completed with RESERVATION CONFLICT status.
2354 		 */
2355 		if ((pr_res_holder->pr_res_type != type) ||
2356 		    (pr_res_holder->pr_res_scope != scope)) {
2357 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2358 			pr_err("SPC-3 PR: Attempted RESERVE from"
2359 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2360 				" while reservation already held by [%s]: %s,"
2361 				" returning RESERVATION_CONFLICT\n",
2362 				cmd->se_tfo->fabric_name,
2363 				se_sess->se_node_acl->initiatorname,
2364 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2365 				pr_res_holder->pr_reg_nacl->initiatorname);
2366 
2367 			spin_unlock(&dev->dev_reservation_lock);
2368 			ret = TCM_RESERVATION_CONFLICT;
2369 			goto out_put_pr_reg;
2370 		}
2371 		/*
2372 		 * From spc4r17 Section 5.7.9: Reserving:
2373 		 *
2374 		 * If the device server receives a PERSISTENT RESERVE OUT
2375 		 * command with RESERVE service action where the TYPE field and
2376 		 * the SCOPE field contain the same values as the existing type
2377 		 * and scope from a persistent reservation holder, it shall not
2378 		 * make any change to the existing persistent reservation and
2379 		 * shall completethe command with GOOD status.
2380 		 */
2381 		spin_unlock(&dev->dev_reservation_lock);
2382 		ret = 0;
2383 		goto out_put_pr_reg;
2384 	}
2385 	/*
2386 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2387 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2388 	 */
2389 	pr_reg->pr_res_scope = scope;
2390 	pr_reg->pr_res_type = type;
2391 	pr_reg->pr_res_holder = 1;
2392 	dev->dev_pr_res_holder = pr_reg;
2393 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2394 
2395 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2396 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2397 		cmd->se_tfo->fabric_name, core_scsi3_pr_dump_type(type),
2398 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2399 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2400 			cmd->se_tfo->fabric_name,
2401 			se_sess->se_node_acl->initiatorname,
2402 			i_buf);
2403 	spin_unlock(&dev->dev_reservation_lock);
2404 
2405 	if (pr_tmpl->pr_aptpl_active)
2406 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2407 
2408 	ret = 0;
2409 out_put_pr_reg:
2410 	core_scsi3_put_pr_reg(pr_reg);
2411 	return ret;
2412 }
2413 
2414 static sense_reason_t
2415 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2416 		u64 res_key)
2417 {
2418 	switch (type) {
2419 	case PR_TYPE_WRITE_EXCLUSIVE:
2420 	case PR_TYPE_EXCLUSIVE_ACCESS:
2421 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2422 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2423 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2424 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2425 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2426 	default:
2427 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2428 			" 0x%02x\n", type);
2429 		return TCM_INVALID_CDB_FIELD;
2430 	}
2431 }
2432 
2433 static void __core_scsi3_complete_pro_release(
2434 	struct se_device *dev,
2435 	struct se_node_acl *se_nacl,
2436 	struct t10_pr_registration *pr_reg,
2437 	int explicit,
2438 	int unreg)
2439 {
2440 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2441 	char i_buf[PR_REG_ISID_ID_LEN] = { };
2442 	int pr_res_type = 0, pr_res_scope = 0;
2443 
2444 	lockdep_assert_held(&dev->dev_reservation_lock);
2445 
2446 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2447 	/*
2448 	 * Go ahead and release the current PR reservation holder.
2449 	 * If an All Registrants reservation is currently active and
2450 	 * a unregister operation is requested, replace the current
2451 	 * dev_pr_res_holder with another active registration.
2452 	 */
2453 	if (dev->dev_pr_res_holder) {
2454 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2455 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2456 		dev->dev_pr_res_holder->pr_res_type = 0;
2457 		dev->dev_pr_res_holder->pr_res_scope = 0;
2458 		dev->dev_pr_res_holder->pr_res_holder = 0;
2459 		dev->dev_pr_res_holder = NULL;
2460 	}
2461 	if (!unreg)
2462 		goto out;
2463 
2464 	spin_lock(&dev->t10_pr.registration_lock);
2465 	list_del_init(&pr_reg->pr_reg_list);
2466 	/*
2467 	 * If the I_T nexus is a reservation holder, the persistent reservation
2468 	 * is of an all registrants type, and the I_T nexus is the last remaining
2469 	 * registered I_T nexus, then the device server shall also release the
2470 	 * persistent reservation.
2471 	 */
2472 	if (!list_empty(&dev->t10_pr.registration_list) &&
2473 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2474 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2475 		dev->dev_pr_res_holder =
2476 			list_entry(dev->t10_pr.registration_list.next,
2477 				   struct t10_pr_registration, pr_reg_list);
2478 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2479 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2480 		dev->dev_pr_res_holder->pr_res_holder = 1;
2481 	}
2482 	spin_unlock(&dev->t10_pr.registration_lock);
2483 out:
2484 	if (!dev->dev_pr_res_holder) {
2485 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2486 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2487 			tfo->fabric_name, (explicit) ? "explicit" :
2488 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2489 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2490 	}
2491 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2492 		tfo->fabric_name, se_nacl->initiatorname,
2493 		i_buf);
2494 	/*
2495 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2496 	 */
2497 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2498 }
2499 
2500 static sense_reason_t
2501 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2502 		u64 res_key)
2503 {
2504 	struct se_device *dev = cmd->se_dev;
2505 	struct se_session *se_sess = cmd->se_sess;
2506 	struct se_lun *se_lun = cmd->se_lun;
2507 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2508 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2509 	sense_reason_t ret = 0;
2510 
2511 	if (!se_sess || !se_lun) {
2512 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2513 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2514 	}
2515 	/*
2516 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2517 	 */
2518 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2519 	if (!pr_reg) {
2520 		pr_err("SPC-3 PR: Unable to locate"
2521 			" PR_REGISTERED *pr_reg for RELEASE\n");
2522 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2523 	}
2524 	/*
2525 	 * From spc4r17 Section 5.7.11.2 Releasing:
2526 	 *
2527 	 * If there is no persistent reservation or in response to a persistent
2528 	 * reservation release request from a registered I_T nexus that is not a
2529 	 * persistent reservation holder (see 5.7.10), the device server shall
2530 	 * do the following:
2531 	 *
2532 	 *     a) Not release the persistent reservation, if any;
2533 	 *     b) Not remove any registrations; and
2534 	 *     c) Complete the command with GOOD status.
2535 	 */
2536 	spin_lock(&dev->dev_reservation_lock);
2537 	pr_res_holder = dev->dev_pr_res_holder;
2538 	if (!pr_res_holder) {
2539 		/*
2540 		 * No persistent reservation, return GOOD status.
2541 		 */
2542 		spin_unlock(&dev->dev_reservation_lock);
2543 		goto out_put_pr_reg;
2544 	}
2545 
2546 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2547 		/*
2548 		 * Release request from a registered I_T nexus that is not a
2549 		 * persistent reservation holder. return GOOD status.
2550 		 */
2551 		spin_unlock(&dev->dev_reservation_lock);
2552 		goto out_put_pr_reg;
2553 	}
2554 
2555 	/*
2556 	 * From spc4r17 Section 5.7.11.2 Releasing:
2557 	 *
2558 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2559 	 * release a persistent reservation.
2560 	 *
2561 	 * An application client releases the persistent reservation by issuing
2562 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2563 	 * an I_T nexus that is a persistent reservation holder with the
2564 	 * following parameters:
2565 	 *
2566 	 *     a) RESERVATION KEY field set to the value of the reservation key
2567 	 *	  that is registered with the logical unit for the I_T nexus;
2568 	 */
2569 	if (res_key != pr_reg->pr_res_key) {
2570 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2571 			" does not match existing SA REGISTER res_key:"
2572 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2573 		spin_unlock(&dev->dev_reservation_lock);
2574 		ret = TCM_RESERVATION_CONFLICT;
2575 		goto out_put_pr_reg;
2576 	}
2577 	/*
2578 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2579 	 *
2580 	 * b) TYPE field and SCOPE field set to match the persistent
2581 	 *    reservation being released.
2582 	 */
2583 	if ((pr_res_holder->pr_res_type != type) ||
2584 	    (pr_res_holder->pr_res_scope != scope)) {
2585 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2586 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2587 			" reservation from [%s]: %s with different TYPE "
2588 			"and/or SCOPE  while reservation already held by"
2589 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2590 			cmd->se_tfo->fabric_name,
2591 			se_sess->se_node_acl->initiatorname,
2592 			pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2593 			pr_res_holder->pr_reg_nacl->initiatorname);
2594 
2595 		spin_unlock(&dev->dev_reservation_lock);
2596 		ret = TCM_RESERVATION_CONFLICT;
2597 		goto out_put_pr_reg;
2598 	}
2599 	/*
2600 	 * In response to a persistent reservation release request from the
2601 	 * persistent reservation holder the device server shall perform a
2602 	 * release by doing the following as an uninterrupted series of actions:
2603 	 * a) Release the persistent reservation;
2604 	 * b) Not remove any registration(s);
2605 	 * c) If the released persistent reservation is a registrants only type
2606 	 * or all registrants type persistent reservation,
2607 	 *    the device server shall establish a unit attention condition for
2608 	 *    the initiator port associated with every regis-
2609 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2610 	 *    RESERVE OUT command with RELEASE service action was received,
2611 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2612 	 * d) If the persistent reservation is of any other type, the device
2613 	 *    server shall not establish a unit attention condition.
2614 	 */
2615 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2616 					  pr_reg, 1, 0);
2617 
2618 	spin_unlock(&dev->dev_reservation_lock);
2619 
2620 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2621 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2622 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2623 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2624 		/*
2625 		 * If no UNIT ATTENTION conditions will be established for
2626 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2627 		 * go ahead and check for APTPL=1 update+write below
2628 		 */
2629 		goto write_aptpl;
2630 	}
2631 
2632 	spin_lock(&pr_tmpl->registration_lock);
2633 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2634 			pr_reg_list) {
2635 		/*
2636 		 * Do not establish a UNIT ATTENTION condition
2637 		 * for the calling I_T Nexus
2638 		 */
2639 		if (pr_reg_p == pr_reg)
2640 			continue;
2641 
2642 		target_ua_allocate_lun(pr_reg_p->pr_reg_nacl,
2643 				pr_reg_p->pr_res_mapped_lun,
2644 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2645 	}
2646 	spin_unlock(&pr_tmpl->registration_lock);
2647 
2648 write_aptpl:
2649 	if (pr_tmpl->pr_aptpl_active)
2650 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2651 
2652 out_put_pr_reg:
2653 	core_scsi3_put_pr_reg(pr_reg);
2654 	return ret;
2655 }
2656 
2657 static sense_reason_t
2658 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2659 {
2660 	struct se_device *dev = cmd->se_dev;
2661 	struct se_node_acl *pr_reg_nacl;
2662 	struct se_session *se_sess = cmd->se_sess;
2663 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2664 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2665 	u64 pr_res_mapped_lun = 0;
2666 	int calling_it_nexus = 0;
2667 	/*
2668 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2669 	 */
2670 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2671 			se_sess->se_node_acl, se_sess);
2672 	if (!pr_reg_n) {
2673 		pr_err("SPC-3 PR: Unable to locate"
2674 			" PR_REGISTERED *pr_reg for CLEAR\n");
2675 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2676 	}
2677 	/*
2678 	 * From spc4r17 section 5.7.11.6, Clearing:
2679 	 *
2680 	 * Any application client may release the persistent reservation and
2681 	 * remove all registrations from a device server by issuing a
2682 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2683 	 * registered I_T nexus with the following parameter:
2684 	 *
2685 	 *	a) RESERVATION KEY field set to the value of the reservation key
2686 	 * 	   that is registered with the logical unit for the I_T nexus.
2687 	 */
2688 	if (res_key != pr_reg_n->pr_res_key) {
2689 		pr_err("SPC-3 PR REGISTER: Received"
2690 			" res_key: 0x%016Lx does not match"
2691 			" existing SA REGISTER res_key:"
2692 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2693 		core_scsi3_put_pr_reg(pr_reg_n);
2694 		return TCM_RESERVATION_CONFLICT;
2695 	}
2696 	/*
2697 	 * a) Release the persistent reservation, if any;
2698 	 */
2699 	spin_lock(&dev->dev_reservation_lock);
2700 	pr_res_holder = dev->dev_pr_res_holder;
2701 	if (pr_res_holder) {
2702 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2703 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2704 						  pr_res_holder, 0, 0);
2705 	}
2706 	spin_unlock(&dev->dev_reservation_lock);
2707 	/*
2708 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2709 	 */
2710 	spin_lock(&pr_tmpl->registration_lock);
2711 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2712 			&pr_tmpl->registration_list, pr_reg_list) {
2713 
2714 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2715 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2716 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2717 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2718 					calling_it_nexus);
2719 		/*
2720 		 * e) Establish a unit attention condition for the initiator
2721 		 *    port associated with every registered I_T nexus other
2722 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2723 		 *    command with CLEAR service action was received, with the
2724 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2725 		 */
2726 		if (!calling_it_nexus)
2727 			target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun,
2728 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2729 	}
2730 	spin_unlock(&pr_tmpl->registration_lock);
2731 
2732 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2733 		cmd->se_tfo->fabric_name);
2734 
2735 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2736 
2737 	core_scsi3_pr_generation(dev);
2738 	return 0;
2739 }
2740 
2741 static void __core_scsi3_complete_pro_preempt(
2742 	struct se_device *dev,
2743 	struct t10_pr_registration *pr_reg,
2744 	struct list_head *preempt_and_abort_list,
2745 	int type,
2746 	int scope,
2747 	enum preempt_type preempt_type)
2748 {
2749 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2750 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2751 	char i_buf[PR_REG_ISID_ID_LEN] = { };
2752 
2753 	lockdep_assert_held(&dev->dev_reservation_lock);
2754 
2755 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2756 	/*
2757 	 * Do an implicit RELEASE of the existing reservation.
2758 	 */
2759 	if (dev->dev_pr_res_holder)
2760 		__core_scsi3_complete_pro_release(dev, nacl,
2761 						  dev->dev_pr_res_holder, 0, 0);
2762 
2763 	dev->dev_pr_res_holder = pr_reg;
2764 	pr_reg->pr_res_holder = 1;
2765 	pr_reg->pr_res_type = type;
2766 	pr_reg->pr_res_scope = scope;
2767 
2768 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2769 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2770 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2771 		core_scsi3_pr_dump_type(type),
2772 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2773 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2774 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2775 		nacl->initiatorname, i_buf);
2776 	/*
2777 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2778 	 * struct t10_pr_registration to the list that will be compared
2779 	 * against received CDBs..
2780 	 */
2781 	if (preempt_and_abort_list)
2782 		list_add_tail(&pr_reg->pr_reg_abort_list,
2783 				preempt_and_abort_list);
2784 }
2785 
2786 static void core_scsi3_release_preempt_and_abort(
2787 	struct list_head *preempt_and_abort_list,
2788 	struct t10_pr_registration *pr_reg_holder)
2789 {
2790 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2791 
2792 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2793 				pr_reg_abort_list) {
2794 
2795 		list_del(&pr_reg->pr_reg_abort_list);
2796 		if (pr_reg_holder == pr_reg)
2797 			continue;
2798 		if (pr_reg->pr_res_holder) {
2799 			pr_warn("pr_reg->pr_res_holder still set\n");
2800 			continue;
2801 		}
2802 
2803 		pr_reg->pr_reg_deve = NULL;
2804 		pr_reg->pr_reg_nacl = NULL;
2805 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2806 	}
2807 }
2808 
2809 static sense_reason_t
2810 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2811 		u64 sa_res_key, enum preempt_type preempt_type)
2812 {
2813 	struct se_device *dev = cmd->se_dev;
2814 	struct se_node_acl *pr_reg_nacl;
2815 	struct se_session *se_sess = cmd->se_sess;
2816 	LIST_HEAD(preempt_and_abort_list);
2817 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2818 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2819 	u64 pr_res_mapped_lun = 0;
2820 	int all_reg = 0, calling_it_nexus = 0;
2821 	bool sa_res_key_unmatched = sa_res_key != 0;
2822 	int prh_type = 0, prh_scope = 0;
2823 
2824 	if (!se_sess)
2825 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2826 
2827 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2828 				se_sess);
2829 	if (!pr_reg_n) {
2830 		pr_err("SPC-3 PR: Unable to locate"
2831 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2832 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2833 		return TCM_RESERVATION_CONFLICT;
2834 	}
2835 	if (pr_reg_n->pr_res_key != res_key) {
2836 		core_scsi3_put_pr_reg(pr_reg_n);
2837 		return TCM_RESERVATION_CONFLICT;
2838 	}
2839 	if (scope != PR_SCOPE_LU_SCOPE) {
2840 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2841 		core_scsi3_put_pr_reg(pr_reg_n);
2842 		return TCM_INVALID_PARAMETER_LIST;
2843 	}
2844 
2845 	spin_lock(&dev->dev_reservation_lock);
2846 	pr_res_holder = dev->dev_pr_res_holder;
2847 	if (pr_res_holder &&
2848 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2849 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2850 		all_reg = 1;
2851 
2852 	if (!all_reg && !sa_res_key) {
2853 		spin_unlock(&dev->dev_reservation_lock);
2854 		core_scsi3_put_pr_reg(pr_reg_n);
2855 		return TCM_INVALID_PARAMETER_LIST;
2856 	}
2857 	/*
2858 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2859 	 *
2860 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2861 	 * persistent reservation holder or there is no persistent reservation
2862 	 * holder (i.e., there is no persistent reservation), then the device
2863 	 * server shall perform a preempt by doing the following in an
2864 	 * uninterrupted series of actions. (See below..)
2865 	 */
2866 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2867 		/*
2868 		 * No existing or SA Reservation Key matching reservations..
2869 		 *
2870 		 * PROUT SA PREEMPT with All Registrant type reservations are
2871 		 * allowed to be processed without a matching SA Reservation Key
2872 		 */
2873 		spin_lock(&pr_tmpl->registration_lock);
2874 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2875 				&pr_tmpl->registration_list, pr_reg_list) {
2876 			/*
2877 			 * Removing of registrations in non all registrants
2878 			 * type reservations without a matching SA reservation
2879 			 * key.
2880 			 *
2881 			 * a) Remove the registrations for all I_T nexuses
2882 			 *    specified by the SERVICE ACTION RESERVATION KEY
2883 			 *    field;
2884 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2885 			 * c) Process tasks as defined in 5.7.1; and
2886 			 * d) Establish a unit attention condition for the
2887 			 *    initiator port associated with every I_T nexus
2888 			 *    that lost its registration other than the I_T
2889 			 *    nexus on which the PERSISTENT RESERVE OUT command
2890 			 *    was received, with the additional sense code set
2891 			 *    to REGISTRATIONS PREEMPTED.
2892 			 */
2893 			if (!all_reg) {
2894 				if (pr_reg->pr_res_key != sa_res_key)
2895 					continue;
2896 				sa_res_key_unmatched = false;
2897 
2898 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2899 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2900 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2901 				__core_scsi3_free_registration(dev, pr_reg,
2902 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2903 						NULL, calling_it_nexus);
2904 			} else {
2905 				/*
2906 				 * Case for any existing all registrants type
2907 				 * reservation, follow logic in spc4r17 section
2908 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2909 				 *
2910 				 * For a ZERO SA Reservation key, release
2911 				 * all other registrations and do an implicit
2912 				 * release of active persistent reservation.
2913 				 *
2914 				 * For a non-ZERO SA Reservation key, only
2915 				 * release the matching reservation key from
2916 				 * registrations.
2917 				 */
2918 				if ((sa_res_key) &&
2919 				     (pr_reg->pr_res_key != sa_res_key))
2920 					continue;
2921 				sa_res_key_unmatched = false;
2922 
2923 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2924 				if (calling_it_nexus)
2925 					continue;
2926 
2927 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2928 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2929 				__core_scsi3_free_registration(dev, pr_reg,
2930 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2931 						NULL, 0);
2932 			}
2933 			if (!calling_it_nexus)
2934 				target_ua_allocate_lun(pr_reg_nacl,
2935 					pr_res_mapped_lun, 0x2A,
2936 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2937 		}
2938 		spin_unlock(&pr_tmpl->registration_lock);
2939 		/*
2940 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2941 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2942 		 * RESERVATION KEY field to a value that does not match any
2943 		 * registered reservation key, then the device server shall
2944 		 * complete the command with RESERVATION CONFLICT status.
2945 		 */
2946 		if (sa_res_key_unmatched) {
2947 			spin_unlock(&dev->dev_reservation_lock);
2948 			core_scsi3_put_pr_reg(pr_reg_n);
2949 			return TCM_RESERVATION_CONFLICT;
2950 		}
2951 		/*
2952 		 * For an existing all registrants type reservation
2953 		 * with a zero SA rservation key, preempt the existing
2954 		 * reservation with the new PR type and scope.
2955 		 */
2956 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2957 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2958 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2959 				type, scope, preempt_type);
2960 		}
2961 
2962 		spin_unlock(&dev->dev_reservation_lock);
2963 
2964 		/*
2965 		 * SPC-4 5.12.11.2.6 Preempting and aborting
2966 		 * The actions described in this subclause shall be performed
2967 		 * for all I_T nexuses that are registered with the non-zero
2968 		 * SERVICE ACTION RESERVATION KEY value, without regard for
2969 		 * whether the preempted I_T nexuses hold the persistent
2970 		 * reservation. If the SERVICE ACTION RESERVATION KEY field is
2971 		 * set to zero and an all registrants persistent reservation is
2972 		 * present, the device server shall abort all commands for all
2973 		 * registered I_T nexuses.
2974 		 */
2975 		if (preempt_type == PREEMPT_AND_ABORT) {
2976 			core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list,
2977 					   cmd);
2978 			core_scsi3_release_preempt_and_abort(
2979 				&preempt_and_abort_list, pr_reg_n);
2980 		}
2981 
2982 		if (pr_tmpl->pr_aptpl_active)
2983 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2984 
2985 		core_scsi3_put_pr_reg(pr_reg_n);
2986 		core_scsi3_pr_generation(cmd->se_dev);
2987 		return 0;
2988 	}
2989 	/*
2990 	 * The PREEMPTing SA reservation key matches that of the
2991 	 * existing persistent reservation, first, we check if
2992 	 * we are preempting our own reservation.
2993 	 * From spc4r17, section 5.7.11.4.3 Preempting
2994 	 * persistent reservations and registration handling
2995 	 *
2996 	 * If an all registrants persistent reservation is not
2997 	 * present, it is not an error for the persistent
2998 	 * reservation holder to preempt itself (i.e., a
2999 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3000 	 * or a PREEMPT AND ABORT service action with the
3001 	 * SERVICE ACTION RESERVATION KEY value equal to the
3002 	 * persistent reservation holder's reservation key that
3003 	 * is received from the persistent reservation holder).
3004 	 * In that case, the device server shall establish the
3005 	 * new persistent reservation and maintain the
3006 	 * registration.
3007 	 */
3008 	prh_type = pr_res_holder->pr_res_type;
3009 	prh_scope = pr_res_holder->pr_res_scope;
3010 	/*
3011 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3012 	 * persistent reservation holder (see 5.7.10), the device
3013 	 * server shall perform a preempt by doing the following as
3014 	 * an uninterrupted series of actions:
3015 	 *
3016 	 * a) Release the persistent reservation for the holder
3017 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3018 	 */
3019 	if (pr_reg_n != pr_res_holder)
3020 		__core_scsi3_complete_pro_release(dev,
3021 						  pr_res_holder->pr_reg_nacl,
3022 						  dev->dev_pr_res_holder, 0, 0);
3023 	/*
3024 	 * b) Remove the registrations for all I_T nexuses identified
3025 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3026 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3027 	 *    OUT command. If an all registrants persistent reservation
3028 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3029 	 *    is set to zero, then all registrations shall be removed
3030 	 *    except for that of the I_T nexus that is being used for
3031 	 *    the PERSISTENT RESERVE OUT command;
3032 	 */
3033 	spin_lock(&pr_tmpl->registration_lock);
3034 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3035 			&pr_tmpl->registration_list, pr_reg_list) {
3036 
3037 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3038 		if (calling_it_nexus)
3039 			continue;
3040 
3041 		if (sa_res_key && pr_reg->pr_res_key != sa_res_key)
3042 			continue;
3043 
3044 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3045 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3046 		__core_scsi3_free_registration(dev, pr_reg,
3047 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3048 				calling_it_nexus);
3049 		/*
3050 		 * e) Establish a unit attention condition for the initiator
3051 		 *    port associated with every I_T nexus that lost its
3052 		 *    persistent reservation and/or registration, with the
3053 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3054 		 */
3055 		target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3056 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3057 	}
3058 	spin_unlock(&pr_tmpl->registration_lock);
3059 	/*
3060 	 * c) Establish a persistent reservation for the preempting
3061 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3062 	 */
3063 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3064 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3065 			type, scope, preempt_type);
3066 	/*
3067 	 * d) Process tasks as defined in 5.7.1;
3068 	 * e) See above..
3069 	 * f) If the type or scope has changed, then for every I_T nexus
3070 	 *    whose reservation key was not removed, except for the I_T
3071 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3072 	 *    received, the device server shall establish a unit
3073 	 *    attention condition for the initiator port associated with
3074 	 *    that I_T nexus, with the additional sense code set to
3075 	 *    RESERVATIONS RELEASED. If the type or scope have not
3076 	 *    changed, then no unit attention condition(s) shall be
3077 	 *    established for this reason.
3078 	 */
3079 	if ((prh_type != type) || (prh_scope != scope)) {
3080 		spin_lock(&pr_tmpl->registration_lock);
3081 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3082 				&pr_tmpl->registration_list, pr_reg_list) {
3083 
3084 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3085 			if (calling_it_nexus)
3086 				continue;
3087 
3088 			target_ua_allocate_lun(pr_reg->pr_reg_nacl,
3089 					pr_reg->pr_res_mapped_lun, 0x2A,
3090 					ASCQ_2AH_RESERVATIONS_RELEASED);
3091 		}
3092 		spin_unlock(&pr_tmpl->registration_lock);
3093 	}
3094 	spin_unlock(&dev->dev_reservation_lock);
3095 	/*
3096 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3097 	 * All received CDBs for the matching existing reservation and
3098 	 * registrations undergo ABORT_TASK logic.
3099 	 *
3100 	 * From there, core_scsi3_release_preempt_and_abort() will
3101 	 * release every registration in the list (which have already
3102 	 * been removed from the primary pr_reg list), except the
3103 	 * new persistent reservation holder, the calling Initiator Port.
3104 	 */
3105 	if (preempt_type == PREEMPT_AND_ABORT) {
3106 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3107 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3108 						pr_reg_n);
3109 	}
3110 
3111 	if (pr_tmpl->pr_aptpl_active)
3112 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3113 
3114 	core_scsi3_put_pr_reg(pr_reg_n);
3115 	core_scsi3_pr_generation(cmd->se_dev);
3116 	return 0;
3117 }
3118 
3119 static sense_reason_t
3120 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3121 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3122 {
3123 	switch (type) {
3124 	case PR_TYPE_WRITE_EXCLUSIVE:
3125 	case PR_TYPE_EXCLUSIVE_ACCESS:
3126 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3127 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3128 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3129 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3130 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3131 					      sa_res_key, preempt_type);
3132 	default:
3133 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3134 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3135 		return TCM_INVALID_CDB_FIELD;
3136 	}
3137 }
3138 
3139 
3140 static sense_reason_t
3141 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3142 		u64 sa_res_key, int aptpl, int unreg)
3143 {
3144 	struct se_session *se_sess = cmd->se_sess;
3145 	struct se_device *dev = cmd->se_dev;
3146 	struct se_dev_entry *dest_se_deve = NULL;
3147 	struct se_lun *se_lun = cmd->se_lun, *tmp_lun;
3148 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3149 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3150 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3151 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3152 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3153 	unsigned char *buf;
3154 	const unsigned char *initiator_str;
3155 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN] = { };
3156 	u32 tid_len, tmp_tid_len;
3157 	int new_reg = 0, type, scope, matching_iname;
3158 	sense_reason_t ret;
3159 	unsigned short rtpi;
3160 	unsigned char proto_ident;
3161 
3162 	if (!se_sess || !se_lun) {
3163 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3164 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3165 	}
3166 
3167 	se_tpg = se_sess->se_tpg;
3168 	tf_ops = se_tpg->se_tpg_tfo;
3169 	/*
3170 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3171 	 *	Register behaviors for a REGISTER AND MOVE service action
3172 	 *
3173 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3174 	 */
3175 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3176 				se_sess);
3177 	if (!pr_reg) {
3178 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3179 			" *pr_reg for REGISTER_AND_MOVE\n");
3180 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3181 	}
3182 	/*
3183 	 * The provided reservation key much match the existing reservation key
3184 	 * provided during this initiator's I_T nexus registration.
3185 	 */
3186 	if (res_key != pr_reg->pr_res_key) {
3187 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3188 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3189 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3190 		ret = TCM_RESERVATION_CONFLICT;
3191 		goto out_put_pr_reg;
3192 	}
3193 	/*
3194 	 * The service active reservation key needs to be non zero
3195 	 */
3196 	if (!sa_res_key) {
3197 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3198 			" sa_res_key\n");
3199 		ret = TCM_INVALID_PARAMETER_LIST;
3200 		goto out_put_pr_reg;
3201 	}
3202 
3203 	/*
3204 	 * Determine the Relative Target Port Identifier where the reservation
3205 	 * will be moved to for the TransportID containing SCSI initiator WWN
3206 	 * information.
3207 	 */
3208 	buf = transport_kmap_data_sg(cmd);
3209 	if (!buf) {
3210 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3211 		goto out_put_pr_reg;
3212 	}
3213 
3214 	rtpi = get_unaligned_be16(&buf[18]);
3215 	tid_len = get_unaligned_be32(&buf[20]);
3216 	transport_kunmap_data_sg(cmd);
3217 	buf = NULL;
3218 
3219 	if ((tid_len + 24) != cmd->data_length) {
3220 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3221 			" does not equal CDB data_length: %u\n", tid_len,
3222 			cmd->data_length);
3223 		ret = TCM_INVALID_PARAMETER_LIST;
3224 		goto out_put_pr_reg;
3225 	}
3226 
3227 	spin_lock(&dev->se_port_lock);
3228 	list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
3229 		if (tmp_lun->lun_tpg->tpg_rtpi != rtpi)
3230 			continue;
3231 		dest_se_tpg = tmp_lun->lun_tpg;
3232 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3233 		if (!dest_tf_ops)
3234 			continue;
3235 
3236 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3237 		spin_unlock(&dev->se_port_lock);
3238 
3239 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3240 			pr_err("core_scsi3_tpg_depend_item() failed"
3241 				" for dest_se_tpg\n");
3242 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3243 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3244 			goto out_put_pr_reg;
3245 		}
3246 
3247 		spin_lock(&dev->se_port_lock);
3248 		break;
3249 	}
3250 	spin_unlock(&dev->se_port_lock);
3251 
3252 	if (!dest_se_tpg || !dest_tf_ops) {
3253 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3254 			" fabric ops from Relative Target Port Identifier:"
3255 			" %hu\n", rtpi);
3256 		ret = TCM_INVALID_PARAMETER_LIST;
3257 		goto out_put_pr_reg;
3258 	}
3259 
3260 	buf = transport_kmap_data_sg(cmd);
3261 	if (!buf) {
3262 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3263 		goto out_put_pr_reg;
3264 	}
3265 	proto_ident = (buf[24] & 0x0f);
3266 
3267 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3268 			" 0x%02x\n", proto_ident);
3269 
3270 	if (proto_ident != dest_se_tpg->proto_id) {
3271 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3272 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3273 			" from fabric: %s\n", proto_ident,
3274 			dest_se_tpg->proto_id,
3275 			dest_tf_ops->fabric_name);
3276 		ret = TCM_INVALID_PARAMETER_LIST;
3277 		goto out;
3278 	}
3279 	initiator_str = target_parse_pr_out_transport_id(dest_se_tpg,
3280 			&buf[24], &tmp_tid_len, &iport_ptr);
3281 	if (!initiator_str) {
3282 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3283 			" initiator_str from Transport ID\n");
3284 		ret = TCM_INVALID_PARAMETER_LIST;
3285 		goto out;
3286 	}
3287 
3288 	transport_kunmap_data_sg(cmd);
3289 	buf = NULL;
3290 
3291 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3292 		" %s\n", dest_tf_ops->fabric_name, (iport_ptr != NULL) ?
3293 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3294 		iport_ptr : "");
3295 	/*
3296 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3297 	 * action specifies a TransportID that is the same as the initiator port
3298 	 * of the I_T nexus for the command received, then the command shall
3299 	 * be terminated with CHECK CONDITION status, with the sense key set to
3300 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3301 	 * IN PARAMETER LIST.
3302 	 */
3303 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3304 	matching_iname = (!strcmp(initiator_str,
3305 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3306 	if (!matching_iname)
3307 		goto after_iport_check;
3308 
3309 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3310 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3311 			" matches: %s on received I_T Nexus\n", initiator_str,
3312 			pr_reg_nacl->initiatorname);
3313 		ret = TCM_INVALID_PARAMETER_LIST;
3314 		goto out;
3315 	}
3316 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3317 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3318 			" matches: %s %s on received I_T Nexus\n",
3319 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3320 			pr_reg->pr_reg_isid);
3321 		ret = TCM_INVALID_PARAMETER_LIST;
3322 		goto out;
3323 	}
3324 after_iport_check:
3325 	/*
3326 	 * Locate the destination struct se_node_acl from the received Transport ID
3327 	 */
3328 	mutex_lock(&dest_se_tpg->acl_node_mutex);
3329 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3330 				initiator_str);
3331 	if (dest_node_acl)
3332 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3333 	mutex_unlock(&dest_se_tpg->acl_node_mutex);
3334 
3335 	if (!dest_node_acl) {
3336 		pr_err("Unable to locate %s dest_node_acl for"
3337 			" TransportID%s\n", dest_tf_ops->fabric_name,
3338 			initiator_str);
3339 		ret = TCM_INVALID_PARAMETER_LIST;
3340 		goto out;
3341 	}
3342 
3343 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3344 		pr_err("core_scsi3_nodeacl_depend_item() for"
3345 			" dest_node_acl\n");
3346 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3347 		dest_node_acl = NULL;
3348 		ret = TCM_INVALID_PARAMETER_LIST;
3349 		goto out;
3350 	}
3351 
3352 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3353 		" %s from TransportID\n", dest_tf_ops->fabric_name,
3354 		dest_node_acl->initiatorname);
3355 
3356 	/*
3357 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3358 	 * PORT IDENTIFIER.
3359 	 */
3360 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3361 	if (!dest_se_deve) {
3362 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3363 			" %hu\n",  dest_tf_ops->fabric_name, rtpi);
3364 		ret = TCM_INVALID_PARAMETER_LIST;
3365 		goto out;
3366 	}
3367 
3368 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3369 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3370 		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
3371 		dest_se_deve = NULL;
3372 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3373 		goto out;
3374 	}
3375 
3376 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3377 		" ACL for dest_se_deve->mapped_lun: %llu\n",
3378 		dest_tf_ops->fabric_name, dest_node_acl->initiatorname,
3379 		dest_se_deve->mapped_lun);
3380 
3381 	/*
3382 	 * A persistent reservation needs to already existing in order to
3383 	 * successfully complete the REGISTER_AND_MOVE service action..
3384 	 */
3385 	spin_lock(&dev->dev_reservation_lock);
3386 	pr_res_holder = dev->dev_pr_res_holder;
3387 	if (!pr_res_holder) {
3388 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3389 			" currently held\n");
3390 		spin_unlock(&dev->dev_reservation_lock);
3391 		ret = TCM_INVALID_CDB_FIELD;
3392 		goto out;
3393 	}
3394 	/*
3395 	 * The received on I_T Nexus must be the reservation holder.
3396 	 *
3397 	 * From spc4r17 section 5.7.8  Table 50 --
3398 	 * 	Register behaviors for a REGISTER AND MOVE service action
3399 	 */
3400 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3401 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3402 			" Nexus is not reservation holder\n");
3403 		spin_unlock(&dev->dev_reservation_lock);
3404 		ret = TCM_RESERVATION_CONFLICT;
3405 		goto out;
3406 	}
3407 	/*
3408 	 * From spc4r17 section 5.7.8: registering and moving reservation
3409 	 *
3410 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3411 	 * action is received and the established persistent reservation is a
3412 	 * Write Exclusive - All Registrants type or Exclusive Access -
3413 	 * All Registrants type reservation, then the command shall be completed
3414 	 * with RESERVATION CONFLICT status.
3415 	 */
3416 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3417 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3418 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3419 			" reservation for type: %s\n",
3420 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3421 		spin_unlock(&dev->dev_reservation_lock);
3422 		ret = TCM_RESERVATION_CONFLICT;
3423 		goto out;
3424 	}
3425 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3426 	/*
3427 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3428 	 */
3429 	type = pr_res_holder->pr_res_type;
3430 	scope = pr_res_holder->pr_res_type;
3431 	/*
3432 	 * c) Associate the reservation key specified in the SERVICE ACTION
3433 	 *    RESERVATION KEY field with the I_T nexus specified as the
3434 	 *    destination of the register and move, where:
3435 	 *    A) The I_T nexus is specified by the TransportID and the
3436 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3437 	 *    B) Regardless of the TransportID format used, the association for
3438 	 *       the initiator port is based on either the initiator port name
3439 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3440 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3441 	 *       transport protocols where port names are not required;
3442 	 * d) Register the reservation key specified in the SERVICE ACTION
3443 	 *    RESERVATION KEY field;
3444 	 *
3445 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3446 	 * register an I_T nexus that is already registered with the same
3447 	 * reservation key or a different reservation key.
3448 	 */
3449 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3450 					iport_ptr);
3451 	if (!dest_pr_reg) {
3452 		struct se_lun *dest_lun = dest_se_deve->se_lun;
3453 
3454 		spin_unlock(&dev->dev_reservation_lock);
3455 		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
3456 					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
3457 					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
3458 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3459 			goto out;
3460 		}
3461 		spin_lock(&dev->dev_reservation_lock);
3462 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3463 						iport_ptr);
3464 		new_reg = 1;
3465 	} else {
3466 		/*
3467 		 * e) Retain the reservation key specified in the SERVICE ACTION
3468 		 *    RESERVATION KEY field and associated information;
3469 		 */
3470 		dest_pr_reg->pr_res_key = sa_res_key;
3471 	}
3472 	/*
3473 	 * f) Release the persistent reservation for the persistent reservation
3474 	 *    holder (i.e., the I_T nexus on which the
3475 	 */
3476 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3477 					  dev->dev_pr_res_holder, 0, 0);
3478 	/*
3479 	 * g) Move the persistent reservation to the specified I_T nexus using
3480 	 *    the same scope and type as the persistent reservation released in
3481 	 *    item f); and
3482 	 */
3483 	dev->dev_pr_res_holder = dest_pr_reg;
3484 	dest_pr_reg->pr_res_holder = 1;
3485 	dest_pr_reg->pr_res_type = type;
3486 	pr_reg->pr_res_scope = scope;
3487 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3488 	/*
3489 	 * Increment PRGeneration for existing registrations..
3490 	 */
3491 	if (!new_reg)
3492 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3493 	spin_unlock(&dev->dev_reservation_lock);
3494 
3495 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3496 		" created new reservation holder TYPE: %s on object RTPI:"
3497 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->fabric_name,
3498 		core_scsi3_pr_dump_type(type), rtpi,
3499 		dest_pr_reg->pr_res_generation);
3500 	pr_debug("SPC-3 PR Successfully moved reservation from"
3501 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3502 		tf_ops->fabric_name, pr_reg_nacl->initiatorname,
3503 		i_buf, dest_tf_ops->fabric_name,
3504 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3505 		iport_ptr : "");
3506 	/*
3507 	 * It is now safe to release configfs group dependencies for destination
3508 	 * of Transport ID Initiator Device/Port Identifier
3509 	 */
3510 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3511 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3512 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3513 	/*
3514 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3515 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3516 	 */
3517 	if (unreg) {
3518 		spin_lock(&pr_tmpl->registration_lock);
3519 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3520 		spin_unlock(&pr_tmpl->registration_lock);
3521 	} else
3522 		core_scsi3_put_pr_reg(pr_reg);
3523 
3524 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3525 
3526 	core_scsi3_put_pr_reg(dest_pr_reg);
3527 	return 0;
3528 out:
3529 	if (buf)
3530 		transport_kunmap_data_sg(cmd);
3531 	if (dest_se_deve)
3532 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3533 	if (dest_node_acl)
3534 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3535 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3536 
3537 out_put_pr_reg:
3538 	core_scsi3_put_pr_reg(pr_reg);
3539 	return ret;
3540 }
3541 
3542 static sense_reason_t
3543 target_try_pr_out_pt(struct se_cmd *cmd, u8 sa, u64 res_key, u64 sa_res_key,
3544 		     u8 type, bool aptpl, bool all_tg_pt, bool spec_i_pt)
3545 {
3546 	struct exec_cmd_ops *ops = cmd->protocol_data;
3547 
3548 	if (!cmd->se_sess || !cmd->se_lun) {
3549 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3550 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3551 	}
3552 
3553 	if (!ops->execute_pr_out) {
3554 		pr_err("SPC-3 PR: Device has been configured for PR passthrough but it's not supported by the backend.\n");
3555 		return TCM_UNSUPPORTED_SCSI_OPCODE;
3556 	}
3557 
3558 	switch (sa) {
3559 	case PRO_REGISTER_AND_MOVE:
3560 	case PRO_REPLACE_LOST_RESERVATION:
3561 		pr_err("SPC-3 PR: PRO_REGISTER_AND_MOVE and PRO_REPLACE_LOST_RESERVATION are not supported by PR passthrough.\n");
3562 		return TCM_UNSUPPORTED_SCSI_OPCODE;
3563 	}
3564 
3565 	if (spec_i_pt || all_tg_pt) {
3566 		pr_err("SPC-3 PR: SPEC_I_PT and ALL_TG_PT are not supported by PR passthrough.\n");
3567 		return TCM_UNSUPPORTED_SCSI_OPCODE;
3568 	}
3569 
3570 	return ops->execute_pr_out(cmd, sa, res_key, sa_res_key, type, aptpl);
3571 }
3572 
3573 /*
3574  * See spc4r17 section 6.14 Table 170
3575  */
3576 sense_reason_t
3577 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3578 {
3579 	struct se_device *dev = cmd->se_dev;
3580 	unsigned char *cdb = &cmd->t_task_cdb[0];
3581 	unsigned char *buf;
3582 	u64 res_key, sa_res_key;
3583 	int sa, scope, type, aptpl;
3584 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3585 	sense_reason_t ret;
3586 
3587 	/*
3588 	 * Following spc2r20 5.5.1 Reservations overview:
3589 	 *
3590 	 * If a logical unit has been reserved by any RESERVE command and is
3591 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3592 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3593 	 * initiator or service action and shall terminate with a RESERVATION
3594 	 * CONFLICT status.
3595 	 */
3596 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3597 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3598 			" SPC-2 reservation is held, returning"
3599 			" RESERVATION_CONFLICT\n");
3600 		return TCM_RESERVATION_CONFLICT;
3601 	}
3602 
3603 	/*
3604 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3605 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3606 	 */
3607 	if (!cmd->se_sess)
3608 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3609 
3610 	if (cmd->data_length < 24) {
3611 		pr_warn("SPC-PR: Received PR OUT parameter list"
3612 			" length too small: %u\n", cmd->data_length);
3613 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3614 	}
3615 
3616 	/*
3617 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3618 	 */
3619 	sa = (cdb[1] & 0x1f);
3620 	scope = (cdb[2] & 0xf0);
3621 	type = (cdb[2] & 0x0f);
3622 
3623 	buf = transport_kmap_data_sg(cmd);
3624 	if (!buf)
3625 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3626 
3627 	/*
3628 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3629 	 */
3630 	res_key = get_unaligned_be64(&buf[0]);
3631 	sa_res_key = get_unaligned_be64(&buf[8]);
3632 	/*
3633 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3634 	 * SCSI TransportIDs.
3635 	 */
3636 	if (sa != PRO_REGISTER_AND_MOVE) {
3637 		spec_i_pt = (buf[20] & 0x08);
3638 		all_tg_pt = (buf[20] & 0x04);
3639 		aptpl = (buf[20] & 0x01);
3640 	} else {
3641 		aptpl = (buf[17] & 0x01);
3642 		unreg = (buf[17] & 0x02);
3643 	}
3644 	/*
3645 	 * If the backend device has been configured to force APTPL metadata
3646 	 * write-out, go ahead and propigate aptpl=1 down now.
3647 	 */
3648 	if (dev->dev_attrib.force_pr_aptpl)
3649 		aptpl = 1;
3650 
3651 	transport_kunmap_data_sg(cmd);
3652 	buf = NULL;
3653 
3654 	/*
3655 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3656 	 */
3657 	if (spec_i_pt && (sa != PRO_REGISTER))
3658 		return TCM_INVALID_PARAMETER_LIST;
3659 
3660 	/*
3661 	 * From spc4r17 section 6.14:
3662 	 *
3663 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3664 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3665 	 * the command shall be terminated with CHECK CONDITION status, with
3666 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3667 	 * code set to PARAMETER LIST LENGTH ERROR.
3668 	 */
3669 	if (!spec_i_pt && (sa != PRO_REGISTER_AND_MOVE) &&
3670 	    (cmd->data_length != 24)) {
3671 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3672 			" list length: %u\n", cmd->data_length);
3673 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3674 	}
3675 
3676 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) {
3677 		ret = target_try_pr_out_pt(cmd, sa, res_key, sa_res_key, type,
3678 					   aptpl, all_tg_pt, spec_i_pt);
3679 		goto done;
3680 	}
3681 
3682 	/*
3683 	 * (core_scsi3_emulate_pro_* function parameters
3684 	 * are defined by spc4r17 Table 174:
3685 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3686 	 */
3687 	switch (sa) {
3688 	case PRO_REGISTER:
3689 		ret = core_scsi3_emulate_pro_register(cmd,
3690 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3691 		break;
3692 	case PRO_RESERVE:
3693 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3694 		break;
3695 	case PRO_RELEASE:
3696 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3697 		break;
3698 	case PRO_CLEAR:
3699 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3700 		break;
3701 	case PRO_PREEMPT:
3702 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3703 					res_key, sa_res_key, PREEMPT);
3704 		break;
3705 	case PRO_PREEMPT_AND_ABORT:
3706 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3707 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3708 		break;
3709 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3710 		ret = core_scsi3_emulate_pro_register(cmd,
3711 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3712 		break;
3713 	case PRO_REGISTER_AND_MOVE:
3714 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3715 				sa_res_key, aptpl, unreg);
3716 		break;
3717 	default:
3718 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3719 			" action: 0x%02x\n", sa);
3720 		return TCM_INVALID_CDB_FIELD;
3721 	}
3722 
3723 done:
3724 	if (!ret)
3725 		target_complete_cmd(cmd, SAM_STAT_GOOD);
3726 	return ret;
3727 }
3728 
3729 /*
3730  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3731  *
3732  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3733  */
3734 static sense_reason_t
3735 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3736 {
3737 	struct se_device *dev = cmd->se_dev;
3738 	struct t10_pr_registration *pr_reg;
3739 	unsigned char *buf;
3740 	u32 add_len = 0, off = 8;
3741 
3742 	if (cmd->data_length < 8) {
3743 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3744 			" too small\n", cmd->data_length);
3745 		return TCM_INVALID_CDB_FIELD;
3746 	}
3747 
3748 	buf = transport_kmap_data_sg(cmd);
3749 	if (!buf)
3750 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3751 
3752 	put_unaligned_be32(dev->t10_pr.pr_generation, buf);
3753 
3754 	spin_lock(&dev->t10_pr.registration_lock);
3755 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3756 			pr_reg_list) {
3757 		/*
3758 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3759 		 * next reservation key list descriptor.
3760 		 */
3761 		if (off + 8 <= cmd->data_length) {
3762 			put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3763 			off += 8;
3764 		}
3765 		/*
3766 		 * SPC5r17: 6.16.2 READ KEYS service action
3767 		 * The ADDITIONAL LENGTH field indicates the number of bytes in
3768 		 * the Reservation key list. The contents of the ADDITIONAL
3769 		 * LENGTH field are not altered based on the allocation length
3770 		 */
3771 		add_len += 8;
3772 	}
3773 	spin_unlock(&dev->t10_pr.registration_lock);
3774 
3775 	put_unaligned_be32(add_len, &buf[4]);
3776 	target_set_cmd_data_length(cmd, 8 + add_len);
3777 
3778 	transport_kunmap_data_sg(cmd);
3779 
3780 	return 0;
3781 }
3782 
3783 /*
3784  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3785  *
3786  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3787  */
3788 static sense_reason_t
3789 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3790 {
3791 	struct se_device *dev = cmd->se_dev;
3792 	struct t10_pr_registration *pr_reg;
3793 	unsigned char *buf;
3794 	u64 pr_res_key;
3795 	u32 add_len = 0;
3796 
3797 	if (cmd->data_length < 8) {
3798 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3799 			" too small\n", cmd->data_length);
3800 		return TCM_INVALID_CDB_FIELD;
3801 	}
3802 
3803 	buf = transport_kmap_data_sg(cmd);
3804 	if (!buf)
3805 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3806 
3807 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3808 
3809 	spin_lock(&dev->dev_reservation_lock);
3810 	pr_reg = dev->dev_pr_res_holder;
3811 	if (pr_reg) {
3812 		/*
3813 		 * Set the Additional Length to 16 when a reservation is held
3814 		 */
3815 		add_len = 16;
3816 		put_unaligned_be32(add_len, &buf[4]);
3817 
3818 		if (cmd->data_length < 22)
3819 			goto err;
3820 
3821 		/*
3822 		 * Set the Reservation key.
3823 		 *
3824 		 * From spc4r17, section 5.7.10:
3825 		 * A persistent reservation holder has its reservation key
3826 		 * returned in the parameter data from a PERSISTENT
3827 		 * RESERVE IN command with READ RESERVATION service action as
3828 		 * follows:
3829 		 * a) For a persistent reservation of the type Write Exclusive
3830 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3831 		 *      the reservation key shall be set to zero; or
3832 		 * b) For all other persistent reservation types, the
3833 		 *    reservation key shall be set to the registered
3834 		 *    reservation key for the I_T nexus that holds the
3835 		 *    persistent reservation.
3836 		 */
3837 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3838 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3839 			pr_res_key = 0;
3840 		else
3841 			pr_res_key = pr_reg->pr_res_key;
3842 
3843 		put_unaligned_be64(pr_res_key, &buf[8]);
3844 		/*
3845 		 * Set the SCOPE and TYPE
3846 		 */
3847 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3848 			  (pr_reg->pr_res_type & 0x0f);
3849 	}
3850 
3851 	target_set_cmd_data_length(cmd, 8 + add_len);
3852 
3853 err:
3854 	spin_unlock(&dev->dev_reservation_lock);
3855 	transport_kunmap_data_sg(cmd);
3856 
3857 	return 0;
3858 }
3859 
3860 /*
3861  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3862  *
3863  * See spc4r17 section 6.13.4 Table 165
3864  */
3865 static sense_reason_t
3866 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3867 {
3868 	struct se_device *dev = cmd->se_dev;
3869 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3870 	unsigned char *buf;
3871 	u16 len = 8; /* Hardcoded to 8. */
3872 
3873 	if (cmd->data_length < 6) {
3874 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3875 			" %u too small\n", cmd->data_length);
3876 		return TCM_INVALID_CDB_FIELD;
3877 	}
3878 
3879 	buf = transport_kmap_data_sg(cmd);
3880 	if (!buf)
3881 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3882 
3883 	put_unaligned_be16(len, &buf[0]);
3884 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3885 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3886 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3887 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3888 	/*
3889 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3890 	 * set the TMV: Task Mask Valid bit.
3891 	 */
3892 	buf[3] |= 0x80;
3893 	/*
3894 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3895 	 */
3896 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3897 	/*
3898 	 * PTPL_A: Persistence across Target Power Loss Active bit
3899 	 */
3900 	if (pr_tmpl->pr_aptpl_active)
3901 		buf[3] |= 0x01;
3902 	/*
3903 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3904 	 */
3905 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3906 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3907 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3908 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3909 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3910 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3911 
3912 	target_set_cmd_data_length(cmd, len);
3913 
3914 	transport_kunmap_data_sg(cmd);
3915 
3916 	return 0;
3917 }
3918 
3919 /*
3920  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3921  *
3922  * See spc4r17 section 6.13.5 Table 168 and 169
3923  */
3924 static sense_reason_t
3925 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3926 {
3927 	struct se_device *dev = cmd->se_dev;
3928 	struct se_node_acl *se_nacl;
3929 	struct se_portal_group *se_tpg;
3930 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3931 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3932 	unsigned char *buf;
3933 	u32 add_desc_len = 0, add_len = 0;
3934 	u32 off = 8; /* off into first Full Status descriptor */
3935 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3936 	int exp_desc_len, desc_len;
3937 	bool all_reg = false;
3938 
3939 	if (cmd->data_length < 8) {
3940 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3941 			" too small\n", cmd->data_length);
3942 		return TCM_INVALID_CDB_FIELD;
3943 	}
3944 
3945 	buf = transport_kmap_data_sg(cmd);
3946 	if (!buf)
3947 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3948 
3949 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3950 
3951 	spin_lock(&dev->dev_reservation_lock);
3952 	if (dev->dev_pr_res_holder) {
3953 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3954 
3955 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3956 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3957 			all_reg = true;
3958 			pr_res_type = pr_holder->pr_res_type;
3959 			pr_res_scope = pr_holder->pr_res_scope;
3960 		}
3961 	}
3962 	spin_unlock(&dev->dev_reservation_lock);
3963 
3964 	spin_lock(&pr_tmpl->registration_lock);
3965 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3966 			&pr_tmpl->registration_list, pr_reg_list) {
3967 
3968 		se_nacl = pr_reg->pr_reg_nacl;
3969 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3970 		add_desc_len = 0;
3971 
3972 		atomic_inc_mb(&pr_reg->pr_res_holders);
3973 		spin_unlock(&pr_tmpl->registration_lock);
3974 		/*
3975 		 * Determine expected length of $FABRIC_MOD specific
3976 		 * TransportID full status descriptor..
3977 		 */
3978 		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
3979 					&format_code);
3980 		if (exp_desc_len < 0 ||
3981 		    exp_desc_len + add_len > cmd->data_length) {
3982 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3983 				" out of buffer: %d\n", cmd->data_length);
3984 			spin_lock(&pr_tmpl->registration_lock);
3985 			atomic_dec_mb(&pr_reg->pr_res_holders);
3986 			break;
3987 		}
3988 		/*
3989 		 * Set RESERVATION KEY
3990 		 */
3991 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3992 		off += 8;
3993 		off += 4; /* Skip Over Reserved area */
3994 
3995 		/*
3996 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3997 		 */
3998 		if (pr_reg->pr_reg_all_tg_pt)
3999 			buf[off] = 0x02;
4000 		/*
4001 		 * The struct se_lun pointer will be present for the
4002 		 * reservation holder for PR_HOLDER bit.
4003 		 *
4004 		 * Also, if this registration is the reservation
4005 		 * holder or there is an All Registrants reservation
4006 		 * active, fill in SCOPE and TYPE in the next byte.
4007 		 */
4008 		if (pr_reg->pr_res_holder) {
4009 			buf[off++] |= 0x01;
4010 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
4011 				     (pr_reg->pr_res_type & 0x0f);
4012 		} else if (all_reg) {
4013 			buf[off++] |= 0x01;
4014 			buf[off++] = (pr_res_scope & 0xf0) |
4015 				     (pr_res_type & 0x0f);
4016 		} else {
4017 			off += 2;
4018 		}
4019 
4020 		off += 4; /* Skip over reserved area */
4021 		/*
4022 		 * From spc4r17 6.3.15:
4023 		 *
4024 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4025 		 * IDENTIFIER field contains the relative port identifier (see
4026 		 * 3.1.120) of the target port that is part of the I_T nexus
4027 		 * described by this full status descriptor. If the ALL_TG_PT
4028 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4029 		 * IDENTIFIER field are not defined by this standard.
4030 		 */
4031 		if (!pr_reg->pr_reg_all_tg_pt) {
4032 			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;
4033 
4034 			put_unaligned_be16(sep_rtpi, &buf[off]);
4035 			off += 2;
4036 		} else
4037 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
4038 
4039 		buf[off+4] = se_tpg->proto_id;
4040 
4041 		/*
4042 		 * Now, have the $FABRIC_MOD fill in the transport ID.
4043 		 */
4044 		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
4045 				&format_code, &buf[off+4]);
4046 
4047 		spin_lock(&pr_tmpl->registration_lock);
4048 		atomic_dec_mb(&pr_reg->pr_res_holders);
4049 
4050 		if (desc_len < 0)
4051 			break;
4052 		/*
4053 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4054 		 */
4055 		put_unaligned_be32(desc_len, &buf[off]);
4056 		off += 4;
4057 		/*
4058 		 * Size of full desctipor header minus TransportID
4059 		 * containing $FABRIC_MOD specific) initiator device/port
4060 		 * WWN information.
4061 		 *
4062 		 *  See spc4r17 Section 6.13.5 Table 169
4063 		 */
4064 		add_desc_len = (24 + desc_len);
4065 
4066 		off += desc_len;
4067 		add_len += add_desc_len;
4068 	}
4069 	spin_unlock(&pr_tmpl->registration_lock);
4070 	/*
4071 	 * Set ADDITIONAL_LENGTH
4072 	 */
4073 	put_unaligned_be32(add_len, &buf[4]);
4074 	target_set_cmd_data_length(cmd, 8 + add_len);
4075 
4076 	transport_kunmap_data_sg(cmd);
4077 
4078 	return 0;
4079 }
4080 
4081 static sense_reason_t target_try_pr_in_pt(struct se_cmd *cmd, u8 sa)
4082 {
4083 	struct exec_cmd_ops *ops = cmd->protocol_data;
4084 	unsigned char *buf;
4085 	sense_reason_t ret;
4086 
4087 	if (cmd->data_length < 8) {
4088 		pr_err("PRIN SA SCSI Data Length: %u too small\n",
4089 		       cmd->data_length);
4090 		return TCM_INVALID_CDB_FIELD;
4091 	}
4092 
4093 	if (!ops->execute_pr_in) {
4094 		pr_err("SPC-3 PR: Device has been configured for PR passthrough but it's not supported by the backend.\n");
4095 		return TCM_UNSUPPORTED_SCSI_OPCODE;
4096 	}
4097 
4098 	if (sa == PRI_READ_FULL_STATUS) {
4099 		pr_err("SPC-3 PR: PRI_READ_FULL_STATUS is not supported by PR passthrough.\n");
4100 		return TCM_UNSUPPORTED_SCSI_OPCODE;
4101 	}
4102 
4103 	buf = transport_kmap_data_sg(cmd);
4104 	if (!buf)
4105 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
4106 
4107 	ret = ops->execute_pr_in(cmd, sa, buf);
4108 
4109 	transport_kunmap_data_sg(cmd);
4110 	return ret;
4111 }
4112 
4113 sense_reason_t
4114 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4115 {
4116 	u8 sa = cmd->t_task_cdb[1] & 0x1f;
4117 	sense_reason_t ret;
4118 
4119 	/*
4120 	 * Following spc2r20 5.5.1 Reservations overview:
4121 	 *
4122 	 * If a logical unit has been reserved by any RESERVE command and is
4123 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4124 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4125 	 * initiator or service action and shall terminate with a RESERVATION
4126 	 * CONFLICT status.
4127 	 */
4128 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4129 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4130 			" SPC-2 reservation is held, returning"
4131 			" RESERVATION_CONFLICT\n");
4132 		return TCM_RESERVATION_CONFLICT;
4133 	}
4134 
4135 	if (cmd->se_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) {
4136 		ret = target_try_pr_in_pt(cmd, sa);
4137 		goto done;
4138 	}
4139 
4140 	switch (sa) {
4141 	case PRI_READ_KEYS:
4142 		ret = core_scsi3_pri_read_keys(cmd);
4143 		break;
4144 	case PRI_READ_RESERVATION:
4145 		ret = core_scsi3_pri_read_reservation(cmd);
4146 		break;
4147 	case PRI_REPORT_CAPABILITIES:
4148 		ret = core_scsi3_pri_report_capabilities(cmd);
4149 		break;
4150 	case PRI_READ_FULL_STATUS:
4151 		ret = core_scsi3_pri_read_full_status(cmd);
4152 		break;
4153 	default:
4154 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4155 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4156 		return TCM_INVALID_CDB_FIELD;
4157 	}
4158 
4159 done:
4160 	if (!ret)
4161 		target_complete_cmd(cmd, SAM_STAT_GOOD);
4162 	return ret;
4163 }
4164 
4165 sense_reason_t
4166 target_check_reservation(struct se_cmd *cmd)
4167 {
4168 	struct se_device *dev = cmd->se_dev;
4169 	sense_reason_t ret;
4170 
4171 	if (!cmd->se_sess)
4172 		return 0;
4173 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4174 		return 0;
4175 	if (!dev->dev_attrib.emulate_pr)
4176 		return 0;
4177 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
4178 		return 0;
4179 
4180 	spin_lock(&dev->dev_reservation_lock);
4181 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4182 		ret = target_scsi2_reservation_check(cmd);
4183 	else
4184 		ret = target_scsi3_pr_reservation_check(cmd);
4185 	spin_unlock(&dev->dev_reservation_lock);
4186 
4187 	return ret;
4188 }
4189