xref: /linux/drivers/target/target_core_pr.c (revision f4cdf7ca9a1fdcca413157df19753f388a5a224e)
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 <linux/fs_struct.h>
22 #include <scsi/scsi_proto.h>
23 #include <linux/unaligned.h>
24 
25 #include <target/target_core_base.h>
26 #include <target/target_core_backend.h>
27 #include <target/target_core_fabric.h>
28 
29 #include "target_core_internal.h"
30 #include "target_core_pr.h"
31 #include "target_core_ua.h"
32 
33 /*
34  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
35  */
36 struct pr_transport_id_holder {
37 	struct t10_pr_registration *dest_pr_reg;
38 	struct se_portal_group *dest_tpg;
39 	struct se_node_acl *dest_node_acl;
40 	struct se_dev_entry *dest_se_deve;
41 	struct list_head dest_list;
42 };
43 
44 void core_pr_dump_initiator_port(
45 	struct t10_pr_registration *pr_reg,
46 	char *buf,
47 	u32 size)
48 {
49 	if (!pr_reg->isid_present_at_reg) {
50 		buf[0] = '\0';
51 		return;
52 	}
53 
54 	snprintf(buf, size, ",i,0x%s", pr_reg->pr_reg_isid);
55 }
56 
57 enum register_type {
58 	REGISTER,
59 	REGISTER_AND_IGNORE_EXISTING_KEY,
60 	REGISTER_AND_MOVE,
61 };
62 
63 enum preempt_type {
64 	PREEMPT,
65 	PREEMPT_AND_ABORT,
66 };
67 
68 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
69 					      struct t10_pr_registration *, int, int);
70 
71 static int is_reservation_holder(
72 	struct t10_pr_registration *pr_res_holder,
73 	struct t10_pr_registration *pr_reg)
74 {
75 	int pr_res_type;
76 
77 	if (pr_res_holder) {
78 		pr_res_type = pr_res_holder->pr_res_type;
79 
80 		return pr_res_holder == pr_reg ||
81 		       pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
82 		       pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG;
83 	}
84 	return 0;
85 }
86 
87 static sense_reason_t
88 target_scsi2_reservation_check(struct se_cmd *cmd)
89 {
90 	struct se_device *dev = cmd->se_dev;
91 	struct se_session *sess = cmd->se_sess;
92 
93 	switch (cmd->t_task_cdb[0]) {
94 	case INQUIRY:
95 	case RELEASE_6:
96 	case RELEASE_10:
97 		return 0;
98 	default:
99 		break;
100 	}
101 
102 	if (!dev->reservation_holder || !sess)
103 		return 0;
104 
105 	if (dev->reservation_holder->se_node_acl != sess->se_node_acl)
106 		return TCM_RESERVATION_CONFLICT;
107 
108 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
109 		if (dev->dev_res_bin_isid != sess->sess_bin_isid)
110 			return TCM_RESERVATION_CONFLICT;
111 	}
112 
113 	return 0;
114 }
115 
116 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
117 					struct se_node_acl *, struct se_session *);
118 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
119 
120 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
121 {
122 	struct se_session *se_sess = cmd->se_sess;
123 	struct se_device *dev = cmd->se_dev;
124 	struct t10_pr_registration *pr_reg;
125 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
126 	int conflict = 0;
127 
128 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
129 			se_sess);
130 	if (pr_reg) {
131 		/*
132 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
133 		 * behavior
134 		 *
135 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
136 		 * status, but no reservation shall be established and the
137 		 * persistent reservation shall not be changed, if the command
138 		 * is received from a) and b) below.
139 		 *
140 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
141 		 * status, but the persistent reservation shall not be released,
142 		 * if the command is received from a) and b)
143 		 *
144 		 * a) An I_T nexus that is a persistent reservation holder; or
145 		 * b) An I_T nexus that is registered if a registrants only or
146 		 *    all registrants type persistent reservation is present.
147 		 *
148 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
149 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
150 		 * as defined in SPC-2.
151 		 */
152 		if (pr_reg->pr_res_holder) {
153 			core_scsi3_put_pr_reg(pr_reg);
154 			return 1;
155 		}
156 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
157 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
158 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
159 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
160 			core_scsi3_put_pr_reg(pr_reg);
161 			return 1;
162 		}
163 		core_scsi3_put_pr_reg(pr_reg);
164 		conflict = 1;
165 	} else {
166 		/*
167 		 * Following spc2r20 5.5.1 Reservations overview:
168 		 *
169 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
170 		 * command with the REGISTER or the REGISTER AND IGNORE
171 		 * EXISTING KEY service action and is still registered by any
172 		 * initiator, all RESERVE commands and all RELEASE commands
173 		 * regardless of initiator shall conflict and shall terminate
174 		 * with a RESERVATION CONFLICT status.
175 		 */
176 		spin_lock(&pr_tmpl->registration_lock);
177 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
178 		spin_unlock(&pr_tmpl->registration_lock);
179 	}
180 
181 	if (conflict) {
182 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
183 			" while active SPC-3 registrations exist,"
184 			" returning RESERVATION_CONFLICT\n");
185 		return -EBUSY;
186 	}
187 
188 	return 0;
189 }
190 
191 void target_release_reservation(struct se_device *dev)
192 {
193 	dev->reservation_holder = NULL;
194 	dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
195 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
196 		dev->dev_res_bin_isid = 0;
197 		dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS_WITH_ISID;
198 	}
199 }
200 
201 sense_reason_t
202 target_scsi2_reservation_release(struct se_cmd *cmd)
203 {
204 	struct se_device *dev = cmd->se_dev;
205 	struct se_session *sess = cmd->se_sess;
206 	struct se_portal_group *tpg;
207 	int rc;
208 
209 	if (!sess || !sess->se_tpg)
210 		goto out;
211 	rc = target_check_scsi2_reservation_conflict(cmd);
212 	if (rc == 1)
213 		goto out;
214 	if (rc < 0)
215 		return TCM_RESERVATION_CONFLICT;
216 
217 	spin_lock(&dev->dev_reservation_lock);
218 	if (!dev->reservation_holder || !sess)
219 		goto out_unlock;
220 
221 	if (dev->reservation_holder->se_node_acl != sess->se_node_acl)
222 		goto out_unlock;
223 
224 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
225 		goto out_unlock;
226 
227 	target_release_reservation(dev);
228 	tpg = sess->se_tpg;
229 	pr_debug("SCSI-2 Released reservation for %s LUN: %llu ->"
230 		" MAPPED LUN: %llu for %s\n",
231 		tpg->se_tpg_tfo->fabric_name,
232 		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
233 		sess->se_node_acl->initiatorname);
234 
235 out_unlock:
236 	spin_unlock(&dev->dev_reservation_lock);
237 out:
238 	target_complete_cmd(cmd, SAM_STAT_GOOD);
239 	return 0;
240 }
241 
242 sense_reason_t
243 target_scsi2_reservation_reserve(struct se_cmd *cmd)
244 {
245 	struct se_device *dev = cmd->se_dev;
246 	struct se_session *sess = cmd->se_sess;
247 	struct se_portal_group *tpg;
248 	sense_reason_t ret = 0;
249 	int rc;
250 
251 	if ((cmd->t_task_cdb[1] & 0x01) &&
252 	    (cmd->t_task_cdb[1] & 0x02)) {
253 		pr_err("LongIO and Obsolete Bits set, returning ILLEGAL_REQUEST\n");
254 		return TCM_UNSUPPORTED_SCSI_OPCODE;
255 	}
256 	/*
257 	 * This is currently the case for target_core_mod passthrough struct se_cmd
258 	 * ops
259 	 */
260 	if (!sess || !sess->se_tpg)
261 		goto out;
262 	rc = target_check_scsi2_reservation_conflict(cmd);
263 	if (rc == 1)
264 		goto out;
265 
266 	if (rc < 0)
267 		return TCM_RESERVATION_CONFLICT;
268 
269 	tpg = sess->se_tpg;
270 	spin_lock(&dev->dev_reservation_lock);
271 	if (dev->reservation_holder &&
272 	    dev->reservation_holder->se_node_acl != sess->se_node_acl) {
273 		pr_err("SCSI-2 RESERVATION CONFLICT for %s fabric\n",
274 			tpg->se_tpg_tfo->fabric_name);
275 		pr_err("Original reserver LUN: %llu %s\n",
276 			cmd->se_lun->unpacked_lun,
277 			dev->reservation_holder->se_node_acl->initiatorname);
278 		pr_err("Current attempt - LUN: %llu -> MAPPED LUN: %llu"
279 			" from %s \n", cmd->se_lun->unpacked_lun,
280 			cmd->orig_fe_lun,
281 			sess->se_node_acl->initiatorname);
282 		ret = TCM_RESERVATION_CONFLICT;
283 		goto out_unlock;
284 	}
285 
286 	dev->reservation_holder = sess;
287 	dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS;
288 	if (sess->sess_bin_isid != 0) {
289 		dev->dev_res_bin_isid = sess->sess_bin_isid;
290 		dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS_WITH_ISID;
291 	}
292 	pr_debug("SCSI-2 Reserved %s LUN: %llu -> MAPPED LUN: %llu"
293 		" for %s\n", tpg->se_tpg_tfo->fabric_name,
294 		cmd->se_lun->unpacked_lun, cmd->orig_fe_lun,
295 		sess->se_node_acl->initiatorname);
296 
297 out_unlock:
298 	spin_unlock(&dev->dev_reservation_lock);
299 out:
300 	if (!ret)
301 		target_complete_cmd(cmd, SAM_STAT_GOOD);
302 	return ret;
303 }
304 
305 
306 /*
307  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
308  *
309  * This function is called by those initiator ports who are *NOT*
310  * the active PR reservation holder when a reservation is present.
311  */
312 static int core_scsi3_pr_seq_non_holder(struct se_cmd *cmd, u32 pr_reg_type,
313 					bool isid_mismatch)
314 {
315 	unsigned char *cdb = cmd->t_task_cdb;
316 	struct se_session *se_sess = cmd->se_sess;
317 	struct se_node_acl *nacl = se_sess->se_node_acl;
318 	int other_cdb = 0;
319 	int registered_nexus = 0, ret = 1; /* Conflict by default */
320 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
321 	int we = 0; /* Write Exclusive */
322 	int legacy = 0; /* Act like a legacy device and return
323 			 * RESERVATION CONFLICT on some CDBs */
324 
325 	if (isid_mismatch) {
326 		registered_nexus = 0;
327 	} else {
328 		struct se_dev_entry *se_deve;
329 
330 		rcu_read_lock();
331 		se_deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
332 		if (se_deve)
333 			registered_nexus = test_bit(DEF_PR_REG_ACTIVE,
334 						    &se_deve->deve_flags);
335 		rcu_read_unlock();
336 	}
337 
338 	switch (pr_reg_type) {
339 	case PR_TYPE_WRITE_EXCLUSIVE:
340 		we = 1;
341 		fallthrough;
342 	case PR_TYPE_EXCLUSIVE_ACCESS:
343 		/*
344 		 * Some commands are only allowed for the persistent reservation
345 		 * holder.
346 		 */
347 		break;
348 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
349 		we = 1;
350 		fallthrough;
351 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
352 		/*
353 		 * Some commands are only allowed for registered I_T Nexuses.
354 		 */
355 		reg_only = 1;
356 		break;
357 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
358 		we = 1;
359 		fallthrough;
360 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
361 		/*
362 		 * Each registered I_T Nexus is a reservation holder.
363 		 */
364 		all_reg = 1;
365 		break;
366 	default:
367 		return -EINVAL;
368 	}
369 	/*
370 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
371 	 */
372 	switch (cdb[0]) {
373 	case SECURITY_PROTOCOL_IN:
374 		if (registered_nexus)
375 			return 0;
376 		ret = (we) ? 0 : 1;
377 		break;
378 	case MODE_SENSE:
379 	case MODE_SENSE_10:
380 	case READ_ATTRIBUTE:
381 	case READ_BUFFER:
382 	case RECEIVE_DIAGNOSTIC:
383 		if (legacy) {
384 			ret = 1;
385 			break;
386 		}
387 		if (registered_nexus) {
388 			ret = 0;
389 			break;
390 		}
391 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
392 		break;
393 	case PERSISTENT_RESERVE_OUT:
394 		/*
395 		 * This follows PERSISTENT_RESERVE_OUT service actions that
396 		 * are allowed in the presence of various reservations.
397 		 * See spc4r17, table 46
398 		 */
399 		switch (cdb[1] & 0x1f) {
400 		case PRO_CLEAR:
401 		case PRO_PREEMPT:
402 		case PRO_PREEMPT_AND_ABORT:
403 			ret = (registered_nexus) ? 0 : 1;
404 			break;
405 		case PRO_REGISTER:
406 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
407 			ret = 0;
408 			break;
409 		case PRO_REGISTER_AND_MOVE:
410 		case PRO_RESERVE:
411 			ret = 1;
412 			break;
413 		case PRO_RELEASE:
414 			ret = (registered_nexus) ? 0 : 1;
415 			break;
416 		default:
417 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
418 				" action: 0x%02x\n", cdb[1] & 0x1f);
419 			return -EINVAL;
420 		}
421 		break;
422 	case RELEASE_6:
423 	case RELEASE_10:
424 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
425 		ret = 0;
426 		break;
427 	case RESERVE_6:
428 	case RESERVE_10:
429 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
430 		ret = 0;
431 		break;
432 	case TEST_UNIT_READY:
433 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
434 		break;
435 	case MAINTENANCE_IN:
436 		switch (cdb[1] & 0x1f) {
437 		case MI_MANAGEMENT_PROTOCOL_IN:
438 			if (registered_nexus) {
439 				ret = 0;
440 				break;
441 			}
442 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
443 			break;
444 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
445 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
446 			if (legacy) {
447 				ret = 1;
448 				break;
449 			}
450 			if (registered_nexus) {
451 				ret = 0;
452 				break;
453 			}
454 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
455 			break;
456 		case MI_REPORT_ALIASES:
457 		case MI_REPORT_IDENTIFYING_INFORMATION:
458 		case MI_REPORT_PRIORITY:
459 		case MI_REPORT_TARGET_PGS:
460 		case MI_REPORT_TIMESTAMP:
461 			ret = 0; /* Allowed */
462 			break;
463 		default:
464 			pr_err("Unknown MI Service Action: 0x%02x\n",
465 				(cdb[1] & 0x1f));
466 			return -EINVAL;
467 		}
468 		break;
469 	case ACCESS_CONTROL_IN:
470 	case ACCESS_CONTROL_OUT:
471 	case INQUIRY:
472 	case LOG_SENSE:
473 	case SERVICE_ACTION_IN_12:
474 	case READ_CAPACITY:
475 	case REPORT_LUNS:
476 	case REQUEST_SENSE:
477 	case PERSISTENT_RESERVE_IN:
478 		ret = 0; /*/ Allowed CDBs */
479 		break;
480 	default:
481 		other_cdb = 1;
482 		break;
483 	}
484 	/*
485 	 * Case where the CDB is explicitly allowed in the above switch
486 	 * statement.
487 	 */
488 	if (!ret && !other_cdb) {
489 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
490 			" reservation holder\n", cdb[0],
491 			core_scsi3_pr_dump_type(pr_reg_type));
492 
493 		return ret;
494 	}
495 	/*
496 	 * Check if write exclusive initiator ports *NOT* holding the
497 	 * WRITE_EXCLUSIVE_* reservation.
498 	 */
499 	if (we && !registered_nexus) {
500 		if (cmd->data_direction == DMA_TO_DEVICE) {
501 			/*
502 			 * Conflict for write exclusive
503 			 */
504 			pr_debug("%s Conflict for unregistered nexus"
505 				" %s CDB: 0x%02x to %s reservation\n",
506 				transport_dump_cmd_direction(cmd),
507 				se_sess->se_node_acl->initiatorname, cdb[0],
508 				core_scsi3_pr_dump_type(pr_reg_type));
509 			return 1;
510 		} else {
511 			/*
512 			 * Allow non WRITE CDBs for all Write Exclusive
513 			 * PR TYPEs to pass for registered and
514 			 * non-registered_nexuxes NOT holding the reservation.
515 			 *
516 			 * We only make noise for the unregisterd nexuses,
517 			 * as we expect registered non-reservation holding
518 			 * nexuses to issue CDBs.
519 			 */
520 
521 			if (!registered_nexus) {
522 				pr_debug("Allowing implicit CDB: 0x%02x"
523 					" for %s reservation on unregistered"
524 					" nexus\n", cdb[0],
525 					core_scsi3_pr_dump_type(pr_reg_type));
526 			}
527 
528 			return 0;
529 		}
530 	} else if ((reg_only) || (all_reg)) {
531 		if (registered_nexus) {
532 			/*
533 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
534 			 * allow commands from registered nexuses.
535 			 */
536 
537 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
538 				" reservation\n", cdb[0],
539 				core_scsi3_pr_dump_type(pr_reg_type));
540 
541 			return 0;
542 		}
543        } else if (we && registered_nexus) {
544                /*
545                 * Reads are allowed for Write Exclusive locks
546                 * from all registrants.
547                 */
548                if (cmd->data_direction == DMA_FROM_DEVICE) {
549                        pr_debug("Allowing READ CDB: 0x%02x for %s"
550                                " reservation\n", cdb[0],
551                                core_scsi3_pr_dump_type(pr_reg_type));
552 
553                        return 0;
554                }
555 	}
556 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
557 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
558 		(registered_nexus) ? "" : "un",
559 		se_sess->se_node_acl->initiatorname, cdb[0],
560 		core_scsi3_pr_dump_type(pr_reg_type));
561 
562 	return 1; /* Conflict by default */
563 }
564 
565 static sense_reason_t
566 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
567 {
568 	struct se_device *dev = cmd->se_dev;
569 	struct se_session *sess = cmd->se_sess;
570 	u32 pr_reg_type;
571 	bool isid_mismatch = false;
572 
573 	if (!dev->dev_pr_res_holder)
574 		return 0;
575 
576 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
577 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
578 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
579 		goto check_nonholder;
580 
581 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
582 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
583 		    sess->sess_bin_isid) {
584 			isid_mismatch = true;
585 			goto check_nonholder;
586 		}
587 	}
588 
589 	return 0;
590 
591 check_nonholder:
592 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type, isid_mismatch))
593 		return TCM_RESERVATION_CONFLICT;
594 	return 0;
595 }
596 
597 static u32 core_scsi3_pr_generation(struct se_device *dev)
598 {
599 	u32 prg;
600 
601 	/*
602 	 * PRGeneration field shall contain the value of a 32-bit wrapping
603 	 * counter mainted by the device server.
604 	 *
605 	 * Note that this is done regardless of Active Persist across
606 	 * Target PowerLoss (APTPL)
607 	 *
608 	 * See spc4r17 section 6.3.12 READ_KEYS service action
609 	 */
610 	spin_lock(&dev->dev_reservation_lock);
611 	prg = dev->t10_pr.pr_generation++;
612 	spin_unlock(&dev->dev_reservation_lock);
613 
614 	return prg;
615 }
616 
617 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
618 	struct se_device *dev,
619 	struct se_node_acl *nacl,
620 	struct se_lun *lun,
621 	struct se_dev_entry *dest_deve,
622 	u64 mapped_lun,
623 	unsigned char *isid,
624 	u64 sa_res_key,
625 	int all_tg_pt,
626 	int aptpl)
627 {
628 	struct t10_pr_registration *pr_reg;
629 
630 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
631 	if (!pr_reg) {
632 		pr_err("Unable to allocate struct t10_pr_registration\n");
633 		return NULL;
634 	}
635 
636 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
637 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
638 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
639 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
640 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
641 	atomic_set(&pr_reg->pr_res_holders, 0);
642 	pr_reg->pr_reg_nacl = nacl;
643 	/*
644 	 * For destination registrations for ALL_TG_PT=1 and SPEC_I_PT=1,
645 	 * the se_dev_entry->pr_ref will have been already obtained by
646 	 * core_get_se_deve_from_rtpi() or __core_scsi3_alloc_registration().
647 	 *
648 	 * Otherwise, locate se_dev_entry now and obtain a reference until
649 	 * registration completes in __core_scsi3_add_registration().
650 	 */
651 	if (dest_deve) {
652 		pr_reg->pr_reg_deve = dest_deve;
653 	} else {
654 		rcu_read_lock();
655 		pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
656 		if (!pr_reg->pr_reg_deve) {
657 			rcu_read_unlock();
658 			pr_err("Unable to locate PR deve %s mapped_lun: %llu\n",
659 				nacl->initiatorname, mapped_lun);
660 			kmem_cache_free(t10_pr_reg_cache, pr_reg);
661 			return NULL;
662 		}
663 		kref_get(&pr_reg->pr_reg_deve->pr_kref);
664 		rcu_read_unlock();
665 	}
666 	pr_reg->pr_res_mapped_lun = mapped_lun;
667 	pr_reg->pr_aptpl_target_lun = lun->unpacked_lun;
668 	pr_reg->tg_pt_sep_rtpi = lun->lun_tpg->tpg_rtpi;
669 	pr_reg->pr_res_key = sa_res_key;
670 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
671 	pr_reg->pr_reg_aptpl = aptpl;
672 	/*
673 	 * If an ISID value for this SCSI Initiator Port exists,
674 	 * save it to the registration now.
675 	 */
676 	if (isid != NULL) {
677 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
678 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
679 		pr_reg->isid_present_at_reg = 1;
680 	}
681 
682 	return pr_reg;
683 }
684 
685 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
686 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
687 
688 /*
689  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
690  * modes.
691  */
692 static struct t10_pr_registration *__core_scsi3_alloc_registration(
693 	struct se_device *dev,
694 	struct se_node_acl *nacl,
695 	struct se_lun *lun,
696 	struct se_dev_entry *deve,
697 	u64 mapped_lun,
698 	unsigned char *isid,
699 	u64 sa_res_key,
700 	int all_tg_pt,
701 	int aptpl)
702 {
703 	struct se_dev_entry *deve_tmp;
704 	struct se_node_acl *nacl_tmp;
705 	struct se_lun_acl *lacl_tmp;
706 	struct se_lun *lun_tmp, *next, *dest_lun;
707 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
708 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
709 	int ret;
710 	/*
711 	 * Create a registration for the I_T Nexus upon which the
712 	 * PROUT REGISTER was received.
713 	 */
714 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, lun, deve, mapped_lun,
715 						    isid, sa_res_key, all_tg_pt,
716 						    aptpl);
717 	if (!pr_reg)
718 		return NULL;
719 	/*
720 	 * Return pointer to pr_reg for ALL_TG_PT=0
721 	 */
722 	if (!all_tg_pt)
723 		return pr_reg;
724 	/*
725 	 * Create list of matching SCSI Initiator Port registrations
726 	 * for ALL_TG_PT=1
727 	 */
728 	spin_lock(&dev->se_port_lock);
729 	list_for_each_entry_safe(lun_tmp, next, &dev->dev_sep_list, lun_dev_link) {
730 		if (!percpu_ref_tryget_live(&lun_tmp->lun_ref))
731 			continue;
732 		spin_unlock(&dev->se_port_lock);
733 
734 		spin_lock(&lun_tmp->lun_deve_lock);
735 		list_for_each_entry(deve_tmp, &lun_tmp->lun_deve_list, lun_link) {
736 			/*
737 			 * This pointer will be NULL for demo mode MappedLUNs
738 			 * that have not been make explicit via a ConfigFS
739 			 * MappedLUN group for the SCSI Initiator Node ACL.
740 			 */
741 			if (!deve_tmp->se_lun_acl)
742 				continue;
743 
744 			lacl_tmp = deve_tmp->se_lun_acl;
745 			nacl_tmp = lacl_tmp->se_lun_nacl;
746 			/*
747 			 * Skip the matching struct se_node_acl that is allocated
748 			 * above..
749 			 */
750 			if (nacl == nacl_tmp)
751 				continue;
752 			/*
753 			 * Only perform PR registrations for target ports on
754 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
755 			 * arrived.
756 			 */
757 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
758 				continue;
759 			/*
760 			 * Look for a matching Initiator Node ACL in ASCII format
761 			 */
762 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
763 				continue;
764 
765 			kref_get(&deve_tmp->pr_kref);
766 			spin_unlock(&lun_tmp->lun_deve_lock);
767 			/*
768 			 * Grab a configfs group dependency that is released
769 			 * for the exception path at label out: below, or upon
770 			 * completion of adding ALL_TG_PT=1 registrations in
771 			 * __core_scsi3_add_registration()
772 			 */
773 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
774 			if (ret < 0) {
775 				pr_err("core_scsi3_lunacl_depend"
776 						"_item() failed\n");
777 				percpu_ref_put(&lun_tmp->lun_ref);
778 				kref_put(&deve_tmp->pr_kref, target_pr_kref_release);
779 				goto out;
780 			}
781 			/*
782 			 * Located a matching SCSI Initiator Port on a different
783 			 * port, allocate the pr_reg_atp and attach it to the
784 			 * pr_reg->pr_reg_atp_list that will be processed once
785 			 * the original *pr_reg is processed in
786 			 * __core_scsi3_add_registration()
787 			 */
788 			dest_lun = deve_tmp->se_lun;
789 
790 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
791 						nacl_tmp, dest_lun, deve_tmp,
792 						deve_tmp->mapped_lun, NULL,
793 						sa_res_key, all_tg_pt, aptpl);
794 			if (!pr_reg_atp) {
795 				percpu_ref_put(&lun_tmp->lun_ref);
796 				core_scsi3_lunacl_undepend_item(deve_tmp);
797 				goto out;
798 			}
799 
800 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
801 				      &pr_reg->pr_reg_atp_list);
802 			spin_lock(&lun_tmp->lun_deve_lock);
803 		}
804 		spin_unlock(&lun_tmp->lun_deve_lock);
805 
806 		spin_lock(&dev->se_port_lock);
807 		percpu_ref_put(&lun_tmp->lun_ref);
808 	}
809 	spin_unlock(&dev->se_port_lock);
810 
811 	return pr_reg;
812 out:
813 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
814 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
815 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
816 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
817 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
818 	}
819 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
820 	return NULL;
821 }
822 
823 int core_scsi3_alloc_aptpl_registration(
824 	struct t10_reservation *pr_tmpl,
825 	u64 sa_res_key,
826 	unsigned char *i_port,
827 	unsigned char *isid,
828 	u64 mapped_lun,
829 	unsigned char *t_port,
830 	u16 tpgt,
831 	u64 target_lun,
832 	int res_holder,
833 	int all_tg_pt,
834 	u8 type)
835 {
836 	struct t10_pr_registration *pr_reg;
837 
838 	if (!i_port || !t_port || !sa_res_key) {
839 		pr_err("Illegal parameters for APTPL registration\n");
840 		return -EINVAL;
841 	}
842 
843 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
844 	if (!pr_reg) {
845 		pr_err("Unable to allocate struct t10_pr_registration\n");
846 		return -ENOMEM;
847 	}
848 
849 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
850 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
851 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
852 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
853 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
854 	atomic_set(&pr_reg->pr_res_holders, 0);
855 	pr_reg->pr_reg_nacl = NULL;
856 	pr_reg->pr_reg_deve = NULL;
857 	pr_reg->pr_res_mapped_lun = mapped_lun;
858 	pr_reg->pr_aptpl_target_lun = target_lun;
859 	pr_reg->pr_res_key = sa_res_key;
860 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
861 	pr_reg->pr_reg_aptpl = 1;
862 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
863 	pr_reg->pr_res_type = type;
864 	/*
865 	 * If an ISID value had been saved in APTPL metadata for this
866 	 * SCSI Initiator Port, restore it now.
867 	 */
868 	if (isid != NULL) {
869 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
870 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
871 		pr_reg->isid_present_at_reg = 1;
872 	}
873 	/*
874 	 * Copy the i_port and t_port information from caller.
875 	 */
876 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
877 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
878 	pr_reg->pr_reg_tpgt = tpgt;
879 	/*
880 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
881 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
882 	 * the Initiator Node LUN ACL from the fabric module is created for
883 	 * this registration.
884 	 */
885 	pr_reg->pr_res_holder = res_holder;
886 
887 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
888 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
889 			" metadata\n", (res_holder) ? "+reservation" : "");
890 	return 0;
891 }
892 
893 static void core_scsi3_aptpl_reserve(
894 	struct se_device *dev,
895 	struct se_portal_group *tpg,
896 	struct se_node_acl *node_acl,
897 	struct t10_pr_registration *pr_reg)
898 {
899 	char i_buf[PR_REG_ISID_ID_LEN] = { };
900 
901 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
902 
903 	spin_lock(&dev->dev_reservation_lock);
904 	dev->dev_pr_res_holder = pr_reg;
905 	spin_unlock(&dev->dev_reservation_lock);
906 
907 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
908 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
909 		tpg->se_tpg_tfo->fabric_name,
910 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
911 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
912 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
913 		tpg->se_tpg_tfo->fabric_name, node_acl->initiatorname,
914 		i_buf);
915 }
916 
917 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
918 				struct t10_pr_registration *, enum register_type, int);
919 
920 static int __core_scsi3_check_aptpl_registration(
921 	struct se_device *dev,
922 	struct se_portal_group *tpg,
923 	struct se_lun *lun,
924 	u64 target_lun,
925 	struct se_node_acl *nacl,
926 	u64 mapped_lun)
927 {
928 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
929 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
930 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN] = { };
931 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN] = { };
932 	u16 tpgt;
933 
934 	/*
935 	 * Copy Initiator Port information from struct se_node_acl
936 	 */
937 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
938 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
939 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
940 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
941 	/*
942 	 * Look for the matching registrations+reservation from those
943 	 * created from APTPL metadata.  Note that multiple registrations
944 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
945 	 * TransportIDs.
946 	 */
947 	spin_lock(&pr_tmpl->aptpl_reg_lock);
948 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
949 				pr_reg_aptpl_list) {
950 
951 		if (!strcmp(pr_reg->pr_iport, i_port) &&
952 		     (pr_reg->pr_res_mapped_lun == mapped_lun) &&
953 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
954 		     (pr_reg->pr_reg_tpgt == tpgt) &&
955 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
956 			/*
957 			 * Obtain the ->pr_reg_deve pointer + reference, that
958 			 * is released by __core_scsi3_add_registration() below.
959 			 */
960 			rcu_read_lock();
961 			pr_reg->pr_reg_deve = target_nacl_find_deve(nacl, mapped_lun);
962 			if (!pr_reg->pr_reg_deve) {
963 				pr_err("Unable to locate PR APTPL %s mapped_lun:"
964 					" %llu\n", nacl->initiatorname, mapped_lun);
965 				rcu_read_unlock();
966 				continue;
967 			}
968 			kref_get(&pr_reg->pr_reg_deve->pr_kref);
969 			rcu_read_unlock();
970 
971 			pr_reg->pr_reg_nacl = nacl;
972 			pr_reg->tg_pt_sep_rtpi = lun->lun_tpg->tpg_rtpi;
973 			list_del(&pr_reg->pr_reg_aptpl_list);
974 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
975 			/*
976 			 * At this point all of the pointers in *pr_reg will
977 			 * be setup, so go ahead and add the registration.
978 			 */
979 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
980 			/*
981 			 * If this registration is the reservation holder,
982 			 * make that happen now..
983 			 */
984 			if (pr_reg->pr_res_holder)
985 				core_scsi3_aptpl_reserve(dev, tpg,
986 						nacl, pr_reg);
987 			/*
988 			 * Reenable pr_aptpl_active to accept new metadata
989 			 * updates once the SCSI device is active again..
990 			 */
991 			spin_lock(&pr_tmpl->aptpl_reg_lock);
992 			pr_tmpl->pr_aptpl_active = 1;
993 		}
994 	}
995 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
996 
997 	return 0;
998 }
999 
1000 int core_scsi3_check_aptpl_registration(
1001 	struct se_device *dev,
1002 	struct se_portal_group *tpg,
1003 	struct se_lun *lun,
1004 	struct se_node_acl *nacl,
1005 	u64 mapped_lun)
1006 {
1007 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
1008 		return 0;
1009 
1010 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
1011 						     lun->unpacked_lun, nacl,
1012 						     mapped_lun);
1013 }
1014 
1015 static void __core_scsi3_dump_registration(
1016 	const struct target_core_fabric_ops *tfo,
1017 	struct se_device *dev,
1018 	struct se_node_acl *nacl,
1019 	struct t10_pr_registration *pr_reg,
1020 	enum register_type register_type)
1021 {
1022 	struct se_portal_group *se_tpg = nacl->se_tpg;
1023 	char i_buf[PR_REG_ISID_ID_LEN] = { };
1024 
1025 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1026 
1027 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1028 		" Node: %s%s\n", tfo->fabric_name, (register_type == REGISTER_AND_MOVE) ?
1029 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
1030 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1031 		i_buf);
1032 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1033 		 tfo->fabric_name, tfo->tpg_get_wwn(se_tpg),
1034 		tfo->tpg_get_tag(se_tpg));
1035 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1036 		" Port(s)\n",  tfo->fabric_name,
1037 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1038 		dev->transport->name);
1039 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1040 		" 0x%08x  APTPL: %d\n", tfo->fabric_name,
1041 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1042 		pr_reg->pr_reg_aptpl);
1043 }
1044 
1045 static void __core_scsi3_add_registration(
1046 	struct se_device *dev,
1047 	struct se_node_acl *nacl,
1048 	struct t10_pr_registration *pr_reg,
1049 	enum register_type register_type,
1050 	int register_move)
1051 {
1052 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1053 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1054 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1055 	struct se_dev_entry *deve;
1056 
1057 	/*
1058 	 * Increment PRgeneration counter for struct se_device upon a successful
1059 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1060 	 *
1061 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1062 	 * action, the struct se_device->dev_reservation_lock will already be held,
1063 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1064 	 * for the REGISTER.
1065 	 */
1066 	pr_reg->pr_res_generation = (register_move) ?
1067 			dev->t10_pr.pr_generation++ :
1068 			core_scsi3_pr_generation(dev);
1069 
1070 	spin_lock(&pr_tmpl->registration_lock);
1071 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1072 
1073 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1074 	spin_unlock(&pr_tmpl->registration_lock);
1075 	/*
1076 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1077 	 */
1078 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1079 		goto out;
1080 	/*
1081 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1082 	 * allocated in __core_scsi3_alloc_registration()
1083 	 */
1084 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1085 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1086 		struct se_node_acl *nacl_tmp = pr_reg_tmp->pr_reg_nacl;
1087 
1088 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1089 
1090 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1091 
1092 		spin_lock(&pr_tmpl->registration_lock);
1093 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1094 			      &pr_tmpl->registration_list);
1095 
1096 		__core_scsi3_dump_registration(tfo, dev, nacl_tmp, pr_reg_tmp,
1097 					       register_type);
1098 		spin_unlock(&pr_tmpl->registration_lock);
1099 		/*
1100 		 * Drop configfs group dependency reference and deve->pr_kref
1101 		 * obtained from  __core_scsi3_alloc_registration() code.
1102 		 */
1103 		rcu_read_lock();
1104 		deve = pr_reg_tmp->pr_reg_deve;
1105 		if (deve) {
1106 			set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1107 			core_scsi3_lunacl_undepend_item(deve);
1108 			pr_reg_tmp->pr_reg_deve = NULL;
1109 		}
1110 		rcu_read_unlock();
1111 	}
1112 out:
1113 	/*
1114 	 * Drop deve->pr_kref obtained in __core_scsi3_do_alloc_registration()
1115 	 */
1116 	rcu_read_lock();
1117 	deve = pr_reg->pr_reg_deve;
1118 	if (deve) {
1119 		set_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1120 		kref_put(&deve->pr_kref, target_pr_kref_release);
1121 		pr_reg->pr_reg_deve = NULL;
1122 	}
1123 	rcu_read_unlock();
1124 }
1125 
1126 static int core_scsi3_alloc_registration(
1127 	struct se_device *dev,
1128 	struct se_node_acl *nacl,
1129 	struct se_lun *lun,
1130 	struct se_dev_entry *deve,
1131 	u64 mapped_lun,
1132 	unsigned char *isid,
1133 	u64 sa_res_key,
1134 	int all_tg_pt,
1135 	int aptpl,
1136 	enum register_type register_type,
1137 	int register_move)
1138 {
1139 	struct t10_pr_registration *pr_reg;
1140 
1141 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, lun, deve, mapped_lun,
1142 						 isid, sa_res_key, all_tg_pt,
1143 						 aptpl);
1144 	if (!pr_reg)
1145 		return -EPERM;
1146 
1147 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1148 			register_type, register_move);
1149 	return 0;
1150 }
1151 
1152 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1153 	struct se_device *dev,
1154 	struct se_node_acl *nacl,
1155 	unsigned char *isid)
1156 {
1157 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1158 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1159 
1160 	spin_lock(&pr_tmpl->registration_lock);
1161 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1162 			&pr_tmpl->registration_list, pr_reg_list) {
1163 		/*
1164 		 * First look for a matching struct se_node_acl
1165 		 */
1166 		if (pr_reg->pr_reg_nacl != nacl)
1167 			continue;
1168 
1169 		/*
1170 		 * If this registration does NOT contain a fabric provided
1171 		 * ISID, then we have found a match.
1172 		 */
1173 		if (!pr_reg->isid_present_at_reg) {
1174 			atomic_inc_mb(&pr_reg->pr_res_holders);
1175 			spin_unlock(&pr_tmpl->registration_lock);
1176 			return pr_reg;
1177 		}
1178 		/*
1179 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1180 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1181 		 * matching ISID to be provided by the local SCSI Initiator Port.
1182 		 */
1183 		if (!isid)
1184 			continue;
1185 		if (strcmp(isid, pr_reg->pr_reg_isid))
1186 			continue;
1187 
1188 		atomic_inc_mb(&pr_reg->pr_res_holders);
1189 		spin_unlock(&pr_tmpl->registration_lock);
1190 		return pr_reg;
1191 	}
1192 	spin_unlock(&pr_tmpl->registration_lock);
1193 
1194 	return NULL;
1195 }
1196 
1197 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1198 	struct se_device *dev,
1199 	struct se_node_acl *nacl,
1200 	struct se_session *sess)
1201 {
1202 	struct se_portal_group *tpg = nacl->se_tpg;
1203 	unsigned char buf[PR_REG_ISID_LEN] = { };
1204 	unsigned char *isid_ptr = NULL;
1205 
1206 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1207 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1208 					PR_REG_ISID_LEN);
1209 		isid_ptr = &buf[0];
1210 	}
1211 
1212 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1213 }
1214 
1215 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1216 {
1217 	atomic_dec_mb(&pr_reg->pr_res_holders);
1218 }
1219 
1220 static int core_scsi3_check_implicit_release(
1221 	struct se_device *dev,
1222 	struct t10_pr_registration *pr_reg)
1223 {
1224 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1225 	struct t10_pr_registration *pr_res_holder;
1226 	int ret = 0;
1227 
1228 	spin_lock(&dev->dev_reservation_lock);
1229 	pr_res_holder = dev->dev_pr_res_holder;
1230 	if (!pr_res_holder) {
1231 		spin_unlock(&dev->dev_reservation_lock);
1232 		return ret;
1233 	}
1234 	if (pr_res_holder == pr_reg) {
1235 		/*
1236 		 * Perform an implicit RELEASE if the registration that
1237 		 * is being released is holding the reservation.
1238 		 *
1239 		 * From spc4r17, section 5.7.11.1:
1240 		 *
1241 		 * e) If the I_T nexus is the persistent reservation holder
1242 		 *    and the persistent reservation is not an all registrants
1243 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1244 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1245 		 *    service action with the SERVICE ACTION RESERVATION KEY
1246 		 *    field set to zero (see 5.7.11.3).
1247 		 */
1248 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0, 1);
1249 		ret = 1;
1250 		/*
1251 		 * For 'All Registrants' reservation types, all existing
1252 		 * registrations are still processed as reservation holders
1253 		 * in core_scsi3_pr_seq_non_holder() after the initial
1254 		 * reservation holder is implicitly released here.
1255 		 */
1256 	} else if (pr_reg->pr_reg_all_tg_pt &&
1257 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1258 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1259 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1260 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1261 			" UNREGISTER while existing reservation with matching"
1262 			" key 0x%016Lx is present from another SCSI Initiator"
1263 			" Port\n", pr_reg->pr_res_key);
1264 		ret = -EPERM;
1265 	}
1266 	spin_unlock(&dev->dev_reservation_lock);
1267 
1268 	return ret;
1269 }
1270 
1271 static void __core_scsi3_free_registration(
1272 	struct se_device *dev,
1273 	struct t10_pr_registration *pr_reg,
1274 	struct list_head *preempt_and_abort_list,
1275 	int dec_holders)
1276 	__releases(&pr_tmpl->registration_lock)
1277 	__acquires(&pr_tmpl->registration_lock)
1278 {
1279 	const struct target_core_fabric_ops *tfo =
1280 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1281 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1282 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1283 	struct se_dev_entry *deve;
1284 	char i_buf[PR_REG_ISID_ID_LEN] = { };
1285 
1286 	lockdep_assert_held(&pr_tmpl->registration_lock);
1287 
1288 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1289 
1290 	if (!list_empty(&pr_reg->pr_reg_list))
1291 		list_del(&pr_reg->pr_reg_list);
1292 	/*
1293 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1294 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1295 	 */
1296 	if (dec_holders)
1297 		core_scsi3_put_pr_reg(pr_reg);
1298 
1299 	spin_unlock(&pr_tmpl->registration_lock);
1300 	/*
1301 	 * Wait until all reference from any other I_T nexuses for this
1302 	 * *pr_reg have been released.  Because list_del() is called above,
1303 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1304 	 * count back to zero, and we release *pr_reg.
1305 	 */
1306 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1307 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1308 				tfo->fabric_name);
1309 		cpu_relax();
1310 	}
1311 
1312 	rcu_read_lock();
1313 	deve = target_nacl_find_deve(nacl, pr_reg->pr_res_mapped_lun);
1314 	if (deve)
1315 		clear_bit(DEF_PR_REG_ACTIVE, &deve->deve_flags);
1316 	rcu_read_unlock();
1317 
1318 	spin_lock(&pr_tmpl->registration_lock);
1319 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1320 		" Node: %s%s\n", tfo->fabric_name,
1321 		pr_reg->pr_reg_nacl->initiatorname,
1322 		i_buf);
1323 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1324 		" Port(s)\n", tfo->fabric_name,
1325 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1326 		dev->transport->name);
1327 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1328 		" 0x%08x\n", tfo->fabric_name, pr_reg->pr_res_key,
1329 		pr_reg->pr_res_generation);
1330 
1331 	if (!preempt_and_abort_list) {
1332 		pr_reg->pr_reg_deve = NULL;
1333 		pr_reg->pr_reg_nacl = NULL;
1334 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1335 		return;
1336 	}
1337 	/*
1338 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1339 	 * are released once the ABORT_TASK_SET has completed..
1340 	 */
1341 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1342 }
1343 
1344 void core_scsi3_free_pr_reg_from_nacl(
1345 	struct se_device *dev,
1346 	struct se_node_acl *nacl)
1347 {
1348 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1349 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1350 	bool free_reg = false;
1351 	/*
1352 	 * If the passed se_node_acl matches the reservation holder,
1353 	 * release the reservation.
1354 	 */
1355 	spin_lock(&dev->dev_reservation_lock);
1356 	pr_res_holder = dev->dev_pr_res_holder;
1357 	if ((pr_res_holder != NULL) &&
1358 	    (pr_res_holder->pr_reg_nacl == nacl)) {
1359 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0, 1);
1360 		free_reg = true;
1361 	}
1362 	spin_unlock(&dev->dev_reservation_lock);
1363 	/*
1364 	 * Release any registration associated with the struct se_node_acl.
1365 	 */
1366 	spin_lock(&pr_tmpl->registration_lock);
1367 	if (pr_res_holder && free_reg)
1368 		__core_scsi3_free_registration(dev, pr_res_holder, NULL, 0);
1369 
1370 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1371 			&pr_tmpl->registration_list, pr_reg_list) {
1372 
1373 		if (pr_reg->pr_reg_nacl != nacl)
1374 			continue;
1375 
1376 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1377 	}
1378 	spin_unlock(&pr_tmpl->registration_lock);
1379 }
1380 
1381 void core_scsi3_free_all_registrations(
1382 	struct se_device *dev)
1383 {
1384 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1385 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1386 
1387 	spin_lock(&dev->dev_reservation_lock);
1388 	pr_res_holder = dev->dev_pr_res_holder;
1389 	if (pr_res_holder != NULL) {
1390 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1391 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1392 						  pr_res_holder, 0, 0);
1393 	}
1394 	spin_unlock(&dev->dev_reservation_lock);
1395 
1396 	spin_lock(&pr_tmpl->registration_lock);
1397 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1398 			&pr_tmpl->registration_list, pr_reg_list) {
1399 
1400 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1401 	}
1402 	spin_unlock(&pr_tmpl->registration_lock);
1403 
1404 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1405 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1406 				pr_reg_aptpl_list) {
1407 		list_del(&pr_reg->pr_reg_aptpl_list);
1408 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1409 	}
1410 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1411 }
1412 
1413 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1414 {
1415 	return target_depend_item(&tpg->tpg_group.cg_item);
1416 }
1417 
1418 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1419 {
1420 	target_undepend_item(&tpg->tpg_group.cg_item);
1421 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1422 }
1423 
1424 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1425 {
1426 	if (nacl->dynamic_node_acl)
1427 		return 0;
1428 	return target_depend_item(&nacl->acl_group.cg_item);
1429 }
1430 
1431 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1432 {
1433 	if (!nacl->dynamic_node_acl)
1434 		target_undepend_item(&nacl->acl_group.cg_item);
1435 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1436 }
1437 
1438 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1439 {
1440 	/*
1441 	 * For nacl->dynamic_node_acl=1
1442 	 */
1443 	if (!se_deve->se_lun_acl)
1444 		return 0;
1445 
1446 	return target_depend_item(&se_deve->se_lun_acl->se_lun_group.cg_item);
1447 }
1448 
1449 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1450 {
1451 	/*
1452 	 * For nacl->dynamic_node_acl=1
1453 	 */
1454 	if (!se_deve->se_lun_acl) {
1455 		kref_put(&se_deve->pr_kref, target_pr_kref_release);
1456 		return;
1457 	}
1458 
1459 	target_undepend_item(&se_deve->se_lun_acl->se_lun_group.cg_item);
1460 	kref_put(&se_deve->pr_kref, target_pr_kref_release);
1461 }
1462 
1463 static sense_reason_t
1464 core_scsi3_decode_spec_i_port(
1465 	struct se_cmd *cmd,
1466 	struct se_portal_group *tpg,
1467 	unsigned char *l_isid,
1468 	u64 sa_res_key,
1469 	int all_tg_pt,
1470 	int aptpl)
1471 {
1472 	struct se_device *dev = cmd->se_dev;
1473 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1474 	struct se_session *se_sess = cmd->se_sess;
1475 	struct se_node_acl *dest_node_acl = NULL;
1476 	struct se_dev_entry *dest_se_deve = NULL;
1477 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1478 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1479 	LIST_HEAD(tid_dest_list);
1480 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1481 	unsigned char *buf, *ptr, proto_ident;
1482 	unsigned char i_str[TRANSPORT_IQN_LEN];
1483 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN];
1484 	sense_reason_t ret;
1485 	u32 tpdl, tid_len = 0;
1486 	u32 dest_rtpi = 0;
1487 	bool tid_found;
1488 
1489 	/*
1490 	 * Allocate a struct pr_transport_id_holder and setup the
1491 	 * local_node_acl pointer and add to struct list_head tid_dest_list
1492 	 * for add registration processing in the loop of tid_dest_list below.
1493 	 */
1494 	tidh_new = kzalloc_obj(struct pr_transport_id_holder);
1495 	if (!tidh_new) {
1496 		pr_err("Unable to allocate tidh_new\n");
1497 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1498 	}
1499 	INIT_LIST_HEAD(&tidh_new->dest_list);
1500 	tidh_new->dest_tpg = tpg;
1501 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1502 
1503 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1504 				se_sess->se_node_acl, cmd->se_lun,
1505 				NULL, cmd->orig_fe_lun, l_isid,
1506 				sa_res_key, all_tg_pt, aptpl);
1507 	if (!local_pr_reg) {
1508 		kfree(tidh_new);
1509 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1510 	}
1511 
1512 	if (core_scsi3_lunacl_depend_item(local_pr_reg->pr_reg_deve)) {
1513 		kfree(tidh_new);
1514 		kref_put(&local_pr_reg->pr_reg_deve->pr_kref,
1515 			 target_pr_kref_release);
1516 		kmem_cache_free(t10_pr_reg_cache, local_pr_reg);
1517 		return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1518 	}
1519 
1520 	tidh_new->dest_pr_reg = local_pr_reg;
1521 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1522 
1523 	if (cmd->data_length < 28) {
1524 		pr_warn("SPC-PR: Received PR OUT parameter list"
1525 			" length too small: %u\n", cmd->data_length);
1526 		ret = TCM_INVALID_PARAMETER_LIST;
1527 		goto out;
1528 	}
1529 
1530 	buf = transport_kmap_data_sg(cmd);
1531 	if (!buf) {
1532 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1533 		goto out;
1534 	}
1535 
1536 	/*
1537 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1538 	 * first extract TransportID Parameter Data Length, and make sure
1539 	 * the value matches up to the SCSI expected data transfer length.
1540 	 */
1541 	tpdl = get_unaligned_be32(&buf[24]);
1542 
1543 	if ((tpdl + 28) != cmd->data_length) {
1544 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1545 			" does not equal CDB data_length: %u\n", tpdl,
1546 			cmd->data_length);
1547 		ret = TCM_INVALID_PARAMETER_LIST;
1548 		goto out_unmap;
1549 	}
1550 	/*
1551 	 * Start processing the received transport IDs using the
1552 	 * receiving I_T Nexus portal's fabric dependent methods to
1553 	 * obtain the SCSI Initiator Port/Device Identifiers.
1554 	 */
1555 	ptr = &buf[28];
1556 
1557 	while (tpdl > 0) {
1558 		struct se_lun *dest_lun, *tmp_lun;
1559 
1560 		proto_ident = (ptr[0] & 0x0f);
1561 		dest_tpg = NULL;
1562 
1563 		spin_lock(&dev->se_port_lock);
1564 		list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
1565 			tmp_tpg = tmp_lun->lun_tpg;
1566 
1567 			/*
1568 			 * Look for the matching proto_ident provided by
1569 			 * the received TransportID
1570 			 */
1571 			if (tmp_tpg->proto_id != proto_ident)
1572 				continue;
1573 			dest_rtpi = tmp_lun->lun_tpg->tpg_rtpi;
1574 
1575 			iport_ptr = NULL;
1576 			tid_found = target_parse_pr_out_transport_id(tmp_tpg,
1577 					ptr, tpdl, &tid_len, &iport_ptr, i_str);
1578 			if (!tid_found)
1579 				continue;
1580 			/*
1581 			 * Determine if this SCSI device server requires that
1582 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1583 			 * for fabric modules (iSCSI) requiring them.
1584 			 */
1585 			if (tpg->se_tpg_tfo->sess_get_initiator_sid &&
1586 			    dev->dev_attrib.enforce_pr_isids &&
1587 			    !iport_ptr) {
1588 				pr_warn("SPC-PR: enforce_pr_isids is set but a isid has not been sent in the SPEC_I_PT data for %s.",
1589 					i_str);
1590 				ret = TCM_INVALID_PARAMETER_LIST;
1591 				spin_unlock(&dev->se_port_lock);
1592 				goto out_unmap;
1593 			}
1594 
1595 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1596 			spin_unlock(&dev->se_port_lock);
1597 
1598 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1599 				pr_err(" core_scsi3_tpg_depend_item()"
1600 					" for tmp_tpg\n");
1601 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1602 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1603 				goto out_unmap;
1604 			}
1605 			/*
1606 			 * Locate the destination initiator ACL to be registered
1607 			 * from the decoded fabric module specific TransportID
1608 			 * at *i_str.
1609 			 */
1610 			mutex_lock(&tmp_tpg->acl_node_mutex);
1611 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1612 						tmp_tpg, i_str);
1613 			if (dest_node_acl)
1614 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1615 			mutex_unlock(&tmp_tpg->acl_node_mutex);
1616 
1617 			if (!dest_node_acl) {
1618 				core_scsi3_tpg_undepend_item(tmp_tpg);
1619 				spin_lock(&dev->se_port_lock);
1620 				continue;
1621 			}
1622 
1623 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1624 				pr_err("configfs_depend_item() failed"
1625 					" for dest_node_acl->acl_group\n");
1626 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1627 				core_scsi3_tpg_undepend_item(tmp_tpg);
1628 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1629 				goto out_unmap;
1630 			}
1631 
1632 			dest_tpg = tmp_tpg;
1633 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s Port RTPI: %u\n",
1634 				dest_tpg->se_tpg_tfo->fabric_name,
1635 				dest_node_acl->initiatorname, dest_rtpi);
1636 
1637 			spin_lock(&dev->se_port_lock);
1638 			break;
1639 		}
1640 		spin_unlock(&dev->se_port_lock);
1641 
1642 		if (!dest_tpg) {
1643 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1644 					" dest_tpg\n");
1645 			ret = TCM_INVALID_PARAMETER_LIST;
1646 			goto out_unmap;
1647 		}
1648 
1649 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1650 			" tid_len: %d for %s + %s\n",
1651 			dest_tpg->se_tpg_tfo->fabric_name, cmd->data_length,
1652 			tpdl, tid_len, i_str, iport_ptr);
1653 
1654 		if (tid_len > tpdl) {
1655 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1656 				" %u for Transport ID: %s\n", tid_len, ptr);
1657 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1658 			core_scsi3_tpg_undepend_item(dest_tpg);
1659 			ret = TCM_INVALID_PARAMETER_LIST;
1660 			goto out_unmap;
1661 		}
1662 		/*
1663 		 * Locate the desintation struct se_dev_entry pointer for matching
1664 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1665 		 * Target Port.
1666 		 */
1667 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1668 					dest_rtpi);
1669 		if (!dest_se_deve) {
1670 			pr_err("Unable to locate %s dest_se_deve from destination RTPI: %u\n",
1671 				dest_tpg->se_tpg_tfo->fabric_name,
1672 				dest_rtpi);
1673 
1674 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1675 			core_scsi3_tpg_undepend_item(dest_tpg);
1676 			ret = TCM_INVALID_PARAMETER_LIST;
1677 			goto out_unmap;
1678 		}
1679 
1680 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1681 			pr_err("core_scsi3_lunacl_depend_item()"
1682 					" failed\n");
1683 			kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
1684 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1685 			core_scsi3_tpg_undepend_item(dest_tpg);
1686 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1687 			goto out_unmap;
1688 		}
1689 
1690 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1691 			" dest_se_deve mapped_lun: %llu\n",
1692 			dest_tpg->se_tpg_tfo->fabric_name,
1693 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1694 
1695 		/*
1696 		 * Skip any TransportIDs that already have a registration for
1697 		 * this target port.
1698 		 */
1699 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1700 					iport_ptr);
1701 		if (pr_reg_e) {
1702 			core_scsi3_put_pr_reg(pr_reg_e);
1703 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1704 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1705 			core_scsi3_tpg_undepend_item(dest_tpg);
1706 			ptr += tid_len;
1707 			tpdl -= tid_len;
1708 			tid_len = 0;
1709 			continue;
1710 		}
1711 		/*
1712 		 * Allocate a struct pr_transport_id_holder and setup
1713 		 * the dest_node_acl and dest_se_deve pointers for the
1714 		 * loop below.
1715 		 */
1716 		tidh_new = kzalloc_obj(struct pr_transport_id_holder);
1717 		if (!tidh_new) {
1718 			pr_err("Unable to allocate tidh_new\n");
1719 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1720 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1721 			core_scsi3_tpg_undepend_item(dest_tpg);
1722 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1723 			goto out_unmap;
1724 		}
1725 		INIT_LIST_HEAD(&tidh_new->dest_list);
1726 		tidh_new->dest_tpg = dest_tpg;
1727 		tidh_new->dest_node_acl = dest_node_acl;
1728 		tidh_new->dest_se_deve = dest_se_deve;
1729 
1730 		/*
1731 		 * Allocate, but do NOT add the registration for the
1732 		 * TransportID referenced SCSI Initiator port.  This
1733 		 * done because of the following from spc4r17 in section
1734 		 * 6.14.3 wrt SPEC_I_PT:
1735 		 *
1736 		 * "If a registration fails for any initiator port (e.g., if th
1737 		 * logical unit does not have enough resources available to
1738 		 * hold the registration information), no registrations shall be
1739 		 * made, and the command shall be terminated with
1740 		 * CHECK CONDITION status."
1741 		 *
1742 		 * That means we call __core_scsi3_alloc_registration() here,
1743 		 * and then call __core_scsi3_add_registration() in the
1744 		 * 2nd loop which will never fail.
1745 		 */
1746 		dest_lun = dest_se_deve->se_lun;
1747 
1748 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1749 					dest_node_acl, dest_lun, dest_se_deve,
1750 					dest_se_deve->mapped_lun, iport_ptr,
1751 					sa_res_key, all_tg_pt, aptpl);
1752 		if (!dest_pr_reg) {
1753 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1754 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1755 			core_scsi3_tpg_undepend_item(dest_tpg);
1756 			kfree(tidh_new);
1757 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
1758 			goto out_unmap;
1759 		}
1760 		tidh_new->dest_pr_reg = dest_pr_reg;
1761 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1762 
1763 		ptr += tid_len;
1764 		tpdl -= tid_len;
1765 		tid_len = 0;
1766 
1767 	}
1768 
1769 	transport_kunmap_data_sg(cmd);
1770 
1771 	/*
1772 	 * Go ahead and create a registrations from tid_dest_list for the
1773 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1774 	 * and dest_se_deve.
1775 	 *
1776 	 * The SA Reservation Key from the PROUT is set for the
1777 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1778 	 * means that the TransportID Initiator port will be
1779 	 * registered on all of the target ports in the SCSI target device
1780 	 * ALL_TG_PT=0 means the registration will only be for the
1781 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1782 	 * was received.
1783 	 */
1784 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1785 		dest_tpg = tidh->dest_tpg;
1786 		dest_node_acl = tidh->dest_node_acl;
1787 		dest_se_deve = tidh->dest_se_deve;
1788 		dest_pr_reg = tidh->dest_pr_reg;
1789 
1790 		list_del(&tidh->dest_list);
1791 		kfree(tidh);
1792 
1793 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1794 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1795 
1796 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1797 					dest_pr_reg, 0, 0);
1798 
1799 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1800 			" registered Transport ID for Node: %s%s Mapped LUN:"
1801 			" %llu\n", dest_tpg->se_tpg_tfo->fabric_name,
1802 			dest_node_acl->initiatorname, i_buf, (dest_se_deve) ?
1803 			dest_se_deve->mapped_lun : 0);
1804 
1805 		if (dest_pr_reg == local_pr_reg)
1806 			continue;
1807 
1808 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1809 		core_scsi3_tpg_undepend_item(dest_tpg);
1810 	}
1811 
1812 	return 0;
1813 out_unmap:
1814 	transport_kunmap_data_sg(cmd);
1815 out:
1816 	/*
1817 	 * For the failure case, release everything from tid_dest_list
1818 	 * including *dest_pr_reg and the configfs dependances..
1819 	 */
1820 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1821 		bool is_local = false;
1822 
1823 		dest_tpg = tidh->dest_tpg;
1824 		dest_node_acl = tidh->dest_node_acl;
1825 		dest_se_deve = tidh->dest_se_deve;
1826 		dest_pr_reg = tidh->dest_pr_reg;
1827 
1828 		if (dest_pr_reg == local_pr_reg)
1829 			is_local = true;
1830 
1831 		list_del(&tidh->dest_list);
1832 		kfree(tidh);
1833 		/*
1834 		 * Release any extra ALL_TG_PT=1 registrations for
1835 		 * the SPEC_I_PT=1 case.
1836 		 */
1837 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1838 				&dest_pr_reg->pr_reg_atp_list,
1839 				pr_reg_atp_mem_list) {
1840 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1841 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1842 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1843 		}
1844 
1845 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1846 
1847 		if (dest_se_deve)
1848 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1849 
1850 		if (is_local)
1851 			continue;
1852 
1853 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1854 		core_scsi3_tpg_undepend_item(dest_tpg);
1855 	}
1856 	return ret;
1857 }
1858 
1859 static int core_scsi3_update_aptpl_buf(
1860 	struct se_device *dev,
1861 	unsigned char *buf,
1862 	u32 pr_aptpl_buf_len)
1863 {
1864 	struct se_portal_group *tpg;
1865 	struct t10_pr_registration *pr_reg;
1866 	unsigned char tmp[512], isid_buf[32];
1867 	ssize_t len = 0;
1868 	int reg_count = 0;
1869 	int ret = 0;
1870 
1871 	spin_lock(&dev->dev_reservation_lock);
1872 	spin_lock(&dev->t10_pr.registration_lock);
1873 	/*
1874 	 * Walk the registration list..
1875 	 */
1876 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1877 			pr_reg_list) {
1878 
1879 		tmp[0] = '\0';
1880 		isid_buf[0] = '\0';
1881 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1882 		/*
1883 		 * Write out any ISID value to APTPL metadata that was included
1884 		 * in the original registration.
1885 		 */
1886 		if (pr_reg->isid_present_at_reg)
1887 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1888 					pr_reg->pr_reg_isid);
1889 		/*
1890 		 * Include special metadata if the pr_reg matches the
1891 		 * reservation holder.
1892 		 */
1893 		if (dev->dev_pr_res_holder == pr_reg) {
1894 			snprintf(tmp, 512, "PR_REG_START: %d"
1895 				"\ninitiator_fabric=%s\n"
1896 				"initiator_node=%s\n%s"
1897 				"sa_res_key=%llu\n"
1898 				"res_holder=1\nres_type=%02x\n"
1899 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1900 				"mapped_lun=%llu\n", reg_count,
1901 				tpg->se_tpg_tfo->fabric_name,
1902 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1903 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1904 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1905 				pr_reg->pr_res_mapped_lun);
1906 		} else {
1907 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1908 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1909 				"sa_res_key=%llu\nres_holder=0\n"
1910 				"res_all_tg_pt=%d\nmapped_lun=%llu\n",
1911 				reg_count, tpg->se_tpg_tfo->fabric_name,
1912 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1913 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1914 				pr_reg->pr_res_mapped_lun);
1915 		}
1916 
1917 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1918 			pr_err("Unable to update renaming APTPL metadata,"
1919 			       " reallocating larger buffer\n");
1920 			ret = -EMSGSIZE;
1921 			goto out;
1922 		}
1923 		len += sprintf(buf+len, "%s", tmp);
1924 
1925 		/*
1926 		 * Include information about the associated SCSI target port.
1927 		 */
1928 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1929 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%llu\nPR_REG_END:"
1930 			" %d\n", tpg->se_tpg_tfo->fabric_name,
1931 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1932 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1933 			pr_reg->tg_pt_sep_rtpi, pr_reg->pr_aptpl_target_lun,
1934 			reg_count);
1935 
1936 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1937 			pr_err("Unable to update renaming APTPL metadata,"
1938 			       " reallocating larger buffer\n");
1939 			ret = -EMSGSIZE;
1940 			goto out;
1941 		}
1942 		len += sprintf(buf+len, "%s", tmp);
1943 		reg_count++;
1944 	}
1945 
1946 	if (!reg_count)
1947 		len += sprintf(buf+len, "No Registrations or Reservations");
1948 
1949 out:
1950 	spin_unlock(&dev->t10_pr.registration_lock);
1951 	spin_unlock(&dev->dev_reservation_lock);
1952 
1953 	return ret;
1954 }
1955 
1956 static int __core_scsi3_write_aptpl_to_file(
1957 	struct se_device *dev,
1958 	unsigned char *buf)
1959 {
1960 	struct t10_wwn *wwn = &dev->t10_wwn;
1961 	struct file *file;
1962 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1963 	char *path;
1964 	u32 pr_aptpl_buf_len;
1965 	int ret;
1966 	loff_t pos = 0;
1967 
1968 	path = kasprintf(GFP_KERNEL, "%s/pr/aptpl_%s", db_root,
1969 			&wwn->unit_serial[0]);
1970 	if (!path)
1971 		return -ENOMEM;
1972 
1973 	scoped_with_init_fs()
1974 		file = filp_open(path, flags, 0600);
1975 	if (IS_ERR(file)) {
1976 		pr_err("filp_open(%s) for APTPL metadata"
1977 			" failed\n", path);
1978 		kfree(path);
1979 		return PTR_ERR(file);
1980 	}
1981 
1982 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1983 
1984 	ret = kernel_write(file, buf, pr_aptpl_buf_len, &pos);
1985 
1986 	if (ret < 0)
1987 		pr_debug("Error writing APTPL metadata file: %s\n", path);
1988 	fput(file);
1989 	kfree(path);
1990 
1991 	return (ret < 0) ? -EIO : 0;
1992 }
1993 
1994 /*
1995  * Clear the APTPL metadata if APTPL has been disabled, otherwise
1996  * write out the updated metadata to struct file for this SCSI device.
1997  */
1998 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
1999 {
2000 	unsigned char *buf;
2001 	int rc, len = PR_APTPL_BUF_LEN;
2002 
2003 	if (!aptpl) {
2004 		char *null_buf = "No Registrations or Reservations\n";
2005 
2006 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
2007 		dev->t10_pr.pr_aptpl_active = 0;
2008 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
2009 
2010 		if (rc)
2011 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2012 
2013 		return 0;
2014 	}
2015 retry:
2016 	buf = vzalloc(len);
2017 	if (!buf)
2018 		return TCM_OUT_OF_RESOURCES;
2019 
2020 	rc = core_scsi3_update_aptpl_buf(dev, buf, len);
2021 	if (rc < 0) {
2022 		vfree(buf);
2023 		len *= 2;
2024 		goto retry;
2025 	}
2026 
2027 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
2028 	if (rc != 0) {
2029 		pr_err("SPC-3 PR: Could not update APTPL\n");
2030 		vfree(buf);
2031 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2032 	}
2033 	dev->t10_pr.pr_aptpl_active = 1;
2034 	vfree(buf);
2035 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
2036 	return 0;
2037 }
2038 
2039 static sense_reason_t
2040 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2041 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
2042 {
2043 	struct se_session *se_sess = cmd->se_sess;
2044 	struct se_device *dev = cmd->se_dev;
2045 	struct se_lun *se_lun = cmd->se_lun;
2046 	struct se_portal_group *se_tpg;
2047 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
2048 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2049 	unsigned char isid_buf[PR_REG_ISID_LEN] = { };
2050 	unsigned char *isid_ptr = NULL;
2051 	sense_reason_t ret = TCM_NO_SENSE;
2052 	int pr_holder = 0, type;
2053 
2054 	if (!se_sess || !se_lun) {
2055 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2056 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2057 	}
2058 	se_tpg = se_sess->se_tpg;
2059 
2060 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2061 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2062 				PR_REG_ISID_LEN);
2063 		isid_ptr = &isid_buf[0];
2064 	}
2065 	/*
2066 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2067 	 */
2068 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2069 	if (!pr_reg) {
2070 		if (res_key) {
2071 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2072 				" for SA REGISTER, returning CONFLICT\n");
2073 			return TCM_RESERVATION_CONFLICT;
2074 		}
2075 		/*
2076 		 * Do nothing but return GOOD status.
2077 		 */
2078 		if (!sa_res_key)
2079 			return 0;
2080 
2081 		if (!spec_i_pt) {
2082 			/*
2083 			 * Perform the Service Action REGISTER on the Initiator
2084 			 * Port Endpoint that the PRO was received from on the
2085 			 * Logical Unit of the SCSI device server.
2086 			 */
2087 			if (core_scsi3_alloc_registration(cmd->se_dev,
2088 					se_sess->se_node_acl, cmd->se_lun,
2089 					NULL, cmd->orig_fe_lun, isid_ptr,
2090 					sa_res_key, all_tg_pt, aptpl,
2091 					register_type, 0)) {
2092 				pr_err("Unable to allocate"
2093 					" struct t10_pr_registration\n");
2094 				return TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
2095 			}
2096 		} else {
2097 			/*
2098 			 * Register both the Initiator port that received
2099 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2100 			 * TransportID from Parameter list and loop through
2101 			 * fabric dependent parameter list while calling
2102 			 * logic from of core_scsi3_alloc_registration() for
2103 			 * each TransportID provided SCSI Initiator Port/Device
2104 			 */
2105 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2106 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2107 			if (ret != 0)
2108 				return ret;
2109 		}
2110 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2111 	}
2112 
2113 	/* ok, existing registration */
2114 
2115 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2116 		pr_err("SPC-3 PR REGISTER: Received"
2117 		       " res_key: 0x%016Lx does not match"
2118 		       " existing SA REGISTER res_key:"
2119 		       " 0x%016Lx\n", res_key,
2120 		       pr_reg->pr_res_key);
2121 		ret = TCM_RESERVATION_CONFLICT;
2122 		goto out;
2123 	}
2124 
2125 	if (spec_i_pt) {
2126 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2127 			" set on a registered nexus\n");
2128 		ret = TCM_INVALID_PARAMETER_LIST;
2129 		goto out;
2130 	}
2131 
2132 	/*
2133 	 * An existing ALL_TG_PT=1 registration being released
2134 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2135 	 */
2136 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2137 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2138 			" registration exists, but ALL_TG_PT=1 bit not"
2139 			" present in received PROUT\n");
2140 		ret = TCM_INVALID_CDB_FIELD;
2141 		goto out;
2142 	}
2143 
2144 	/*
2145 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2146 	 */
2147 	if (sa_res_key) {
2148 		/*
2149 		 * Increment PRgeneration counter for struct se_device"
2150 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2151 		 * READ_KEYS service action.
2152 		 */
2153 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2154 		pr_reg->pr_res_key = sa_res_key;
2155 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2156 			 " Key for %s to: 0x%016Lx PRgeneration:"
2157 			 " 0x%08x\n", cmd->se_tfo->fabric_name,
2158 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2159 			 pr_reg->pr_reg_nacl->initiatorname,
2160 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2161 
2162 	} else {
2163 		/*
2164 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2165 		 */
2166 		type = pr_reg->pr_res_type;
2167 		pr_holder = core_scsi3_check_implicit_release(cmd->se_dev,
2168 							      pr_reg);
2169 		if (pr_holder < 0) {
2170 			ret = TCM_RESERVATION_CONFLICT;
2171 			goto out;
2172 		}
2173 
2174 		spin_lock(&pr_tmpl->registration_lock);
2175 		/*
2176 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2177 		 * and matching pr_res_key.
2178 		 */
2179 		if (pr_reg->pr_reg_all_tg_pt) {
2180 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2181 					&pr_tmpl->registration_list,
2182 					pr_reg_list) {
2183 
2184 				if (!pr_reg_p->pr_reg_all_tg_pt)
2185 					continue;
2186 				if (pr_reg_p->pr_res_key != res_key)
2187 					continue;
2188 				if (pr_reg == pr_reg_p)
2189 					continue;
2190 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2191 					   pr_reg_p->pr_reg_nacl->initiatorname))
2192 					continue;
2193 
2194 				__core_scsi3_free_registration(dev,
2195 						pr_reg_p, NULL, 0);
2196 			}
2197 		}
2198 
2199 		/*
2200 		 * Release the calling I_T Nexus registration now..
2201 		 */
2202 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2203 		pr_reg = NULL;
2204 
2205 		/*
2206 		 * From spc4r17, section 5.7.11.3 Unregistering
2207 		 *
2208 		 * If the persistent reservation is a registrants only
2209 		 * type, the device server shall establish a unit
2210 		 * attention condition for the initiator port associated
2211 		 * with every registered I_T nexus except for the I_T
2212 		 * nexus on which the PERSISTENT RESERVE OUT command was
2213 		 * received, with the additional sense code set to
2214 		 * RESERVATIONS RELEASED.
2215 		 */
2216 		if (pr_holder &&
2217 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2218 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2219 			list_for_each_entry(pr_reg_p,
2220 					&pr_tmpl->registration_list,
2221 					pr_reg_list) {
2222 
2223 				target_ua_allocate_lun(
2224 					pr_reg_p->pr_reg_nacl,
2225 					pr_reg_p->pr_res_mapped_lun,
2226 					0x2A,
2227 					ASCQ_2AH_RESERVATIONS_RELEASED);
2228 			}
2229 		}
2230 
2231 		spin_unlock(&pr_tmpl->registration_lock);
2232 	}
2233 
2234 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2235 
2236 out:
2237 	if (pr_reg)
2238 		core_scsi3_put_pr_reg(pr_reg);
2239 	return ret;
2240 }
2241 
2242 unsigned char *core_scsi3_pr_dump_type(int type)
2243 {
2244 	switch (type) {
2245 	case PR_TYPE_WRITE_EXCLUSIVE:
2246 		return "Write Exclusive Access";
2247 	case PR_TYPE_EXCLUSIVE_ACCESS:
2248 		return "Exclusive Access";
2249 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2250 		return "Write Exclusive Access, Registrants Only";
2251 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2252 		return "Exclusive Access, Registrants Only";
2253 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2254 		return "Write Exclusive Access, All Registrants";
2255 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2256 		return "Exclusive Access, All Registrants";
2257 	default:
2258 		break;
2259 	}
2260 
2261 	return "Unknown SPC-3 PR Type";
2262 }
2263 
2264 static sense_reason_t
2265 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2266 {
2267 	struct se_device *dev = cmd->se_dev;
2268 	struct se_session *se_sess = cmd->se_sess;
2269 	struct se_lun *se_lun = cmd->se_lun;
2270 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2271 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2272 	char i_buf[PR_REG_ISID_ID_LEN] = { };
2273 	sense_reason_t ret;
2274 
2275 	if (!se_sess || !se_lun) {
2276 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2277 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2278 	}
2279 	/*
2280 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2281 	 */
2282 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2283 				se_sess);
2284 	if (!pr_reg) {
2285 		pr_err("SPC-3 PR: Unable to locate"
2286 			" PR_REGISTERED *pr_reg for RESERVE\n");
2287 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2288 	}
2289 	/*
2290 	 * From spc4r17 Section 5.7.9: Reserving:
2291 	 *
2292 	 * An application client creates a persistent reservation by issuing
2293 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2294 	 * a registered I_T nexus with the following parameters:
2295 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2296 	 * 	 registered with the logical unit for the I_T nexus; and
2297 	 */
2298 	if (res_key != pr_reg->pr_res_key) {
2299 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2300 			" does not match existing SA REGISTER res_key:"
2301 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2302 		ret = TCM_RESERVATION_CONFLICT;
2303 		goto out_put_pr_reg;
2304 	}
2305 	/*
2306 	 * From spc4r17 Section 5.7.9: Reserving:
2307 	 *
2308 	 * From above:
2309 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2310 	 *     being created.
2311 	 *
2312 	 * Only one persistent reservation is allowed at a time per logical unit
2313 	 * and that persistent reservation has a scope of LU_SCOPE.
2314 	 */
2315 	if (scope != PR_SCOPE_LU_SCOPE) {
2316 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2317 		ret = TCM_INVALID_PARAMETER_LIST;
2318 		goto out_put_pr_reg;
2319 	}
2320 	/*
2321 	 * See if we have an existing PR reservation holder pointer at
2322 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2323 	 * *pr_res_holder.
2324 	 */
2325 	spin_lock(&dev->dev_reservation_lock);
2326 	pr_res_holder = dev->dev_pr_res_holder;
2327 	if (pr_res_holder) {
2328 		/*
2329 		 * From spc4r17 Section 5.7.9: Reserving:
2330 		 *
2331 		 * If the device server receives a PERSISTENT RESERVE OUT
2332 		 * command from an I_T nexus other than a persistent reservation
2333 		 * holder (see 5.7.10) that attempts to create a persistent
2334 		 * reservation when a persistent reservation already exists for
2335 		 * the logical unit, then the command shall be completed with
2336 		 * RESERVATION CONFLICT status.
2337 		 */
2338 		if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2339 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2340 			pr_err("SPC-3 PR: Attempted RESERVE from"
2341 				" [%s]: %s while reservation already held by"
2342 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2343 				cmd->se_tfo->fabric_name,
2344 				se_sess->se_node_acl->initiatorname,
2345 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2346 				pr_res_holder->pr_reg_nacl->initiatorname);
2347 
2348 			spin_unlock(&dev->dev_reservation_lock);
2349 			ret = TCM_RESERVATION_CONFLICT;
2350 			goto out_put_pr_reg;
2351 		}
2352 		/*
2353 		 * From spc4r17 Section 5.7.9: Reserving:
2354 		 *
2355 		 * If a persistent reservation holder attempts to modify the
2356 		 * type or scope of an existing persistent reservation, the
2357 		 * command shall be completed with RESERVATION CONFLICT status.
2358 		 */
2359 		if ((pr_res_holder->pr_res_type != type) ||
2360 		    (pr_res_holder->pr_res_scope != scope)) {
2361 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2362 			pr_err("SPC-3 PR: Attempted RESERVE from"
2363 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2364 				" while reservation already held by [%s]: %s,"
2365 				" returning RESERVATION_CONFLICT\n",
2366 				cmd->se_tfo->fabric_name,
2367 				se_sess->se_node_acl->initiatorname,
2368 				pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2369 				pr_res_holder->pr_reg_nacl->initiatorname);
2370 
2371 			spin_unlock(&dev->dev_reservation_lock);
2372 			ret = TCM_RESERVATION_CONFLICT;
2373 			goto out_put_pr_reg;
2374 		}
2375 		/*
2376 		 * From spc4r17 Section 5.7.9: Reserving:
2377 		 *
2378 		 * If the device server receives a PERSISTENT RESERVE OUT
2379 		 * command with RESERVE service action where the TYPE field and
2380 		 * the SCOPE field contain the same values as the existing type
2381 		 * and scope from a persistent reservation holder, it shall not
2382 		 * make any change to the existing persistent reservation and
2383 		 * shall completethe command with GOOD status.
2384 		 */
2385 		spin_unlock(&dev->dev_reservation_lock);
2386 		ret = 0;
2387 		goto out_put_pr_reg;
2388 	}
2389 	/*
2390 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2391 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2392 	 */
2393 	pr_reg->pr_res_scope = scope;
2394 	pr_reg->pr_res_type = type;
2395 	pr_reg->pr_res_holder = 1;
2396 	dev->dev_pr_res_holder = pr_reg;
2397 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2398 
2399 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2400 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2401 		cmd->se_tfo->fabric_name, core_scsi3_pr_dump_type(type),
2402 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2403 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2404 			cmd->se_tfo->fabric_name,
2405 			se_sess->se_node_acl->initiatorname,
2406 			i_buf);
2407 	spin_unlock(&dev->dev_reservation_lock);
2408 
2409 	if (pr_tmpl->pr_aptpl_active)
2410 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2411 
2412 	ret = 0;
2413 out_put_pr_reg:
2414 	core_scsi3_put_pr_reg(pr_reg);
2415 	return ret;
2416 }
2417 
2418 static sense_reason_t
2419 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2420 		u64 res_key)
2421 {
2422 	switch (type) {
2423 	case PR_TYPE_WRITE_EXCLUSIVE:
2424 	case PR_TYPE_EXCLUSIVE_ACCESS:
2425 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2426 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2427 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2428 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2429 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2430 	default:
2431 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2432 			" 0x%02x\n", type);
2433 		return TCM_INVALID_CDB_FIELD;
2434 	}
2435 }
2436 
2437 static void __core_scsi3_complete_pro_release(
2438 	struct se_device *dev,
2439 	struct se_node_acl *se_nacl,
2440 	struct t10_pr_registration *pr_reg,
2441 	int explicit,
2442 	int unreg)
2443 {
2444 	const struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2445 	char i_buf[PR_REG_ISID_ID_LEN] = { };
2446 	int pr_res_type = 0, pr_res_scope = 0;
2447 
2448 	lockdep_assert_held(&dev->dev_reservation_lock);
2449 
2450 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2451 	/*
2452 	 * Go ahead and release the current PR reservation holder.
2453 	 * If an All Registrants reservation is currently active and
2454 	 * a unregister operation is requested, replace the current
2455 	 * dev_pr_res_holder with another active registration.
2456 	 */
2457 	if (dev->dev_pr_res_holder) {
2458 		pr_res_type = dev->dev_pr_res_holder->pr_res_type;
2459 		pr_res_scope = dev->dev_pr_res_holder->pr_res_scope;
2460 		dev->dev_pr_res_holder->pr_res_type = 0;
2461 		dev->dev_pr_res_holder->pr_res_scope = 0;
2462 		dev->dev_pr_res_holder->pr_res_holder = 0;
2463 		dev->dev_pr_res_holder = NULL;
2464 	}
2465 	if (!unreg)
2466 		goto out;
2467 
2468 	spin_lock(&dev->t10_pr.registration_lock);
2469 	list_del_init(&pr_reg->pr_reg_list);
2470 	/*
2471 	 * If the I_T nexus is a reservation holder, the persistent reservation
2472 	 * is of an all registrants type, and the I_T nexus is the last remaining
2473 	 * registered I_T nexus, then the device server shall also release the
2474 	 * persistent reservation.
2475 	 */
2476 	if (!list_empty(&dev->t10_pr.registration_list) &&
2477 	    ((pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2478 	     (pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))) {
2479 		dev->dev_pr_res_holder =
2480 			list_entry(dev->t10_pr.registration_list.next,
2481 				   struct t10_pr_registration, pr_reg_list);
2482 		dev->dev_pr_res_holder->pr_res_type = pr_res_type;
2483 		dev->dev_pr_res_holder->pr_res_scope = pr_res_scope;
2484 		dev->dev_pr_res_holder->pr_res_holder = 1;
2485 	}
2486 	spin_unlock(&dev->t10_pr.registration_lock);
2487 out:
2488 	if (!dev->dev_pr_res_holder) {
2489 		pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2490 			" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2491 			tfo->fabric_name, (explicit) ? "explicit" :
2492 			"implicit", core_scsi3_pr_dump_type(pr_res_type),
2493 			(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2494 	}
2495 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2496 		tfo->fabric_name, se_nacl->initiatorname,
2497 		i_buf);
2498 	/*
2499 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2500 	 */
2501 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2502 }
2503 
2504 static sense_reason_t
2505 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2506 		u64 res_key)
2507 {
2508 	struct se_device *dev = cmd->se_dev;
2509 	struct se_session *se_sess = cmd->se_sess;
2510 	struct se_lun *se_lun = cmd->se_lun;
2511 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2512 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2513 	sense_reason_t ret = 0;
2514 
2515 	if (!se_sess || !se_lun) {
2516 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2517 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2518 	}
2519 	/*
2520 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2521 	 */
2522 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2523 	if (!pr_reg) {
2524 		pr_err("SPC-3 PR: Unable to locate"
2525 			" PR_REGISTERED *pr_reg for RELEASE\n");
2526 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2527 	}
2528 	/*
2529 	 * From spc4r17 Section 5.7.11.2 Releasing:
2530 	 *
2531 	 * If there is no persistent reservation or in response to a persistent
2532 	 * reservation release request from a registered I_T nexus that is not a
2533 	 * persistent reservation holder (see 5.7.10), the device server shall
2534 	 * do the following:
2535 	 *
2536 	 *     a) Not release the persistent reservation, if any;
2537 	 *     b) Not remove any registrations; and
2538 	 *     c) Complete the command with GOOD status.
2539 	 */
2540 	spin_lock(&dev->dev_reservation_lock);
2541 	pr_res_holder = dev->dev_pr_res_holder;
2542 	if (!pr_res_holder) {
2543 		/*
2544 		 * No persistent reservation, return GOOD status.
2545 		 */
2546 		spin_unlock(&dev->dev_reservation_lock);
2547 		goto out_put_pr_reg;
2548 	}
2549 
2550 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
2551 		/*
2552 		 * Release request from a registered I_T nexus that is not a
2553 		 * persistent reservation holder. return GOOD status.
2554 		 */
2555 		spin_unlock(&dev->dev_reservation_lock);
2556 		goto out_put_pr_reg;
2557 	}
2558 
2559 	/*
2560 	 * From spc4r17 Section 5.7.11.2 Releasing:
2561 	 *
2562 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2563 	 * release a persistent reservation.
2564 	 *
2565 	 * An application client releases the persistent reservation by issuing
2566 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2567 	 * an I_T nexus that is a persistent reservation holder with the
2568 	 * following parameters:
2569 	 *
2570 	 *     a) RESERVATION KEY field set to the value of the reservation key
2571 	 *	  that is registered with the logical unit for the I_T nexus;
2572 	 */
2573 	if (res_key != pr_reg->pr_res_key) {
2574 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2575 			" does not match existing SA REGISTER res_key:"
2576 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2577 		spin_unlock(&dev->dev_reservation_lock);
2578 		ret = TCM_RESERVATION_CONFLICT;
2579 		goto out_put_pr_reg;
2580 	}
2581 	/*
2582 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2583 	 *
2584 	 * b) TYPE field and SCOPE field set to match the persistent
2585 	 *    reservation being released.
2586 	 */
2587 	if ((pr_res_holder->pr_res_type != type) ||
2588 	    (pr_res_holder->pr_res_scope != scope)) {
2589 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2590 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2591 			" reservation from [%s]: %s with different TYPE "
2592 			"and/or SCOPE  while reservation already held by"
2593 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2594 			cmd->se_tfo->fabric_name,
2595 			se_sess->se_node_acl->initiatorname,
2596 			pr_res_nacl->se_tpg->se_tpg_tfo->fabric_name,
2597 			pr_res_holder->pr_reg_nacl->initiatorname);
2598 
2599 		spin_unlock(&dev->dev_reservation_lock);
2600 		ret = TCM_RESERVATION_CONFLICT;
2601 		goto out_put_pr_reg;
2602 	}
2603 	/*
2604 	 * In response to a persistent reservation release request from the
2605 	 * persistent reservation holder the device server shall perform a
2606 	 * release by doing the following as an uninterrupted series of actions:
2607 	 * a) Release the persistent reservation;
2608 	 * b) Not remove any registration(s);
2609 	 * c) If the released persistent reservation is a registrants only type
2610 	 * or all registrants type persistent reservation,
2611 	 *    the device server shall establish a unit attention condition for
2612 	 *    the initiator port associated with every regis-
2613 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2614 	 *    RESERVE OUT command with RELEASE service action was received,
2615 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2616 	 * d) If the persistent reservation is of any other type, the device
2617 	 *    server shall not establish a unit attention condition.
2618 	 */
2619 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2620 					  pr_reg, 1, 0);
2621 
2622 	spin_unlock(&dev->dev_reservation_lock);
2623 
2624 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2625 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2626 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2627 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2628 		/*
2629 		 * If no UNIT ATTENTION conditions will be established for
2630 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2631 		 * go ahead and check for APTPL=1 update+write below
2632 		 */
2633 		goto write_aptpl;
2634 	}
2635 
2636 	spin_lock(&pr_tmpl->registration_lock);
2637 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2638 			pr_reg_list) {
2639 		/*
2640 		 * Do not establish a UNIT ATTENTION condition
2641 		 * for the calling I_T Nexus
2642 		 */
2643 		if (pr_reg_p == pr_reg)
2644 			continue;
2645 
2646 		target_ua_allocate_lun(pr_reg_p->pr_reg_nacl,
2647 				pr_reg_p->pr_res_mapped_lun,
2648 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2649 	}
2650 	spin_unlock(&pr_tmpl->registration_lock);
2651 
2652 write_aptpl:
2653 	if (pr_tmpl->pr_aptpl_active)
2654 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2655 
2656 out_put_pr_reg:
2657 	core_scsi3_put_pr_reg(pr_reg);
2658 	return ret;
2659 }
2660 
2661 static sense_reason_t
2662 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2663 {
2664 	struct se_device *dev = cmd->se_dev;
2665 	struct se_node_acl *pr_reg_nacl;
2666 	struct se_session *se_sess = cmd->se_sess;
2667 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2668 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2669 	u64 pr_res_mapped_lun = 0;
2670 	int calling_it_nexus = 0;
2671 	/*
2672 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2673 	 */
2674 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2675 			se_sess->se_node_acl, se_sess);
2676 	if (!pr_reg_n) {
2677 		pr_err("SPC-3 PR: Unable to locate"
2678 			" PR_REGISTERED *pr_reg for CLEAR\n");
2679 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2680 	}
2681 	/*
2682 	 * From spc4r17 section 5.7.11.6, Clearing:
2683 	 *
2684 	 * Any application client may release the persistent reservation and
2685 	 * remove all registrations from a device server by issuing a
2686 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2687 	 * registered I_T nexus with the following parameter:
2688 	 *
2689 	 *	a) RESERVATION KEY field set to the value of the reservation key
2690 	 * 	   that is registered with the logical unit for the I_T nexus.
2691 	 */
2692 	if (res_key != pr_reg_n->pr_res_key) {
2693 		pr_err("SPC-3 PR REGISTER: Received"
2694 			" res_key: 0x%016Lx does not match"
2695 			" existing SA REGISTER res_key:"
2696 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2697 		core_scsi3_put_pr_reg(pr_reg_n);
2698 		return TCM_RESERVATION_CONFLICT;
2699 	}
2700 	/*
2701 	 * a) Release the persistent reservation, if any;
2702 	 */
2703 	spin_lock(&dev->dev_reservation_lock);
2704 	pr_res_holder = dev->dev_pr_res_holder;
2705 	if (pr_res_holder) {
2706 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2707 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2708 						  pr_res_holder, 0, 0);
2709 	}
2710 	spin_unlock(&dev->dev_reservation_lock);
2711 	/*
2712 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2713 	 */
2714 	spin_lock(&pr_tmpl->registration_lock);
2715 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2716 			&pr_tmpl->registration_list, pr_reg_list) {
2717 
2718 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2719 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2720 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2721 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2722 					calling_it_nexus);
2723 		/*
2724 		 * e) Establish a unit attention condition for the initiator
2725 		 *    port associated with every registered I_T nexus other
2726 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2727 		 *    command with CLEAR service action was received, with the
2728 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2729 		 */
2730 		if (!calling_it_nexus)
2731 			target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun,
2732 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2733 	}
2734 	spin_unlock(&pr_tmpl->registration_lock);
2735 
2736 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2737 		cmd->se_tfo->fabric_name);
2738 
2739 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2740 
2741 	core_scsi3_pr_generation(dev);
2742 	return 0;
2743 }
2744 
2745 static void __core_scsi3_complete_pro_preempt(
2746 	struct se_device *dev,
2747 	struct t10_pr_registration *pr_reg,
2748 	struct list_head *preempt_and_abort_list,
2749 	int type,
2750 	int scope,
2751 	enum preempt_type preempt_type)
2752 {
2753 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2754 	const struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2755 	char i_buf[PR_REG_ISID_ID_LEN] = { };
2756 
2757 	lockdep_assert_held(&dev->dev_reservation_lock);
2758 
2759 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2760 	/*
2761 	 * Do an implicit RELEASE of the existing reservation.
2762 	 */
2763 	if (dev->dev_pr_res_holder)
2764 		__core_scsi3_complete_pro_release(dev, nacl,
2765 						  dev->dev_pr_res_holder, 0, 0);
2766 
2767 	dev->dev_pr_res_holder = pr_reg;
2768 	pr_reg->pr_res_holder = 1;
2769 	pr_reg->pr_res_type = type;
2770 	pr_reg->pr_res_scope = scope;
2771 
2772 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2773 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2774 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2775 		core_scsi3_pr_dump_type(type),
2776 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2777 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2778 		tfo->fabric_name, (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2779 		nacl->initiatorname, i_buf);
2780 	/*
2781 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2782 	 * struct t10_pr_registration to the list that will be compared
2783 	 * against received CDBs..
2784 	 */
2785 	if (preempt_and_abort_list)
2786 		list_add_tail(&pr_reg->pr_reg_abort_list,
2787 				preempt_and_abort_list);
2788 }
2789 
2790 static void core_scsi3_release_preempt_and_abort(
2791 	struct list_head *preempt_and_abort_list,
2792 	struct t10_pr_registration *pr_reg_holder)
2793 {
2794 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2795 
2796 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2797 				pr_reg_abort_list) {
2798 
2799 		list_del(&pr_reg->pr_reg_abort_list);
2800 		if (pr_reg_holder == pr_reg)
2801 			continue;
2802 		if (pr_reg->pr_res_holder) {
2803 			pr_warn("pr_reg->pr_res_holder still set\n");
2804 			continue;
2805 		}
2806 
2807 		pr_reg->pr_reg_deve = NULL;
2808 		pr_reg->pr_reg_nacl = NULL;
2809 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2810 	}
2811 }
2812 
2813 static sense_reason_t
2814 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2815 		u64 sa_res_key, enum preempt_type preempt_type)
2816 {
2817 	struct se_device *dev = cmd->se_dev;
2818 	struct se_node_acl *pr_reg_nacl;
2819 	struct se_session *se_sess = cmd->se_sess;
2820 	LIST_HEAD(preempt_and_abort_list);
2821 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2822 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2823 	u64 pr_res_mapped_lun = 0;
2824 	int all_reg = 0, calling_it_nexus = 0;
2825 	bool sa_res_key_unmatched = sa_res_key != 0;
2826 	int prh_type = 0, prh_scope = 0;
2827 
2828 	if (!se_sess)
2829 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2830 
2831 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2832 				se_sess);
2833 	if (!pr_reg_n) {
2834 		pr_err("SPC-3 PR: Unable to locate"
2835 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2836 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2837 		return TCM_RESERVATION_CONFLICT;
2838 	}
2839 	if (pr_reg_n->pr_res_key != res_key) {
2840 		core_scsi3_put_pr_reg(pr_reg_n);
2841 		return TCM_RESERVATION_CONFLICT;
2842 	}
2843 
2844 	spin_lock(&dev->dev_reservation_lock);
2845 	pr_res_holder = dev->dev_pr_res_holder;
2846 	if (pr_res_holder &&
2847 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2848 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2849 		all_reg = 1;
2850 
2851 	if (!all_reg && !sa_res_key) {
2852 		spin_unlock(&dev->dev_reservation_lock);
2853 		core_scsi3_put_pr_reg(pr_reg_n);
2854 		return TCM_INVALID_PARAMETER_LIST;
2855 	}
2856 
2857 	/* Validate TYPE and SCOPE fields if they will be used */
2858 	if (pr_res_holder &&
2859 	    (pr_res_holder->pr_res_key == sa_res_key ||
2860 	     (all_reg && !sa_res_key))) {
2861 		switch (type) {
2862 		case PR_TYPE_WRITE_EXCLUSIVE:
2863 		case PR_TYPE_EXCLUSIVE_ACCESS:
2864 		case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2865 		case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2866 		case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2867 		case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2868 			break;
2869 		default:
2870 			pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
2871 				" Type: 0x%02x\n",
2872 				(preempt_type == PREEMPT_AND_ABORT) ?
2873 				"_AND_ABORT" : "", type);
2874 			spin_unlock(&dev->dev_reservation_lock);
2875 			core_scsi3_put_pr_reg(pr_reg_n);
2876 			return TCM_INVALID_CDB_FIELD;
2877 		}
2878 
2879 		if (scope != PR_SCOPE_LU_SCOPE) {
2880 			pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2881 			spin_unlock(&dev->dev_reservation_lock);
2882 			core_scsi3_put_pr_reg(pr_reg_n);
2883 			return TCM_INVALID_PARAMETER_LIST;
2884 		}
2885 	}
2886 
2887 	/*
2888 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2889 	 *
2890 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2891 	 * persistent reservation holder or there is no persistent reservation
2892 	 * holder (i.e., there is no persistent reservation), then the device
2893 	 * server shall perform a preempt by doing the following in an
2894 	 * uninterrupted series of actions. (See below..)
2895 	 */
2896 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2897 		/*
2898 		 * No existing or SA Reservation Key matching reservations..
2899 		 *
2900 		 * PROUT SA PREEMPT with All Registrant type reservations are
2901 		 * allowed to be processed without a matching SA Reservation Key
2902 		 */
2903 		spin_lock(&pr_tmpl->registration_lock);
2904 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2905 				&pr_tmpl->registration_list, pr_reg_list) {
2906 			/*
2907 			 * Removing of registrations in non all registrants
2908 			 * type reservations without a matching SA reservation
2909 			 * key.
2910 			 *
2911 			 * a) Remove the registrations for all I_T nexuses
2912 			 *    specified by the SERVICE ACTION RESERVATION KEY
2913 			 *    field;
2914 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2915 			 * c) Process tasks as defined in 5.7.1; and
2916 			 * d) Establish a unit attention condition for the
2917 			 *    initiator port associated with every I_T nexus
2918 			 *    that lost its registration other than the I_T
2919 			 *    nexus on which the PERSISTENT RESERVE OUT command
2920 			 *    was received, with the additional sense code set
2921 			 *    to REGISTRATIONS PREEMPTED.
2922 			 */
2923 			if (!all_reg) {
2924 				if (pr_reg->pr_res_key != sa_res_key)
2925 					continue;
2926 				sa_res_key_unmatched = false;
2927 
2928 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2929 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2930 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2931 				__core_scsi3_free_registration(dev, pr_reg,
2932 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2933 						NULL, calling_it_nexus);
2934 			} else {
2935 				/*
2936 				 * Case for any existing all registrants type
2937 				 * reservation, follow logic in spc4r17 section
2938 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2939 				 *
2940 				 * For a ZERO SA Reservation key, release
2941 				 * all other registrations and do an implicit
2942 				 * release of active persistent reservation.
2943 				 *
2944 				 * For a non-ZERO SA Reservation key, only
2945 				 * release the matching reservation key from
2946 				 * registrations.
2947 				 */
2948 				if ((sa_res_key) &&
2949 				     (pr_reg->pr_res_key != sa_res_key))
2950 					continue;
2951 				sa_res_key_unmatched = false;
2952 
2953 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2954 				if (calling_it_nexus)
2955 					continue;
2956 
2957 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2958 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2959 				__core_scsi3_free_registration(dev, pr_reg,
2960 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2961 						NULL, 0);
2962 			}
2963 			if (!calling_it_nexus)
2964 				target_ua_allocate_lun(pr_reg_nacl,
2965 					pr_res_mapped_lun, 0x2A,
2966 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2967 		}
2968 		spin_unlock(&pr_tmpl->registration_lock);
2969 		/*
2970 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2971 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2972 		 * RESERVATION KEY field to a value that does not match any
2973 		 * registered reservation key, then the device server shall
2974 		 * complete the command with RESERVATION CONFLICT status.
2975 		 */
2976 		if (sa_res_key_unmatched) {
2977 			spin_unlock(&dev->dev_reservation_lock);
2978 			core_scsi3_put_pr_reg(pr_reg_n);
2979 			return TCM_RESERVATION_CONFLICT;
2980 		}
2981 		/*
2982 		 * For an existing all registrants type reservation
2983 		 * with a zero SA rservation key, preempt the existing
2984 		 * reservation with the new PR type and scope.
2985 		 */
2986 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2987 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2988 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2989 				type, scope, preempt_type);
2990 		}
2991 
2992 		spin_unlock(&dev->dev_reservation_lock);
2993 
2994 		/*
2995 		 * SPC-4 5.12.11.2.6 Preempting and aborting
2996 		 * The actions described in this subclause shall be performed
2997 		 * for all I_T nexuses that are registered with the non-zero
2998 		 * SERVICE ACTION RESERVATION KEY value, without regard for
2999 		 * whether the preempted I_T nexuses hold the persistent
3000 		 * reservation. If the SERVICE ACTION RESERVATION KEY field is
3001 		 * set to zero and an all registrants persistent reservation is
3002 		 * present, the device server shall abort all commands for all
3003 		 * registered I_T nexuses.
3004 		 */
3005 		if (preempt_type == PREEMPT_AND_ABORT) {
3006 			core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list,
3007 					   cmd);
3008 			core_scsi3_release_preempt_and_abort(
3009 				&preempt_and_abort_list, pr_reg_n);
3010 		}
3011 
3012 		if (pr_tmpl->pr_aptpl_active)
3013 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3014 
3015 		core_scsi3_put_pr_reg(pr_reg_n);
3016 		core_scsi3_pr_generation(cmd->se_dev);
3017 		return 0;
3018 	}
3019 	/*
3020 	 * The PREEMPTing SA reservation key matches that of the
3021 	 * existing persistent reservation, first, we check if
3022 	 * we are preempting our own reservation.
3023 	 * From spc4r17, section 5.7.11.4.3 Preempting
3024 	 * persistent reservations and registration handling
3025 	 *
3026 	 * If an all registrants persistent reservation is not
3027 	 * present, it is not an error for the persistent
3028 	 * reservation holder to preempt itself (i.e., a
3029 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3030 	 * or a PREEMPT AND ABORT service action with the
3031 	 * SERVICE ACTION RESERVATION KEY value equal to the
3032 	 * persistent reservation holder's reservation key that
3033 	 * is received from the persistent reservation holder).
3034 	 * In that case, the device server shall establish the
3035 	 * new persistent reservation and maintain the
3036 	 * registration.
3037 	 */
3038 	prh_type = pr_res_holder->pr_res_type;
3039 	prh_scope = pr_res_holder->pr_res_scope;
3040 	/*
3041 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3042 	 * persistent reservation holder (see 5.7.10), the device
3043 	 * server shall perform a preempt by doing the following as
3044 	 * an uninterrupted series of actions:
3045 	 *
3046 	 * a) Release the persistent reservation for the holder
3047 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3048 	 */
3049 	if (pr_reg_n != pr_res_holder)
3050 		__core_scsi3_complete_pro_release(dev,
3051 						  pr_res_holder->pr_reg_nacl,
3052 						  dev->dev_pr_res_holder, 0, 0);
3053 	/*
3054 	 * b) Remove the registrations for all I_T nexuses identified
3055 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3056 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3057 	 *    OUT command. If an all registrants persistent reservation
3058 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3059 	 *    is set to zero, then all registrations shall be removed
3060 	 *    except for that of the I_T nexus that is being used for
3061 	 *    the PERSISTENT RESERVE OUT command;
3062 	 */
3063 	spin_lock(&pr_tmpl->registration_lock);
3064 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3065 			&pr_tmpl->registration_list, pr_reg_list) {
3066 
3067 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3068 		if (calling_it_nexus)
3069 			continue;
3070 
3071 		if (sa_res_key && pr_reg->pr_res_key != sa_res_key)
3072 			continue;
3073 
3074 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3075 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3076 		__core_scsi3_free_registration(dev, pr_reg,
3077 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3078 				calling_it_nexus);
3079 		/*
3080 		 * e) Establish a unit attention condition for the initiator
3081 		 *    port associated with every I_T nexus that lost its
3082 		 *    persistent reservation and/or registration, with the
3083 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3084 		 */
3085 		target_ua_allocate_lun(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3086 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3087 	}
3088 	spin_unlock(&pr_tmpl->registration_lock);
3089 	/*
3090 	 * c) Establish a persistent reservation for the preempting
3091 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3092 	 */
3093 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3094 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
3095 			type, scope, preempt_type);
3096 	/*
3097 	 * d) Process tasks as defined in 5.7.1;
3098 	 * e) See above..
3099 	 * f) If the type or scope has changed, then for every I_T nexus
3100 	 *    whose reservation key was not removed, except for the I_T
3101 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3102 	 *    received, the device server shall establish a unit
3103 	 *    attention condition for the initiator port associated with
3104 	 *    that I_T nexus, with the additional sense code set to
3105 	 *    RESERVATIONS RELEASED. If the type or scope have not
3106 	 *    changed, then no unit attention condition(s) shall be
3107 	 *    established for this reason.
3108 	 */
3109 	if ((prh_type != type) || (prh_scope != scope)) {
3110 		spin_lock(&pr_tmpl->registration_lock);
3111 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3112 				&pr_tmpl->registration_list, pr_reg_list) {
3113 
3114 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3115 			if (calling_it_nexus)
3116 				continue;
3117 
3118 			target_ua_allocate_lun(pr_reg->pr_reg_nacl,
3119 					pr_reg->pr_res_mapped_lun, 0x2A,
3120 					ASCQ_2AH_RESERVATIONS_RELEASED);
3121 		}
3122 		spin_unlock(&pr_tmpl->registration_lock);
3123 	}
3124 	spin_unlock(&dev->dev_reservation_lock);
3125 	/*
3126 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3127 	 * All received CDBs for the matching existing reservation and
3128 	 * registrations undergo ABORT_TASK logic.
3129 	 *
3130 	 * From there, core_scsi3_release_preempt_and_abort() will
3131 	 * release every registration in the list (which have already
3132 	 * been removed from the primary pr_reg list), except the
3133 	 * new persistent reservation holder, the calling Initiator Port.
3134 	 */
3135 	if (preempt_type == PREEMPT_AND_ABORT) {
3136 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3137 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3138 						pr_reg_n);
3139 	}
3140 
3141 	if (pr_tmpl->pr_aptpl_active)
3142 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3143 
3144 	core_scsi3_put_pr_reg(pr_reg_n);
3145 	core_scsi3_pr_generation(cmd->se_dev);
3146 	return 0;
3147 }
3148 
3149 static sense_reason_t
3150 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3151 		u64 sa_res_key, int aptpl, int unreg)
3152 {
3153 	struct se_session *se_sess = cmd->se_sess;
3154 	struct se_device *dev = cmd->se_dev;
3155 	struct se_dev_entry *dest_se_deve = NULL;
3156 	struct se_lun *se_lun = cmd->se_lun, *tmp_lun;
3157 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3158 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3159 	const struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3160 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3161 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3162 	unsigned char *buf;
3163 	unsigned char initiator_str[TRANSPORT_IQN_LEN];
3164 	char *iport_ptr = NULL, i_buf[PR_REG_ISID_ID_LEN] = { };
3165 	u32 tid_len, tmp_tid_len;
3166 	int new_reg = 0, type, scope, matching_iname;
3167 	sense_reason_t ret;
3168 	unsigned short rtpi;
3169 	unsigned char proto_ident;
3170 	bool tid_found;
3171 
3172 	if (!se_sess || !se_lun) {
3173 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3174 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3175 	}
3176 
3177 	se_tpg = se_sess->se_tpg;
3178 	tf_ops = se_tpg->se_tpg_tfo;
3179 	/*
3180 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3181 	 *	Register behaviors for a REGISTER AND MOVE service action
3182 	 *
3183 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3184 	 */
3185 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3186 				se_sess);
3187 	if (!pr_reg) {
3188 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3189 			" *pr_reg for REGISTER_AND_MOVE\n");
3190 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3191 	}
3192 	/*
3193 	 * The provided reservation key much match the existing reservation key
3194 	 * provided during this initiator's I_T nexus registration.
3195 	 */
3196 	if (res_key != pr_reg->pr_res_key) {
3197 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3198 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3199 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3200 		ret = TCM_RESERVATION_CONFLICT;
3201 		goto out_put_pr_reg;
3202 	}
3203 	/*
3204 	 * The service active reservation key needs to be non zero
3205 	 */
3206 	if (!sa_res_key) {
3207 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3208 			" sa_res_key\n");
3209 		ret = TCM_INVALID_PARAMETER_LIST;
3210 		goto out_put_pr_reg;
3211 	}
3212 
3213 	/*
3214 	 * Determine the Relative Target Port Identifier where the reservation
3215 	 * will be moved to for the TransportID containing SCSI initiator WWN
3216 	 * information.
3217 	 */
3218 	buf = transport_kmap_data_sg(cmd);
3219 	if (!buf) {
3220 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3221 		goto out_put_pr_reg;
3222 	}
3223 
3224 	rtpi = get_unaligned_be16(&buf[18]);
3225 	tid_len = get_unaligned_be32(&buf[20]);
3226 	transport_kunmap_data_sg(cmd);
3227 	buf = NULL;
3228 
3229 	if ((tid_len + 24) != cmd->data_length) {
3230 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3231 			" does not equal CDB data_length: %u\n", tid_len,
3232 			cmd->data_length);
3233 		ret = TCM_INVALID_PARAMETER_LIST;
3234 		goto out_put_pr_reg;
3235 	}
3236 
3237 	spin_lock(&dev->se_port_lock);
3238 	list_for_each_entry(tmp_lun, &dev->dev_sep_list, lun_dev_link) {
3239 		if (tmp_lun->lun_tpg->tpg_rtpi != rtpi)
3240 			continue;
3241 		dest_se_tpg = tmp_lun->lun_tpg;
3242 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3243 		if (!dest_tf_ops)
3244 			continue;
3245 
3246 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3247 		spin_unlock(&dev->se_port_lock);
3248 
3249 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3250 			pr_err("core_scsi3_tpg_depend_item() failed"
3251 				" for dest_se_tpg\n");
3252 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3253 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3254 			goto out_put_pr_reg;
3255 		}
3256 
3257 		spin_lock(&dev->se_port_lock);
3258 		break;
3259 	}
3260 	spin_unlock(&dev->se_port_lock);
3261 
3262 	if (!dest_se_tpg || !dest_tf_ops) {
3263 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3264 			" fabric ops from Relative Target Port Identifier:"
3265 			" %hu\n", rtpi);
3266 		ret = TCM_INVALID_PARAMETER_LIST;
3267 		goto out_put_pr_reg;
3268 	}
3269 
3270 	buf = transport_kmap_data_sg(cmd);
3271 	if (!buf) {
3272 		ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3273 		goto out_put_pr_reg;
3274 	}
3275 	proto_ident = (buf[24] & 0x0f);
3276 
3277 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3278 			" 0x%02x\n", proto_ident);
3279 
3280 	if (proto_ident != dest_se_tpg->proto_id) {
3281 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3282 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3283 			" from fabric: %s\n", proto_ident,
3284 			dest_se_tpg->proto_id,
3285 			dest_tf_ops->fabric_name);
3286 		ret = TCM_INVALID_PARAMETER_LIST;
3287 		goto out;
3288 	}
3289 	tid_found = target_parse_pr_out_transport_id(dest_se_tpg,
3290 			&buf[24], tid_len, &tmp_tid_len, &iport_ptr, initiator_str);
3291 	if (!tid_found) {
3292 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3293 			" initiator_str from Transport ID\n");
3294 		ret = TCM_INVALID_PARAMETER_LIST;
3295 		goto out;
3296 	}
3297 
3298 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3299 		" %s\n", dest_tf_ops->fabric_name, (iport_ptr != NULL) ?
3300 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3301 		iport_ptr : "");
3302 	/*
3303 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3304 	 * action specifies a TransportID that is the same as the initiator port
3305 	 * of the I_T nexus for the command received, then the command shall
3306 	 * be terminated with CHECK CONDITION status, with the sense key set to
3307 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3308 	 * IN PARAMETER LIST.
3309 	 */
3310 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3311 	matching_iname = (!strcmp(initiator_str,
3312 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3313 	if (!matching_iname)
3314 		goto after_iport_check;
3315 
3316 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3317 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3318 			" matches: %s on received I_T Nexus\n", initiator_str,
3319 			pr_reg_nacl->initiatorname);
3320 		ret = TCM_INVALID_PARAMETER_LIST;
3321 		goto out;
3322 	}
3323 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3324 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3325 			" matches: %s %s on received I_T Nexus\n",
3326 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3327 			pr_reg->pr_reg_isid);
3328 		ret = TCM_INVALID_PARAMETER_LIST;
3329 		goto out;
3330 	}
3331 after_iport_check:
3332 	/*
3333 	 * Locate the destination struct se_node_acl from the received Transport ID
3334 	 */
3335 	mutex_lock(&dest_se_tpg->acl_node_mutex);
3336 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3337 				initiator_str);
3338 	if (dest_node_acl)
3339 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3340 	mutex_unlock(&dest_se_tpg->acl_node_mutex);
3341 
3342 	if (!dest_node_acl) {
3343 		pr_err("Unable to locate %s dest_node_acl for"
3344 			" TransportID%s\n", dest_tf_ops->fabric_name,
3345 			initiator_str);
3346 		ret = TCM_INVALID_PARAMETER_LIST;
3347 		goto out;
3348 	}
3349 
3350 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3351 		pr_err("core_scsi3_nodeacl_depend_item() for"
3352 			" dest_node_acl\n");
3353 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3354 		dest_node_acl = NULL;
3355 		ret = TCM_INVALID_PARAMETER_LIST;
3356 		goto out;
3357 	}
3358 
3359 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3360 		" %s from TransportID\n", dest_tf_ops->fabric_name,
3361 		dest_node_acl->initiatorname);
3362 
3363 	/*
3364 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3365 	 * PORT IDENTIFIER.
3366 	 */
3367 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3368 	if (!dest_se_deve) {
3369 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3370 			" %hu\n",  dest_tf_ops->fabric_name, rtpi);
3371 		ret = TCM_INVALID_PARAMETER_LIST;
3372 		goto out;
3373 	}
3374 
3375 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3376 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3377 		kref_put(&dest_se_deve->pr_kref, target_pr_kref_release);
3378 		dest_se_deve = NULL;
3379 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3380 		goto out;
3381 	}
3382 
3383 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3384 		" ACL for dest_se_deve->mapped_lun: %llu\n",
3385 		dest_tf_ops->fabric_name, dest_node_acl->initiatorname,
3386 		dest_se_deve->mapped_lun);
3387 
3388 	/*
3389 	 * A persistent reservation needs to already existing in order to
3390 	 * successfully complete the REGISTER_AND_MOVE service action..
3391 	 */
3392 	spin_lock(&dev->dev_reservation_lock);
3393 	pr_res_holder = dev->dev_pr_res_holder;
3394 	if (!pr_res_holder) {
3395 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3396 			" currently held\n");
3397 		spin_unlock(&dev->dev_reservation_lock);
3398 		ret = TCM_INVALID_CDB_FIELD;
3399 		goto out;
3400 	}
3401 	/*
3402 	 * The received on I_T Nexus must be the reservation holder.
3403 	 *
3404 	 * From spc4r17 section 5.7.8  Table 50 --
3405 	 * 	Register behaviors for a REGISTER AND MOVE service action
3406 	 */
3407 	if (!is_reservation_holder(pr_res_holder, pr_reg)) {
3408 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3409 			" Nexus is not reservation holder\n");
3410 		spin_unlock(&dev->dev_reservation_lock);
3411 		ret = TCM_RESERVATION_CONFLICT;
3412 		goto out;
3413 	}
3414 	/*
3415 	 * From spc4r17 section 5.7.8: registering and moving reservation
3416 	 *
3417 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3418 	 * action is received and the established persistent reservation is a
3419 	 * Write Exclusive - All Registrants type or Exclusive Access -
3420 	 * All Registrants type reservation, then the command shall be completed
3421 	 * with RESERVATION CONFLICT status.
3422 	 */
3423 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3424 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3425 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3426 			" reservation for type: %s\n",
3427 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3428 		spin_unlock(&dev->dev_reservation_lock);
3429 		ret = TCM_RESERVATION_CONFLICT;
3430 		goto out;
3431 	}
3432 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3433 	/*
3434 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3435 	 */
3436 	type = pr_res_holder->pr_res_type;
3437 	scope = pr_res_holder->pr_res_type;
3438 	/*
3439 	 * c) Associate the reservation key specified in the SERVICE ACTION
3440 	 *    RESERVATION KEY field with the I_T nexus specified as the
3441 	 *    destination of the register and move, where:
3442 	 *    A) The I_T nexus is specified by the TransportID and the
3443 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3444 	 *    B) Regardless of the TransportID format used, the association for
3445 	 *       the initiator port is based on either the initiator port name
3446 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3447 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3448 	 *       transport protocols where port names are not required;
3449 	 * d) Register the reservation key specified in the SERVICE ACTION
3450 	 *    RESERVATION KEY field;
3451 	 *
3452 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3453 	 * register an I_T nexus that is already registered with the same
3454 	 * reservation key or a different reservation key.
3455 	 */
3456 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3457 					iport_ptr);
3458 	if (!dest_pr_reg) {
3459 		struct se_lun *dest_lun = dest_se_deve->se_lun;
3460 
3461 		spin_unlock(&dev->dev_reservation_lock);
3462 		if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
3463 					dest_lun, dest_se_deve, dest_se_deve->mapped_lun,
3464 					iport_ptr, sa_res_key, 0, aptpl, 2, 1)) {
3465 			ret = TCM_INSUFFICIENT_REGISTRATION_RESOURCES;
3466 			goto out;
3467 		}
3468 		spin_lock(&dev->dev_reservation_lock);
3469 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3470 						iport_ptr);
3471 		new_reg = 1;
3472 	} else {
3473 		/*
3474 		 * e) Retain the reservation key specified in the SERVICE ACTION
3475 		 *    RESERVATION KEY field and associated information;
3476 		 */
3477 		dest_pr_reg->pr_res_key = sa_res_key;
3478 	}
3479 	/*
3480 	 * f) Release the persistent reservation for the persistent reservation
3481 	 *    holder (i.e., the I_T nexus on which the
3482 	 */
3483 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3484 					  dev->dev_pr_res_holder, 0, 0);
3485 	/*
3486 	 * g) Move the persistent reservation to the specified I_T nexus using
3487 	 *    the same scope and type as the persistent reservation released in
3488 	 *    item f); and
3489 	 */
3490 	dev->dev_pr_res_holder = dest_pr_reg;
3491 	dest_pr_reg->pr_res_holder = 1;
3492 	dest_pr_reg->pr_res_type = type;
3493 	pr_reg->pr_res_scope = scope;
3494 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3495 	/*
3496 	 * Increment PRGeneration for existing registrations..
3497 	 */
3498 	if (!new_reg)
3499 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3500 	spin_unlock(&dev->dev_reservation_lock);
3501 
3502 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3503 		" created new reservation holder TYPE: %s on object RTPI:"
3504 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->fabric_name,
3505 		core_scsi3_pr_dump_type(type), rtpi,
3506 		dest_pr_reg->pr_res_generation);
3507 	pr_debug("SPC-3 PR Successfully moved reservation from"
3508 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3509 		tf_ops->fabric_name, pr_reg_nacl->initiatorname,
3510 		i_buf, dest_tf_ops->fabric_name,
3511 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3512 		iport_ptr : "");
3513 	/*
3514 	 * It is now safe to release configfs group dependencies for destination
3515 	 * of Transport ID Initiator Device/Port Identifier
3516 	 */
3517 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3518 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3519 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3520 	/*
3521 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3522 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3523 	 */
3524 	if (unreg) {
3525 		spin_lock(&pr_tmpl->registration_lock);
3526 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3527 		spin_unlock(&pr_tmpl->registration_lock);
3528 	} else
3529 		core_scsi3_put_pr_reg(pr_reg);
3530 
3531 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3532 
3533 	core_scsi3_put_pr_reg(dest_pr_reg);
3534 	/*
3535 	 * iport_ptr aliases the PR-OUT parameter list mapped above, so the
3536 	 * buffer is unmapped only here on success (and at out: on error).
3537 	 */
3538 	transport_kunmap_data_sg(cmd);
3539 	return 0;
3540 out:
3541 	if (buf)
3542 		transport_kunmap_data_sg(cmd);
3543 	if (dest_se_deve)
3544 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3545 	if (dest_node_acl)
3546 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3547 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3548 
3549 out_put_pr_reg:
3550 	core_scsi3_put_pr_reg(pr_reg);
3551 	return ret;
3552 }
3553 
3554 static sense_reason_t
3555 target_try_pr_out_pt(struct se_cmd *cmd, u8 sa, u64 res_key, u64 sa_res_key,
3556 		     u8 type, bool aptpl, bool all_tg_pt, bool spec_i_pt)
3557 {
3558 	struct exec_cmd_ops *ops = cmd->protocol_data;
3559 
3560 	if (!cmd->se_sess || !cmd->se_lun) {
3561 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3562 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3563 	}
3564 
3565 	if (!ops->execute_pr_out) {
3566 		pr_err("SPC-3 PR: Device has been configured for PR passthrough but it's not supported by the backend.\n");
3567 		return TCM_UNSUPPORTED_SCSI_OPCODE;
3568 	}
3569 
3570 	switch (sa) {
3571 	case PRO_REGISTER_AND_MOVE:
3572 	case PRO_REPLACE_LOST_RESERVATION:
3573 		pr_err("SPC-3 PR: PRO_REGISTER_AND_MOVE and PRO_REPLACE_LOST_RESERVATION are not supported by PR passthrough.\n");
3574 		return TCM_UNSUPPORTED_SCSI_OPCODE;
3575 	}
3576 
3577 	if (spec_i_pt || all_tg_pt) {
3578 		pr_err("SPC-3 PR: SPEC_I_PT and ALL_TG_PT are not supported by PR passthrough.\n");
3579 		return TCM_UNSUPPORTED_SCSI_OPCODE;
3580 	}
3581 
3582 	return ops->execute_pr_out(cmd, sa, res_key, sa_res_key, type, aptpl);
3583 }
3584 
3585 /*
3586  * See spc4r17 section 6.14 Table 170
3587  */
3588 sense_reason_t
3589 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3590 {
3591 	struct se_device *dev = cmd->se_dev;
3592 	unsigned char *cdb = &cmd->t_task_cdb[0];
3593 	unsigned char *buf;
3594 	u64 res_key, sa_res_key;
3595 	int sa, scope, type, aptpl;
3596 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3597 	sense_reason_t ret;
3598 
3599 	/*
3600 	 * Following spc2r20 5.5.1 Reservations overview:
3601 	 *
3602 	 * If a logical unit has been reserved by any RESERVE command and is
3603 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3604 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3605 	 * initiator or service action and shall terminate with a RESERVATION
3606 	 * CONFLICT status.
3607 	 */
3608 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3609 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3610 			" SPC-2 reservation is held, returning"
3611 			" RESERVATION_CONFLICT\n");
3612 		return TCM_RESERVATION_CONFLICT;
3613 	}
3614 
3615 	/*
3616 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3617 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3618 	 */
3619 	if (!cmd->se_sess)
3620 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3621 
3622 	if (cmd->data_length < 24) {
3623 		pr_warn("SPC-PR: Received PR OUT parameter list"
3624 			" length too small: %u\n", cmd->data_length);
3625 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3626 	}
3627 
3628 	/*
3629 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3630 	 */
3631 	sa = (cdb[1] & 0x1f);
3632 	scope = (cdb[2] & 0xf0);
3633 	type = (cdb[2] & 0x0f);
3634 
3635 	buf = transport_kmap_data_sg(cmd);
3636 	if (!buf)
3637 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3638 
3639 	/*
3640 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3641 	 */
3642 	res_key = get_unaligned_be64(&buf[0]);
3643 	sa_res_key = get_unaligned_be64(&buf[8]);
3644 	/*
3645 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3646 	 * SCSI TransportIDs.
3647 	 */
3648 	if (sa != PRO_REGISTER_AND_MOVE) {
3649 		spec_i_pt = (buf[20] & 0x08);
3650 		all_tg_pt = (buf[20] & 0x04);
3651 		aptpl = (buf[20] & 0x01);
3652 	} else {
3653 		aptpl = (buf[17] & 0x01);
3654 		unreg = (buf[17] & 0x02);
3655 	}
3656 	/*
3657 	 * If the backend device has been configured to force APTPL metadata
3658 	 * write-out, go ahead and propigate aptpl=1 down now.
3659 	 */
3660 	if (dev->dev_attrib.force_pr_aptpl)
3661 		aptpl = 1;
3662 
3663 	transport_kunmap_data_sg(cmd);
3664 	buf = NULL;
3665 
3666 	/*
3667 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3668 	 */
3669 	if (spec_i_pt && (sa != PRO_REGISTER))
3670 		return TCM_INVALID_PARAMETER_LIST;
3671 
3672 	/*
3673 	 * From spc4r17 section 6.14:
3674 	 *
3675 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3676 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3677 	 * the command shall be terminated with CHECK CONDITION status, with
3678 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3679 	 * code set to PARAMETER LIST LENGTH ERROR.
3680 	 */
3681 	if (!spec_i_pt && (sa != PRO_REGISTER_AND_MOVE) &&
3682 	    (cmd->data_length != 24)) {
3683 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3684 			" list length: %u\n", cmd->data_length);
3685 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
3686 	}
3687 
3688 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) {
3689 		ret = target_try_pr_out_pt(cmd, sa, res_key, sa_res_key, type,
3690 					   aptpl, all_tg_pt, spec_i_pt);
3691 		goto done;
3692 	}
3693 
3694 	/*
3695 	 * (core_scsi3_emulate_pro_* function parameters
3696 	 * are defined by spc4r17 Table 174:
3697 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3698 	 */
3699 	switch (sa) {
3700 	case PRO_REGISTER:
3701 		ret = core_scsi3_emulate_pro_register(cmd,
3702 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3703 		break;
3704 	case PRO_RESERVE:
3705 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3706 		break;
3707 	case PRO_RELEASE:
3708 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3709 		break;
3710 	case PRO_CLEAR:
3711 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3712 		break;
3713 	case PRO_PREEMPT:
3714 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3715 					res_key, sa_res_key, PREEMPT);
3716 		break;
3717 	case PRO_PREEMPT_AND_ABORT:
3718 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3719 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3720 		break;
3721 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3722 		ret = core_scsi3_emulate_pro_register(cmd,
3723 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3724 		break;
3725 	case PRO_REGISTER_AND_MOVE:
3726 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3727 				sa_res_key, aptpl, unreg);
3728 		break;
3729 	default:
3730 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3731 			" action: 0x%02x\n", sa);
3732 		return TCM_INVALID_CDB_FIELD;
3733 	}
3734 
3735 done:
3736 	if (!ret)
3737 		target_complete_cmd(cmd, SAM_STAT_GOOD);
3738 	return ret;
3739 }
3740 
3741 /*
3742  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3743  *
3744  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3745  */
3746 static sense_reason_t
3747 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3748 {
3749 	struct se_device *dev = cmd->se_dev;
3750 	struct t10_pr_registration *pr_reg;
3751 	unsigned char *buf;
3752 	u32 add_len = 0, off = 8;
3753 
3754 	if (cmd->data_length < 8) {
3755 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3756 			" too small\n", cmd->data_length);
3757 		return TCM_INVALID_CDB_FIELD;
3758 	}
3759 
3760 	buf = transport_kmap_data_sg(cmd);
3761 	if (!buf)
3762 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3763 
3764 	put_unaligned_be32(dev->t10_pr.pr_generation, buf);
3765 
3766 	spin_lock(&dev->t10_pr.registration_lock);
3767 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3768 			pr_reg_list) {
3769 		/*
3770 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3771 		 * next reservation key list descriptor.
3772 		 */
3773 		if (off + 8 <= cmd->data_length) {
3774 			put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
3775 			off += 8;
3776 		}
3777 		/*
3778 		 * SPC5r17: 6.16.2 READ KEYS service action
3779 		 * The ADDITIONAL LENGTH field indicates the number of bytes in
3780 		 * the Reservation key list. The contents of the ADDITIONAL
3781 		 * LENGTH field are not altered based on the allocation length
3782 		 */
3783 		add_len += 8;
3784 	}
3785 	spin_unlock(&dev->t10_pr.registration_lock);
3786 
3787 	put_unaligned_be32(add_len, &buf[4]);
3788 	target_set_cmd_data_length(cmd, 8 + add_len);
3789 
3790 	transport_kunmap_data_sg(cmd);
3791 
3792 	return 0;
3793 }
3794 
3795 /*
3796  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3797  *
3798  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3799  */
3800 static sense_reason_t
3801 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3802 {
3803 	struct se_device *dev = cmd->se_dev;
3804 	struct t10_pr_registration *pr_reg;
3805 	unsigned char *buf;
3806 	u64 pr_res_key;
3807 	u32 add_len = 0;
3808 
3809 	if (cmd->data_length < 8) {
3810 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3811 			" too small\n", cmd->data_length);
3812 		return TCM_INVALID_CDB_FIELD;
3813 	}
3814 
3815 	buf = transport_kmap_data_sg(cmd);
3816 	if (!buf)
3817 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3818 
3819 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3820 
3821 	spin_lock(&dev->dev_reservation_lock);
3822 	pr_reg = dev->dev_pr_res_holder;
3823 	if (pr_reg) {
3824 		/*
3825 		 * Set the Additional Length to 16 when a reservation is held
3826 		 */
3827 		add_len = 16;
3828 		put_unaligned_be32(add_len, &buf[4]);
3829 
3830 		if (cmd->data_length < 22)
3831 			goto err;
3832 
3833 		/*
3834 		 * Set the Reservation key.
3835 		 *
3836 		 * From spc4r17, section 5.7.10:
3837 		 * A persistent reservation holder has its reservation key
3838 		 * returned in the parameter data from a PERSISTENT
3839 		 * RESERVE IN command with READ RESERVATION service action as
3840 		 * follows:
3841 		 * a) For a persistent reservation of the type Write Exclusive
3842 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3843 		 *      the reservation key shall be set to zero; or
3844 		 * b) For all other persistent reservation types, the
3845 		 *    reservation key shall be set to the registered
3846 		 *    reservation key for the I_T nexus that holds the
3847 		 *    persistent reservation.
3848 		 */
3849 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3850 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3851 			pr_res_key = 0;
3852 		else
3853 			pr_res_key = pr_reg->pr_res_key;
3854 
3855 		put_unaligned_be64(pr_res_key, &buf[8]);
3856 		/*
3857 		 * Set the SCOPE and TYPE
3858 		 */
3859 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3860 			  (pr_reg->pr_res_type & 0x0f);
3861 	}
3862 
3863 	target_set_cmd_data_length(cmd, 8 + add_len);
3864 
3865 err:
3866 	spin_unlock(&dev->dev_reservation_lock);
3867 	transport_kunmap_data_sg(cmd);
3868 
3869 	return 0;
3870 }
3871 
3872 /*
3873  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3874  *
3875  * See spc4r17 section 6.13.4 Table 165
3876  */
3877 static sense_reason_t
3878 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3879 {
3880 	struct se_device *dev = cmd->se_dev;
3881 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3882 	unsigned char *buf;
3883 	u16 len = 8; /* Hardcoded to 8. */
3884 
3885 	if (cmd->data_length < 6) {
3886 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3887 			" %u too small\n", cmd->data_length);
3888 		return TCM_INVALID_CDB_FIELD;
3889 	}
3890 
3891 	buf = transport_kmap_data_sg(cmd);
3892 	if (!buf)
3893 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3894 
3895 	put_unaligned_be16(len, &buf[0]);
3896 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3897 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3898 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3899 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3900 	/*
3901 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3902 	 * set the TMV: Task Mask Valid bit.
3903 	 */
3904 	buf[3] |= 0x80;
3905 	/*
3906 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3907 	 */
3908 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3909 	/*
3910 	 * PTPL_A: Persistence across Target Power Loss Active bit
3911 	 */
3912 	if (pr_tmpl->pr_aptpl_active)
3913 		buf[3] |= 0x01;
3914 	/*
3915 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3916 	 */
3917 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3918 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3919 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3920 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3921 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3922 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3923 
3924 	target_set_cmd_data_length(cmd, len);
3925 
3926 	transport_kunmap_data_sg(cmd);
3927 
3928 	return 0;
3929 }
3930 
3931 /*
3932  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3933  *
3934  * See spc4r17 section 6.13.5 Table 168 and 169
3935  */
3936 static sense_reason_t
3937 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3938 {
3939 	struct se_device *dev = cmd->se_dev;
3940 	struct se_node_acl *se_nacl;
3941 	struct se_portal_group *se_tpg;
3942 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3943 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3944 	unsigned char *buf;
3945 	u32 add_desc_len = 0, add_len = 0;
3946 	u32 off = 8; /* off into first Full Status descriptor */
3947 	int format_code = 0, pr_res_type = 0, pr_res_scope = 0;
3948 	int exp_desc_len, desc_len;
3949 	bool all_reg = false;
3950 
3951 	if (cmd->data_length < 8) {
3952 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3953 			" too small\n", cmd->data_length);
3954 		return TCM_INVALID_CDB_FIELD;
3955 	}
3956 
3957 	buf = transport_kmap_data_sg(cmd);
3958 	if (!buf)
3959 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3960 
3961 	put_unaligned_be32(dev->t10_pr.pr_generation, &buf[0]);
3962 
3963 	spin_lock(&dev->dev_reservation_lock);
3964 	if (dev->dev_pr_res_holder) {
3965 		struct t10_pr_registration *pr_holder = dev->dev_pr_res_holder;
3966 
3967 		if (pr_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG ||
3968 		    pr_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG) {
3969 			all_reg = true;
3970 			pr_res_type = pr_holder->pr_res_type;
3971 			pr_res_scope = pr_holder->pr_res_scope;
3972 		}
3973 	}
3974 	spin_unlock(&dev->dev_reservation_lock);
3975 
3976 	spin_lock(&pr_tmpl->registration_lock);
3977 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3978 			&pr_tmpl->registration_list, pr_reg_list) {
3979 
3980 		se_nacl = pr_reg->pr_reg_nacl;
3981 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3982 		add_desc_len = 0;
3983 
3984 		atomic_inc_mb(&pr_reg->pr_res_holders);
3985 		spin_unlock(&pr_tmpl->registration_lock);
3986 		/*
3987 		 * Determine expected length of $FABRIC_MOD specific
3988 		 * TransportID full status descriptor..
3989 		 */
3990 		exp_desc_len = target_get_pr_transport_id_len(se_nacl, pr_reg,
3991 					&format_code);
3992 		if (exp_desc_len < 0 ||
3993 		    exp_desc_len + add_len > cmd->data_length) {
3994 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3995 				" out of buffer: %d\n", cmd->data_length);
3996 			spin_lock(&pr_tmpl->registration_lock);
3997 			atomic_dec_mb(&pr_reg->pr_res_holders);
3998 			break;
3999 		}
4000 		/*
4001 		 * Set RESERVATION KEY
4002 		 */
4003 		put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
4004 		off += 8;
4005 		off += 4; /* Skip Over Reserved area */
4006 
4007 		/*
4008 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
4009 		 */
4010 		if (pr_reg->pr_reg_all_tg_pt)
4011 			buf[off] = 0x02;
4012 		/*
4013 		 * The struct se_lun pointer will be present for the
4014 		 * reservation holder for PR_HOLDER bit.
4015 		 *
4016 		 * Also, if this registration is the reservation
4017 		 * holder or there is an All Registrants reservation
4018 		 * active, fill in SCOPE and TYPE in the next byte.
4019 		 */
4020 		if (pr_reg->pr_res_holder) {
4021 			buf[off++] |= 0x01;
4022 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
4023 				     (pr_reg->pr_res_type & 0x0f);
4024 		} else if (all_reg) {
4025 			buf[off++] |= 0x01;
4026 			buf[off++] = (pr_res_scope & 0xf0) |
4027 				     (pr_res_type & 0x0f);
4028 		} else {
4029 			off += 2;
4030 		}
4031 
4032 		off += 4; /* Skip over reserved area */
4033 		/*
4034 		 * From spc4r17 6.3.15:
4035 		 *
4036 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4037 		 * IDENTIFIER field contains the relative port identifier (see
4038 		 * 3.1.120) of the target port that is part of the I_T nexus
4039 		 * described by this full status descriptor. If the ALL_TG_PT
4040 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4041 		 * IDENTIFIER field are not defined by this standard.
4042 		 */
4043 		if (!pr_reg->pr_reg_all_tg_pt) {
4044 			u16 sep_rtpi = pr_reg->tg_pt_sep_rtpi;
4045 
4046 			put_unaligned_be16(sep_rtpi, &buf[off]);
4047 			off += 2;
4048 		} else
4049 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
4050 
4051 		buf[off+4] = se_tpg->proto_id;
4052 
4053 		/*
4054 		 * Now, have the $FABRIC_MOD fill in the transport ID.
4055 		 */
4056 		desc_len = target_get_pr_transport_id(se_nacl, pr_reg,
4057 				&format_code, &buf[off+4]);
4058 
4059 		spin_lock(&pr_tmpl->registration_lock);
4060 		atomic_dec_mb(&pr_reg->pr_res_holders);
4061 
4062 		if (desc_len < 0)
4063 			break;
4064 		/*
4065 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4066 		 */
4067 		put_unaligned_be32(desc_len, &buf[off]);
4068 		off += 4;
4069 		/*
4070 		 * Size of full desctipor header minus TransportID
4071 		 * containing $FABRIC_MOD specific) initiator device/port
4072 		 * WWN information.
4073 		 *
4074 		 *  See spc4r17 Section 6.13.5 Table 169
4075 		 */
4076 		add_desc_len = (24 + desc_len);
4077 
4078 		off += desc_len;
4079 		add_len += add_desc_len;
4080 	}
4081 	spin_unlock(&pr_tmpl->registration_lock);
4082 	/*
4083 	 * Set ADDITIONAL_LENGTH
4084 	 */
4085 	put_unaligned_be32(add_len, &buf[4]);
4086 	target_set_cmd_data_length(cmd, 8 + add_len);
4087 
4088 	transport_kunmap_data_sg(cmd);
4089 
4090 	return 0;
4091 }
4092 
4093 static sense_reason_t target_try_pr_in_pt(struct se_cmd *cmd, u8 sa)
4094 {
4095 	struct exec_cmd_ops *ops = cmd->protocol_data;
4096 	unsigned char *buf;
4097 	sense_reason_t ret;
4098 
4099 	if (cmd->data_length < 8) {
4100 		pr_err("PRIN SA SCSI Data Length: %u too small\n",
4101 		       cmd->data_length);
4102 		return TCM_INVALID_CDB_FIELD;
4103 	}
4104 
4105 	if (!ops->execute_pr_in) {
4106 		pr_err("SPC-3 PR: Device has been configured for PR passthrough but it's not supported by the backend.\n");
4107 		return TCM_UNSUPPORTED_SCSI_OPCODE;
4108 	}
4109 
4110 	if (sa == PRI_READ_FULL_STATUS) {
4111 		pr_err("SPC-3 PR: PRI_READ_FULL_STATUS is not supported by PR passthrough.\n");
4112 		return TCM_UNSUPPORTED_SCSI_OPCODE;
4113 	}
4114 
4115 	buf = transport_kmap_data_sg(cmd);
4116 	if (!buf)
4117 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
4118 
4119 	ret = ops->execute_pr_in(cmd, sa, buf);
4120 
4121 	transport_kunmap_data_sg(cmd);
4122 	return ret;
4123 }
4124 
4125 sense_reason_t
4126 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4127 {
4128 	u8 sa = cmd->t_task_cdb[1] & 0x1f;
4129 	sense_reason_t ret;
4130 
4131 	/*
4132 	 * Following spc2r20 5.5.1 Reservations overview:
4133 	 *
4134 	 * If a logical unit has been reserved by any RESERVE command and is
4135 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4136 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4137 	 * initiator or service action and shall terminate with a RESERVATION
4138 	 * CONFLICT status.
4139 	 */
4140 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4141 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4142 			" SPC-2 reservation is held, returning"
4143 			" RESERVATION_CONFLICT\n");
4144 		return TCM_RESERVATION_CONFLICT;
4145 	}
4146 
4147 	if (cmd->se_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR) {
4148 		ret = target_try_pr_in_pt(cmd, sa);
4149 		goto done;
4150 	}
4151 
4152 	switch (sa) {
4153 	case PRI_READ_KEYS:
4154 		ret = core_scsi3_pri_read_keys(cmd);
4155 		break;
4156 	case PRI_READ_RESERVATION:
4157 		ret = core_scsi3_pri_read_reservation(cmd);
4158 		break;
4159 	case PRI_REPORT_CAPABILITIES:
4160 		ret = core_scsi3_pri_report_capabilities(cmd);
4161 		break;
4162 	case PRI_READ_FULL_STATUS:
4163 		ret = core_scsi3_pri_read_full_status(cmd);
4164 		break;
4165 	default:
4166 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4167 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4168 		return TCM_INVALID_CDB_FIELD;
4169 	}
4170 
4171 done:
4172 	if (!ret)
4173 		target_complete_cmd(cmd, SAM_STAT_GOOD);
4174 	return ret;
4175 }
4176 
4177 sense_reason_t
4178 target_check_reservation(struct se_cmd *cmd)
4179 {
4180 	struct se_device *dev = cmd->se_dev;
4181 	sense_reason_t ret;
4182 
4183 	if (!cmd->se_sess)
4184 		return 0;
4185 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4186 		return 0;
4187 	if (!dev->dev_attrib.emulate_pr)
4188 		return 0;
4189 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_PGR)
4190 		return 0;
4191 
4192 	spin_lock(&dev->dev_reservation_lock);
4193 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4194 		ret = target_scsi2_reservation_check(cmd);
4195 	else
4196 		ret = target_scsi3_pr_reservation_check(cmd);
4197 	spin_unlock(&dev->dev_reservation_lock);
4198 
4199 	return ret;
4200 }
4201