1 /*******************************************************************************
2  * Filename:  target_core_pr.c
3  *
4  * This file contains SPC-3 compliant persistent reservations and
5  * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
6  *
7  * (c) Copyright 2009-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24  *
25  ******************************************************************************/
26 
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/list.h>
30 #include <linux/file.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_cmnd.h>
33 #include <asm/unaligned.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_backend.h>
37 #include <target/target_core_fabric.h>
38 #include <target/target_core_configfs.h>
39 
40 #include "target_core_internal.h"
41 #include "target_core_pr.h"
42 #include "target_core_ua.h"
43 
44 /*
45  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
46  */
47 struct pr_transport_id_holder {
48 	int dest_local_nexus;
49 	struct t10_pr_registration *dest_pr_reg;
50 	struct se_portal_group *dest_tpg;
51 	struct se_node_acl *dest_node_acl;
52 	struct se_dev_entry *dest_se_deve;
53 	struct list_head dest_list;
54 };
55 
56 void core_pr_dump_initiator_port(
57 	struct t10_pr_registration *pr_reg,
58 	char *buf,
59 	u32 size)
60 {
61 	if (!pr_reg->isid_present_at_reg)
62 		buf[0] = '\0';
63 
64 	snprintf(buf, size, ",i,0x%s", pr_reg->pr_reg_isid);
65 }
66 
67 enum register_type {
68 	REGISTER,
69 	REGISTER_AND_IGNORE_EXISTING_KEY,
70 	REGISTER_AND_MOVE,
71 };
72 
73 enum preempt_type {
74 	PREEMPT,
75 	PREEMPT_AND_ABORT,
76 };
77 
78 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
79 			struct t10_pr_registration *, int);
80 
81 static sense_reason_t
82 target_scsi2_reservation_check(struct se_cmd *cmd)
83 {
84 	struct se_device *dev = cmd->se_dev;
85 	struct se_session *sess = cmd->se_sess;
86 
87 	switch (cmd->t_task_cdb[0]) {
88 	case INQUIRY:
89 	case RELEASE:
90 	case RELEASE_10:
91 		return 0;
92 	default:
93 		break;
94 	}
95 
96 	if (!dev->dev_reserved_node_acl || !sess)
97 		return 0;
98 
99 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
100 		return TCM_RESERVATION_CONFLICT;
101 
102 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
103 		if (dev->dev_res_bin_isid != sess->sess_bin_isid)
104 			return TCM_RESERVATION_CONFLICT;
105 	}
106 
107 	return 0;
108 }
109 
110 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
111 					struct se_node_acl *, struct se_session *);
112 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
113 
114 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
115 {
116 	struct se_session *se_sess = cmd->se_sess;
117 	struct se_device *dev = cmd->se_dev;
118 	struct t10_pr_registration *pr_reg;
119 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
120 	int conflict = 0;
121 
122 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
123 			se_sess);
124 	if (pr_reg) {
125 		/*
126 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
127 		 * behavior
128 		 *
129 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
130 		 * status, but no reservation shall be established and the
131 		 * persistent reservation shall not be changed, if the command
132 		 * is received from a) and b) below.
133 		 *
134 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
135 		 * status, but the persistent reservation shall not be released,
136 		 * if the command is received from a) and b)
137 		 *
138 		 * a) An I_T nexus that is a persistent reservation holder; or
139 		 * b) An I_T nexus that is registered if a registrants only or
140 		 *    all registrants type persistent reservation is present.
141 		 *
142 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
143 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
144 		 * as defined in SPC-2.
145 		 */
146 		if (pr_reg->pr_res_holder) {
147 			core_scsi3_put_pr_reg(pr_reg);
148 			return 1;
149 		}
150 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
151 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
152 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
153 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
154 			core_scsi3_put_pr_reg(pr_reg);
155 			return 1;
156 		}
157 		core_scsi3_put_pr_reg(pr_reg);
158 		conflict = 1;
159 	} else {
160 		/*
161 		 * Following spc2r20 5.5.1 Reservations overview:
162 		 *
163 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
164 		 * command with the REGISTER or the REGISTER AND IGNORE
165 		 * EXISTING KEY service action and is still registered by any
166 		 * initiator, all RESERVE commands and all RELEASE commands
167 		 * regardless of initiator shall conflict and shall terminate
168 		 * with a RESERVATION CONFLICT status.
169 		 */
170 		spin_lock(&pr_tmpl->registration_lock);
171 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
172 		spin_unlock(&pr_tmpl->registration_lock);
173 	}
174 
175 	if (conflict) {
176 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
177 			" while active SPC-3 registrations exist,"
178 			" returning RESERVATION_CONFLICT\n");
179 		return -EBUSY;
180 	}
181 
182 	return 0;
183 }
184 
185 sense_reason_t
186 target_scsi2_reservation_release(struct se_cmd *cmd)
187 {
188 	struct se_device *dev = cmd->se_dev;
189 	struct se_session *sess = cmd->se_sess;
190 	struct se_portal_group *tpg;
191 	int rc;
192 
193 	if (!sess || !sess->se_tpg)
194 		goto out;
195 	rc = target_check_scsi2_reservation_conflict(cmd);
196 	if (rc == 1)
197 		goto out;
198 	if (rc < 0)
199 		return TCM_RESERVATION_CONFLICT;
200 
201 	spin_lock(&dev->dev_reservation_lock);
202 	if (!dev->dev_reserved_node_acl || !sess)
203 		goto out_unlock;
204 
205 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
206 		goto out_unlock;
207 
208 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
209 		goto out_unlock;
210 
211 	dev->dev_reserved_node_acl = NULL;
212 	dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
213 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
214 		dev->dev_res_bin_isid = 0;
215 		dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS_WITH_ISID;
216 	}
217 	tpg = sess->se_tpg;
218 	pr_debug("SCSI-2 Released reservation for %s LUN: %u ->"
219 		" MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
220 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
221 		sess->se_node_acl->initiatorname);
222 
223 out_unlock:
224 	spin_unlock(&dev->dev_reservation_lock);
225 out:
226 	target_complete_cmd(cmd, GOOD);
227 	return 0;
228 }
229 
230 sense_reason_t
231 target_scsi2_reservation_reserve(struct se_cmd *cmd)
232 {
233 	struct se_device *dev = cmd->se_dev;
234 	struct se_session *sess = cmd->se_sess;
235 	struct se_portal_group *tpg;
236 	sense_reason_t ret = 0;
237 	int rc;
238 
239 	if ((cmd->t_task_cdb[1] & 0x01) &&
240 	    (cmd->t_task_cdb[1] & 0x02)) {
241 		pr_err("LongIO and Obselete Bits set, returning"
242 				" ILLEGAL_REQUEST\n");
243 		return TCM_UNSUPPORTED_SCSI_OPCODE;
244 	}
245 	/*
246 	 * This is currently the case for target_core_mod passthrough struct se_cmd
247 	 * ops
248 	 */
249 	if (!sess || !sess->se_tpg)
250 		goto out;
251 	rc = target_check_scsi2_reservation_conflict(cmd);
252 	if (rc == 1)
253 		goto out;
254 
255 	if (rc < 0)
256 		return TCM_RESERVATION_CONFLICT;
257 
258 	tpg = sess->se_tpg;
259 	spin_lock(&dev->dev_reservation_lock);
260 	if (dev->dev_reserved_node_acl &&
261 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
262 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
263 			tpg->se_tpg_tfo->get_fabric_name());
264 		pr_err("Original reserver LUN: %u %s\n",
265 			cmd->se_lun->unpacked_lun,
266 			dev->dev_reserved_node_acl->initiatorname);
267 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
268 			" from %s \n", cmd->se_lun->unpacked_lun,
269 			cmd->se_deve->mapped_lun,
270 			sess->se_node_acl->initiatorname);
271 		ret = TCM_RESERVATION_CONFLICT;
272 		goto out_unlock;
273 	}
274 
275 	dev->dev_reserved_node_acl = sess->se_node_acl;
276 	dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS;
277 	if (sess->sess_bin_isid != 0) {
278 		dev->dev_res_bin_isid = sess->sess_bin_isid;
279 		dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS_WITH_ISID;
280 	}
281 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
282 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
283 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
284 		sess->se_node_acl->initiatorname);
285 
286 out_unlock:
287 	spin_unlock(&dev->dev_reservation_lock);
288 out:
289 	if (!ret)
290 		target_complete_cmd(cmd, GOOD);
291 	return ret;
292 }
293 
294 
295 /*
296  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
297  *
298  * This function is called by those initiator ports who are *NOT*
299  * the active PR reservation holder when a reservation is present.
300  */
301 static int core_scsi3_pr_seq_non_holder(
302 	struct se_cmd *cmd,
303 	u32 pr_reg_type)
304 {
305 	unsigned char *cdb = cmd->t_task_cdb;
306 	struct se_dev_entry *se_deve;
307 	struct se_session *se_sess = cmd->se_sess;
308 	int other_cdb = 0, ignore_reg;
309 	int registered_nexus = 0, ret = 1; /* Conflict by default */
310 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
311 	int we = 0; /* Write Exclusive */
312 	int legacy = 0; /* Act like a legacy device and return
313 			 * RESERVATION CONFLICT on some CDBs */
314 
315 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
316 	/*
317 	 * Determine if the registration should be ignored due to
318 	 * non-matching ISIDs in target_scsi3_pr_reservation_check().
319 	 */
320 	ignore_reg = (pr_reg_type & 0x80000000);
321 	if (ignore_reg)
322 		pr_reg_type &= ~0x80000000;
323 
324 	switch (pr_reg_type) {
325 	case PR_TYPE_WRITE_EXCLUSIVE:
326 		we = 1;
327 	case PR_TYPE_EXCLUSIVE_ACCESS:
328 		/*
329 		 * Some commands are only allowed for the persistent reservation
330 		 * holder.
331 		 */
332 		if ((se_deve->def_pr_registered) && !(ignore_reg))
333 			registered_nexus = 1;
334 		break;
335 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
336 		we = 1;
337 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
338 		/*
339 		 * Some commands are only allowed for registered I_T Nexuses.
340 		 */
341 		reg_only = 1;
342 		if ((se_deve->def_pr_registered) && !(ignore_reg))
343 			registered_nexus = 1;
344 		break;
345 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
346 		we = 1;
347 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
348 		/*
349 		 * Each registered I_T Nexus is a reservation holder.
350 		 */
351 		all_reg = 1;
352 		if ((se_deve->def_pr_registered) && !(ignore_reg))
353 			registered_nexus = 1;
354 		break;
355 	default:
356 		return -EINVAL;
357 	}
358 	/*
359 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
360 	 */
361 	switch (cdb[0]) {
362 	case SECURITY_PROTOCOL_IN:
363 		if (registered_nexus)
364 			return 0;
365 		ret = (we) ? 0 : 1;
366 		break;
367 	case MODE_SENSE:
368 	case MODE_SENSE_10:
369 	case READ_ATTRIBUTE:
370 	case READ_BUFFER:
371 	case RECEIVE_DIAGNOSTIC:
372 		if (legacy) {
373 			ret = 1;
374 			break;
375 		}
376 		if (registered_nexus) {
377 			ret = 0;
378 			break;
379 		}
380 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
381 		break;
382 	case PERSISTENT_RESERVE_OUT:
383 		/*
384 		 * This follows PERSISTENT_RESERVE_OUT service actions that
385 		 * are allowed in the presence of various reservations.
386 		 * See spc4r17, table 46
387 		 */
388 		switch (cdb[1] & 0x1f) {
389 		case PRO_CLEAR:
390 		case PRO_PREEMPT:
391 		case PRO_PREEMPT_AND_ABORT:
392 			ret = (registered_nexus) ? 0 : 1;
393 			break;
394 		case PRO_REGISTER:
395 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
396 			ret = 0;
397 			break;
398 		case PRO_REGISTER_AND_MOVE:
399 		case PRO_RESERVE:
400 			ret = 1;
401 			break;
402 		case PRO_RELEASE:
403 			ret = (registered_nexus) ? 0 : 1;
404 			break;
405 		default:
406 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
407 				" action: 0x%02x\n", cdb[1] & 0x1f);
408 			return -EINVAL;
409 		}
410 		break;
411 	case RELEASE:
412 	case RELEASE_10:
413 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
414 		ret = 0;
415 		break;
416 	case RESERVE:
417 	case RESERVE_10:
418 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
419 		ret = 0;
420 		break;
421 	case TEST_UNIT_READY:
422 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
423 		break;
424 	case MAINTENANCE_IN:
425 		switch (cdb[1] & 0x1f) {
426 		case MI_MANAGEMENT_PROTOCOL_IN:
427 			if (registered_nexus) {
428 				ret = 0;
429 				break;
430 			}
431 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
432 			break;
433 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
434 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
435 			if (legacy) {
436 				ret = 1;
437 				break;
438 			}
439 			if (registered_nexus) {
440 				ret = 0;
441 				break;
442 			}
443 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
444 			break;
445 		case MI_REPORT_ALIASES:
446 		case MI_REPORT_IDENTIFYING_INFORMATION:
447 		case MI_REPORT_PRIORITY:
448 		case MI_REPORT_TARGET_PGS:
449 		case MI_REPORT_TIMESTAMP:
450 			ret = 0; /* Allowed */
451 			break;
452 		default:
453 			pr_err("Unknown MI Service Action: 0x%02x\n",
454 				(cdb[1] & 0x1f));
455 			return -EINVAL;
456 		}
457 		break;
458 	case ACCESS_CONTROL_IN:
459 	case ACCESS_CONTROL_OUT:
460 	case INQUIRY:
461 	case LOG_SENSE:
462 	case READ_MEDIA_SERIAL_NUMBER:
463 	case REPORT_LUNS:
464 	case REQUEST_SENSE:
465 	case PERSISTENT_RESERVE_IN:
466 		ret = 0; /*/ Allowed CDBs */
467 		break;
468 	default:
469 		other_cdb = 1;
470 		break;
471 	}
472 	/*
473 	 * Case where the CDB is explicitly allowed in the above switch
474 	 * statement.
475 	 */
476 	if (!ret && !other_cdb) {
477 		pr_debug("Allowing explicit CDB: 0x%02x for %s"
478 			" reservation holder\n", cdb[0],
479 			core_scsi3_pr_dump_type(pr_reg_type));
480 
481 		return ret;
482 	}
483 	/*
484 	 * Check if write exclusive initiator ports *NOT* holding the
485 	 * WRITE_EXCLUSIVE_* reservation.
486 	 */
487 	if (we && !registered_nexus) {
488 		if (cmd->data_direction == DMA_TO_DEVICE) {
489 			/*
490 			 * Conflict for write exclusive
491 			 */
492 			pr_debug("%s Conflict for unregistered nexus"
493 				" %s CDB: 0x%02x to %s reservation\n",
494 				transport_dump_cmd_direction(cmd),
495 				se_sess->se_node_acl->initiatorname, cdb[0],
496 				core_scsi3_pr_dump_type(pr_reg_type));
497 			return 1;
498 		} else {
499 			/*
500 			 * Allow non WRITE CDBs for all Write Exclusive
501 			 * PR TYPEs to pass for registered and
502 			 * non-registered_nexuxes NOT holding the reservation.
503 			 *
504 			 * We only make noise for the unregisterd nexuses,
505 			 * as we expect registered non-reservation holding
506 			 * nexuses to issue CDBs.
507 			 */
508 
509 			if (!registered_nexus) {
510 				pr_debug("Allowing implicit CDB: 0x%02x"
511 					" for %s reservation on unregistered"
512 					" nexus\n", cdb[0],
513 					core_scsi3_pr_dump_type(pr_reg_type));
514 			}
515 
516 			return 0;
517 		}
518 	} else if ((reg_only) || (all_reg)) {
519 		if (registered_nexus) {
520 			/*
521 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
522 			 * allow commands from registered nexuses.
523 			 */
524 
525 			pr_debug("Allowing implicit CDB: 0x%02x for %s"
526 				" reservation\n", cdb[0],
527 				core_scsi3_pr_dump_type(pr_reg_type));
528 
529 			return 0;
530 		}
531 	}
532 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
533 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
534 		(registered_nexus) ? "" : "un",
535 		se_sess->se_node_acl->initiatorname, cdb[0],
536 		core_scsi3_pr_dump_type(pr_reg_type));
537 
538 	return 1; /* Conflict by default */
539 }
540 
541 static sense_reason_t
542 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
543 {
544 	struct se_device *dev = cmd->se_dev;
545 	struct se_session *sess = cmd->se_sess;
546 	u32 pr_reg_type;
547 
548 	if (!dev->dev_pr_res_holder)
549 		return 0;
550 
551 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
552 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
553 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
554 		goto check_nonholder;
555 
556 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
557 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
558 		    sess->sess_bin_isid) {
559 			pr_reg_type |= 0x80000000;
560 			goto check_nonholder;
561 		}
562 	}
563 
564 	return 0;
565 
566 check_nonholder:
567 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type))
568 		return TCM_RESERVATION_CONFLICT;
569 	return 0;
570 }
571 
572 static u32 core_scsi3_pr_generation(struct se_device *dev)
573 {
574 	u32 prg;
575 
576 	/*
577 	 * PRGeneration field shall contain the value of a 32-bit wrapping
578 	 * counter mainted by the device server.
579 	 *
580 	 * Note that this is done regardless of Active Persist across
581 	 * Target PowerLoss (APTPL)
582 	 *
583 	 * See spc4r17 section 6.3.12 READ_KEYS service action
584 	 */
585 	spin_lock(&dev->dev_reservation_lock);
586 	prg = dev->t10_pr.pr_generation++;
587 	spin_unlock(&dev->dev_reservation_lock);
588 
589 	return prg;
590 }
591 
592 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
593 	struct se_device *dev,
594 	struct se_node_acl *nacl,
595 	struct se_dev_entry *deve,
596 	unsigned char *isid,
597 	u64 sa_res_key,
598 	int all_tg_pt,
599 	int aptpl)
600 {
601 	struct t10_pr_registration *pr_reg;
602 
603 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
604 	if (!pr_reg) {
605 		pr_err("Unable to allocate struct t10_pr_registration\n");
606 		return NULL;
607 	}
608 
609 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
610 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
611 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
612 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
613 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
614 	atomic_set(&pr_reg->pr_res_holders, 0);
615 	pr_reg->pr_reg_nacl = nacl;
616 	pr_reg->pr_reg_deve = deve;
617 	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
618 	pr_reg->pr_aptpl_target_lun = deve->se_lun->unpacked_lun;
619 	pr_reg->pr_res_key = sa_res_key;
620 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
621 	pr_reg->pr_reg_aptpl = aptpl;
622 	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
623 	/*
624 	 * If an ISID value for this SCSI Initiator Port exists,
625 	 * save it to the registration now.
626 	 */
627 	if (isid != NULL) {
628 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
629 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
630 		pr_reg->isid_present_at_reg = 1;
631 	}
632 
633 	return pr_reg;
634 }
635 
636 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
637 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
638 
639 /*
640  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
641  * modes.
642  */
643 static struct t10_pr_registration *__core_scsi3_alloc_registration(
644 	struct se_device *dev,
645 	struct se_node_acl *nacl,
646 	struct se_dev_entry *deve,
647 	unsigned char *isid,
648 	u64 sa_res_key,
649 	int all_tg_pt,
650 	int aptpl)
651 {
652 	struct se_dev_entry *deve_tmp;
653 	struct se_node_acl *nacl_tmp;
654 	struct se_port *port, *port_tmp;
655 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
656 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
657 	int ret;
658 	/*
659 	 * Create a registration for the I_T Nexus upon which the
660 	 * PROUT REGISTER was received.
661 	 */
662 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, deve, isid,
663 			sa_res_key, all_tg_pt, aptpl);
664 	if (!pr_reg)
665 		return NULL;
666 	/*
667 	 * Return pointer to pr_reg for ALL_TG_PT=0
668 	 */
669 	if (!all_tg_pt)
670 		return pr_reg;
671 	/*
672 	 * Create list of matching SCSI Initiator Port registrations
673 	 * for ALL_TG_PT=1
674 	 */
675 	spin_lock(&dev->se_port_lock);
676 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
677 		atomic_inc_mb(&port->sep_tg_pt_ref_cnt);
678 		spin_unlock(&dev->se_port_lock);
679 
680 		spin_lock_bh(&port->sep_alua_lock);
681 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
682 					alua_port_list) {
683 			/*
684 			 * This pointer will be NULL for demo mode MappedLUNs
685 			 * that have not been make explicit via a ConfigFS
686 			 * MappedLUN group for the SCSI Initiator Node ACL.
687 			 */
688 			if (!deve_tmp->se_lun_acl)
689 				continue;
690 
691 			nacl_tmp = deve_tmp->se_lun_acl->se_lun_nacl;
692 			/*
693 			 * Skip the matching struct se_node_acl that is allocated
694 			 * above..
695 			 */
696 			if (nacl == nacl_tmp)
697 				continue;
698 			/*
699 			 * Only perform PR registrations for target ports on
700 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
701 			 * arrived.
702 			 */
703 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
704 				continue;
705 			/*
706 			 * Look for a matching Initiator Node ACL in ASCII format
707 			 */
708 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
709 				continue;
710 
711 			atomic_inc_mb(&deve_tmp->pr_ref_count);
712 			spin_unlock_bh(&port->sep_alua_lock);
713 			/*
714 			 * Grab a configfs group dependency that is released
715 			 * for the exception path at label out: below, or upon
716 			 * completion of adding ALL_TG_PT=1 registrations in
717 			 * __core_scsi3_add_registration()
718 			 */
719 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
720 			if (ret < 0) {
721 				pr_err("core_scsi3_lunacl_depend"
722 						"_item() failed\n");
723 				atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
724 				atomic_dec_mb(&deve_tmp->pr_ref_count);
725 				goto out;
726 			}
727 			/*
728 			 * Located a matching SCSI Initiator Port on a different
729 			 * port, allocate the pr_reg_atp and attach it to the
730 			 * pr_reg->pr_reg_atp_list that will be processed once
731 			 * the original *pr_reg is processed in
732 			 * __core_scsi3_add_registration()
733 			 */
734 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
735 						nacl_tmp, deve_tmp, NULL,
736 						sa_res_key, all_tg_pt, aptpl);
737 			if (!pr_reg_atp) {
738 				atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
739 				atomic_dec_mb(&deve_tmp->pr_ref_count);
740 				core_scsi3_lunacl_undepend_item(deve_tmp);
741 				goto out;
742 			}
743 
744 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
745 				      &pr_reg->pr_reg_atp_list);
746 			spin_lock_bh(&port->sep_alua_lock);
747 		}
748 		spin_unlock_bh(&port->sep_alua_lock);
749 
750 		spin_lock(&dev->se_port_lock);
751 		atomic_dec_mb(&port->sep_tg_pt_ref_cnt);
752 	}
753 	spin_unlock(&dev->se_port_lock);
754 
755 	return pr_reg;
756 out:
757 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
758 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
759 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
760 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
761 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
762 	}
763 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
764 	return NULL;
765 }
766 
767 int core_scsi3_alloc_aptpl_registration(
768 	struct t10_reservation *pr_tmpl,
769 	u64 sa_res_key,
770 	unsigned char *i_port,
771 	unsigned char *isid,
772 	u32 mapped_lun,
773 	unsigned char *t_port,
774 	u16 tpgt,
775 	u32 target_lun,
776 	int res_holder,
777 	int all_tg_pt,
778 	u8 type)
779 {
780 	struct t10_pr_registration *pr_reg;
781 
782 	if (!i_port || !t_port || !sa_res_key) {
783 		pr_err("Illegal parameters for APTPL registration\n");
784 		return -EINVAL;
785 	}
786 
787 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
788 	if (!pr_reg) {
789 		pr_err("Unable to allocate struct t10_pr_registration\n");
790 		return -ENOMEM;
791 	}
792 
793 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
794 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
795 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
796 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
797 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
798 	atomic_set(&pr_reg->pr_res_holders, 0);
799 	pr_reg->pr_reg_nacl = NULL;
800 	pr_reg->pr_reg_deve = NULL;
801 	pr_reg->pr_res_mapped_lun = mapped_lun;
802 	pr_reg->pr_aptpl_target_lun = target_lun;
803 	pr_reg->pr_res_key = sa_res_key;
804 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
805 	pr_reg->pr_reg_aptpl = 1;
806 	pr_reg->pr_reg_tg_pt_lun = NULL;
807 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
808 	pr_reg->pr_res_type = type;
809 	/*
810 	 * If an ISID value had been saved in APTPL metadata for this
811 	 * SCSI Initiator Port, restore it now.
812 	 */
813 	if (isid != NULL) {
814 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
815 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
816 		pr_reg->isid_present_at_reg = 1;
817 	}
818 	/*
819 	 * Copy the i_port and t_port information from caller.
820 	 */
821 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
822 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
823 	pr_reg->pr_reg_tpgt = tpgt;
824 	/*
825 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
826 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
827 	 * the Initiator Node LUN ACL from the fabric module is created for
828 	 * this registration.
829 	 */
830 	pr_reg->pr_res_holder = res_holder;
831 
832 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
833 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
834 			" metadata\n", (res_holder) ? "+reservation" : "");
835 	return 0;
836 }
837 
838 static void core_scsi3_aptpl_reserve(
839 	struct se_device *dev,
840 	struct se_portal_group *tpg,
841 	struct se_node_acl *node_acl,
842 	struct t10_pr_registration *pr_reg)
843 {
844 	char i_buf[PR_REG_ISID_ID_LEN];
845 
846 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
847 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
848 
849 	spin_lock(&dev->dev_reservation_lock);
850 	dev->dev_pr_res_holder = pr_reg;
851 	spin_unlock(&dev->dev_reservation_lock);
852 
853 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
854 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
855 		tpg->se_tpg_tfo->get_fabric_name(),
856 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
857 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
858 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
859 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
860 		i_buf);
861 }
862 
863 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
864 				struct t10_pr_registration *, enum register_type, int);
865 
866 static int __core_scsi3_check_aptpl_registration(
867 	struct se_device *dev,
868 	struct se_portal_group *tpg,
869 	struct se_lun *lun,
870 	u32 target_lun,
871 	struct se_node_acl *nacl,
872 	struct se_dev_entry *deve)
873 {
874 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
875 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
876 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
877 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
878 	u16 tpgt;
879 
880 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
881 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
882 	/*
883 	 * Copy Initiator Port information from struct se_node_acl
884 	 */
885 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
886 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
887 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
888 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
889 	/*
890 	 * Look for the matching registrations+reservation from those
891 	 * created from APTPL metadata.  Note that multiple registrations
892 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
893 	 * TransportIDs.
894 	 */
895 	spin_lock(&pr_tmpl->aptpl_reg_lock);
896 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
897 				pr_reg_aptpl_list) {
898 
899 		if (!strcmp(pr_reg->pr_iport, i_port) &&
900 		     (pr_reg->pr_res_mapped_lun == deve->mapped_lun) &&
901 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
902 		     (pr_reg->pr_reg_tpgt == tpgt) &&
903 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
904 
905 			pr_reg->pr_reg_nacl = nacl;
906 			pr_reg->pr_reg_deve = deve;
907 			pr_reg->pr_reg_tg_pt_lun = lun;
908 
909 			list_del(&pr_reg->pr_reg_aptpl_list);
910 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
911 			/*
912 			 * At this point all of the pointers in *pr_reg will
913 			 * be setup, so go ahead and add the registration.
914 			 */
915 
916 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
917 			/*
918 			 * If this registration is the reservation holder,
919 			 * make that happen now..
920 			 */
921 			if (pr_reg->pr_res_holder)
922 				core_scsi3_aptpl_reserve(dev, tpg,
923 						nacl, pr_reg);
924 			/*
925 			 * Reenable pr_aptpl_active to accept new metadata
926 			 * updates once the SCSI device is active again..
927 			 */
928 			spin_lock(&pr_tmpl->aptpl_reg_lock);
929 			pr_tmpl->pr_aptpl_active = 1;
930 		}
931 	}
932 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
933 
934 	return 0;
935 }
936 
937 int core_scsi3_check_aptpl_registration(
938 	struct se_device *dev,
939 	struct se_portal_group *tpg,
940 	struct se_lun *lun,
941 	struct se_node_acl *nacl,
942 	u32 mapped_lun)
943 {
944 	struct se_dev_entry *deve = nacl->device_list[mapped_lun];
945 
946 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
947 		return 0;
948 
949 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
950 				lun->unpacked_lun, nacl, deve);
951 }
952 
953 static void __core_scsi3_dump_registration(
954 	struct target_core_fabric_ops *tfo,
955 	struct se_device *dev,
956 	struct se_node_acl *nacl,
957 	struct t10_pr_registration *pr_reg,
958 	enum register_type register_type)
959 {
960 	struct se_portal_group *se_tpg = nacl->se_tpg;
961 	char i_buf[PR_REG_ISID_ID_LEN];
962 
963 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
964 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
965 
966 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
967 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == REGISTER_AND_MOVE) ?
968 		"_AND_MOVE" : (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ?
969 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
970 		i_buf);
971 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
972 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
973 		tfo->tpg_get_tag(se_tpg));
974 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
975 		" Port(s)\n",  tfo->get_fabric_name(),
976 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
977 		dev->transport->name);
978 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
979 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
980 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
981 		pr_reg->pr_reg_aptpl);
982 }
983 
984 /*
985  * this function can be called with struct se_device->dev_reservation_lock
986  * when register_move = 1
987  */
988 static void __core_scsi3_add_registration(
989 	struct se_device *dev,
990 	struct se_node_acl *nacl,
991 	struct t10_pr_registration *pr_reg,
992 	enum register_type register_type,
993 	int register_move)
994 {
995 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
996 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
997 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
998 
999 	/*
1000 	 * Increment PRgeneration counter for struct se_device upon a successful
1001 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1002 	 *
1003 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1004 	 * action, the struct se_device->dev_reservation_lock will already be held,
1005 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1006 	 * for the REGISTER.
1007 	 */
1008 	pr_reg->pr_res_generation = (register_move) ?
1009 			dev->t10_pr.pr_generation++ :
1010 			core_scsi3_pr_generation(dev);
1011 
1012 	spin_lock(&pr_tmpl->registration_lock);
1013 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1014 	pr_reg->pr_reg_deve->def_pr_registered = 1;
1015 
1016 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1017 	spin_unlock(&pr_tmpl->registration_lock);
1018 	/*
1019 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1020 	 */
1021 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1022 		return;
1023 	/*
1024 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1025 	 * allocated in __core_scsi3_alloc_registration()
1026 	 */
1027 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1028 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1029 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1030 
1031 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1032 
1033 		spin_lock(&pr_tmpl->registration_lock);
1034 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1035 			      &pr_tmpl->registration_list);
1036 		pr_reg_tmp->pr_reg_deve->def_pr_registered = 1;
1037 
1038 		__core_scsi3_dump_registration(tfo, dev,
1039 				pr_reg_tmp->pr_reg_nacl, pr_reg_tmp,
1040 				register_type);
1041 		spin_unlock(&pr_tmpl->registration_lock);
1042 		/*
1043 		 * Drop configfs group dependency reference from
1044 		 * __core_scsi3_alloc_registration()
1045 		 */
1046 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1047 	}
1048 }
1049 
1050 static int core_scsi3_alloc_registration(
1051 	struct se_device *dev,
1052 	struct se_node_acl *nacl,
1053 	struct se_dev_entry *deve,
1054 	unsigned char *isid,
1055 	u64 sa_res_key,
1056 	int all_tg_pt,
1057 	int aptpl,
1058 	enum register_type register_type,
1059 	int register_move)
1060 {
1061 	struct t10_pr_registration *pr_reg;
1062 
1063 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, deve, isid,
1064 			sa_res_key, all_tg_pt, aptpl);
1065 	if (!pr_reg)
1066 		return -EPERM;
1067 
1068 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1069 			register_type, register_move);
1070 	return 0;
1071 }
1072 
1073 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1074 	struct se_device *dev,
1075 	struct se_node_acl *nacl,
1076 	unsigned char *isid)
1077 {
1078 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1079 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1080 	struct se_portal_group *tpg;
1081 
1082 	spin_lock(&pr_tmpl->registration_lock);
1083 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1084 			&pr_tmpl->registration_list, pr_reg_list) {
1085 		/*
1086 		 * First look for a matching struct se_node_acl
1087 		 */
1088 		if (pr_reg->pr_reg_nacl != nacl)
1089 			continue;
1090 
1091 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1092 		/*
1093 		 * If this registration does NOT contain a fabric provided
1094 		 * ISID, then we have found a match.
1095 		 */
1096 		if (!pr_reg->isid_present_at_reg) {
1097 			/*
1098 			 * Determine if this SCSI device server requires that
1099 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1100 			 * for fabric modules (iSCSI) requiring them.
1101 			 */
1102 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1103 				if (dev->dev_attrib.enforce_pr_isids)
1104 					continue;
1105 			}
1106 			atomic_inc_mb(&pr_reg->pr_res_holders);
1107 			spin_unlock(&pr_tmpl->registration_lock);
1108 			return pr_reg;
1109 		}
1110 		/*
1111 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1112 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1113 		 * matching ISID to be provided by the local SCSI Initiator Port.
1114 		 */
1115 		if (!isid)
1116 			continue;
1117 		if (strcmp(isid, pr_reg->pr_reg_isid))
1118 			continue;
1119 
1120 		atomic_inc_mb(&pr_reg->pr_res_holders);
1121 		spin_unlock(&pr_tmpl->registration_lock);
1122 		return pr_reg;
1123 	}
1124 	spin_unlock(&pr_tmpl->registration_lock);
1125 
1126 	return NULL;
1127 }
1128 
1129 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1130 	struct se_device *dev,
1131 	struct se_node_acl *nacl,
1132 	struct se_session *sess)
1133 {
1134 	struct se_portal_group *tpg = nacl->se_tpg;
1135 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1136 
1137 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1138 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1139 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1140 					PR_REG_ISID_LEN);
1141 		isid_ptr = &buf[0];
1142 	}
1143 
1144 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1145 }
1146 
1147 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1148 {
1149 	atomic_dec_mb(&pr_reg->pr_res_holders);
1150 }
1151 
1152 static int core_scsi3_check_implicit_release(
1153 	struct se_device *dev,
1154 	struct t10_pr_registration *pr_reg)
1155 {
1156 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1157 	struct t10_pr_registration *pr_res_holder;
1158 	int ret = 0;
1159 
1160 	spin_lock(&dev->dev_reservation_lock);
1161 	pr_res_holder = dev->dev_pr_res_holder;
1162 	if (!pr_res_holder) {
1163 		spin_unlock(&dev->dev_reservation_lock);
1164 		return ret;
1165 	}
1166 	if (pr_res_holder == pr_reg) {
1167 		/*
1168 		 * Perform an implicit RELEASE if the registration that
1169 		 * is being released is holding the reservation.
1170 		 *
1171 		 * From spc4r17, section 5.7.11.1:
1172 		 *
1173 		 * e) If the I_T nexus is the persistent reservation holder
1174 		 *    and the persistent reservation is not an all registrants
1175 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1176 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1177 		 *    service action with the SERVICE ACTION RESERVATION KEY
1178 		 *    field set to zero (see 5.7.11.3).
1179 		 */
1180 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0);
1181 		ret = 1;
1182 		/*
1183 		 * For 'All Registrants' reservation types, all existing
1184 		 * registrations are still processed as reservation holders
1185 		 * in core_scsi3_pr_seq_non_holder() after the initial
1186 		 * reservation holder is implicitly released here.
1187 		 */
1188 	} else if (pr_reg->pr_reg_all_tg_pt &&
1189 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1190 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1191 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1192 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1193 			" UNREGISTER while existing reservation with matching"
1194 			" key 0x%016Lx is present from another SCSI Initiator"
1195 			" Port\n", pr_reg->pr_res_key);
1196 		ret = -EPERM;
1197 	}
1198 	spin_unlock(&dev->dev_reservation_lock);
1199 
1200 	return ret;
1201 }
1202 
1203 /*
1204  * Called with struct t10_reservation->registration_lock held.
1205  */
1206 static void __core_scsi3_free_registration(
1207 	struct se_device *dev,
1208 	struct t10_pr_registration *pr_reg,
1209 	struct list_head *preempt_and_abort_list,
1210 	int dec_holders)
1211 {
1212 	struct target_core_fabric_ops *tfo =
1213 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1214 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1215 	char i_buf[PR_REG_ISID_ID_LEN];
1216 
1217 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1218 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1219 
1220 	pr_reg->pr_reg_deve->def_pr_registered = 0;
1221 	pr_reg->pr_reg_deve->pr_res_key = 0;
1222 	list_del(&pr_reg->pr_reg_list);
1223 	/*
1224 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1225 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1226 	 */
1227 	if (dec_holders)
1228 		core_scsi3_put_pr_reg(pr_reg);
1229 	/*
1230 	 * Wait until all reference from any other I_T nexuses for this
1231 	 * *pr_reg have been released.  Because list_del() is called above,
1232 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1233 	 * count back to zero, and we release *pr_reg.
1234 	 */
1235 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1236 		spin_unlock(&pr_tmpl->registration_lock);
1237 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1238 				tfo->get_fabric_name());
1239 		cpu_relax();
1240 		spin_lock(&pr_tmpl->registration_lock);
1241 	}
1242 
1243 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1244 		" Node: %s%s\n", tfo->get_fabric_name(),
1245 		pr_reg->pr_reg_nacl->initiatorname,
1246 		i_buf);
1247 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1248 		" Port(s)\n", tfo->get_fabric_name(),
1249 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1250 		dev->transport->name);
1251 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1252 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1253 		pr_reg->pr_res_generation);
1254 
1255 	if (!preempt_and_abort_list) {
1256 		pr_reg->pr_reg_deve = NULL;
1257 		pr_reg->pr_reg_nacl = NULL;
1258 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1259 		return;
1260 	}
1261 	/*
1262 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1263 	 * are released once the ABORT_TASK_SET has completed..
1264 	 */
1265 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1266 }
1267 
1268 void core_scsi3_free_pr_reg_from_nacl(
1269 	struct se_device *dev,
1270 	struct se_node_acl *nacl)
1271 {
1272 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1273 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1274 	/*
1275 	 * If the passed se_node_acl matches the reservation holder,
1276 	 * release the reservation.
1277 	 */
1278 	spin_lock(&dev->dev_reservation_lock);
1279 	pr_res_holder = dev->dev_pr_res_holder;
1280 	if ((pr_res_holder != NULL) &&
1281 	    (pr_res_holder->pr_reg_nacl == nacl))
1282 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0);
1283 	spin_unlock(&dev->dev_reservation_lock);
1284 	/*
1285 	 * Release any registration associated with the struct se_node_acl.
1286 	 */
1287 	spin_lock(&pr_tmpl->registration_lock);
1288 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1289 			&pr_tmpl->registration_list, pr_reg_list) {
1290 
1291 		if (pr_reg->pr_reg_nacl != nacl)
1292 			continue;
1293 
1294 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1295 	}
1296 	spin_unlock(&pr_tmpl->registration_lock);
1297 }
1298 
1299 void core_scsi3_free_all_registrations(
1300 	struct se_device *dev)
1301 {
1302 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1303 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1304 
1305 	spin_lock(&dev->dev_reservation_lock);
1306 	pr_res_holder = dev->dev_pr_res_holder;
1307 	if (pr_res_holder != NULL) {
1308 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1309 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1310 				pr_res_holder, 0);
1311 	}
1312 	spin_unlock(&dev->dev_reservation_lock);
1313 
1314 	spin_lock(&pr_tmpl->registration_lock);
1315 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1316 			&pr_tmpl->registration_list, pr_reg_list) {
1317 
1318 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1319 	}
1320 	spin_unlock(&pr_tmpl->registration_lock);
1321 
1322 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1323 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1324 				pr_reg_aptpl_list) {
1325 		list_del(&pr_reg->pr_reg_aptpl_list);
1326 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1327 	}
1328 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1329 }
1330 
1331 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1332 {
1333 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1334 			&tpg->tpg_group.cg_item);
1335 }
1336 
1337 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1338 {
1339 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1340 			&tpg->tpg_group.cg_item);
1341 
1342 	atomic_dec_mb(&tpg->tpg_pr_ref_count);
1343 }
1344 
1345 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1346 {
1347 	struct se_portal_group *tpg = nacl->se_tpg;
1348 
1349 	if (nacl->dynamic_node_acl)
1350 		return 0;
1351 
1352 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1353 			&nacl->acl_group.cg_item);
1354 }
1355 
1356 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1357 {
1358 	struct se_portal_group *tpg = nacl->se_tpg;
1359 
1360 	if (nacl->dynamic_node_acl) {
1361 		atomic_dec_mb(&nacl->acl_pr_ref_count);
1362 		return;
1363 	}
1364 
1365 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1366 			&nacl->acl_group.cg_item);
1367 
1368 	atomic_dec_mb(&nacl->acl_pr_ref_count);
1369 }
1370 
1371 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1372 {
1373 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1374 	struct se_node_acl *nacl;
1375 	struct se_portal_group *tpg;
1376 	/*
1377 	 * For nacl->dynamic_node_acl=1
1378 	 */
1379 	if (!lun_acl)
1380 		return 0;
1381 
1382 	nacl = lun_acl->se_lun_nacl;
1383 	tpg = nacl->se_tpg;
1384 
1385 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1386 			&lun_acl->se_lun_group.cg_item);
1387 }
1388 
1389 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1390 {
1391 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1392 	struct se_node_acl *nacl;
1393 	struct se_portal_group *tpg;
1394 	/*
1395 	 * For nacl->dynamic_node_acl=1
1396 	 */
1397 	if (!lun_acl) {
1398 		atomic_dec_mb(&se_deve->pr_ref_count);
1399 		return;
1400 	}
1401 	nacl = lun_acl->se_lun_nacl;
1402 	tpg = nacl->se_tpg;
1403 
1404 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1405 			&lun_acl->se_lun_group.cg_item);
1406 
1407 	atomic_dec_mb(&se_deve->pr_ref_count);
1408 }
1409 
1410 static sense_reason_t
1411 core_scsi3_decode_spec_i_port(
1412 	struct se_cmd *cmd,
1413 	struct se_portal_group *tpg,
1414 	unsigned char *l_isid,
1415 	u64 sa_res_key,
1416 	int all_tg_pt,
1417 	int aptpl)
1418 {
1419 	struct se_device *dev = cmd->se_dev;
1420 	struct se_port *tmp_port;
1421 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1422 	struct se_session *se_sess = cmd->se_sess;
1423 	struct se_node_acl *dest_node_acl = NULL;
1424 	struct se_dev_entry *dest_se_deve = NULL, *local_se_deve;
1425 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1426 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1427 	LIST_HEAD(tid_dest_list);
1428 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1429 	struct target_core_fabric_ops *tmp_tf_ops;
1430 	unsigned char *buf;
1431 	unsigned char *ptr, *i_str = NULL, proto_ident, tmp_proto_ident;
1432 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
1433 	sense_reason_t ret;
1434 	u32 tpdl, tid_len = 0;
1435 	int dest_local_nexus;
1436 	u32 dest_rtpi = 0;
1437 
1438 	memset(dest_iport, 0, 64);
1439 
1440 	local_se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
1441 	/*
1442 	 * Allocate a struct pr_transport_id_holder and setup the
1443 	 * local_node_acl and local_se_deve pointers and add to
1444 	 * struct list_head tid_dest_list for add registration
1445 	 * processing in the loop of tid_dest_list below.
1446 	 */
1447 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1448 	if (!tidh_new) {
1449 		pr_err("Unable to allocate tidh_new\n");
1450 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1451 	}
1452 	INIT_LIST_HEAD(&tidh_new->dest_list);
1453 	tidh_new->dest_tpg = tpg;
1454 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1455 	tidh_new->dest_se_deve = local_se_deve;
1456 
1457 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1458 				se_sess->se_node_acl, local_se_deve, l_isid,
1459 				sa_res_key, all_tg_pt, aptpl);
1460 	if (!local_pr_reg) {
1461 		kfree(tidh_new);
1462 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1463 	}
1464 	tidh_new->dest_pr_reg = local_pr_reg;
1465 	/*
1466 	 * The local I_T nexus does not hold any configfs dependances,
1467 	 * so we set tid_h->dest_local_nexus=1 to prevent the
1468 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1469 	 */
1470 	tidh_new->dest_local_nexus = 1;
1471 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1472 
1473 	if (cmd->data_length < 28) {
1474 		pr_warn("SPC-PR: Received PR OUT parameter list"
1475 			" length too small: %u\n", cmd->data_length);
1476 		ret = TCM_INVALID_PARAMETER_LIST;
1477 		goto out;
1478 	}
1479 
1480 	buf = transport_kmap_data_sg(cmd);
1481 	if (!buf) {
1482 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1483 		goto out;
1484 	}
1485 
1486 	/*
1487 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1488 	 * first extract TransportID Parameter Data Length, and make sure
1489 	 * the value matches up to the SCSI expected data transfer length.
1490 	 */
1491 	tpdl = (buf[24] & 0xff) << 24;
1492 	tpdl |= (buf[25] & 0xff) << 16;
1493 	tpdl |= (buf[26] & 0xff) << 8;
1494 	tpdl |= buf[27] & 0xff;
1495 
1496 	if ((tpdl + 28) != cmd->data_length) {
1497 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1498 			" does not equal CDB data_length: %u\n", tpdl,
1499 			cmd->data_length);
1500 		ret = TCM_INVALID_PARAMETER_LIST;
1501 		goto out_unmap;
1502 	}
1503 	/*
1504 	 * Start processing the received transport IDs using the
1505 	 * receiving I_T Nexus portal's fabric dependent methods to
1506 	 * obtain the SCSI Initiator Port/Device Identifiers.
1507 	 */
1508 	ptr = &buf[28];
1509 
1510 	while (tpdl > 0) {
1511 		proto_ident = (ptr[0] & 0x0f);
1512 		dest_tpg = NULL;
1513 
1514 		spin_lock(&dev->se_port_lock);
1515 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1516 			tmp_tpg = tmp_port->sep_tpg;
1517 			if (!tmp_tpg)
1518 				continue;
1519 			tmp_tf_ops = tmp_tpg->se_tpg_tfo;
1520 			if (!tmp_tf_ops)
1521 				continue;
1522 			if (!tmp_tf_ops->get_fabric_proto_ident ||
1523 			    !tmp_tf_ops->tpg_parse_pr_out_transport_id)
1524 				continue;
1525 			/*
1526 			 * Look for the matching proto_ident provided by
1527 			 * the received TransportID
1528 			 */
1529 			tmp_proto_ident = tmp_tf_ops->get_fabric_proto_ident(tmp_tpg);
1530 			if (tmp_proto_ident != proto_ident)
1531 				continue;
1532 			dest_rtpi = tmp_port->sep_rtpi;
1533 
1534 			i_str = tmp_tf_ops->tpg_parse_pr_out_transport_id(
1535 					tmp_tpg, (const char *)ptr, &tid_len,
1536 					&iport_ptr);
1537 			if (!i_str)
1538 				continue;
1539 
1540 			atomic_inc_mb(&tmp_tpg->tpg_pr_ref_count);
1541 			spin_unlock(&dev->se_port_lock);
1542 
1543 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1544 				pr_err(" core_scsi3_tpg_depend_item()"
1545 					" for tmp_tpg\n");
1546 				atomic_dec_mb(&tmp_tpg->tpg_pr_ref_count);
1547 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1548 				goto out_unmap;
1549 			}
1550 			/*
1551 			 * Locate the destination initiator ACL to be registered
1552 			 * from the decoded fabric module specific TransportID
1553 			 * at *i_str.
1554 			 */
1555 			spin_lock_irq(&tmp_tpg->acl_node_lock);
1556 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1557 						tmp_tpg, i_str);
1558 			if (dest_node_acl)
1559 				atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
1560 			spin_unlock_irq(&tmp_tpg->acl_node_lock);
1561 
1562 			if (!dest_node_acl) {
1563 				core_scsi3_tpg_undepend_item(tmp_tpg);
1564 				spin_lock(&dev->se_port_lock);
1565 				continue;
1566 			}
1567 
1568 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1569 				pr_err("configfs_depend_item() failed"
1570 					" for dest_node_acl->acl_group\n");
1571 				atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
1572 				core_scsi3_tpg_undepend_item(tmp_tpg);
1573 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1574 				goto out_unmap;
1575 			}
1576 
1577 			dest_tpg = tmp_tpg;
1578 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1579 				" %s Port RTPI: %hu\n",
1580 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1581 				dest_node_acl->initiatorname, dest_rtpi);
1582 
1583 			spin_lock(&dev->se_port_lock);
1584 			break;
1585 		}
1586 		spin_unlock(&dev->se_port_lock);
1587 
1588 		if (!dest_tpg) {
1589 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1590 					" dest_tpg\n");
1591 			ret = TCM_INVALID_PARAMETER_LIST;
1592 			goto out_unmap;
1593 		}
1594 
1595 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1596 			" tid_len: %d for %s + %s\n",
1597 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1598 			tpdl, tid_len, i_str, iport_ptr);
1599 
1600 		if (tid_len > tpdl) {
1601 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1602 				" %u for Transport ID: %s\n", tid_len, ptr);
1603 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1604 			core_scsi3_tpg_undepend_item(dest_tpg);
1605 			ret = TCM_INVALID_PARAMETER_LIST;
1606 			goto out_unmap;
1607 		}
1608 		/*
1609 		 * Locate the desintation struct se_dev_entry pointer for matching
1610 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1611 		 * Target Port.
1612 		 */
1613 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1614 					dest_rtpi);
1615 		if (!dest_se_deve) {
1616 			pr_err("Unable to locate %s dest_se_deve"
1617 				" from destination RTPI: %hu\n",
1618 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1619 				dest_rtpi);
1620 
1621 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1622 			core_scsi3_tpg_undepend_item(dest_tpg);
1623 			ret = TCM_INVALID_PARAMETER_LIST;
1624 			goto out_unmap;
1625 		}
1626 
1627 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1628 			pr_err("core_scsi3_lunacl_depend_item()"
1629 					" failed\n");
1630 			atomic_dec_mb(&dest_se_deve->pr_ref_count);
1631 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1632 			core_scsi3_tpg_undepend_item(dest_tpg);
1633 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1634 			goto out_unmap;
1635 		}
1636 
1637 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1638 			" dest_se_deve mapped_lun: %u\n",
1639 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1640 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1641 
1642 		/*
1643 		 * Skip any TransportIDs that already have a registration for
1644 		 * this target port.
1645 		 */
1646 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1647 					iport_ptr);
1648 		if (pr_reg_e) {
1649 			core_scsi3_put_pr_reg(pr_reg_e);
1650 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1651 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1652 			core_scsi3_tpg_undepend_item(dest_tpg);
1653 			ptr += tid_len;
1654 			tpdl -= tid_len;
1655 			tid_len = 0;
1656 			continue;
1657 		}
1658 		/*
1659 		 * Allocate a struct pr_transport_id_holder and setup
1660 		 * the dest_node_acl and dest_se_deve pointers for the
1661 		 * loop below.
1662 		 */
1663 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1664 				GFP_KERNEL);
1665 		if (!tidh_new) {
1666 			pr_err("Unable to allocate tidh_new\n");
1667 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1668 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1669 			core_scsi3_tpg_undepend_item(dest_tpg);
1670 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1671 			goto out_unmap;
1672 		}
1673 		INIT_LIST_HEAD(&tidh_new->dest_list);
1674 		tidh_new->dest_tpg = dest_tpg;
1675 		tidh_new->dest_node_acl = dest_node_acl;
1676 		tidh_new->dest_se_deve = dest_se_deve;
1677 
1678 		/*
1679 		 * Allocate, but do NOT add the registration for the
1680 		 * TransportID referenced SCSI Initiator port.  This
1681 		 * done because of the following from spc4r17 in section
1682 		 * 6.14.3 wrt SPEC_I_PT:
1683 		 *
1684 		 * "If a registration fails for any initiator port (e.g., if th
1685 		 * logical unit does not have enough resources available to
1686 		 * hold the registration information), no registrations shall be
1687 		 * made, and the command shall be terminated with
1688 		 * CHECK CONDITION status."
1689 		 *
1690 		 * That means we call __core_scsi3_alloc_registration() here,
1691 		 * and then call __core_scsi3_add_registration() in the
1692 		 * 2nd loop which will never fail.
1693 		 */
1694 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1695 				dest_node_acl, dest_se_deve, iport_ptr,
1696 				sa_res_key, all_tg_pt, aptpl);
1697 		if (!dest_pr_reg) {
1698 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1699 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1700 			core_scsi3_tpg_undepend_item(dest_tpg);
1701 			kfree(tidh_new);
1702 			ret = TCM_INVALID_PARAMETER_LIST;
1703 			goto out_unmap;
1704 		}
1705 		tidh_new->dest_pr_reg = dest_pr_reg;
1706 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1707 
1708 		ptr += tid_len;
1709 		tpdl -= tid_len;
1710 		tid_len = 0;
1711 
1712 	}
1713 
1714 	transport_kunmap_data_sg(cmd);
1715 
1716 	/*
1717 	 * Go ahead and create a registrations from tid_dest_list for the
1718 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1719 	 * and dest_se_deve.
1720 	 *
1721 	 * The SA Reservation Key from the PROUT is set for the
1722 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1723 	 * means that the TransportID Initiator port will be
1724 	 * registered on all of the target ports in the SCSI target device
1725 	 * ALL_TG_PT=0 means the registration will only be for the
1726 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1727 	 * was received.
1728 	 */
1729 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1730 		dest_tpg = tidh->dest_tpg;
1731 		dest_node_acl = tidh->dest_node_acl;
1732 		dest_se_deve = tidh->dest_se_deve;
1733 		dest_pr_reg = tidh->dest_pr_reg;
1734 		dest_local_nexus = tidh->dest_local_nexus;
1735 
1736 		list_del(&tidh->dest_list);
1737 		kfree(tidh);
1738 
1739 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1740 		core_pr_dump_initiator_port(dest_pr_reg, i_buf, PR_REG_ISID_ID_LEN);
1741 
1742 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1743 					dest_pr_reg, 0, 0);
1744 
1745 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1746 			" registered Transport ID for Node: %s%s Mapped LUN:"
1747 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1748 			dest_node_acl->initiatorname, i_buf, dest_se_deve->mapped_lun);
1749 
1750 		if (dest_local_nexus)
1751 			continue;
1752 
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 	}
1757 
1758 	return 0;
1759 out_unmap:
1760 	transport_kunmap_data_sg(cmd);
1761 out:
1762 	/*
1763 	 * For the failure case, release everything from tid_dest_list
1764 	 * including *dest_pr_reg and the configfs dependances..
1765 	 */
1766 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1767 		dest_tpg = tidh->dest_tpg;
1768 		dest_node_acl = tidh->dest_node_acl;
1769 		dest_se_deve = tidh->dest_se_deve;
1770 		dest_pr_reg = tidh->dest_pr_reg;
1771 		dest_local_nexus = tidh->dest_local_nexus;
1772 
1773 		list_del(&tidh->dest_list);
1774 		kfree(tidh);
1775 		/*
1776 		 * Release any extra ALL_TG_PT=1 registrations for
1777 		 * the SPEC_I_PT=1 case.
1778 		 */
1779 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1780 				&dest_pr_reg->pr_reg_atp_list,
1781 				pr_reg_atp_mem_list) {
1782 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1783 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1784 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1785 		}
1786 
1787 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1788 
1789 		if (dest_local_nexus)
1790 			continue;
1791 
1792 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1793 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1794 		core_scsi3_tpg_undepend_item(dest_tpg);
1795 	}
1796 	return ret;
1797 }
1798 
1799 static int core_scsi3_update_aptpl_buf(
1800 	struct se_device *dev,
1801 	unsigned char *buf,
1802 	u32 pr_aptpl_buf_len)
1803 {
1804 	struct se_lun *lun;
1805 	struct se_portal_group *tpg;
1806 	struct t10_pr_registration *pr_reg;
1807 	unsigned char tmp[512], isid_buf[32];
1808 	ssize_t len = 0;
1809 	int reg_count = 0;
1810 	int ret = 0;
1811 
1812 	spin_lock(&dev->dev_reservation_lock);
1813 	spin_lock(&dev->t10_pr.registration_lock);
1814 	/*
1815 	 * Walk the registration list..
1816 	 */
1817 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1818 			pr_reg_list) {
1819 
1820 		tmp[0] = '\0';
1821 		isid_buf[0] = '\0';
1822 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1823 		lun = pr_reg->pr_reg_tg_pt_lun;
1824 		/*
1825 		 * Write out any ISID value to APTPL metadata that was included
1826 		 * in the original registration.
1827 		 */
1828 		if (pr_reg->isid_present_at_reg)
1829 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1830 					pr_reg->pr_reg_isid);
1831 		/*
1832 		 * Include special metadata if the pr_reg matches the
1833 		 * reservation holder.
1834 		 */
1835 		if (dev->dev_pr_res_holder == pr_reg) {
1836 			snprintf(tmp, 512, "PR_REG_START: %d"
1837 				"\ninitiator_fabric=%s\n"
1838 				"initiator_node=%s\n%s"
1839 				"sa_res_key=%llu\n"
1840 				"res_holder=1\nres_type=%02x\n"
1841 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1842 				"mapped_lun=%u\n", reg_count,
1843 				tpg->se_tpg_tfo->get_fabric_name(),
1844 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1845 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1846 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1847 				pr_reg->pr_res_mapped_lun);
1848 		} else {
1849 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1850 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1851 				"sa_res_key=%llu\nres_holder=0\n"
1852 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1853 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1854 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1855 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1856 				pr_reg->pr_res_mapped_lun);
1857 		}
1858 
1859 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1860 			pr_err("Unable to update renaming"
1861 				" APTPL metadata\n");
1862 			ret = -EMSGSIZE;
1863 			goto out;
1864 		}
1865 		len += sprintf(buf+len, "%s", tmp);
1866 
1867 		/*
1868 		 * Include information about the associated SCSI target port.
1869 		 */
1870 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1871 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1872 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1873 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1874 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1875 			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);
1876 
1877 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1878 			pr_err("Unable to update renaming"
1879 				" APTPL metadata\n");
1880 			ret = -EMSGSIZE;
1881 			goto out;
1882 		}
1883 		len += sprintf(buf+len, "%s", tmp);
1884 		reg_count++;
1885 	}
1886 
1887 	if (!reg_count)
1888 		len += sprintf(buf+len, "No Registrations or Reservations");
1889 
1890 out:
1891 	spin_unlock(&dev->t10_pr.registration_lock);
1892 	spin_unlock(&dev->dev_reservation_lock);
1893 
1894 	return ret;
1895 }
1896 
1897 static int __core_scsi3_write_aptpl_to_file(
1898 	struct se_device *dev,
1899 	unsigned char *buf)
1900 {
1901 	struct t10_wwn *wwn = &dev->t10_wwn;
1902 	struct file *file;
1903 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1904 	char path[512];
1905 	u32 pr_aptpl_buf_len;
1906 	int ret;
1907 
1908 	memset(path, 0, 512);
1909 
1910 	if (strlen(&wwn->unit_serial[0]) >= 512) {
1911 		pr_err("WWN value for struct se_device does not fit"
1912 			" into path buffer\n");
1913 		return -EMSGSIZE;
1914 	}
1915 
1916 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
1917 	file = filp_open(path, flags, 0600);
1918 	if (IS_ERR(file)) {
1919 		pr_err("filp_open(%s) for APTPL metadata"
1920 			" failed\n", path);
1921 		return PTR_ERR(file);
1922 	}
1923 
1924 	pr_aptpl_buf_len = (strlen(buf) + 1); /* Add extra for NULL */
1925 
1926 	ret = kernel_write(file, buf, pr_aptpl_buf_len, 0);
1927 
1928 	if (ret < 0)
1929 		pr_debug("Error writing APTPL metadata file: %s\n", path);
1930 	fput(file);
1931 
1932 	return (ret < 0) ? -EIO : 0;
1933 }
1934 
1935 /*
1936  * Clear the APTPL metadata if APTPL has been disabled, otherwise
1937  * write out the updated metadata to struct file for this SCSI device.
1938  */
1939 static sense_reason_t core_scsi3_update_and_write_aptpl(struct se_device *dev, bool aptpl)
1940 {
1941 	unsigned char *buf;
1942 	int rc;
1943 
1944 	if (!aptpl) {
1945 		char *null_buf = "No Registrations or Reservations\n";
1946 
1947 		rc = __core_scsi3_write_aptpl_to_file(dev, null_buf);
1948 		dev->t10_pr.pr_aptpl_active = 0;
1949 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated\n");
1950 
1951 		if (rc)
1952 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1953 
1954 		return 0;
1955 	}
1956 
1957 	buf = kzalloc(PR_APTPL_BUF_LEN, GFP_KERNEL);
1958 	if (!buf)
1959 		return TCM_OUT_OF_RESOURCES;
1960 
1961 	rc = core_scsi3_update_aptpl_buf(dev, buf, PR_APTPL_BUF_LEN);
1962 	if (rc < 0) {
1963 		kfree(buf);
1964 		return TCM_OUT_OF_RESOURCES;
1965 	}
1966 
1967 	rc = __core_scsi3_write_aptpl_to_file(dev, buf);
1968 	if (rc != 0) {
1969 		pr_err("SPC-3 PR: Could not update APTPL\n");
1970 		kfree(buf);
1971 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1972 	}
1973 	dev->t10_pr.pr_aptpl_active = 1;
1974 	kfree(buf);
1975 	pr_debug("SPC-3 PR: Set APTPL Bit Activated\n");
1976 	return 0;
1977 }
1978 
1979 static sense_reason_t
1980 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
1981 		bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type)
1982 {
1983 	struct se_session *se_sess = cmd->se_sess;
1984 	struct se_device *dev = cmd->se_dev;
1985 	struct se_dev_entry *se_deve;
1986 	struct se_lun *se_lun = cmd->se_lun;
1987 	struct se_portal_group *se_tpg;
1988 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp;
1989 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1990 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1991 	sense_reason_t ret = TCM_NO_SENSE;
1992 	int pr_holder = 0, type;
1993 
1994 	if (!se_sess || !se_lun) {
1995 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
1996 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1997 	}
1998 	se_tpg = se_sess->se_tpg;
1999 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2000 
2001 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2002 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2003 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2004 				PR_REG_ISID_LEN);
2005 		isid_ptr = &isid_buf[0];
2006 	}
2007 	/*
2008 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2009 	 */
2010 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2011 	if (!pr_reg) {
2012 		if (res_key) {
2013 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2014 				" for SA REGISTER, returning CONFLICT\n");
2015 			return TCM_RESERVATION_CONFLICT;
2016 		}
2017 		/*
2018 		 * Do nothing but return GOOD status.
2019 		 */
2020 		if (!sa_res_key)
2021 			return 0;
2022 
2023 		if (!spec_i_pt) {
2024 			/*
2025 			 * Perform the Service Action REGISTER on the Initiator
2026 			 * Port Endpoint that the PRO was received from on the
2027 			 * Logical Unit of the SCSI device server.
2028 			 */
2029 			if (core_scsi3_alloc_registration(cmd->se_dev,
2030 					se_sess->se_node_acl, se_deve, isid_ptr,
2031 					sa_res_key, all_tg_pt, aptpl,
2032 					register_type, 0)) {
2033 				pr_err("Unable to allocate"
2034 					" struct t10_pr_registration\n");
2035 				return TCM_INVALID_PARAMETER_LIST;
2036 			}
2037 		} else {
2038 			/*
2039 			 * Register both the Initiator port that received
2040 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2041 			 * TransportID from Parameter list and loop through
2042 			 * fabric dependent parameter list while calling
2043 			 * logic from of core_scsi3_alloc_registration() for
2044 			 * each TransportID provided SCSI Initiator Port/Device
2045 			 */
2046 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2047 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2048 			if (ret != 0)
2049 				return ret;
2050 		}
2051 
2052 		return core_scsi3_update_and_write_aptpl(dev, aptpl);
2053 	}
2054 
2055 	/* ok, existing registration */
2056 
2057 	if ((register_type == REGISTER) && (res_key != pr_reg->pr_res_key)) {
2058 		pr_err("SPC-3 PR REGISTER: Received"
2059 		       " res_key: 0x%016Lx does not match"
2060 		       " existing SA REGISTER res_key:"
2061 		       " 0x%016Lx\n", res_key,
2062 		       pr_reg->pr_res_key);
2063 		ret = TCM_RESERVATION_CONFLICT;
2064 		goto out;
2065 	}
2066 
2067 	if (spec_i_pt) {
2068 		pr_err("SPC-3 PR REGISTER: SPEC_I_PT"
2069 			" set on a registered nexus\n");
2070 		ret = TCM_INVALID_PARAMETER_LIST;
2071 		goto out;
2072 	}
2073 
2074 	/*
2075 	 * An existing ALL_TG_PT=1 registration being released
2076 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2077 	 */
2078 	if (pr_reg->pr_reg_all_tg_pt && !all_tg_pt) {
2079 		pr_err("SPC-3 PR REGISTER: ALL_TG_PT=1"
2080 			" registration exists, but ALL_TG_PT=1 bit not"
2081 			" present in received PROUT\n");
2082 		ret = TCM_INVALID_CDB_FIELD;
2083 		goto out;
2084 	}
2085 
2086 	/*
2087 	 * sa_res_key=1 Change Reservation Key for registered I_T Nexus.
2088 	 */
2089 	if (sa_res_key) {
2090 		/*
2091 		 * Increment PRgeneration counter for struct se_device"
2092 		 * upon a successful REGISTER, see spc4r17 section 6.3.2
2093 		 * READ_KEYS service action.
2094 		 */
2095 		pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2096 		pr_reg->pr_res_key = sa_res_key;
2097 		pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2098 			 " Key for %s to: 0x%016Lx PRgeneration:"
2099 			 " 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2100 			 (register_type == REGISTER_AND_IGNORE_EXISTING_KEY) ? "_AND_IGNORE_EXISTING_KEY" : "",
2101 			 pr_reg->pr_reg_nacl->initiatorname,
2102 			 pr_reg->pr_res_key, pr_reg->pr_res_generation);
2103 
2104 	} else {
2105 		/*
2106 		 * sa_res_key=0 Unregister Reservation Key for registered I_T Nexus.
2107 		 */
2108 		pr_holder = core_scsi3_check_implicit_release(
2109 				cmd->se_dev, pr_reg);
2110 		if (pr_holder < 0) {
2111 			ret = TCM_RESERVATION_CONFLICT;
2112 			goto out;
2113 		}
2114 		type = pr_reg->pr_res_type;
2115 
2116 		spin_lock(&pr_tmpl->registration_lock);
2117 		/*
2118 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2119 		 * and matching pr_res_key.
2120 		 */
2121 		if (pr_reg->pr_reg_all_tg_pt) {
2122 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2123 					&pr_tmpl->registration_list,
2124 					pr_reg_list) {
2125 
2126 				if (!pr_reg_p->pr_reg_all_tg_pt)
2127 					continue;
2128 				if (pr_reg_p->pr_res_key != res_key)
2129 					continue;
2130 				if (pr_reg == pr_reg_p)
2131 					continue;
2132 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2133 					   pr_reg_p->pr_reg_nacl->initiatorname))
2134 					continue;
2135 
2136 				__core_scsi3_free_registration(dev,
2137 						pr_reg_p, NULL, 0);
2138 			}
2139 		}
2140 
2141 		/*
2142 		 * Release the calling I_T Nexus registration now..
2143 		 */
2144 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2145 		pr_reg = NULL;
2146 
2147 		/*
2148 		 * From spc4r17, section 5.7.11.3 Unregistering
2149 		 *
2150 		 * If the persistent reservation is a registrants only
2151 		 * type, the device server shall establish a unit
2152 		 * attention condition for the initiator port associated
2153 		 * with every registered I_T nexus except for the I_T
2154 		 * nexus on which the PERSISTENT RESERVE OUT command was
2155 		 * received, with the additional sense code set to
2156 		 * RESERVATIONS RELEASED.
2157 		 */
2158 		if (pr_holder &&
2159 		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2160 		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2161 			list_for_each_entry(pr_reg_p,
2162 					&pr_tmpl->registration_list,
2163 					pr_reg_list) {
2164 
2165 				core_scsi3_ua_allocate(
2166 					pr_reg_p->pr_reg_nacl,
2167 					pr_reg_p->pr_res_mapped_lun,
2168 					0x2A,
2169 					ASCQ_2AH_RESERVATIONS_RELEASED);
2170 			}
2171 		}
2172 
2173 		spin_unlock(&pr_tmpl->registration_lock);
2174 	}
2175 
2176 	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
2177 
2178 out:
2179 	if (pr_reg)
2180 		core_scsi3_put_pr_reg(pr_reg);
2181 	return ret;
2182 }
2183 
2184 unsigned char *core_scsi3_pr_dump_type(int type)
2185 {
2186 	switch (type) {
2187 	case PR_TYPE_WRITE_EXCLUSIVE:
2188 		return "Write Exclusive Access";
2189 	case PR_TYPE_EXCLUSIVE_ACCESS:
2190 		return "Exclusive Access";
2191 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2192 		return "Write Exclusive Access, Registrants Only";
2193 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2194 		return "Exclusive Access, Registrants Only";
2195 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2196 		return "Write Exclusive Access, All Registrants";
2197 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2198 		return "Exclusive Access, All Registrants";
2199 	default:
2200 		break;
2201 	}
2202 
2203 	return "Unknown SPC-3 PR Type";
2204 }
2205 
2206 static sense_reason_t
2207 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2208 {
2209 	struct se_device *dev = cmd->se_dev;
2210 	struct se_session *se_sess = cmd->se_sess;
2211 	struct se_lun *se_lun = cmd->se_lun;
2212 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2213 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2214 	char i_buf[PR_REG_ISID_ID_LEN];
2215 	sense_reason_t ret;
2216 
2217 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2218 
2219 	if (!se_sess || !se_lun) {
2220 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2221 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2222 	}
2223 	/*
2224 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2225 	 */
2226 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2227 				se_sess);
2228 	if (!pr_reg) {
2229 		pr_err("SPC-3 PR: Unable to locate"
2230 			" PR_REGISTERED *pr_reg for RESERVE\n");
2231 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2232 	}
2233 	/*
2234 	 * From spc4r17 Section 5.7.9: Reserving:
2235 	 *
2236 	 * An application client creates a persistent reservation by issuing
2237 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2238 	 * a registered I_T nexus with the following parameters:
2239 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2240 	 * 	 registered with the logical unit for the I_T nexus; and
2241 	 */
2242 	if (res_key != pr_reg->pr_res_key) {
2243 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2244 			" does not match existing SA REGISTER res_key:"
2245 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2246 		ret = TCM_RESERVATION_CONFLICT;
2247 		goto out_put_pr_reg;
2248 	}
2249 	/*
2250 	 * From spc4r17 Section 5.7.9: Reserving:
2251 	 *
2252 	 * From above:
2253 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2254 	 *     being created.
2255 	 *
2256 	 * Only one persistent reservation is allowed at a time per logical unit
2257 	 * and that persistent reservation has a scope of LU_SCOPE.
2258 	 */
2259 	if (scope != PR_SCOPE_LU_SCOPE) {
2260 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2261 		ret = TCM_INVALID_PARAMETER_LIST;
2262 		goto out_put_pr_reg;
2263 	}
2264 	/*
2265 	 * See if we have an existing PR reservation holder pointer at
2266 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2267 	 * *pr_res_holder.
2268 	 */
2269 	spin_lock(&dev->dev_reservation_lock);
2270 	pr_res_holder = dev->dev_pr_res_holder;
2271 	if (pr_res_holder) {
2272 		/*
2273 		 * From spc4r17 Section 5.7.9: Reserving:
2274 		 *
2275 		 * If the device server receives a PERSISTENT RESERVE OUT
2276 		 * command from an I_T nexus other than a persistent reservation
2277 		 * holder (see 5.7.10) that attempts to create a persistent
2278 		 * reservation when a persistent reservation already exists for
2279 		 * the logical unit, then the command shall be completed with
2280 		 * RESERVATION CONFLICT status.
2281 		 */
2282 		if (pr_res_holder != pr_reg) {
2283 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2284 			pr_err("SPC-3 PR: Attempted RESERVE from"
2285 				" [%s]: %s while reservation already held by"
2286 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2287 				cmd->se_tfo->get_fabric_name(),
2288 				se_sess->se_node_acl->initiatorname,
2289 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2290 				pr_res_holder->pr_reg_nacl->initiatorname);
2291 
2292 			spin_unlock(&dev->dev_reservation_lock);
2293 			ret = TCM_RESERVATION_CONFLICT;
2294 			goto out_put_pr_reg;
2295 		}
2296 		/*
2297 		 * From spc4r17 Section 5.7.9: Reserving:
2298 		 *
2299 		 * If a persistent reservation holder attempts to modify the
2300 		 * type or scope of an existing persistent reservation, the
2301 		 * command shall be completed with RESERVATION CONFLICT status.
2302 		 */
2303 		if ((pr_res_holder->pr_res_type != type) ||
2304 		    (pr_res_holder->pr_res_scope != scope)) {
2305 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2306 			pr_err("SPC-3 PR: Attempted RESERVE from"
2307 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2308 				" while reservation already held by [%s]: %s,"
2309 				" returning RESERVATION_CONFLICT\n",
2310 				cmd->se_tfo->get_fabric_name(),
2311 				se_sess->se_node_acl->initiatorname,
2312 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2313 				pr_res_holder->pr_reg_nacl->initiatorname);
2314 
2315 			spin_unlock(&dev->dev_reservation_lock);
2316 			ret = TCM_RESERVATION_CONFLICT;
2317 			goto out_put_pr_reg;
2318 		}
2319 		/*
2320 		 * From spc4r17 Section 5.7.9: Reserving:
2321 		 *
2322 		 * If the device server receives a PERSISTENT RESERVE OUT
2323 		 * command with RESERVE service action where the TYPE field and
2324 		 * the SCOPE field contain the same values as the existing type
2325 		 * and scope from a persistent reservation holder, it shall not
2326 		 * make any change to the existing persistent reservation and
2327 		 * shall completethe command with GOOD status.
2328 		 */
2329 		spin_unlock(&dev->dev_reservation_lock);
2330 		ret = 0;
2331 		goto out_put_pr_reg;
2332 	}
2333 	/*
2334 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2335 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2336 	 */
2337 	pr_reg->pr_res_scope = scope;
2338 	pr_reg->pr_res_type = type;
2339 	pr_reg->pr_res_holder = 1;
2340 	dev->dev_pr_res_holder = pr_reg;
2341 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2342 
2343 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2344 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2345 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2346 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2347 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2348 			cmd->se_tfo->get_fabric_name(),
2349 			se_sess->se_node_acl->initiatorname,
2350 			i_buf);
2351 	spin_unlock(&dev->dev_reservation_lock);
2352 
2353 	if (pr_tmpl->pr_aptpl_active)
2354 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2355 
2356 	ret = 0;
2357 out_put_pr_reg:
2358 	core_scsi3_put_pr_reg(pr_reg);
2359 	return ret;
2360 }
2361 
2362 static sense_reason_t
2363 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2364 		u64 res_key)
2365 {
2366 	switch (type) {
2367 	case PR_TYPE_WRITE_EXCLUSIVE:
2368 	case PR_TYPE_EXCLUSIVE_ACCESS:
2369 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2370 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2371 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2372 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2373 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2374 	default:
2375 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2376 			" 0x%02x\n", type);
2377 		return TCM_INVALID_CDB_FIELD;
2378 	}
2379 }
2380 
2381 /*
2382  * Called with struct se_device->dev_reservation_lock held.
2383  */
2384 static void __core_scsi3_complete_pro_release(
2385 	struct se_device *dev,
2386 	struct se_node_acl *se_nacl,
2387 	struct t10_pr_registration *pr_reg,
2388 	int explicit)
2389 {
2390 	struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2391 	char i_buf[PR_REG_ISID_ID_LEN];
2392 
2393 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2394 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2395 	/*
2396 	 * Go ahead and release the current PR reservation holder.
2397 	 */
2398 	dev->dev_pr_res_holder = NULL;
2399 
2400 	pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2401 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2402 		tfo->get_fabric_name(), (explicit) ? "explicit" : "implicit",
2403 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
2404 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2405 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2406 		tfo->get_fabric_name(), se_nacl->initiatorname,
2407 		i_buf);
2408 	/*
2409 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2410 	 */
2411 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2412 }
2413 
2414 static sense_reason_t
2415 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2416 		u64 res_key)
2417 {
2418 	struct se_device *dev = cmd->se_dev;
2419 	struct se_session *se_sess = cmd->se_sess;
2420 	struct se_lun *se_lun = cmd->se_lun;
2421 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2422 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2423 	int all_reg = 0;
2424 	sense_reason_t ret = 0;
2425 
2426 	if (!se_sess || !se_lun) {
2427 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2428 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2429 	}
2430 	/*
2431 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2432 	 */
2433 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2434 	if (!pr_reg) {
2435 		pr_err("SPC-3 PR: Unable to locate"
2436 			" PR_REGISTERED *pr_reg for RELEASE\n");
2437 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2438 	}
2439 	/*
2440 	 * From spc4r17 Section 5.7.11.2 Releasing:
2441 	 *
2442 	 * If there is no persistent reservation or in response to a persistent
2443 	 * reservation release request from a registered I_T nexus that is not a
2444 	 * persistent reservation holder (see 5.7.10), the device server shall
2445 	 * do the following:
2446 	 *
2447 	 *     a) Not release the persistent reservation, if any;
2448 	 *     b) Not remove any registrations; and
2449 	 *     c) Complete the command with GOOD status.
2450 	 */
2451 	spin_lock(&dev->dev_reservation_lock);
2452 	pr_res_holder = dev->dev_pr_res_holder;
2453 	if (!pr_res_holder) {
2454 		/*
2455 		 * No persistent reservation, return GOOD status.
2456 		 */
2457 		spin_unlock(&dev->dev_reservation_lock);
2458 		goto out_put_pr_reg;
2459 	}
2460 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2461 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
2462 		all_reg = 1;
2463 
2464 	if ((all_reg == 0) && (pr_res_holder != pr_reg)) {
2465 		/*
2466 		 * Non 'All Registrants' PR Type cases..
2467 		 * Release request from a registered I_T nexus that is not a
2468 		 * persistent reservation holder. return GOOD status.
2469 		 */
2470 		spin_unlock(&dev->dev_reservation_lock);
2471 		goto out_put_pr_reg;
2472 	}
2473 
2474 	/*
2475 	 * From spc4r17 Section 5.7.11.2 Releasing:
2476 	 *
2477 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2478 	 * release a persistent reservation.
2479 	 *
2480 	 * An application client releases the persistent reservation by issuing
2481 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2482 	 * an I_T nexus that is a persistent reservation holder with the
2483 	 * following parameters:
2484 	 *
2485 	 *     a) RESERVATION KEY field set to the value of the reservation key
2486 	 *	  that is registered with the logical unit for the I_T nexus;
2487 	 */
2488 	if (res_key != pr_reg->pr_res_key) {
2489 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2490 			" does not match existing SA REGISTER res_key:"
2491 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2492 		spin_unlock(&dev->dev_reservation_lock);
2493 		ret = TCM_RESERVATION_CONFLICT;
2494 		goto out_put_pr_reg;
2495 	}
2496 	/*
2497 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2498 	 *
2499 	 * b) TYPE field and SCOPE field set to match the persistent
2500 	 *    reservation being released.
2501 	 */
2502 	if ((pr_res_holder->pr_res_type != type) ||
2503 	    (pr_res_holder->pr_res_scope != scope)) {
2504 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2505 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2506 			" reservation from [%s]: %s with different TYPE "
2507 			"and/or SCOPE  while reservation already held by"
2508 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2509 			cmd->se_tfo->get_fabric_name(),
2510 			se_sess->se_node_acl->initiatorname,
2511 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2512 			pr_res_holder->pr_reg_nacl->initiatorname);
2513 
2514 		spin_unlock(&dev->dev_reservation_lock);
2515 		ret = TCM_RESERVATION_CONFLICT;
2516 		goto out_put_pr_reg;
2517 	}
2518 	/*
2519 	 * In response to a persistent reservation release request from the
2520 	 * persistent reservation holder the device server shall perform a
2521 	 * release by doing the following as an uninterrupted series of actions:
2522 	 * a) Release the persistent reservation;
2523 	 * b) Not remove any registration(s);
2524 	 * c) If the released persistent reservation is a registrants only type
2525 	 * or all registrants type persistent reservation,
2526 	 *    the device server shall establish a unit attention condition for
2527 	 *    the initiator port associated with every regis-
2528 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2529 	 *    RESERVE OUT command with RELEASE service action was received,
2530 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2531 	 * d) If the persistent reservation is of any other type, the device
2532 	 *    server shall not establish a unit attention condition.
2533 	 */
2534 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2535 			pr_reg, 1);
2536 
2537 	spin_unlock(&dev->dev_reservation_lock);
2538 
2539 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2540 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2541 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2542 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2543 		/*
2544 		 * If no UNIT ATTENTION conditions will be established for
2545 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2546 		 * go ahead and check for APTPL=1 update+write below
2547 		 */
2548 		goto write_aptpl;
2549 	}
2550 
2551 	spin_lock(&pr_tmpl->registration_lock);
2552 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2553 			pr_reg_list) {
2554 		/*
2555 		 * Do not establish a UNIT ATTENTION condition
2556 		 * for the calling I_T Nexus
2557 		 */
2558 		if (pr_reg_p == pr_reg)
2559 			continue;
2560 
2561 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2562 				pr_reg_p->pr_res_mapped_lun,
2563 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2564 	}
2565 	spin_unlock(&pr_tmpl->registration_lock);
2566 
2567 write_aptpl:
2568 	if (pr_tmpl->pr_aptpl_active)
2569 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2570 
2571 out_put_pr_reg:
2572 	core_scsi3_put_pr_reg(pr_reg);
2573 	return ret;
2574 }
2575 
2576 static sense_reason_t
2577 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2578 {
2579 	struct se_device *dev = cmd->se_dev;
2580 	struct se_node_acl *pr_reg_nacl;
2581 	struct se_session *se_sess = cmd->se_sess;
2582 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2583 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2584 	u32 pr_res_mapped_lun = 0;
2585 	int calling_it_nexus = 0;
2586 	/*
2587 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2588 	 */
2589 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2590 			se_sess->se_node_acl, se_sess);
2591 	if (!pr_reg_n) {
2592 		pr_err("SPC-3 PR: Unable to locate"
2593 			" PR_REGISTERED *pr_reg for CLEAR\n");
2594 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2595 	}
2596 	/*
2597 	 * From spc4r17 section 5.7.11.6, Clearing:
2598 	 *
2599 	 * Any application client may release the persistent reservation and
2600 	 * remove all registrations from a device server by issuing a
2601 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2602 	 * registered I_T nexus with the following parameter:
2603 	 *
2604 	 *	a) RESERVATION KEY field set to the value of the reservation key
2605 	 * 	   that is registered with the logical unit for the I_T nexus.
2606 	 */
2607 	if (res_key != pr_reg_n->pr_res_key) {
2608 		pr_err("SPC-3 PR REGISTER: Received"
2609 			" res_key: 0x%016Lx does not match"
2610 			" existing SA REGISTER res_key:"
2611 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2612 		core_scsi3_put_pr_reg(pr_reg_n);
2613 		return TCM_RESERVATION_CONFLICT;
2614 	}
2615 	/*
2616 	 * a) Release the persistent reservation, if any;
2617 	 */
2618 	spin_lock(&dev->dev_reservation_lock);
2619 	pr_res_holder = dev->dev_pr_res_holder;
2620 	if (pr_res_holder) {
2621 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2622 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2623 			pr_res_holder, 0);
2624 	}
2625 	spin_unlock(&dev->dev_reservation_lock);
2626 	/*
2627 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2628 	 */
2629 	spin_lock(&pr_tmpl->registration_lock);
2630 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2631 			&pr_tmpl->registration_list, pr_reg_list) {
2632 
2633 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2634 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2635 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2636 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2637 					calling_it_nexus);
2638 		/*
2639 		 * e) Establish a unit attention condition for the initiator
2640 		 *    port associated with every registered I_T nexus other
2641 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2642 		 *    command with CLEAR service action was received, with the
2643 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2644 		 */
2645 		if (!calling_it_nexus)
2646 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2647 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2648 	}
2649 	spin_unlock(&pr_tmpl->registration_lock);
2650 
2651 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2652 		cmd->se_tfo->get_fabric_name());
2653 
2654 	core_scsi3_update_and_write_aptpl(cmd->se_dev, false);
2655 
2656 	core_scsi3_pr_generation(dev);
2657 	return 0;
2658 }
2659 
2660 /*
2661  * Called with struct se_device->dev_reservation_lock held.
2662  */
2663 static void __core_scsi3_complete_pro_preempt(
2664 	struct se_device *dev,
2665 	struct t10_pr_registration *pr_reg,
2666 	struct list_head *preempt_and_abort_list,
2667 	int type,
2668 	int scope,
2669 	enum preempt_type preempt_type)
2670 {
2671 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2672 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2673 	char i_buf[PR_REG_ISID_ID_LEN];
2674 
2675 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2676 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
2677 	/*
2678 	 * Do an implicit RELEASE of the existing reservation.
2679 	 */
2680 	if (dev->dev_pr_res_holder)
2681 		__core_scsi3_complete_pro_release(dev, nacl,
2682 				dev->dev_pr_res_holder, 0);
2683 
2684 	dev->dev_pr_res_holder = pr_reg;
2685 	pr_reg->pr_res_holder = 1;
2686 	pr_reg->pr_res_type = type;
2687 	pr_reg->pr_res_scope = scope;
2688 
2689 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2690 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2691 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2692 		core_scsi3_pr_dump_type(type),
2693 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2694 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2695 		tfo->get_fabric_name(), (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "",
2696 		nacl->initiatorname, i_buf);
2697 	/*
2698 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2699 	 * struct t10_pr_registration to the list that will be compared
2700 	 * against received CDBs..
2701 	 */
2702 	if (preempt_and_abort_list)
2703 		list_add_tail(&pr_reg->pr_reg_abort_list,
2704 				preempt_and_abort_list);
2705 }
2706 
2707 static void core_scsi3_release_preempt_and_abort(
2708 	struct list_head *preempt_and_abort_list,
2709 	struct t10_pr_registration *pr_reg_holder)
2710 {
2711 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2712 
2713 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2714 				pr_reg_abort_list) {
2715 
2716 		list_del(&pr_reg->pr_reg_abort_list);
2717 		if (pr_reg_holder == pr_reg)
2718 			continue;
2719 		if (pr_reg->pr_res_holder) {
2720 			pr_warn("pr_reg->pr_res_holder still set\n");
2721 			continue;
2722 		}
2723 
2724 		pr_reg->pr_reg_deve = NULL;
2725 		pr_reg->pr_reg_nacl = NULL;
2726 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2727 	}
2728 }
2729 
2730 static sense_reason_t
2731 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2732 		u64 sa_res_key, enum preempt_type preempt_type)
2733 {
2734 	struct se_device *dev = cmd->se_dev;
2735 	struct se_node_acl *pr_reg_nacl;
2736 	struct se_session *se_sess = cmd->se_sess;
2737 	LIST_HEAD(preempt_and_abort_list);
2738 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2739 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2740 	u32 pr_res_mapped_lun = 0;
2741 	int all_reg = 0, calling_it_nexus = 0, released_regs = 0;
2742 	int prh_type = 0, prh_scope = 0;
2743 
2744 	if (!se_sess)
2745 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2746 
2747 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2748 				se_sess);
2749 	if (!pr_reg_n) {
2750 		pr_err("SPC-3 PR: Unable to locate"
2751 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2752 			(preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "");
2753 		return TCM_RESERVATION_CONFLICT;
2754 	}
2755 	if (pr_reg_n->pr_res_key != res_key) {
2756 		core_scsi3_put_pr_reg(pr_reg_n);
2757 		return TCM_RESERVATION_CONFLICT;
2758 	}
2759 	if (scope != PR_SCOPE_LU_SCOPE) {
2760 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2761 		core_scsi3_put_pr_reg(pr_reg_n);
2762 		return TCM_INVALID_PARAMETER_LIST;
2763 	}
2764 
2765 	spin_lock(&dev->dev_reservation_lock);
2766 	pr_res_holder = dev->dev_pr_res_holder;
2767 	if (pr_res_holder &&
2768 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2769 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2770 		all_reg = 1;
2771 
2772 	if (!all_reg && !sa_res_key) {
2773 		spin_unlock(&dev->dev_reservation_lock);
2774 		core_scsi3_put_pr_reg(pr_reg_n);
2775 		return TCM_INVALID_PARAMETER_LIST;
2776 	}
2777 	/*
2778 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2779 	 *
2780 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2781 	 * persistent reservation holder or there is no persistent reservation
2782 	 * holder (i.e., there is no persistent reservation), then the device
2783 	 * server shall perform a preempt by doing the following in an
2784 	 * uninterrupted series of actions. (See below..)
2785 	 */
2786 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2787 		/*
2788 		 * No existing or SA Reservation Key matching reservations..
2789 		 *
2790 		 * PROUT SA PREEMPT with All Registrant type reservations are
2791 		 * allowed to be processed without a matching SA Reservation Key
2792 		 */
2793 		spin_lock(&pr_tmpl->registration_lock);
2794 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2795 				&pr_tmpl->registration_list, pr_reg_list) {
2796 			/*
2797 			 * Removing of registrations in non all registrants
2798 			 * type reservations without a matching SA reservation
2799 			 * key.
2800 			 *
2801 			 * a) Remove the registrations for all I_T nexuses
2802 			 *    specified by the SERVICE ACTION RESERVATION KEY
2803 			 *    field;
2804 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2805 			 * c) Process tasks as defined in 5.7.1; and
2806 			 * d) Establish a unit attention condition for the
2807 			 *    initiator port associated with every I_T nexus
2808 			 *    that lost its registration other than the I_T
2809 			 *    nexus on which the PERSISTENT RESERVE OUT command
2810 			 *    was received, with the additional sense code set
2811 			 *    to REGISTRATIONS PREEMPTED.
2812 			 */
2813 			if (!all_reg) {
2814 				if (pr_reg->pr_res_key != sa_res_key)
2815 					continue;
2816 
2817 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2818 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2819 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2820 				__core_scsi3_free_registration(dev, pr_reg,
2821 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2822 						NULL, calling_it_nexus);
2823 				released_regs++;
2824 			} else {
2825 				/*
2826 				 * Case for any existing all registrants type
2827 				 * reservation, follow logic in spc4r17 section
2828 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2829 				 *
2830 				 * For a ZERO SA Reservation key, release
2831 				 * all other registrations and do an implicit
2832 				 * release of active persistent reservation.
2833 				 *
2834 				 * For a non-ZERO SA Reservation key, only
2835 				 * release the matching reservation key from
2836 				 * registrations.
2837 				 */
2838 				if ((sa_res_key) &&
2839 				     (pr_reg->pr_res_key != sa_res_key))
2840 					continue;
2841 
2842 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2843 				if (calling_it_nexus)
2844 					continue;
2845 
2846 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2847 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2848 				__core_scsi3_free_registration(dev, pr_reg,
2849 					(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list :
2850 						NULL, 0);
2851 				released_regs++;
2852 			}
2853 			if (!calling_it_nexus)
2854 				core_scsi3_ua_allocate(pr_reg_nacl,
2855 					pr_res_mapped_lun, 0x2A,
2856 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2857 		}
2858 		spin_unlock(&pr_tmpl->registration_lock);
2859 		/*
2860 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
2861 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
2862 		 * RESERVATION KEY field to a value that does not match any
2863 		 * registered reservation key, then the device server shall
2864 		 * complete the command with RESERVATION CONFLICT status.
2865 		 */
2866 		if (!released_regs) {
2867 			spin_unlock(&dev->dev_reservation_lock);
2868 			core_scsi3_put_pr_reg(pr_reg_n);
2869 			return TCM_RESERVATION_CONFLICT;
2870 		}
2871 		/*
2872 		 * For an existing all registrants type reservation
2873 		 * with a zero SA rservation key, preempt the existing
2874 		 * reservation with the new PR type and scope.
2875 		 */
2876 		if (pr_res_holder && all_reg && !(sa_res_key)) {
2877 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2878 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2879 				type, scope, preempt_type);
2880 
2881 			if (preempt_type == PREEMPT_AND_ABORT)
2882 				core_scsi3_release_preempt_and_abort(
2883 					&preempt_and_abort_list, pr_reg_n);
2884 		}
2885 		spin_unlock(&dev->dev_reservation_lock);
2886 
2887 		if (pr_tmpl->pr_aptpl_active)
2888 			core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
2889 
2890 		core_scsi3_put_pr_reg(pr_reg_n);
2891 		core_scsi3_pr_generation(cmd->se_dev);
2892 		return 0;
2893 	}
2894 	/*
2895 	 * The PREEMPTing SA reservation key matches that of the
2896 	 * existing persistent reservation, first, we check if
2897 	 * we are preempting our own reservation.
2898 	 * From spc4r17, section 5.7.11.4.3 Preempting
2899 	 * persistent reservations and registration handling
2900 	 *
2901 	 * If an all registrants persistent reservation is not
2902 	 * present, it is not an error for the persistent
2903 	 * reservation holder to preempt itself (i.e., a
2904 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
2905 	 * or a PREEMPT AND ABORT service action with the
2906 	 * SERVICE ACTION RESERVATION KEY value equal to the
2907 	 * persistent reservation holder's reservation key that
2908 	 * is received from the persistent reservation holder).
2909 	 * In that case, the device server shall establish the
2910 	 * new persistent reservation and maintain the
2911 	 * registration.
2912 	 */
2913 	prh_type = pr_res_holder->pr_res_type;
2914 	prh_scope = pr_res_holder->pr_res_scope;
2915 	/*
2916 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
2917 	 * persistent reservation holder (see 5.7.10), the device
2918 	 * server shall perform a preempt by doing the following as
2919 	 * an uninterrupted series of actions:
2920 	 *
2921 	 * a) Release the persistent reservation for the holder
2922 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
2923 	 */
2924 	if (pr_reg_n != pr_res_holder)
2925 		__core_scsi3_complete_pro_release(dev,
2926 				pr_res_holder->pr_reg_nacl,
2927 				dev->dev_pr_res_holder, 0);
2928 	/*
2929 	 * b) Remove the registrations for all I_T nexuses identified
2930 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
2931 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
2932 	 *    OUT command. If an all registrants persistent reservation
2933 	 *    is present and the SERVICE ACTION RESERVATION KEY field
2934 	 *    is set to zero, then all registrations shall be removed
2935 	 *    except for that of the I_T nexus that is being used for
2936 	 *    the PERSISTENT RESERVE OUT command;
2937 	 */
2938 	spin_lock(&pr_tmpl->registration_lock);
2939 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2940 			&pr_tmpl->registration_list, pr_reg_list) {
2941 
2942 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2943 		if (calling_it_nexus)
2944 			continue;
2945 
2946 		if (pr_reg->pr_res_key != sa_res_key)
2947 			continue;
2948 
2949 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2950 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2951 		__core_scsi3_free_registration(dev, pr_reg,
2952 				(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2953 				calling_it_nexus);
2954 		/*
2955 		 * e) Establish a unit attention condition for the initiator
2956 		 *    port associated with every I_T nexus that lost its
2957 		 *    persistent reservation and/or registration, with the
2958 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
2959 		 */
2960 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
2961 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
2962 	}
2963 	spin_unlock(&pr_tmpl->registration_lock);
2964 	/*
2965 	 * c) Establish a persistent reservation for the preempting
2966 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
2967 	 */
2968 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
2969 			(preempt_type == PREEMPT_AND_ABORT) ? &preempt_and_abort_list : NULL,
2970 			type, scope, preempt_type);
2971 	/*
2972 	 * d) Process tasks as defined in 5.7.1;
2973 	 * e) See above..
2974 	 * f) If the type or scope has changed, then for every I_T nexus
2975 	 *    whose reservation key was not removed, except for the I_T
2976 	 *    nexus on which the PERSISTENT RESERVE OUT command was
2977 	 *    received, the device server shall establish a unit
2978 	 *    attention condition for the initiator port associated with
2979 	 *    that I_T nexus, with the additional sense code set to
2980 	 *    RESERVATIONS RELEASED. If the type or scope have not
2981 	 *    changed, then no unit attention condition(s) shall be
2982 	 *    established for this reason.
2983 	 */
2984 	if ((prh_type != type) || (prh_scope != scope)) {
2985 		spin_lock(&pr_tmpl->registration_lock);
2986 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2987 				&pr_tmpl->registration_list, pr_reg_list) {
2988 
2989 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2990 			if (calling_it_nexus)
2991 				continue;
2992 
2993 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
2994 					pr_reg->pr_res_mapped_lun, 0x2A,
2995 					ASCQ_2AH_RESERVATIONS_RELEASED);
2996 		}
2997 		spin_unlock(&pr_tmpl->registration_lock);
2998 	}
2999 	spin_unlock(&dev->dev_reservation_lock);
3000 	/*
3001 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3002 	 * All received CDBs for the matching existing reservation and
3003 	 * registrations undergo ABORT_TASK logic.
3004 	 *
3005 	 * From there, core_scsi3_release_preempt_and_abort() will
3006 	 * release every registration in the list (which have already
3007 	 * been removed from the primary pr_reg list), except the
3008 	 * new persistent reservation holder, the calling Initiator Port.
3009 	 */
3010 	if (preempt_type == PREEMPT_AND_ABORT) {
3011 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3012 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3013 						pr_reg_n);
3014 	}
3015 
3016 	if (pr_tmpl->pr_aptpl_active)
3017 		core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
3018 
3019 	core_scsi3_put_pr_reg(pr_reg_n);
3020 	core_scsi3_pr_generation(cmd->se_dev);
3021 	return 0;
3022 }
3023 
3024 static sense_reason_t
3025 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3026 		u64 res_key, u64 sa_res_key, enum preempt_type preempt_type)
3027 {
3028 	switch (type) {
3029 	case PR_TYPE_WRITE_EXCLUSIVE:
3030 	case PR_TYPE_EXCLUSIVE_ACCESS:
3031 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3032 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3033 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3034 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3035 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3036 					      sa_res_key, preempt_type);
3037 	default:
3038 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3039 			" Type: 0x%02x\n", (preempt_type == PREEMPT_AND_ABORT) ? "_AND_ABORT" : "", type);
3040 		return TCM_INVALID_CDB_FIELD;
3041 	}
3042 }
3043 
3044 
3045 static sense_reason_t
3046 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3047 		u64 sa_res_key, int aptpl, int unreg)
3048 {
3049 	struct se_session *se_sess = cmd->se_sess;
3050 	struct se_device *dev = cmd->se_dev;
3051 	struct se_dev_entry *dest_se_deve = NULL;
3052 	struct se_lun *se_lun = cmd->se_lun;
3053 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3054 	struct se_port *se_port;
3055 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3056 	struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3057 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3058 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3059 	unsigned char *buf;
3060 	unsigned char *initiator_str;
3061 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
3062 	u32 tid_len, tmp_tid_len;
3063 	int new_reg = 0, type, scope, matching_iname;
3064 	sense_reason_t ret;
3065 	unsigned short rtpi;
3066 	unsigned char proto_ident;
3067 
3068 	if (!se_sess || !se_lun) {
3069 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3070 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3071 	}
3072 
3073 	memset(dest_iport, 0, 64);
3074 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3075 	se_tpg = se_sess->se_tpg;
3076 	tf_ops = se_tpg->se_tpg_tfo;
3077 	/*
3078 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3079 	 *	Register behaviors for a REGISTER AND MOVE service action
3080 	 *
3081 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3082 	 */
3083 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3084 				se_sess);
3085 	if (!pr_reg) {
3086 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3087 			" *pr_reg for REGISTER_AND_MOVE\n");
3088 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3089 	}
3090 	/*
3091 	 * The provided reservation key much match the existing reservation key
3092 	 * provided during this initiator's I_T nexus registration.
3093 	 */
3094 	if (res_key != pr_reg->pr_res_key) {
3095 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3096 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3097 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3098 		ret = TCM_RESERVATION_CONFLICT;
3099 		goto out_put_pr_reg;
3100 	}
3101 	/*
3102 	 * The service active reservation key needs to be non zero
3103 	 */
3104 	if (!sa_res_key) {
3105 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3106 			" sa_res_key\n");
3107 		ret = TCM_INVALID_PARAMETER_LIST;
3108 		goto out_put_pr_reg;
3109 	}
3110 
3111 	/*
3112 	 * Determine the Relative Target Port Identifier where the reservation
3113 	 * will be moved to for the TransportID containing SCSI initiator WWN
3114 	 * information.
3115 	 */
3116 	buf = transport_kmap_data_sg(cmd);
3117 	if (!buf) {
3118 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3119 		goto out_put_pr_reg;
3120 	}
3121 
3122 	rtpi = (buf[18] & 0xff) << 8;
3123 	rtpi |= buf[19] & 0xff;
3124 	tid_len = (buf[20] & 0xff) << 24;
3125 	tid_len |= (buf[21] & 0xff) << 16;
3126 	tid_len |= (buf[22] & 0xff) << 8;
3127 	tid_len |= buf[23] & 0xff;
3128 	transport_kunmap_data_sg(cmd);
3129 	buf = NULL;
3130 
3131 	if ((tid_len + 24) != cmd->data_length) {
3132 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3133 			" does not equal CDB data_length: %u\n", tid_len,
3134 			cmd->data_length);
3135 		ret = TCM_INVALID_PARAMETER_LIST;
3136 		goto out_put_pr_reg;
3137 	}
3138 
3139 	spin_lock(&dev->se_port_lock);
3140 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3141 		if (se_port->sep_rtpi != rtpi)
3142 			continue;
3143 		dest_se_tpg = se_port->sep_tpg;
3144 		if (!dest_se_tpg)
3145 			continue;
3146 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3147 		if (!dest_tf_ops)
3148 			continue;
3149 
3150 		atomic_inc_mb(&dest_se_tpg->tpg_pr_ref_count);
3151 		spin_unlock(&dev->se_port_lock);
3152 
3153 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3154 			pr_err("core_scsi3_tpg_depend_item() failed"
3155 				" for dest_se_tpg\n");
3156 			atomic_dec_mb(&dest_se_tpg->tpg_pr_ref_count);
3157 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3158 			goto out_put_pr_reg;
3159 		}
3160 
3161 		spin_lock(&dev->se_port_lock);
3162 		break;
3163 	}
3164 	spin_unlock(&dev->se_port_lock);
3165 
3166 	if (!dest_se_tpg || !dest_tf_ops) {
3167 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3168 			" fabric ops from Relative Target Port Identifier:"
3169 			" %hu\n", rtpi);
3170 		ret = TCM_INVALID_PARAMETER_LIST;
3171 		goto out_put_pr_reg;
3172 	}
3173 
3174 	buf = transport_kmap_data_sg(cmd);
3175 	if (!buf) {
3176 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3177 		goto out_put_pr_reg;
3178 	}
3179 	proto_ident = (buf[24] & 0x0f);
3180 
3181 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3182 			" 0x%02x\n", proto_ident);
3183 
3184 	if (proto_ident != dest_tf_ops->get_fabric_proto_ident(dest_se_tpg)) {
3185 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3186 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3187 			" from fabric: %s\n", proto_ident,
3188 			dest_tf_ops->get_fabric_proto_ident(dest_se_tpg),
3189 			dest_tf_ops->get_fabric_name());
3190 		ret = TCM_INVALID_PARAMETER_LIST;
3191 		goto out;
3192 	}
3193 	if (dest_tf_ops->tpg_parse_pr_out_transport_id == NULL) {
3194 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Fabric does not"
3195 			" containg a valid tpg_parse_pr_out_transport_id"
3196 			" function pointer\n");
3197 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3198 		goto out;
3199 	}
3200 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(dest_se_tpg,
3201 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3202 	if (!initiator_str) {
3203 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3204 			" initiator_str from Transport ID\n");
3205 		ret = TCM_INVALID_PARAMETER_LIST;
3206 		goto out;
3207 	}
3208 
3209 	transport_kunmap_data_sg(cmd);
3210 	buf = NULL;
3211 
3212 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3213 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3214 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3215 		iport_ptr : "");
3216 	/*
3217 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3218 	 * action specifies a TransportID that is the same as the initiator port
3219 	 * of the I_T nexus for the command received, then the command shall
3220 	 * be terminated with CHECK CONDITION status, with the sense key set to
3221 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3222 	 * IN PARAMETER LIST.
3223 	 */
3224 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3225 	matching_iname = (!strcmp(initiator_str,
3226 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3227 	if (!matching_iname)
3228 		goto after_iport_check;
3229 
3230 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3231 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3232 			" matches: %s on received I_T Nexus\n", initiator_str,
3233 			pr_reg_nacl->initiatorname);
3234 		ret = TCM_INVALID_PARAMETER_LIST;
3235 		goto out;
3236 	}
3237 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3238 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3239 			" matches: %s %s on received I_T Nexus\n",
3240 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3241 			pr_reg->pr_reg_isid);
3242 		ret = TCM_INVALID_PARAMETER_LIST;
3243 		goto out;
3244 	}
3245 after_iport_check:
3246 	/*
3247 	 * Locate the destination struct se_node_acl from the received Transport ID
3248 	 */
3249 	spin_lock_irq(&dest_se_tpg->acl_node_lock);
3250 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3251 				initiator_str);
3252 	if (dest_node_acl)
3253 		atomic_inc_mb(&dest_node_acl->acl_pr_ref_count);
3254 	spin_unlock_irq(&dest_se_tpg->acl_node_lock);
3255 
3256 	if (!dest_node_acl) {
3257 		pr_err("Unable to locate %s dest_node_acl for"
3258 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3259 			initiator_str);
3260 		ret = TCM_INVALID_PARAMETER_LIST;
3261 		goto out;
3262 	}
3263 
3264 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3265 		pr_err("core_scsi3_nodeacl_depend_item() for"
3266 			" dest_node_acl\n");
3267 		atomic_dec_mb(&dest_node_acl->acl_pr_ref_count);
3268 		dest_node_acl = NULL;
3269 		ret = TCM_INVALID_PARAMETER_LIST;
3270 		goto out;
3271 	}
3272 
3273 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3274 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3275 		dest_node_acl->initiatorname);
3276 
3277 	/*
3278 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3279 	 * PORT IDENTIFIER.
3280 	 */
3281 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3282 	if (!dest_se_deve) {
3283 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3284 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3285 		ret = TCM_INVALID_PARAMETER_LIST;
3286 		goto out;
3287 	}
3288 
3289 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3290 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3291 		atomic_dec_mb(&dest_se_deve->pr_ref_count);
3292 		dest_se_deve = NULL;
3293 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3294 		goto out;
3295 	}
3296 
3297 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3298 		" ACL for dest_se_deve->mapped_lun: %u\n",
3299 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3300 		dest_se_deve->mapped_lun);
3301 
3302 	/*
3303 	 * A persistent reservation needs to already existing in order to
3304 	 * successfully complete the REGISTER_AND_MOVE service action..
3305 	 */
3306 	spin_lock(&dev->dev_reservation_lock);
3307 	pr_res_holder = dev->dev_pr_res_holder;
3308 	if (!pr_res_holder) {
3309 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3310 			" currently held\n");
3311 		spin_unlock(&dev->dev_reservation_lock);
3312 		ret = TCM_INVALID_CDB_FIELD;
3313 		goto out;
3314 	}
3315 	/*
3316 	 * The received on I_T Nexus must be the reservation holder.
3317 	 *
3318 	 * From spc4r17 section 5.7.8  Table 50 --
3319 	 * 	Register behaviors for a REGISTER AND MOVE service action
3320 	 */
3321 	if (pr_res_holder != pr_reg) {
3322 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3323 			" Nexus is not reservation holder\n");
3324 		spin_unlock(&dev->dev_reservation_lock);
3325 		ret = TCM_RESERVATION_CONFLICT;
3326 		goto out;
3327 	}
3328 	/*
3329 	 * From spc4r17 section 5.7.8: registering and moving reservation
3330 	 *
3331 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3332 	 * action is received and the established persistent reservation is a
3333 	 * Write Exclusive - All Registrants type or Exclusive Access -
3334 	 * All Registrants type reservation, then the command shall be completed
3335 	 * with RESERVATION CONFLICT status.
3336 	 */
3337 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3338 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3339 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3340 			" reservation for type: %s\n",
3341 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3342 		spin_unlock(&dev->dev_reservation_lock);
3343 		ret = TCM_RESERVATION_CONFLICT;
3344 		goto out;
3345 	}
3346 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3347 	/*
3348 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3349 	 */
3350 	type = pr_res_holder->pr_res_type;
3351 	scope = pr_res_holder->pr_res_type;
3352 	/*
3353 	 * c) Associate the reservation key specified in the SERVICE ACTION
3354 	 *    RESERVATION KEY field with the I_T nexus specified as the
3355 	 *    destination of the register and move, where:
3356 	 *    A) The I_T nexus is specified by the TransportID and the
3357 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3358 	 *    B) Regardless of the TransportID format used, the association for
3359 	 *       the initiator port is based on either the initiator port name
3360 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3361 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3362 	 *       transport protocols where port names are not required;
3363 	 * d) Register the reservation key specified in the SERVICE ACTION
3364 	 *    RESERVATION KEY field;
3365 	 * e) Retain the reservation key specified in the SERVICE ACTION
3366 	 *    RESERVATION KEY field and associated information;
3367 	 *
3368 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3369 	 * register an I_T nexus that is already registered with the same
3370 	 * reservation key or a different reservation key.
3371 	 */
3372 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3373 					iport_ptr);
3374 	if (!dest_pr_reg) {
3375 		if (core_scsi3_alloc_registration(cmd->se_dev,
3376 				dest_node_acl, dest_se_deve, iport_ptr,
3377 				sa_res_key, 0, aptpl, 2, 1)) {
3378 			spin_unlock(&dev->dev_reservation_lock);
3379 			ret = TCM_INVALID_PARAMETER_LIST;
3380 			goto out;
3381 		}
3382 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3383 						iport_ptr);
3384 		new_reg = 1;
3385 	}
3386 	/*
3387 	 * f) Release the persistent reservation for the persistent reservation
3388 	 *    holder (i.e., the I_T nexus on which the
3389 	 */
3390 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3391 			dev->dev_pr_res_holder, 0);
3392 	/*
3393 	 * g) Move the persistent reservation to the specified I_T nexus using
3394 	 *    the same scope and type as the persistent reservation released in
3395 	 *    item f); and
3396 	 */
3397 	dev->dev_pr_res_holder = dest_pr_reg;
3398 	dest_pr_reg->pr_res_holder = 1;
3399 	dest_pr_reg->pr_res_type = type;
3400 	pr_reg->pr_res_scope = scope;
3401 	core_pr_dump_initiator_port(pr_reg, i_buf, PR_REG_ISID_ID_LEN);
3402 	/*
3403 	 * Increment PRGeneration for existing registrations..
3404 	 */
3405 	if (!new_reg)
3406 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3407 	spin_unlock(&dev->dev_reservation_lock);
3408 
3409 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3410 		" created new reservation holder TYPE: %s on object RTPI:"
3411 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3412 		core_scsi3_pr_dump_type(type), rtpi,
3413 		dest_pr_reg->pr_res_generation);
3414 	pr_debug("SPC-3 PR Successfully moved reservation from"
3415 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3416 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3417 		i_buf, dest_tf_ops->get_fabric_name(),
3418 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3419 		iport_ptr : "");
3420 	/*
3421 	 * It is now safe to release configfs group dependencies for destination
3422 	 * of Transport ID Initiator Device/Port Identifier
3423 	 */
3424 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3425 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3426 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3427 	/*
3428 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3429 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3430 	 */
3431 	if (unreg) {
3432 		spin_lock(&pr_tmpl->registration_lock);
3433 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3434 		spin_unlock(&pr_tmpl->registration_lock);
3435 	} else
3436 		core_scsi3_put_pr_reg(pr_reg);
3437 
3438 	core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
3439 
3440 	transport_kunmap_data_sg(cmd);
3441 
3442 	core_scsi3_put_pr_reg(dest_pr_reg);
3443 	return 0;
3444 out:
3445 	if (buf)
3446 		transport_kunmap_data_sg(cmd);
3447 	if (dest_se_deve)
3448 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3449 	if (dest_node_acl)
3450 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3451 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3452 
3453 out_put_pr_reg:
3454 	core_scsi3_put_pr_reg(pr_reg);
3455 	return ret;
3456 }
3457 
3458 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3459 {
3460 	unsigned int __v1, __v2;
3461 
3462 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3463 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3464 
3465 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3466 }
3467 
3468 /*
3469  * See spc4r17 section 6.14 Table 170
3470  */
3471 sense_reason_t
3472 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3473 {
3474 	struct se_device *dev = cmd->se_dev;
3475 	unsigned char *cdb = &cmd->t_task_cdb[0];
3476 	unsigned char *buf;
3477 	u64 res_key, sa_res_key;
3478 	int sa, scope, type, aptpl;
3479 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3480 	sense_reason_t ret;
3481 
3482 	/*
3483 	 * Following spc2r20 5.5.1 Reservations overview:
3484 	 *
3485 	 * If a logical unit has been reserved by any RESERVE command and is
3486 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3487 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3488 	 * initiator or service action and shall terminate with a RESERVATION
3489 	 * CONFLICT status.
3490 	 */
3491 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3492 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3493 			" SPC-2 reservation is held, returning"
3494 			" RESERVATION_CONFLICT\n");
3495 		return TCM_RESERVATION_CONFLICT;
3496 	}
3497 
3498 	/*
3499 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3500 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3501 	 */
3502 	if (!cmd->se_sess)
3503 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3504 
3505 	if (cmd->data_length < 24) {
3506 		pr_warn("SPC-PR: Received PR OUT parameter list"
3507 			" length too small: %u\n", cmd->data_length);
3508 		return TCM_INVALID_PARAMETER_LIST;
3509 	}
3510 
3511 	/*
3512 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3513 	 */
3514 	sa = (cdb[1] & 0x1f);
3515 	scope = (cdb[2] & 0xf0);
3516 	type = (cdb[2] & 0x0f);
3517 
3518 	buf = transport_kmap_data_sg(cmd);
3519 	if (!buf)
3520 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3521 
3522 	/*
3523 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3524 	 */
3525 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3526 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3527 	/*
3528 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3529 	 * SCSI TransportIDs.
3530 	 */
3531 	if (sa != PRO_REGISTER_AND_MOVE) {
3532 		spec_i_pt = (buf[20] & 0x08);
3533 		all_tg_pt = (buf[20] & 0x04);
3534 		aptpl = (buf[20] & 0x01);
3535 	} else {
3536 		aptpl = (buf[17] & 0x01);
3537 		unreg = (buf[17] & 0x02);
3538 	}
3539 	/*
3540 	 * If the backend device has been configured to force APTPL metadata
3541 	 * write-out, go ahead and propigate aptpl=1 down now.
3542 	 */
3543 	if (dev->dev_attrib.force_pr_aptpl)
3544 		aptpl = 1;
3545 
3546 	transport_kunmap_data_sg(cmd);
3547 	buf = NULL;
3548 
3549 	/*
3550 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3551 	 */
3552 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER))
3553 		return TCM_INVALID_PARAMETER_LIST;
3554 
3555 	/*
3556 	 * From spc4r17 section 6.14:
3557 	 *
3558 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3559 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3560 	 * the command shall be terminated with CHECK CONDITION status, with
3561 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3562 	 * code set to PARAMETER LIST LENGTH ERROR.
3563 	 */
3564 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3565 	    (cmd->data_length != 24)) {
3566 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3567 			" list length: %u\n", cmd->data_length);
3568 		return TCM_INVALID_PARAMETER_LIST;
3569 	}
3570 
3571 	/*
3572 	 * (core_scsi3_emulate_pro_* function parameters
3573 	 * are defined by spc4r17 Table 174:
3574 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3575 	 */
3576 	switch (sa) {
3577 	case PRO_REGISTER:
3578 		ret = core_scsi3_emulate_pro_register(cmd,
3579 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER);
3580 		break;
3581 	case PRO_RESERVE:
3582 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3583 		break;
3584 	case PRO_RELEASE:
3585 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3586 		break;
3587 	case PRO_CLEAR:
3588 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3589 		break;
3590 	case PRO_PREEMPT:
3591 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3592 					res_key, sa_res_key, PREEMPT);
3593 		break;
3594 	case PRO_PREEMPT_AND_ABORT:
3595 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3596 					res_key, sa_res_key, PREEMPT_AND_ABORT);
3597 		break;
3598 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3599 		ret = core_scsi3_emulate_pro_register(cmd,
3600 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, REGISTER_AND_IGNORE_EXISTING_KEY);
3601 		break;
3602 	case PRO_REGISTER_AND_MOVE:
3603 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3604 				sa_res_key, aptpl, unreg);
3605 		break;
3606 	default:
3607 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3608 			" action: 0x%02x\n", cdb[1] & 0x1f);
3609 		return TCM_INVALID_CDB_FIELD;
3610 	}
3611 
3612 	if (!ret)
3613 		target_complete_cmd(cmd, GOOD);
3614 	return ret;
3615 }
3616 
3617 /*
3618  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3619  *
3620  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3621  */
3622 static sense_reason_t
3623 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3624 {
3625 	struct se_device *dev = cmd->se_dev;
3626 	struct t10_pr_registration *pr_reg;
3627 	unsigned char *buf;
3628 	u32 add_len = 0, off = 8;
3629 
3630 	if (cmd->data_length < 8) {
3631 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3632 			" too small\n", cmd->data_length);
3633 		return TCM_INVALID_CDB_FIELD;
3634 	}
3635 
3636 	buf = transport_kmap_data_sg(cmd);
3637 	if (!buf)
3638 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3639 
3640 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3641 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3642 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3643 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3644 
3645 	spin_lock(&dev->t10_pr.registration_lock);
3646 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3647 			pr_reg_list) {
3648 		/*
3649 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3650 		 * next reservation key list descriptor.
3651 		 */
3652 		if ((add_len + 8) > (cmd->data_length - 8))
3653 			break;
3654 
3655 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3656 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3657 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3658 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3659 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3660 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3661 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3662 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3663 
3664 		add_len += 8;
3665 	}
3666 	spin_unlock(&dev->t10_pr.registration_lock);
3667 
3668 	buf[4] = ((add_len >> 24) & 0xff);
3669 	buf[5] = ((add_len >> 16) & 0xff);
3670 	buf[6] = ((add_len >> 8) & 0xff);
3671 	buf[7] = (add_len & 0xff);
3672 
3673 	transport_kunmap_data_sg(cmd);
3674 
3675 	return 0;
3676 }
3677 
3678 /*
3679  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3680  *
3681  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3682  */
3683 static sense_reason_t
3684 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3685 {
3686 	struct se_device *dev = cmd->se_dev;
3687 	struct t10_pr_registration *pr_reg;
3688 	unsigned char *buf;
3689 	u64 pr_res_key;
3690 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3691 
3692 	if (cmd->data_length < 8) {
3693 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3694 			" too small\n", cmd->data_length);
3695 		return TCM_INVALID_CDB_FIELD;
3696 	}
3697 
3698 	buf = transport_kmap_data_sg(cmd);
3699 	if (!buf)
3700 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3701 
3702 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3703 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3704 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3705 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3706 
3707 	spin_lock(&dev->dev_reservation_lock);
3708 	pr_reg = dev->dev_pr_res_holder;
3709 	if (pr_reg) {
3710 		/*
3711 		 * Set the hardcoded Additional Length
3712 		 */
3713 		buf[4] = ((add_len >> 24) & 0xff);
3714 		buf[5] = ((add_len >> 16) & 0xff);
3715 		buf[6] = ((add_len >> 8) & 0xff);
3716 		buf[7] = (add_len & 0xff);
3717 
3718 		if (cmd->data_length < 22)
3719 			goto err;
3720 
3721 		/*
3722 		 * Set the Reservation key.
3723 		 *
3724 		 * From spc4r17, section 5.7.10:
3725 		 * A persistent reservation holder has its reservation key
3726 		 * returned in the parameter data from a PERSISTENT
3727 		 * RESERVE IN command with READ RESERVATION service action as
3728 		 * follows:
3729 		 * a) For a persistent reservation of the type Write Exclusive
3730 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3731 		 *      the reservation key shall be set to zero; or
3732 		 * b) For all other persistent reservation types, the
3733 		 *    reservation key shall be set to the registered
3734 		 *    reservation key for the I_T nexus that holds the
3735 		 *    persistent reservation.
3736 		 */
3737 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3738 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3739 			pr_res_key = 0;
3740 		else
3741 			pr_res_key = pr_reg->pr_res_key;
3742 
3743 		buf[8] = ((pr_res_key >> 56) & 0xff);
3744 		buf[9] = ((pr_res_key >> 48) & 0xff);
3745 		buf[10] = ((pr_res_key >> 40) & 0xff);
3746 		buf[11] = ((pr_res_key >> 32) & 0xff);
3747 		buf[12] = ((pr_res_key >> 24) & 0xff);
3748 		buf[13] = ((pr_res_key >> 16) & 0xff);
3749 		buf[14] = ((pr_res_key >> 8) & 0xff);
3750 		buf[15] = (pr_res_key & 0xff);
3751 		/*
3752 		 * Set the SCOPE and TYPE
3753 		 */
3754 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3755 			  (pr_reg->pr_res_type & 0x0f);
3756 	}
3757 
3758 err:
3759 	spin_unlock(&dev->dev_reservation_lock);
3760 	transport_kunmap_data_sg(cmd);
3761 
3762 	return 0;
3763 }
3764 
3765 /*
3766  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3767  *
3768  * See spc4r17 section 6.13.4 Table 165
3769  */
3770 static sense_reason_t
3771 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3772 {
3773 	struct se_device *dev = cmd->se_dev;
3774 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3775 	unsigned char *buf;
3776 	u16 add_len = 8; /* Hardcoded to 8. */
3777 
3778 	if (cmd->data_length < 6) {
3779 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3780 			" %u too small\n", cmd->data_length);
3781 		return TCM_INVALID_CDB_FIELD;
3782 	}
3783 
3784 	buf = transport_kmap_data_sg(cmd);
3785 	if (!buf)
3786 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3787 
3788 	buf[0] = ((add_len >> 8) & 0xff);
3789 	buf[1] = (add_len & 0xff);
3790 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3791 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3792 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3793 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3794 	/*
3795 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3796 	 * set the TMV: Task Mask Valid bit.
3797 	 */
3798 	buf[3] |= 0x80;
3799 	/*
3800 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3801 	 */
3802 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3803 	/*
3804 	 * PTPL_A: Persistence across Target Power Loss Active bit
3805 	 */
3806 	if (pr_tmpl->pr_aptpl_active)
3807 		buf[3] |= 0x01;
3808 	/*
3809 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3810 	 */
3811 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3812 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3813 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3814 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3815 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3816 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3817 
3818 	transport_kunmap_data_sg(cmd);
3819 
3820 	return 0;
3821 }
3822 
3823 /*
3824  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
3825  *
3826  * See spc4r17 section 6.13.5 Table 168 and 169
3827  */
3828 static sense_reason_t
3829 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
3830 {
3831 	struct se_device *dev = cmd->se_dev;
3832 	struct se_node_acl *se_nacl;
3833 	struct se_portal_group *se_tpg;
3834 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
3835 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3836 	unsigned char *buf;
3837 	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
3838 	u32 off = 8; /* off into first Full Status descriptor */
3839 	int format_code = 0;
3840 
3841 	if (cmd->data_length < 8) {
3842 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
3843 			" too small\n", cmd->data_length);
3844 		return TCM_INVALID_CDB_FIELD;
3845 	}
3846 
3847 	buf = transport_kmap_data_sg(cmd);
3848 	if (!buf)
3849 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3850 
3851 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3852 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3853 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3854 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3855 
3856 	spin_lock(&pr_tmpl->registration_lock);
3857 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3858 			&pr_tmpl->registration_list, pr_reg_list) {
3859 
3860 		se_nacl = pr_reg->pr_reg_nacl;
3861 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
3862 		add_desc_len = 0;
3863 
3864 		atomic_inc_mb(&pr_reg->pr_res_holders);
3865 		spin_unlock(&pr_tmpl->registration_lock);
3866 		/*
3867 		 * Determine expected length of $FABRIC_MOD specific
3868 		 * TransportID full status descriptor..
3869 		 */
3870 		exp_desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id_len(
3871 				se_tpg, se_nacl, pr_reg, &format_code);
3872 
3873 		if ((exp_desc_len + add_len) > cmd->data_length) {
3874 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
3875 				" out of buffer: %d\n", cmd->data_length);
3876 			spin_lock(&pr_tmpl->registration_lock);
3877 			atomic_dec_mb(&pr_reg->pr_res_holders);
3878 			break;
3879 		}
3880 		/*
3881 		 * Set RESERVATION KEY
3882 		 */
3883 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3884 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3885 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3886 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3887 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3888 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3889 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3890 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3891 		off += 4; /* Skip Over Reserved area */
3892 
3893 		/*
3894 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
3895 		 */
3896 		if (pr_reg->pr_reg_all_tg_pt)
3897 			buf[off] = 0x02;
3898 		/*
3899 		 * The struct se_lun pointer will be present for the
3900 		 * reservation holder for PR_HOLDER bit.
3901 		 *
3902 		 * Also, if this registration is the reservation
3903 		 * holder, fill in SCOPE and TYPE in the next byte.
3904 		 */
3905 		if (pr_reg->pr_res_holder) {
3906 			buf[off++] |= 0x01;
3907 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
3908 				     (pr_reg->pr_res_type & 0x0f);
3909 		} else
3910 			off += 2;
3911 
3912 		off += 4; /* Skip over reserved area */
3913 		/*
3914 		 * From spc4r17 6.3.15:
3915 		 *
3916 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
3917 		 * IDENTIFIER field contains the relative port identifier (see
3918 		 * 3.1.120) of the target port that is part of the I_T nexus
3919 		 * described by this full status descriptor. If the ALL_TG_PT
3920 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
3921 		 * IDENTIFIER field are not defined by this standard.
3922 		 */
3923 		if (!pr_reg->pr_reg_all_tg_pt) {
3924 			struct se_port *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
3925 
3926 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
3927 			buf[off++] = (port->sep_rtpi & 0xff);
3928 		} else
3929 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
3930 
3931 		/*
3932 		 * Now, have the $FABRIC_MOD fill in the protocol identifier
3933 		 */
3934 		desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id(se_tpg,
3935 				se_nacl, pr_reg, &format_code, &buf[off+4]);
3936 
3937 		spin_lock(&pr_tmpl->registration_lock);
3938 		atomic_dec_mb(&pr_reg->pr_res_holders);
3939 		/*
3940 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
3941 		 */
3942 		buf[off++] = ((desc_len >> 24) & 0xff);
3943 		buf[off++] = ((desc_len >> 16) & 0xff);
3944 		buf[off++] = ((desc_len >> 8) & 0xff);
3945 		buf[off++] = (desc_len & 0xff);
3946 		/*
3947 		 * Size of full desctipor header minus TransportID
3948 		 * containing $FABRIC_MOD specific) initiator device/port
3949 		 * WWN information.
3950 		 *
3951 		 *  See spc4r17 Section 6.13.5 Table 169
3952 		 */
3953 		add_desc_len = (24 + desc_len);
3954 
3955 		off += desc_len;
3956 		add_len += add_desc_len;
3957 	}
3958 	spin_unlock(&pr_tmpl->registration_lock);
3959 	/*
3960 	 * Set ADDITIONAL_LENGTH
3961 	 */
3962 	buf[4] = ((add_len >> 24) & 0xff);
3963 	buf[5] = ((add_len >> 16) & 0xff);
3964 	buf[6] = ((add_len >> 8) & 0xff);
3965 	buf[7] = (add_len & 0xff);
3966 
3967 	transport_kunmap_data_sg(cmd);
3968 
3969 	return 0;
3970 }
3971 
3972 sense_reason_t
3973 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
3974 {
3975 	sense_reason_t ret;
3976 
3977 	/*
3978 	 * Following spc2r20 5.5.1 Reservations overview:
3979 	 *
3980 	 * If a logical unit has been reserved by any RESERVE command and is
3981 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3982 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3983 	 * initiator or service action and shall terminate with a RESERVATION
3984 	 * CONFLICT status.
3985 	 */
3986 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3987 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3988 			" SPC-2 reservation is held, returning"
3989 			" RESERVATION_CONFLICT\n");
3990 		return TCM_RESERVATION_CONFLICT;
3991 	}
3992 
3993 	switch (cmd->t_task_cdb[1] & 0x1f) {
3994 	case PRI_READ_KEYS:
3995 		ret = core_scsi3_pri_read_keys(cmd);
3996 		break;
3997 	case PRI_READ_RESERVATION:
3998 		ret = core_scsi3_pri_read_reservation(cmd);
3999 		break;
4000 	case PRI_REPORT_CAPABILITIES:
4001 		ret = core_scsi3_pri_report_capabilities(cmd);
4002 		break;
4003 	case PRI_READ_FULL_STATUS:
4004 		ret = core_scsi3_pri_read_full_status(cmd);
4005 		break;
4006 	default:
4007 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4008 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4009 		return TCM_INVALID_CDB_FIELD;
4010 	}
4011 
4012 	if (!ret)
4013 		target_complete_cmd(cmd, GOOD);
4014 	return ret;
4015 }
4016 
4017 sense_reason_t
4018 target_check_reservation(struct se_cmd *cmd)
4019 {
4020 	struct se_device *dev = cmd->se_dev;
4021 	sense_reason_t ret;
4022 
4023 	if (!cmd->se_sess)
4024 		return 0;
4025 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4026 		return 0;
4027 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
4028 		return 0;
4029 
4030 	spin_lock(&dev->dev_reservation_lock);
4031 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4032 		ret = target_scsi2_reservation_check(cmd);
4033 	else
4034 		ret = target_scsi3_pr_reservation_check(cmd);
4035 	spin_unlock(&dev->dev_reservation_lock);
4036 
4037 	return ret;
4038 }
4039