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 2009-2012 RisingTide Systems LLC.
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 int 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 		return 0;
63 
64 	snprintf(buf, size, ",i,0x%s", &pr_reg->pr_reg_isid[0]);
65 	return 1;
66 }
67 
68 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
69 			struct t10_pr_registration *, int);
70 
71 static sense_reason_t
72 target_scsi2_reservation_check(struct se_cmd *cmd)
73 {
74 	struct se_device *dev = cmd->se_dev;
75 	struct se_session *sess = cmd->se_sess;
76 
77 	switch (cmd->t_task_cdb[0]) {
78 	case INQUIRY:
79 	case RELEASE:
80 	case RELEASE_10:
81 		return 0;
82 	default:
83 		break;
84 	}
85 
86 	if (!dev->dev_reserved_node_acl || !sess)
87 		return 0;
88 
89 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
90 		return TCM_RESERVATION_CONFLICT;
91 
92 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
93 		if (dev->dev_res_bin_isid != sess->sess_bin_isid)
94 			return TCM_RESERVATION_CONFLICT;
95 	}
96 
97 	return 0;
98 }
99 
100 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
101 					struct se_node_acl *, struct se_session *);
102 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
103 
104 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
105 {
106 	struct se_session *se_sess = cmd->se_sess;
107 	struct se_device *dev = cmd->se_dev;
108 	struct t10_pr_registration *pr_reg;
109 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
110 	int conflict = 0;
111 
112 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
113 			se_sess);
114 	if (pr_reg) {
115 		/*
116 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
117 		 * behavior
118 		 *
119 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
120 		 * status, but no reservation shall be established and the
121 		 * persistent reservation shall not be changed, if the command
122 		 * is received from a) and b) below.
123 		 *
124 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
125 		 * status, but the persistent reservation shall not be released,
126 		 * if the command is received from a) and b)
127 		 *
128 		 * a) An I_T nexus that is a persistent reservation holder; or
129 		 * b) An I_T nexus that is registered if a registrants only or
130 		 *    all registrants type persistent reservation is present.
131 		 *
132 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
133 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
134 		 * as defined in SPC-2.
135 		 */
136 		if (pr_reg->pr_res_holder) {
137 			core_scsi3_put_pr_reg(pr_reg);
138 			return 1;
139 		}
140 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
141 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
142 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
143 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
144 			core_scsi3_put_pr_reg(pr_reg);
145 			return 1;
146 		}
147 		core_scsi3_put_pr_reg(pr_reg);
148 		conflict = 1;
149 	} else {
150 		/*
151 		 * Following spc2r20 5.5.1 Reservations overview:
152 		 *
153 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
154 		 * command with the REGISTER or the REGISTER AND IGNORE
155 		 * EXISTING KEY service action and is still registered by any
156 		 * initiator, all RESERVE commands and all RELEASE commands
157 		 * regardless of initiator shall conflict and shall terminate
158 		 * with a RESERVATION CONFLICT status.
159 		 */
160 		spin_lock(&pr_tmpl->registration_lock);
161 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
162 		spin_unlock(&pr_tmpl->registration_lock);
163 	}
164 
165 	if (conflict) {
166 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
167 			" while active SPC-3 registrations exist,"
168 			" returning RESERVATION_CONFLICT\n");
169 		return -EBUSY;
170 	}
171 
172 	return 0;
173 }
174 
175 sense_reason_t
176 target_scsi2_reservation_release(struct se_cmd *cmd)
177 {
178 	struct se_device *dev = cmd->se_dev;
179 	struct se_session *sess = cmd->se_sess;
180 	struct se_portal_group *tpg;
181 	int rc;
182 
183 	if (!sess || !sess->se_tpg)
184 		goto out;
185 	rc = target_check_scsi2_reservation_conflict(cmd);
186 	if (rc == 1)
187 		goto out;
188 	if (rc < 0)
189 		return TCM_RESERVATION_CONFLICT;
190 
191 	spin_lock(&dev->dev_reservation_lock);
192 	if (!dev->dev_reserved_node_acl || !sess)
193 		goto out_unlock;
194 
195 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
196 		goto out_unlock;
197 
198 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
199 		goto out_unlock;
200 
201 	dev->dev_reserved_node_acl = NULL;
202 	dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS;
203 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS_WITH_ISID) {
204 		dev->dev_res_bin_isid = 0;
205 		dev->dev_reservation_flags &= ~DRF_SPC2_RESERVATIONS_WITH_ISID;
206 	}
207 	tpg = sess->se_tpg;
208 	pr_debug("SCSI-2 Released reservation for %s LUN: %u ->"
209 		" MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
210 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
211 		sess->se_node_acl->initiatorname);
212 
213 out_unlock:
214 	spin_unlock(&dev->dev_reservation_lock);
215 out:
216 	target_complete_cmd(cmd, GOOD);
217 	return 0;
218 }
219 
220 sense_reason_t
221 target_scsi2_reservation_reserve(struct se_cmd *cmd)
222 {
223 	struct se_device *dev = cmd->se_dev;
224 	struct se_session *sess = cmd->se_sess;
225 	struct se_portal_group *tpg;
226 	sense_reason_t ret = 0;
227 	int rc;
228 
229 	if ((cmd->t_task_cdb[1] & 0x01) &&
230 	    (cmd->t_task_cdb[1] & 0x02)) {
231 		pr_err("LongIO and Obselete Bits set, returning"
232 				" ILLEGAL_REQUEST\n");
233 		return TCM_UNSUPPORTED_SCSI_OPCODE;
234 	}
235 	/*
236 	 * This is currently the case for target_core_mod passthrough struct se_cmd
237 	 * ops
238 	 */
239 	if (!sess || !sess->se_tpg)
240 		goto out;
241 	rc = target_check_scsi2_reservation_conflict(cmd);
242 	if (rc == 1)
243 		goto out;
244 
245 	if (rc < 0)
246 		return TCM_RESERVATION_CONFLICT;
247 
248 	tpg = sess->se_tpg;
249 	spin_lock(&dev->dev_reservation_lock);
250 	if (dev->dev_reserved_node_acl &&
251 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
252 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
253 			tpg->se_tpg_tfo->get_fabric_name());
254 		pr_err("Original reserver LUN: %u %s\n",
255 			cmd->se_lun->unpacked_lun,
256 			dev->dev_reserved_node_acl->initiatorname);
257 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
258 			" from %s \n", cmd->se_lun->unpacked_lun,
259 			cmd->se_deve->mapped_lun,
260 			sess->se_node_acl->initiatorname);
261 		ret = TCM_RESERVATION_CONFLICT;
262 		goto out_unlock;
263 	}
264 
265 	dev->dev_reserved_node_acl = sess->se_node_acl;
266 	dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS;
267 	if (sess->sess_bin_isid != 0) {
268 		dev->dev_res_bin_isid = sess->sess_bin_isid;
269 		dev->dev_reservation_flags |= DRF_SPC2_RESERVATIONS_WITH_ISID;
270 	}
271 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
272 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
273 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
274 		sess->se_node_acl->initiatorname);
275 
276 out_unlock:
277 	spin_unlock(&dev->dev_reservation_lock);
278 out:
279 	if (!ret)
280 		target_complete_cmd(cmd, GOOD);
281 	return ret;
282 }
283 
284 
285 /*
286  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
287  *
288  * This function is called by those initiator ports who are *NOT*
289  * the active PR reservation holder when a reservation is present.
290  */
291 static int core_scsi3_pr_seq_non_holder(
292 	struct se_cmd *cmd,
293 	u32 pr_reg_type)
294 {
295 	unsigned char *cdb = cmd->t_task_cdb;
296 	struct se_dev_entry *se_deve;
297 	struct se_session *se_sess = cmd->se_sess;
298 	int other_cdb = 0, ignore_reg;
299 	int registered_nexus = 0, ret = 1; /* Conflict by default */
300 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
301 	int we = 0; /* Write Exclusive */
302 	int legacy = 0; /* Act like a legacy device and return
303 			 * RESERVATION CONFLICT on some CDBs */
304 
305 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
306 	/*
307 	 * Determine if the registration should be ignored due to
308 	 * non-matching ISIDs in target_scsi3_pr_reservation_check().
309 	 */
310 	ignore_reg = (pr_reg_type & 0x80000000);
311 	if (ignore_reg)
312 		pr_reg_type &= ~0x80000000;
313 
314 	switch (pr_reg_type) {
315 	case PR_TYPE_WRITE_EXCLUSIVE:
316 		we = 1;
317 	case PR_TYPE_EXCLUSIVE_ACCESS:
318 		/*
319 		 * Some commands are only allowed for the persistent reservation
320 		 * holder.
321 		 */
322 		if ((se_deve->def_pr_registered) && !(ignore_reg))
323 			registered_nexus = 1;
324 		break;
325 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
326 		we = 1;
327 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
328 		/*
329 		 * Some commands are only allowed for registered I_T Nexuses.
330 		 */
331 		reg_only = 1;
332 		if ((se_deve->def_pr_registered) && !(ignore_reg))
333 			registered_nexus = 1;
334 		break;
335 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
336 		we = 1;
337 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
338 		/*
339 		 * Each registered I_T Nexus is a reservation holder.
340 		 */
341 		all_reg = 1;
342 		if ((se_deve->def_pr_registered) && !(ignore_reg))
343 			registered_nexus = 1;
344 		break;
345 	default:
346 		return -EINVAL;
347 	}
348 	/*
349 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
350 	 */
351 	switch (cdb[0]) {
352 	case SECURITY_PROTOCOL_IN:
353 		if (registered_nexus)
354 			return 0;
355 		ret = (we) ? 0 : 1;
356 		break;
357 	case MODE_SENSE:
358 	case MODE_SENSE_10:
359 	case READ_ATTRIBUTE:
360 	case READ_BUFFER:
361 	case RECEIVE_DIAGNOSTIC:
362 		if (legacy) {
363 			ret = 1;
364 			break;
365 		}
366 		if (registered_nexus) {
367 			ret = 0;
368 			break;
369 		}
370 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
371 		break;
372 	case PERSISTENT_RESERVE_OUT:
373 		/*
374 		 * This follows PERSISTENT_RESERVE_OUT service actions that
375 		 * are allowed in the presence of various reservations.
376 		 * See spc4r17, table 46
377 		 */
378 		switch (cdb[1] & 0x1f) {
379 		case PRO_CLEAR:
380 		case PRO_PREEMPT:
381 		case PRO_PREEMPT_AND_ABORT:
382 			ret = (registered_nexus) ? 0 : 1;
383 			break;
384 		case PRO_REGISTER:
385 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
386 			ret = 0;
387 			break;
388 		case PRO_REGISTER_AND_MOVE:
389 		case PRO_RESERVE:
390 			ret = 1;
391 			break;
392 		case PRO_RELEASE:
393 			ret = (registered_nexus) ? 0 : 1;
394 			break;
395 		default:
396 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
397 				" action: 0x%02x\n", cdb[1] & 0x1f);
398 			return -EINVAL;
399 		}
400 		break;
401 	case RELEASE:
402 	case RELEASE_10:
403 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
404 		ret = 0;
405 		break;
406 	case RESERVE:
407 	case RESERVE_10:
408 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
409 		ret = 0;
410 		break;
411 	case TEST_UNIT_READY:
412 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
413 		break;
414 	case MAINTENANCE_IN:
415 		switch (cdb[1] & 0x1f) {
416 		case MI_MANAGEMENT_PROTOCOL_IN:
417 			if (registered_nexus) {
418 				ret = 0;
419 				break;
420 			}
421 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
422 			break;
423 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
424 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
425 			if (legacy) {
426 				ret = 1;
427 				break;
428 			}
429 			if (registered_nexus) {
430 				ret = 0;
431 				break;
432 			}
433 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
434 			break;
435 		case MI_REPORT_ALIASES:
436 		case MI_REPORT_IDENTIFYING_INFORMATION:
437 		case MI_REPORT_PRIORITY:
438 		case MI_REPORT_TARGET_PGS:
439 		case MI_REPORT_TIMESTAMP:
440 			ret = 0; /* Allowed */
441 			break;
442 		default:
443 			pr_err("Unknown MI Service Action: 0x%02x\n",
444 				(cdb[1] & 0x1f));
445 			return -EINVAL;
446 		}
447 		break;
448 	case ACCESS_CONTROL_IN:
449 	case ACCESS_CONTROL_OUT:
450 	case INQUIRY:
451 	case LOG_SENSE:
452 	case READ_MEDIA_SERIAL_NUMBER:
453 	case REPORT_LUNS:
454 	case REQUEST_SENSE:
455 	case PERSISTENT_RESERVE_IN:
456 		ret = 0; /*/ Allowed CDBs */
457 		break;
458 	default:
459 		other_cdb = 1;
460 		break;
461 	}
462 	/*
463 	 * Case where the CDB is explicitly allowed in the above switch
464 	 * statement.
465 	 */
466 	if (!ret && !other_cdb) {
467 		pr_debug("Allowing explict CDB: 0x%02x for %s"
468 			" reservation holder\n", cdb[0],
469 			core_scsi3_pr_dump_type(pr_reg_type));
470 
471 		return ret;
472 	}
473 	/*
474 	 * Check if write exclusive initiator ports *NOT* holding the
475 	 * WRITE_EXCLUSIVE_* reservation.
476 	 */
477 	if (we && !registered_nexus) {
478 		if (cmd->data_direction == DMA_TO_DEVICE) {
479 			/*
480 			 * Conflict for write exclusive
481 			 */
482 			pr_debug("%s Conflict for unregistered nexus"
483 				" %s CDB: 0x%02x to %s reservation\n",
484 				transport_dump_cmd_direction(cmd),
485 				se_sess->se_node_acl->initiatorname, cdb[0],
486 				core_scsi3_pr_dump_type(pr_reg_type));
487 			return 1;
488 		} else {
489 			/*
490 			 * Allow non WRITE CDBs for all Write Exclusive
491 			 * PR TYPEs to pass for registered and
492 			 * non-registered_nexuxes NOT holding the reservation.
493 			 *
494 			 * We only make noise for the unregisterd nexuses,
495 			 * as we expect registered non-reservation holding
496 			 * nexuses to issue CDBs.
497 			 */
498 
499 			if (!registered_nexus) {
500 				pr_debug("Allowing implict CDB: 0x%02x"
501 					" for %s reservation on unregistered"
502 					" nexus\n", cdb[0],
503 					core_scsi3_pr_dump_type(pr_reg_type));
504 			}
505 
506 			return 0;
507 		}
508 	} else if ((reg_only) || (all_reg)) {
509 		if (registered_nexus) {
510 			/*
511 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
512 			 * allow commands from registered nexuses.
513 			 */
514 
515 			pr_debug("Allowing implict CDB: 0x%02x for %s"
516 				" reservation\n", cdb[0],
517 				core_scsi3_pr_dump_type(pr_reg_type));
518 
519 			return 0;
520 		}
521 	}
522 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
523 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
524 		(registered_nexus) ? "" : "un",
525 		se_sess->se_node_acl->initiatorname, cdb[0],
526 		core_scsi3_pr_dump_type(pr_reg_type));
527 
528 	return 1; /* Conflict by default */
529 }
530 
531 static sense_reason_t
532 target_scsi3_pr_reservation_check(struct se_cmd *cmd)
533 {
534 	struct se_device *dev = cmd->se_dev;
535 	struct se_session *sess = cmd->se_sess;
536 	u32 pr_reg_type;
537 
538 	if (!dev->dev_pr_res_holder)
539 		return 0;
540 
541 	pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
542 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
543 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl)
544 		goto check_nonholder;
545 
546 	if (dev->dev_pr_res_holder->isid_present_at_reg) {
547 		if (dev->dev_pr_res_holder->pr_reg_bin_isid !=
548 		    sess->sess_bin_isid) {
549 			pr_reg_type |= 0x80000000;
550 			goto check_nonholder;
551 		}
552 	}
553 
554 	return 0;
555 
556 check_nonholder:
557 	if (core_scsi3_pr_seq_non_holder(cmd, pr_reg_type))
558 		return TCM_RESERVATION_CONFLICT;
559 	return 0;
560 }
561 
562 static u32 core_scsi3_pr_generation(struct se_device *dev)
563 {
564 	u32 prg;
565 
566 	/*
567 	 * PRGeneration field shall contain the value of a 32-bit wrapping
568 	 * counter mainted by the device server.
569 	 *
570 	 * Note that this is done regardless of Active Persist across
571 	 * Target PowerLoss (APTPL)
572 	 *
573 	 * See spc4r17 section 6.3.12 READ_KEYS service action
574 	 */
575 	spin_lock(&dev->dev_reservation_lock);
576 	prg = dev->t10_pr.pr_generation++;
577 	spin_unlock(&dev->dev_reservation_lock);
578 
579 	return prg;
580 }
581 
582 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
583 	struct se_device *dev,
584 	struct se_node_acl *nacl,
585 	struct se_dev_entry *deve,
586 	unsigned char *isid,
587 	u64 sa_res_key,
588 	int all_tg_pt,
589 	int aptpl)
590 {
591 	struct t10_pr_registration *pr_reg;
592 
593 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
594 	if (!pr_reg) {
595 		pr_err("Unable to allocate struct t10_pr_registration\n");
596 		return NULL;
597 	}
598 
599 	pr_reg->pr_aptpl_buf = kzalloc(dev->t10_pr.pr_aptpl_buf_len,
600 					GFP_ATOMIC);
601 	if (!pr_reg->pr_aptpl_buf) {
602 		pr_err("Unable to allocate pr_reg->pr_aptpl_buf\n");
603 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
604 		return NULL;
605 	}
606 
607 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
608 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
609 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
610 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
611 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
612 	atomic_set(&pr_reg->pr_res_holders, 0);
613 	pr_reg->pr_reg_nacl = nacl;
614 	pr_reg->pr_reg_deve = deve;
615 	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
616 	pr_reg->pr_aptpl_target_lun = deve->se_lun->unpacked_lun;
617 	pr_reg->pr_res_key = sa_res_key;
618 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
619 	pr_reg->pr_reg_aptpl = aptpl;
620 	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
621 	/*
622 	 * If an ISID value for this SCSI Initiator Port exists,
623 	 * save it to the registration now.
624 	 */
625 	if (isid != NULL) {
626 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
627 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
628 		pr_reg->isid_present_at_reg = 1;
629 	}
630 
631 	return pr_reg;
632 }
633 
634 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
635 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
636 
637 /*
638  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
639  * modes.
640  */
641 static struct t10_pr_registration *__core_scsi3_alloc_registration(
642 	struct se_device *dev,
643 	struct se_node_acl *nacl,
644 	struct se_dev_entry *deve,
645 	unsigned char *isid,
646 	u64 sa_res_key,
647 	int all_tg_pt,
648 	int aptpl)
649 {
650 	struct se_dev_entry *deve_tmp;
651 	struct se_node_acl *nacl_tmp;
652 	struct se_port *port, *port_tmp;
653 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
654 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
655 	int ret;
656 	/*
657 	 * Create a registration for the I_T Nexus upon which the
658 	 * PROUT REGISTER was received.
659 	 */
660 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, deve, isid,
661 			sa_res_key, all_tg_pt, aptpl);
662 	if (!pr_reg)
663 		return NULL;
664 	/*
665 	 * Return pointer to pr_reg for ALL_TG_PT=0
666 	 */
667 	if (!all_tg_pt)
668 		return pr_reg;
669 	/*
670 	 * Create list of matching SCSI Initiator Port registrations
671 	 * for ALL_TG_PT=1
672 	 */
673 	spin_lock(&dev->se_port_lock);
674 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
675 		atomic_inc(&port->sep_tg_pt_ref_cnt);
676 		smp_mb__after_atomic_inc();
677 		spin_unlock(&dev->se_port_lock);
678 
679 		spin_lock_bh(&port->sep_alua_lock);
680 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
681 					alua_port_list) {
682 			/*
683 			 * This pointer will be NULL for demo mode MappedLUNs
684 			 * that have not been make explict via a ConfigFS
685 			 * MappedLUN group for the SCSI Initiator Node ACL.
686 			 */
687 			if (!deve_tmp->se_lun_acl)
688 				continue;
689 
690 			nacl_tmp = deve_tmp->se_lun_acl->se_lun_nacl;
691 			/*
692 			 * Skip the matching struct se_node_acl that is allocated
693 			 * above..
694 			 */
695 			if (nacl == nacl_tmp)
696 				continue;
697 			/*
698 			 * Only perform PR registrations for target ports on
699 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
700 			 * arrived.
701 			 */
702 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
703 				continue;
704 			/*
705 			 * Look for a matching Initiator Node ACL in ASCII format
706 			 */
707 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
708 				continue;
709 
710 			atomic_inc(&deve_tmp->pr_ref_count);
711 			smp_mb__after_atomic_inc();
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(&port->sep_tg_pt_ref_cnt);
724 				smp_mb__after_atomic_dec();
725 				atomic_dec(&deve_tmp->pr_ref_count);
726 				smp_mb__after_atomic_dec();
727 				goto out;
728 			}
729 			/*
730 			 * Located a matching SCSI Initiator Port on a different
731 			 * port, allocate the pr_reg_atp and attach it to the
732 			 * pr_reg->pr_reg_atp_list that will be processed once
733 			 * the original *pr_reg is processed in
734 			 * __core_scsi3_add_registration()
735 			 */
736 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
737 						nacl_tmp, deve_tmp, NULL,
738 						sa_res_key, all_tg_pt, aptpl);
739 			if (!pr_reg_atp) {
740 				atomic_dec(&port->sep_tg_pt_ref_cnt);
741 				smp_mb__after_atomic_dec();
742 				atomic_dec(&deve_tmp->pr_ref_count);
743 				smp_mb__after_atomic_dec();
744 				core_scsi3_lunacl_undepend_item(deve_tmp);
745 				goto out;
746 			}
747 
748 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
749 				      &pr_reg->pr_reg_atp_list);
750 			spin_lock_bh(&port->sep_alua_lock);
751 		}
752 		spin_unlock_bh(&port->sep_alua_lock);
753 
754 		spin_lock(&dev->se_port_lock);
755 		atomic_dec(&port->sep_tg_pt_ref_cnt);
756 		smp_mb__after_atomic_dec();
757 	}
758 	spin_unlock(&dev->se_port_lock);
759 
760 	return pr_reg;
761 out:
762 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
763 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
764 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
765 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
766 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
767 	}
768 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
769 	return NULL;
770 }
771 
772 int core_scsi3_alloc_aptpl_registration(
773 	struct t10_reservation *pr_tmpl,
774 	u64 sa_res_key,
775 	unsigned char *i_port,
776 	unsigned char *isid,
777 	u32 mapped_lun,
778 	unsigned char *t_port,
779 	u16 tpgt,
780 	u32 target_lun,
781 	int res_holder,
782 	int all_tg_pt,
783 	u8 type)
784 {
785 	struct t10_pr_registration *pr_reg;
786 
787 	if (!i_port || !t_port || !sa_res_key) {
788 		pr_err("Illegal parameters for APTPL registration\n");
789 		return -EINVAL;
790 	}
791 
792 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
793 	if (!pr_reg) {
794 		pr_err("Unable to allocate struct t10_pr_registration\n");
795 		return -ENOMEM;
796 	}
797 	pr_reg->pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len, GFP_KERNEL);
798 
799 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
800 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
801 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
802 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
803 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
804 	atomic_set(&pr_reg->pr_res_holders, 0);
805 	pr_reg->pr_reg_nacl = NULL;
806 	pr_reg->pr_reg_deve = NULL;
807 	pr_reg->pr_res_mapped_lun = mapped_lun;
808 	pr_reg->pr_aptpl_target_lun = target_lun;
809 	pr_reg->pr_res_key = sa_res_key;
810 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
811 	pr_reg->pr_reg_aptpl = 1;
812 	pr_reg->pr_reg_tg_pt_lun = NULL;
813 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
814 	pr_reg->pr_res_type = type;
815 	/*
816 	 * If an ISID value had been saved in APTPL metadata for this
817 	 * SCSI Initiator Port, restore it now.
818 	 */
819 	if (isid != NULL) {
820 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
821 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
822 		pr_reg->isid_present_at_reg = 1;
823 	}
824 	/*
825 	 * Copy the i_port and t_port information from caller.
826 	 */
827 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
828 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
829 	pr_reg->pr_reg_tpgt = tpgt;
830 	/*
831 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
832 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
833 	 * the Initiator Node LUN ACL from the fabric module is created for
834 	 * this registration.
835 	 */
836 	pr_reg->pr_res_holder = res_holder;
837 
838 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
839 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
840 			" metadata\n", (res_holder) ? "+reservation" : "");
841 	return 0;
842 }
843 
844 static void core_scsi3_aptpl_reserve(
845 	struct se_device *dev,
846 	struct se_portal_group *tpg,
847 	struct se_node_acl *node_acl,
848 	struct t10_pr_registration *pr_reg)
849 {
850 	char i_buf[PR_REG_ISID_ID_LEN];
851 	int prf_isid;
852 
853 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
854 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
855 				PR_REG_ISID_ID_LEN);
856 
857 	spin_lock(&dev->dev_reservation_lock);
858 	dev->dev_pr_res_holder = pr_reg;
859 	spin_unlock(&dev->dev_reservation_lock);
860 
861 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
862 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
863 		tpg->se_tpg_tfo->get_fabric_name(),
864 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
865 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
866 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
867 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
868 		(prf_isid) ? &i_buf[0] : "");
869 }
870 
871 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
872 				struct t10_pr_registration *, int, int);
873 
874 static int __core_scsi3_check_aptpl_registration(
875 	struct se_device *dev,
876 	struct se_portal_group *tpg,
877 	struct se_lun *lun,
878 	u32 target_lun,
879 	struct se_node_acl *nacl,
880 	struct se_dev_entry *deve)
881 {
882 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
883 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
884 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
885 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
886 	u16 tpgt;
887 
888 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
889 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
890 	/*
891 	 * Copy Initiator Port information from struct se_node_acl
892 	 */
893 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
894 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
895 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
896 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
897 	/*
898 	 * Look for the matching registrations+reservation from those
899 	 * created from APTPL metadata.  Note that multiple registrations
900 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
901 	 * TransportIDs.
902 	 */
903 	spin_lock(&pr_tmpl->aptpl_reg_lock);
904 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
905 				pr_reg_aptpl_list) {
906 		if (!strcmp(pr_reg->pr_iport, i_port) &&
907 		     (pr_reg->pr_res_mapped_lun == deve->mapped_lun) &&
908 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
909 		     (pr_reg->pr_reg_tpgt == tpgt) &&
910 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
911 
912 			pr_reg->pr_reg_nacl = nacl;
913 			pr_reg->pr_reg_deve = deve;
914 			pr_reg->pr_reg_tg_pt_lun = lun;
915 
916 			list_del(&pr_reg->pr_reg_aptpl_list);
917 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
918 			/*
919 			 * At this point all of the pointers in *pr_reg will
920 			 * be setup, so go ahead and add the registration.
921 			 */
922 
923 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
924 			/*
925 			 * If this registration is the reservation holder,
926 			 * make that happen now..
927 			 */
928 			if (pr_reg->pr_res_holder)
929 				core_scsi3_aptpl_reserve(dev, tpg,
930 						nacl, pr_reg);
931 			/*
932 			 * Reenable pr_aptpl_active to accept new metadata
933 			 * updates once the SCSI device is active again..
934 			 */
935 			spin_lock(&pr_tmpl->aptpl_reg_lock);
936 			pr_tmpl->pr_aptpl_active = 1;
937 		}
938 	}
939 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
940 
941 	return 0;
942 }
943 
944 int core_scsi3_check_aptpl_registration(
945 	struct se_device *dev,
946 	struct se_portal_group *tpg,
947 	struct se_lun *lun,
948 	struct se_lun_acl *lun_acl)
949 {
950 	struct se_node_acl *nacl = lun_acl->se_lun_nacl;
951 	struct se_dev_entry *deve = nacl->device_list[lun_acl->mapped_lun];
952 
953 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
954 		return 0;
955 
956 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
957 				lun->unpacked_lun, nacl, deve);
958 }
959 
960 static void __core_scsi3_dump_registration(
961 	struct target_core_fabric_ops *tfo,
962 	struct se_device *dev,
963 	struct se_node_acl *nacl,
964 	struct t10_pr_registration *pr_reg,
965 	int register_type)
966 {
967 	struct se_portal_group *se_tpg = nacl->se_tpg;
968 	char i_buf[PR_REG_ISID_ID_LEN];
969 	int prf_isid;
970 
971 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
972 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
973 				PR_REG_ISID_ID_LEN);
974 
975 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
976 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == 2) ?
977 		"_AND_MOVE" : (register_type == 1) ?
978 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
979 		(prf_isid) ? i_buf : "");
980 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
981 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
982 		tfo->tpg_get_tag(se_tpg));
983 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
984 		" Port(s)\n",  tfo->get_fabric_name(),
985 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
986 		dev->transport->name);
987 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
988 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
989 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
990 		pr_reg->pr_reg_aptpl);
991 }
992 
993 /*
994  * this function can be called with struct se_device->dev_reservation_lock
995  * when register_move = 1
996  */
997 static void __core_scsi3_add_registration(
998 	struct se_device *dev,
999 	struct se_node_acl *nacl,
1000 	struct t10_pr_registration *pr_reg,
1001 	int register_type,
1002 	int register_move)
1003 {
1004 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1005 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1006 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1007 
1008 	/*
1009 	 * Increment PRgeneration counter for struct se_device upon a successful
1010 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1011 	 *
1012 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1013 	 * action, the struct se_device->dev_reservation_lock will already be held,
1014 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1015 	 * for the REGISTER.
1016 	 */
1017 	pr_reg->pr_res_generation = (register_move) ?
1018 			dev->t10_pr.pr_generation++ :
1019 			core_scsi3_pr_generation(dev);
1020 
1021 	spin_lock(&pr_tmpl->registration_lock);
1022 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1023 	pr_reg->pr_reg_deve->def_pr_registered = 1;
1024 
1025 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1026 	spin_unlock(&pr_tmpl->registration_lock);
1027 	/*
1028 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1029 	 */
1030 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1031 		return;
1032 	/*
1033 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1034 	 * allocated in __core_scsi3_alloc_registration()
1035 	 */
1036 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1037 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1038 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1039 
1040 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1041 
1042 		spin_lock(&pr_tmpl->registration_lock);
1043 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1044 			      &pr_tmpl->registration_list);
1045 		pr_reg_tmp->pr_reg_deve->def_pr_registered = 1;
1046 
1047 		__core_scsi3_dump_registration(tfo, dev,
1048 				pr_reg_tmp->pr_reg_nacl, pr_reg_tmp,
1049 				register_type);
1050 		spin_unlock(&pr_tmpl->registration_lock);
1051 		/*
1052 		 * Drop configfs group dependency reference from
1053 		 * __core_scsi3_alloc_registration()
1054 		 */
1055 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1056 	}
1057 }
1058 
1059 static int core_scsi3_alloc_registration(
1060 	struct se_device *dev,
1061 	struct se_node_acl *nacl,
1062 	struct se_dev_entry *deve,
1063 	unsigned char *isid,
1064 	u64 sa_res_key,
1065 	int all_tg_pt,
1066 	int aptpl,
1067 	int register_type,
1068 	int register_move)
1069 {
1070 	struct t10_pr_registration *pr_reg;
1071 
1072 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, deve, isid,
1073 			sa_res_key, all_tg_pt, aptpl);
1074 	if (!pr_reg)
1075 		return -EPERM;
1076 
1077 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1078 			register_type, register_move);
1079 	return 0;
1080 }
1081 
1082 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1083 	struct se_device *dev,
1084 	struct se_node_acl *nacl,
1085 	unsigned char *isid)
1086 {
1087 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1088 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1089 	struct se_portal_group *tpg;
1090 
1091 	spin_lock(&pr_tmpl->registration_lock);
1092 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1093 			&pr_tmpl->registration_list, pr_reg_list) {
1094 		/*
1095 		 * First look for a matching struct se_node_acl
1096 		 */
1097 		if (pr_reg->pr_reg_nacl != nacl)
1098 			continue;
1099 
1100 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1101 		/*
1102 		 * If this registration does NOT contain a fabric provided
1103 		 * ISID, then we have found a match.
1104 		 */
1105 		if (!pr_reg->isid_present_at_reg) {
1106 			/*
1107 			 * Determine if this SCSI device server requires that
1108 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1109 			 * for fabric modules (iSCSI) requiring them.
1110 			 */
1111 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1112 				if (dev->dev_attrib.enforce_pr_isids)
1113 					continue;
1114 			}
1115 			atomic_inc(&pr_reg->pr_res_holders);
1116 			smp_mb__after_atomic_inc();
1117 			spin_unlock(&pr_tmpl->registration_lock);
1118 			return pr_reg;
1119 		}
1120 		/*
1121 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1122 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1123 		 * matching ISID to be provided by the local SCSI Initiator Port.
1124 		 */
1125 		if (!isid)
1126 			continue;
1127 		if (strcmp(isid, pr_reg->pr_reg_isid))
1128 			continue;
1129 
1130 		atomic_inc(&pr_reg->pr_res_holders);
1131 		smp_mb__after_atomic_inc();
1132 		spin_unlock(&pr_tmpl->registration_lock);
1133 		return pr_reg;
1134 	}
1135 	spin_unlock(&pr_tmpl->registration_lock);
1136 
1137 	return NULL;
1138 }
1139 
1140 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1141 	struct se_device *dev,
1142 	struct se_node_acl *nacl,
1143 	struct se_session *sess)
1144 {
1145 	struct se_portal_group *tpg = nacl->se_tpg;
1146 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1147 
1148 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1149 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1150 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1151 					PR_REG_ISID_LEN);
1152 		isid_ptr = &buf[0];
1153 	}
1154 
1155 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1156 }
1157 
1158 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1159 {
1160 	atomic_dec(&pr_reg->pr_res_holders);
1161 	smp_mb__after_atomic_dec();
1162 }
1163 
1164 static int core_scsi3_check_implict_release(
1165 	struct se_device *dev,
1166 	struct t10_pr_registration *pr_reg)
1167 {
1168 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1169 	struct t10_pr_registration *pr_res_holder;
1170 	int ret = 0;
1171 
1172 	spin_lock(&dev->dev_reservation_lock);
1173 	pr_res_holder = dev->dev_pr_res_holder;
1174 	if (!pr_res_holder) {
1175 		spin_unlock(&dev->dev_reservation_lock);
1176 		return ret;
1177 	}
1178 	if (pr_res_holder == pr_reg) {
1179 		/*
1180 		 * Perform an implict RELEASE if the registration that
1181 		 * is being released is holding the reservation.
1182 		 *
1183 		 * From spc4r17, section 5.7.11.1:
1184 		 *
1185 		 * e) If the I_T nexus is the persistent reservation holder
1186 		 *    and the persistent reservation is not an all registrants
1187 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1188 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1189 		 *    service action with the SERVICE ACTION RESERVATION KEY
1190 		 *    field set to zero (see 5.7.11.3).
1191 		 */
1192 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0);
1193 		ret = 1;
1194 		/*
1195 		 * For 'All Registrants' reservation types, all existing
1196 		 * registrations are still processed as reservation holders
1197 		 * in core_scsi3_pr_seq_non_holder() after the initial
1198 		 * reservation holder is implictly released here.
1199 		 */
1200 	} else if (pr_reg->pr_reg_all_tg_pt &&
1201 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1202 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1203 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1204 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1205 			" UNREGISTER while existing reservation with matching"
1206 			" key 0x%016Lx is present from another SCSI Initiator"
1207 			" Port\n", pr_reg->pr_res_key);
1208 		ret = -EPERM;
1209 	}
1210 	spin_unlock(&dev->dev_reservation_lock);
1211 
1212 	return ret;
1213 }
1214 
1215 /*
1216  * Called with struct t10_reservation->registration_lock held.
1217  */
1218 static void __core_scsi3_free_registration(
1219 	struct se_device *dev,
1220 	struct t10_pr_registration *pr_reg,
1221 	struct list_head *preempt_and_abort_list,
1222 	int dec_holders)
1223 {
1224 	struct target_core_fabric_ops *tfo =
1225 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1226 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1227 	char i_buf[PR_REG_ISID_ID_LEN];
1228 	int prf_isid;
1229 
1230 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1231 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1232 				PR_REG_ISID_ID_LEN);
1233 
1234 	pr_reg->pr_reg_deve->def_pr_registered = 0;
1235 	pr_reg->pr_reg_deve->pr_res_key = 0;
1236 	list_del(&pr_reg->pr_reg_list);
1237 	/*
1238 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1239 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1240 	 */
1241 	if (dec_holders)
1242 		core_scsi3_put_pr_reg(pr_reg);
1243 	/*
1244 	 * Wait until all reference from any other I_T nexuses for this
1245 	 * *pr_reg have been released.  Because list_del() is called above,
1246 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1247 	 * count back to zero, and we release *pr_reg.
1248 	 */
1249 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1250 		spin_unlock(&pr_tmpl->registration_lock);
1251 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1252 				tfo->get_fabric_name());
1253 		cpu_relax();
1254 		spin_lock(&pr_tmpl->registration_lock);
1255 	}
1256 
1257 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1258 		" Node: %s%s\n", tfo->get_fabric_name(),
1259 		pr_reg->pr_reg_nacl->initiatorname,
1260 		(prf_isid) ? &i_buf[0] : "");
1261 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1262 		" Port(s)\n", tfo->get_fabric_name(),
1263 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1264 		dev->transport->name);
1265 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1266 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1267 		pr_reg->pr_res_generation);
1268 
1269 	if (!preempt_and_abort_list) {
1270 		pr_reg->pr_reg_deve = NULL;
1271 		pr_reg->pr_reg_nacl = NULL;
1272 		kfree(pr_reg->pr_aptpl_buf);
1273 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1274 		return;
1275 	}
1276 	/*
1277 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1278 	 * are released once the ABORT_TASK_SET has completed..
1279 	 */
1280 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1281 }
1282 
1283 void core_scsi3_free_pr_reg_from_nacl(
1284 	struct se_device *dev,
1285 	struct se_node_acl *nacl)
1286 {
1287 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1288 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1289 	/*
1290 	 * If the passed se_node_acl matches the reservation holder,
1291 	 * release the reservation.
1292 	 */
1293 	spin_lock(&dev->dev_reservation_lock);
1294 	pr_res_holder = dev->dev_pr_res_holder;
1295 	if ((pr_res_holder != NULL) &&
1296 	    (pr_res_holder->pr_reg_nacl == nacl))
1297 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0);
1298 	spin_unlock(&dev->dev_reservation_lock);
1299 	/*
1300 	 * Release any registration associated with the struct se_node_acl.
1301 	 */
1302 	spin_lock(&pr_tmpl->registration_lock);
1303 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1304 			&pr_tmpl->registration_list, pr_reg_list) {
1305 
1306 		if (pr_reg->pr_reg_nacl != nacl)
1307 			continue;
1308 
1309 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1310 	}
1311 	spin_unlock(&pr_tmpl->registration_lock);
1312 }
1313 
1314 void core_scsi3_free_all_registrations(
1315 	struct se_device *dev)
1316 {
1317 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
1318 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1319 
1320 	spin_lock(&dev->dev_reservation_lock);
1321 	pr_res_holder = dev->dev_pr_res_holder;
1322 	if (pr_res_holder != NULL) {
1323 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1324 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1325 				pr_res_holder, 0);
1326 	}
1327 	spin_unlock(&dev->dev_reservation_lock);
1328 
1329 	spin_lock(&pr_tmpl->registration_lock);
1330 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1331 			&pr_tmpl->registration_list, pr_reg_list) {
1332 
1333 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1334 	}
1335 	spin_unlock(&pr_tmpl->registration_lock);
1336 
1337 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1338 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1339 				pr_reg_aptpl_list) {
1340 		list_del(&pr_reg->pr_reg_aptpl_list);
1341 		kfree(pr_reg->pr_aptpl_buf);
1342 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1343 	}
1344 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1345 }
1346 
1347 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1348 {
1349 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1350 			&tpg->tpg_group.cg_item);
1351 }
1352 
1353 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1354 {
1355 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1356 			&tpg->tpg_group.cg_item);
1357 
1358 	atomic_dec(&tpg->tpg_pr_ref_count);
1359 	smp_mb__after_atomic_dec();
1360 }
1361 
1362 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1363 {
1364 	struct se_portal_group *tpg = nacl->se_tpg;
1365 
1366 	if (nacl->dynamic_node_acl)
1367 		return 0;
1368 
1369 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1370 			&nacl->acl_group.cg_item);
1371 }
1372 
1373 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1374 {
1375 	struct se_portal_group *tpg = nacl->se_tpg;
1376 
1377 	if (nacl->dynamic_node_acl) {
1378 		atomic_dec(&nacl->acl_pr_ref_count);
1379 		smp_mb__after_atomic_dec();
1380 		return;
1381 	}
1382 
1383 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1384 			&nacl->acl_group.cg_item);
1385 
1386 	atomic_dec(&nacl->acl_pr_ref_count);
1387 	smp_mb__after_atomic_dec();
1388 }
1389 
1390 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1391 {
1392 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1393 	struct se_node_acl *nacl;
1394 	struct se_portal_group *tpg;
1395 	/*
1396 	 * For nacl->dynamic_node_acl=1
1397 	 */
1398 	if (!lun_acl)
1399 		return 0;
1400 
1401 	nacl = lun_acl->se_lun_nacl;
1402 	tpg = nacl->se_tpg;
1403 
1404 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1405 			&lun_acl->se_lun_group.cg_item);
1406 }
1407 
1408 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1409 {
1410 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1411 	struct se_node_acl *nacl;
1412 	struct se_portal_group *tpg;
1413 	/*
1414 	 * For nacl->dynamic_node_acl=1
1415 	 */
1416 	if (!lun_acl) {
1417 		atomic_dec(&se_deve->pr_ref_count);
1418 		smp_mb__after_atomic_dec();
1419 		return;
1420 	}
1421 	nacl = lun_acl->se_lun_nacl;
1422 	tpg = nacl->se_tpg;
1423 
1424 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1425 			&lun_acl->se_lun_group.cg_item);
1426 
1427 	atomic_dec(&se_deve->pr_ref_count);
1428 	smp_mb__after_atomic_dec();
1429 }
1430 
1431 static sense_reason_t
1432 core_scsi3_decode_spec_i_port(
1433 	struct se_cmd *cmd,
1434 	struct se_portal_group *tpg,
1435 	unsigned char *l_isid,
1436 	u64 sa_res_key,
1437 	int all_tg_pt,
1438 	int aptpl)
1439 {
1440 	struct se_device *dev = cmd->se_dev;
1441 	struct se_port *tmp_port;
1442 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1443 	struct se_session *se_sess = cmd->se_sess;
1444 	struct se_node_acl *dest_node_acl = NULL;
1445 	struct se_dev_entry *dest_se_deve = NULL, *local_se_deve;
1446 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1447 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1448 	LIST_HEAD(tid_dest_list);
1449 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1450 	struct target_core_fabric_ops *tmp_tf_ops;
1451 	unsigned char *buf;
1452 	unsigned char *ptr, *i_str = NULL, proto_ident, tmp_proto_ident;
1453 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
1454 	sense_reason_t ret;
1455 	u32 tpdl, tid_len = 0;
1456 	int dest_local_nexus, prf_isid;
1457 	u32 dest_rtpi = 0;
1458 
1459 	memset(dest_iport, 0, 64);
1460 
1461 	local_se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
1462 	/*
1463 	 * Allocate a struct pr_transport_id_holder and setup the
1464 	 * local_node_acl and local_se_deve pointers and add to
1465 	 * struct list_head tid_dest_list for add registration
1466 	 * processing in the loop of tid_dest_list below.
1467 	 */
1468 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1469 	if (!tidh_new) {
1470 		pr_err("Unable to allocate tidh_new\n");
1471 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1472 	}
1473 	INIT_LIST_HEAD(&tidh_new->dest_list);
1474 	tidh_new->dest_tpg = tpg;
1475 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1476 	tidh_new->dest_se_deve = local_se_deve;
1477 
1478 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1479 				se_sess->se_node_acl, local_se_deve, l_isid,
1480 				sa_res_key, all_tg_pt, aptpl);
1481 	if (!local_pr_reg) {
1482 		kfree(tidh_new);
1483 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1484 	}
1485 	tidh_new->dest_pr_reg = local_pr_reg;
1486 	/*
1487 	 * The local I_T nexus does not hold any configfs dependances,
1488 	 * so we set tid_h->dest_local_nexus=1 to prevent the
1489 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1490 	 */
1491 	tidh_new->dest_local_nexus = 1;
1492 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1493 
1494 	if (cmd->data_length < 28) {
1495 		pr_warn("SPC-PR: Received PR OUT parameter list"
1496 			" length too small: %u\n", cmd->data_length);
1497 		ret = TCM_INVALID_PARAMETER_LIST;
1498 		goto out;
1499 	}
1500 
1501 	buf = transport_kmap_data_sg(cmd);
1502 	if (!buf) {
1503 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1504 		goto out;
1505 	}
1506 
1507 	/*
1508 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1509 	 * first extract TransportID Parameter Data Length, and make sure
1510 	 * the value matches up to the SCSI expected data transfer length.
1511 	 */
1512 	tpdl = (buf[24] & 0xff) << 24;
1513 	tpdl |= (buf[25] & 0xff) << 16;
1514 	tpdl |= (buf[26] & 0xff) << 8;
1515 	tpdl |= buf[27] & 0xff;
1516 
1517 	if ((tpdl + 28) != cmd->data_length) {
1518 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1519 			" does not equal CDB data_length: %u\n", tpdl,
1520 			cmd->data_length);
1521 		ret = TCM_INVALID_PARAMETER_LIST;
1522 		goto out_unmap;
1523 	}
1524 	/*
1525 	 * Start processing the received transport IDs using the
1526 	 * receiving I_T Nexus portal's fabric dependent methods to
1527 	 * obtain the SCSI Initiator Port/Device Identifiers.
1528 	 */
1529 	ptr = &buf[28];
1530 
1531 	while (tpdl > 0) {
1532 		proto_ident = (ptr[0] & 0x0f);
1533 		dest_tpg = NULL;
1534 
1535 		spin_lock(&dev->se_port_lock);
1536 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1537 			tmp_tpg = tmp_port->sep_tpg;
1538 			if (!tmp_tpg)
1539 				continue;
1540 			tmp_tf_ops = tmp_tpg->se_tpg_tfo;
1541 			if (!tmp_tf_ops)
1542 				continue;
1543 			if (!tmp_tf_ops->get_fabric_proto_ident ||
1544 			    !tmp_tf_ops->tpg_parse_pr_out_transport_id)
1545 				continue;
1546 			/*
1547 			 * Look for the matching proto_ident provided by
1548 			 * the received TransportID
1549 			 */
1550 			tmp_proto_ident = tmp_tf_ops->get_fabric_proto_ident(tmp_tpg);
1551 			if (tmp_proto_ident != proto_ident)
1552 				continue;
1553 			dest_rtpi = tmp_port->sep_rtpi;
1554 
1555 			i_str = tmp_tf_ops->tpg_parse_pr_out_transport_id(
1556 					tmp_tpg, (const char *)ptr, &tid_len,
1557 					&iport_ptr);
1558 			if (!i_str)
1559 				continue;
1560 
1561 			atomic_inc(&tmp_tpg->tpg_pr_ref_count);
1562 			smp_mb__after_atomic_inc();
1563 			spin_unlock(&dev->se_port_lock);
1564 
1565 			if (core_scsi3_tpg_depend_item(tmp_tpg)) {
1566 				pr_err(" core_scsi3_tpg_depend_item()"
1567 					" for tmp_tpg\n");
1568 				atomic_dec(&tmp_tpg->tpg_pr_ref_count);
1569 				smp_mb__after_atomic_dec();
1570 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1571 				goto out_unmap;
1572 			}
1573 			/*
1574 			 * Locate the destination initiator ACL to be registered
1575 			 * from the decoded fabric module specific TransportID
1576 			 * at *i_str.
1577 			 */
1578 			spin_lock_irq(&tmp_tpg->acl_node_lock);
1579 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1580 						tmp_tpg, i_str);
1581 			if (dest_node_acl) {
1582 				atomic_inc(&dest_node_acl->acl_pr_ref_count);
1583 				smp_mb__after_atomic_inc();
1584 			}
1585 			spin_unlock_irq(&tmp_tpg->acl_node_lock);
1586 
1587 			if (!dest_node_acl) {
1588 				core_scsi3_tpg_undepend_item(tmp_tpg);
1589 				spin_lock(&dev->se_port_lock);
1590 				continue;
1591 			}
1592 
1593 			if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
1594 				pr_err("configfs_depend_item() failed"
1595 					" for dest_node_acl->acl_group\n");
1596 				atomic_dec(&dest_node_acl->acl_pr_ref_count);
1597 				smp_mb__after_atomic_dec();
1598 				core_scsi3_tpg_undepend_item(tmp_tpg);
1599 				ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1600 				goto out_unmap;
1601 			}
1602 
1603 			dest_tpg = tmp_tpg;
1604 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1605 				" %s Port RTPI: %hu\n",
1606 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1607 				dest_node_acl->initiatorname, dest_rtpi);
1608 
1609 			spin_lock(&dev->se_port_lock);
1610 			break;
1611 		}
1612 		spin_unlock(&dev->se_port_lock);
1613 
1614 		if (!dest_tpg) {
1615 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1616 					" dest_tpg\n");
1617 			ret = TCM_INVALID_PARAMETER_LIST;
1618 			goto out_unmap;
1619 		}
1620 
1621 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1622 			" tid_len: %d for %s + %s\n",
1623 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1624 			tpdl, tid_len, i_str, iport_ptr);
1625 
1626 		if (tid_len > tpdl) {
1627 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1628 				" %u for Transport ID: %s\n", tid_len, ptr);
1629 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1630 			core_scsi3_tpg_undepend_item(dest_tpg);
1631 			ret = TCM_INVALID_PARAMETER_LIST;
1632 			goto out_unmap;
1633 		}
1634 		/*
1635 		 * Locate the desintation struct se_dev_entry pointer for matching
1636 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1637 		 * Target Port.
1638 		 */
1639 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1640 					dest_rtpi);
1641 		if (!dest_se_deve) {
1642 			pr_err("Unable to locate %s dest_se_deve"
1643 				" from destination RTPI: %hu\n",
1644 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1645 				dest_rtpi);
1646 
1647 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1648 			core_scsi3_tpg_undepend_item(dest_tpg);
1649 			ret = TCM_INVALID_PARAMETER_LIST;
1650 			goto out_unmap;
1651 		}
1652 
1653 		if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
1654 			pr_err("core_scsi3_lunacl_depend_item()"
1655 					" failed\n");
1656 			atomic_dec(&dest_se_deve->pr_ref_count);
1657 			smp_mb__after_atomic_dec();
1658 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1659 			core_scsi3_tpg_undepend_item(dest_tpg);
1660 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1661 			goto out_unmap;
1662 		}
1663 
1664 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1665 			" dest_se_deve mapped_lun: %u\n",
1666 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1667 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1668 
1669 		/*
1670 		 * Skip any TransportIDs that already have a registration for
1671 		 * this target port.
1672 		 */
1673 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1674 					iport_ptr);
1675 		if (pr_reg_e) {
1676 			core_scsi3_put_pr_reg(pr_reg_e);
1677 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1678 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1679 			core_scsi3_tpg_undepend_item(dest_tpg);
1680 			ptr += tid_len;
1681 			tpdl -= tid_len;
1682 			tid_len = 0;
1683 			continue;
1684 		}
1685 		/*
1686 		 * Allocate a struct pr_transport_id_holder and setup
1687 		 * the dest_node_acl and dest_se_deve pointers for the
1688 		 * loop below.
1689 		 */
1690 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1691 				GFP_KERNEL);
1692 		if (!tidh_new) {
1693 			pr_err("Unable to allocate tidh_new\n");
1694 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1695 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1696 			core_scsi3_tpg_undepend_item(dest_tpg);
1697 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1698 			goto out_unmap;
1699 		}
1700 		INIT_LIST_HEAD(&tidh_new->dest_list);
1701 		tidh_new->dest_tpg = dest_tpg;
1702 		tidh_new->dest_node_acl = dest_node_acl;
1703 		tidh_new->dest_se_deve = dest_se_deve;
1704 
1705 		/*
1706 		 * Allocate, but do NOT add the registration for the
1707 		 * TransportID referenced SCSI Initiator port.  This
1708 		 * done because of the following from spc4r17 in section
1709 		 * 6.14.3 wrt SPEC_I_PT:
1710 		 *
1711 		 * "If a registration fails for any initiator port (e.g., if th
1712 		 * logical unit does not have enough resources available to
1713 		 * hold the registration information), no registrations shall be
1714 		 * made, and the command shall be terminated with
1715 		 * CHECK CONDITION status."
1716 		 *
1717 		 * That means we call __core_scsi3_alloc_registration() here,
1718 		 * and then call __core_scsi3_add_registration() in the
1719 		 * 2nd loop which will never fail.
1720 		 */
1721 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1722 				dest_node_acl, dest_se_deve, iport_ptr,
1723 				sa_res_key, all_tg_pt, aptpl);
1724 		if (!dest_pr_reg) {
1725 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1726 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1727 			core_scsi3_tpg_undepend_item(dest_tpg);
1728 			kfree(tidh_new);
1729 			ret = TCM_INVALID_PARAMETER_LIST;
1730 			goto out_unmap;
1731 		}
1732 		tidh_new->dest_pr_reg = dest_pr_reg;
1733 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1734 
1735 		ptr += tid_len;
1736 		tpdl -= tid_len;
1737 		tid_len = 0;
1738 
1739 	}
1740 
1741 	transport_kunmap_data_sg(cmd);
1742 
1743 	/*
1744 	 * Go ahead and create a registrations from tid_dest_list for the
1745 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1746 	 * and dest_se_deve.
1747 	 *
1748 	 * The SA Reservation Key from the PROUT is set for the
1749 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1750 	 * means that the TransportID Initiator port will be
1751 	 * registered on all of the target ports in the SCSI target device
1752 	 * ALL_TG_PT=0 means the registration will only be for the
1753 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1754 	 * was received.
1755 	 */
1756 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1757 		dest_tpg = tidh->dest_tpg;
1758 		dest_node_acl = tidh->dest_node_acl;
1759 		dest_se_deve = tidh->dest_se_deve;
1760 		dest_pr_reg = tidh->dest_pr_reg;
1761 		dest_local_nexus = tidh->dest_local_nexus;
1762 
1763 		list_del(&tidh->dest_list);
1764 		kfree(tidh);
1765 
1766 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1767 		prf_isid = core_pr_dump_initiator_port(dest_pr_reg, &i_buf[0],
1768 						PR_REG_ISID_ID_LEN);
1769 
1770 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1771 					dest_pr_reg, 0, 0);
1772 
1773 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1774 			" registered Transport ID for Node: %s%s Mapped LUN:"
1775 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1776 			dest_node_acl->initiatorname, (prf_isid) ?
1777 			&i_buf[0] : "", dest_se_deve->mapped_lun);
1778 
1779 		if (dest_local_nexus)
1780 			continue;
1781 
1782 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1783 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1784 		core_scsi3_tpg_undepend_item(dest_tpg);
1785 	}
1786 
1787 	return 0;
1788 out_unmap:
1789 	transport_kunmap_data_sg(cmd);
1790 out:
1791 	/*
1792 	 * For the failure case, release everything from tid_dest_list
1793 	 * including *dest_pr_reg and the configfs dependances..
1794 	 */
1795 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1796 		dest_tpg = tidh->dest_tpg;
1797 		dest_node_acl = tidh->dest_node_acl;
1798 		dest_se_deve = tidh->dest_se_deve;
1799 		dest_pr_reg = tidh->dest_pr_reg;
1800 		dest_local_nexus = tidh->dest_local_nexus;
1801 
1802 		list_del(&tidh->dest_list);
1803 		kfree(tidh);
1804 		/*
1805 		 * Release any extra ALL_TG_PT=1 registrations for
1806 		 * the SPEC_I_PT=1 case.
1807 		 */
1808 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1809 				&dest_pr_reg->pr_reg_atp_list,
1810 				pr_reg_atp_mem_list) {
1811 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1812 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1813 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1814 		}
1815 
1816 		kfree(dest_pr_reg->pr_aptpl_buf);
1817 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1818 
1819 		if (dest_local_nexus)
1820 			continue;
1821 
1822 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1823 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1824 		core_scsi3_tpg_undepend_item(dest_tpg);
1825 	}
1826 	return ret;
1827 }
1828 
1829 /*
1830  * Called with struct se_device->dev_reservation_lock held
1831  */
1832 static int __core_scsi3_update_aptpl_buf(
1833 	struct se_device *dev,
1834 	unsigned char *buf,
1835 	u32 pr_aptpl_buf_len,
1836 	int clear_aptpl_metadata)
1837 {
1838 	struct se_lun *lun;
1839 	struct se_portal_group *tpg;
1840 	struct t10_pr_registration *pr_reg;
1841 	unsigned char tmp[512], isid_buf[32];
1842 	ssize_t len = 0;
1843 	int reg_count = 0;
1844 
1845 	memset(buf, 0, pr_aptpl_buf_len);
1846 	/*
1847 	 * Called to clear metadata once APTPL has been deactivated.
1848 	 */
1849 	if (clear_aptpl_metadata) {
1850 		snprintf(buf, pr_aptpl_buf_len,
1851 				"No Registrations or Reservations\n");
1852 		return 0;
1853 	}
1854 	/*
1855 	 * Walk the registration list..
1856 	 */
1857 	spin_lock(&dev->t10_pr.registration_lock);
1858 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
1859 			pr_reg_list) {
1860 
1861 		tmp[0] = '\0';
1862 		isid_buf[0] = '\0';
1863 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1864 		lun = pr_reg->pr_reg_tg_pt_lun;
1865 		/*
1866 		 * Write out any ISID value to APTPL metadata that was included
1867 		 * in the original registration.
1868 		 */
1869 		if (pr_reg->isid_present_at_reg)
1870 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1871 					pr_reg->pr_reg_isid);
1872 		/*
1873 		 * Include special metadata if the pr_reg matches the
1874 		 * reservation holder.
1875 		 */
1876 		if (dev->dev_pr_res_holder == pr_reg) {
1877 			snprintf(tmp, 512, "PR_REG_START: %d"
1878 				"\ninitiator_fabric=%s\n"
1879 				"initiator_node=%s\n%s"
1880 				"sa_res_key=%llu\n"
1881 				"res_holder=1\nres_type=%02x\n"
1882 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1883 				"mapped_lun=%u\n", reg_count,
1884 				tpg->se_tpg_tfo->get_fabric_name(),
1885 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1886 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1887 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1888 				pr_reg->pr_res_mapped_lun);
1889 		} else {
1890 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1891 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1892 				"sa_res_key=%llu\nres_holder=0\n"
1893 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1894 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1895 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1896 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1897 				pr_reg->pr_res_mapped_lun);
1898 		}
1899 
1900 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1901 			pr_err("Unable to update renaming"
1902 				" APTPL metadata\n");
1903 			spin_unlock(&dev->t10_pr.registration_lock);
1904 			return -EMSGSIZE;
1905 		}
1906 		len += sprintf(buf+len, "%s", tmp);
1907 
1908 		/*
1909 		 * Include information about the associated SCSI target port.
1910 		 */
1911 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1912 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1913 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1914 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1915 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1916 			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);
1917 
1918 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1919 			pr_err("Unable to update renaming"
1920 				" APTPL metadata\n");
1921 			spin_unlock(&dev->t10_pr.registration_lock);
1922 			return -EMSGSIZE;
1923 		}
1924 		len += sprintf(buf+len, "%s", tmp);
1925 		reg_count++;
1926 	}
1927 	spin_unlock(&dev->t10_pr.registration_lock);
1928 
1929 	if (!reg_count)
1930 		len += sprintf(buf+len, "No Registrations or Reservations");
1931 
1932 	return 0;
1933 }
1934 
1935 static int core_scsi3_update_aptpl_buf(
1936 	struct se_device *dev,
1937 	unsigned char *buf,
1938 	u32 pr_aptpl_buf_len,
1939 	int clear_aptpl_metadata)
1940 {
1941 	int ret;
1942 
1943 	spin_lock(&dev->dev_reservation_lock);
1944 	ret = __core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
1945 				clear_aptpl_metadata);
1946 	spin_unlock(&dev->dev_reservation_lock);
1947 
1948 	return ret;
1949 }
1950 
1951 /*
1952  * Called with struct se_device->aptpl_file_mutex held
1953  */
1954 static int __core_scsi3_write_aptpl_to_file(
1955 	struct se_device *dev,
1956 	unsigned char *buf,
1957 	u32 pr_aptpl_buf_len)
1958 {
1959 	struct t10_wwn *wwn = &dev->t10_wwn;
1960 	struct file *file;
1961 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1962 	char path[512];
1963 	int ret;
1964 
1965 	memset(path, 0, 512);
1966 
1967 	if (strlen(&wwn->unit_serial[0]) >= 512) {
1968 		pr_err("WWN value for struct se_device does not fit"
1969 			" into path buffer\n");
1970 		return -EMSGSIZE;
1971 	}
1972 
1973 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
1974 	file = filp_open(path, flags, 0600);
1975 	if (IS_ERR(file)) {
1976 		pr_err("filp_open(%s) for APTPL metadata"
1977 			" failed\n", path);
1978 		return PTR_ERR(file);
1979 	}
1980 
1981 	if (!pr_aptpl_buf_len)
1982 		pr_aptpl_buf_len = (strlen(&buf[0]) + 1); /* Add extra for NULL */
1983 
1984 	ret = kernel_write(file, buf, pr_aptpl_buf_len, 0);
1985 
1986 	if (ret < 0)
1987 		pr_debug("Error writing APTPL metadata file: %s\n", path);
1988 	fput(file);
1989 
1990 	return ret ? -EIO : 0;
1991 }
1992 
1993 static int
1994 core_scsi3_update_and_write_aptpl(struct se_device *dev, unsigned char *in_buf,
1995 		u32 in_pr_aptpl_buf_len)
1996 {
1997 	unsigned char null_buf[64], *buf;
1998 	u32 pr_aptpl_buf_len;
1999 	int clear_aptpl_metadata = 0;
2000 	int ret;
2001 
2002 	/*
2003 	 * Can be called with a NULL pointer from PROUT service action CLEAR
2004 	 */
2005 	if (!in_buf) {
2006 		memset(null_buf, 0, 64);
2007 		buf = &null_buf[0];
2008 		/*
2009 		 * This will clear the APTPL metadata to:
2010 		 * "No Registrations or Reservations" status
2011 		 */
2012 		pr_aptpl_buf_len = 64;
2013 		clear_aptpl_metadata = 1;
2014 	} else {
2015 		buf = in_buf;
2016 		pr_aptpl_buf_len = in_pr_aptpl_buf_len;
2017 	}
2018 
2019 	ret = core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
2020 				clear_aptpl_metadata);
2021 	if (ret != 0)
2022 		return ret;
2023 
2024 	/*
2025 	 * __core_scsi3_write_aptpl_to_file() will call strlen()
2026 	 * on the passed buf to determine pr_aptpl_buf_len.
2027 	 */
2028 	return __core_scsi3_write_aptpl_to_file(dev, buf, 0);
2029 }
2030 
2031 static sense_reason_t
2032 core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
2033 		int aptpl, int all_tg_pt, int spec_i_pt, int ignore_key)
2034 {
2035 	struct se_session *se_sess = cmd->se_sess;
2036 	struct se_device *dev = cmd->se_dev;
2037 	struct se_dev_entry *se_deve;
2038 	struct se_lun *se_lun = cmd->se_lun;
2039 	struct se_portal_group *se_tpg;
2040 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp, *pr_reg_e;
2041 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2042 	/* Used for APTPL metadata w/ UNREGISTER */
2043 	unsigned char *pr_aptpl_buf = NULL;
2044 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2045 	sense_reason_t ret = TCM_NO_SENSE;
2046 	int pr_holder = 0, type;
2047 
2048 	if (!se_sess || !se_lun) {
2049 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2050 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2051 	}
2052 	se_tpg = se_sess->se_tpg;
2053 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2054 
2055 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2056 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2057 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2058 				PR_REG_ISID_LEN);
2059 		isid_ptr = &isid_buf[0];
2060 	}
2061 	/*
2062 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2063 	 */
2064 	pr_reg_e = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2065 	if (!pr_reg_e) {
2066 		if (res_key) {
2067 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2068 				" for SA REGISTER, returning CONFLICT\n");
2069 			return TCM_RESERVATION_CONFLICT;
2070 		}
2071 		/*
2072 		 * Do nothing but return GOOD status.
2073 		 */
2074 		if (!sa_res_key)
2075 			return 0;
2076 
2077 		if (!spec_i_pt) {
2078 			/*
2079 			 * Perform the Service Action REGISTER on the Initiator
2080 			 * Port Endpoint that the PRO was received from on the
2081 			 * Logical Unit of the SCSI device server.
2082 			 */
2083 			if (core_scsi3_alloc_registration(cmd->se_dev,
2084 					se_sess->se_node_acl, se_deve, isid_ptr,
2085 					sa_res_key, all_tg_pt, aptpl,
2086 					ignore_key, 0)) {
2087 				pr_err("Unable to allocate"
2088 					" struct t10_pr_registration\n");
2089 				return TCM_INVALID_PARAMETER_LIST;
2090 			}
2091 		} else {
2092 			/*
2093 			 * Register both the Initiator port that received
2094 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2095 			 * TransportID from Parameter list and loop through
2096 			 * fabric dependent parameter list while calling
2097 			 * logic from of core_scsi3_alloc_registration() for
2098 			 * each TransportID provided SCSI Initiator Port/Device
2099 			 */
2100 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2101 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2102 			if (ret != 0)
2103 				return ret;
2104 		}
2105 		/*
2106 		 * Nothing left to do for the APTPL=0 case.
2107 		 */
2108 		if (!aptpl) {
2109 			pr_tmpl->pr_aptpl_active = 0;
2110 			core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2111 			pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
2112 					" REGISTER\n");
2113 			return 0;
2114 		}
2115 		/*
2116 		 * Locate the newly allocated local I_T Nexus *pr_reg, and
2117 		 * update the APTPL metadata information using its
2118 		 * preallocated *pr_reg->pr_aptpl_buf.
2119 		 */
2120 		pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev,
2121 				se_sess->se_node_acl, se_sess);
2122 
2123 		if (core_scsi3_update_and_write_aptpl(cmd->se_dev,
2124 				&pr_reg->pr_aptpl_buf[0],
2125 				pr_tmpl->pr_aptpl_buf_len)) {
2126 			pr_tmpl->pr_aptpl_active = 1;
2127 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for REGISTER\n");
2128 		}
2129 
2130 		goto out_put_pr_reg;
2131 	}
2132 
2133 	/*
2134 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2135 	 */
2136 	pr_reg = pr_reg_e;
2137 	type = pr_reg->pr_res_type;
2138 
2139 	if (!ignore_key) {
2140 		if (res_key != pr_reg->pr_res_key) {
2141 			pr_err("SPC-3 PR REGISTER: Received"
2142 				" res_key: 0x%016Lx does not match"
2143 				" existing SA REGISTER res_key:"
2144 				" 0x%016Lx\n", res_key,
2145 				pr_reg->pr_res_key);
2146 			ret = TCM_RESERVATION_CONFLICT;
2147 			goto out_put_pr_reg;
2148 		}
2149 	}
2150 
2151 	if (spec_i_pt) {
2152 		pr_err("SPC-3 PR UNREGISTER: SPEC_I_PT"
2153 			" set while sa_res_key=0\n");
2154 		ret = TCM_INVALID_PARAMETER_LIST;
2155 		goto out_put_pr_reg;
2156 	}
2157 
2158 	/*
2159 	 * An existing ALL_TG_PT=1 registration being released
2160 	 * must also set ALL_TG_PT=1 in the incoming PROUT.
2161 	 */
2162 	if (pr_reg->pr_reg_all_tg_pt && !(all_tg_pt)) {
2163 		pr_err("SPC-3 PR UNREGISTER: ALL_TG_PT=1"
2164 			" registration exists, but ALL_TG_PT=1 bit not"
2165 			" present in received PROUT\n");
2166 		ret = TCM_INVALID_CDB_FIELD;
2167 		goto out_put_pr_reg;
2168 	}
2169 
2170 	/*
2171 	 * Allocate APTPL metadata buffer used for UNREGISTER ops
2172 	 */
2173 	if (aptpl) {
2174 		pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len,
2175 					GFP_KERNEL);
2176 		if (!pr_aptpl_buf) {
2177 			pr_err("Unable to allocate"
2178 				" pr_aptpl_buf\n");
2179 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2180 			goto out_put_pr_reg;
2181 		}
2182 	}
2183 
2184 	/*
2185 	 * sa_res_key=0 Unregister Reservation Key for registered I_T
2186 	 * Nexus sa_res_key=1 Change Reservation Key for registered I_T
2187 	 * Nexus.
2188 	 */
2189 	if (!sa_res_key) {
2190 		pr_holder = core_scsi3_check_implict_release(
2191 				cmd->se_dev, pr_reg);
2192 		if (pr_holder < 0) {
2193 			kfree(pr_aptpl_buf);
2194 			ret = TCM_RESERVATION_CONFLICT;
2195 			goto out_put_pr_reg;
2196 		}
2197 
2198 		spin_lock(&pr_tmpl->registration_lock);
2199 		/*
2200 		 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2201 		 * and matching pr_res_key.
2202 		 */
2203 		if (pr_reg->pr_reg_all_tg_pt) {
2204 			list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2205 					&pr_tmpl->registration_list,
2206 					pr_reg_list) {
2207 
2208 				if (!pr_reg_p->pr_reg_all_tg_pt)
2209 					continue;
2210 				if (pr_reg_p->pr_res_key != res_key)
2211 					continue;
2212 				if (pr_reg == pr_reg_p)
2213 					continue;
2214 				if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2215 					   pr_reg_p->pr_reg_nacl->initiatorname))
2216 					continue;
2217 
2218 				__core_scsi3_free_registration(dev,
2219 						pr_reg_p, NULL, 0);
2220 			}
2221 		}
2222 
2223 		/*
2224 		 * Release the calling I_T Nexus registration now..
2225 		 */
2226 		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);
2227 
2228 		/*
2229 		 * From spc4r17, section 5.7.11.3 Unregistering
2230 		 *
2231 		 * If the persistent reservation is a registrants only
2232 		 * type, the device server shall establish a unit
2233 		 * attention condition for the initiator port associated
2234 		 * with every registered I_T nexus except for the I_T
2235 		 * nexus on which the PERSISTENT RESERVE OUT command was
2236 		 * received, with the additional sense code set to
2237 		 * RESERVATIONS RELEASED.
2238 		 */
2239 		if (pr_holder &&
2240 		   (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||
2241 		    type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {
2242 			list_for_each_entry(pr_reg_p,
2243 					&pr_tmpl->registration_list,
2244 					pr_reg_list) {
2245 
2246 				core_scsi3_ua_allocate(
2247 					pr_reg_p->pr_reg_nacl,
2248 					pr_reg_p->pr_res_mapped_lun,
2249 					0x2A,
2250 					ASCQ_2AH_RESERVATIONS_RELEASED);
2251 			}
2252 		}
2253 		spin_unlock(&pr_tmpl->registration_lock);
2254 
2255 		if (!aptpl) {
2256 			pr_tmpl->pr_aptpl_active = 0;
2257 			core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2258 			pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2259 					" for UNREGISTER\n");
2260 			return 0;
2261 		}
2262 
2263 		if (!core_scsi3_update_and_write_aptpl(dev, &pr_aptpl_buf[0],
2264 				pr_tmpl->pr_aptpl_buf_len)) {
2265 			pr_tmpl->pr_aptpl_active = 1;
2266 			pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2267 					" for UNREGISTER\n");
2268 		}
2269 
2270 		goto out_free_aptpl_buf;
2271 	}
2272 
2273 	/*
2274 	 * Increment PRgeneration counter for struct se_device"
2275 	 * upon a successful REGISTER, see spc4r17 section 6.3.2
2276 	 * READ_KEYS service action.
2277 	 */
2278 	pr_reg->pr_res_generation = core_scsi3_pr_generation(cmd->se_dev);
2279 	pr_reg->pr_res_key = sa_res_key;
2280 	pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2281 		" Key for %s to: 0x%016Lx PRgeneration:"
2282 		" 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2283 		(ignore_key) ? "_AND_IGNORE_EXISTING_KEY" : "",
2284 		pr_reg->pr_reg_nacl->initiatorname,
2285 		pr_reg->pr_res_key, pr_reg->pr_res_generation);
2286 
2287 	if (!aptpl) {
2288 		pr_tmpl->pr_aptpl_active = 0;
2289 		core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2290 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2291 				" for REGISTER\n");
2292 		ret = 0;
2293 		goto out_put_pr_reg;
2294 	}
2295 
2296 	if (!core_scsi3_update_and_write_aptpl(dev, &pr_aptpl_buf[0],
2297 						pr_tmpl->pr_aptpl_buf_len)) {
2298 		pr_tmpl->pr_aptpl_active = 1;
2299 		pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2300 			" for REGISTER\n");
2301 	}
2302 
2303 out_free_aptpl_buf:
2304 	kfree(pr_aptpl_buf);
2305 	ret = 0;
2306 out_put_pr_reg:
2307 	core_scsi3_put_pr_reg(pr_reg);
2308 	return ret;
2309 }
2310 
2311 unsigned char *core_scsi3_pr_dump_type(int type)
2312 {
2313 	switch (type) {
2314 	case PR_TYPE_WRITE_EXCLUSIVE:
2315 		return "Write Exclusive Access";
2316 	case PR_TYPE_EXCLUSIVE_ACCESS:
2317 		return "Exclusive Access";
2318 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2319 		return "Write Exclusive Access, Registrants Only";
2320 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2321 		return "Exclusive Access, Registrants Only";
2322 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2323 		return "Write Exclusive Access, All Registrants";
2324 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2325 		return "Exclusive Access, All Registrants";
2326 	default:
2327 		break;
2328 	}
2329 
2330 	return "Unknown SPC-3 PR Type";
2331 }
2332 
2333 static sense_reason_t
2334 core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
2335 {
2336 	struct se_device *dev = cmd->se_dev;
2337 	struct se_session *se_sess = cmd->se_sess;
2338 	struct se_lun *se_lun = cmd->se_lun;
2339 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2340 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2341 	char i_buf[PR_REG_ISID_ID_LEN];
2342 	sense_reason_t ret;
2343 	int prf_isid;
2344 
2345 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2346 
2347 	if (!se_sess || !se_lun) {
2348 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2349 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2350 	}
2351 	/*
2352 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2353 	 */
2354 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2355 				se_sess);
2356 	if (!pr_reg) {
2357 		pr_err("SPC-3 PR: Unable to locate"
2358 			" PR_REGISTERED *pr_reg for RESERVE\n");
2359 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2360 	}
2361 	/*
2362 	 * From spc4r17 Section 5.7.9: Reserving:
2363 	 *
2364 	 * An application client creates a persistent reservation by issuing
2365 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2366 	 * a registered I_T nexus with the following parameters:
2367 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2368 	 * 	 registered with the logical unit for the I_T nexus; and
2369 	 */
2370 	if (res_key != pr_reg->pr_res_key) {
2371 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2372 			" does not match existing SA REGISTER res_key:"
2373 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2374 		ret = TCM_RESERVATION_CONFLICT;
2375 		goto out_put_pr_reg;
2376 	}
2377 	/*
2378 	 * From spc4r17 Section 5.7.9: Reserving:
2379 	 *
2380 	 * From above:
2381 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2382 	 *     being created.
2383 	 *
2384 	 * Only one persistent reservation is allowed at a time per logical unit
2385 	 * and that persistent reservation has a scope of LU_SCOPE.
2386 	 */
2387 	if (scope != PR_SCOPE_LU_SCOPE) {
2388 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2389 		ret = TCM_INVALID_PARAMETER_LIST;
2390 		goto out_put_pr_reg;
2391 	}
2392 	/*
2393 	 * See if we have an existing PR reservation holder pointer at
2394 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2395 	 * *pr_res_holder.
2396 	 */
2397 	spin_lock(&dev->dev_reservation_lock);
2398 	pr_res_holder = dev->dev_pr_res_holder;
2399 	if (pr_res_holder) {
2400 		/*
2401 		 * From spc4r17 Section 5.7.9: Reserving:
2402 		 *
2403 		 * If the device server receives a PERSISTENT RESERVE OUT
2404 		 * command from an I_T nexus other than a persistent reservation
2405 		 * holder (see 5.7.10) that attempts to create a persistent
2406 		 * reservation when a persistent reservation already exists for
2407 		 * the logical unit, then the command shall be completed with
2408 		 * RESERVATION CONFLICT status.
2409 		 */
2410 		if (pr_res_holder != pr_reg) {
2411 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2412 			pr_err("SPC-3 PR: Attempted RESERVE from"
2413 				" [%s]: %s while reservation already held by"
2414 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2415 				cmd->se_tfo->get_fabric_name(),
2416 				se_sess->se_node_acl->initiatorname,
2417 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2418 				pr_res_holder->pr_reg_nacl->initiatorname);
2419 
2420 			spin_unlock(&dev->dev_reservation_lock);
2421 			ret = TCM_RESERVATION_CONFLICT;
2422 			goto out_put_pr_reg;
2423 		}
2424 		/*
2425 		 * From spc4r17 Section 5.7.9: Reserving:
2426 		 *
2427 		 * If a persistent reservation holder attempts to modify the
2428 		 * type or scope of an existing persistent reservation, the
2429 		 * command shall be completed with RESERVATION CONFLICT status.
2430 		 */
2431 		if ((pr_res_holder->pr_res_type != type) ||
2432 		    (pr_res_holder->pr_res_scope != scope)) {
2433 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2434 			pr_err("SPC-3 PR: Attempted RESERVE from"
2435 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2436 				" while reservation already held by [%s]: %s,"
2437 				" returning RESERVATION_CONFLICT\n",
2438 				cmd->se_tfo->get_fabric_name(),
2439 				se_sess->se_node_acl->initiatorname,
2440 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2441 				pr_res_holder->pr_reg_nacl->initiatorname);
2442 
2443 			spin_unlock(&dev->dev_reservation_lock);
2444 			ret = TCM_RESERVATION_CONFLICT;
2445 			goto out_put_pr_reg;
2446 		}
2447 		/*
2448 		 * From spc4r17 Section 5.7.9: Reserving:
2449 		 *
2450 		 * If the device server receives a PERSISTENT RESERVE OUT
2451 		 * command with RESERVE service action where the TYPE field and
2452 		 * the SCOPE field contain the same values as the existing type
2453 		 * and scope from a persistent reservation holder, it shall not
2454 		 * make any change to the existing persistent reservation and
2455 		 * shall completethe command with GOOD status.
2456 		 */
2457 		spin_unlock(&dev->dev_reservation_lock);
2458 		ret = 0;
2459 		goto out_put_pr_reg;
2460 	}
2461 	/*
2462 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2463 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2464 	 */
2465 	pr_reg->pr_res_scope = scope;
2466 	pr_reg->pr_res_type = type;
2467 	pr_reg->pr_res_holder = 1;
2468 	dev->dev_pr_res_holder = pr_reg;
2469 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2470 				PR_REG_ISID_ID_LEN);
2471 
2472 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2473 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2474 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2475 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2476 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2477 			cmd->se_tfo->get_fabric_name(),
2478 			se_sess->se_node_acl->initiatorname,
2479 			(prf_isid) ? &i_buf[0] : "");
2480 	spin_unlock(&dev->dev_reservation_lock);
2481 
2482 	if (pr_tmpl->pr_aptpl_active) {
2483 		if (!core_scsi3_update_and_write_aptpl(cmd->se_dev,
2484 				&pr_reg->pr_aptpl_buf[0],
2485 				pr_tmpl->pr_aptpl_buf_len)) {
2486 			pr_debug("SPC-3 PR: Updated APTPL metadata"
2487 					" for RESERVE\n");
2488 		}
2489 	}
2490 
2491 	ret = 0;
2492 out_put_pr_reg:
2493 	core_scsi3_put_pr_reg(pr_reg);
2494 	return ret;
2495 }
2496 
2497 static sense_reason_t
2498 core_scsi3_emulate_pro_reserve(struct se_cmd *cmd, int type, int scope,
2499 		u64 res_key)
2500 {
2501 	switch (type) {
2502 	case PR_TYPE_WRITE_EXCLUSIVE:
2503 	case PR_TYPE_EXCLUSIVE_ACCESS:
2504 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2505 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2506 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2507 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2508 		return core_scsi3_pro_reserve(cmd, type, scope, res_key);
2509 	default:
2510 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2511 			" 0x%02x\n", type);
2512 		return TCM_INVALID_CDB_FIELD;
2513 	}
2514 }
2515 
2516 /*
2517  * Called with struct se_device->dev_reservation_lock held.
2518  */
2519 static void __core_scsi3_complete_pro_release(
2520 	struct se_device *dev,
2521 	struct se_node_acl *se_nacl,
2522 	struct t10_pr_registration *pr_reg,
2523 	int explict)
2524 {
2525 	struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2526 	char i_buf[PR_REG_ISID_ID_LEN];
2527 	int prf_isid;
2528 
2529 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2530 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2531 				PR_REG_ISID_ID_LEN);
2532 	/*
2533 	 * Go ahead and release the current PR reservation holder.
2534 	 */
2535 	dev->dev_pr_res_holder = NULL;
2536 
2537 	pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2538 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2539 		tfo->get_fabric_name(), (explict) ? "explict" : "implict",
2540 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
2541 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2542 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2543 		tfo->get_fabric_name(), se_nacl->initiatorname,
2544 		(prf_isid) ? &i_buf[0] : "");
2545 	/*
2546 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2547 	 */
2548 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2549 }
2550 
2551 static sense_reason_t
2552 core_scsi3_emulate_pro_release(struct se_cmd *cmd, int type, int scope,
2553 		u64 res_key)
2554 {
2555 	struct se_device *dev = cmd->se_dev;
2556 	struct se_session *se_sess = cmd->se_sess;
2557 	struct se_lun *se_lun = cmd->se_lun;
2558 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2559 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2560 	int all_reg = 0;
2561 	sense_reason_t ret = 0;
2562 
2563 	if (!se_sess || !se_lun) {
2564 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2565 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2566 	}
2567 	/*
2568 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2569 	 */
2570 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2571 	if (!pr_reg) {
2572 		pr_err("SPC-3 PR: Unable to locate"
2573 			" PR_REGISTERED *pr_reg for RELEASE\n");
2574 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2575 	}
2576 	/*
2577 	 * From spc4r17 Section 5.7.11.2 Releasing:
2578 	 *
2579 	 * If there is no persistent reservation or in response to a persistent
2580 	 * reservation release request from a registered I_T nexus that is not a
2581 	 * persistent reservation holder (see 5.7.10), the device server shall
2582 	 * do the following:
2583 	 *
2584 	 *     a) Not release the persistent reservation, if any;
2585 	 *     b) Not remove any registrations; and
2586 	 *     c) Complete the command with GOOD status.
2587 	 */
2588 	spin_lock(&dev->dev_reservation_lock);
2589 	pr_res_holder = dev->dev_pr_res_holder;
2590 	if (!pr_res_holder) {
2591 		/*
2592 		 * No persistent reservation, return GOOD status.
2593 		 */
2594 		spin_unlock(&dev->dev_reservation_lock);
2595 		goto out_put_pr_reg;
2596 	}
2597 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2598 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
2599 		all_reg = 1;
2600 
2601 	if ((all_reg == 0) && (pr_res_holder != pr_reg)) {
2602 		/*
2603 		 * Non 'All Registrants' PR Type cases..
2604 		 * Release request from a registered I_T nexus that is not a
2605 		 * persistent reservation holder. return GOOD status.
2606 		 */
2607 		spin_unlock(&dev->dev_reservation_lock);
2608 		goto out_put_pr_reg;
2609 	}
2610 
2611 	/*
2612 	 * From spc4r17 Section 5.7.11.2 Releasing:
2613 	 *
2614 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2615 	 * release a persistent reservation.
2616 	 *
2617 	 * An application client releases the persistent reservation by issuing
2618 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2619 	 * an I_T nexus that is a persistent reservation holder with the
2620 	 * following parameters:
2621 	 *
2622 	 *     a) RESERVATION KEY field set to the value of the reservation key
2623 	 *	  that is registered with the logical unit for the I_T nexus;
2624 	 */
2625 	if (res_key != pr_reg->pr_res_key) {
2626 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2627 			" does not match existing SA REGISTER res_key:"
2628 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2629 		spin_unlock(&dev->dev_reservation_lock);
2630 		ret = TCM_RESERVATION_CONFLICT;
2631 		goto out_put_pr_reg;
2632 	}
2633 	/*
2634 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2635 	 *
2636 	 * b) TYPE field and SCOPE field set to match the persistent
2637 	 *    reservation being released.
2638 	 */
2639 	if ((pr_res_holder->pr_res_type != type) ||
2640 	    (pr_res_holder->pr_res_scope != scope)) {
2641 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2642 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2643 			" reservation from [%s]: %s with different TYPE "
2644 			"and/or SCOPE  while reservation already held by"
2645 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2646 			cmd->se_tfo->get_fabric_name(),
2647 			se_sess->se_node_acl->initiatorname,
2648 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2649 			pr_res_holder->pr_reg_nacl->initiatorname);
2650 
2651 		spin_unlock(&dev->dev_reservation_lock);
2652 		ret = TCM_RESERVATION_CONFLICT;
2653 		goto out_put_pr_reg;
2654 	}
2655 	/*
2656 	 * In response to a persistent reservation release request from the
2657 	 * persistent reservation holder the device server shall perform a
2658 	 * release by doing the following as an uninterrupted series of actions:
2659 	 * a) Release the persistent reservation;
2660 	 * b) Not remove any registration(s);
2661 	 * c) If the released persistent reservation is a registrants only type
2662 	 * or all registrants type persistent reservation,
2663 	 *    the device server shall establish a unit attention condition for
2664 	 *    the initiator port associated with every regis-
2665 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2666 	 *    RESERVE OUT command with RELEASE service action was received,
2667 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2668 	 * d) If the persistent reservation is of any other type, the device
2669 	 *    server shall not establish a unit attention condition.
2670 	 */
2671 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2672 			pr_reg, 1);
2673 
2674 	spin_unlock(&dev->dev_reservation_lock);
2675 
2676 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2677 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2678 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2679 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2680 		/*
2681 		 * If no UNIT ATTENTION conditions will be established for
2682 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2683 		 * go ahead and check for APTPL=1 update+write below
2684 		 */
2685 		goto write_aptpl;
2686 	}
2687 
2688 	spin_lock(&pr_tmpl->registration_lock);
2689 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2690 			pr_reg_list) {
2691 		/*
2692 		 * Do not establish a UNIT ATTENTION condition
2693 		 * for the calling I_T Nexus
2694 		 */
2695 		if (pr_reg_p == pr_reg)
2696 			continue;
2697 
2698 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2699 				pr_reg_p->pr_res_mapped_lun,
2700 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2701 	}
2702 	spin_unlock(&pr_tmpl->registration_lock);
2703 
2704 write_aptpl:
2705 	if (pr_tmpl->pr_aptpl_active) {
2706 		if (!core_scsi3_update_and_write_aptpl(cmd->se_dev,
2707 			&pr_reg->pr_aptpl_buf[0], pr_tmpl->pr_aptpl_buf_len)) {
2708 			pr_debug("SPC-3 PR: Updated APTPL metadata for RELEASE\n");
2709 		}
2710 	}
2711 out_put_pr_reg:
2712 	core_scsi3_put_pr_reg(pr_reg);
2713 	return ret;
2714 }
2715 
2716 static sense_reason_t
2717 core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
2718 {
2719 	struct se_device *dev = cmd->se_dev;
2720 	struct se_node_acl *pr_reg_nacl;
2721 	struct se_session *se_sess = cmd->se_sess;
2722 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2723 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2724 	u32 pr_res_mapped_lun = 0;
2725 	int calling_it_nexus = 0;
2726 	/*
2727 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2728 	 */
2729 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2730 			se_sess->se_node_acl, se_sess);
2731 	if (!pr_reg_n) {
2732 		pr_err("SPC-3 PR: Unable to locate"
2733 			" PR_REGISTERED *pr_reg for CLEAR\n");
2734 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2735 	}
2736 	/*
2737 	 * From spc4r17 section 5.7.11.6, Clearing:
2738 	 *
2739 	 * Any application client may release the persistent reservation and
2740 	 * remove all registrations from a device server by issuing a
2741 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2742 	 * registered I_T nexus with the following parameter:
2743 	 *
2744 	 *	a) RESERVATION KEY field set to the value of the reservation key
2745 	 * 	   that is registered with the logical unit for the I_T nexus.
2746 	 */
2747 	if (res_key != pr_reg_n->pr_res_key) {
2748 		pr_err("SPC-3 PR REGISTER: Received"
2749 			" res_key: 0x%016Lx does not match"
2750 			" existing SA REGISTER res_key:"
2751 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2752 		core_scsi3_put_pr_reg(pr_reg_n);
2753 		return TCM_RESERVATION_CONFLICT;
2754 	}
2755 	/*
2756 	 * a) Release the persistent reservation, if any;
2757 	 */
2758 	spin_lock(&dev->dev_reservation_lock);
2759 	pr_res_holder = dev->dev_pr_res_holder;
2760 	if (pr_res_holder) {
2761 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2762 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2763 			pr_res_holder, 0);
2764 	}
2765 	spin_unlock(&dev->dev_reservation_lock);
2766 	/*
2767 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2768 	 */
2769 	spin_lock(&pr_tmpl->registration_lock);
2770 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2771 			&pr_tmpl->registration_list, pr_reg_list) {
2772 
2773 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2774 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2775 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2776 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2777 					calling_it_nexus);
2778 		/*
2779 		 * e) Establish a unit attention condition for the initiator
2780 		 *    port associated with every registered I_T nexus other
2781 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2782 		 *    command with CLEAR service action was received, with the
2783 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2784 		 */
2785 		if (!calling_it_nexus)
2786 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2787 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2788 	}
2789 	spin_unlock(&pr_tmpl->registration_lock);
2790 
2791 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2792 		cmd->se_tfo->get_fabric_name());
2793 
2794 	if (pr_tmpl->pr_aptpl_active) {
2795 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2796 		pr_debug("SPC-3 PR: Updated APTPL metadata"
2797 				" for CLEAR\n");
2798 	}
2799 
2800 	core_scsi3_pr_generation(dev);
2801 	return 0;
2802 }
2803 
2804 /*
2805  * Called with struct se_device->dev_reservation_lock held.
2806  */
2807 static void __core_scsi3_complete_pro_preempt(
2808 	struct se_device *dev,
2809 	struct t10_pr_registration *pr_reg,
2810 	struct list_head *preempt_and_abort_list,
2811 	int type,
2812 	int scope,
2813 	int abort)
2814 {
2815 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2816 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2817 	char i_buf[PR_REG_ISID_ID_LEN];
2818 	int prf_isid;
2819 
2820 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2821 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2822 				PR_REG_ISID_ID_LEN);
2823 	/*
2824 	 * Do an implict RELEASE of the existing reservation.
2825 	 */
2826 	if (dev->dev_pr_res_holder)
2827 		__core_scsi3_complete_pro_release(dev, nacl,
2828 				dev->dev_pr_res_holder, 0);
2829 
2830 	dev->dev_pr_res_holder = pr_reg;
2831 	pr_reg->pr_res_holder = 1;
2832 	pr_reg->pr_res_type = type;
2833 	pr_reg->pr_res_scope = scope;
2834 
2835 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2836 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2837 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2838 		core_scsi3_pr_dump_type(type),
2839 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2840 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2841 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2842 		nacl->initiatorname, (prf_isid) ? &i_buf[0] : "");
2843 	/*
2844 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2845 	 * struct t10_pr_registration to the list that will be compared
2846 	 * against received CDBs..
2847 	 */
2848 	if (preempt_and_abort_list)
2849 		list_add_tail(&pr_reg->pr_reg_abort_list,
2850 				preempt_and_abort_list);
2851 }
2852 
2853 static void core_scsi3_release_preempt_and_abort(
2854 	struct list_head *preempt_and_abort_list,
2855 	struct t10_pr_registration *pr_reg_holder)
2856 {
2857 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2858 
2859 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2860 				pr_reg_abort_list) {
2861 
2862 		list_del(&pr_reg->pr_reg_abort_list);
2863 		if (pr_reg_holder == pr_reg)
2864 			continue;
2865 		if (pr_reg->pr_res_holder) {
2866 			pr_warn("pr_reg->pr_res_holder still set\n");
2867 			continue;
2868 		}
2869 
2870 		pr_reg->pr_reg_deve = NULL;
2871 		pr_reg->pr_reg_nacl = NULL;
2872 		kfree(pr_reg->pr_aptpl_buf);
2873 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2874 	}
2875 }
2876 
2877 static sense_reason_t
2878 core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
2879 		u64 sa_res_key, int abort)
2880 {
2881 	struct se_device *dev = cmd->se_dev;
2882 	struct se_node_acl *pr_reg_nacl;
2883 	struct se_session *se_sess = cmd->se_sess;
2884 	LIST_HEAD(preempt_and_abort_list);
2885 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2886 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
2887 	u32 pr_res_mapped_lun = 0;
2888 	int all_reg = 0, calling_it_nexus = 0, released_regs = 0;
2889 	int prh_type = 0, prh_scope = 0;
2890 
2891 	if (!se_sess)
2892 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2893 
2894 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2895 				se_sess);
2896 	if (!pr_reg_n) {
2897 		pr_err("SPC-3 PR: Unable to locate"
2898 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2899 			(abort) ? "_AND_ABORT" : "");
2900 		return TCM_RESERVATION_CONFLICT;
2901 	}
2902 	if (pr_reg_n->pr_res_key != res_key) {
2903 		core_scsi3_put_pr_reg(pr_reg_n);
2904 		return TCM_RESERVATION_CONFLICT;
2905 	}
2906 	if (scope != PR_SCOPE_LU_SCOPE) {
2907 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2908 		core_scsi3_put_pr_reg(pr_reg_n);
2909 		return TCM_INVALID_PARAMETER_LIST;
2910 	}
2911 
2912 	spin_lock(&dev->dev_reservation_lock);
2913 	pr_res_holder = dev->dev_pr_res_holder;
2914 	if (pr_res_holder &&
2915 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2916 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
2917 		all_reg = 1;
2918 
2919 	if (!all_reg && !sa_res_key) {
2920 		spin_unlock(&dev->dev_reservation_lock);
2921 		core_scsi3_put_pr_reg(pr_reg_n);
2922 		return TCM_INVALID_PARAMETER_LIST;
2923 	}
2924 	/*
2925 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
2926 	 *
2927 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
2928 	 * persistent reservation holder or there is no persistent reservation
2929 	 * holder (i.e., there is no persistent reservation), then the device
2930 	 * server shall perform a preempt by doing the following in an
2931 	 * uninterrupted series of actions. (See below..)
2932 	 */
2933 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
2934 		/*
2935 		 * No existing or SA Reservation Key matching reservations..
2936 		 *
2937 		 * PROUT SA PREEMPT with All Registrant type reservations are
2938 		 * allowed to be processed without a matching SA Reservation Key
2939 		 */
2940 		spin_lock(&pr_tmpl->registration_lock);
2941 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2942 				&pr_tmpl->registration_list, pr_reg_list) {
2943 			/*
2944 			 * Removing of registrations in non all registrants
2945 			 * type reservations without a matching SA reservation
2946 			 * key.
2947 			 *
2948 			 * a) Remove the registrations for all I_T nexuses
2949 			 *    specified by the SERVICE ACTION RESERVATION KEY
2950 			 *    field;
2951 			 * b) Ignore the contents of the SCOPE and TYPE fields;
2952 			 * c) Process tasks as defined in 5.7.1; and
2953 			 * d) Establish a unit attention condition for the
2954 			 *    initiator port associated with every I_T nexus
2955 			 *    that lost its registration other than the I_T
2956 			 *    nexus on which the PERSISTENT RESERVE OUT command
2957 			 *    was received, with the additional sense code set
2958 			 *    to REGISTRATIONS PREEMPTED.
2959 			 */
2960 			if (!all_reg) {
2961 				if (pr_reg->pr_res_key != sa_res_key)
2962 					continue;
2963 
2964 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2965 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2966 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2967 				__core_scsi3_free_registration(dev, pr_reg,
2968 					(abort) ? &preempt_and_abort_list :
2969 						NULL, calling_it_nexus);
2970 				released_regs++;
2971 			} else {
2972 				/*
2973 				 * Case for any existing all registrants type
2974 				 * reservation, follow logic in spc4r17 section
2975 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
2976 				 *
2977 				 * For a ZERO SA Reservation key, release
2978 				 * all other registrations and do an implict
2979 				 * release of active persistent reservation.
2980 				 *
2981 				 * For a non-ZERO SA Reservation key, only
2982 				 * release the matching reservation key from
2983 				 * registrations.
2984 				 */
2985 				if ((sa_res_key) &&
2986 				     (pr_reg->pr_res_key != sa_res_key))
2987 					continue;
2988 
2989 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2990 				if (calling_it_nexus)
2991 					continue;
2992 
2993 				pr_reg_nacl = pr_reg->pr_reg_nacl;
2994 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2995 				__core_scsi3_free_registration(dev, pr_reg,
2996 					(abort) ? &preempt_and_abort_list :
2997 						NULL, 0);
2998 				released_regs++;
2999 			}
3000 			if (!calling_it_nexus)
3001 				core_scsi3_ua_allocate(pr_reg_nacl,
3002 					pr_res_mapped_lun, 0x2A,
3003 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3004 		}
3005 		spin_unlock(&pr_tmpl->registration_lock);
3006 		/*
3007 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
3008 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
3009 		 * RESERVATION KEY field to a value that does not match any
3010 		 * registered reservation key, then the device server shall
3011 		 * complete the command with RESERVATION CONFLICT status.
3012 		 */
3013 		if (!released_regs) {
3014 			spin_unlock(&dev->dev_reservation_lock);
3015 			core_scsi3_put_pr_reg(pr_reg_n);
3016 			return TCM_RESERVATION_CONFLICT;
3017 		}
3018 		/*
3019 		 * For an existing all registrants type reservation
3020 		 * with a zero SA rservation key, preempt the existing
3021 		 * reservation with the new PR type and scope.
3022 		 */
3023 		if (pr_res_holder && all_reg && !(sa_res_key)) {
3024 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3025 				(abort) ? &preempt_and_abort_list : NULL,
3026 				type, scope, abort);
3027 
3028 			if (abort)
3029 				core_scsi3_release_preempt_and_abort(
3030 					&preempt_and_abort_list, pr_reg_n);
3031 		}
3032 		spin_unlock(&dev->dev_reservation_lock);
3033 
3034 		if (pr_tmpl->pr_aptpl_active) {
3035 			if (!core_scsi3_update_and_write_aptpl(cmd->se_dev,
3036 					&pr_reg_n->pr_aptpl_buf[0],
3037 					pr_tmpl->pr_aptpl_buf_len)) {
3038 				pr_debug("SPC-3 PR: Updated APTPL"
3039 					" metadata for  PREEMPT%s\n", (abort) ?
3040 					"_AND_ABORT" : "");
3041 			}
3042 		}
3043 
3044 		core_scsi3_put_pr_reg(pr_reg_n);
3045 		core_scsi3_pr_generation(cmd->se_dev);
3046 		return 0;
3047 	}
3048 	/*
3049 	 * The PREEMPTing SA reservation key matches that of the
3050 	 * existing persistent reservation, first, we check if
3051 	 * we are preempting our own reservation.
3052 	 * From spc4r17, section 5.7.11.4.3 Preempting
3053 	 * persistent reservations and registration handling
3054 	 *
3055 	 * If an all registrants persistent reservation is not
3056 	 * present, it is not an error for the persistent
3057 	 * reservation holder to preempt itself (i.e., a
3058 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3059 	 * or a PREEMPT AND ABORT service action with the
3060 	 * SERVICE ACTION RESERVATION KEY value equal to the
3061 	 * persistent reservation holder's reservation key that
3062 	 * is received from the persistent reservation holder).
3063 	 * In that case, the device server shall establish the
3064 	 * new persistent reservation and maintain the
3065 	 * registration.
3066 	 */
3067 	prh_type = pr_res_holder->pr_res_type;
3068 	prh_scope = pr_res_holder->pr_res_scope;
3069 	/*
3070 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3071 	 * persistent reservation holder (see 5.7.10), the device
3072 	 * server shall perform a preempt by doing the following as
3073 	 * an uninterrupted series of actions:
3074 	 *
3075 	 * a) Release the persistent reservation for the holder
3076 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3077 	 */
3078 	if (pr_reg_n != pr_res_holder)
3079 		__core_scsi3_complete_pro_release(dev,
3080 				pr_res_holder->pr_reg_nacl,
3081 				dev->dev_pr_res_holder, 0);
3082 	/*
3083 	 * b) Remove the registrations for all I_T nexuses identified
3084 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3085 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3086 	 *    OUT command. If an all registrants persistent reservation
3087 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3088 	 *    is set to zero, then all registrations shall be removed
3089 	 *    except for that of the I_T nexus that is being used for
3090 	 *    the PERSISTENT RESERVE OUT command;
3091 	 */
3092 	spin_lock(&pr_tmpl->registration_lock);
3093 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3094 			&pr_tmpl->registration_list, pr_reg_list) {
3095 
3096 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3097 		if (calling_it_nexus)
3098 			continue;
3099 
3100 		if (pr_reg->pr_res_key != sa_res_key)
3101 			continue;
3102 
3103 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3104 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3105 		__core_scsi3_free_registration(dev, pr_reg,
3106 				(abort) ? &preempt_and_abort_list : NULL,
3107 				calling_it_nexus);
3108 		/*
3109 		 * e) Establish a unit attention condition for the initiator
3110 		 *    port associated with every I_T nexus that lost its
3111 		 *    persistent reservation and/or registration, with the
3112 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3113 		 */
3114 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3115 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3116 	}
3117 	spin_unlock(&pr_tmpl->registration_lock);
3118 	/*
3119 	 * c) Establish a persistent reservation for the preempting
3120 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3121 	 */
3122 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3123 			(abort) ? &preempt_and_abort_list : NULL,
3124 			type, scope, abort);
3125 	/*
3126 	 * d) Process tasks as defined in 5.7.1;
3127 	 * e) See above..
3128 	 * f) If the type or scope has changed, then for every I_T nexus
3129 	 *    whose reservation key was not removed, except for the I_T
3130 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3131 	 *    received, the device server shall establish a unit
3132 	 *    attention condition for the initiator port associated with
3133 	 *    that I_T nexus, with the additional sense code set to
3134 	 *    RESERVATIONS RELEASED. If the type or scope have not
3135 	 *    changed, then no unit attention condition(s) shall be
3136 	 *    established for this reason.
3137 	 */
3138 	if ((prh_type != type) || (prh_scope != scope)) {
3139 		spin_lock(&pr_tmpl->registration_lock);
3140 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3141 				&pr_tmpl->registration_list, pr_reg_list) {
3142 
3143 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3144 			if (calling_it_nexus)
3145 				continue;
3146 
3147 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
3148 					pr_reg->pr_res_mapped_lun, 0x2A,
3149 					ASCQ_2AH_RESERVATIONS_RELEASED);
3150 		}
3151 		spin_unlock(&pr_tmpl->registration_lock);
3152 	}
3153 	spin_unlock(&dev->dev_reservation_lock);
3154 	/*
3155 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3156 	 * All received CDBs for the matching existing reservation and
3157 	 * registrations undergo ABORT_TASK logic.
3158 	 *
3159 	 * From there, core_scsi3_release_preempt_and_abort() will
3160 	 * release every registration in the list (which have already
3161 	 * been removed from the primary pr_reg list), except the
3162 	 * new persistent reservation holder, the calling Initiator Port.
3163 	 */
3164 	if (abort) {
3165 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3166 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3167 						pr_reg_n);
3168 	}
3169 
3170 	if (pr_tmpl->pr_aptpl_active) {
3171 		if (!core_scsi3_update_and_write_aptpl(cmd->se_dev,
3172 				&pr_reg_n->pr_aptpl_buf[0],
3173 				pr_tmpl->pr_aptpl_buf_len)) {
3174 			pr_debug("SPC-3 PR: Updated APTPL metadata for PREEMPT"
3175 				"%s\n", abort ? "_AND_ABORT" : "");
3176 		}
3177 	}
3178 
3179 	core_scsi3_put_pr_reg(pr_reg_n);
3180 	core_scsi3_pr_generation(cmd->se_dev);
3181 	return 0;
3182 }
3183 
3184 static sense_reason_t
3185 core_scsi3_emulate_pro_preempt(struct se_cmd *cmd, int type, int scope,
3186 		u64 res_key, u64 sa_res_key, int abort)
3187 {
3188 	switch (type) {
3189 	case PR_TYPE_WRITE_EXCLUSIVE:
3190 	case PR_TYPE_EXCLUSIVE_ACCESS:
3191 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3192 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3193 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3194 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3195 		return core_scsi3_pro_preempt(cmd, type, scope, res_key,
3196 					      sa_res_key, abort);
3197 	default:
3198 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3199 			" Type: 0x%02x\n", (abort) ? "_AND_ABORT" : "", type);
3200 		return TCM_INVALID_CDB_FIELD;
3201 	}
3202 }
3203 
3204 
3205 static sense_reason_t
3206 core_scsi3_emulate_pro_register_and_move(struct se_cmd *cmd, u64 res_key,
3207 		u64 sa_res_key, int aptpl, int unreg)
3208 {
3209 	struct se_session *se_sess = cmd->se_sess;
3210 	struct se_device *dev = cmd->se_dev;
3211 	struct se_dev_entry *dest_se_deve = NULL;
3212 	struct se_lun *se_lun = cmd->se_lun;
3213 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3214 	struct se_port *se_port;
3215 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3216 	struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3217 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3218 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3219 	unsigned char *buf;
3220 	unsigned char *initiator_str;
3221 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
3222 	u32 tid_len, tmp_tid_len;
3223 	int new_reg = 0, type, scope, matching_iname, prf_isid;
3224 	sense_reason_t ret;
3225 	unsigned short rtpi;
3226 	unsigned char proto_ident;
3227 
3228 	if (!se_sess || !se_lun) {
3229 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3230 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3231 	}
3232 
3233 	memset(dest_iport, 0, 64);
3234 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3235 	se_tpg = se_sess->se_tpg;
3236 	tf_ops = se_tpg->se_tpg_tfo;
3237 	/*
3238 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3239 	 *	Register behaviors for a REGISTER AND MOVE service action
3240 	 *
3241 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3242 	 */
3243 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3244 				se_sess);
3245 	if (!pr_reg) {
3246 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3247 			" *pr_reg for REGISTER_AND_MOVE\n");
3248 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3249 	}
3250 	/*
3251 	 * The provided reservation key much match the existing reservation key
3252 	 * provided during this initiator's I_T nexus registration.
3253 	 */
3254 	if (res_key != pr_reg->pr_res_key) {
3255 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3256 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3257 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3258 		ret = TCM_RESERVATION_CONFLICT;
3259 		goto out_put_pr_reg;
3260 	}
3261 	/*
3262 	 * The service active reservation key needs to be non zero
3263 	 */
3264 	if (!sa_res_key) {
3265 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3266 			" sa_res_key\n");
3267 		ret = TCM_INVALID_PARAMETER_LIST;
3268 		goto out_put_pr_reg;
3269 	}
3270 
3271 	/*
3272 	 * Determine the Relative Target Port Identifier where the reservation
3273 	 * will be moved to for the TransportID containing SCSI initiator WWN
3274 	 * information.
3275 	 */
3276 	buf = transport_kmap_data_sg(cmd);
3277 	if (!buf) {
3278 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3279 		goto out_put_pr_reg;
3280 	}
3281 
3282 	rtpi = (buf[18] & 0xff) << 8;
3283 	rtpi |= buf[19] & 0xff;
3284 	tid_len = (buf[20] & 0xff) << 24;
3285 	tid_len |= (buf[21] & 0xff) << 16;
3286 	tid_len |= (buf[22] & 0xff) << 8;
3287 	tid_len |= buf[23] & 0xff;
3288 	transport_kunmap_data_sg(cmd);
3289 	buf = NULL;
3290 
3291 	if ((tid_len + 24) != cmd->data_length) {
3292 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3293 			" does not equal CDB data_length: %u\n", tid_len,
3294 			cmd->data_length);
3295 		ret = TCM_INVALID_PARAMETER_LIST;
3296 		goto out_put_pr_reg;
3297 	}
3298 
3299 	spin_lock(&dev->se_port_lock);
3300 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3301 		if (se_port->sep_rtpi != rtpi)
3302 			continue;
3303 		dest_se_tpg = se_port->sep_tpg;
3304 		if (!dest_se_tpg)
3305 			continue;
3306 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3307 		if (!dest_tf_ops)
3308 			continue;
3309 
3310 		atomic_inc(&dest_se_tpg->tpg_pr_ref_count);
3311 		smp_mb__after_atomic_inc();
3312 		spin_unlock(&dev->se_port_lock);
3313 
3314 		if (core_scsi3_tpg_depend_item(dest_se_tpg)) {
3315 			pr_err("core_scsi3_tpg_depend_item() failed"
3316 				" for dest_se_tpg\n");
3317 			atomic_dec(&dest_se_tpg->tpg_pr_ref_count);
3318 			smp_mb__after_atomic_dec();
3319 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3320 			goto out_put_pr_reg;
3321 		}
3322 
3323 		spin_lock(&dev->se_port_lock);
3324 		break;
3325 	}
3326 	spin_unlock(&dev->se_port_lock);
3327 
3328 	if (!dest_se_tpg || !dest_tf_ops) {
3329 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3330 			" fabric ops from Relative Target Port Identifier:"
3331 			" %hu\n", rtpi);
3332 		ret = TCM_INVALID_PARAMETER_LIST;
3333 		goto out_put_pr_reg;
3334 	}
3335 
3336 	buf = transport_kmap_data_sg(cmd);
3337 	if (!buf) {
3338 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3339 		goto out_put_pr_reg;
3340 	}
3341 	proto_ident = (buf[24] & 0x0f);
3342 
3343 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3344 			" 0x%02x\n", proto_ident);
3345 
3346 	if (proto_ident != dest_tf_ops->get_fabric_proto_ident(dest_se_tpg)) {
3347 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3348 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3349 			" from fabric: %s\n", proto_ident,
3350 			dest_tf_ops->get_fabric_proto_ident(dest_se_tpg),
3351 			dest_tf_ops->get_fabric_name());
3352 		ret = TCM_INVALID_PARAMETER_LIST;
3353 		goto out;
3354 	}
3355 	if (dest_tf_ops->tpg_parse_pr_out_transport_id == NULL) {
3356 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Fabric does not"
3357 			" containg a valid tpg_parse_pr_out_transport_id"
3358 			" function pointer\n");
3359 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3360 		goto out;
3361 	}
3362 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(dest_se_tpg,
3363 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3364 	if (!initiator_str) {
3365 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3366 			" initiator_str from Transport ID\n");
3367 		ret = TCM_INVALID_PARAMETER_LIST;
3368 		goto out;
3369 	}
3370 
3371 	transport_kunmap_data_sg(cmd);
3372 	buf = NULL;
3373 
3374 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3375 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3376 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3377 		iport_ptr : "");
3378 	/*
3379 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3380 	 * action specifies a TransportID that is the same as the initiator port
3381 	 * of the I_T nexus for the command received, then the command shall
3382 	 * be terminated with CHECK CONDITION status, with the sense key set to
3383 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3384 	 * IN PARAMETER LIST.
3385 	 */
3386 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3387 	matching_iname = (!strcmp(initiator_str,
3388 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3389 	if (!matching_iname)
3390 		goto after_iport_check;
3391 
3392 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3393 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3394 			" matches: %s on received I_T Nexus\n", initiator_str,
3395 			pr_reg_nacl->initiatorname);
3396 		ret = TCM_INVALID_PARAMETER_LIST;
3397 		goto out;
3398 	}
3399 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3400 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3401 			" matches: %s %s on received I_T Nexus\n",
3402 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3403 			pr_reg->pr_reg_isid);
3404 		ret = TCM_INVALID_PARAMETER_LIST;
3405 		goto out;
3406 	}
3407 after_iport_check:
3408 	/*
3409 	 * Locate the destination struct se_node_acl from the received Transport ID
3410 	 */
3411 	spin_lock_irq(&dest_se_tpg->acl_node_lock);
3412 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3413 				initiator_str);
3414 	if (dest_node_acl) {
3415 		atomic_inc(&dest_node_acl->acl_pr_ref_count);
3416 		smp_mb__after_atomic_inc();
3417 	}
3418 	spin_unlock_irq(&dest_se_tpg->acl_node_lock);
3419 
3420 	if (!dest_node_acl) {
3421 		pr_err("Unable to locate %s dest_node_acl for"
3422 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3423 			initiator_str);
3424 		ret = TCM_INVALID_PARAMETER_LIST;
3425 		goto out;
3426 	}
3427 
3428 	if (core_scsi3_nodeacl_depend_item(dest_node_acl)) {
3429 		pr_err("core_scsi3_nodeacl_depend_item() for"
3430 			" dest_node_acl\n");
3431 		atomic_dec(&dest_node_acl->acl_pr_ref_count);
3432 		smp_mb__after_atomic_dec();
3433 		dest_node_acl = NULL;
3434 		ret = TCM_INVALID_PARAMETER_LIST;
3435 		goto out;
3436 	}
3437 
3438 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3439 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3440 		dest_node_acl->initiatorname);
3441 
3442 	/*
3443 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3444 	 * PORT IDENTIFIER.
3445 	 */
3446 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3447 	if (!dest_se_deve) {
3448 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3449 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3450 		ret = TCM_INVALID_PARAMETER_LIST;
3451 		goto out;
3452 	}
3453 
3454 	if (core_scsi3_lunacl_depend_item(dest_se_deve)) {
3455 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3456 		atomic_dec(&dest_se_deve->pr_ref_count);
3457 		smp_mb__after_atomic_dec();
3458 		dest_se_deve = NULL;
3459 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3460 		goto out;
3461 	}
3462 
3463 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3464 		" ACL for dest_se_deve->mapped_lun: %u\n",
3465 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3466 		dest_se_deve->mapped_lun);
3467 
3468 	/*
3469 	 * A persistent reservation needs to already existing in order to
3470 	 * successfully complete the REGISTER_AND_MOVE service action..
3471 	 */
3472 	spin_lock(&dev->dev_reservation_lock);
3473 	pr_res_holder = dev->dev_pr_res_holder;
3474 	if (!pr_res_holder) {
3475 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3476 			" currently held\n");
3477 		spin_unlock(&dev->dev_reservation_lock);
3478 		ret = TCM_INVALID_CDB_FIELD;
3479 		goto out;
3480 	}
3481 	/*
3482 	 * The received on I_T Nexus must be the reservation holder.
3483 	 *
3484 	 * From spc4r17 section 5.7.8  Table 50 --
3485 	 * 	Register behaviors for a REGISTER AND MOVE service action
3486 	 */
3487 	if (pr_res_holder != pr_reg) {
3488 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3489 			" Nexus is not reservation holder\n");
3490 		spin_unlock(&dev->dev_reservation_lock);
3491 		ret = TCM_RESERVATION_CONFLICT;
3492 		goto out;
3493 	}
3494 	/*
3495 	 * From spc4r17 section 5.7.8: registering and moving reservation
3496 	 *
3497 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3498 	 * action is received and the established persistent reservation is a
3499 	 * Write Exclusive - All Registrants type or Exclusive Access -
3500 	 * All Registrants type reservation, then the command shall be completed
3501 	 * with RESERVATION CONFLICT status.
3502 	 */
3503 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3504 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3505 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3506 			" reservation for type: %s\n",
3507 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3508 		spin_unlock(&dev->dev_reservation_lock);
3509 		ret = TCM_RESERVATION_CONFLICT;
3510 		goto out;
3511 	}
3512 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3513 	/*
3514 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3515 	 */
3516 	type = pr_res_holder->pr_res_type;
3517 	scope = pr_res_holder->pr_res_type;
3518 	/*
3519 	 * c) Associate the reservation key specified in the SERVICE ACTION
3520 	 *    RESERVATION KEY field with the I_T nexus specified as the
3521 	 *    destination of the register and move, where:
3522 	 *    A) The I_T nexus is specified by the TransportID and the
3523 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3524 	 *    B) Regardless of the TransportID format used, the association for
3525 	 *       the initiator port is based on either the initiator port name
3526 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3527 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3528 	 *       transport protocols where port names are not required;
3529 	 * d) Register the reservation key specified in the SERVICE ACTION
3530 	 *    RESERVATION KEY field;
3531 	 * e) Retain the reservation key specified in the SERVICE ACTION
3532 	 *    RESERVATION KEY field and associated information;
3533 	 *
3534 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3535 	 * register an I_T nexus that is already registered with the same
3536 	 * reservation key or a different reservation key.
3537 	 */
3538 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3539 					iport_ptr);
3540 	if (!dest_pr_reg) {
3541 		if (core_scsi3_alloc_registration(cmd->se_dev,
3542 				dest_node_acl, dest_se_deve, iport_ptr,
3543 				sa_res_key, 0, aptpl, 2, 1)) {
3544 			spin_unlock(&dev->dev_reservation_lock);
3545 			ret = TCM_INVALID_PARAMETER_LIST;
3546 			goto out;
3547 		}
3548 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3549 						iport_ptr);
3550 		new_reg = 1;
3551 	}
3552 	/*
3553 	 * f) Release the persistent reservation for the persistent reservation
3554 	 *    holder (i.e., the I_T nexus on which the
3555 	 */
3556 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3557 			dev->dev_pr_res_holder, 0);
3558 	/*
3559 	 * g) Move the persistent reservation to the specified I_T nexus using
3560 	 *    the same scope and type as the persistent reservation released in
3561 	 *    item f); and
3562 	 */
3563 	dev->dev_pr_res_holder = dest_pr_reg;
3564 	dest_pr_reg->pr_res_holder = 1;
3565 	dest_pr_reg->pr_res_type = type;
3566 	pr_reg->pr_res_scope = scope;
3567 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
3568 				PR_REG_ISID_ID_LEN);
3569 	/*
3570 	 * Increment PRGeneration for existing registrations..
3571 	 */
3572 	if (!new_reg)
3573 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3574 	spin_unlock(&dev->dev_reservation_lock);
3575 
3576 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3577 		" created new reservation holder TYPE: %s on object RTPI:"
3578 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3579 		core_scsi3_pr_dump_type(type), rtpi,
3580 		dest_pr_reg->pr_res_generation);
3581 	pr_debug("SPC-3 PR Successfully moved reservation from"
3582 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3583 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3584 		(prf_isid) ? &i_buf[0] : "", dest_tf_ops->get_fabric_name(),
3585 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3586 		iport_ptr : "");
3587 	/*
3588 	 * It is now safe to release configfs group dependencies for destination
3589 	 * of Transport ID Initiator Device/Port Identifier
3590 	 */
3591 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3592 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3593 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3594 	/*
3595 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3596 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3597 	 */
3598 	if (unreg) {
3599 		spin_lock(&pr_tmpl->registration_lock);
3600 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3601 		spin_unlock(&pr_tmpl->registration_lock);
3602 	} else
3603 		core_scsi3_put_pr_reg(pr_reg);
3604 
3605 	/*
3606 	 * Clear the APTPL metadata if APTPL has been disabled, otherwise
3607 	 * write out the updated metadata to struct file for this SCSI device.
3608 	 */
3609 	if (!aptpl) {
3610 		pr_tmpl->pr_aptpl_active = 0;
3611 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
3612 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
3613 				" REGISTER_AND_MOVE\n");
3614 	} else {
3615 		pr_tmpl->pr_aptpl_active = 1;
3616 		if (!core_scsi3_update_and_write_aptpl(cmd->se_dev,
3617 				&dest_pr_reg->pr_aptpl_buf[0],
3618 				pr_tmpl->pr_aptpl_buf_len)) {
3619 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for"
3620 					" REGISTER_AND_MOVE\n");
3621 		}
3622 	}
3623 
3624 	transport_kunmap_data_sg(cmd);
3625 
3626 	core_scsi3_put_pr_reg(dest_pr_reg);
3627 	return 0;
3628 out:
3629 	if (buf)
3630 		transport_kunmap_data_sg(cmd);
3631 	if (dest_se_deve)
3632 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3633 	if (dest_node_acl)
3634 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3635 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3636 
3637 out_put_pr_reg:
3638 	core_scsi3_put_pr_reg(pr_reg);
3639 	return ret;
3640 }
3641 
3642 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3643 {
3644 	unsigned int __v1, __v2;
3645 
3646 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3647 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3648 
3649 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3650 }
3651 
3652 /*
3653  * See spc4r17 section 6.14 Table 170
3654  */
3655 sense_reason_t
3656 target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3657 {
3658 	unsigned char *cdb = &cmd->t_task_cdb[0];
3659 	unsigned char *buf;
3660 	u64 res_key, sa_res_key;
3661 	int sa, scope, type, aptpl;
3662 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3663 	sense_reason_t ret;
3664 
3665 	/*
3666 	 * Following spc2r20 5.5.1 Reservations overview:
3667 	 *
3668 	 * If a logical unit has been reserved by any RESERVE command and is
3669 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3670 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3671 	 * initiator or service action and shall terminate with a RESERVATION
3672 	 * CONFLICT status.
3673 	 */
3674 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
3675 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3676 			" SPC-2 reservation is held, returning"
3677 			" RESERVATION_CONFLICT\n");
3678 		return TCM_RESERVATION_CONFLICT;
3679 	}
3680 
3681 	/*
3682 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3683 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3684 	 */
3685 	if (!cmd->se_sess)
3686 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3687 
3688 	if (cmd->data_length < 24) {
3689 		pr_warn("SPC-PR: Received PR OUT parameter list"
3690 			" length too small: %u\n", cmd->data_length);
3691 		return TCM_INVALID_PARAMETER_LIST;
3692 	}
3693 
3694 	/*
3695 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3696 	 */
3697 	sa = (cdb[1] & 0x1f);
3698 	scope = (cdb[2] & 0xf0);
3699 	type = (cdb[2] & 0x0f);
3700 
3701 	buf = transport_kmap_data_sg(cmd);
3702 	if (!buf)
3703 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3704 
3705 	/*
3706 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3707 	 */
3708 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3709 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3710 	/*
3711 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3712 	 * SCSI TransportIDs.
3713 	 */
3714 	if (sa != PRO_REGISTER_AND_MOVE) {
3715 		spec_i_pt = (buf[20] & 0x08);
3716 		all_tg_pt = (buf[20] & 0x04);
3717 		aptpl = (buf[20] & 0x01);
3718 	} else {
3719 		aptpl = (buf[17] & 0x01);
3720 		unreg = (buf[17] & 0x02);
3721 	}
3722 	transport_kunmap_data_sg(cmd);
3723 	buf = NULL;
3724 
3725 	/*
3726 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3727 	 */
3728 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER))
3729 		return TCM_INVALID_PARAMETER_LIST;
3730 
3731 	/*
3732 	 * From spc4r17 section 6.14:
3733 	 *
3734 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3735 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3736 	 * the command shall be terminated with CHECK CONDITION status, with
3737 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3738 	 * code set to PARAMETER LIST LENGTH ERROR.
3739 	 */
3740 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3741 	    (cmd->data_length != 24)) {
3742 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3743 			" list length: %u\n", cmd->data_length);
3744 		return TCM_INVALID_PARAMETER_LIST;
3745 	}
3746 
3747 	/*
3748 	 * (core_scsi3_emulate_pro_* function parameters
3749 	 * are defined by spc4r17 Table 174:
3750 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3751 	 */
3752 	switch (sa) {
3753 	case PRO_REGISTER:
3754 		ret = core_scsi3_emulate_pro_register(cmd,
3755 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 0);
3756 		break;
3757 	case PRO_RESERVE:
3758 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3759 		break;
3760 	case PRO_RELEASE:
3761 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3762 		break;
3763 	case PRO_CLEAR:
3764 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3765 		break;
3766 	case PRO_PREEMPT:
3767 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3768 					res_key, sa_res_key, 0);
3769 		break;
3770 	case PRO_PREEMPT_AND_ABORT:
3771 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3772 					res_key, sa_res_key, 1);
3773 		break;
3774 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3775 		ret = core_scsi3_emulate_pro_register(cmd,
3776 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 1);
3777 		break;
3778 	case PRO_REGISTER_AND_MOVE:
3779 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3780 				sa_res_key, aptpl, unreg);
3781 		break;
3782 	default:
3783 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3784 			" action: 0x%02x\n", cdb[1] & 0x1f);
3785 		return TCM_INVALID_CDB_FIELD;
3786 	}
3787 
3788 	if (!ret)
3789 		target_complete_cmd(cmd, GOOD);
3790 	return ret;
3791 }
3792 
3793 /*
3794  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3795  *
3796  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3797  */
3798 static sense_reason_t
3799 core_scsi3_pri_read_keys(struct se_cmd *cmd)
3800 {
3801 	struct se_device *dev = cmd->se_dev;
3802 	struct t10_pr_registration *pr_reg;
3803 	unsigned char *buf;
3804 	u32 add_len = 0, off = 8;
3805 
3806 	if (cmd->data_length < 8) {
3807 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3808 			" too small\n", cmd->data_length);
3809 		return TCM_INVALID_CDB_FIELD;
3810 	}
3811 
3812 	buf = transport_kmap_data_sg(cmd);
3813 	if (!buf)
3814 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3815 
3816 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3817 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3818 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3819 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3820 
3821 	spin_lock(&dev->t10_pr.registration_lock);
3822 	list_for_each_entry(pr_reg, &dev->t10_pr.registration_list,
3823 			pr_reg_list) {
3824 		/*
3825 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3826 		 * next reservation key list descriptor.
3827 		 */
3828 		if ((add_len + 8) > (cmd->data_length - 8))
3829 			break;
3830 
3831 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3832 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3833 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3834 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3835 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3836 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3837 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3838 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3839 
3840 		add_len += 8;
3841 	}
3842 	spin_unlock(&dev->t10_pr.registration_lock);
3843 
3844 	buf[4] = ((add_len >> 24) & 0xff);
3845 	buf[5] = ((add_len >> 16) & 0xff);
3846 	buf[6] = ((add_len >> 8) & 0xff);
3847 	buf[7] = (add_len & 0xff);
3848 
3849 	transport_kunmap_data_sg(cmd);
3850 
3851 	return 0;
3852 }
3853 
3854 /*
3855  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3856  *
3857  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3858  */
3859 static sense_reason_t
3860 core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3861 {
3862 	struct se_device *dev = cmd->se_dev;
3863 	struct t10_pr_registration *pr_reg;
3864 	unsigned char *buf;
3865 	u64 pr_res_key;
3866 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3867 
3868 	if (cmd->data_length < 8) {
3869 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3870 			" too small\n", cmd->data_length);
3871 		return TCM_INVALID_CDB_FIELD;
3872 	}
3873 
3874 	buf = transport_kmap_data_sg(cmd);
3875 	if (!buf)
3876 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3877 
3878 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
3879 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
3880 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
3881 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
3882 
3883 	spin_lock(&dev->dev_reservation_lock);
3884 	pr_reg = dev->dev_pr_res_holder;
3885 	if (pr_reg) {
3886 		/*
3887 		 * Set the hardcoded Additional Length
3888 		 */
3889 		buf[4] = ((add_len >> 24) & 0xff);
3890 		buf[5] = ((add_len >> 16) & 0xff);
3891 		buf[6] = ((add_len >> 8) & 0xff);
3892 		buf[7] = (add_len & 0xff);
3893 
3894 		if (cmd->data_length < 22)
3895 			goto err;
3896 
3897 		/*
3898 		 * Set the Reservation key.
3899 		 *
3900 		 * From spc4r17, section 5.7.10:
3901 		 * A persistent reservation holder has its reservation key
3902 		 * returned in the parameter data from a PERSISTENT
3903 		 * RESERVE IN command with READ RESERVATION service action as
3904 		 * follows:
3905 		 * a) For a persistent reservation of the type Write Exclusive
3906 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3907 		 *      the reservation key shall be set to zero; or
3908 		 * b) For all other persistent reservation types, the
3909 		 *    reservation key shall be set to the registered
3910 		 *    reservation key for the I_T nexus that holds the
3911 		 *    persistent reservation.
3912 		 */
3913 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3914 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3915 			pr_res_key = 0;
3916 		else
3917 			pr_res_key = pr_reg->pr_res_key;
3918 
3919 		buf[8] = ((pr_res_key >> 56) & 0xff);
3920 		buf[9] = ((pr_res_key >> 48) & 0xff);
3921 		buf[10] = ((pr_res_key >> 40) & 0xff);
3922 		buf[11] = ((pr_res_key >> 32) & 0xff);
3923 		buf[12] = ((pr_res_key >> 24) & 0xff);
3924 		buf[13] = ((pr_res_key >> 16) & 0xff);
3925 		buf[14] = ((pr_res_key >> 8) & 0xff);
3926 		buf[15] = (pr_res_key & 0xff);
3927 		/*
3928 		 * Set the SCOPE and TYPE
3929 		 */
3930 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3931 			  (pr_reg->pr_res_type & 0x0f);
3932 	}
3933 
3934 err:
3935 	spin_unlock(&dev->dev_reservation_lock);
3936 	transport_kunmap_data_sg(cmd);
3937 
3938 	return 0;
3939 }
3940 
3941 /*
3942  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3943  *
3944  * See spc4r17 section 6.13.4 Table 165
3945  */
3946 static sense_reason_t
3947 core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3948 {
3949 	struct se_device *dev = cmd->se_dev;
3950 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
3951 	unsigned char *buf;
3952 	u16 add_len = 8; /* Hardcoded to 8. */
3953 
3954 	if (cmd->data_length < 6) {
3955 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
3956 			" %u too small\n", cmd->data_length);
3957 		return TCM_INVALID_CDB_FIELD;
3958 	}
3959 
3960 	buf = transport_kmap_data_sg(cmd);
3961 	if (!buf)
3962 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3963 
3964 	buf[0] = ((add_len << 8) & 0xff);
3965 	buf[1] = (add_len & 0xff);
3966 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
3967 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
3968 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
3969 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
3970 	/*
3971 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
3972 	 * set the TMV: Task Mask Valid bit.
3973 	 */
3974 	buf[3] |= 0x80;
3975 	/*
3976 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
3977 	 */
3978 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
3979 	/*
3980 	 * PTPL_A: Persistence across Target Power Loss Active bit
3981 	 */
3982 	if (pr_tmpl->pr_aptpl_active)
3983 		buf[3] |= 0x01;
3984 	/*
3985 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
3986 	 */
3987 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3988 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
3989 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
3990 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
3991 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
3992 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
3993 
3994 	transport_kunmap_data_sg(cmd);
3995 
3996 	return 0;
3997 }
3998 
3999 /*
4000  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
4001  *
4002  * See spc4r17 section 6.13.5 Table 168 and 169
4003  */
4004 static sense_reason_t
4005 core_scsi3_pri_read_full_status(struct se_cmd *cmd)
4006 {
4007 	struct se_device *dev = cmd->se_dev;
4008 	struct se_node_acl *se_nacl;
4009 	struct se_portal_group *se_tpg;
4010 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
4011 	struct t10_reservation *pr_tmpl = &dev->t10_pr;
4012 	unsigned char *buf;
4013 	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
4014 	u32 off = 8; /* off into first Full Status descriptor */
4015 	int format_code = 0;
4016 
4017 	if (cmd->data_length < 8) {
4018 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
4019 			" too small\n", cmd->data_length);
4020 		return TCM_INVALID_CDB_FIELD;
4021 	}
4022 
4023 	buf = transport_kmap_data_sg(cmd);
4024 	if (!buf)
4025 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
4026 
4027 	buf[0] = ((dev->t10_pr.pr_generation >> 24) & 0xff);
4028 	buf[1] = ((dev->t10_pr.pr_generation >> 16) & 0xff);
4029 	buf[2] = ((dev->t10_pr.pr_generation >> 8) & 0xff);
4030 	buf[3] = (dev->t10_pr.pr_generation & 0xff);
4031 
4032 	spin_lock(&pr_tmpl->registration_lock);
4033 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
4034 			&pr_tmpl->registration_list, pr_reg_list) {
4035 
4036 		se_nacl = pr_reg->pr_reg_nacl;
4037 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
4038 		add_desc_len = 0;
4039 
4040 		atomic_inc(&pr_reg->pr_res_holders);
4041 		smp_mb__after_atomic_inc();
4042 		spin_unlock(&pr_tmpl->registration_lock);
4043 		/*
4044 		 * Determine expected length of $FABRIC_MOD specific
4045 		 * TransportID full status descriptor..
4046 		 */
4047 		exp_desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id_len(
4048 				se_tpg, se_nacl, pr_reg, &format_code);
4049 
4050 		if ((exp_desc_len + add_len) > cmd->data_length) {
4051 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
4052 				" out of buffer: %d\n", cmd->data_length);
4053 			spin_lock(&pr_tmpl->registration_lock);
4054 			atomic_dec(&pr_reg->pr_res_holders);
4055 			smp_mb__after_atomic_dec();
4056 			break;
4057 		}
4058 		/*
4059 		 * Set RESERVATION KEY
4060 		 */
4061 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
4062 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
4063 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
4064 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
4065 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
4066 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
4067 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
4068 		buf[off++] = (pr_reg->pr_res_key & 0xff);
4069 		off += 4; /* Skip Over Reserved area */
4070 
4071 		/*
4072 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
4073 		 */
4074 		if (pr_reg->pr_reg_all_tg_pt)
4075 			buf[off] = 0x02;
4076 		/*
4077 		 * The struct se_lun pointer will be present for the
4078 		 * reservation holder for PR_HOLDER bit.
4079 		 *
4080 		 * Also, if this registration is the reservation
4081 		 * holder, fill in SCOPE and TYPE in the next byte.
4082 		 */
4083 		if (pr_reg->pr_res_holder) {
4084 			buf[off++] |= 0x01;
4085 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
4086 				     (pr_reg->pr_res_type & 0x0f);
4087 		} else
4088 			off += 2;
4089 
4090 		off += 4; /* Skip over reserved area */
4091 		/*
4092 		 * From spc4r17 6.3.15:
4093 		 *
4094 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4095 		 * IDENTIFIER field contains the relative port identifier (see
4096 		 * 3.1.120) of the target port that is part of the I_T nexus
4097 		 * described by this full status descriptor. If the ALL_TG_PT
4098 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4099 		 * IDENTIFIER field are not defined by this standard.
4100 		 */
4101 		if (!pr_reg->pr_reg_all_tg_pt) {
4102 			struct se_port *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
4103 
4104 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
4105 			buf[off++] = (port->sep_rtpi & 0xff);
4106 		} else
4107 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
4108 
4109 		/*
4110 		 * Now, have the $FABRIC_MOD fill in the protocol identifier
4111 		 */
4112 		desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id(se_tpg,
4113 				se_nacl, pr_reg, &format_code, &buf[off+4]);
4114 
4115 		spin_lock(&pr_tmpl->registration_lock);
4116 		atomic_dec(&pr_reg->pr_res_holders);
4117 		smp_mb__after_atomic_dec();
4118 		/*
4119 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4120 		 */
4121 		buf[off++] = ((desc_len >> 24) & 0xff);
4122 		buf[off++] = ((desc_len >> 16) & 0xff);
4123 		buf[off++] = ((desc_len >> 8) & 0xff);
4124 		buf[off++] = (desc_len & 0xff);
4125 		/*
4126 		 * Size of full desctipor header minus TransportID
4127 		 * containing $FABRIC_MOD specific) initiator device/port
4128 		 * WWN information.
4129 		 *
4130 		 *  See spc4r17 Section 6.13.5 Table 169
4131 		 */
4132 		add_desc_len = (24 + desc_len);
4133 
4134 		off += desc_len;
4135 		add_len += add_desc_len;
4136 	}
4137 	spin_unlock(&pr_tmpl->registration_lock);
4138 	/*
4139 	 * Set ADDITIONAL_LENGTH
4140 	 */
4141 	buf[4] = ((add_len >> 24) & 0xff);
4142 	buf[5] = ((add_len >> 16) & 0xff);
4143 	buf[6] = ((add_len >> 8) & 0xff);
4144 	buf[7] = (add_len & 0xff);
4145 
4146 	transport_kunmap_data_sg(cmd);
4147 
4148 	return 0;
4149 }
4150 
4151 sense_reason_t
4152 target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4153 {
4154 	sense_reason_t ret;
4155 
4156 	/*
4157 	 * Following spc2r20 5.5.1 Reservations overview:
4158 	 *
4159 	 * If a logical unit has been reserved by any RESERVE command and is
4160 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4161 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4162 	 * initiator or service action and shall terminate with a RESERVATION
4163 	 * CONFLICT status.
4164 	 */
4165 	if (cmd->se_dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) {
4166 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4167 			" SPC-2 reservation is held, returning"
4168 			" RESERVATION_CONFLICT\n");
4169 		return TCM_RESERVATION_CONFLICT;
4170 	}
4171 
4172 	switch (cmd->t_task_cdb[1] & 0x1f) {
4173 	case PRI_READ_KEYS:
4174 		ret = core_scsi3_pri_read_keys(cmd);
4175 		break;
4176 	case PRI_READ_RESERVATION:
4177 		ret = core_scsi3_pri_read_reservation(cmd);
4178 		break;
4179 	case PRI_REPORT_CAPABILITIES:
4180 		ret = core_scsi3_pri_report_capabilities(cmd);
4181 		break;
4182 	case PRI_READ_FULL_STATUS:
4183 		ret = core_scsi3_pri_read_full_status(cmd);
4184 		break;
4185 	default:
4186 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4187 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4188 		return TCM_INVALID_CDB_FIELD;
4189 	}
4190 
4191 	if (!ret)
4192 		target_complete_cmd(cmd, GOOD);
4193 	return ret;
4194 }
4195 
4196 sense_reason_t
4197 target_check_reservation(struct se_cmd *cmd)
4198 {
4199 	struct se_device *dev = cmd->se_dev;
4200 	sense_reason_t ret;
4201 
4202 	if (!cmd->se_sess)
4203 		return 0;
4204 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
4205 		return 0;
4206 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
4207 		return 0;
4208 
4209 	spin_lock(&dev->dev_reservation_lock);
4210 	if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS)
4211 		ret = target_scsi2_reservation_check(cmd);
4212 	else
4213 		ret = target_scsi3_pr_reservation_check(cmd);
4214 	spin_unlock(&dev->dev_reservation_lock);
4215 
4216 	return ret;
4217 }
4218