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  * Copyright (c) 2009, 2010 Rising Tide Systems
8  * Copyright (c) 2009, 2010 Linux-iSCSI.org
9  *
10  * Nicholas A. Bellinger <nab@kernel.org>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25  *
26  ******************************************************************************/
27 
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/list.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 int core_scsi2_reservation_seq_non_holder(
72 	struct se_cmd *cmd,
73 	unsigned char *cdb,
74 	u32 pr_reg_type)
75 {
76 	switch (cdb[0]) {
77 	case INQUIRY:
78 	case RELEASE:
79 	case RELEASE_10:
80 		return 0;
81 	default:
82 		return 1;
83 	}
84 
85 	return 1;
86 }
87 
88 static int core_scsi2_reservation_check(struct se_cmd *cmd, u32 *pr_reg_type)
89 {
90 	struct se_device *dev = cmd->se_dev;
91 	struct se_session *sess = cmd->se_sess;
92 	int ret;
93 
94 	if (!sess)
95 		return 0;
96 
97 	spin_lock(&dev->dev_reservation_lock);
98 	if (!dev->dev_reserved_node_acl || !sess) {
99 		spin_unlock(&dev->dev_reservation_lock);
100 		return 0;
101 	}
102 	if (dev->dev_reserved_node_acl != sess->se_node_acl) {
103 		spin_unlock(&dev->dev_reservation_lock);
104 		return -EINVAL;
105 	}
106 	if (!(dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID)) {
107 		spin_unlock(&dev->dev_reservation_lock);
108 		return 0;
109 	}
110 	ret = (dev->dev_res_bin_isid == sess->sess_bin_isid) ? 0 : -EINVAL;
111 	spin_unlock(&dev->dev_reservation_lock);
112 
113 	return ret;
114 }
115 
116 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
117 					struct se_node_acl *, struct se_session *);
118 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
119 
120 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
121 {
122 	struct se_session *se_sess = cmd->se_sess;
123 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
124 	struct t10_pr_registration *pr_reg;
125 	struct t10_reservation *pr_tmpl = &su_dev->t10_pr;
126 	int crh = (su_dev->t10_pr.res_type == SPC3_PERSISTENT_RESERVATIONS);
127 	int conflict = 0;
128 
129 	if (!crh)
130 		return -EINVAL;
131 
132 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
133 			se_sess);
134 	if (pr_reg) {
135 		/*
136 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
137 		 * behavior
138 		 *
139 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
140 		 * status, but no reservation shall be established and the
141 		 * persistent reservation shall not be changed, if the command
142 		 * is received from a) and b) below.
143 		 *
144 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
145 		 * status, but the persistent reservation shall not be released,
146 		 * if the command is received from a) and b)
147 		 *
148 		 * a) An I_T nexus that is a persistent reservation holder; or
149 		 * b) An I_T nexus that is registered if a registrants only or
150 		 *    all registrants type persistent reservation is present.
151 		 *
152 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
153 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
154 		 * as defined in SPC-2.
155 		 */
156 		if (pr_reg->pr_res_holder) {
157 			core_scsi3_put_pr_reg(pr_reg);
158 			return 1;
159 		}
160 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
161 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
162 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
163 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
164 			core_scsi3_put_pr_reg(pr_reg);
165 			return 1;
166 		}
167 		core_scsi3_put_pr_reg(pr_reg);
168 		conflict = 1;
169 	} else {
170 		/*
171 		 * Following spc2r20 5.5.1 Reservations overview:
172 		 *
173 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
174 		 * command with the REGISTER or the REGISTER AND IGNORE
175 		 * EXISTING KEY service action and is still registered by any
176 		 * initiator, all RESERVE commands and all RELEASE commands
177 		 * regardless of initiator shall conflict and shall terminate
178 		 * with a RESERVATION CONFLICT status.
179 		 */
180 		spin_lock(&pr_tmpl->registration_lock);
181 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
182 		spin_unlock(&pr_tmpl->registration_lock);
183 	}
184 
185 	if (conflict) {
186 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
187 			" while active SPC-3 registrations exist,"
188 			" returning RESERVATION_CONFLICT\n");
189 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
190 		return -EBUSY;
191 	}
192 
193 	return 0;
194 }
195 
196 int target_scsi2_reservation_release(struct se_task *task)
197 {
198 	struct se_cmd *cmd = task->task_se_cmd;
199 	struct se_device *dev = cmd->se_dev;
200 	struct se_session *sess = cmd->se_sess;
201 	struct se_portal_group *tpg = sess->se_tpg;
202 	int ret = 0, rc;
203 
204 	if (!sess || !tpg)
205 		goto out;
206 	rc = target_check_scsi2_reservation_conflict(cmd);
207 	if (rc == 1)
208 		goto out;
209 	else if (rc < 0) {
210 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
211 		ret = -EINVAL;
212 		goto out;
213 	}
214 
215 	ret = 0;
216 	spin_lock(&dev->dev_reservation_lock);
217 	if (!dev->dev_reserved_node_acl || !sess)
218 		goto out_unlock;
219 
220 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
221 		goto out_unlock;
222 
223 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
224 		goto out_unlock;
225 
226 	dev->dev_reserved_node_acl = NULL;
227 	dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
228 	if (dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID) {
229 		dev->dev_res_bin_isid = 0;
230 		dev->dev_flags &= ~DF_SPC2_RESERVATIONS_WITH_ISID;
231 	}
232 	pr_debug("SCSI-2 Released reservation for %s LUN: %u ->"
233 		" MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
234 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
235 		sess->se_node_acl->initiatorname);
236 
237 out_unlock:
238 	spin_unlock(&dev->dev_reservation_lock);
239 out:
240 	if (!ret) {
241 		task->task_scsi_status = GOOD;
242 		transport_complete_task(task, 1);
243 	}
244 	return ret;
245 }
246 
247 int target_scsi2_reservation_reserve(struct se_task *task)
248 {
249 	struct se_cmd *cmd = task->task_se_cmd;
250 	struct se_device *dev = cmd->se_dev;
251 	struct se_session *sess = cmd->se_sess;
252 	struct se_portal_group *tpg = sess->se_tpg;
253 	int ret = 0, rc;
254 
255 	if ((cmd->t_task_cdb[1] & 0x01) &&
256 	    (cmd->t_task_cdb[1] & 0x02)) {
257 		pr_err("LongIO and Obselete Bits set, returning"
258 				" ILLEGAL_REQUEST\n");
259 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
260 		ret = -EINVAL;
261 		goto out;
262 	}
263 	/*
264 	 * This is currently the case for target_core_mod passthrough struct se_cmd
265 	 * ops
266 	 */
267 	if (!sess || !tpg)
268 		goto out;
269 	rc = target_check_scsi2_reservation_conflict(cmd);
270 	if (rc == 1)
271 		goto out;
272 	else if (rc < 0) {
273 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
274 		ret = -EINVAL;
275 		goto out;
276 	}
277 
278 	ret = 0;
279 	spin_lock(&dev->dev_reservation_lock);
280 	if (dev->dev_reserved_node_acl &&
281 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
282 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
283 			tpg->se_tpg_tfo->get_fabric_name());
284 		pr_err("Original reserver LUN: %u %s\n",
285 			cmd->se_lun->unpacked_lun,
286 			dev->dev_reserved_node_acl->initiatorname);
287 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
288 			" from %s \n", cmd->se_lun->unpacked_lun,
289 			cmd->se_deve->mapped_lun,
290 			sess->se_node_acl->initiatorname);
291 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
292 		ret = -EINVAL;
293 		goto out_unlock;
294 	}
295 
296 	dev->dev_reserved_node_acl = sess->se_node_acl;
297 	dev->dev_flags |= DF_SPC2_RESERVATIONS;
298 	if (sess->sess_bin_isid != 0) {
299 		dev->dev_res_bin_isid = sess->sess_bin_isid;
300 		dev->dev_flags |= DF_SPC2_RESERVATIONS_WITH_ISID;
301 	}
302 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
303 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
304 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
305 		sess->se_node_acl->initiatorname);
306 
307 out_unlock:
308 	spin_unlock(&dev->dev_reservation_lock);
309 out:
310 	if (!ret) {
311 		task->task_scsi_status = GOOD;
312 		transport_complete_task(task, 1);
313 	}
314 	return ret;
315 }
316 
317 
318 /*
319  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
320  *
321  * This function is called by those initiator ports who are *NOT*
322  * the active PR reservation holder when a reservation is present.
323  */
324 static int core_scsi3_pr_seq_non_holder(
325 	struct se_cmd *cmd,
326 	unsigned char *cdb,
327 	u32 pr_reg_type)
328 {
329 	struct se_dev_entry *se_deve;
330 	struct se_session *se_sess = cmd->se_sess;
331 	int other_cdb = 0, ignore_reg;
332 	int registered_nexus = 0, ret = 1; /* Conflict by default */
333 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
334 	int we = 0; /* Write Exclusive */
335 	int legacy = 0; /* Act like a legacy device and return
336 			 * RESERVATION CONFLICT on some CDBs */
337 	/*
338 	 * A legacy SPC-2 reservation is being held.
339 	 */
340 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS)
341 		return core_scsi2_reservation_seq_non_holder(cmd,
342 					cdb, pr_reg_type);
343 
344 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
345 	/*
346 	 * Determine if the registration should be ignored due to
347 	 * non-matching ISIDs in core_scsi3_pr_reservation_check().
348 	 */
349 	ignore_reg = (pr_reg_type & 0x80000000);
350 	if (ignore_reg)
351 		pr_reg_type &= ~0x80000000;
352 
353 	switch (pr_reg_type) {
354 	case PR_TYPE_WRITE_EXCLUSIVE:
355 		we = 1;
356 	case PR_TYPE_EXCLUSIVE_ACCESS:
357 		/*
358 		 * Some commands are only allowed for the persistent reservation
359 		 * holder.
360 		 */
361 		if ((se_deve->def_pr_registered) && !(ignore_reg))
362 			registered_nexus = 1;
363 		break;
364 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
365 		we = 1;
366 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
367 		/*
368 		 * Some commands are only allowed for registered I_T Nexuses.
369 		 */
370 		reg_only = 1;
371 		if ((se_deve->def_pr_registered) && !(ignore_reg))
372 			registered_nexus = 1;
373 		break;
374 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
375 		we = 1;
376 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
377 		/*
378 		 * Each registered I_T Nexus is a reservation holder.
379 		 */
380 		all_reg = 1;
381 		if ((se_deve->def_pr_registered) && !(ignore_reg))
382 			registered_nexus = 1;
383 		break;
384 	default:
385 		return -EINVAL;
386 	}
387 	/*
388 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
389 	 */
390 	switch (cdb[0]) {
391 	case SECURITY_PROTOCOL_IN:
392 		if (registered_nexus)
393 			return 0;
394 		ret = (we) ? 0 : 1;
395 		break;
396 	case MODE_SENSE:
397 	case MODE_SENSE_10:
398 	case READ_ATTRIBUTE:
399 	case READ_BUFFER:
400 	case RECEIVE_DIAGNOSTIC:
401 		if (legacy) {
402 			ret = 1;
403 			break;
404 		}
405 		if (registered_nexus) {
406 			ret = 0;
407 			break;
408 		}
409 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
410 		break;
411 	case PERSISTENT_RESERVE_OUT:
412 		/*
413 		 * This follows PERSISTENT_RESERVE_OUT service actions that
414 		 * are allowed in the presence of various reservations.
415 		 * See spc4r17, table 46
416 		 */
417 		switch (cdb[1] & 0x1f) {
418 		case PRO_CLEAR:
419 		case PRO_PREEMPT:
420 		case PRO_PREEMPT_AND_ABORT:
421 			ret = (registered_nexus) ? 0 : 1;
422 			break;
423 		case PRO_REGISTER:
424 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
425 			ret = 0;
426 			break;
427 		case PRO_REGISTER_AND_MOVE:
428 		case PRO_RESERVE:
429 			ret = 1;
430 			break;
431 		case PRO_RELEASE:
432 			ret = (registered_nexus) ? 0 : 1;
433 			break;
434 		default:
435 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
436 				" action: 0x%02x\n", cdb[1] & 0x1f);
437 			return -EINVAL;
438 		}
439 		break;
440 	case RELEASE:
441 	case RELEASE_10:
442 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
443 		ret = 0;
444 		break;
445 	case RESERVE:
446 	case RESERVE_10:
447 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
448 		ret = 0;
449 		break;
450 	case TEST_UNIT_READY:
451 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
452 		break;
453 	case MAINTENANCE_IN:
454 		switch (cdb[1] & 0x1f) {
455 		case MI_MANAGEMENT_PROTOCOL_IN:
456 			if (registered_nexus) {
457 				ret = 0;
458 				break;
459 			}
460 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
461 			break;
462 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
463 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
464 			if (legacy) {
465 				ret = 1;
466 				break;
467 			}
468 			if (registered_nexus) {
469 				ret = 0;
470 				break;
471 			}
472 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
473 			break;
474 		case MI_REPORT_ALIASES:
475 		case MI_REPORT_IDENTIFYING_INFORMATION:
476 		case MI_REPORT_PRIORITY:
477 		case MI_REPORT_TARGET_PGS:
478 		case MI_REPORT_TIMESTAMP:
479 			ret = 0; /* Allowed */
480 			break;
481 		default:
482 			pr_err("Unknown MI Service Action: 0x%02x\n",
483 				(cdb[1] & 0x1f));
484 			return -EINVAL;
485 		}
486 		break;
487 	case ACCESS_CONTROL_IN:
488 	case ACCESS_CONTROL_OUT:
489 	case INQUIRY:
490 	case LOG_SENSE:
491 	case READ_MEDIA_SERIAL_NUMBER:
492 	case REPORT_LUNS:
493 	case REQUEST_SENSE:
494 	case PERSISTENT_RESERVE_IN:
495 		ret = 0; /*/ Allowed CDBs */
496 		break;
497 	default:
498 		other_cdb = 1;
499 		break;
500 	}
501 	/*
502 	 * Case where the CDB is explicitly allowed in the above switch
503 	 * statement.
504 	 */
505 	if (!ret && !other_cdb) {
506 #if 0
507 		pr_debug("Allowing explict CDB: 0x%02x for %s"
508 			" reservation holder\n", cdb[0],
509 			core_scsi3_pr_dump_type(pr_reg_type));
510 #endif
511 		return ret;
512 	}
513 	/*
514 	 * Check if write exclusive initiator ports *NOT* holding the
515 	 * WRITE_EXCLUSIVE_* reservation.
516 	 */
517 	if ((we) && !(registered_nexus)) {
518 		if (cmd->data_direction == DMA_TO_DEVICE) {
519 			/*
520 			 * Conflict for write exclusive
521 			 */
522 			pr_debug("%s Conflict for unregistered nexus"
523 				" %s CDB: 0x%02x to %s reservation\n",
524 				transport_dump_cmd_direction(cmd),
525 				se_sess->se_node_acl->initiatorname, cdb[0],
526 				core_scsi3_pr_dump_type(pr_reg_type));
527 			return 1;
528 		} else {
529 			/*
530 			 * Allow non WRITE CDBs for all Write Exclusive
531 			 * PR TYPEs to pass for registered and
532 			 * non-registered_nexuxes NOT holding the reservation.
533 			 *
534 			 * We only make noise for the unregisterd nexuses,
535 			 * as we expect registered non-reservation holding
536 			 * nexuses to issue CDBs.
537 			 */
538 #if 0
539 			if (!registered_nexus) {
540 				pr_debug("Allowing implict CDB: 0x%02x"
541 					" for %s reservation on unregistered"
542 					" nexus\n", cdb[0],
543 					core_scsi3_pr_dump_type(pr_reg_type));
544 			}
545 #endif
546 			return 0;
547 		}
548 	} else if ((reg_only) || (all_reg)) {
549 		if (registered_nexus) {
550 			/*
551 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
552 			 * allow commands from registered nexuses.
553 			 */
554 #if 0
555 			pr_debug("Allowing implict CDB: 0x%02x for %s"
556 				" reservation\n", cdb[0],
557 				core_scsi3_pr_dump_type(pr_reg_type));
558 #endif
559 			return 0;
560 		}
561 	}
562 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
563 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
564 		(registered_nexus) ? "" : "un",
565 		se_sess->se_node_acl->initiatorname, cdb[0],
566 		core_scsi3_pr_dump_type(pr_reg_type));
567 
568 	return 1; /* Conflict by default */
569 }
570 
571 static u32 core_scsi3_pr_generation(struct se_device *dev)
572 {
573 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
574 	u32 prg;
575 	/*
576 	 * PRGeneration field shall contain the value of a 32-bit wrapping
577 	 * counter mainted by the device server.
578 	 *
579 	 * Note that this is done regardless of Active Persist across
580 	 * Target PowerLoss (APTPL)
581 	 *
582 	 * See spc4r17 section 6.3.12 READ_KEYS service action
583 	 */
584 	spin_lock(&dev->dev_reservation_lock);
585 	prg = su_dev->t10_pr.pr_generation++;
586 	spin_unlock(&dev->dev_reservation_lock);
587 
588 	return prg;
589 }
590 
591 static int core_scsi3_pr_reservation_check(
592 	struct se_cmd *cmd,
593 	u32 *pr_reg_type)
594 {
595 	struct se_device *dev = cmd->se_dev;
596 	struct se_session *sess = cmd->se_sess;
597 	int ret;
598 
599 	if (!sess)
600 		return 0;
601 	/*
602 	 * A legacy SPC-2 reservation is being held.
603 	 */
604 	if (dev->dev_flags & DF_SPC2_RESERVATIONS)
605 		return core_scsi2_reservation_check(cmd, pr_reg_type);
606 
607 	spin_lock(&dev->dev_reservation_lock);
608 	if (!dev->dev_pr_res_holder) {
609 		spin_unlock(&dev->dev_reservation_lock);
610 		return 0;
611 	}
612 	*pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
613 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
614 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl) {
615 		spin_unlock(&dev->dev_reservation_lock);
616 		return -EINVAL;
617 	}
618 	if (!dev->dev_pr_res_holder->isid_present_at_reg) {
619 		spin_unlock(&dev->dev_reservation_lock);
620 		return 0;
621 	}
622 	ret = (dev->dev_pr_res_holder->pr_reg_bin_isid ==
623 	       sess->sess_bin_isid) ? 0 : -EINVAL;
624 	/*
625 	 * Use bit in *pr_reg_type to notify ISID mismatch in
626 	 * core_scsi3_pr_seq_non_holder().
627 	 */
628 	if (ret != 0)
629 		*pr_reg_type |= 0x80000000;
630 	spin_unlock(&dev->dev_reservation_lock);
631 
632 	return ret;
633 }
634 
635 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
636 	struct se_device *dev,
637 	struct se_node_acl *nacl,
638 	struct se_dev_entry *deve,
639 	unsigned char *isid,
640 	u64 sa_res_key,
641 	int all_tg_pt,
642 	int aptpl)
643 {
644 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
645 	struct t10_pr_registration *pr_reg;
646 
647 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
648 	if (!pr_reg) {
649 		pr_err("Unable to allocate struct t10_pr_registration\n");
650 		return NULL;
651 	}
652 
653 	pr_reg->pr_aptpl_buf = kzalloc(su_dev->t10_pr.pr_aptpl_buf_len,
654 					GFP_ATOMIC);
655 	if (!pr_reg->pr_aptpl_buf) {
656 		pr_err("Unable to allocate pr_reg->pr_aptpl_buf\n");
657 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
658 		return NULL;
659 	}
660 
661 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
662 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
663 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
664 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
665 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
666 	atomic_set(&pr_reg->pr_res_holders, 0);
667 	pr_reg->pr_reg_nacl = nacl;
668 	pr_reg->pr_reg_deve = deve;
669 	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
670 	pr_reg->pr_aptpl_target_lun = deve->se_lun->unpacked_lun;
671 	pr_reg->pr_res_key = sa_res_key;
672 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
673 	pr_reg->pr_reg_aptpl = aptpl;
674 	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
675 	/*
676 	 * If an ISID value for this SCSI Initiator Port exists,
677 	 * save it to the registration now.
678 	 */
679 	if (isid != NULL) {
680 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
681 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
682 		pr_reg->isid_present_at_reg = 1;
683 	}
684 
685 	return pr_reg;
686 }
687 
688 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
689 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
690 
691 /*
692  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
693  * modes.
694  */
695 static struct t10_pr_registration *__core_scsi3_alloc_registration(
696 	struct se_device *dev,
697 	struct se_node_acl *nacl,
698 	struct se_dev_entry *deve,
699 	unsigned char *isid,
700 	u64 sa_res_key,
701 	int all_tg_pt,
702 	int aptpl)
703 {
704 	struct se_dev_entry *deve_tmp;
705 	struct se_node_acl *nacl_tmp;
706 	struct se_port *port, *port_tmp;
707 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
708 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
709 	int ret;
710 	/*
711 	 * Create a registration for the I_T Nexus upon which the
712 	 * PROUT REGISTER was received.
713 	 */
714 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, deve, isid,
715 			sa_res_key, all_tg_pt, aptpl);
716 	if (!pr_reg)
717 		return NULL;
718 	/*
719 	 * Return pointer to pr_reg for ALL_TG_PT=0
720 	 */
721 	if (!all_tg_pt)
722 		return pr_reg;
723 	/*
724 	 * Create list of matching SCSI Initiator Port registrations
725 	 * for ALL_TG_PT=1
726 	 */
727 	spin_lock(&dev->se_port_lock);
728 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
729 		atomic_inc(&port->sep_tg_pt_ref_cnt);
730 		smp_mb__after_atomic_inc();
731 		spin_unlock(&dev->se_port_lock);
732 
733 		spin_lock_bh(&port->sep_alua_lock);
734 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
735 					alua_port_list) {
736 			/*
737 			 * This pointer will be NULL for demo mode MappedLUNs
738 			 * that have not been make explict via a ConfigFS
739 			 * MappedLUN group for the SCSI Initiator Node ACL.
740 			 */
741 			if (!deve_tmp->se_lun_acl)
742 				continue;
743 
744 			nacl_tmp = deve_tmp->se_lun_acl->se_lun_nacl;
745 			/*
746 			 * Skip the matching struct se_node_acl that is allocated
747 			 * above..
748 			 */
749 			if (nacl == nacl_tmp)
750 				continue;
751 			/*
752 			 * Only perform PR registrations for target ports on
753 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
754 			 * arrived.
755 			 */
756 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
757 				continue;
758 			/*
759 			 * Look for a matching Initiator Node ACL in ASCII format
760 			 */
761 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
762 				continue;
763 
764 			atomic_inc(&deve_tmp->pr_ref_count);
765 			smp_mb__after_atomic_inc();
766 			spin_unlock_bh(&port->sep_alua_lock);
767 			/*
768 			 * Grab a configfs group dependency that is released
769 			 * for the exception path at label out: below, or upon
770 			 * completion of adding ALL_TG_PT=1 registrations in
771 			 * __core_scsi3_add_registration()
772 			 */
773 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
774 			if (ret < 0) {
775 				pr_err("core_scsi3_lunacl_depend"
776 						"_item() failed\n");
777 				atomic_dec(&port->sep_tg_pt_ref_cnt);
778 				smp_mb__after_atomic_dec();
779 				atomic_dec(&deve_tmp->pr_ref_count);
780 				smp_mb__after_atomic_dec();
781 				goto out;
782 			}
783 			/*
784 			 * Located a matching SCSI Initiator Port on a different
785 			 * port, allocate the pr_reg_atp and attach it to the
786 			 * pr_reg->pr_reg_atp_list that will be processed once
787 			 * the original *pr_reg is processed in
788 			 * __core_scsi3_add_registration()
789 			 */
790 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
791 						nacl_tmp, deve_tmp, NULL,
792 						sa_res_key, all_tg_pt, aptpl);
793 			if (!pr_reg_atp) {
794 				atomic_dec(&port->sep_tg_pt_ref_cnt);
795 				smp_mb__after_atomic_dec();
796 				atomic_dec(&deve_tmp->pr_ref_count);
797 				smp_mb__after_atomic_dec();
798 				core_scsi3_lunacl_undepend_item(deve_tmp);
799 				goto out;
800 			}
801 
802 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
803 				      &pr_reg->pr_reg_atp_list);
804 			spin_lock_bh(&port->sep_alua_lock);
805 		}
806 		spin_unlock_bh(&port->sep_alua_lock);
807 
808 		spin_lock(&dev->se_port_lock);
809 		atomic_dec(&port->sep_tg_pt_ref_cnt);
810 		smp_mb__after_atomic_dec();
811 	}
812 	spin_unlock(&dev->se_port_lock);
813 
814 	return pr_reg;
815 out:
816 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
817 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
818 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
819 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
820 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
821 	}
822 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
823 	return NULL;
824 }
825 
826 int core_scsi3_alloc_aptpl_registration(
827 	struct t10_reservation *pr_tmpl,
828 	u64 sa_res_key,
829 	unsigned char *i_port,
830 	unsigned char *isid,
831 	u32 mapped_lun,
832 	unsigned char *t_port,
833 	u16 tpgt,
834 	u32 target_lun,
835 	int res_holder,
836 	int all_tg_pt,
837 	u8 type)
838 {
839 	struct t10_pr_registration *pr_reg;
840 
841 	if (!i_port || !t_port || !sa_res_key) {
842 		pr_err("Illegal parameters for APTPL registration\n");
843 		return -EINVAL;
844 	}
845 
846 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
847 	if (!pr_reg) {
848 		pr_err("Unable to allocate struct t10_pr_registration\n");
849 		return -ENOMEM;
850 	}
851 	pr_reg->pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len, GFP_KERNEL);
852 
853 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
854 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
855 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
856 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
857 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
858 	atomic_set(&pr_reg->pr_res_holders, 0);
859 	pr_reg->pr_reg_nacl = NULL;
860 	pr_reg->pr_reg_deve = NULL;
861 	pr_reg->pr_res_mapped_lun = mapped_lun;
862 	pr_reg->pr_aptpl_target_lun = target_lun;
863 	pr_reg->pr_res_key = sa_res_key;
864 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
865 	pr_reg->pr_reg_aptpl = 1;
866 	pr_reg->pr_reg_tg_pt_lun = NULL;
867 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
868 	pr_reg->pr_res_type = type;
869 	/*
870 	 * If an ISID value had been saved in APTPL metadata for this
871 	 * SCSI Initiator Port, restore it now.
872 	 */
873 	if (isid != NULL) {
874 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
875 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
876 		pr_reg->isid_present_at_reg = 1;
877 	}
878 	/*
879 	 * Copy the i_port and t_port information from caller.
880 	 */
881 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
882 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
883 	pr_reg->pr_reg_tpgt = tpgt;
884 	/*
885 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
886 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
887 	 * the Initiator Node LUN ACL from the fabric module is created for
888 	 * this registration.
889 	 */
890 	pr_reg->pr_res_holder = res_holder;
891 
892 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
893 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
894 			" metadata\n", (res_holder) ? "+reservation" : "");
895 	return 0;
896 }
897 
898 static void core_scsi3_aptpl_reserve(
899 	struct se_device *dev,
900 	struct se_portal_group *tpg,
901 	struct se_node_acl *node_acl,
902 	struct t10_pr_registration *pr_reg)
903 {
904 	char i_buf[PR_REG_ISID_ID_LEN];
905 	int prf_isid;
906 
907 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
908 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
909 				PR_REG_ISID_ID_LEN);
910 
911 	spin_lock(&dev->dev_reservation_lock);
912 	dev->dev_pr_res_holder = pr_reg;
913 	spin_unlock(&dev->dev_reservation_lock);
914 
915 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
916 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
917 		tpg->se_tpg_tfo->get_fabric_name(),
918 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
919 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
920 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
921 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
922 		(prf_isid) ? &i_buf[0] : "");
923 }
924 
925 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
926 				struct t10_pr_registration *, int, int);
927 
928 static int __core_scsi3_check_aptpl_registration(
929 	struct se_device *dev,
930 	struct se_portal_group *tpg,
931 	struct se_lun *lun,
932 	u32 target_lun,
933 	struct se_node_acl *nacl,
934 	struct se_dev_entry *deve)
935 {
936 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
937 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
938 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
939 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
940 	u16 tpgt;
941 
942 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
943 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
944 	/*
945 	 * Copy Initiator Port information from struct se_node_acl
946 	 */
947 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
948 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
949 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
950 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
951 	/*
952 	 * Look for the matching registrations+reservation from those
953 	 * created from APTPL metadata.  Note that multiple registrations
954 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
955 	 * TransportIDs.
956 	 */
957 	spin_lock(&pr_tmpl->aptpl_reg_lock);
958 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
959 				pr_reg_aptpl_list) {
960 		if (!strcmp(pr_reg->pr_iport, i_port) &&
961 		     (pr_reg->pr_res_mapped_lun == deve->mapped_lun) &&
962 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
963 		     (pr_reg->pr_reg_tpgt == tpgt) &&
964 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
965 
966 			pr_reg->pr_reg_nacl = nacl;
967 			pr_reg->pr_reg_deve = deve;
968 			pr_reg->pr_reg_tg_pt_lun = lun;
969 
970 			list_del(&pr_reg->pr_reg_aptpl_list);
971 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
972 			/*
973 			 * At this point all of the pointers in *pr_reg will
974 			 * be setup, so go ahead and add the registration.
975 			 */
976 
977 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
978 			/*
979 			 * If this registration is the reservation holder,
980 			 * make that happen now..
981 			 */
982 			if (pr_reg->pr_res_holder)
983 				core_scsi3_aptpl_reserve(dev, tpg,
984 						nacl, pr_reg);
985 			/*
986 			 * Reenable pr_aptpl_active to accept new metadata
987 			 * updates once the SCSI device is active again..
988 			 */
989 			spin_lock(&pr_tmpl->aptpl_reg_lock);
990 			pr_tmpl->pr_aptpl_active = 1;
991 		}
992 	}
993 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
994 
995 	return 0;
996 }
997 
998 int core_scsi3_check_aptpl_registration(
999 	struct se_device *dev,
1000 	struct se_portal_group *tpg,
1001 	struct se_lun *lun,
1002 	struct se_lun_acl *lun_acl)
1003 {
1004 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1005 	struct se_node_acl *nacl = lun_acl->se_lun_nacl;
1006 	struct se_dev_entry *deve = nacl->device_list[lun_acl->mapped_lun];
1007 
1008 	if (su_dev->t10_pr.res_type != SPC3_PERSISTENT_RESERVATIONS)
1009 		return 0;
1010 
1011 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
1012 				lun->unpacked_lun, nacl, deve);
1013 }
1014 
1015 static void __core_scsi3_dump_registration(
1016 	struct target_core_fabric_ops *tfo,
1017 	struct se_device *dev,
1018 	struct se_node_acl *nacl,
1019 	struct t10_pr_registration *pr_reg,
1020 	int register_type)
1021 {
1022 	struct se_portal_group *se_tpg = nacl->se_tpg;
1023 	char i_buf[PR_REG_ISID_ID_LEN];
1024 	int prf_isid;
1025 
1026 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
1027 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1028 				PR_REG_ISID_ID_LEN);
1029 
1030 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1031 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == 2) ?
1032 		"_AND_MOVE" : (register_type == 1) ?
1033 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1034 		(prf_isid) ? i_buf : "");
1035 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1036 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
1037 		tfo->tpg_get_tag(se_tpg));
1038 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1039 		" Port(s)\n",  tfo->get_fabric_name(),
1040 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1041 		dev->transport->name);
1042 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1043 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
1044 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1045 		pr_reg->pr_reg_aptpl);
1046 }
1047 
1048 /*
1049  * this function can be called with struct se_device->dev_reservation_lock
1050  * when register_move = 1
1051  */
1052 static void __core_scsi3_add_registration(
1053 	struct se_device *dev,
1054 	struct se_node_acl *nacl,
1055 	struct t10_pr_registration *pr_reg,
1056 	int register_type,
1057 	int register_move)
1058 {
1059 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1060 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1061 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1062 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1063 
1064 	/*
1065 	 * Increment PRgeneration counter for struct se_device upon a successful
1066 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1067 	 *
1068 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1069 	 * action, the struct se_device->dev_reservation_lock will already be held,
1070 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1071 	 * for the REGISTER.
1072 	 */
1073 	pr_reg->pr_res_generation = (register_move) ?
1074 			su_dev->t10_pr.pr_generation++ :
1075 			core_scsi3_pr_generation(dev);
1076 
1077 	spin_lock(&pr_tmpl->registration_lock);
1078 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1079 	pr_reg->pr_reg_deve->def_pr_registered = 1;
1080 
1081 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1082 	spin_unlock(&pr_tmpl->registration_lock);
1083 	/*
1084 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1085 	 */
1086 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1087 		return;
1088 	/*
1089 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1090 	 * allocated in __core_scsi3_alloc_registration()
1091 	 */
1092 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1093 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1094 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1095 
1096 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1097 
1098 		spin_lock(&pr_tmpl->registration_lock);
1099 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1100 			      &pr_tmpl->registration_list);
1101 		pr_reg_tmp->pr_reg_deve->def_pr_registered = 1;
1102 
1103 		__core_scsi3_dump_registration(tfo, dev,
1104 				pr_reg_tmp->pr_reg_nacl, pr_reg_tmp,
1105 				register_type);
1106 		spin_unlock(&pr_tmpl->registration_lock);
1107 		/*
1108 		 * Drop configfs group dependency reference from
1109 		 * __core_scsi3_alloc_registration()
1110 		 */
1111 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1112 	}
1113 }
1114 
1115 static int core_scsi3_alloc_registration(
1116 	struct se_device *dev,
1117 	struct se_node_acl *nacl,
1118 	struct se_dev_entry *deve,
1119 	unsigned char *isid,
1120 	u64 sa_res_key,
1121 	int all_tg_pt,
1122 	int aptpl,
1123 	int register_type,
1124 	int register_move)
1125 {
1126 	struct t10_pr_registration *pr_reg;
1127 
1128 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, deve, isid,
1129 			sa_res_key, all_tg_pt, aptpl);
1130 	if (!pr_reg)
1131 		return -EPERM;
1132 
1133 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1134 			register_type, register_move);
1135 	return 0;
1136 }
1137 
1138 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1139 	struct se_device *dev,
1140 	struct se_node_acl *nacl,
1141 	unsigned char *isid)
1142 {
1143 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1144 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1145 	struct se_portal_group *tpg;
1146 
1147 	spin_lock(&pr_tmpl->registration_lock);
1148 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1149 			&pr_tmpl->registration_list, pr_reg_list) {
1150 		/*
1151 		 * First look for a matching struct se_node_acl
1152 		 */
1153 		if (pr_reg->pr_reg_nacl != nacl)
1154 			continue;
1155 
1156 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1157 		/*
1158 		 * If this registration does NOT contain a fabric provided
1159 		 * ISID, then we have found a match.
1160 		 */
1161 		if (!pr_reg->isid_present_at_reg) {
1162 			/*
1163 			 * Determine if this SCSI device server requires that
1164 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1165 			 * for fabric modules (iSCSI) requiring them.
1166 			 */
1167 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1168 				if (dev->se_sub_dev->se_dev_attrib.enforce_pr_isids)
1169 					continue;
1170 			}
1171 			atomic_inc(&pr_reg->pr_res_holders);
1172 			smp_mb__after_atomic_inc();
1173 			spin_unlock(&pr_tmpl->registration_lock);
1174 			return pr_reg;
1175 		}
1176 		/*
1177 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1178 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1179 		 * matching ISID to be provided by the local SCSI Initiator Port.
1180 		 */
1181 		if (!isid)
1182 			continue;
1183 		if (strcmp(isid, pr_reg->pr_reg_isid))
1184 			continue;
1185 
1186 		atomic_inc(&pr_reg->pr_res_holders);
1187 		smp_mb__after_atomic_inc();
1188 		spin_unlock(&pr_tmpl->registration_lock);
1189 		return pr_reg;
1190 	}
1191 	spin_unlock(&pr_tmpl->registration_lock);
1192 
1193 	return NULL;
1194 }
1195 
1196 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1197 	struct se_device *dev,
1198 	struct se_node_acl *nacl,
1199 	struct se_session *sess)
1200 {
1201 	struct se_portal_group *tpg = nacl->se_tpg;
1202 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1203 
1204 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1205 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1206 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1207 					PR_REG_ISID_LEN);
1208 		isid_ptr = &buf[0];
1209 	}
1210 
1211 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1212 }
1213 
1214 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1215 {
1216 	atomic_dec(&pr_reg->pr_res_holders);
1217 	smp_mb__after_atomic_dec();
1218 }
1219 
1220 static int core_scsi3_check_implict_release(
1221 	struct se_device *dev,
1222 	struct t10_pr_registration *pr_reg)
1223 {
1224 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1225 	struct t10_pr_registration *pr_res_holder;
1226 	int ret = 0;
1227 
1228 	spin_lock(&dev->dev_reservation_lock);
1229 	pr_res_holder = dev->dev_pr_res_holder;
1230 	if (!pr_res_holder) {
1231 		spin_unlock(&dev->dev_reservation_lock);
1232 		return ret;
1233 	}
1234 	if (pr_res_holder == pr_reg) {
1235 		/*
1236 		 * Perform an implict RELEASE if the registration that
1237 		 * is being released is holding the reservation.
1238 		 *
1239 		 * From spc4r17, section 5.7.11.1:
1240 		 *
1241 		 * e) If the I_T nexus is the persistent reservation holder
1242 		 *    and the persistent reservation is not an all registrants
1243 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1244 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1245 		 *    service action with the SERVICE ACTION RESERVATION KEY
1246 		 *    field set to zero (see 5.7.11.3).
1247 		 */
1248 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0);
1249 		ret = 1;
1250 		/*
1251 		 * For 'All Registrants' reservation types, all existing
1252 		 * registrations are still processed as reservation holders
1253 		 * in core_scsi3_pr_seq_non_holder() after the initial
1254 		 * reservation holder is implictly released here.
1255 		 */
1256 	} else if (pr_reg->pr_reg_all_tg_pt &&
1257 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1258 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1259 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1260 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1261 			" UNREGISTER while existing reservation with matching"
1262 			" key 0x%016Lx is present from another SCSI Initiator"
1263 			" Port\n", pr_reg->pr_res_key);
1264 		ret = -EPERM;
1265 	}
1266 	spin_unlock(&dev->dev_reservation_lock);
1267 
1268 	return ret;
1269 }
1270 
1271 /*
1272  * Called with struct t10_reservation->registration_lock held.
1273  */
1274 static void __core_scsi3_free_registration(
1275 	struct se_device *dev,
1276 	struct t10_pr_registration *pr_reg,
1277 	struct list_head *preempt_and_abort_list,
1278 	int dec_holders)
1279 {
1280 	struct target_core_fabric_ops *tfo =
1281 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1282 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1283 	char i_buf[PR_REG_ISID_ID_LEN];
1284 	int prf_isid;
1285 
1286 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1287 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1288 				PR_REG_ISID_ID_LEN);
1289 
1290 	pr_reg->pr_reg_deve->def_pr_registered = 0;
1291 	pr_reg->pr_reg_deve->pr_res_key = 0;
1292 	list_del(&pr_reg->pr_reg_list);
1293 	/*
1294 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1295 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1296 	 */
1297 	if (dec_holders)
1298 		core_scsi3_put_pr_reg(pr_reg);
1299 	/*
1300 	 * Wait until all reference from any other I_T nexuses for this
1301 	 * *pr_reg have been released.  Because list_del() is called above,
1302 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1303 	 * count back to zero, and we release *pr_reg.
1304 	 */
1305 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1306 		spin_unlock(&pr_tmpl->registration_lock);
1307 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1308 				tfo->get_fabric_name());
1309 		cpu_relax();
1310 		spin_lock(&pr_tmpl->registration_lock);
1311 	}
1312 
1313 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1314 		" Node: %s%s\n", tfo->get_fabric_name(),
1315 		pr_reg->pr_reg_nacl->initiatorname,
1316 		(prf_isid) ? &i_buf[0] : "");
1317 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1318 		" Port(s)\n", tfo->get_fabric_name(),
1319 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1320 		dev->transport->name);
1321 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1322 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1323 		pr_reg->pr_res_generation);
1324 
1325 	if (!preempt_and_abort_list) {
1326 		pr_reg->pr_reg_deve = NULL;
1327 		pr_reg->pr_reg_nacl = NULL;
1328 		kfree(pr_reg->pr_aptpl_buf);
1329 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1330 		return;
1331 	}
1332 	/*
1333 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1334 	 * are released once the ABORT_TASK_SET has completed..
1335 	 */
1336 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1337 }
1338 
1339 void core_scsi3_free_pr_reg_from_nacl(
1340 	struct se_device *dev,
1341 	struct se_node_acl *nacl)
1342 {
1343 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1344 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1345 	/*
1346 	 * If the passed se_node_acl matches the reservation holder,
1347 	 * release the reservation.
1348 	 */
1349 	spin_lock(&dev->dev_reservation_lock);
1350 	pr_res_holder = dev->dev_pr_res_holder;
1351 	if ((pr_res_holder != NULL) &&
1352 	    (pr_res_holder->pr_reg_nacl == nacl))
1353 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0);
1354 	spin_unlock(&dev->dev_reservation_lock);
1355 	/*
1356 	 * Release any registration associated with the struct se_node_acl.
1357 	 */
1358 	spin_lock(&pr_tmpl->registration_lock);
1359 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1360 			&pr_tmpl->registration_list, pr_reg_list) {
1361 
1362 		if (pr_reg->pr_reg_nacl != nacl)
1363 			continue;
1364 
1365 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1366 	}
1367 	spin_unlock(&pr_tmpl->registration_lock);
1368 }
1369 
1370 void core_scsi3_free_all_registrations(
1371 	struct se_device *dev)
1372 {
1373 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1374 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1375 
1376 	spin_lock(&dev->dev_reservation_lock);
1377 	pr_res_holder = dev->dev_pr_res_holder;
1378 	if (pr_res_holder != NULL) {
1379 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1380 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1381 				pr_res_holder, 0);
1382 	}
1383 	spin_unlock(&dev->dev_reservation_lock);
1384 
1385 	spin_lock(&pr_tmpl->registration_lock);
1386 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1387 			&pr_tmpl->registration_list, pr_reg_list) {
1388 
1389 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1390 	}
1391 	spin_unlock(&pr_tmpl->registration_lock);
1392 
1393 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1394 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1395 				pr_reg_aptpl_list) {
1396 		list_del(&pr_reg->pr_reg_aptpl_list);
1397 		kfree(pr_reg->pr_aptpl_buf);
1398 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1399 	}
1400 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1401 }
1402 
1403 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1404 {
1405 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1406 			&tpg->tpg_group.cg_item);
1407 }
1408 
1409 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1410 {
1411 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1412 			&tpg->tpg_group.cg_item);
1413 
1414 	atomic_dec(&tpg->tpg_pr_ref_count);
1415 	smp_mb__after_atomic_dec();
1416 }
1417 
1418 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1419 {
1420 	struct se_portal_group *tpg = nacl->se_tpg;
1421 
1422 	if (nacl->dynamic_node_acl)
1423 		return 0;
1424 
1425 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1426 			&nacl->acl_group.cg_item);
1427 }
1428 
1429 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1430 {
1431 	struct se_portal_group *tpg = nacl->se_tpg;
1432 
1433 	if (nacl->dynamic_node_acl) {
1434 		atomic_dec(&nacl->acl_pr_ref_count);
1435 		smp_mb__after_atomic_dec();
1436 		return;
1437 	}
1438 
1439 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1440 			&nacl->acl_group.cg_item);
1441 
1442 	atomic_dec(&nacl->acl_pr_ref_count);
1443 	smp_mb__after_atomic_dec();
1444 }
1445 
1446 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1447 {
1448 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1449 	struct se_node_acl *nacl;
1450 	struct se_portal_group *tpg;
1451 	/*
1452 	 * For nacl->dynamic_node_acl=1
1453 	 */
1454 	if (!lun_acl)
1455 		return 0;
1456 
1457 	nacl = lun_acl->se_lun_nacl;
1458 	tpg = nacl->se_tpg;
1459 
1460 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1461 			&lun_acl->se_lun_group.cg_item);
1462 }
1463 
1464 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1465 {
1466 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1467 	struct se_node_acl *nacl;
1468 	struct se_portal_group *tpg;
1469 	/*
1470 	 * For nacl->dynamic_node_acl=1
1471 	 */
1472 	if (!lun_acl) {
1473 		atomic_dec(&se_deve->pr_ref_count);
1474 		smp_mb__after_atomic_dec();
1475 		return;
1476 	}
1477 	nacl = lun_acl->se_lun_nacl;
1478 	tpg = nacl->se_tpg;
1479 
1480 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1481 			&lun_acl->se_lun_group.cg_item);
1482 
1483 	atomic_dec(&se_deve->pr_ref_count);
1484 	smp_mb__after_atomic_dec();
1485 }
1486 
1487 static int core_scsi3_decode_spec_i_port(
1488 	struct se_cmd *cmd,
1489 	struct se_portal_group *tpg,
1490 	unsigned char *l_isid,
1491 	u64 sa_res_key,
1492 	int all_tg_pt,
1493 	int aptpl)
1494 {
1495 	struct se_device *dev = cmd->se_dev;
1496 	struct se_port *tmp_port;
1497 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1498 	struct se_session *se_sess = cmd->se_sess;
1499 	struct se_node_acl *dest_node_acl = NULL;
1500 	struct se_dev_entry *dest_se_deve = NULL, *local_se_deve;
1501 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1502 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1503 	LIST_HEAD(tid_dest_list);
1504 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1505 	struct target_core_fabric_ops *tmp_tf_ops;
1506 	unsigned char *buf;
1507 	unsigned char *ptr, *i_str = NULL, proto_ident, tmp_proto_ident;
1508 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
1509 	u32 tpdl, tid_len = 0;
1510 	int ret, dest_local_nexus, prf_isid;
1511 	u32 dest_rtpi = 0;
1512 
1513 	memset(dest_iport, 0, 64);
1514 
1515 	local_se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
1516 	/*
1517 	 * Allocate a struct pr_transport_id_holder and setup the
1518 	 * local_node_acl and local_se_deve pointers and add to
1519 	 * struct list_head tid_dest_list for add registration
1520 	 * processing in the loop of tid_dest_list below.
1521 	 */
1522 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1523 	if (!tidh_new) {
1524 		pr_err("Unable to allocate tidh_new\n");
1525 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1526 		return -EINVAL;
1527 	}
1528 	INIT_LIST_HEAD(&tidh_new->dest_list);
1529 	tidh_new->dest_tpg = tpg;
1530 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1531 	tidh_new->dest_se_deve = local_se_deve;
1532 
1533 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1534 				se_sess->se_node_acl, local_se_deve, l_isid,
1535 				sa_res_key, all_tg_pt, aptpl);
1536 	if (!local_pr_reg) {
1537 		kfree(tidh_new);
1538 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1539 		return -ENOMEM;
1540 	}
1541 	tidh_new->dest_pr_reg = local_pr_reg;
1542 	/*
1543 	 * The local I_T nexus does not hold any configfs dependances,
1544 	 * so we set tid_h->dest_local_nexus=1 to prevent the
1545 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1546 	 */
1547 	tidh_new->dest_local_nexus = 1;
1548 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1549 
1550 	buf = transport_kmap_data_sg(cmd);
1551 	/*
1552 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1553 	 * first extract TransportID Parameter Data Length, and make sure
1554 	 * the value matches up to the SCSI expected data transfer length.
1555 	 */
1556 	tpdl = (buf[24] & 0xff) << 24;
1557 	tpdl |= (buf[25] & 0xff) << 16;
1558 	tpdl |= (buf[26] & 0xff) << 8;
1559 	tpdl |= buf[27] & 0xff;
1560 
1561 	if ((tpdl + 28) != cmd->data_length) {
1562 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1563 			" does not equal CDB data_length: %u\n", tpdl,
1564 			cmd->data_length);
1565 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1566 		ret = -EINVAL;
1567 		goto out;
1568 	}
1569 	/*
1570 	 * Start processing the received transport IDs using the
1571 	 * receiving I_T Nexus portal's fabric dependent methods to
1572 	 * obtain the SCSI Initiator Port/Device Identifiers.
1573 	 */
1574 	ptr = &buf[28];
1575 
1576 	while (tpdl > 0) {
1577 		proto_ident = (ptr[0] & 0x0f);
1578 		dest_tpg = NULL;
1579 
1580 		spin_lock(&dev->se_port_lock);
1581 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1582 			tmp_tpg = tmp_port->sep_tpg;
1583 			if (!tmp_tpg)
1584 				continue;
1585 			tmp_tf_ops = tmp_tpg->se_tpg_tfo;
1586 			if (!tmp_tf_ops)
1587 				continue;
1588 			if (!tmp_tf_ops->get_fabric_proto_ident ||
1589 			    !tmp_tf_ops->tpg_parse_pr_out_transport_id)
1590 				continue;
1591 			/*
1592 			 * Look for the matching proto_ident provided by
1593 			 * the received TransportID
1594 			 */
1595 			tmp_proto_ident = tmp_tf_ops->get_fabric_proto_ident(tmp_tpg);
1596 			if (tmp_proto_ident != proto_ident)
1597 				continue;
1598 			dest_rtpi = tmp_port->sep_rtpi;
1599 
1600 			i_str = tmp_tf_ops->tpg_parse_pr_out_transport_id(
1601 					tmp_tpg, (const char *)ptr, &tid_len,
1602 					&iport_ptr);
1603 			if (!i_str)
1604 				continue;
1605 
1606 			atomic_inc(&tmp_tpg->tpg_pr_ref_count);
1607 			smp_mb__after_atomic_inc();
1608 			spin_unlock(&dev->se_port_lock);
1609 
1610 			ret = core_scsi3_tpg_depend_item(tmp_tpg);
1611 			if (ret != 0) {
1612 				pr_err(" core_scsi3_tpg_depend_item()"
1613 					" for tmp_tpg\n");
1614 				atomic_dec(&tmp_tpg->tpg_pr_ref_count);
1615 				smp_mb__after_atomic_dec();
1616 				cmd->scsi_sense_reason =
1617 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1618 				ret = -EINVAL;
1619 				goto out;
1620 			}
1621 			/*
1622 			 * Locate the desination initiator ACL to be registered
1623 			 * from the decoded fabric module specific TransportID
1624 			 * at *i_str.
1625 			 */
1626 			spin_lock_irq(&tmp_tpg->acl_node_lock);
1627 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1628 						tmp_tpg, i_str);
1629 			if (dest_node_acl) {
1630 				atomic_inc(&dest_node_acl->acl_pr_ref_count);
1631 				smp_mb__after_atomic_inc();
1632 			}
1633 			spin_unlock_irq(&tmp_tpg->acl_node_lock);
1634 
1635 			if (!dest_node_acl) {
1636 				core_scsi3_tpg_undepend_item(tmp_tpg);
1637 				spin_lock(&dev->se_port_lock);
1638 				continue;
1639 			}
1640 
1641 			ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
1642 			if (ret != 0) {
1643 				pr_err("configfs_depend_item() failed"
1644 					" for dest_node_acl->acl_group\n");
1645 				atomic_dec(&dest_node_acl->acl_pr_ref_count);
1646 				smp_mb__after_atomic_dec();
1647 				core_scsi3_tpg_undepend_item(tmp_tpg);
1648 				cmd->scsi_sense_reason =
1649 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1650 				ret = -EINVAL;
1651 				goto out;
1652 			}
1653 
1654 			dest_tpg = tmp_tpg;
1655 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1656 				" %s Port RTPI: %hu\n",
1657 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1658 				dest_node_acl->initiatorname, dest_rtpi);
1659 
1660 			spin_lock(&dev->se_port_lock);
1661 			break;
1662 		}
1663 		spin_unlock(&dev->se_port_lock);
1664 
1665 		if (!dest_tpg) {
1666 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1667 					" dest_tpg\n");
1668 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1669 			ret = -EINVAL;
1670 			goto out;
1671 		}
1672 #if 0
1673 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1674 			" tid_len: %d for %s + %s\n",
1675 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1676 			tpdl, tid_len, i_str, iport_ptr);
1677 #endif
1678 		if (tid_len > tpdl) {
1679 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1680 				" %u for Transport ID: %s\n", tid_len, ptr);
1681 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1682 			core_scsi3_tpg_undepend_item(dest_tpg);
1683 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1684 			ret = -EINVAL;
1685 			goto out;
1686 		}
1687 		/*
1688 		 * Locate the desintation struct se_dev_entry pointer for matching
1689 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1690 		 * Target Port.
1691 		 */
1692 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1693 					dest_rtpi);
1694 		if (!dest_se_deve) {
1695 			pr_err("Unable to locate %s dest_se_deve"
1696 				" from destination RTPI: %hu\n",
1697 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1698 				dest_rtpi);
1699 
1700 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1701 			core_scsi3_tpg_undepend_item(dest_tpg);
1702 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1703 			ret = -EINVAL;
1704 			goto out;
1705 		}
1706 
1707 		ret = core_scsi3_lunacl_depend_item(dest_se_deve);
1708 		if (ret < 0) {
1709 			pr_err("core_scsi3_lunacl_depend_item()"
1710 					" failed\n");
1711 			atomic_dec(&dest_se_deve->pr_ref_count);
1712 			smp_mb__after_atomic_dec();
1713 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1714 			core_scsi3_tpg_undepend_item(dest_tpg);
1715 			cmd->scsi_sense_reason =
1716 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1717 			ret = -EINVAL;
1718 			goto out;
1719 		}
1720 #if 0
1721 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1722 			" dest_se_deve mapped_lun: %u\n",
1723 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1724 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1725 #endif
1726 		/*
1727 		 * Skip any TransportIDs that already have a registration for
1728 		 * this target port.
1729 		 */
1730 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1731 					iport_ptr);
1732 		if (pr_reg_e) {
1733 			core_scsi3_put_pr_reg(pr_reg_e);
1734 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1735 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1736 			core_scsi3_tpg_undepend_item(dest_tpg);
1737 			ptr += tid_len;
1738 			tpdl -= tid_len;
1739 			tid_len = 0;
1740 			continue;
1741 		}
1742 		/*
1743 		 * Allocate a struct pr_transport_id_holder and setup
1744 		 * the dest_node_acl and dest_se_deve pointers for the
1745 		 * loop below.
1746 		 */
1747 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1748 				GFP_KERNEL);
1749 		if (!tidh_new) {
1750 			pr_err("Unable to allocate tidh_new\n");
1751 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1752 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1753 			core_scsi3_tpg_undepend_item(dest_tpg);
1754 			cmd->scsi_sense_reason =
1755 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1756 			ret = -ENOMEM;
1757 			goto out;
1758 		}
1759 		INIT_LIST_HEAD(&tidh_new->dest_list);
1760 		tidh_new->dest_tpg = dest_tpg;
1761 		tidh_new->dest_node_acl = dest_node_acl;
1762 		tidh_new->dest_se_deve = dest_se_deve;
1763 
1764 		/*
1765 		 * Allocate, but do NOT add the registration for the
1766 		 * TransportID referenced SCSI Initiator port.  This
1767 		 * done because of the following from spc4r17 in section
1768 		 * 6.14.3 wrt SPEC_I_PT:
1769 		 *
1770 		 * "If a registration fails for any initiator port (e.g., if th
1771 		 * logical unit does not have enough resources available to
1772 		 * hold the registration information), no registrations shall be
1773 		 * made, and the command shall be terminated with
1774 		 * CHECK CONDITION status."
1775 		 *
1776 		 * That means we call __core_scsi3_alloc_registration() here,
1777 		 * and then call __core_scsi3_add_registration() in the
1778 		 * 2nd loop which will never fail.
1779 		 */
1780 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1781 				dest_node_acl, dest_se_deve, iport_ptr,
1782 				sa_res_key, all_tg_pt, aptpl);
1783 		if (!dest_pr_reg) {
1784 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1785 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1786 			core_scsi3_tpg_undepend_item(dest_tpg);
1787 			kfree(tidh_new);
1788 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1789 			ret = -EINVAL;
1790 			goto out;
1791 		}
1792 		tidh_new->dest_pr_reg = dest_pr_reg;
1793 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1794 
1795 		ptr += tid_len;
1796 		tpdl -= tid_len;
1797 		tid_len = 0;
1798 
1799 	}
1800 
1801 	transport_kunmap_data_sg(cmd);
1802 
1803 	/*
1804 	 * Go ahead and create a registrations from tid_dest_list for the
1805 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1806 	 * and dest_se_deve.
1807 	 *
1808 	 * The SA Reservation Key from the PROUT is set for the
1809 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1810 	 * means that the TransportID Initiator port will be
1811 	 * registered on all of the target ports in the SCSI target device
1812 	 * ALL_TG_PT=0 means the registration will only be for the
1813 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1814 	 * was received.
1815 	 */
1816 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1817 		dest_tpg = tidh->dest_tpg;
1818 		dest_node_acl = tidh->dest_node_acl;
1819 		dest_se_deve = tidh->dest_se_deve;
1820 		dest_pr_reg = tidh->dest_pr_reg;
1821 		dest_local_nexus = tidh->dest_local_nexus;
1822 
1823 		list_del(&tidh->dest_list);
1824 		kfree(tidh);
1825 
1826 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1827 		prf_isid = core_pr_dump_initiator_port(dest_pr_reg, &i_buf[0],
1828 						PR_REG_ISID_ID_LEN);
1829 
1830 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1831 					dest_pr_reg, 0, 0);
1832 
1833 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1834 			" registered Transport ID for Node: %s%s Mapped LUN:"
1835 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1836 			dest_node_acl->initiatorname, (prf_isid) ?
1837 			&i_buf[0] : "", dest_se_deve->mapped_lun);
1838 
1839 		if (dest_local_nexus)
1840 			continue;
1841 
1842 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1843 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1844 		core_scsi3_tpg_undepend_item(dest_tpg);
1845 	}
1846 
1847 	return 0;
1848 out:
1849 	transport_kunmap_data_sg(cmd);
1850 	/*
1851 	 * For the failure case, release everything from tid_dest_list
1852 	 * including *dest_pr_reg and the configfs dependances..
1853 	 */
1854 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1855 		dest_tpg = tidh->dest_tpg;
1856 		dest_node_acl = tidh->dest_node_acl;
1857 		dest_se_deve = tidh->dest_se_deve;
1858 		dest_pr_reg = tidh->dest_pr_reg;
1859 		dest_local_nexus = tidh->dest_local_nexus;
1860 
1861 		list_del(&tidh->dest_list);
1862 		kfree(tidh);
1863 		/*
1864 		 * Release any extra ALL_TG_PT=1 registrations for
1865 		 * the SPEC_I_PT=1 case.
1866 		 */
1867 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1868 				&dest_pr_reg->pr_reg_atp_list,
1869 				pr_reg_atp_mem_list) {
1870 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1871 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1872 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1873 		}
1874 
1875 		kfree(dest_pr_reg->pr_aptpl_buf);
1876 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1877 
1878 		if (dest_local_nexus)
1879 			continue;
1880 
1881 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1882 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1883 		core_scsi3_tpg_undepend_item(dest_tpg);
1884 	}
1885 	return ret;
1886 }
1887 
1888 /*
1889  * Called with struct se_device->dev_reservation_lock held
1890  */
1891 static int __core_scsi3_update_aptpl_buf(
1892 	struct se_device *dev,
1893 	unsigned char *buf,
1894 	u32 pr_aptpl_buf_len,
1895 	int clear_aptpl_metadata)
1896 {
1897 	struct se_lun *lun;
1898 	struct se_portal_group *tpg;
1899 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1900 	struct t10_pr_registration *pr_reg;
1901 	unsigned char tmp[512], isid_buf[32];
1902 	ssize_t len = 0;
1903 	int reg_count = 0;
1904 
1905 	memset(buf, 0, pr_aptpl_buf_len);
1906 	/*
1907 	 * Called to clear metadata once APTPL has been deactivated.
1908 	 */
1909 	if (clear_aptpl_metadata) {
1910 		snprintf(buf, pr_aptpl_buf_len,
1911 				"No Registrations or Reservations\n");
1912 		return 0;
1913 	}
1914 	/*
1915 	 * Walk the registration list..
1916 	 */
1917 	spin_lock(&su_dev->t10_pr.registration_lock);
1918 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
1919 			pr_reg_list) {
1920 
1921 		tmp[0] = '\0';
1922 		isid_buf[0] = '\0';
1923 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1924 		lun = pr_reg->pr_reg_tg_pt_lun;
1925 		/*
1926 		 * Write out any ISID value to APTPL metadata that was included
1927 		 * in the original registration.
1928 		 */
1929 		if (pr_reg->isid_present_at_reg)
1930 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1931 					pr_reg->pr_reg_isid);
1932 		/*
1933 		 * Include special metadata if the pr_reg matches the
1934 		 * reservation holder.
1935 		 */
1936 		if (dev->dev_pr_res_holder == pr_reg) {
1937 			snprintf(tmp, 512, "PR_REG_START: %d"
1938 				"\ninitiator_fabric=%s\n"
1939 				"initiator_node=%s\n%s"
1940 				"sa_res_key=%llu\n"
1941 				"res_holder=1\nres_type=%02x\n"
1942 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1943 				"mapped_lun=%u\n", reg_count,
1944 				tpg->se_tpg_tfo->get_fabric_name(),
1945 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1946 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1947 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1948 				pr_reg->pr_res_mapped_lun);
1949 		} else {
1950 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1951 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1952 				"sa_res_key=%llu\nres_holder=0\n"
1953 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1954 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1955 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1956 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1957 				pr_reg->pr_res_mapped_lun);
1958 		}
1959 
1960 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1961 			pr_err("Unable to update renaming"
1962 				" APTPL metadata\n");
1963 			spin_unlock(&su_dev->t10_pr.registration_lock);
1964 			return -EMSGSIZE;
1965 		}
1966 		len += sprintf(buf+len, "%s", tmp);
1967 
1968 		/*
1969 		 * Include information about the associated SCSI target port.
1970 		 */
1971 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1972 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1973 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1974 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1975 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1976 			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);
1977 
1978 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1979 			pr_err("Unable to update renaming"
1980 				" APTPL metadata\n");
1981 			spin_unlock(&su_dev->t10_pr.registration_lock);
1982 			return -EMSGSIZE;
1983 		}
1984 		len += sprintf(buf+len, "%s", tmp);
1985 		reg_count++;
1986 	}
1987 	spin_unlock(&su_dev->t10_pr.registration_lock);
1988 
1989 	if (!reg_count)
1990 		len += sprintf(buf+len, "No Registrations or Reservations");
1991 
1992 	return 0;
1993 }
1994 
1995 static int core_scsi3_update_aptpl_buf(
1996 	struct se_device *dev,
1997 	unsigned char *buf,
1998 	u32 pr_aptpl_buf_len,
1999 	int clear_aptpl_metadata)
2000 {
2001 	int ret;
2002 
2003 	spin_lock(&dev->dev_reservation_lock);
2004 	ret = __core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
2005 				clear_aptpl_metadata);
2006 	spin_unlock(&dev->dev_reservation_lock);
2007 
2008 	return ret;
2009 }
2010 
2011 /*
2012  * Called with struct se_device->aptpl_file_mutex held
2013  */
2014 static int __core_scsi3_write_aptpl_to_file(
2015 	struct se_device *dev,
2016 	unsigned char *buf,
2017 	u32 pr_aptpl_buf_len)
2018 {
2019 	struct t10_wwn *wwn = &dev->se_sub_dev->t10_wwn;
2020 	struct file *file;
2021 	struct iovec iov[1];
2022 	mm_segment_t old_fs;
2023 	int flags = O_RDWR | O_CREAT | O_TRUNC;
2024 	char path[512];
2025 	int ret;
2026 
2027 	memset(iov, 0, sizeof(struct iovec));
2028 	memset(path, 0, 512);
2029 
2030 	if (strlen(&wwn->unit_serial[0]) >= 512) {
2031 		pr_err("WWN value for struct se_device does not fit"
2032 			" into path buffer\n");
2033 		return -EMSGSIZE;
2034 	}
2035 
2036 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
2037 	file = filp_open(path, flags, 0600);
2038 	if (IS_ERR(file) || !file || !file->f_dentry) {
2039 		pr_err("filp_open(%s) for APTPL metadata"
2040 			" failed\n", path);
2041 		return (PTR_ERR(file) < 0 ? PTR_ERR(file) : -ENOENT);
2042 	}
2043 
2044 	iov[0].iov_base = &buf[0];
2045 	if (!pr_aptpl_buf_len)
2046 		iov[0].iov_len = (strlen(&buf[0]) + 1); /* Add extra for NULL */
2047 	else
2048 		iov[0].iov_len = pr_aptpl_buf_len;
2049 
2050 	old_fs = get_fs();
2051 	set_fs(get_ds());
2052 	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
2053 	set_fs(old_fs);
2054 
2055 	if (ret < 0) {
2056 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2057 		filp_close(file, NULL);
2058 		return -EIO;
2059 	}
2060 	filp_close(file, NULL);
2061 
2062 	return 0;
2063 }
2064 
2065 static int core_scsi3_update_and_write_aptpl(
2066 	struct se_device *dev,
2067 	unsigned char *in_buf,
2068 	u32 in_pr_aptpl_buf_len)
2069 {
2070 	unsigned char null_buf[64], *buf;
2071 	u32 pr_aptpl_buf_len;
2072 	int ret, clear_aptpl_metadata = 0;
2073 	/*
2074 	 * Can be called with a NULL pointer from PROUT service action CLEAR
2075 	 */
2076 	if (!in_buf) {
2077 		memset(null_buf, 0, 64);
2078 		buf = &null_buf[0];
2079 		/*
2080 		 * This will clear the APTPL metadata to:
2081 		 * "No Registrations or Reservations" status
2082 		 */
2083 		pr_aptpl_buf_len = 64;
2084 		clear_aptpl_metadata = 1;
2085 	} else {
2086 		buf = in_buf;
2087 		pr_aptpl_buf_len = in_pr_aptpl_buf_len;
2088 	}
2089 
2090 	ret = core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
2091 				clear_aptpl_metadata);
2092 	if (ret != 0)
2093 		return ret;
2094 	/*
2095 	 * __core_scsi3_write_aptpl_to_file() will call strlen()
2096 	 * on the passed buf to determine pr_aptpl_buf_len.
2097 	 */
2098 	ret = __core_scsi3_write_aptpl_to_file(dev, buf, 0);
2099 	if (ret != 0)
2100 		return ret;
2101 
2102 	return ret;
2103 }
2104 
2105 static int core_scsi3_emulate_pro_register(
2106 	struct se_cmd *cmd,
2107 	u64 res_key,
2108 	u64 sa_res_key,
2109 	int aptpl,
2110 	int all_tg_pt,
2111 	int spec_i_pt,
2112 	int ignore_key)
2113 {
2114 	struct se_session *se_sess = cmd->se_sess;
2115 	struct se_device *dev = cmd->se_dev;
2116 	struct se_dev_entry *se_deve;
2117 	struct se_lun *se_lun = cmd->se_lun;
2118 	struct se_portal_group *se_tpg;
2119 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp, *pr_reg_e;
2120 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2121 	/* Used for APTPL metadata w/ UNREGISTER */
2122 	unsigned char *pr_aptpl_buf = NULL;
2123 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2124 	int pr_holder = 0, ret = 0, type;
2125 
2126 	if (!se_sess || !se_lun) {
2127 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2128 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2129 		return -EINVAL;
2130 	}
2131 	se_tpg = se_sess->se_tpg;
2132 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2133 
2134 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2135 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2136 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2137 				PR_REG_ISID_LEN);
2138 		isid_ptr = &isid_buf[0];
2139 	}
2140 	/*
2141 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2142 	 */
2143 	pr_reg_e = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2144 	if (!pr_reg_e) {
2145 		if (res_key) {
2146 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2147 				" for SA REGISTER, returning CONFLICT\n");
2148 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2149 			return -EINVAL;
2150 		}
2151 		/*
2152 		 * Do nothing but return GOOD status.
2153 		 */
2154 		if (!sa_res_key)
2155 			return 0;
2156 
2157 		if (!spec_i_pt) {
2158 			/*
2159 			 * Perform the Service Action REGISTER on the Initiator
2160 			 * Port Endpoint that the PRO was received from on the
2161 			 * Logical Unit of the SCSI device server.
2162 			 */
2163 			ret = core_scsi3_alloc_registration(cmd->se_dev,
2164 					se_sess->se_node_acl, se_deve, isid_ptr,
2165 					sa_res_key, all_tg_pt, aptpl,
2166 					ignore_key, 0);
2167 			if (ret != 0) {
2168 				pr_err("Unable to allocate"
2169 					" struct t10_pr_registration\n");
2170 				cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
2171 				return -EINVAL;
2172 			}
2173 		} else {
2174 			/*
2175 			 * Register both the Initiator port that received
2176 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2177 			 * TransportID from Parameter list and loop through
2178 			 * fabric dependent parameter list while calling
2179 			 * logic from of core_scsi3_alloc_registration() for
2180 			 * each TransportID provided SCSI Initiator Port/Device
2181 			 */
2182 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2183 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2184 			if (ret != 0)
2185 				return ret;
2186 		}
2187 		/*
2188 		 * Nothing left to do for the APTPL=0 case.
2189 		 */
2190 		if (!aptpl) {
2191 			pr_tmpl->pr_aptpl_active = 0;
2192 			core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2193 			pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
2194 					" REGISTER\n");
2195 			return 0;
2196 		}
2197 		/*
2198 		 * Locate the newly allocated local I_T Nexus *pr_reg, and
2199 		 * update the APTPL metadata information using its
2200 		 * preallocated *pr_reg->pr_aptpl_buf.
2201 		 */
2202 		pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev,
2203 				se_sess->se_node_acl, se_sess);
2204 
2205 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2206 				&pr_reg->pr_aptpl_buf[0],
2207 				pr_tmpl->pr_aptpl_buf_len);
2208 		if (!ret) {
2209 			pr_tmpl->pr_aptpl_active = 1;
2210 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for REGISTER\n");
2211 		}
2212 
2213 		core_scsi3_put_pr_reg(pr_reg);
2214 		return ret;
2215 	} else {
2216 		/*
2217 		 * Locate the existing *pr_reg via struct se_node_acl pointers
2218 		 */
2219 		pr_reg = pr_reg_e;
2220 		type = pr_reg->pr_res_type;
2221 
2222 		if (!ignore_key) {
2223 			if (res_key != pr_reg->pr_res_key) {
2224 				pr_err("SPC-3 PR REGISTER: Received"
2225 					" res_key: 0x%016Lx does not match"
2226 					" existing SA REGISTER res_key:"
2227 					" 0x%016Lx\n", res_key,
2228 					pr_reg->pr_res_key);
2229 				core_scsi3_put_pr_reg(pr_reg);
2230 				cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2231 				return -EINVAL;
2232 			}
2233 		}
2234 		if (spec_i_pt) {
2235 			pr_err("SPC-3 PR UNREGISTER: SPEC_I_PT"
2236 				" set while sa_res_key=0\n");
2237 			core_scsi3_put_pr_reg(pr_reg);
2238 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
2239 			return -EINVAL;
2240 		}
2241 		/*
2242 		 * An existing ALL_TG_PT=1 registration being released
2243 		 * must also set ALL_TG_PT=1 in the incoming PROUT.
2244 		 */
2245 		if (pr_reg->pr_reg_all_tg_pt && !(all_tg_pt)) {
2246 			pr_err("SPC-3 PR UNREGISTER: ALL_TG_PT=1"
2247 				" registration exists, but ALL_TG_PT=1 bit not"
2248 				" present in received PROUT\n");
2249 			core_scsi3_put_pr_reg(pr_reg);
2250 			cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2251 			return -EINVAL;
2252 		}
2253 		/*
2254 		 * Allocate APTPL metadata buffer used for UNREGISTER ops
2255 		 */
2256 		if (aptpl) {
2257 			pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len,
2258 						GFP_KERNEL);
2259 			if (!pr_aptpl_buf) {
2260 				pr_err("Unable to allocate"
2261 					" pr_aptpl_buf\n");
2262 				core_scsi3_put_pr_reg(pr_reg);
2263 				cmd->scsi_sense_reason =
2264 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2265 				return -EINVAL;
2266 			}
2267 		}
2268 		/*
2269 		 * sa_res_key=0 Unregister Reservation Key for registered I_T
2270 		 * Nexus sa_res_key=1 Change Reservation Key for registered I_T
2271 		 * Nexus.
2272 		 */
2273 		if (!sa_res_key) {
2274 			pr_holder = core_scsi3_check_implict_release(
2275 					cmd->se_dev, pr_reg);
2276 			if (pr_holder < 0) {
2277 				kfree(pr_aptpl_buf);
2278 				core_scsi3_put_pr_reg(pr_reg);
2279 				cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2280 				return -EINVAL;
2281 			}
2282 
2283 			spin_lock(&pr_tmpl->registration_lock);
2284 			/*
2285 			 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2286 			 * and matching pr_res_key.
2287 			 */
2288 			if (pr_reg->pr_reg_all_tg_pt) {
2289 				list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2290 						&pr_tmpl->registration_list,
2291 						pr_reg_list) {
2292 
2293 					if (!pr_reg_p->pr_reg_all_tg_pt)
2294 						continue;
2295 
2296 					if (pr_reg_p->pr_res_key != res_key)
2297 						continue;
2298 
2299 					if (pr_reg == pr_reg_p)
2300 						continue;
2301 
2302 					if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2303 						   pr_reg_p->pr_reg_nacl->initiatorname))
2304 						continue;
2305 
2306 					__core_scsi3_free_registration(dev,
2307 							pr_reg_p, NULL, 0);
2308 				}
2309 			}
2310 			/*
2311 			 * Release the calling I_T Nexus registration now..
2312 			 */
2313 			__core_scsi3_free_registration(cmd->se_dev, pr_reg,
2314 							NULL, 1);
2315 			/*
2316 			 * From spc4r17, section 5.7.11.3 Unregistering
2317 			 *
2318 			 * If the persistent reservation is a registrants only
2319 			 * type, the device server shall establish a unit
2320 			 * attention condition for the initiator port associated
2321 			 * with every registered I_T nexus except for the I_T
2322 			 * nexus on which the PERSISTENT RESERVE OUT command was
2323 			 * received, with the additional sense code set to
2324 			 * RESERVATIONS RELEASED.
2325 			 */
2326 			if (pr_holder &&
2327 			   ((type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
2328 			    (type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY))) {
2329 				list_for_each_entry(pr_reg_p,
2330 						&pr_tmpl->registration_list,
2331 						pr_reg_list) {
2332 
2333 					core_scsi3_ua_allocate(
2334 						pr_reg_p->pr_reg_nacl,
2335 						pr_reg_p->pr_res_mapped_lun,
2336 						0x2A,
2337 						ASCQ_2AH_RESERVATIONS_RELEASED);
2338 				}
2339 			}
2340 			spin_unlock(&pr_tmpl->registration_lock);
2341 
2342 			if (!aptpl) {
2343 				pr_tmpl->pr_aptpl_active = 0;
2344 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2345 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2346 						" for UNREGISTER\n");
2347 				return 0;
2348 			}
2349 
2350 			ret = core_scsi3_update_and_write_aptpl(dev,
2351 					&pr_aptpl_buf[0],
2352 					pr_tmpl->pr_aptpl_buf_len);
2353 			if (!ret) {
2354 				pr_tmpl->pr_aptpl_active = 1;
2355 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2356 						" for UNREGISTER\n");
2357 			}
2358 
2359 			kfree(pr_aptpl_buf);
2360 			return ret;
2361 		} else {
2362 			/*
2363 			 * Increment PRgeneration counter for struct se_device"
2364 			 * upon a successful REGISTER, see spc4r17 section 6.3.2
2365 			 * READ_KEYS service action.
2366 			 */
2367 			pr_reg->pr_res_generation = core_scsi3_pr_generation(
2368 							cmd->se_dev);
2369 			pr_reg->pr_res_key = sa_res_key;
2370 			pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2371 				" Key for %s to: 0x%016Lx PRgeneration:"
2372 				" 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2373 				(ignore_key) ? "_AND_IGNORE_EXISTING_KEY" : "",
2374 				pr_reg->pr_reg_nacl->initiatorname,
2375 				pr_reg->pr_res_key, pr_reg->pr_res_generation);
2376 
2377 			if (!aptpl) {
2378 				pr_tmpl->pr_aptpl_active = 0;
2379 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2380 				core_scsi3_put_pr_reg(pr_reg);
2381 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2382 						" for REGISTER\n");
2383 				return 0;
2384 			}
2385 
2386 			ret = core_scsi3_update_and_write_aptpl(dev,
2387 					&pr_aptpl_buf[0],
2388 					pr_tmpl->pr_aptpl_buf_len);
2389 			if (!ret) {
2390 				pr_tmpl->pr_aptpl_active = 1;
2391 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2392 						" for REGISTER\n");
2393 			}
2394 
2395 			kfree(pr_aptpl_buf);
2396 			core_scsi3_put_pr_reg(pr_reg);
2397 		}
2398 	}
2399 	return 0;
2400 }
2401 
2402 unsigned char *core_scsi3_pr_dump_type(int type)
2403 {
2404 	switch (type) {
2405 	case PR_TYPE_WRITE_EXCLUSIVE:
2406 		return "Write Exclusive Access";
2407 	case PR_TYPE_EXCLUSIVE_ACCESS:
2408 		return "Exclusive Access";
2409 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2410 		return "Write Exclusive Access, Registrants Only";
2411 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2412 		return "Exclusive Access, Registrants Only";
2413 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2414 		return "Write Exclusive Access, All Registrants";
2415 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2416 		return "Exclusive Access, All Registrants";
2417 	default:
2418 		break;
2419 	}
2420 
2421 	return "Unknown SPC-3 PR Type";
2422 }
2423 
2424 static int core_scsi3_pro_reserve(
2425 	struct se_cmd *cmd,
2426 	struct se_device *dev,
2427 	int type,
2428 	int scope,
2429 	u64 res_key)
2430 {
2431 	struct se_session *se_sess = cmd->se_sess;
2432 	struct se_lun *se_lun = cmd->se_lun;
2433 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2434 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2435 	char i_buf[PR_REG_ISID_ID_LEN];
2436 	int ret, prf_isid;
2437 
2438 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2439 
2440 	if (!se_sess || !se_lun) {
2441 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2442 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2443 		return -EINVAL;
2444 	}
2445 	/*
2446 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2447 	 */
2448 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2449 				se_sess);
2450 	if (!pr_reg) {
2451 		pr_err("SPC-3 PR: Unable to locate"
2452 			" PR_REGISTERED *pr_reg for RESERVE\n");
2453 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2454 		return -EINVAL;
2455 	}
2456 	/*
2457 	 * From spc4r17 Section 5.7.9: Reserving:
2458 	 *
2459 	 * An application client creates a persistent reservation by issuing
2460 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2461 	 * a registered I_T nexus with the following parameters:
2462 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2463 	 * 	 registered with the logical unit for the I_T nexus; and
2464 	 */
2465 	if (res_key != pr_reg->pr_res_key) {
2466 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2467 			" does not match existing SA REGISTER res_key:"
2468 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2469 		core_scsi3_put_pr_reg(pr_reg);
2470 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2471 		return -EINVAL;
2472 	}
2473 	/*
2474 	 * From spc4r17 Section 5.7.9: Reserving:
2475 	 *
2476 	 * From above:
2477 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2478 	 *     being created.
2479 	 *
2480 	 * Only one persistent reservation is allowed at a time per logical unit
2481 	 * and that persistent reservation has a scope of LU_SCOPE.
2482 	 */
2483 	if (scope != PR_SCOPE_LU_SCOPE) {
2484 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2485 		core_scsi3_put_pr_reg(pr_reg);
2486 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
2487 		return -EINVAL;
2488 	}
2489 	/*
2490 	 * See if we have an existing PR reservation holder pointer at
2491 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2492 	 * *pr_res_holder.
2493 	 */
2494 	spin_lock(&dev->dev_reservation_lock);
2495 	pr_res_holder = dev->dev_pr_res_holder;
2496 	if ((pr_res_holder)) {
2497 		/*
2498 		 * From spc4r17 Section 5.7.9: Reserving:
2499 		 *
2500 		 * If the device server receives a PERSISTENT RESERVE OUT
2501 		 * command from an I_T nexus other than a persistent reservation
2502 		 * holder (see 5.7.10) that attempts to create a persistent
2503 		 * reservation when a persistent reservation already exists for
2504 		 * the logical unit, then the command shall be completed with
2505 		 * RESERVATION CONFLICT status.
2506 		 */
2507 		if (pr_res_holder != pr_reg) {
2508 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2509 			pr_err("SPC-3 PR: Attempted RESERVE from"
2510 				" [%s]: %s while reservation already held by"
2511 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2512 				cmd->se_tfo->get_fabric_name(),
2513 				se_sess->se_node_acl->initiatorname,
2514 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2515 				pr_res_holder->pr_reg_nacl->initiatorname);
2516 
2517 			spin_unlock(&dev->dev_reservation_lock);
2518 			core_scsi3_put_pr_reg(pr_reg);
2519 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2520 			return -EINVAL;
2521 		}
2522 		/*
2523 		 * From spc4r17 Section 5.7.9: Reserving:
2524 		 *
2525 		 * If a persistent reservation holder attempts to modify the
2526 		 * type or scope of an existing persistent reservation, the
2527 		 * command shall be completed with RESERVATION CONFLICT status.
2528 		 */
2529 		if ((pr_res_holder->pr_res_type != type) ||
2530 		    (pr_res_holder->pr_res_scope != scope)) {
2531 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2532 			pr_err("SPC-3 PR: Attempted RESERVE from"
2533 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2534 				" while reservation already held by [%s]: %s,"
2535 				" returning RESERVATION_CONFLICT\n",
2536 				cmd->se_tfo->get_fabric_name(),
2537 				se_sess->se_node_acl->initiatorname,
2538 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2539 				pr_res_holder->pr_reg_nacl->initiatorname);
2540 
2541 			spin_unlock(&dev->dev_reservation_lock);
2542 			core_scsi3_put_pr_reg(pr_reg);
2543 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2544 			return -EINVAL;
2545 		}
2546 		/*
2547 		 * From spc4r17 Section 5.7.9: Reserving:
2548 		 *
2549 		 * If the device server receives a PERSISTENT RESERVE OUT
2550 		 * command with RESERVE service action where the TYPE field and
2551 		 * the SCOPE field contain the same values as the existing type
2552 		 * and scope from a persistent reservation holder, it shall not
2553 		 * make any change to the existing persistent reservation and
2554 		 * shall completethe command with GOOD status.
2555 		 */
2556 		spin_unlock(&dev->dev_reservation_lock);
2557 		core_scsi3_put_pr_reg(pr_reg);
2558 		return 0;
2559 	}
2560 	/*
2561 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2562 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2563 	 */
2564 	pr_reg->pr_res_scope = scope;
2565 	pr_reg->pr_res_type = type;
2566 	pr_reg->pr_res_holder = 1;
2567 	dev->dev_pr_res_holder = pr_reg;
2568 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2569 				PR_REG_ISID_ID_LEN);
2570 
2571 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2572 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2573 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2574 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2575 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2576 			cmd->se_tfo->get_fabric_name(),
2577 			se_sess->se_node_acl->initiatorname,
2578 			(prf_isid) ? &i_buf[0] : "");
2579 	spin_unlock(&dev->dev_reservation_lock);
2580 
2581 	if (pr_tmpl->pr_aptpl_active) {
2582 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2583 				&pr_reg->pr_aptpl_buf[0],
2584 				pr_tmpl->pr_aptpl_buf_len);
2585 		if (!ret)
2586 			pr_debug("SPC-3 PR: Updated APTPL metadata"
2587 					" for RESERVE\n");
2588 	}
2589 
2590 	core_scsi3_put_pr_reg(pr_reg);
2591 	return 0;
2592 }
2593 
2594 static int core_scsi3_emulate_pro_reserve(
2595 	struct se_cmd *cmd,
2596 	int type,
2597 	int scope,
2598 	u64 res_key)
2599 {
2600 	struct se_device *dev = cmd->se_dev;
2601 	int ret = 0;
2602 
2603 	switch (type) {
2604 	case PR_TYPE_WRITE_EXCLUSIVE:
2605 	case PR_TYPE_EXCLUSIVE_ACCESS:
2606 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2607 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2608 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2609 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2610 		ret = core_scsi3_pro_reserve(cmd, dev, type, scope, res_key);
2611 		break;
2612 	default:
2613 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2614 			" 0x%02x\n", type);
2615 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2616 		return -EINVAL;
2617 	}
2618 
2619 	return ret;
2620 }
2621 
2622 /*
2623  * Called with struct se_device->dev_reservation_lock held.
2624  */
2625 static void __core_scsi3_complete_pro_release(
2626 	struct se_device *dev,
2627 	struct se_node_acl *se_nacl,
2628 	struct t10_pr_registration *pr_reg,
2629 	int explict)
2630 {
2631 	struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2632 	char i_buf[PR_REG_ISID_ID_LEN];
2633 	int prf_isid;
2634 
2635 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2636 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2637 				PR_REG_ISID_ID_LEN);
2638 	/*
2639 	 * Go ahead and release the current PR reservation holder.
2640 	 */
2641 	dev->dev_pr_res_holder = NULL;
2642 
2643 	pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2644 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2645 		tfo->get_fabric_name(), (explict) ? "explict" : "implict",
2646 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
2647 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2648 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2649 		tfo->get_fabric_name(), se_nacl->initiatorname,
2650 		(prf_isid) ? &i_buf[0] : "");
2651 	/*
2652 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2653 	 */
2654 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2655 }
2656 
2657 static int core_scsi3_emulate_pro_release(
2658 	struct se_cmd *cmd,
2659 	int type,
2660 	int scope,
2661 	u64 res_key)
2662 {
2663 	struct se_device *dev = cmd->se_dev;
2664 	struct se_session *se_sess = cmd->se_sess;
2665 	struct se_lun *se_lun = cmd->se_lun;
2666 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2667 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2668 	int ret, all_reg = 0;
2669 
2670 	if (!se_sess || !se_lun) {
2671 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2672 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2673 		return -EINVAL;
2674 	}
2675 	/*
2676 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2677 	 */
2678 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2679 	if (!pr_reg) {
2680 		pr_err("SPC-3 PR: Unable to locate"
2681 			" PR_REGISTERED *pr_reg for RELEASE\n");
2682 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2683 		return -EINVAL;
2684 	}
2685 	/*
2686 	 * From spc4r17 Section 5.7.11.2 Releasing:
2687 	 *
2688 	 * If there is no persistent reservation or in response to a persistent
2689 	 * reservation release request from a registered I_T nexus that is not a
2690 	 * persistent reservation holder (see 5.7.10), the device server shall
2691 	 * do the following:
2692 	 *
2693 	 *     a) Not release the persistent reservation, if any;
2694 	 *     b) Not remove any registrations; and
2695 	 *     c) Complete the command with GOOD status.
2696 	 */
2697 	spin_lock(&dev->dev_reservation_lock);
2698 	pr_res_holder = dev->dev_pr_res_holder;
2699 	if (!pr_res_holder) {
2700 		/*
2701 		 * No persistent reservation, return GOOD status.
2702 		 */
2703 		spin_unlock(&dev->dev_reservation_lock);
2704 		core_scsi3_put_pr_reg(pr_reg);
2705 		return 0;
2706 	}
2707 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2708 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
2709 		all_reg = 1;
2710 
2711 	if ((all_reg == 0) && (pr_res_holder != pr_reg)) {
2712 		/*
2713 		 * Non 'All Registrants' PR Type cases..
2714 		 * Release request from a registered I_T nexus that is not a
2715 		 * persistent reservation holder. return GOOD status.
2716 		 */
2717 		spin_unlock(&dev->dev_reservation_lock);
2718 		core_scsi3_put_pr_reg(pr_reg);
2719 		return 0;
2720 	}
2721 	/*
2722 	 * From spc4r17 Section 5.7.11.2 Releasing:
2723 	 *
2724 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2725 	 * release a persistent reservation.
2726 	 *
2727 	 * An application client releases the persistent reservation by issuing
2728 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2729 	 * an I_T nexus that is a persistent reservation holder with the
2730 	 * following parameters:
2731 	 *
2732 	 *     a) RESERVATION KEY field set to the value of the reservation key
2733 	 *	  that is registered with the logical unit for the I_T nexus;
2734 	 */
2735 	if (res_key != pr_reg->pr_res_key) {
2736 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2737 			" does not match existing SA REGISTER res_key:"
2738 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2739 		spin_unlock(&dev->dev_reservation_lock);
2740 		core_scsi3_put_pr_reg(pr_reg);
2741 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2742 		return -EINVAL;
2743 	}
2744 	/*
2745 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2746 	 *
2747 	 * b) TYPE field and SCOPE field set to match the persistent
2748 	 *    reservation being released.
2749 	 */
2750 	if ((pr_res_holder->pr_res_type != type) ||
2751 	    (pr_res_holder->pr_res_scope != scope)) {
2752 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2753 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2754 			" reservation from [%s]: %s with different TYPE "
2755 			"and/or SCOPE  while reservation already held by"
2756 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2757 			cmd->se_tfo->get_fabric_name(),
2758 			se_sess->se_node_acl->initiatorname,
2759 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2760 			pr_res_holder->pr_reg_nacl->initiatorname);
2761 
2762 		spin_unlock(&dev->dev_reservation_lock);
2763 		core_scsi3_put_pr_reg(pr_reg);
2764 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2765 		return -EINVAL;
2766 	}
2767 	/*
2768 	 * In response to a persistent reservation release request from the
2769 	 * persistent reservation holder the device server shall perform a
2770 	 * release by doing the following as an uninterrupted series of actions:
2771 	 * a) Release the persistent reservation;
2772 	 * b) Not remove any registration(s);
2773 	 * c) If the released persistent reservation is a registrants only type
2774 	 * or all registrants type persistent reservation,
2775 	 *    the device server shall establish a unit attention condition for
2776 	 *    the initiator port associated with every regis-
2777 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2778 	 *    RESERVE OUT command with RELEASE service action was received,
2779 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2780 	 * d) If the persistent reservation is of any other type, the device
2781 	 *    server shall not establish a unit attention condition.
2782 	 */
2783 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2784 			pr_reg, 1);
2785 
2786 	spin_unlock(&dev->dev_reservation_lock);
2787 
2788 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2789 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2790 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2791 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2792 		/*
2793 		 * If no UNIT ATTENTION conditions will be established for
2794 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2795 		 * go ahead and check for APTPL=1 update+write below
2796 		 */
2797 		goto write_aptpl;
2798 	}
2799 
2800 	spin_lock(&pr_tmpl->registration_lock);
2801 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2802 			pr_reg_list) {
2803 		/*
2804 		 * Do not establish a UNIT ATTENTION condition
2805 		 * for the calling I_T Nexus
2806 		 */
2807 		if (pr_reg_p == pr_reg)
2808 			continue;
2809 
2810 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2811 				pr_reg_p->pr_res_mapped_lun,
2812 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2813 	}
2814 	spin_unlock(&pr_tmpl->registration_lock);
2815 
2816 write_aptpl:
2817 	if (pr_tmpl->pr_aptpl_active) {
2818 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2819 				&pr_reg->pr_aptpl_buf[0],
2820 				pr_tmpl->pr_aptpl_buf_len);
2821 		if (!ret)
2822 			pr_debug("SPC-3 PR: Updated APTPL metadata for RELEASE\n");
2823 	}
2824 
2825 	core_scsi3_put_pr_reg(pr_reg);
2826 	return 0;
2827 }
2828 
2829 static int core_scsi3_emulate_pro_clear(
2830 	struct se_cmd *cmd,
2831 	u64 res_key)
2832 {
2833 	struct se_device *dev = cmd->se_dev;
2834 	struct se_node_acl *pr_reg_nacl;
2835 	struct se_session *se_sess = cmd->se_sess;
2836 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2837 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2838 	u32 pr_res_mapped_lun = 0;
2839 	int calling_it_nexus = 0;
2840 	/*
2841 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2842 	 */
2843 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2844 			se_sess->se_node_acl, se_sess);
2845 	if (!pr_reg_n) {
2846 		pr_err("SPC-3 PR: Unable to locate"
2847 			" PR_REGISTERED *pr_reg for CLEAR\n");
2848 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2849 		return -EINVAL;
2850 	}
2851 	/*
2852 	 * From spc4r17 section 5.7.11.6, Clearing:
2853 	 *
2854 	 * Any application client may release the persistent reservation and
2855 	 * remove all registrations from a device server by issuing a
2856 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2857 	 * registered I_T nexus with the following parameter:
2858 	 *
2859 	 *	a) RESERVATION KEY field set to the value of the reservation key
2860 	 * 	   that is registered with the logical unit for the I_T nexus.
2861 	 */
2862 	if (res_key != pr_reg_n->pr_res_key) {
2863 		pr_err("SPC-3 PR REGISTER: Received"
2864 			" res_key: 0x%016Lx does not match"
2865 			" existing SA REGISTER res_key:"
2866 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2867 		core_scsi3_put_pr_reg(pr_reg_n);
2868 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2869 		return -EINVAL;
2870 	}
2871 	/*
2872 	 * a) Release the persistent reservation, if any;
2873 	 */
2874 	spin_lock(&dev->dev_reservation_lock);
2875 	pr_res_holder = dev->dev_pr_res_holder;
2876 	if (pr_res_holder) {
2877 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2878 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2879 			pr_res_holder, 0);
2880 	}
2881 	spin_unlock(&dev->dev_reservation_lock);
2882 	/*
2883 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2884 	 */
2885 	spin_lock(&pr_tmpl->registration_lock);
2886 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2887 			&pr_tmpl->registration_list, pr_reg_list) {
2888 
2889 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2890 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2891 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2892 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2893 					calling_it_nexus);
2894 		/*
2895 		 * e) Establish a unit attention condition for the initiator
2896 		 *    port associated with every registered I_T nexus other
2897 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2898 		 *    command with CLEAR service action was received, with the
2899 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2900 		 */
2901 		if (!calling_it_nexus)
2902 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2903 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2904 	}
2905 	spin_unlock(&pr_tmpl->registration_lock);
2906 
2907 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2908 		cmd->se_tfo->get_fabric_name());
2909 
2910 	if (pr_tmpl->pr_aptpl_active) {
2911 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2912 		pr_debug("SPC-3 PR: Updated APTPL metadata"
2913 				" for CLEAR\n");
2914 	}
2915 
2916 	core_scsi3_pr_generation(dev);
2917 	return 0;
2918 }
2919 
2920 /*
2921  * Called with struct se_device->dev_reservation_lock held.
2922  */
2923 static void __core_scsi3_complete_pro_preempt(
2924 	struct se_device *dev,
2925 	struct t10_pr_registration *pr_reg,
2926 	struct list_head *preempt_and_abort_list,
2927 	int type,
2928 	int scope,
2929 	int abort)
2930 {
2931 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2932 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2933 	char i_buf[PR_REG_ISID_ID_LEN];
2934 	int prf_isid;
2935 
2936 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2937 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2938 				PR_REG_ISID_ID_LEN);
2939 	/*
2940 	 * Do an implict RELEASE of the existing reservation.
2941 	 */
2942 	if (dev->dev_pr_res_holder)
2943 		__core_scsi3_complete_pro_release(dev, nacl,
2944 				dev->dev_pr_res_holder, 0);
2945 
2946 	dev->dev_pr_res_holder = pr_reg;
2947 	pr_reg->pr_res_holder = 1;
2948 	pr_reg->pr_res_type = type;
2949 	pr_reg->pr_res_scope = scope;
2950 
2951 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2952 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2953 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2954 		core_scsi3_pr_dump_type(type),
2955 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2956 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2957 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2958 		nacl->initiatorname, (prf_isid) ? &i_buf[0] : "");
2959 	/*
2960 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2961 	 * struct t10_pr_registration to the list that will be compared
2962 	 * against received CDBs..
2963 	 */
2964 	if (preempt_and_abort_list)
2965 		list_add_tail(&pr_reg->pr_reg_abort_list,
2966 				preempt_and_abort_list);
2967 }
2968 
2969 static void core_scsi3_release_preempt_and_abort(
2970 	struct list_head *preempt_and_abort_list,
2971 	struct t10_pr_registration *pr_reg_holder)
2972 {
2973 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2974 
2975 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2976 				pr_reg_abort_list) {
2977 
2978 		list_del(&pr_reg->pr_reg_abort_list);
2979 		if (pr_reg_holder == pr_reg)
2980 			continue;
2981 		if (pr_reg->pr_res_holder) {
2982 			pr_warn("pr_reg->pr_res_holder still set\n");
2983 			continue;
2984 		}
2985 
2986 		pr_reg->pr_reg_deve = NULL;
2987 		pr_reg->pr_reg_nacl = NULL;
2988 		kfree(pr_reg->pr_aptpl_buf);
2989 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2990 	}
2991 }
2992 
2993 static int core_scsi3_pro_preempt(
2994 	struct se_cmd *cmd,
2995 	int type,
2996 	int scope,
2997 	u64 res_key,
2998 	u64 sa_res_key,
2999 	int abort)
3000 {
3001 	struct se_device *dev = cmd->se_dev;
3002 	struct se_node_acl *pr_reg_nacl;
3003 	struct se_session *se_sess = cmd->se_sess;
3004 	LIST_HEAD(preempt_and_abort_list);
3005 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
3006 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3007 	u32 pr_res_mapped_lun = 0;
3008 	int all_reg = 0, calling_it_nexus = 0, released_regs = 0;
3009 	int prh_type = 0, prh_scope = 0, ret;
3010 
3011 	if (!se_sess) {
3012 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3013 		return -EINVAL;
3014 	}
3015 
3016 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3017 				se_sess);
3018 	if (!pr_reg_n) {
3019 		pr_err("SPC-3 PR: Unable to locate"
3020 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
3021 			(abort) ? "_AND_ABORT" : "");
3022 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3023 		return -EINVAL;
3024 	}
3025 	if (pr_reg_n->pr_res_key != res_key) {
3026 		core_scsi3_put_pr_reg(pr_reg_n);
3027 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3028 		return -EINVAL;
3029 	}
3030 	if (scope != PR_SCOPE_LU_SCOPE) {
3031 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
3032 		core_scsi3_put_pr_reg(pr_reg_n);
3033 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3034 		return -EINVAL;
3035 	}
3036 
3037 	spin_lock(&dev->dev_reservation_lock);
3038 	pr_res_holder = dev->dev_pr_res_holder;
3039 	if (pr_res_holder &&
3040 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3041 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
3042 		all_reg = 1;
3043 
3044 	if (!all_reg && !sa_res_key) {
3045 		spin_unlock(&dev->dev_reservation_lock);
3046 		core_scsi3_put_pr_reg(pr_reg_n);
3047 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3048 		return -EINVAL;
3049 	}
3050 	/*
3051 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
3052 	 *
3053 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
3054 	 * persistent reservation holder or there is no persistent reservation
3055 	 * holder (i.e., there is no persistent reservation), then the device
3056 	 * server shall perform a preempt by doing the following in an
3057 	 * uninterrupted series of actions. (See below..)
3058 	 */
3059 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
3060 		/*
3061 		 * No existing or SA Reservation Key matching reservations..
3062 		 *
3063 		 * PROUT SA PREEMPT with All Registrant type reservations are
3064 		 * allowed to be processed without a matching SA Reservation Key
3065 		 */
3066 		spin_lock(&pr_tmpl->registration_lock);
3067 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3068 				&pr_tmpl->registration_list, pr_reg_list) {
3069 			/*
3070 			 * Removing of registrations in non all registrants
3071 			 * type reservations without a matching SA reservation
3072 			 * key.
3073 			 *
3074 			 * a) Remove the registrations for all I_T nexuses
3075 			 *    specified by the SERVICE ACTION RESERVATION KEY
3076 			 *    field;
3077 			 * b) Ignore the contents of the SCOPE and TYPE fields;
3078 			 * c) Process tasks as defined in 5.7.1; and
3079 			 * d) Establish a unit attention condition for the
3080 			 *    initiator port associated with every I_T nexus
3081 			 *    that lost its registration other than the I_T
3082 			 *    nexus on which the PERSISTENT RESERVE OUT command
3083 			 *    was received, with the additional sense code set
3084 			 *    to REGISTRATIONS PREEMPTED.
3085 			 */
3086 			if (!all_reg) {
3087 				if (pr_reg->pr_res_key != sa_res_key)
3088 					continue;
3089 
3090 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3091 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3092 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3093 				__core_scsi3_free_registration(dev, pr_reg,
3094 					(abort) ? &preempt_and_abort_list :
3095 						NULL, calling_it_nexus);
3096 				released_regs++;
3097 			} else {
3098 				/*
3099 				 * Case for any existing all registrants type
3100 				 * reservation, follow logic in spc4r17 section
3101 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
3102 				 *
3103 				 * For a ZERO SA Reservation key, release
3104 				 * all other registrations and do an implict
3105 				 * release of active persistent reservation.
3106 				 *
3107 				 * For a non-ZERO SA Reservation key, only
3108 				 * release the matching reservation key from
3109 				 * registrations.
3110 				 */
3111 				if ((sa_res_key) &&
3112 				     (pr_reg->pr_res_key != sa_res_key))
3113 					continue;
3114 
3115 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3116 				if (calling_it_nexus)
3117 					continue;
3118 
3119 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3120 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3121 				__core_scsi3_free_registration(dev, pr_reg,
3122 					(abort) ? &preempt_and_abort_list :
3123 						NULL, 0);
3124 				released_regs++;
3125 			}
3126 			if (!calling_it_nexus)
3127 				core_scsi3_ua_allocate(pr_reg_nacl,
3128 					pr_res_mapped_lun, 0x2A,
3129 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3130 		}
3131 		spin_unlock(&pr_tmpl->registration_lock);
3132 		/*
3133 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
3134 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
3135 		 * RESERVATION KEY field to a value that does not match any
3136 		 * registered reservation key, then the device server shall
3137 		 * complete the command with RESERVATION CONFLICT status.
3138 		 */
3139 		if (!released_regs) {
3140 			spin_unlock(&dev->dev_reservation_lock);
3141 			core_scsi3_put_pr_reg(pr_reg_n);
3142 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3143 			return -EINVAL;
3144 		}
3145 		/*
3146 		 * For an existing all registrants type reservation
3147 		 * with a zero SA rservation key, preempt the existing
3148 		 * reservation with the new PR type and scope.
3149 		 */
3150 		if (pr_res_holder && all_reg && !(sa_res_key)) {
3151 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3152 				(abort) ? &preempt_and_abort_list : NULL,
3153 				type, scope, abort);
3154 
3155 			if (abort)
3156 				core_scsi3_release_preempt_and_abort(
3157 					&preempt_and_abort_list, pr_reg_n);
3158 		}
3159 		spin_unlock(&dev->dev_reservation_lock);
3160 
3161 		if (pr_tmpl->pr_aptpl_active) {
3162 			ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3163 					&pr_reg_n->pr_aptpl_buf[0],
3164 					pr_tmpl->pr_aptpl_buf_len);
3165 			if (!ret)
3166 				pr_debug("SPC-3 PR: Updated APTPL"
3167 					" metadata for  PREEMPT%s\n", (abort) ?
3168 					"_AND_ABORT" : "");
3169 		}
3170 
3171 		core_scsi3_put_pr_reg(pr_reg_n);
3172 		core_scsi3_pr_generation(cmd->se_dev);
3173 		return 0;
3174 	}
3175 	/*
3176 	 * The PREEMPTing SA reservation key matches that of the
3177 	 * existing persistent reservation, first, we check if
3178 	 * we are preempting our own reservation.
3179 	 * From spc4r17, section 5.7.11.4.3 Preempting
3180 	 * persistent reservations and registration handling
3181 	 *
3182 	 * If an all registrants persistent reservation is not
3183 	 * present, it is not an error for the persistent
3184 	 * reservation holder to preempt itself (i.e., a
3185 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3186 	 * or a PREEMPT AND ABORT service action with the
3187 	 * SERVICE ACTION RESERVATION KEY value equal to the
3188 	 * persistent reservation holder's reservation key that
3189 	 * is received from the persistent reservation holder).
3190 	 * In that case, the device server shall establish the
3191 	 * new persistent reservation and maintain the
3192 	 * registration.
3193 	 */
3194 	prh_type = pr_res_holder->pr_res_type;
3195 	prh_scope = pr_res_holder->pr_res_scope;
3196 	/*
3197 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3198 	 * persistent reservation holder (see 5.7.10), the device
3199 	 * server shall perform a preempt by doing the following as
3200 	 * an uninterrupted series of actions:
3201 	 *
3202 	 * a) Release the persistent reservation for the holder
3203 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3204 	 */
3205 	if (pr_reg_n != pr_res_holder)
3206 		__core_scsi3_complete_pro_release(dev,
3207 				pr_res_holder->pr_reg_nacl,
3208 				dev->dev_pr_res_holder, 0);
3209 	/*
3210 	 * b) Remove the registrations for all I_T nexuses identified
3211 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3212 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3213 	 *    OUT command. If an all registrants persistent reservation
3214 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3215 	 *    is set to zero, then all registrations shall be removed
3216 	 *    except for that of the I_T nexus that is being used for
3217 	 *    the PERSISTENT RESERVE OUT command;
3218 	 */
3219 	spin_lock(&pr_tmpl->registration_lock);
3220 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3221 			&pr_tmpl->registration_list, pr_reg_list) {
3222 
3223 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3224 		if (calling_it_nexus)
3225 			continue;
3226 
3227 		if (pr_reg->pr_res_key != sa_res_key)
3228 			continue;
3229 
3230 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3231 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3232 		__core_scsi3_free_registration(dev, pr_reg,
3233 				(abort) ? &preempt_and_abort_list : NULL,
3234 				calling_it_nexus);
3235 		/*
3236 		 * e) Establish a unit attention condition for the initiator
3237 		 *    port associated with every I_T nexus that lost its
3238 		 *    persistent reservation and/or registration, with the
3239 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3240 		 */
3241 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3242 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3243 	}
3244 	spin_unlock(&pr_tmpl->registration_lock);
3245 	/*
3246 	 * c) Establish a persistent reservation for the preempting
3247 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3248 	 */
3249 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3250 			(abort) ? &preempt_and_abort_list : NULL,
3251 			type, scope, abort);
3252 	/*
3253 	 * d) Process tasks as defined in 5.7.1;
3254 	 * e) See above..
3255 	 * f) If the type or scope has changed, then for every I_T nexus
3256 	 *    whose reservation key was not removed, except for the I_T
3257 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3258 	 *    received, the device server shall establish a unit
3259 	 *    attention condition for the initiator port associated with
3260 	 *    that I_T nexus, with the additional sense code set to
3261 	 *    RESERVATIONS RELEASED. If the type or scope have not
3262 	 *    changed, then no unit attention condition(s) shall be
3263 	 *    established for this reason.
3264 	 */
3265 	if ((prh_type != type) || (prh_scope != scope)) {
3266 		spin_lock(&pr_tmpl->registration_lock);
3267 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3268 				&pr_tmpl->registration_list, pr_reg_list) {
3269 
3270 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3271 			if (calling_it_nexus)
3272 				continue;
3273 
3274 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
3275 					pr_reg->pr_res_mapped_lun, 0x2A,
3276 					ASCQ_2AH_RESERVATIONS_RELEASED);
3277 		}
3278 		spin_unlock(&pr_tmpl->registration_lock);
3279 	}
3280 	spin_unlock(&dev->dev_reservation_lock);
3281 	/*
3282 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3283 	 * All received CDBs for the matching existing reservation and
3284 	 * registrations undergo ABORT_TASK logic.
3285 	 *
3286 	 * From there, core_scsi3_release_preempt_and_abort() will
3287 	 * release every registration in the list (which have already
3288 	 * been removed from the primary pr_reg list), except the
3289 	 * new persistent reservation holder, the calling Initiator Port.
3290 	 */
3291 	if (abort) {
3292 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3293 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3294 						pr_reg_n);
3295 	}
3296 
3297 	if (pr_tmpl->pr_aptpl_active) {
3298 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3299 				&pr_reg_n->pr_aptpl_buf[0],
3300 				pr_tmpl->pr_aptpl_buf_len);
3301 		if (!ret)
3302 			pr_debug("SPC-3 PR: Updated APTPL metadata for PREEMPT"
3303 				"%s\n", (abort) ? "_AND_ABORT" : "");
3304 	}
3305 
3306 	core_scsi3_put_pr_reg(pr_reg_n);
3307 	core_scsi3_pr_generation(cmd->se_dev);
3308 	return 0;
3309 }
3310 
3311 static int core_scsi3_emulate_pro_preempt(
3312 	struct se_cmd *cmd,
3313 	int type,
3314 	int scope,
3315 	u64 res_key,
3316 	u64 sa_res_key,
3317 	int abort)
3318 {
3319 	int ret = 0;
3320 
3321 	switch (type) {
3322 	case PR_TYPE_WRITE_EXCLUSIVE:
3323 	case PR_TYPE_EXCLUSIVE_ACCESS:
3324 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3325 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3326 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3327 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3328 		ret = core_scsi3_pro_preempt(cmd, type, scope,
3329 				res_key, sa_res_key, abort);
3330 		break;
3331 	default:
3332 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3333 			" Type: 0x%02x\n", (abort) ? "_AND_ABORT" : "", type);
3334 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3335 		return -EINVAL;
3336 	}
3337 
3338 	return ret;
3339 }
3340 
3341 
3342 static int core_scsi3_emulate_pro_register_and_move(
3343 	struct se_cmd *cmd,
3344 	u64 res_key,
3345 	u64 sa_res_key,
3346 	int aptpl,
3347 	int unreg)
3348 {
3349 	struct se_session *se_sess = cmd->se_sess;
3350 	struct se_device *dev = cmd->se_dev;
3351 	struct se_dev_entry *dest_se_deve = NULL;
3352 	struct se_lun *se_lun = cmd->se_lun;
3353 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3354 	struct se_port *se_port;
3355 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3356 	struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3357 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3358 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3359 	unsigned char *buf;
3360 	unsigned char *initiator_str;
3361 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
3362 	u32 tid_len, tmp_tid_len;
3363 	int new_reg = 0, type, scope, ret, matching_iname, prf_isid;
3364 	unsigned short rtpi;
3365 	unsigned char proto_ident;
3366 
3367 	if (!se_sess || !se_lun) {
3368 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3369 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3370 		return -EINVAL;
3371 	}
3372 	memset(dest_iport, 0, 64);
3373 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3374 	se_tpg = se_sess->se_tpg;
3375 	tf_ops = se_tpg->se_tpg_tfo;
3376 	/*
3377 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3378 	 *	Register behaviors for a REGISTER AND MOVE service action
3379 	 *
3380 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3381 	 */
3382 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3383 				se_sess);
3384 	if (!pr_reg) {
3385 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3386 			" *pr_reg for REGISTER_AND_MOVE\n");
3387 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3388 		return -EINVAL;
3389 	}
3390 	/*
3391 	 * The provided reservation key much match the existing reservation key
3392 	 * provided during this initiator's I_T nexus registration.
3393 	 */
3394 	if (res_key != pr_reg->pr_res_key) {
3395 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3396 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3397 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3398 		core_scsi3_put_pr_reg(pr_reg);
3399 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3400 		return -EINVAL;
3401 	}
3402 	/*
3403 	 * The service active reservation key needs to be non zero
3404 	 */
3405 	if (!sa_res_key) {
3406 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3407 			" sa_res_key\n");
3408 		core_scsi3_put_pr_reg(pr_reg);
3409 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3410 		return -EINVAL;
3411 	}
3412 
3413 	/*
3414 	 * Determine the Relative Target Port Identifier where the reservation
3415 	 * will be moved to for the TransportID containing SCSI initiator WWN
3416 	 * information.
3417 	 */
3418 	buf = transport_kmap_data_sg(cmd);
3419 	rtpi = (buf[18] & 0xff) << 8;
3420 	rtpi |= buf[19] & 0xff;
3421 	tid_len = (buf[20] & 0xff) << 24;
3422 	tid_len |= (buf[21] & 0xff) << 16;
3423 	tid_len |= (buf[22] & 0xff) << 8;
3424 	tid_len |= buf[23] & 0xff;
3425 	transport_kunmap_data_sg(cmd);
3426 	buf = NULL;
3427 
3428 	if ((tid_len + 24) != cmd->data_length) {
3429 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3430 			" does not equal CDB data_length: %u\n", tid_len,
3431 			cmd->data_length);
3432 		core_scsi3_put_pr_reg(pr_reg);
3433 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3434 		return -EINVAL;
3435 	}
3436 
3437 	spin_lock(&dev->se_port_lock);
3438 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3439 		if (se_port->sep_rtpi != rtpi)
3440 			continue;
3441 		dest_se_tpg = se_port->sep_tpg;
3442 		if (!dest_se_tpg)
3443 			continue;
3444 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3445 		if (!dest_tf_ops)
3446 			continue;
3447 
3448 		atomic_inc(&dest_se_tpg->tpg_pr_ref_count);
3449 		smp_mb__after_atomic_inc();
3450 		spin_unlock(&dev->se_port_lock);
3451 
3452 		ret = core_scsi3_tpg_depend_item(dest_se_tpg);
3453 		if (ret != 0) {
3454 			pr_err("core_scsi3_tpg_depend_item() failed"
3455 				" for dest_se_tpg\n");
3456 			atomic_dec(&dest_se_tpg->tpg_pr_ref_count);
3457 			smp_mb__after_atomic_dec();
3458 			core_scsi3_put_pr_reg(pr_reg);
3459 			cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3460 			return -EINVAL;
3461 		}
3462 
3463 		spin_lock(&dev->se_port_lock);
3464 		break;
3465 	}
3466 	spin_unlock(&dev->se_port_lock);
3467 
3468 	if (!dest_se_tpg || !dest_tf_ops) {
3469 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3470 			" fabric ops from Relative Target Port Identifier:"
3471 			" %hu\n", rtpi);
3472 		core_scsi3_put_pr_reg(pr_reg);
3473 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3474 		return -EINVAL;
3475 	}
3476 
3477 	buf = transport_kmap_data_sg(cmd);
3478 	proto_ident = (buf[24] & 0x0f);
3479 #if 0
3480 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3481 			" 0x%02x\n", proto_ident);
3482 #endif
3483 	if (proto_ident != dest_tf_ops->get_fabric_proto_ident(dest_se_tpg)) {
3484 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3485 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3486 			" from fabric: %s\n", proto_ident,
3487 			dest_tf_ops->get_fabric_proto_ident(dest_se_tpg),
3488 			dest_tf_ops->get_fabric_name());
3489 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3490 		ret = -EINVAL;
3491 		goto out;
3492 	}
3493 	if (dest_tf_ops->tpg_parse_pr_out_transport_id == NULL) {
3494 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Fabric does not"
3495 			" containg a valid tpg_parse_pr_out_transport_id"
3496 			" function pointer\n");
3497 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3498 		ret = -EINVAL;
3499 		goto out;
3500 	}
3501 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(dest_se_tpg,
3502 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3503 	if (!initiator_str) {
3504 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3505 			" initiator_str from Transport ID\n");
3506 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3507 		ret = -EINVAL;
3508 		goto out;
3509 	}
3510 
3511 	transport_kunmap_data_sg(cmd);
3512 	buf = NULL;
3513 
3514 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3515 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3516 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3517 		iport_ptr : "");
3518 	/*
3519 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3520 	 * action specifies a TransportID that is the same as the initiator port
3521 	 * of the I_T nexus for the command received, then the command shall
3522 	 * be terminated with CHECK CONDITION status, with the sense key set to
3523 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3524 	 * IN PARAMETER LIST.
3525 	 */
3526 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3527 	matching_iname = (!strcmp(initiator_str,
3528 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3529 	if (!matching_iname)
3530 		goto after_iport_check;
3531 
3532 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3533 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3534 			" matches: %s on received I_T Nexus\n", initiator_str,
3535 			pr_reg_nacl->initiatorname);
3536 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3537 		ret = -EINVAL;
3538 		goto out;
3539 	}
3540 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3541 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3542 			" matches: %s %s on received I_T Nexus\n",
3543 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3544 			pr_reg->pr_reg_isid);
3545 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3546 		ret = -EINVAL;
3547 		goto out;
3548 	}
3549 after_iport_check:
3550 	/*
3551 	 * Locate the destination struct se_node_acl from the received Transport ID
3552 	 */
3553 	spin_lock_irq(&dest_se_tpg->acl_node_lock);
3554 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3555 				initiator_str);
3556 	if (dest_node_acl) {
3557 		atomic_inc(&dest_node_acl->acl_pr_ref_count);
3558 		smp_mb__after_atomic_inc();
3559 	}
3560 	spin_unlock_irq(&dest_se_tpg->acl_node_lock);
3561 
3562 	if (!dest_node_acl) {
3563 		pr_err("Unable to locate %s dest_node_acl for"
3564 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3565 			initiator_str);
3566 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3567 		ret = -EINVAL;
3568 		goto out;
3569 	}
3570 	ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
3571 	if (ret != 0) {
3572 		pr_err("core_scsi3_nodeacl_depend_item() for"
3573 			" dest_node_acl\n");
3574 		atomic_dec(&dest_node_acl->acl_pr_ref_count);
3575 		smp_mb__after_atomic_dec();
3576 		dest_node_acl = NULL;
3577 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3578 		ret = -EINVAL;
3579 		goto out;
3580 	}
3581 #if 0
3582 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3583 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3584 		dest_node_acl->initiatorname);
3585 #endif
3586 	/*
3587 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3588 	 * PORT IDENTIFIER.
3589 	 */
3590 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3591 	if (!dest_se_deve) {
3592 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3593 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3594 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3595 		ret = -EINVAL;
3596 		goto out;
3597 	}
3598 
3599 	ret = core_scsi3_lunacl_depend_item(dest_se_deve);
3600 	if (ret < 0) {
3601 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3602 		atomic_dec(&dest_se_deve->pr_ref_count);
3603 		smp_mb__after_atomic_dec();
3604 		dest_se_deve = NULL;
3605 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3606 		ret = -EINVAL;
3607 		goto out;
3608 	}
3609 #if 0
3610 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3611 		" ACL for dest_se_deve->mapped_lun: %u\n",
3612 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3613 		dest_se_deve->mapped_lun);
3614 #endif
3615 	/*
3616 	 * A persistent reservation needs to already existing in order to
3617 	 * successfully complete the REGISTER_AND_MOVE service action..
3618 	 */
3619 	spin_lock(&dev->dev_reservation_lock);
3620 	pr_res_holder = dev->dev_pr_res_holder;
3621 	if (!pr_res_holder) {
3622 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3623 			" currently held\n");
3624 		spin_unlock(&dev->dev_reservation_lock);
3625 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3626 		ret = -EINVAL;
3627 		goto out;
3628 	}
3629 	/*
3630 	 * The received on I_T Nexus must be the reservation holder.
3631 	 *
3632 	 * From spc4r17 section 5.7.8  Table 50 --
3633 	 * 	Register behaviors for a REGISTER AND MOVE service action
3634 	 */
3635 	if (pr_res_holder != pr_reg) {
3636 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3637 			" Nexus is not reservation holder\n");
3638 		spin_unlock(&dev->dev_reservation_lock);
3639 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3640 		ret = -EINVAL;
3641 		goto out;
3642 	}
3643 	/*
3644 	 * From spc4r17 section 5.7.8: registering and moving reservation
3645 	 *
3646 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3647 	 * action is received and the established persistent reservation is a
3648 	 * Write Exclusive - All Registrants type or Exclusive Access -
3649 	 * All Registrants type reservation, then the command shall be completed
3650 	 * with RESERVATION CONFLICT status.
3651 	 */
3652 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3653 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3654 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3655 			" reservation for type: %s\n",
3656 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3657 		spin_unlock(&dev->dev_reservation_lock);
3658 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3659 		ret = -EINVAL;
3660 		goto out;
3661 	}
3662 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3663 	/*
3664 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3665 	 */
3666 	type = pr_res_holder->pr_res_type;
3667 	scope = pr_res_holder->pr_res_type;
3668 	/*
3669 	 * c) Associate the reservation key specified in the SERVICE ACTION
3670 	 *    RESERVATION KEY field with the I_T nexus specified as the
3671 	 *    destination of the register and move, where:
3672 	 *    A) The I_T nexus is specified by the TransportID and the
3673 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3674 	 *    B) Regardless of the TransportID format used, the association for
3675 	 *       the initiator port is based on either the initiator port name
3676 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3677 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3678 	 *       transport protocols where port names are not required;
3679 	 * d) Register the reservation key specified in the SERVICE ACTION
3680 	 *    RESERVATION KEY field;
3681 	 * e) Retain the reservation key specified in the SERVICE ACTION
3682 	 *    RESERVATION KEY field and associated information;
3683 	 *
3684 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3685 	 * register an I_T nexus that is already registered with the same
3686 	 * reservation key or a different reservation key.
3687 	 */
3688 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3689 					iport_ptr);
3690 	if (!dest_pr_reg) {
3691 		ret = core_scsi3_alloc_registration(cmd->se_dev,
3692 				dest_node_acl, dest_se_deve, iport_ptr,
3693 				sa_res_key, 0, aptpl, 2, 1);
3694 		if (ret != 0) {
3695 			spin_unlock(&dev->dev_reservation_lock);
3696 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3697 			ret = -EINVAL;
3698 			goto out;
3699 		}
3700 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3701 						iport_ptr);
3702 		new_reg = 1;
3703 	}
3704 	/*
3705 	 * f) Release the persistent reservation for the persistent reservation
3706 	 *    holder (i.e., the I_T nexus on which the
3707 	 */
3708 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3709 			dev->dev_pr_res_holder, 0);
3710 	/*
3711 	 * g) Move the persistent reservation to the specified I_T nexus using
3712 	 *    the same scope and type as the persistent reservation released in
3713 	 *    item f); and
3714 	 */
3715 	dev->dev_pr_res_holder = dest_pr_reg;
3716 	dest_pr_reg->pr_res_holder = 1;
3717 	dest_pr_reg->pr_res_type = type;
3718 	pr_reg->pr_res_scope = scope;
3719 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
3720 				PR_REG_ISID_ID_LEN);
3721 	/*
3722 	 * Increment PRGeneration for existing registrations..
3723 	 */
3724 	if (!new_reg)
3725 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3726 	spin_unlock(&dev->dev_reservation_lock);
3727 
3728 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3729 		" created new reservation holder TYPE: %s on object RTPI:"
3730 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3731 		core_scsi3_pr_dump_type(type), rtpi,
3732 		dest_pr_reg->pr_res_generation);
3733 	pr_debug("SPC-3 PR Successfully moved reservation from"
3734 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3735 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3736 		(prf_isid) ? &i_buf[0] : "", dest_tf_ops->get_fabric_name(),
3737 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3738 		iport_ptr : "");
3739 	/*
3740 	 * It is now safe to release configfs group dependencies for destination
3741 	 * of Transport ID Initiator Device/Port Identifier
3742 	 */
3743 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3744 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3745 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3746 	/*
3747 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3748 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3749 	 */
3750 	if (unreg) {
3751 		spin_lock(&pr_tmpl->registration_lock);
3752 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3753 		spin_unlock(&pr_tmpl->registration_lock);
3754 	} else
3755 		core_scsi3_put_pr_reg(pr_reg);
3756 
3757 	/*
3758 	 * Clear the APTPL metadata if APTPL has been disabled, otherwise
3759 	 * write out the updated metadata to struct file for this SCSI device.
3760 	 */
3761 	if (!aptpl) {
3762 		pr_tmpl->pr_aptpl_active = 0;
3763 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
3764 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
3765 				" REGISTER_AND_MOVE\n");
3766 	} else {
3767 		pr_tmpl->pr_aptpl_active = 1;
3768 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3769 				&dest_pr_reg->pr_aptpl_buf[0],
3770 				pr_tmpl->pr_aptpl_buf_len);
3771 		if (!ret)
3772 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for"
3773 					" REGISTER_AND_MOVE\n");
3774 	}
3775 
3776 	transport_kunmap_data_sg(cmd);
3777 
3778 	core_scsi3_put_pr_reg(dest_pr_reg);
3779 	return 0;
3780 out:
3781 	if (buf)
3782 		transport_kunmap_data_sg(cmd);
3783 	if (dest_se_deve)
3784 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3785 	if (dest_node_acl)
3786 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3787 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3788 	core_scsi3_put_pr_reg(pr_reg);
3789 	return ret;
3790 }
3791 
3792 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3793 {
3794 	unsigned int __v1, __v2;
3795 
3796 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3797 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3798 
3799 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3800 }
3801 
3802 /*
3803  * See spc4r17 section 6.14 Table 170
3804  */
3805 int target_scsi3_emulate_pr_out(struct se_task *task)
3806 {
3807 	struct se_cmd *cmd = task->task_se_cmd;
3808 	unsigned char *cdb = &cmd->t_task_cdb[0];
3809 	unsigned char *buf;
3810 	u64 res_key, sa_res_key;
3811 	int sa, scope, type, aptpl;
3812 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3813 	int ret;
3814 
3815 	/*
3816 	 * Following spc2r20 5.5.1 Reservations overview:
3817 	 *
3818 	 * If a logical unit has been reserved by any RESERVE command and is
3819 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3820 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3821 	 * initiator or service action and shall terminate with a RESERVATION
3822 	 * CONFLICT status.
3823 	 */
3824 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS) {
3825 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3826 			" SPC-2 reservation is held, returning"
3827 			" RESERVATION_CONFLICT\n");
3828 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3829 		ret = EINVAL;
3830 		goto out;
3831 	}
3832 
3833 	/*
3834 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3835 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3836 	 */
3837 	if (!cmd->se_sess) {
3838 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3839 		return -EINVAL;
3840 	}
3841 
3842 	if (cmd->data_length < 24) {
3843 		pr_warn("SPC-PR: Received PR OUT parameter list"
3844 			" length too small: %u\n", cmd->data_length);
3845 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3846 		ret = -EINVAL;
3847 		goto out;
3848 	}
3849 	/*
3850 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3851 	 */
3852 	sa = (cdb[1] & 0x1f);
3853 	scope = (cdb[2] & 0xf0);
3854 	type = (cdb[2] & 0x0f);
3855 
3856 	buf = transport_kmap_data_sg(cmd);
3857 	/*
3858 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3859 	 */
3860 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3861 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3862 	/*
3863 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3864 	 * SCSI TransportIDs.
3865 	 */
3866 	if (sa != PRO_REGISTER_AND_MOVE) {
3867 		spec_i_pt = (buf[20] & 0x08);
3868 		all_tg_pt = (buf[20] & 0x04);
3869 		aptpl = (buf[20] & 0x01);
3870 	} else {
3871 		aptpl = (buf[17] & 0x01);
3872 		unreg = (buf[17] & 0x02);
3873 	}
3874 	transport_kunmap_data_sg(cmd);
3875 	buf = NULL;
3876 
3877 	/*
3878 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3879 	 */
3880 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER)) {
3881 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3882 		ret = -EINVAL;
3883 		goto out;
3884 	}
3885 
3886 	/*
3887 	 * From spc4r17 section 6.14:
3888 	 *
3889 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3890 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3891 	 * the command shall be terminated with CHECK CONDITION status, with
3892 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3893 	 * code set to PARAMETER LIST LENGTH ERROR.
3894 	 */
3895 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3896 	    (cmd->data_length != 24)) {
3897 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3898 			" list length: %u\n", cmd->data_length);
3899 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3900 		ret = -EINVAL;
3901 		goto out;
3902 	}
3903 	/*
3904 	 * (core_scsi3_emulate_pro_* function parameters
3905 	 * are defined by spc4r17 Table 174:
3906 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3907 	 */
3908 	switch (sa) {
3909 	case PRO_REGISTER:
3910 		ret = core_scsi3_emulate_pro_register(cmd,
3911 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 0);
3912 		break;
3913 	case PRO_RESERVE:
3914 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3915 		break;
3916 	case PRO_RELEASE:
3917 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3918 		break;
3919 	case PRO_CLEAR:
3920 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3921 		break;
3922 	case PRO_PREEMPT:
3923 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3924 					res_key, sa_res_key, 0);
3925 		break;
3926 	case PRO_PREEMPT_AND_ABORT:
3927 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3928 					res_key, sa_res_key, 1);
3929 		break;
3930 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3931 		ret = core_scsi3_emulate_pro_register(cmd,
3932 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 1);
3933 		break;
3934 	case PRO_REGISTER_AND_MOVE:
3935 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3936 				sa_res_key, aptpl, unreg);
3937 		break;
3938 	default:
3939 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3940 			" action: 0x%02x\n", cdb[1] & 0x1f);
3941 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3942 		ret = -EINVAL;
3943 		break;
3944 	}
3945 
3946 out:
3947 	if (!ret) {
3948 		task->task_scsi_status = GOOD;
3949 		transport_complete_task(task, 1);
3950 	}
3951 	return ret;
3952 }
3953 
3954 /*
3955  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3956  *
3957  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3958  */
3959 static int core_scsi3_pri_read_keys(struct se_cmd *cmd)
3960 {
3961 	struct se_device *se_dev = cmd->se_dev;
3962 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
3963 	struct t10_pr_registration *pr_reg;
3964 	unsigned char *buf;
3965 	u32 add_len = 0, off = 8;
3966 
3967 	if (cmd->data_length < 8) {
3968 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3969 			" too small\n", cmd->data_length);
3970 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3971 		return -EINVAL;
3972 	}
3973 
3974 	buf = transport_kmap_data_sg(cmd);
3975 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
3976 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
3977 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
3978 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
3979 
3980 	spin_lock(&su_dev->t10_pr.registration_lock);
3981 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
3982 			pr_reg_list) {
3983 		/*
3984 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3985 		 * next reservation key list descriptor.
3986 		 */
3987 		if ((add_len + 8) > (cmd->data_length - 8))
3988 			break;
3989 
3990 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3991 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3992 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3993 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3994 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3995 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3996 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3997 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3998 
3999 		add_len += 8;
4000 	}
4001 	spin_unlock(&su_dev->t10_pr.registration_lock);
4002 
4003 	buf[4] = ((add_len >> 24) & 0xff);
4004 	buf[5] = ((add_len >> 16) & 0xff);
4005 	buf[6] = ((add_len >> 8) & 0xff);
4006 	buf[7] = (add_len & 0xff);
4007 
4008 	transport_kunmap_data_sg(cmd);
4009 
4010 	return 0;
4011 }
4012 
4013 /*
4014  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
4015  *
4016  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
4017  */
4018 static int core_scsi3_pri_read_reservation(struct se_cmd *cmd)
4019 {
4020 	struct se_device *se_dev = cmd->se_dev;
4021 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
4022 	struct t10_pr_registration *pr_reg;
4023 	unsigned char *buf;
4024 	u64 pr_res_key;
4025 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
4026 
4027 	if (cmd->data_length < 8) {
4028 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
4029 			" too small\n", cmd->data_length);
4030 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4031 		return -EINVAL;
4032 	}
4033 
4034 	buf = transport_kmap_data_sg(cmd);
4035 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
4036 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
4037 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
4038 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
4039 
4040 	spin_lock(&se_dev->dev_reservation_lock);
4041 	pr_reg = se_dev->dev_pr_res_holder;
4042 	if ((pr_reg)) {
4043 		/*
4044 		 * Set the hardcoded Additional Length
4045 		 */
4046 		buf[4] = ((add_len >> 24) & 0xff);
4047 		buf[5] = ((add_len >> 16) & 0xff);
4048 		buf[6] = ((add_len >> 8) & 0xff);
4049 		buf[7] = (add_len & 0xff);
4050 
4051 		if (cmd->data_length < 22)
4052 			goto err;
4053 
4054 		/*
4055 		 * Set the Reservation key.
4056 		 *
4057 		 * From spc4r17, section 5.7.10:
4058 		 * A persistent reservation holder has its reservation key
4059 		 * returned in the parameter data from a PERSISTENT
4060 		 * RESERVE IN command with READ RESERVATION service action as
4061 		 * follows:
4062 		 * a) For a persistent reservation of the type Write Exclusive
4063 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
4064 		 *      the reservation key shall be set to zero; or
4065 		 * b) For all other persistent reservation types, the
4066 		 *    reservation key shall be set to the registered
4067 		 *    reservation key for the I_T nexus that holds the
4068 		 *    persistent reservation.
4069 		 */
4070 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
4071 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
4072 			pr_res_key = 0;
4073 		else
4074 			pr_res_key = pr_reg->pr_res_key;
4075 
4076 		buf[8] = ((pr_res_key >> 56) & 0xff);
4077 		buf[9] = ((pr_res_key >> 48) & 0xff);
4078 		buf[10] = ((pr_res_key >> 40) & 0xff);
4079 		buf[11] = ((pr_res_key >> 32) & 0xff);
4080 		buf[12] = ((pr_res_key >> 24) & 0xff);
4081 		buf[13] = ((pr_res_key >> 16) & 0xff);
4082 		buf[14] = ((pr_res_key >> 8) & 0xff);
4083 		buf[15] = (pr_res_key & 0xff);
4084 		/*
4085 		 * Set the SCOPE and TYPE
4086 		 */
4087 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
4088 			  (pr_reg->pr_res_type & 0x0f);
4089 	}
4090 
4091 err:
4092 	spin_unlock(&se_dev->dev_reservation_lock);
4093 	transport_kunmap_data_sg(cmd);
4094 
4095 	return 0;
4096 }
4097 
4098 /*
4099  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
4100  *
4101  * See spc4r17 section 6.13.4 Table 165
4102  */
4103 static int core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
4104 {
4105 	struct se_device *dev = cmd->se_dev;
4106 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
4107 	unsigned char *buf;
4108 	u16 add_len = 8; /* Hardcoded to 8. */
4109 
4110 	if (cmd->data_length < 6) {
4111 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
4112 			" %u too small\n", cmd->data_length);
4113 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4114 		return -EINVAL;
4115 	}
4116 
4117 	buf = transport_kmap_data_sg(cmd);
4118 
4119 	buf[0] = ((add_len << 8) & 0xff);
4120 	buf[1] = (add_len & 0xff);
4121 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
4122 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
4123 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
4124 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
4125 	/*
4126 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
4127 	 * set the TMV: Task Mask Valid bit.
4128 	 */
4129 	buf[3] |= 0x80;
4130 	/*
4131 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
4132 	 */
4133 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
4134 	/*
4135 	 * PTPL_A: Persistence across Target Power Loss Active bit
4136 	 */
4137 	if (pr_tmpl->pr_aptpl_active)
4138 		buf[3] |= 0x01;
4139 	/*
4140 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
4141 	 */
4142 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4143 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
4144 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
4145 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
4146 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
4147 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4148 
4149 	transport_kunmap_data_sg(cmd);
4150 
4151 	return 0;
4152 }
4153 
4154 /*
4155  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
4156  *
4157  * See spc4r17 section 6.13.5 Table 168 and 169
4158  */
4159 static int core_scsi3_pri_read_full_status(struct se_cmd *cmd)
4160 {
4161 	struct se_device *se_dev = cmd->se_dev;
4162 	struct se_node_acl *se_nacl;
4163 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
4164 	struct se_portal_group *se_tpg;
4165 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
4166 	struct t10_reservation *pr_tmpl = &se_dev->se_sub_dev->t10_pr;
4167 	unsigned char *buf;
4168 	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
4169 	u32 off = 8; /* off into first Full Status descriptor */
4170 	int format_code = 0;
4171 
4172 	if (cmd->data_length < 8) {
4173 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
4174 			" too small\n", cmd->data_length);
4175 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4176 		return -EINVAL;
4177 	}
4178 
4179 	buf = transport_kmap_data_sg(cmd);
4180 
4181 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
4182 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
4183 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
4184 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
4185 
4186 	spin_lock(&pr_tmpl->registration_lock);
4187 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
4188 			&pr_tmpl->registration_list, pr_reg_list) {
4189 
4190 		se_nacl = pr_reg->pr_reg_nacl;
4191 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
4192 		add_desc_len = 0;
4193 
4194 		atomic_inc(&pr_reg->pr_res_holders);
4195 		smp_mb__after_atomic_inc();
4196 		spin_unlock(&pr_tmpl->registration_lock);
4197 		/*
4198 		 * Determine expected length of $FABRIC_MOD specific
4199 		 * TransportID full status descriptor..
4200 		 */
4201 		exp_desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id_len(
4202 				se_tpg, se_nacl, pr_reg, &format_code);
4203 
4204 		if ((exp_desc_len + add_len) > cmd->data_length) {
4205 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
4206 				" out of buffer: %d\n", cmd->data_length);
4207 			spin_lock(&pr_tmpl->registration_lock);
4208 			atomic_dec(&pr_reg->pr_res_holders);
4209 			smp_mb__after_atomic_dec();
4210 			break;
4211 		}
4212 		/*
4213 		 * Set RESERVATION KEY
4214 		 */
4215 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
4216 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
4217 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
4218 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
4219 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
4220 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
4221 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
4222 		buf[off++] = (pr_reg->pr_res_key & 0xff);
4223 		off += 4; /* Skip Over Reserved area */
4224 
4225 		/*
4226 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
4227 		 */
4228 		if (pr_reg->pr_reg_all_tg_pt)
4229 			buf[off] = 0x02;
4230 		/*
4231 		 * The struct se_lun pointer will be present for the
4232 		 * reservation holder for PR_HOLDER bit.
4233 		 *
4234 		 * Also, if this registration is the reservation
4235 		 * holder, fill in SCOPE and TYPE in the next byte.
4236 		 */
4237 		if (pr_reg->pr_res_holder) {
4238 			buf[off++] |= 0x01;
4239 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
4240 				     (pr_reg->pr_res_type & 0x0f);
4241 		} else
4242 			off += 2;
4243 
4244 		off += 4; /* Skip over reserved area */
4245 		/*
4246 		 * From spc4r17 6.3.15:
4247 		 *
4248 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4249 		 * IDENTIFIER field contains the relative port identifier (see
4250 		 * 3.1.120) of the target port that is part of the I_T nexus
4251 		 * described by this full status descriptor. If the ALL_TG_PT
4252 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4253 		 * IDENTIFIER field are not defined by this standard.
4254 		 */
4255 		if (!pr_reg->pr_reg_all_tg_pt) {
4256 			struct se_port *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
4257 
4258 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
4259 			buf[off++] = (port->sep_rtpi & 0xff);
4260 		} else
4261 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFER */
4262 
4263 		/*
4264 		 * Now, have the $FABRIC_MOD fill in the protocol identifier
4265 		 */
4266 		desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id(se_tpg,
4267 				se_nacl, pr_reg, &format_code, &buf[off+4]);
4268 
4269 		spin_lock(&pr_tmpl->registration_lock);
4270 		atomic_dec(&pr_reg->pr_res_holders);
4271 		smp_mb__after_atomic_dec();
4272 		/*
4273 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4274 		 */
4275 		buf[off++] = ((desc_len >> 24) & 0xff);
4276 		buf[off++] = ((desc_len >> 16) & 0xff);
4277 		buf[off++] = ((desc_len >> 8) & 0xff);
4278 		buf[off++] = (desc_len & 0xff);
4279 		/*
4280 		 * Size of full desctipor header minus TransportID
4281 		 * containing $FABRIC_MOD specific) initiator device/port
4282 		 * WWN information.
4283 		 *
4284 		 *  See spc4r17 Section 6.13.5 Table 169
4285 		 */
4286 		add_desc_len = (24 + desc_len);
4287 
4288 		off += desc_len;
4289 		add_len += add_desc_len;
4290 	}
4291 	spin_unlock(&pr_tmpl->registration_lock);
4292 	/*
4293 	 * Set ADDITIONAL_LENGTH
4294 	 */
4295 	buf[4] = ((add_len >> 24) & 0xff);
4296 	buf[5] = ((add_len >> 16) & 0xff);
4297 	buf[6] = ((add_len >> 8) & 0xff);
4298 	buf[7] = (add_len & 0xff);
4299 
4300 	transport_kunmap_data_sg(cmd);
4301 
4302 	return 0;
4303 }
4304 
4305 int target_scsi3_emulate_pr_in(struct se_task *task)
4306 {
4307 	struct se_cmd *cmd = task->task_se_cmd;
4308 	int ret;
4309 
4310 	/*
4311 	 * Following spc2r20 5.5.1 Reservations overview:
4312 	 *
4313 	 * If a logical unit has been reserved by any RESERVE command and is
4314 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4315 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4316 	 * initiator or service action and shall terminate with a RESERVATION
4317 	 * CONFLICT status.
4318 	 */
4319 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS) {
4320 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4321 			" SPC-2 reservation is held, returning"
4322 			" RESERVATION_CONFLICT\n");
4323 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
4324 		return -EINVAL;
4325 	}
4326 
4327 	switch (cmd->t_task_cdb[1] & 0x1f) {
4328 	case PRI_READ_KEYS:
4329 		ret = core_scsi3_pri_read_keys(cmd);
4330 		break;
4331 	case PRI_READ_RESERVATION:
4332 		ret = core_scsi3_pri_read_reservation(cmd);
4333 		break;
4334 	case PRI_REPORT_CAPABILITIES:
4335 		ret = core_scsi3_pri_report_capabilities(cmd);
4336 		break;
4337 	case PRI_READ_FULL_STATUS:
4338 		ret = core_scsi3_pri_read_full_status(cmd);
4339 		break;
4340 	default:
4341 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4342 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4343 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4344 		ret = -EINVAL;
4345 		break;
4346 	}
4347 
4348 	if (!ret) {
4349 		task->task_scsi_status = GOOD;
4350 		transport_complete_task(task, 1);
4351 	}
4352 	return ret;
4353 }
4354 
4355 static int core_pt_reservation_check(struct se_cmd *cmd, u32 *pr_res_type)
4356 {
4357 	return 0;
4358 }
4359 
4360 static int core_pt_seq_non_holder(
4361 	struct se_cmd *cmd,
4362 	unsigned char *cdb,
4363 	u32 pr_reg_type)
4364 {
4365 	return 0;
4366 }
4367 
4368 int core_setup_reservations(struct se_device *dev, int force_pt)
4369 {
4370 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
4371 	struct t10_reservation *rest = &su_dev->t10_pr;
4372 	/*
4373 	 * If this device is from Target_Core_Mod/pSCSI, use the reservations
4374 	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
4375 	 * cause a problem because libata and some SATA RAID HBAs appear
4376 	 * under Linux/SCSI, but to emulate reservations themselves.
4377 	 */
4378 	if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
4379 	    !(dev->se_sub_dev->se_dev_attrib.emulate_reservations)) || force_pt) {
4380 		rest->res_type = SPC_PASSTHROUGH;
4381 		rest->pr_ops.t10_reservation_check = &core_pt_reservation_check;
4382 		rest->pr_ops.t10_seq_non_holder = &core_pt_seq_non_holder;
4383 		pr_debug("%s: Using SPC_PASSTHROUGH, no reservation"
4384 			" emulation\n", dev->transport->name);
4385 		return 0;
4386 	}
4387 	/*
4388 	 * If SPC-3 or above is reported by real or emulated struct se_device,
4389 	 * use emulated Persistent Reservations.
4390 	 */
4391 	if (dev->transport->get_device_rev(dev) >= SCSI_3) {
4392 		rest->res_type = SPC3_PERSISTENT_RESERVATIONS;
4393 		rest->pr_ops.t10_reservation_check = &core_scsi3_pr_reservation_check;
4394 		rest->pr_ops.t10_seq_non_holder = &core_scsi3_pr_seq_non_holder;
4395 		pr_debug("%s: Using SPC3_PERSISTENT_RESERVATIONS"
4396 			" emulation\n", dev->transport->name);
4397 	} else {
4398 		rest->res_type = SPC2_RESERVATIONS;
4399 		rest->pr_ops.t10_reservation_check = &core_scsi2_reservation_check;
4400 		rest->pr_ops.t10_seq_non_holder =
4401 				&core_scsi2_reservation_seq_non_holder;
4402 		pr_debug("%s: Using SPC2_RESERVATIONS emulation\n",
4403 			dev->transport->name);
4404 	}
4405 
4406 	return 0;
4407 }
4408