xref: /linux/drivers/target/target_core_pr.c (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
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_cmd *cmd)
197 {
198 	struct se_device *dev = cmd->se_dev;
199 	struct se_session *sess = cmd->se_sess;
200 	struct se_portal_group *tpg;
201 	int ret = 0, rc;
202 
203 	if (!sess || !sess->se_tpg)
204 		goto out;
205 	rc = target_check_scsi2_reservation_conflict(cmd);
206 	if (rc == 1)
207 		goto out;
208 	else if (rc < 0) {
209 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
210 		ret = -EINVAL;
211 		goto out;
212 	}
213 
214 	ret = 0;
215 	spin_lock(&dev->dev_reservation_lock);
216 	if (!dev->dev_reserved_node_acl || !sess)
217 		goto out_unlock;
218 
219 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
220 		goto out_unlock;
221 
222 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
223 		goto out_unlock;
224 
225 	dev->dev_reserved_node_acl = NULL;
226 	dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
227 	if (dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID) {
228 		dev->dev_res_bin_isid = 0;
229 		dev->dev_flags &= ~DF_SPC2_RESERVATIONS_WITH_ISID;
230 	}
231 	tpg = sess->se_tpg;
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 		target_complete_cmd(cmd, GOOD);
242 	return ret;
243 }
244 
245 int target_scsi2_reservation_reserve(struct se_cmd *cmd)
246 {
247 	struct se_device *dev = cmd->se_dev;
248 	struct se_session *sess = cmd->se_sess;
249 	struct se_portal_group *tpg;
250 	int ret = 0, rc;
251 
252 	if ((cmd->t_task_cdb[1] & 0x01) &&
253 	    (cmd->t_task_cdb[1] & 0x02)) {
254 		pr_err("LongIO and Obselete Bits set, returning"
255 				" ILLEGAL_REQUEST\n");
256 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
257 		ret = -EINVAL;
258 		goto out;
259 	}
260 	/*
261 	 * This is currently the case for target_core_mod passthrough struct se_cmd
262 	 * ops
263 	 */
264 	if (!sess || !sess->se_tpg)
265 		goto out;
266 	rc = target_check_scsi2_reservation_conflict(cmd);
267 	if (rc == 1)
268 		goto out;
269 	else if (rc < 0) {
270 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
271 		ret = -EINVAL;
272 		goto out;
273 	}
274 
275 	ret = 0;
276 	tpg = sess->se_tpg;
277 	spin_lock(&dev->dev_reservation_lock);
278 	if (dev->dev_reserved_node_acl &&
279 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
280 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
281 			tpg->se_tpg_tfo->get_fabric_name());
282 		pr_err("Original reserver LUN: %u %s\n",
283 			cmd->se_lun->unpacked_lun,
284 			dev->dev_reserved_node_acl->initiatorname);
285 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
286 			" from %s \n", cmd->se_lun->unpacked_lun,
287 			cmd->se_deve->mapped_lun,
288 			sess->se_node_acl->initiatorname);
289 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
290 		ret = -EINVAL;
291 		goto out_unlock;
292 	}
293 
294 	dev->dev_reserved_node_acl = sess->se_node_acl;
295 	dev->dev_flags |= DF_SPC2_RESERVATIONS;
296 	if (sess->sess_bin_isid != 0) {
297 		dev->dev_res_bin_isid = sess->sess_bin_isid;
298 		dev->dev_flags |= DF_SPC2_RESERVATIONS_WITH_ISID;
299 	}
300 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
301 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
302 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
303 		sess->se_node_acl->initiatorname);
304 
305 out_unlock:
306 	spin_unlock(&dev->dev_reservation_lock);
307 out:
308 	if (!ret)
309 		target_complete_cmd(cmd, GOOD);
310 	return ret;
311 }
312 
313 
314 /*
315  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
316  *
317  * This function is called by those initiator ports who are *NOT*
318  * the active PR reservation holder when a reservation is present.
319  */
320 static int core_scsi3_pr_seq_non_holder(
321 	struct se_cmd *cmd,
322 	unsigned char *cdb,
323 	u32 pr_reg_type)
324 {
325 	struct se_dev_entry *se_deve;
326 	struct se_session *se_sess = cmd->se_sess;
327 	int other_cdb = 0, ignore_reg;
328 	int registered_nexus = 0, ret = 1; /* Conflict by default */
329 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
330 	int we = 0; /* Write Exclusive */
331 	int legacy = 0; /* Act like a legacy device and return
332 			 * RESERVATION CONFLICT on some CDBs */
333 	/*
334 	 * A legacy SPC-2 reservation is being held.
335 	 */
336 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS)
337 		return core_scsi2_reservation_seq_non_holder(cmd,
338 					cdb, pr_reg_type);
339 
340 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
341 	/*
342 	 * Determine if the registration should be ignored due to
343 	 * non-matching ISIDs in core_scsi3_pr_reservation_check().
344 	 */
345 	ignore_reg = (pr_reg_type & 0x80000000);
346 	if (ignore_reg)
347 		pr_reg_type &= ~0x80000000;
348 
349 	switch (pr_reg_type) {
350 	case PR_TYPE_WRITE_EXCLUSIVE:
351 		we = 1;
352 	case PR_TYPE_EXCLUSIVE_ACCESS:
353 		/*
354 		 * Some commands are only allowed for the persistent reservation
355 		 * holder.
356 		 */
357 		if ((se_deve->def_pr_registered) && !(ignore_reg))
358 			registered_nexus = 1;
359 		break;
360 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
361 		we = 1;
362 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
363 		/*
364 		 * Some commands are only allowed for registered I_T Nexuses.
365 		 */
366 		reg_only = 1;
367 		if ((se_deve->def_pr_registered) && !(ignore_reg))
368 			registered_nexus = 1;
369 		break;
370 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
371 		we = 1;
372 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
373 		/*
374 		 * Each registered I_T Nexus is a reservation holder.
375 		 */
376 		all_reg = 1;
377 		if ((se_deve->def_pr_registered) && !(ignore_reg))
378 			registered_nexus = 1;
379 		break;
380 	default:
381 		return -EINVAL;
382 	}
383 	/*
384 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
385 	 */
386 	switch (cdb[0]) {
387 	case SECURITY_PROTOCOL_IN:
388 		if (registered_nexus)
389 			return 0;
390 		ret = (we) ? 0 : 1;
391 		break;
392 	case MODE_SENSE:
393 	case MODE_SENSE_10:
394 	case READ_ATTRIBUTE:
395 	case READ_BUFFER:
396 	case RECEIVE_DIAGNOSTIC:
397 		if (legacy) {
398 			ret = 1;
399 			break;
400 		}
401 		if (registered_nexus) {
402 			ret = 0;
403 			break;
404 		}
405 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
406 		break;
407 	case PERSISTENT_RESERVE_OUT:
408 		/*
409 		 * This follows PERSISTENT_RESERVE_OUT service actions that
410 		 * are allowed in the presence of various reservations.
411 		 * See spc4r17, table 46
412 		 */
413 		switch (cdb[1] & 0x1f) {
414 		case PRO_CLEAR:
415 		case PRO_PREEMPT:
416 		case PRO_PREEMPT_AND_ABORT:
417 			ret = (registered_nexus) ? 0 : 1;
418 			break;
419 		case PRO_REGISTER:
420 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
421 			ret = 0;
422 			break;
423 		case PRO_REGISTER_AND_MOVE:
424 		case PRO_RESERVE:
425 			ret = 1;
426 			break;
427 		case PRO_RELEASE:
428 			ret = (registered_nexus) ? 0 : 1;
429 			break;
430 		default:
431 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
432 				" action: 0x%02x\n", cdb[1] & 0x1f);
433 			return -EINVAL;
434 		}
435 		break;
436 	case RELEASE:
437 	case RELEASE_10:
438 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
439 		ret = 0;
440 		break;
441 	case RESERVE:
442 	case RESERVE_10:
443 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
444 		ret = 0;
445 		break;
446 	case TEST_UNIT_READY:
447 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
448 		break;
449 	case MAINTENANCE_IN:
450 		switch (cdb[1] & 0x1f) {
451 		case MI_MANAGEMENT_PROTOCOL_IN:
452 			if (registered_nexus) {
453 				ret = 0;
454 				break;
455 			}
456 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
457 			break;
458 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
459 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
460 			if (legacy) {
461 				ret = 1;
462 				break;
463 			}
464 			if (registered_nexus) {
465 				ret = 0;
466 				break;
467 			}
468 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
469 			break;
470 		case MI_REPORT_ALIASES:
471 		case MI_REPORT_IDENTIFYING_INFORMATION:
472 		case MI_REPORT_PRIORITY:
473 		case MI_REPORT_TARGET_PGS:
474 		case MI_REPORT_TIMESTAMP:
475 			ret = 0; /* Allowed */
476 			break;
477 		default:
478 			pr_err("Unknown MI Service Action: 0x%02x\n",
479 				(cdb[1] & 0x1f));
480 			return -EINVAL;
481 		}
482 		break;
483 	case ACCESS_CONTROL_IN:
484 	case ACCESS_CONTROL_OUT:
485 	case INQUIRY:
486 	case LOG_SENSE:
487 	case READ_MEDIA_SERIAL_NUMBER:
488 	case REPORT_LUNS:
489 	case REQUEST_SENSE:
490 	case PERSISTENT_RESERVE_IN:
491 		ret = 0; /*/ Allowed CDBs */
492 		break;
493 	default:
494 		other_cdb = 1;
495 		break;
496 	}
497 	/*
498 	 * Case where the CDB is explicitly allowed in the above switch
499 	 * statement.
500 	 */
501 	if (!ret && !other_cdb) {
502 		pr_debug("Allowing explict CDB: 0x%02x for %s"
503 			" reservation holder\n", cdb[0],
504 			core_scsi3_pr_dump_type(pr_reg_type));
505 
506 		return ret;
507 	}
508 	/*
509 	 * Check if write exclusive initiator ports *NOT* holding the
510 	 * WRITE_EXCLUSIVE_* reservation.
511 	 */
512 	if (we && !registered_nexus) {
513 		if (cmd->data_direction == DMA_TO_DEVICE) {
514 			/*
515 			 * Conflict for write exclusive
516 			 */
517 			pr_debug("%s Conflict for unregistered nexus"
518 				" %s CDB: 0x%02x to %s reservation\n",
519 				transport_dump_cmd_direction(cmd),
520 				se_sess->se_node_acl->initiatorname, cdb[0],
521 				core_scsi3_pr_dump_type(pr_reg_type));
522 			return 1;
523 		} else {
524 			/*
525 			 * Allow non WRITE CDBs for all Write Exclusive
526 			 * PR TYPEs to pass for registered and
527 			 * non-registered_nexuxes NOT holding the reservation.
528 			 *
529 			 * We only make noise for the unregisterd nexuses,
530 			 * as we expect registered non-reservation holding
531 			 * nexuses to issue CDBs.
532 			 */
533 
534 			if (!registered_nexus) {
535 				pr_debug("Allowing implict CDB: 0x%02x"
536 					" for %s reservation on unregistered"
537 					" nexus\n", cdb[0],
538 					core_scsi3_pr_dump_type(pr_reg_type));
539 			}
540 
541 			return 0;
542 		}
543 	} else if ((reg_only) || (all_reg)) {
544 		if (registered_nexus) {
545 			/*
546 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
547 			 * allow commands from registered nexuses.
548 			 */
549 
550 			pr_debug("Allowing implict CDB: 0x%02x for %s"
551 				" reservation\n", cdb[0],
552 				core_scsi3_pr_dump_type(pr_reg_type));
553 
554 			return 0;
555 		}
556 	}
557 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
558 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
559 		(registered_nexus) ? "" : "un",
560 		se_sess->se_node_acl->initiatorname, cdb[0],
561 		core_scsi3_pr_dump_type(pr_reg_type));
562 
563 	return 1; /* Conflict by default */
564 }
565 
566 static u32 core_scsi3_pr_generation(struct se_device *dev)
567 {
568 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
569 	u32 prg;
570 	/*
571 	 * PRGeneration field shall contain the value of a 32-bit wrapping
572 	 * counter mainted by the device server.
573 	 *
574 	 * Note that this is done regardless of Active Persist across
575 	 * Target PowerLoss (APTPL)
576 	 *
577 	 * See spc4r17 section 6.3.12 READ_KEYS service action
578 	 */
579 	spin_lock(&dev->dev_reservation_lock);
580 	prg = su_dev->t10_pr.pr_generation++;
581 	spin_unlock(&dev->dev_reservation_lock);
582 
583 	return prg;
584 }
585 
586 static int core_scsi3_pr_reservation_check(
587 	struct se_cmd *cmd,
588 	u32 *pr_reg_type)
589 {
590 	struct se_device *dev = cmd->se_dev;
591 	struct se_session *sess = cmd->se_sess;
592 	int ret;
593 
594 	if (!sess)
595 		return 0;
596 	/*
597 	 * A legacy SPC-2 reservation is being held.
598 	 */
599 	if (dev->dev_flags & DF_SPC2_RESERVATIONS)
600 		return core_scsi2_reservation_check(cmd, pr_reg_type);
601 
602 	spin_lock(&dev->dev_reservation_lock);
603 	if (!dev->dev_pr_res_holder) {
604 		spin_unlock(&dev->dev_reservation_lock);
605 		return 0;
606 	}
607 	*pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
608 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
609 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl) {
610 		spin_unlock(&dev->dev_reservation_lock);
611 		return -EINVAL;
612 	}
613 	if (!dev->dev_pr_res_holder->isid_present_at_reg) {
614 		spin_unlock(&dev->dev_reservation_lock);
615 		return 0;
616 	}
617 	ret = (dev->dev_pr_res_holder->pr_reg_bin_isid ==
618 	       sess->sess_bin_isid) ? 0 : -EINVAL;
619 	/*
620 	 * Use bit in *pr_reg_type to notify ISID mismatch in
621 	 * core_scsi3_pr_seq_non_holder().
622 	 */
623 	if (ret != 0)
624 		*pr_reg_type |= 0x80000000;
625 	spin_unlock(&dev->dev_reservation_lock);
626 
627 	return ret;
628 }
629 
630 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
631 	struct se_device *dev,
632 	struct se_node_acl *nacl,
633 	struct se_dev_entry *deve,
634 	unsigned char *isid,
635 	u64 sa_res_key,
636 	int all_tg_pt,
637 	int aptpl)
638 {
639 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
640 	struct t10_pr_registration *pr_reg;
641 
642 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
643 	if (!pr_reg) {
644 		pr_err("Unable to allocate struct t10_pr_registration\n");
645 		return NULL;
646 	}
647 
648 	pr_reg->pr_aptpl_buf = kzalloc(su_dev->t10_pr.pr_aptpl_buf_len,
649 					GFP_ATOMIC);
650 	if (!pr_reg->pr_aptpl_buf) {
651 		pr_err("Unable to allocate pr_reg->pr_aptpl_buf\n");
652 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
653 		return NULL;
654 	}
655 
656 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
657 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
658 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
659 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
660 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
661 	atomic_set(&pr_reg->pr_res_holders, 0);
662 	pr_reg->pr_reg_nacl = nacl;
663 	pr_reg->pr_reg_deve = deve;
664 	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
665 	pr_reg->pr_aptpl_target_lun = deve->se_lun->unpacked_lun;
666 	pr_reg->pr_res_key = sa_res_key;
667 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
668 	pr_reg->pr_reg_aptpl = aptpl;
669 	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
670 	/*
671 	 * If an ISID value for this SCSI Initiator Port exists,
672 	 * save it to the registration now.
673 	 */
674 	if (isid != NULL) {
675 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
676 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
677 		pr_reg->isid_present_at_reg = 1;
678 	}
679 
680 	return pr_reg;
681 }
682 
683 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
684 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
685 
686 /*
687  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
688  * modes.
689  */
690 static struct t10_pr_registration *__core_scsi3_alloc_registration(
691 	struct se_device *dev,
692 	struct se_node_acl *nacl,
693 	struct se_dev_entry *deve,
694 	unsigned char *isid,
695 	u64 sa_res_key,
696 	int all_tg_pt,
697 	int aptpl)
698 {
699 	struct se_dev_entry *deve_tmp;
700 	struct se_node_acl *nacl_tmp;
701 	struct se_port *port, *port_tmp;
702 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
703 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
704 	int ret;
705 	/*
706 	 * Create a registration for the I_T Nexus upon which the
707 	 * PROUT REGISTER was received.
708 	 */
709 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, deve, isid,
710 			sa_res_key, all_tg_pt, aptpl);
711 	if (!pr_reg)
712 		return NULL;
713 	/*
714 	 * Return pointer to pr_reg for ALL_TG_PT=0
715 	 */
716 	if (!all_tg_pt)
717 		return pr_reg;
718 	/*
719 	 * Create list of matching SCSI Initiator Port registrations
720 	 * for ALL_TG_PT=1
721 	 */
722 	spin_lock(&dev->se_port_lock);
723 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
724 		atomic_inc(&port->sep_tg_pt_ref_cnt);
725 		smp_mb__after_atomic_inc();
726 		spin_unlock(&dev->se_port_lock);
727 
728 		spin_lock_bh(&port->sep_alua_lock);
729 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
730 					alua_port_list) {
731 			/*
732 			 * This pointer will be NULL for demo mode MappedLUNs
733 			 * that have not been make explict via a ConfigFS
734 			 * MappedLUN group for the SCSI Initiator Node ACL.
735 			 */
736 			if (!deve_tmp->se_lun_acl)
737 				continue;
738 
739 			nacl_tmp = deve_tmp->se_lun_acl->se_lun_nacl;
740 			/*
741 			 * Skip the matching struct se_node_acl that is allocated
742 			 * above..
743 			 */
744 			if (nacl == nacl_tmp)
745 				continue;
746 			/*
747 			 * Only perform PR registrations for target ports on
748 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
749 			 * arrived.
750 			 */
751 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
752 				continue;
753 			/*
754 			 * Look for a matching Initiator Node ACL in ASCII format
755 			 */
756 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
757 				continue;
758 
759 			atomic_inc(&deve_tmp->pr_ref_count);
760 			smp_mb__after_atomic_inc();
761 			spin_unlock_bh(&port->sep_alua_lock);
762 			/*
763 			 * Grab a configfs group dependency that is released
764 			 * for the exception path at label out: below, or upon
765 			 * completion of adding ALL_TG_PT=1 registrations in
766 			 * __core_scsi3_add_registration()
767 			 */
768 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
769 			if (ret < 0) {
770 				pr_err("core_scsi3_lunacl_depend"
771 						"_item() failed\n");
772 				atomic_dec(&port->sep_tg_pt_ref_cnt);
773 				smp_mb__after_atomic_dec();
774 				atomic_dec(&deve_tmp->pr_ref_count);
775 				smp_mb__after_atomic_dec();
776 				goto out;
777 			}
778 			/*
779 			 * Located a matching SCSI Initiator Port on a different
780 			 * port, allocate the pr_reg_atp and attach it to the
781 			 * pr_reg->pr_reg_atp_list that will be processed once
782 			 * the original *pr_reg is processed in
783 			 * __core_scsi3_add_registration()
784 			 */
785 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
786 						nacl_tmp, deve_tmp, NULL,
787 						sa_res_key, all_tg_pt, aptpl);
788 			if (!pr_reg_atp) {
789 				atomic_dec(&port->sep_tg_pt_ref_cnt);
790 				smp_mb__after_atomic_dec();
791 				atomic_dec(&deve_tmp->pr_ref_count);
792 				smp_mb__after_atomic_dec();
793 				core_scsi3_lunacl_undepend_item(deve_tmp);
794 				goto out;
795 			}
796 
797 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
798 				      &pr_reg->pr_reg_atp_list);
799 			spin_lock_bh(&port->sep_alua_lock);
800 		}
801 		spin_unlock_bh(&port->sep_alua_lock);
802 
803 		spin_lock(&dev->se_port_lock);
804 		atomic_dec(&port->sep_tg_pt_ref_cnt);
805 		smp_mb__after_atomic_dec();
806 	}
807 	spin_unlock(&dev->se_port_lock);
808 
809 	return pr_reg;
810 out:
811 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
812 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
813 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
814 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
815 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
816 	}
817 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
818 	return NULL;
819 }
820 
821 int core_scsi3_alloc_aptpl_registration(
822 	struct t10_reservation *pr_tmpl,
823 	u64 sa_res_key,
824 	unsigned char *i_port,
825 	unsigned char *isid,
826 	u32 mapped_lun,
827 	unsigned char *t_port,
828 	u16 tpgt,
829 	u32 target_lun,
830 	int res_holder,
831 	int all_tg_pt,
832 	u8 type)
833 {
834 	struct t10_pr_registration *pr_reg;
835 
836 	if (!i_port || !t_port || !sa_res_key) {
837 		pr_err("Illegal parameters for APTPL registration\n");
838 		return -EINVAL;
839 	}
840 
841 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
842 	if (!pr_reg) {
843 		pr_err("Unable to allocate struct t10_pr_registration\n");
844 		return -ENOMEM;
845 	}
846 	pr_reg->pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len, GFP_KERNEL);
847 
848 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
849 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
850 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
851 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
852 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
853 	atomic_set(&pr_reg->pr_res_holders, 0);
854 	pr_reg->pr_reg_nacl = NULL;
855 	pr_reg->pr_reg_deve = NULL;
856 	pr_reg->pr_res_mapped_lun = mapped_lun;
857 	pr_reg->pr_aptpl_target_lun = target_lun;
858 	pr_reg->pr_res_key = sa_res_key;
859 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
860 	pr_reg->pr_reg_aptpl = 1;
861 	pr_reg->pr_reg_tg_pt_lun = NULL;
862 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
863 	pr_reg->pr_res_type = type;
864 	/*
865 	 * If an ISID value had been saved in APTPL metadata for this
866 	 * SCSI Initiator Port, restore it now.
867 	 */
868 	if (isid != NULL) {
869 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
870 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
871 		pr_reg->isid_present_at_reg = 1;
872 	}
873 	/*
874 	 * Copy the i_port and t_port information from caller.
875 	 */
876 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
877 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
878 	pr_reg->pr_reg_tpgt = tpgt;
879 	/*
880 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
881 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
882 	 * the Initiator Node LUN ACL from the fabric module is created for
883 	 * this registration.
884 	 */
885 	pr_reg->pr_res_holder = res_holder;
886 
887 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
888 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
889 			" metadata\n", (res_holder) ? "+reservation" : "");
890 	return 0;
891 }
892 
893 static void core_scsi3_aptpl_reserve(
894 	struct se_device *dev,
895 	struct se_portal_group *tpg,
896 	struct se_node_acl *node_acl,
897 	struct t10_pr_registration *pr_reg)
898 {
899 	char i_buf[PR_REG_ISID_ID_LEN];
900 	int prf_isid;
901 
902 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
903 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
904 				PR_REG_ISID_ID_LEN);
905 
906 	spin_lock(&dev->dev_reservation_lock);
907 	dev->dev_pr_res_holder = pr_reg;
908 	spin_unlock(&dev->dev_reservation_lock);
909 
910 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
911 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
912 		tpg->se_tpg_tfo->get_fabric_name(),
913 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
914 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
915 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
916 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
917 		(prf_isid) ? &i_buf[0] : "");
918 }
919 
920 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
921 				struct t10_pr_registration *, int, int);
922 
923 static int __core_scsi3_check_aptpl_registration(
924 	struct se_device *dev,
925 	struct se_portal_group *tpg,
926 	struct se_lun *lun,
927 	u32 target_lun,
928 	struct se_node_acl *nacl,
929 	struct se_dev_entry *deve)
930 {
931 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
932 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
933 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
934 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
935 	u16 tpgt;
936 
937 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
938 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
939 	/*
940 	 * Copy Initiator Port information from struct se_node_acl
941 	 */
942 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
943 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
944 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
945 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
946 	/*
947 	 * Look for the matching registrations+reservation from those
948 	 * created from APTPL metadata.  Note that multiple registrations
949 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
950 	 * TransportIDs.
951 	 */
952 	spin_lock(&pr_tmpl->aptpl_reg_lock);
953 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
954 				pr_reg_aptpl_list) {
955 		if (!strcmp(pr_reg->pr_iport, i_port) &&
956 		     (pr_reg->pr_res_mapped_lun == deve->mapped_lun) &&
957 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
958 		     (pr_reg->pr_reg_tpgt == tpgt) &&
959 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
960 
961 			pr_reg->pr_reg_nacl = nacl;
962 			pr_reg->pr_reg_deve = deve;
963 			pr_reg->pr_reg_tg_pt_lun = lun;
964 
965 			list_del(&pr_reg->pr_reg_aptpl_list);
966 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
967 			/*
968 			 * At this point all of the pointers in *pr_reg will
969 			 * be setup, so go ahead and add the registration.
970 			 */
971 
972 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
973 			/*
974 			 * If this registration is the reservation holder,
975 			 * make that happen now..
976 			 */
977 			if (pr_reg->pr_res_holder)
978 				core_scsi3_aptpl_reserve(dev, tpg,
979 						nacl, pr_reg);
980 			/*
981 			 * Reenable pr_aptpl_active to accept new metadata
982 			 * updates once the SCSI device is active again..
983 			 */
984 			spin_lock(&pr_tmpl->aptpl_reg_lock);
985 			pr_tmpl->pr_aptpl_active = 1;
986 		}
987 	}
988 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
989 
990 	return 0;
991 }
992 
993 int core_scsi3_check_aptpl_registration(
994 	struct se_device *dev,
995 	struct se_portal_group *tpg,
996 	struct se_lun *lun,
997 	struct se_lun_acl *lun_acl)
998 {
999 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1000 	struct se_node_acl *nacl = lun_acl->se_lun_nacl;
1001 	struct se_dev_entry *deve = nacl->device_list[lun_acl->mapped_lun];
1002 
1003 	if (su_dev->t10_pr.res_type != SPC3_PERSISTENT_RESERVATIONS)
1004 		return 0;
1005 
1006 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
1007 				lun->unpacked_lun, nacl, deve);
1008 }
1009 
1010 static void __core_scsi3_dump_registration(
1011 	struct target_core_fabric_ops *tfo,
1012 	struct se_device *dev,
1013 	struct se_node_acl *nacl,
1014 	struct t10_pr_registration *pr_reg,
1015 	int register_type)
1016 {
1017 	struct se_portal_group *se_tpg = nacl->se_tpg;
1018 	char i_buf[PR_REG_ISID_ID_LEN];
1019 	int prf_isid;
1020 
1021 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
1022 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1023 				PR_REG_ISID_ID_LEN);
1024 
1025 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1026 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == 2) ?
1027 		"_AND_MOVE" : (register_type == 1) ?
1028 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1029 		(prf_isid) ? i_buf : "");
1030 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1031 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
1032 		tfo->tpg_get_tag(se_tpg));
1033 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1034 		" Port(s)\n",  tfo->get_fabric_name(),
1035 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1036 		dev->transport->name);
1037 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1038 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
1039 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1040 		pr_reg->pr_reg_aptpl);
1041 }
1042 
1043 /*
1044  * this function can be called with struct se_device->dev_reservation_lock
1045  * when register_move = 1
1046  */
1047 static void __core_scsi3_add_registration(
1048 	struct se_device *dev,
1049 	struct se_node_acl *nacl,
1050 	struct t10_pr_registration *pr_reg,
1051 	int register_type,
1052 	int register_move)
1053 {
1054 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1055 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1056 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1057 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1058 
1059 	/*
1060 	 * Increment PRgeneration counter for struct se_device upon a successful
1061 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1062 	 *
1063 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1064 	 * action, the struct se_device->dev_reservation_lock will already be held,
1065 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1066 	 * for the REGISTER.
1067 	 */
1068 	pr_reg->pr_res_generation = (register_move) ?
1069 			su_dev->t10_pr.pr_generation++ :
1070 			core_scsi3_pr_generation(dev);
1071 
1072 	spin_lock(&pr_tmpl->registration_lock);
1073 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1074 	pr_reg->pr_reg_deve->def_pr_registered = 1;
1075 
1076 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1077 	spin_unlock(&pr_tmpl->registration_lock);
1078 	/*
1079 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1080 	 */
1081 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1082 		return;
1083 	/*
1084 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1085 	 * allocated in __core_scsi3_alloc_registration()
1086 	 */
1087 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1088 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1089 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1090 
1091 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1092 
1093 		spin_lock(&pr_tmpl->registration_lock);
1094 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1095 			      &pr_tmpl->registration_list);
1096 		pr_reg_tmp->pr_reg_deve->def_pr_registered = 1;
1097 
1098 		__core_scsi3_dump_registration(tfo, dev,
1099 				pr_reg_tmp->pr_reg_nacl, pr_reg_tmp,
1100 				register_type);
1101 		spin_unlock(&pr_tmpl->registration_lock);
1102 		/*
1103 		 * Drop configfs group dependency reference from
1104 		 * __core_scsi3_alloc_registration()
1105 		 */
1106 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1107 	}
1108 }
1109 
1110 static int core_scsi3_alloc_registration(
1111 	struct se_device *dev,
1112 	struct se_node_acl *nacl,
1113 	struct se_dev_entry *deve,
1114 	unsigned char *isid,
1115 	u64 sa_res_key,
1116 	int all_tg_pt,
1117 	int aptpl,
1118 	int register_type,
1119 	int register_move)
1120 {
1121 	struct t10_pr_registration *pr_reg;
1122 
1123 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, deve, isid,
1124 			sa_res_key, all_tg_pt, aptpl);
1125 	if (!pr_reg)
1126 		return -EPERM;
1127 
1128 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1129 			register_type, register_move);
1130 	return 0;
1131 }
1132 
1133 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1134 	struct se_device *dev,
1135 	struct se_node_acl *nacl,
1136 	unsigned char *isid)
1137 {
1138 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1139 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1140 	struct se_portal_group *tpg;
1141 
1142 	spin_lock(&pr_tmpl->registration_lock);
1143 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1144 			&pr_tmpl->registration_list, pr_reg_list) {
1145 		/*
1146 		 * First look for a matching struct se_node_acl
1147 		 */
1148 		if (pr_reg->pr_reg_nacl != nacl)
1149 			continue;
1150 
1151 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1152 		/*
1153 		 * If this registration does NOT contain a fabric provided
1154 		 * ISID, then we have found a match.
1155 		 */
1156 		if (!pr_reg->isid_present_at_reg) {
1157 			/*
1158 			 * Determine if this SCSI device server requires that
1159 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1160 			 * for fabric modules (iSCSI) requiring them.
1161 			 */
1162 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1163 				if (dev->se_sub_dev->se_dev_attrib.enforce_pr_isids)
1164 					continue;
1165 			}
1166 			atomic_inc(&pr_reg->pr_res_holders);
1167 			smp_mb__after_atomic_inc();
1168 			spin_unlock(&pr_tmpl->registration_lock);
1169 			return pr_reg;
1170 		}
1171 		/*
1172 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1173 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1174 		 * matching ISID to be provided by the local SCSI Initiator Port.
1175 		 */
1176 		if (!isid)
1177 			continue;
1178 		if (strcmp(isid, pr_reg->pr_reg_isid))
1179 			continue;
1180 
1181 		atomic_inc(&pr_reg->pr_res_holders);
1182 		smp_mb__after_atomic_inc();
1183 		spin_unlock(&pr_tmpl->registration_lock);
1184 		return pr_reg;
1185 	}
1186 	spin_unlock(&pr_tmpl->registration_lock);
1187 
1188 	return NULL;
1189 }
1190 
1191 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1192 	struct se_device *dev,
1193 	struct se_node_acl *nacl,
1194 	struct se_session *sess)
1195 {
1196 	struct se_portal_group *tpg = nacl->se_tpg;
1197 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1198 
1199 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1200 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1201 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1202 					PR_REG_ISID_LEN);
1203 		isid_ptr = &buf[0];
1204 	}
1205 
1206 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1207 }
1208 
1209 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1210 {
1211 	atomic_dec(&pr_reg->pr_res_holders);
1212 	smp_mb__after_atomic_dec();
1213 }
1214 
1215 static int core_scsi3_check_implict_release(
1216 	struct se_device *dev,
1217 	struct t10_pr_registration *pr_reg)
1218 {
1219 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1220 	struct t10_pr_registration *pr_res_holder;
1221 	int ret = 0;
1222 
1223 	spin_lock(&dev->dev_reservation_lock);
1224 	pr_res_holder = dev->dev_pr_res_holder;
1225 	if (!pr_res_holder) {
1226 		spin_unlock(&dev->dev_reservation_lock);
1227 		return ret;
1228 	}
1229 	if (pr_res_holder == pr_reg) {
1230 		/*
1231 		 * Perform an implict RELEASE if the registration that
1232 		 * is being released is holding the reservation.
1233 		 *
1234 		 * From spc4r17, section 5.7.11.1:
1235 		 *
1236 		 * e) If the I_T nexus is the persistent reservation holder
1237 		 *    and the persistent reservation is not an all registrants
1238 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1239 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1240 		 *    service action with the SERVICE ACTION RESERVATION KEY
1241 		 *    field set to zero (see 5.7.11.3).
1242 		 */
1243 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0);
1244 		ret = 1;
1245 		/*
1246 		 * For 'All Registrants' reservation types, all existing
1247 		 * registrations are still processed as reservation holders
1248 		 * in core_scsi3_pr_seq_non_holder() after the initial
1249 		 * reservation holder is implictly released here.
1250 		 */
1251 	} else if (pr_reg->pr_reg_all_tg_pt &&
1252 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1253 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1254 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1255 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1256 			" UNREGISTER while existing reservation with matching"
1257 			" key 0x%016Lx is present from another SCSI Initiator"
1258 			" Port\n", pr_reg->pr_res_key);
1259 		ret = -EPERM;
1260 	}
1261 	spin_unlock(&dev->dev_reservation_lock);
1262 
1263 	return ret;
1264 }
1265 
1266 /*
1267  * Called with struct t10_reservation->registration_lock held.
1268  */
1269 static void __core_scsi3_free_registration(
1270 	struct se_device *dev,
1271 	struct t10_pr_registration *pr_reg,
1272 	struct list_head *preempt_and_abort_list,
1273 	int dec_holders)
1274 {
1275 	struct target_core_fabric_ops *tfo =
1276 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1277 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1278 	char i_buf[PR_REG_ISID_ID_LEN];
1279 	int prf_isid;
1280 
1281 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1282 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1283 				PR_REG_ISID_ID_LEN);
1284 
1285 	pr_reg->pr_reg_deve->def_pr_registered = 0;
1286 	pr_reg->pr_reg_deve->pr_res_key = 0;
1287 	list_del(&pr_reg->pr_reg_list);
1288 	/*
1289 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1290 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1291 	 */
1292 	if (dec_holders)
1293 		core_scsi3_put_pr_reg(pr_reg);
1294 	/*
1295 	 * Wait until all reference from any other I_T nexuses for this
1296 	 * *pr_reg have been released.  Because list_del() is called above,
1297 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1298 	 * count back to zero, and we release *pr_reg.
1299 	 */
1300 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1301 		spin_unlock(&pr_tmpl->registration_lock);
1302 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1303 				tfo->get_fabric_name());
1304 		cpu_relax();
1305 		spin_lock(&pr_tmpl->registration_lock);
1306 	}
1307 
1308 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1309 		" Node: %s%s\n", tfo->get_fabric_name(),
1310 		pr_reg->pr_reg_nacl->initiatorname,
1311 		(prf_isid) ? &i_buf[0] : "");
1312 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1313 		" Port(s)\n", tfo->get_fabric_name(),
1314 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1315 		dev->transport->name);
1316 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1317 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1318 		pr_reg->pr_res_generation);
1319 
1320 	if (!preempt_and_abort_list) {
1321 		pr_reg->pr_reg_deve = NULL;
1322 		pr_reg->pr_reg_nacl = NULL;
1323 		kfree(pr_reg->pr_aptpl_buf);
1324 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1325 		return;
1326 	}
1327 	/*
1328 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1329 	 * are released once the ABORT_TASK_SET has completed..
1330 	 */
1331 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1332 }
1333 
1334 void core_scsi3_free_pr_reg_from_nacl(
1335 	struct se_device *dev,
1336 	struct se_node_acl *nacl)
1337 {
1338 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1339 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1340 	/*
1341 	 * If the passed se_node_acl matches the reservation holder,
1342 	 * release the reservation.
1343 	 */
1344 	spin_lock(&dev->dev_reservation_lock);
1345 	pr_res_holder = dev->dev_pr_res_holder;
1346 	if ((pr_res_holder != NULL) &&
1347 	    (pr_res_holder->pr_reg_nacl == nacl))
1348 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0);
1349 	spin_unlock(&dev->dev_reservation_lock);
1350 	/*
1351 	 * Release any registration associated with the struct se_node_acl.
1352 	 */
1353 	spin_lock(&pr_tmpl->registration_lock);
1354 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1355 			&pr_tmpl->registration_list, pr_reg_list) {
1356 
1357 		if (pr_reg->pr_reg_nacl != nacl)
1358 			continue;
1359 
1360 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1361 	}
1362 	spin_unlock(&pr_tmpl->registration_lock);
1363 }
1364 
1365 void core_scsi3_free_all_registrations(
1366 	struct se_device *dev)
1367 {
1368 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1369 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1370 
1371 	spin_lock(&dev->dev_reservation_lock);
1372 	pr_res_holder = dev->dev_pr_res_holder;
1373 	if (pr_res_holder != NULL) {
1374 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1375 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1376 				pr_res_holder, 0);
1377 	}
1378 	spin_unlock(&dev->dev_reservation_lock);
1379 
1380 	spin_lock(&pr_tmpl->registration_lock);
1381 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1382 			&pr_tmpl->registration_list, pr_reg_list) {
1383 
1384 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1385 	}
1386 	spin_unlock(&pr_tmpl->registration_lock);
1387 
1388 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1389 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1390 				pr_reg_aptpl_list) {
1391 		list_del(&pr_reg->pr_reg_aptpl_list);
1392 		kfree(pr_reg->pr_aptpl_buf);
1393 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1394 	}
1395 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1396 }
1397 
1398 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1399 {
1400 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1401 			&tpg->tpg_group.cg_item);
1402 }
1403 
1404 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1405 {
1406 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1407 			&tpg->tpg_group.cg_item);
1408 
1409 	atomic_dec(&tpg->tpg_pr_ref_count);
1410 	smp_mb__after_atomic_dec();
1411 }
1412 
1413 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1414 {
1415 	struct se_portal_group *tpg = nacl->se_tpg;
1416 
1417 	if (nacl->dynamic_node_acl)
1418 		return 0;
1419 
1420 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1421 			&nacl->acl_group.cg_item);
1422 }
1423 
1424 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1425 {
1426 	struct se_portal_group *tpg = nacl->se_tpg;
1427 
1428 	if (nacl->dynamic_node_acl) {
1429 		atomic_dec(&nacl->acl_pr_ref_count);
1430 		smp_mb__after_atomic_dec();
1431 		return;
1432 	}
1433 
1434 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1435 			&nacl->acl_group.cg_item);
1436 
1437 	atomic_dec(&nacl->acl_pr_ref_count);
1438 	smp_mb__after_atomic_dec();
1439 }
1440 
1441 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1442 {
1443 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1444 	struct se_node_acl *nacl;
1445 	struct se_portal_group *tpg;
1446 	/*
1447 	 * For nacl->dynamic_node_acl=1
1448 	 */
1449 	if (!lun_acl)
1450 		return 0;
1451 
1452 	nacl = lun_acl->se_lun_nacl;
1453 	tpg = nacl->se_tpg;
1454 
1455 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1456 			&lun_acl->se_lun_group.cg_item);
1457 }
1458 
1459 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1460 {
1461 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1462 	struct se_node_acl *nacl;
1463 	struct se_portal_group *tpg;
1464 	/*
1465 	 * For nacl->dynamic_node_acl=1
1466 	 */
1467 	if (!lun_acl) {
1468 		atomic_dec(&se_deve->pr_ref_count);
1469 		smp_mb__after_atomic_dec();
1470 		return;
1471 	}
1472 	nacl = lun_acl->se_lun_nacl;
1473 	tpg = nacl->se_tpg;
1474 
1475 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1476 			&lun_acl->se_lun_group.cg_item);
1477 
1478 	atomic_dec(&se_deve->pr_ref_count);
1479 	smp_mb__after_atomic_dec();
1480 }
1481 
1482 static int core_scsi3_decode_spec_i_port(
1483 	struct se_cmd *cmd,
1484 	struct se_portal_group *tpg,
1485 	unsigned char *l_isid,
1486 	u64 sa_res_key,
1487 	int all_tg_pt,
1488 	int aptpl)
1489 {
1490 	struct se_device *dev = cmd->se_dev;
1491 	struct se_port *tmp_port;
1492 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1493 	struct se_session *se_sess = cmd->se_sess;
1494 	struct se_node_acl *dest_node_acl = NULL;
1495 	struct se_dev_entry *dest_se_deve = NULL, *local_se_deve;
1496 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1497 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1498 	LIST_HEAD(tid_dest_list);
1499 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1500 	struct target_core_fabric_ops *tmp_tf_ops;
1501 	unsigned char *buf;
1502 	unsigned char *ptr, *i_str = NULL, proto_ident, tmp_proto_ident;
1503 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
1504 	u32 tpdl, tid_len = 0;
1505 	int ret, dest_local_nexus, prf_isid;
1506 	u32 dest_rtpi = 0;
1507 
1508 	memset(dest_iport, 0, 64);
1509 
1510 	local_se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
1511 	/*
1512 	 * Allocate a struct pr_transport_id_holder and setup the
1513 	 * local_node_acl and local_se_deve pointers and add to
1514 	 * struct list_head tid_dest_list for add registration
1515 	 * processing in the loop of tid_dest_list below.
1516 	 */
1517 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1518 	if (!tidh_new) {
1519 		pr_err("Unable to allocate tidh_new\n");
1520 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1521 		return -EINVAL;
1522 	}
1523 	INIT_LIST_HEAD(&tidh_new->dest_list);
1524 	tidh_new->dest_tpg = tpg;
1525 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1526 	tidh_new->dest_se_deve = local_se_deve;
1527 
1528 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1529 				se_sess->se_node_acl, local_se_deve, l_isid,
1530 				sa_res_key, all_tg_pt, aptpl);
1531 	if (!local_pr_reg) {
1532 		kfree(tidh_new);
1533 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1534 		return -ENOMEM;
1535 	}
1536 	tidh_new->dest_pr_reg = local_pr_reg;
1537 	/*
1538 	 * The local I_T nexus does not hold any configfs dependances,
1539 	 * so we set tid_h->dest_local_nexus=1 to prevent the
1540 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1541 	 */
1542 	tidh_new->dest_local_nexus = 1;
1543 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1544 
1545 	if (cmd->data_length < 28) {
1546 		pr_warn("SPC-PR: Received PR OUT parameter list"
1547 			" length too small: %u\n", cmd->data_length);
1548 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1549 		ret = -EINVAL;
1550 		goto out;
1551 	}
1552 
1553 	buf = transport_kmap_data_sg(cmd);
1554 	/*
1555 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1556 	 * first extract TransportID Parameter Data Length, and make sure
1557 	 * the value matches up to the SCSI expected data transfer length.
1558 	 */
1559 	tpdl = (buf[24] & 0xff) << 24;
1560 	tpdl |= (buf[25] & 0xff) << 16;
1561 	tpdl |= (buf[26] & 0xff) << 8;
1562 	tpdl |= buf[27] & 0xff;
1563 
1564 	if ((tpdl + 28) != cmd->data_length) {
1565 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1566 			" does not equal CDB data_length: %u\n", tpdl,
1567 			cmd->data_length);
1568 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1569 		ret = -EINVAL;
1570 		goto out;
1571 	}
1572 	/*
1573 	 * Start processing the received transport IDs using the
1574 	 * receiving I_T Nexus portal's fabric dependent methods to
1575 	 * obtain the SCSI Initiator Port/Device Identifiers.
1576 	 */
1577 	ptr = &buf[28];
1578 
1579 	while (tpdl > 0) {
1580 		proto_ident = (ptr[0] & 0x0f);
1581 		dest_tpg = NULL;
1582 
1583 		spin_lock(&dev->se_port_lock);
1584 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1585 			tmp_tpg = tmp_port->sep_tpg;
1586 			if (!tmp_tpg)
1587 				continue;
1588 			tmp_tf_ops = tmp_tpg->se_tpg_tfo;
1589 			if (!tmp_tf_ops)
1590 				continue;
1591 			if (!tmp_tf_ops->get_fabric_proto_ident ||
1592 			    !tmp_tf_ops->tpg_parse_pr_out_transport_id)
1593 				continue;
1594 			/*
1595 			 * Look for the matching proto_ident provided by
1596 			 * the received TransportID
1597 			 */
1598 			tmp_proto_ident = tmp_tf_ops->get_fabric_proto_ident(tmp_tpg);
1599 			if (tmp_proto_ident != proto_ident)
1600 				continue;
1601 			dest_rtpi = tmp_port->sep_rtpi;
1602 
1603 			i_str = tmp_tf_ops->tpg_parse_pr_out_transport_id(
1604 					tmp_tpg, (const char *)ptr, &tid_len,
1605 					&iport_ptr);
1606 			if (!i_str)
1607 				continue;
1608 
1609 			atomic_inc(&tmp_tpg->tpg_pr_ref_count);
1610 			smp_mb__after_atomic_inc();
1611 			spin_unlock(&dev->se_port_lock);
1612 
1613 			ret = core_scsi3_tpg_depend_item(tmp_tpg);
1614 			if (ret != 0) {
1615 				pr_err(" core_scsi3_tpg_depend_item()"
1616 					" for tmp_tpg\n");
1617 				atomic_dec(&tmp_tpg->tpg_pr_ref_count);
1618 				smp_mb__after_atomic_dec();
1619 				cmd->scsi_sense_reason =
1620 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1621 				ret = -EINVAL;
1622 				goto out;
1623 			}
1624 			/*
1625 			 * Locate the destination initiator ACL to be registered
1626 			 * from the decoded fabric module specific TransportID
1627 			 * at *i_str.
1628 			 */
1629 			spin_lock_irq(&tmp_tpg->acl_node_lock);
1630 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1631 						tmp_tpg, i_str);
1632 			if (dest_node_acl) {
1633 				atomic_inc(&dest_node_acl->acl_pr_ref_count);
1634 				smp_mb__after_atomic_inc();
1635 			}
1636 			spin_unlock_irq(&tmp_tpg->acl_node_lock);
1637 
1638 			if (!dest_node_acl) {
1639 				core_scsi3_tpg_undepend_item(tmp_tpg);
1640 				spin_lock(&dev->se_port_lock);
1641 				continue;
1642 			}
1643 
1644 			ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
1645 			if (ret != 0) {
1646 				pr_err("configfs_depend_item() failed"
1647 					" for dest_node_acl->acl_group\n");
1648 				atomic_dec(&dest_node_acl->acl_pr_ref_count);
1649 				smp_mb__after_atomic_dec();
1650 				core_scsi3_tpg_undepend_item(tmp_tpg);
1651 				cmd->scsi_sense_reason =
1652 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1653 				ret = -EINVAL;
1654 				goto out;
1655 			}
1656 
1657 			dest_tpg = tmp_tpg;
1658 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1659 				" %s Port RTPI: %hu\n",
1660 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1661 				dest_node_acl->initiatorname, dest_rtpi);
1662 
1663 			spin_lock(&dev->se_port_lock);
1664 			break;
1665 		}
1666 		spin_unlock(&dev->se_port_lock);
1667 
1668 		if (!dest_tpg) {
1669 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1670 					" dest_tpg\n");
1671 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1672 			ret = -EINVAL;
1673 			goto out;
1674 		}
1675 
1676 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1677 			" tid_len: %d for %s + %s\n",
1678 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1679 			tpdl, tid_len, i_str, iport_ptr);
1680 
1681 		if (tid_len > tpdl) {
1682 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1683 				" %u for Transport ID: %s\n", tid_len, ptr);
1684 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1685 			core_scsi3_tpg_undepend_item(dest_tpg);
1686 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1687 			ret = -EINVAL;
1688 			goto out;
1689 		}
1690 		/*
1691 		 * Locate the desintation struct se_dev_entry pointer for matching
1692 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1693 		 * Target Port.
1694 		 */
1695 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1696 					dest_rtpi);
1697 		if (!dest_se_deve) {
1698 			pr_err("Unable to locate %s dest_se_deve"
1699 				" from destination RTPI: %hu\n",
1700 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1701 				dest_rtpi);
1702 
1703 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1704 			core_scsi3_tpg_undepend_item(dest_tpg);
1705 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1706 			ret = -EINVAL;
1707 			goto out;
1708 		}
1709 
1710 		ret = core_scsi3_lunacl_depend_item(dest_se_deve);
1711 		if (ret < 0) {
1712 			pr_err("core_scsi3_lunacl_depend_item()"
1713 					" failed\n");
1714 			atomic_dec(&dest_se_deve->pr_ref_count);
1715 			smp_mb__after_atomic_dec();
1716 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1717 			core_scsi3_tpg_undepend_item(dest_tpg);
1718 			cmd->scsi_sense_reason =
1719 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1720 			ret = -EINVAL;
1721 			goto out;
1722 		}
1723 
1724 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1725 			" dest_se_deve mapped_lun: %u\n",
1726 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1727 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1728 
1729 		/*
1730 		 * Skip any TransportIDs that already have a registration for
1731 		 * this target port.
1732 		 */
1733 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1734 					iport_ptr);
1735 		if (pr_reg_e) {
1736 			core_scsi3_put_pr_reg(pr_reg_e);
1737 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1738 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1739 			core_scsi3_tpg_undepend_item(dest_tpg);
1740 			ptr += tid_len;
1741 			tpdl -= tid_len;
1742 			tid_len = 0;
1743 			continue;
1744 		}
1745 		/*
1746 		 * Allocate a struct pr_transport_id_holder and setup
1747 		 * the dest_node_acl and dest_se_deve pointers for the
1748 		 * loop below.
1749 		 */
1750 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1751 				GFP_KERNEL);
1752 		if (!tidh_new) {
1753 			pr_err("Unable to allocate tidh_new\n");
1754 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1755 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1756 			core_scsi3_tpg_undepend_item(dest_tpg);
1757 			cmd->scsi_sense_reason =
1758 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1759 			ret = -ENOMEM;
1760 			goto out;
1761 		}
1762 		INIT_LIST_HEAD(&tidh_new->dest_list);
1763 		tidh_new->dest_tpg = dest_tpg;
1764 		tidh_new->dest_node_acl = dest_node_acl;
1765 		tidh_new->dest_se_deve = dest_se_deve;
1766 
1767 		/*
1768 		 * Allocate, but do NOT add the registration for the
1769 		 * TransportID referenced SCSI Initiator port.  This
1770 		 * done because of the following from spc4r17 in section
1771 		 * 6.14.3 wrt SPEC_I_PT:
1772 		 *
1773 		 * "If a registration fails for any initiator port (e.g., if th
1774 		 * logical unit does not have enough resources available to
1775 		 * hold the registration information), no registrations shall be
1776 		 * made, and the command shall be terminated with
1777 		 * CHECK CONDITION status."
1778 		 *
1779 		 * That means we call __core_scsi3_alloc_registration() here,
1780 		 * and then call __core_scsi3_add_registration() in the
1781 		 * 2nd loop which will never fail.
1782 		 */
1783 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1784 				dest_node_acl, dest_se_deve, iport_ptr,
1785 				sa_res_key, all_tg_pt, aptpl);
1786 		if (!dest_pr_reg) {
1787 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1788 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1789 			core_scsi3_tpg_undepend_item(dest_tpg);
1790 			kfree(tidh_new);
1791 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1792 			ret = -EINVAL;
1793 			goto out;
1794 		}
1795 		tidh_new->dest_pr_reg = dest_pr_reg;
1796 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1797 
1798 		ptr += tid_len;
1799 		tpdl -= tid_len;
1800 		tid_len = 0;
1801 
1802 	}
1803 
1804 	transport_kunmap_data_sg(cmd);
1805 
1806 	/*
1807 	 * Go ahead and create a registrations from tid_dest_list for the
1808 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1809 	 * and dest_se_deve.
1810 	 *
1811 	 * The SA Reservation Key from the PROUT is set for the
1812 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1813 	 * means that the TransportID Initiator port will be
1814 	 * registered on all of the target ports in the SCSI target device
1815 	 * ALL_TG_PT=0 means the registration will only be for the
1816 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1817 	 * was received.
1818 	 */
1819 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1820 		dest_tpg = tidh->dest_tpg;
1821 		dest_node_acl = tidh->dest_node_acl;
1822 		dest_se_deve = tidh->dest_se_deve;
1823 		dest_pr_reg = tidh->dest_pr_reg;
1824 		dest_local_nexus = tidh->dest_local_nexus;
1825 
1826 		list_del(&tidh->dest_list);
1827 		kfree(tidh);
1828 
1829 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1830 		prf_isid = core_pr_dump_initiator_port(dest_pr_reg, &i_buf[0],
1831 						PR_REG_ISID_ID_LEN);
1832 
1833 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1834 					dest_pr_reg, 0, 0);
1835 
1836 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1837 			" registered Transport ID for Node: %s%s Mapped LUN:"
1838 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1839 			dest_node_acl->initiatorname, (prf_isid) ?
1840 			&i_buf[0] : "", dest_se_deve->mapped_lun);
1841 
1842 		if (dest_local_nexus)
1843 			continue;
1844 
1845 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1846 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1847 		core_scsi3_tpg_undepend_item(dest_tpg);
1848 	}
1849 
1850 	return 0;
1851 out:
1852 	transport_kunmap_data_sg(cmd);
1853 	/*
1854 	 * For the failure case, release everything from tid_dest_list
1855 	 * including *dest_pr_reg and the configfs dependances..
1856 	 */
1857 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1858 		dest_tpg = tidh->dest_tpg;
1859 		dest_node_acl = tidh->dest_node_acl;
1860 		dest_se_deve = tidh->dest_se_deve;
1861 		dest_pr_reg = tidh->dest_pr_reg;
1862 		dest_local_nexus = tidh->dest_local_nexus;
1863 
1864 		list_del(&tidh->dest_list);
1865 		kfree(tidh);
1866 		/*
1867 		 * Release any extra ALL_TG_PT=1 registrations for
1868 		 * the SPEC_I_PT=1 case.
1869 		 */
1870 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1871 				&dest_pr_reg->pr_reg_atp_list,
1872 				pr_reg_atp_mem_list) {
1873 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1874 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1875 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1876 		}
1877 
1878 		kfree(dest_pr_reg->pr_aptpl_buf);
1879 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1880 
1881 		if (dest_local_nexus)
1882 			continue;
1883 
1884 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1885 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1886 		core_scsi3_tpg_undepend_item(dest_tpg);
1887 	}
1888 	return ret;
1889 }
1890 
1891 /*
1892  * Called with struct se_device->dev_reservation_lock held
1893  */
1894 static int __core_scsi3_update_aptpl_buf(
1895 	struct se_device *dev,
1896 	unsigned char *buf,
1897 	u32 pr_aptpl_buf_len,
1898 	int clear_aptpl_metadata)
1899 {
1900 	struct se_lun *lun;
1901 	struct se_portal_group *tpg;
1902 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1903 	struct t10_pr_registration *pr_reg;
1904 	unsigned char tmp[512], isid_buf[32];
1905 	ssize_t len = 0;
1906 	int reg_count = 0;
1907 
1908 	memset(buf, 0, pr_aptpl_buf_len);
1909 	/*
1910 	 * Called to clear metadata once APTPL has been deactivated.
1911 	 */
1912 	if (clear_aptpl_metadata) {
1913 		snprintf(buf, pr_aptpl_buf_len,
1914 				"No Registrations or Reservations\n");
1915 		return 0;
1916 	}
1917 	/*
1918 	 * Walk the registration list..
1919 	 */
1920 	spin_lock(&su_dev->t10_pr.registration_lock);
1921 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
1922 			pr_reg_list) {
1923 
1924 		tmp[0] = '\0';
1925 		isid_buf[0] = '\0';
1926 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1927 		lun = pr_reg->pr_reg_tg_pt_lun;
1928 		/*
1929 		 * Write out any ISID value to APTPL metadata that was included
1930 		 * in the original registration.
1931 		 */
1932 		if (pr_reg->isid_present_at_reg)
1933 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1934 					pr_reg->pr_reg_isid);
1935 		/*
1936 		 * Include special metadata if the pr_reg matches the
1937 		 * reservation holder.
1938 		 */
1939 		if (dev->dev_pr_res_holder == pr_reg) {
1940 			snprintf(tmp, 512, "PR_REG_START: %d"
1941 				"\ninitiator_fabric=%s\n"
1942 				"initiator_node=%s\n%s"
1943 				"sa_res_key=%llu\n"
1944 				"res_holder=1\nres_type=%02x\n"
1945 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1946 				"mapped_lun=%u\n", reg_count,
1947 				tpg->se_tpg_tfo->get_fabric_name(),
1948 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1949 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1950 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1951 				pr_reg->pr_res_mapped_lun);
1952 		} else {
1953 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1954 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1955 				"sa_res_key=%llu\nres_holder=0\n"
1956 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1957 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1958 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1959 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1960 				pr_reg->pr_res_mapped_lun);
1961 		}
1962 
1963 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1964 			pr_err("Unable to update renaming"
1965 				" APTPL metadata\n");
1966 			spin_unlock(&su_dev->t10_pr.registration_lock);
1967 			return -EMSGSIZE;
1968 		}
1969 		len += sprintf(buf+len, "%s", tmp);
1970 
1971 		/*
1972 		 * Include information about the associated SCSI target port.
1973 		 */
1974 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1975 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1976 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1977 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1978 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1979 			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);
1980 
1981 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1982 			pr_err("Unable to update renaming"
1983 				" APTPL metadata\n");
1984 			spin_unlock(&su_dev->t10_pr.registration_lock);
1985 			return -EMSGSIZE;
1986 		}
1987 		len += sprintf(buf+len, "%s", tmp);
1988 		reg_count++;
1989 	}
1990 	spin_unlock(&su_dev->t10_pr.registration_lock);
1991 
1992 	if (!reg_count)
1993 		len += sprintf(buf+len, "No Registrations or Reservations");
1994 
1995 	return 0;
1996 }
1997 
1998 static int core_scsi3_update_aptpl_buf(
1999 	struct se_device *dev,
2000 	unsigned char *buf,
2001 	u32 pr_aptpl_buf_len,
2002 	int clear_aptpl_metadata)
2003 {
2004 	int ret;
2005 
2006 	spin_lock(&dev->dev_reservation_lock);
2007 	ret = __core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
2008 				clear_aptpl_metadata);
2009 	spin_unlock(&dev->dev_reservation_lock);
2010 
2011 	return ret;
2012 }
2013 
2014 /*
2015  * Called with struct se_device->aptpl_file_mutex held
2016  */
2017 static int __core_scsi3_write_aptpl_to_file(
2018 	struct se_device *dev,
2019 	unsigned char *buf,
2020 	u32 pr_aptpl_buf_len)
2021 {
2022 	struct t10_wwn *wwn = &dev->se_sub_dev->t10_wwn;
2023 	struct file *file;
2024 	struct iovec iov[1];
2025 	mm_segment_t old_fs;
2026 	int flags = O_RDWR | O_CREAT | O_TRUNC;
2027 	char path[512];
2028 	int ret;
2029 
2030 	memset(iov, 0, sizeof(struct iovec));
2031 	memset(path, 0, 512);
2032 
2033 	if (strlen(&wwn->unit_serial[0]) >= 512) {
2034 		pr_err("WWN value for struct se_device does not fit"
2035 			" into path buffer\n");
2036 		return -EMSGSIZE;
2037 	}
2038 
2039 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
2040 	file = filp_open(path, flags, 0600);
2041 	if (IS_ERR(file) || !file || !file->f_dentry) {
2042 		pr_err("filp_open(%s) for APTPL metadata"
2043 			" failed\n", path);
2044 		return IS_ERR(file) ? PTR_ERR(file) : -ENOENT;
2045 	}
2046 
2047 	iov[0].iov_base = &buf[0];
2048 	if (!pr_aptpl_buf_len)
2049 		iov[0].iov_len = (strlen(&buf[0]) + 1); /* Add extra for NULL */
2050 	else
2051 		iov[0].iov_len = pr_aptpl_buf_len;
2052 
2053 	old_fs = get_fs();
2054 	set_fs(get_ds());
2055 	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
2056 	set_fs(old_fs);
2057 
2058 	if (ret < 0) {
2059 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2060 		filp_close(file, NULL);
2061 		return -EIO;
2062 	}
2063 	filp_close(file, NULL);
2064 
2065 	return 0;
2066 }
2067 
2068 static int core_scsi3_update_and_write_aptpl(
2069 	struct se_device *dev,
2070 	unsigned char *in_buf,
2071 	u32 in_pr_aptpl_buf_len)
2072 {
2073 	unsigned char null_buf[64], *buf;
2074 	u32 pr_aptpl_buf_len;
2075 	int ret, clear_aptpl_metadata = 0;
2076 	/*
2077 	 * Can be called with a NULL pointer from PROUT service action CLEAR
2078 	 */
2079 	if (!in_buf) {
2080 		memset(null_buf, 0, 64);
2081 		buf = &null_buf[0];
2082 		/*
2083 		 * This will clear the APTPL metadata to:
2084 		 * "No Registrations or Reservations" status
2085 		 */
2086 		pr_aptpl_buf_len = 64;
2087 		clear_aptpl_metadata = 1;
2088 	} else {
2089 		buf = in_buf;
2090 		pr_aptpl_buf_len = in_pr_aptpl_buf_len;
2091 	}
2092 
2093 	ret = core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
2094 				clear_aptpl_metadata);
2095 	if (ret != 0)
2096 		return ret;
2097 	/*
2098 	 * __core_scsi3_write_aptpl_to_file() will call strlen()
2099 	 * on the passed buf to determine pr_aptpl_buf_len.
2100 	 */
2101 	ret = __core_scsi3_write_aptpl_to_file(dev, buf, 0);
2102 	if (ret != 0)
2103 		return ret;
2104 
2105 	return ret;
2106 }
2107 
2108 static int core_scsi3_emulate_pro_register(
2109 	struct se_cmd *cmd,
2110 	u64 res_key,
2111 	u64 sa_res_key,
2112 	int aptpl,
2113 	int all_tg_pt,
2114 	int spec_i_pt,
2115 	int ignore_key)
2116 {
2117 	struct se_session *se_sess = cmd->se_sess;
2118 	struct se_device *dev = cmd->se_dev;
2119 	struct se_dev_entry *se_deve;
2120 	struct se_lun *se_lun = cmd->se_lun;
2121 	struct se_portal_group *se_tpg;
2122 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp, *pr_reg_e;
2123 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2124 	/* Used for APTPL metadata w/ UNREGISTER */
2125 	unsigned char *pr_aptpl_buf = NULL;
2126 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2127 	int pr_holder = 0, ret = 0, type;
2128 
2129 	if (!se_sess || !se_lun) {
2130 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2131 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2132 		return -EINVAL;
2133 	}
2134 	se_tpg = se_sess->se_tpg;
2135 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2136 
2137 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2138 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2139 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2140 				PR_REG_ISID_LEN);
2141 		isid_ptr = &isid_buf[0];
2142 	}
2143 	/*
2144 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2145 	 */
2146 	pr_reg_e = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2147 	if (!pr_reg_e) {
2148 		if (res_key) {
2149 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2150 				" for SA REGISTER, returning CONFLICT\n");
2151 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2152 			return -EINVAL;
2153 		}
2154 		/*
2155 		 * Do nothing but return GOOD status.
2156 		 */
2157 		if (!sa_res_key)
2158 			return 0;
2159 
2160 		if (!spec_i_pt) {
2161 			/*
2162 			 * Perform the Service Action REGISTER on the Initiator
2163 			 * Port Endpoint that the PRO was received from on the
2164 			 * Logical Unit of the SCSI device server.
2165 			 */
2166 			ret = core_scsi3_alloc_registration(cmd->se_dev,
2167 					se_sess->se_node_acl, se_deve, isid_ptr,
2168 					sa_res_key, all_tg_pt, aptpl,
2169 					ignore_key, 0);
2170 			if (ret != 0) {
2171 				pr_err("Unable to allocate"
2172 					" struct t10_pr_registration\n");
2173 				cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
2174 				return -EINVAL;
2175 			}
2176 		} else {
2177 			/*
2178 			 * Register both the Initiator port that received
2179 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2180 			 * TransportID from Parameter list and loop through
2181 			 * fabric dependent parameter list while calling
2182 			 * logic from of core_scsi3_alloc_registration() for
2183 			 * each TransportID provided SCSI Initiator Port/Device
2184 			 */
2185 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2186 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2187 			if (ret != 0)
2188 				return ret;
2189 		}
2190 		/*
2191 		 * Nothing left to do for the APTPL=0 case.
2192 		 */
2193 		if (!aptpl) {
2194 			pr_tmpl->pr_aptpl_active = 0;
2195 			core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2196 			pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
2197 					" REGISTER\n");
2198 			return 0;
2199 		}
2200 		/*
2201 		 * Locate the newly allocated local I_T Nexus *pr_reg, and
2202 		 * update the APTPL metadata information using its
2203 		 * preallocated *pr_reg->pr_aptpl_buf.
2204 		 */
2205 		pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev,
2206 				se_sess->se_node_acl, se_sess);
2207 
2208 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2209 				&pr_reg->pr_aptpl_buf[0],
2210 				pr_tmpl->pr_aptpl_buf_len);
2211 		if (!ret) {
2212 			pr_tmpl->pr_aptpl_active = 1;
2213 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for REGISTER\n");
2214 		}
2215 
2216 		core_scsi3_put_pr_reg(pr_reg);
2217 		return ret;
2218 	} else {
2219 		/*
2220 		 * Locate the existing *pr_reg via struct se_node_acl pointers
2221 		 */
2222 		pr_reg = pr_reg_e;
2223 		type = pr_reg->pr_res_type;
2224 
2225 		if (!ignore_key) {
2226 			if (res_key != pr_reg->pr_res_key) {
2227 				pr_err("SPC-3 PR REGISTER: Received"
2228 					" res_key: 0x%016Lx does not match"
2229 					" existing SA REGISTER res_key:"
2230 					" 0x%016Lx\n", res_key,
2231 					pr_reg->pr_res_key);
2232 				core_scsi3_put_pr_reg(pr_reg);
2233 				cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2234 				return -EINVAL;
2235 			}
2236 		}
2237 		if (spec_i_pt) {
2238 			pr_err("SPC-3 PR UNREGISTER: SPEC_I_PT"
2239 				" set while sa_res_key=0\n");
2240 			core_scsi3_put_pr_reg(pr_reg);
2241 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
2242 			return -EINVAL;
2243 		}
2244 		/*
2245 		 * An existing ALL_TG_PT=1 registration being released
2246 		 * must also set ALL_TG_PT=1 in the incoming PROUT.
2247 		 */
2248 		if (pr_reg->pr_reg_all_tg_pt && !(all_tg_pt)) {
2249 			pr_err("SPC-3 PR UNREGISTER: ALL_TG_PT=1"
2250 				" registration exists, but ALL_TG_PT=1 bit not"
2251 				" present in received PROUT\n");
2252 			core_scsi3_put_pr_reg(pr_reg);
2253 			cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2254 			return -EINVAL;
2255 		}
2256 		/*
2257 		 * Allocate APTPL metadata buffer used for UNREGISTER ops
2258 		 */
2259 		if (aptpl) {
2260 			pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len,
2261 						GFP_KERNEL);
2262 			if (!pr_aptpl_buf) {
2263 				pr_err("Unable to allocate"
2264 					" pr_aptpl_buf\n");
2265 				core_scsi3_put_pr_reg(pr_reg);
2266 				cmd->scsi_sense_reason =
2267 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2268 				return -EINVAL;
2269 			}
2270 		}
2271 		/*
2272 		 * sa_res_key=0 Unregister Reservation Key for registered I_T
2273 		 * Nexus sa_res_key=1 Change Reservation Key for registered I_T
2274 		 * Nexus.
2275 		 */
2276 		if (!sa_res_key) {
2277 			pr_holder = core_scsi3_check_implict_release(
2278 					cmd->se_dev, pr_reg);
2279 			if (pr_holder < 0) {
2280 				kfree(pr_aptpl_buf);
2281 				core_scsi3_put_pr_reg(pr_reg);
2282 				cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2283 				return -EINVAL;
2284 			}
2285 
2286 			spin_lock(&pr_tmpl->registration_lock);
2287 			/*
2288 			 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2289 			 * and matching pr_res_key.
2290 			 */
2291 			if (pr_reg->pr_reg_all_tg_pt) {
2292 				list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2293 						&pr_tmpl->registration_list,
2294 						pr_reg_list) {
2295 
2296 					if (!pr_reg_p->pr_reg_all_tg_pt)
2297 						continue;
2298 
2299 					if (pr_reg_p->pr_res_key != res_key)
2300 						continue;
2301 
2302 					if (pr_reg == pr_reg_p)
2303 						continue;
2304 
2305 					if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2306 						   pr_reg_p->pr_reg_nacl->initiatorname))
2307 						continue;
2308 
2309 					__core_scsi3_free_registration(dev,
2310 							pr_reg_p, NULL, 0);
2311 				}
2312 			}
2313 			/*
2314 			 * Release the calling I_T Nexus registration now..
2315 			 */
2316 			__core_scsi3_free_registration(cmd->se_dev, pr_reg,
2317 							NULL, 1);
2318 			/*
2319 			 * From spc4r17, section 5.7.11.3 Unregistering
2320 			 *
2321 			 * If the persistent reservation is a registrants only
2322 			 * type, the device server shall establish a unit
2323 			 * attention condition for the initiator port associated
2324 			 * with every registered I_T nexus except for the I_T
2325 			 * nexus on which the PERSISTENT RESERVE OUT command was
2326 			 * received, with the additional sense code set to
2327 			 * RESERVATIONS RELEASED.
2328 			 */
2329 			if (pr_holder &&
2330 			   ((type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
2331 			    (type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY))) {
2332 				list_for_each_entry(pr_reg_p,
2333 						&pr_tmpl->registration_list,
2334 						pr_reg_list) {
2335 
2336 					core_scsi3_ua_allocate(
2337 						pr_reg_p->pr_reg_nacl,
2338 						pr_reg_p->pr_res_mapped_lun,
2339 						0x2A,
2340 						ASCQ_2AH_RESERVATIONS_RELEASED);
2341 				}
2342 			}
2343 			spin_unlock(&pr_tmpl->registration_lock);
2344 
2345 			if (!aptpl) {
2346 				pr_tmpl->pr_aptpl_active = 0;
2347 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2348 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2349 						" for UNREGISTER\n");
2350 				return 0;
2351 			}
2352 
2353 			ret = core_scsi3_update_and_write_aptpl(dev,
2354 					&pr_aptpl_buf[0],
2355 					pr_tmpl->pr_aptpl_buf_len);
2356 			if (!ret) {
2357 				pr_tmpl->pr_aptpl_active = 1;
2358 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2359 						" for UNREGISTER\n");
2360 			}
2361 
2362 			kfree(pr_aptpl_buf);
2363 			return ret;
2364 		} else {
2365 			/*
2366 			 * Increment PRgeneration counter for struct se_device"
2367 			 * upon a successful REGISTER, see spc4r17 section 6.3.2
2368 			 * READ_KEYS service action.
2369 			 */
2370 			pr_reg->pr_res_generation = core_scsi3_pr_generation(
2371 							cmd->se_dev);
2372 			pr_reg->pr_res_key = sa_res_key;
2373 			pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2374 				" Key for %s to: 0x%016Lx PRgeneration:"
2375 				" 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2376 				(ignore_key) ? "_AND_IGNORE_EXISTING_KEY" : "",
2377 				pr_reg->pr_reg_nacl->initiatorname,
2378 				pr_reg->pr_res_key, pr_reg->pr_res_generation);
2379 
2380 			if (!aptpl) {
2381 				pr_tmpl->pr_aptpl_active = 0;
2382 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2383 				core_scsi3_put_pr_reg(pr_reg);
2384 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2385 						" for REGISTER\n");
2386 				return 0;
2387 			}
2388 
2389 			ret = core_scsi3_update_and_write_aptpl(dev,
2390 					&pr_aptpl_buf[0],
2391 					pr_tmpl->pr_aptpl_buf_len);
2392 			if (!ret) {
2393 				pr_tmpl->pr_aptpl_active = 1;
2394 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2395 						" for REGISTER\n");
2396 			}
2397 
2398 			kfree(pr_aptpl_buf);
2399 			core_scsi3_put_pr_reg(pr_reg);
2400 		}
2401 	}
2402 	return 0;
2403 }
2404 
2405 unsigned char *core_scsi3_pr_dump_type(int type)
2406 {
2407 	switch (type) {
2408 	case PR_TYPE_WRITE_EXCLUSIVE:
2409 		return "Write Exclusive Access";
2410 	case PR_TYPE_EXCLUSIVE_ACCESS:
2411 		return "Exclusive Access";
2412 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2413 		return "Write Exclusive Access, Registrants Only";
2414 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2415 		return "Exclusive Access, Registrants Only";
2416 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2417 		return "Write Exclusive Access, All Registrants";
2418 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2419 		return "Exclusive Access, All Registrants";
2420 	default:
2421 		break;
2422 	}
2423 
2424 	return "Unknown SPC-3 PR Type";
2425 }
2426 
2427 static int core_scsi3_pro_reserve(
2428 	struct se_cmd *cmd,
2429 	struct se_device *dev,
2430 	int type,
2431 	int scope,
2432 	u64 res_key)
2433 {
2434 	struct se_session *se_sess = cmd->se_sess;
2435 	struct se_lun *se_lun = cmd->se_lun;
2436 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2437 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2438 	char i_buf[PR_REG_ISID_ID_LEN];
2439 	int ret, prf_isid;
2440 
2441 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2442 
2443 	if (!se_sess || !se_lun) {
2444 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2445 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2446 		return -EINVAL;
2447 	}
2448 	/*
2449 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2450 	 */
2451 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2452 				se_sess);
2453 	if (!pr_reg) {
2454 		pr_err("SPC-3 PR: Unable to locate"
2455 			" PR_REGISTERED *pr_reg for RESERVE\n");
2456 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2457 		return -EINVAL;
2458 	}
2459 	/*
2460 	 * From spc4r17 Section 5.7.9: Reserving:
2461 	 *
2462 	 * An application client creates a persistent reservation by issuing
2463 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2464 	 * a registered I_T nexus with the following parameters:
2465 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2466 	 * 	 registered with the logical unit for the I_T nexus; and
2467 	 */
2468 	if (res_key != pr_reg->pr_res_key) {
2469 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2470 			" does not match existing SA REGISTER res_key:"
2471 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2472 		core_scsi3_put_pr_reg(pr_reg);
2473 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2474 		return -EINVAL;
2475 	}
2476 	/*
2477 	 * From spc4r17 Section 5.7.9: Reserving:
2478 	 *
2479 	 * From above:
2480 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2481 	 *     being created.
2482 	 *
2483 	 * Only one persistent reservation is allowed at a time per logical unit
2484 	 * and that persistent reservation has a scope of LU_SCOPE.
2485 	 */
2486 	if (scope != PR_SCOPE_LU_SCOPE) {
2487 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2488 		core_scsi3_put_pr_reg(pr_reg);
2489 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
2490 		return -EINVAL;
2491 	}
2492 	/*
2493 	 * See if we have an existing PR reservation holder pointer at
2494 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2495 	 * *pr_res_holder.
2496 	 */
2497 	spin_lock(&dev->dev_reservation_lock);
2498 	pr_res_holder = dev->dev_pr_res_holder;
2499 	if (pr_res_holder) {
2500 		/*
2501 		 * From spc4r17 Section 5.7.9: Reserving:
2502 		 *
2503 		 * If the device server receives a PERSISTENT RESERVE OUT
2504 		 * command from an I_T nexus other than a persistent reservation
2505 		 * holder (see 5.7.10) that attempts to create a persistent
2506 		 * reservation when a persistent reservation already exists for
2507 		 * the logical unit, then the command shall be completed with
2508 		 * RESERVATION CONFLICT status.
2509 		 */
2510 		if (pr_res_holder != pr_reg) {
2511 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2512 			pr_err("SPC-3 PR: Attempted RESERVE from"
2513 				" [%s]: %s while reservation already held by"
2514 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2515 				cmd->se_tfo->get_fabric_name(),
2516 				se_sess->se_node_acl->initiatorname,
2517 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2518 				pr_res_holder->pr_reg_nacl->initiatorname);
2519 
2520 			spin_unlock(&dev->dev_reservation_lock);
2521 			core_scsi3_put_pr_reg(pr_reg);
2522 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2523 			return -EINVAL;
2524 		}
2525 		/*
2526 		 * From spc4r17 Section 5.7.9: Reserving:
2527 		 *
2528 		 * If a persistent reservation holder attempts to modify the
2529 		 * type or scope of an existing persistent reservation, the
2530 		 * command shall be completed with RESERVATION CONFLICT status.
2531 		 */
2532 		if ((pr_res_holder->pr_res_type != type) ||
2533 		    (pr_res_holder->pr_res_scope != scope)) {
2534 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2535 			pr_err("SPC-3 PR: Attempted RESERVE from"
2536 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2537 				" while reservation already held by [%s]: %s,"
2538 				" returning RESERVATION_CONFLICT\n",
2539 				cmd->se_tfo->get_fabric_name(),
2540 				se_sess->se_node_acl->initiatorname,
2541 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2542 				pr_res_holder->pr_reg_nacl->initiatorname);
2543 
2544 			spin_unlock(&dev->dev_reservation_lock);
2545 			core_scsi3_put_pr_reg(pr_reg);
2546 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2547 			return -EINVAL;
2548 		}
2549 		/*
2550 		 * From spc4r17 Section 5.7.9: Reserving:
2551 		 *
2552 		 * If the device server receives a PERSISTENT RESERVE OUT
2553 		 * command with RESERVE service action where the TYPE field and
2554 		 * the SCOPE field contain the same values as the existing type
2555 		 * and scope from a persistent reservation holder, it shall not
2556 		 * make any change to the existing persistent reservation and
2557 		 * shall completethe command with GOOD status.
2558 		 */
2559 		spin_unlock(&dev->dev_reservation_lock);
2560 		core_scsi3_put_pr_reg(pr_reg);
2561 		return 0;
2562 	}
2563 	/*
2564 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2565 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2566 	 */
2567 	pr_reg->pr_res_scope = scope;
2568 	pr_reg->pr_res_type = type;
2569 	pr_reg->pr_res_holder = 1;
2570 	dev->dev_pr_res_holder = pr_reg;
2571 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2572 				PR_REG_ISID_ID_LEN);
2573 
2574 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2575 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2576 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2577 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2578 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2579 			cmd->se_tfo->get_fabric_name(),
2580 			se_sess->se_node_acl->initiatorname,
2581 			(prf_isid) ? &i_buf[0] : "");
2582 	spin_unlock(&dev->dev_reservation_lock);
2583 
2584 	if (pr_tmpl->pr_aptpl_active) {
2585 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2586 				&pr_reg->pr_aptpl_buf[0],
2587 				pr_tmpl->pr_aptpl_buf_len);
2588 		if (!ret)
2589 			pr_debug("SPC-3 PR: Updated APTPL metadata"
2590 					" for RESERVE\n");
2591 	}
2592 
2593 	core_scsi3_put_pr_reg(pr_reg);
2594 	return 0;
2595 }
2596 
2597 static int core_scsi3_emulate_pro_reserve(
2598 	struct se_cmd *cmd,
2599 	int type,
2600 	int scope,
2601 	u64 res_key)
2602 {
2603 	struct se_device *dev = cmd->se_dev;
2604 	int ret = 0;
2605 
2606 	switch (type) {
2607 	case PR_TYPE_WRITE_EXCLUSIVE:
2608 	case PR_TYPE_EXCLUSIVE_ACCESS:
2609 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2610 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2611 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2612 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2613 		ret = core_scsi3_pro_reserve(cmd, dev, type, scope, res_key);
2614 		break;
2615 	default:
2616 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2617 			" 0x%02x\n", type);
2618 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2619 		return -EINVAL;
2620 	}
2621 
2622 	return ret;
2623 }
2624 
2625 /*
2626  * Called with struct se_device->dev_reservation_lock held.
2627  */
2628 static void __core_scsi3_complete_pro_release(
2629 	struct se_device *dev,
2630 	struct se_node_acl *se_nacl,
2631 	struct t10_pr_registration *pr_reg,
2632 	int explict)
2633 {
2634 	struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2635 	char i_buf[PR_REG_ISID_ID_LEN];
2636 	int prf_isid;
2637 
2638 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2639 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2640 				PR_REG_ISID_ID_LEN);
2641 	/*
2642 	 * Go ahead and release the current PR reservation holder.
2643 	 */
2644 	dev->dev_pr_res_holder = NULL;
2645 
2646 	pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2647 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2648 		tfo->get_fabric_name(), (explict) ? "explict" : "implict",
2649 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
2650 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2651 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2652 		tfo->get_fabric_name(), se_nacl->initiatorname,
2653 		(prf_isid) ? &i_buf[0] : "");
2654 	/*
2655 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2656 	 */
2657 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2658 }
2659 
2660 static int core_scsi3_emulate_pro_release(
2661 	struct se_cmd *cmd,
2662 	int type,
2663 	int scope,
2664 	u64 res_key)
2665 {
2666 	struct se_device *dev = cmd->se_dev;
2667 	struct se_session *se_sess = cmd->se_sess;
2668 	struct se_lun *se_lun = cmd->se_lun;
2669 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2670 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2671 	int ret, all_reg = 0;
2672 
2673 	if (!se_sess || !se_lun) {
2674 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2675 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2676 		return -EINVAL;
2677 	}
2678 	/*
2679 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2680 	 */
2681 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2682 	if (!pr_reg) {
2683 		pr_err("SPC-3 PR: Unable to locate"
2684 			" PR_REGISTERED *pr_reg for RELEASE\n");
2685 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2686 		return -EINVAL;
2687 	}
2688 	/*
2689 	 * From spc4r17 Section 5.7.11.2 Releasing:
2690 	 *
2691 	 * If there is no persistent reservation or in response to a persistent
2692 	 * reservation release request from a registered I_T nexus that is not a
2693 	 * persistent reservation holder (see 5.7.10), the device server shall
2694 	 * do the following:
2695 	 *
2696 	 *     a) Not release the persistent reservation, if any;
2697 	 *     b) Not remove any registrations; and
2698 	 *     c) Complete the command with GOOD status.
2699 	 */
2700 	spin_lock(&dev->dev_reservation_lock);
2701 	pr_res_holder = dev->dev_pr_res_holder;
2702 	if (!pr_res_holder) {
2703 		/*
2704 		 * No persistent reservation, return GOOD status.
2705 		 */
2706 		spin_unlock(&dev->dev_reservation_lock);
2707 		core_scsi3_put_pr_reg(pr_reg);
2708 		return 0;
2709 	}
2710 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2711 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
2712 		all_reg = 1;
2713 
2714 	if ((all_reg == 0) && (pr_res_holder != pr_reg)) {
2715 		/*
2716 		 * Non 'All Registrants' PR Type cases..
2717 		 * Release request from a registered I_T nexus that is not a
2718 		 * persistent reservation holder. return GOOD status.
2719 		 */
2720 		spin_unlock(&dev->dev_reservation_lock);
2721 		core_scsi3_put_pr_reg(pr_reg);
2722 		return 0;
2723 	}
2724 	/*
2725 	 * From spc4r17 Section 5.7.11.2 Releasing:
2726 	 *
2727 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2728 	 * release a persistent reservation.
2729 	 *
2730 	 * An application client releases the persistent reservation by issuing
2731 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2732 	 * an I_T nexus that is a persistent reservation holder with the
2733 	 * following parameters:
2734 	 *
2735 	 *     a) RESERVATION KEY field set to the value of the reservation key
2736 	 *	  that is registered with the logical unit for the I_T nexus;
2737 	 */
2738 	if (res_key != pr_reg->pr_res_key) {
2739 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2740 			" does not match existing SA REGISTER res_key:"
2741 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2742 		spin_unlock(&dev->dev_reservation_lock);
2743 		core_scsi3_put_pr_reg(pr_reg);
2744 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2745 		return -EINVAL;
2746 	}
2747 	/*
2748 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2749 	 *
2750 	 * b) TYPE field and SCOPE field set to match the persistent
2751 	 *    reservation being released.
2752 	 */
2753 	if ((pr_res_holder->pr_res_type != type) ||
2754 	    (pr_res_holder->pr_res_scope != scope)) {
2755 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2756 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2757 			" reservation from [%s]: %s with different TYPE "
2758 			"and/or SCOPE  while reservation already held by"
2759 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2760 			cmd->se_tfo->get_fabric_name(),
2761 			se_sess->se_node_acl->initiatorname,
2762 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2763 			pr_res_holder->pr_reg_nacl->initiatorname);
2764 
2765 		spin_unlock(&dev->dev_reservation_lock);
2766 		core_scsi3_put_pr_reg(pr_reg);
2767 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2768 		return -EINVAL;
2769 	}
2770 	/*
2771 	 * In response to a persistent reservation release request from the
2772 	 * persistent reservation holder the device server shall perform a
2773 	 * release by doing the following as an uninterrupted series of actions:
2774 	 * a) Release the persistent reservation;
2775 	 * b) Not remove any registration(s);
2776 	 * c) If the released persistent reservation is a registrants only type
2777 	 * or all registrants type persistent reservation,
2778 	 *    the device server shall establish a unit attention condition for
2779 	 *    the initiator port associated with every regis-
2780 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2781 	 *    RESERVE OUT command with RELEASE service action was received,
2782 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2783 	 * d) If the persistent reservation is of any other type, the device
2784 	 *    server shall not establish a unit attention condition.
2785 	 */
2786 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2787 			pr_reg, 1);
2788 
2789 	spin_unlock(&dev->dev_reservation_lock);
2790 
2791 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2792 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2793 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2794 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2795 		/*
2796 		 * If no UNIT ATTENTION conditions will be established for
2797 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2798 		 * go ahead and check for APTPL=1 update+write below
2799 		 */
2800 		goto write_aptpl;
2801 	}
2802 
2803 	spin_lock(&pr_tmpl->registration_lock);
2804 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2805 			pr_reg_list) {
2806 		/*
2807 		 * Do not establish a UNIT ATTENTION condition
2808 		 * for the calling I_T Nexus
2809 		 */
2810 		if (pr_reg_p == pr_reg)
2811 			continue;
2812 
2813 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2814 				pr_reg_p->pr_res_mapped_lun,
2815 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2816 	}
2817 	spin_unlock(&pr_tmpl->registration_lock);
2818 
2819 write_aptpl:
2820 	if (pr_tmpl->pr_aptpl_active) {
2821 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2822 				&pr_reg->pr_aptpl_buf[0],
2823 				pr_tmpl->pr_aptpl_buf_len);
2824 		if (!ret)
2825 			pr_debug("SPC-3 PR: Updated APTPL metadata for RELEASE\n");
2826 	}
2827 
2828 	core_scsi3_put_pr_reg(pr_reg);
2829 	return 0;
2830 }
2831 
2832 static int core_scsi3_emulate_pro_clear(
2833 	struct se_cmd *cmd,
2834 	u64 res_key)
2835 {
2836 	struct se_device *dev = cmd->se_dev;
2837 	struct se_node_acl *pr_reg_nacl;
2838 	struct se_session *se_sess = cmd->se_sess;
2839 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2840 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2841 	u32 pr_res_mapped_lun = 0;
2842 	int calling_it_nexus = 0;
2843 	/*
2844 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2845 	 */
2846 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2847 			se_sess->se_node_acl, se_sess);
2848 	if (!pr_reg_n) {
2849 		pr_err("SPC-3 PR: Unable to locate"
2850 			" PR_REGISTERED *pr_reg for CLEAR\n");
2851 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2852 		return -EINVAL;
2853 	}
2854 	/*
2855 	 * From spc4r17 section 5.7.11.6, Clearing:
2856 	 *
2857 	 * Any application client may release the persistent reservation and
2858 	 * remove all registrations from a device server by issuing a
2859 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2860 	 * registered I_T nexus with the following parameter:
2861 	 *
2862 	 *	a) RESERVATION KEY field set to the value of the reservation key
2863 	 * 	   that is registered with the logical unit for the I_T nexus.
2864 	 */
2865 	if (res_key != pr_reg_n->pr_res_key) {
2866 		pr_err("SPC-3 PR REGISTER: Received"
2867 			" res_key: 0x%016Lx does not match"
2868 			" existing SA REGISTER res_key:"
2869 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2870 		core_scsi3_put_pr_reg(pr_reg_n);
2871 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2872 		return -EINVAL;
2873 	}
2874 	/*
2875 	 * a) Release the persistent reservation, if any;
2876 	 */
2877 	spin_lock(&dev->dev_reservation_lock);
2878 	pr_res_holder = dev->dev_pr_res_holder;
2879 	if (pr_res_holder) {
2880 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2881 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2882 			pr_res_holder, 0);
2883 	}
2884 	spin_unlock(&dev->dev_reservation_lock);
2885 	/*
2886 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2887 	 */
2888 	spin_lock(&pr_tmpl->registration_lock);
2889 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2890 			&pr_tmpl->registration_list, pr_reg_list) {
2891 
2892 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2893 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2894 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2895 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2896 					calling_it_nexus);
2897 		/*
2898 		 * e) Establish a unit attention condition for the initiator
2899 		 *    port associated with every registered I_T nexus other
2900 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2901 		 *    command with CLEAR service action was received, with the
2902 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2903 		 */
2904 		if (!calling_it_nexus)
2905 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2906 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2907 	}
2908 	spin_unlock(&pr_tmpl->registration_lock);
2909 
2910 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2911 		cmd->se_tfo->get_fabric_name());
2912 
2913 	if (pr_tmpl->pr_aptpl_active) {
2914 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2915 		pr_debug("SPC-3 PR: Updated APTPL metadata"
2916 				" for CLEAR\n");
2917 	}
2918 
2919 	core_scsi3_pr_generation(dev);
2920 	return 0;
2921 }
2922 
2923 /*
2924  * Called with struct se_device->dev_reservation_lock held.
2925  */
2926 static void __core_scsi3_complete_pro_preempt(
2927 	struct se_device *dev,
2928 	struct t10_pr_registration *pr_reg,
2929 	struct list_head *preempt_and_abort_list,
2930 	int type,
2931 	int scope,
2932 	int abort)
2933 {
2934 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2935 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2936 	char i_buf[PR_REG_ISID_ID_LEN];
2937 	int prf_isid;
2938 
2939 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2940 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2941 				PR_REG_ISID_ID_LEN);
2942 	/*
2943 	 * Do an implict RELEASE of the existing reservation.
2944 	 */
2945 	if (dev->dev_pr_res_holder)
2946 		__core_scsi3_complete_pro_release(dev, nacl,
2947 				dev->dev_pr_res_holder, 0);
2948 
2949 	dev->dev_pr_res_holder = pr_reg;
2950 	pr_reg->pr_res_holder = 1;
2951 	pr_reg->pr_res_type = type;
2952 	pr_reg->pr_res_scope = scope;
2953 
2954 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2955 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2956 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2957 		core_scsi3_pr_dump_type(type),
2958 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2959 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2960 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2961 		nacl->initiatorname, (prf_isid) ? &i_buf[0] : "");
2962 	/*
2963 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2964 	 * struct t10_pr_registration to the list that will be compared
2965 	 * against received CDBs..
2966 	 */
2967 	if (preempt_and_abort_list)
2968 		list_add_tail(&pr_reg->pr_reg_abort_list,
2969 				preempt_and_abort_list);
2970 }
2971 
2972 static void core_scsi3_release_preempt_and_abort(
2973 	struct list_head *preempt_and_abort_list,
2974 	struct t10_pr_registration *pr_reg_holder)
2975 {
2976 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2977 
2978 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2979 				pr_reg_abort_list) {
2980 
2981 		list_del(&pr_reg->pr_reg_abort_list);
2982 		if (pr_reg_holder == pr_reg)
2983 			continue;
2984 		if (pr_reg->pr_res_holder) {
2985 			pr_warn("pr_reg->pr_res_holder still set\n");
2986 			continue;
2987 		}
2988 
2989 		pr_reg->pr_reg_deve = NULL;
2990 		pr_reg->pr_reg_nacl = NULL;
2991 		kfree(pr_reg->pr_aptpl_buf);
2992 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2993 	}
2994 }
2995 
2996 static int core_scsi3_pro_preempt(
2997 	struct se_cmd *cmd,
2998 	int type,
2999 	int scope,
3000 	u64 res_key,
3001 	u64 sa_res_key,
3002 	int abort)
3003 {
3004 	struct se_device *dev = cmd->se_dev;
3005 	struct se_node_acl *pr_reg_nacl;
3006 	struct se_session *se_sess = cmd->se_sess;
3007 	LIST_HEAD(preempt_and_abort_list);
3008 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
3009 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3010 	u32 pr_res_mapped_lun = 0;
3011 	int all_reg = 0, calling_it_nexus = 0, released_regs = 0;
3012 	int prh_type = 0, prh_scope = 0, ret;
3013 
3014 	if (!se_sess) {
3015 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3016 		return -EINVAL;
3017 	}
3018 
3019 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3020 				se_sess);
3021 	if (!pr_reg_n) {
3022 		pr_err("SPC-3 PR: Unable to locate"
3023 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
3024 			(abort) ? "_AND_ABORT" : "");
3025 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3026 		return -EINVAL;
3027 	}
3028 	if (pr_reg_n->pr_res_key != res_key) {
3029 		core_scsi3_put_pr_reg(pr_reg_n);
3030 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3031 		return -EINVAL;
3032 	}
3033 	if (scope != PR_SCOPE_LU_SCOPE) {
3034 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
3035 		core_scsi3_put_pr_reg(pr_reg_n);
3036 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3037 		return -EINVAL;
3038 	}
3039 
3040 	spin_lock(&dev->dev_reservation_lock);
3041 	pr_res_holder = dev->dev_pr_res_holder;
3042 	if (pr_res_holder &&
3043 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3044 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
3045 		all_reg = 1;
3046 
3047 	if (!all_reg && !sa_res_key) {
3048 		spin_unlock(&dev->dev_reservation_lock);
3049 		core_scsi3_put_pr_reg(pr_reg_n);
3050 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3051 		return -EINVAL;
3052 	}
3053 	/*
3054 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
3055 	 *
3056 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
3057 	 * persistent reservation holder or there is no persistent reservation
3058 	 * holder (i.e., there is no persistent reservation), then the device
3059 	 * server shall perform a preempt by doing the following in an
3060 	 * uninterrupted series of actions. (See below..)
3061 	 */
3062 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
3063 		/*
3064 		 * No existing or SA Reservation Key matching reservations..
3065 		 *
3066 		 * PROUT SA PREEMPT with All Registrant type reservations are
3067 		 * allowed to be processed without a matching SA Reservation Key
3068 		 */
3069 		spin_lock(&pr_tmpl->registration_lock);
3070 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3071 				&pr_tmpl->registration_list, pr_reg_list) {
3072 			/*
3073 			 * Removing of registrations in non all registrants
3074 			 * type reservations without a matching SA reservation
3075 			 * key.
3076 			 *
3077 			 * a) Remove the registrations for all I_T nexuses
3078 			 *    specified by the SERVICE ACTION RESERVATION KEY
3079 			 *    field;
3080 			 * b) Ignore the contents of the SCOPE and TYPE fields;
3081 			 * c) Process tasks as defined in 5.7.1; and
3082 			 * d) Establish a unit attention condition for the
3083 			 *    initiator port associated with every I_T nexus
3084 			 *    that lost its registration other than the I_T
3085 			 *    nexus on which the PERSISTENT RESERVE OUT command
3086 			 *    was received, with the additional sense code set
3087 			 *    to REGISTRATIONS PREEMPTED.
3088 			 */
3089 			if (!all_reg) {
3090 				if (pr_reg->pr_res_key != sa_res_key)
3091 					continue;
3092 
3093 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3094 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3095 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3096 				__core_scsi3_free_registration(dev, pr_reg,
3097 					(abort) ? &preempt_and_abort_list :
3098 						NULL, calling_it_nexus);
3099 				released_regs++;
3100 			} else {
3101 				/*
3102 				 * Case for any existing all registrants type
3103 				 * reservation, follow logic in spc4r17 section
3104 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
3105 				 *
3106 				 * For a ZERO SA Reservation key, release
3107 				 * all other registrations and do an implict
3108 				 * release of active persistent reservation.
3109 				 *
3110 				 * For a non-ZERO SA Reservation key, only
3111 				 * release the matching reservation key from
3112 				 * registrations.
3113 				 */
3114 				if ((sa_res_key) &&
3115 				     (pr_reg->pr_res_key != sa_res_key))
3116 					continue;
3117 
3118 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3119 				if (calling_it_nexus)
3120 					continue;
3121 
3122 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3123 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3124 				__core_scsi3_free_registration(dev, pr_reg,
3125 					(abort) ? &preempt_and_abort_list :
3126 						NULL, 0);
3127 				released_regs++;
3128 			}
3129 			if (!calling_it_nexus)
3130 				core_scsi3_ua_allocate(pr_reg_nacl,
3131 					pr_res_mapped_lun, 0x2A,
3132 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3133 		}
3134 		spin_unlock(&pr_tmpl->registration_lock);
3135 		/*
3136 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
3137 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
3138 		 * RESERVATION KEY field to a value that does not match any
3139 		 * registered reservation key, then the device server shall
3140 		 * complete the command with RESERVATION CONFLICT status.
3141 		 */
3142 		if (!released_regs) {
3143 			spin_unlock(&dev->dev_reservation_lock);
3144 			core_scsi3_put_pr_reg(pr_reg_n);
3145 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3146 			return -EINVAL;
3147 		}
3148 		/*
3149 		 * For an existing all registrants type reservation
3150 		 * with a zero SA rservation key, preempt the existing
3151 		 * reservation with the new PR type and scope.
3152 		 */
3153 		if (pr_res_holder && all_reg && !(sa_res_key)) {
3154 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3155 				(abort) ? &preempt_and_abort_list : NULL,
3156 				type, scope, abort);
3157 
3158 			if (abort)
3159 				core_scsi3_release_preempt_and_abort(
3160 					&preempt_and_abort_list, pr_reg_n);
3161 		}
3162 		spin_unlock(&dev->dev_reservation_lock);
3163 
3164 		if (pr_tmpl->pr_aptpl_active) {
3165 			ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3166 					&pr_reg_n->pr_aptpl_buf[0],
3167 					pr_tmpl->pr_aptpl_buf_len);
3168 			if (!ret)
3169 				pr_debug("SPC-3 PR: Updated APTPL"
3170 					" metadata for  PREEMPT%s\n", (abort) ?
3171 					"_AND_ABORT" : "");
3172 		}
3173 
3174 		core_scsi3_put_pr_reg(pr_reg_n);
3175 		core_scsi3_pr_generation(cmd->se_dev);
3176 		return 0;
3177 	}
3178 	/*
3179 	 * The PREEMPTing SA reservation key matches that of the
3180 	 * existing persistent reservation, first, we check if
3181 	 * we are preempting our own reservation.
3182 	 * From spc4r17, section 5.7.11.4.3 Preempting
3183 	 * persistent reservations and registration handling
3184 	 *
3185 	 * If an all registrants persistent reservation is not
3186 	 * present, it is not an error for the persistent
3187 	 * reservation holder to preempt itself (i.e., a
3188 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3189 	 * or a PREEMPT AND ABORT service action with the
3190 	 * SERVICE ACTION RESERVATION KEY value equal to the
3191 	 * persistent reservation holder's reservation key that
3192 	 * is received from the persistent reservation holder).
3193 	 * In that case, the device server shall establish the
3194 	 * new persistent reservation and maintain the
3195 	 * registration.
3196 	 */
3197 	prh_type = pr_res_holder->pr_res_type;
3198 	prh_scope = pr_res_holder->pr_res_scope;
3199 	/*
3200 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3201 	 * persistent reservation holder (see 5.7.10), the device
3202 	 * server shall perform a preempt by doing the following as
3203 	 * an uninterrupted series of actions:
3204 	 *
3205 	 * a) Release the persistent reservation for the holder
3206 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3207 	 */
3208 	if (pr_reg_n != pr_res_holder)
3209 		__core_scsi3_complete_pro_release(dev,
3210 				pr_res_holder->pr_reg_nacl,
3211 				dev->dev_pr_res_holder, 0);
3212 	/*
3213 	 * b) Remove the registrations for all I_T nexuses identified
3214 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3215 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3216 	 *    OUT command. If an all registrants persistent reservation
3217 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3218 	 *    is set to zero, then all registrations shall be removed
3219 	 *    except for that of the I_T nexus that is being used for
3220 	 *    the PERSISTENT RESERVE OUT command;
3221 	 */
3222 	spin_lock(&pr_tmpl->registration_lock);
3223 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3224 			&pr_tmpl->registration_list, pr_reg_list) {
3225 
3226 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3227 		if (calling_it_nexus)
3228 			continue;
3229 
3230 		if (pr_reg->pr_res_key != sa_res_key)
3231 			continue;
3232 
3233 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3234 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3235 		__core_scsi3_free_registration(dev, pr_reg,
3236 				(abort) ? &preempt_and_abort_list : NULL,
3237 				calling_it_nexus);
3238 		/*
3239 		 * e) Establish a unit attention condition for the initiator
3240 		 *    port associated with every I_T nexus that lost its
3241 		 *    persistent reservation and/or registration, with the
3242 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3243 		 */
3244 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3245 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3246 	}
3247 	spin_unlock(&pr_tmpl->registration_lock);
3248 	/*
3249 	 * c) Establish a persistent reservation for the preempting
3250 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3251 	 */
3252 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3253 			(abort) ? &preempt_and_abort_list : NULL,
3254 			type, scope, abort);
3255 	/*
3256 	 * d) Process tasks as defined in 5.7.1;
3257 	 * e) See above..
3258 	 * f) If the type or scope has changed, then for every I_T nexus
3259 	 *    whose reservation key was not removed, except for the I_T
3260 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3261 	 *    received, the device server shall establish a unit
3262 	 *    attention condition for the initiator port associated with
3263 	 *    that I_T nexus, with the additional sense code set to
3264 	 *    RESERVATIONS RELEASED. If the type or scope have not
3265 	 *    changed, then no unit attention condition(s) shall be
3266 	 *    established for this reason.
3267 	 */
3268 	if ((prh_type != type) || (prh_scope != scope)) {
3269 		spin_lock(&pr_tmpl->registration_lock);
3270 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3271 				&pr_tmpl->registration_list, pr_reg_list) {
3272 
3273 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3274 			if (calling_it_nexus)
3275 				continue;
3276 
3277 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
3278 					pr_reg->pr_res_mapped_lun, 0x2A,
3279 					ASCQ_2AH_RESERVATIONS_RELEASED);
3280 		}
3281 		spin_unlock(&pr_tmpl->registration_lock);
3282 	}
3283 	spin_unlock(&dev->dev_reservation_lock);
3284 	/*
3285 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3286 	 * All received CDBs for the matching existing reservation and
3287 	 * registrations undergo ABORT_TASK logic.
3288 	 *
3289 	 * From there, core_scsi3_release_preempt_and_abort() will
3290 	 * release every registration in the list (which have already
3291 	 * been removed from the primary pr_reg list), except the
3292 	 * new persistent reservation holder, the calling Initiator Port.
3293 	 */
3294 	if (abort) {
3295 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3296 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3297 						pr_reg_n);
3298 	}
3299 
3300 	if (pr_tmpl->pr_aptpl_active) {
3301 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3302 				&pr_reg_n->pr_aptpl_buf[0],
3303 				pr_tmpl->pr_aptpl_buf_len);
3304 		if (!ret)
3305 			pr_debug("SPC-3 PR: Updated APTPL metadata for PREEMPT"
3306 				"%s\n", (abort) ? "_AND_ABORT" : "");
3307 	}
3308 
3309 	core_scsi3_put_pr_reg(pr_reg_n);
3310 	core_scsi3_pr_generation(cmd->se_dev);
3311 	return 0;
3312 }
3313 
3314 static int core_scsi3_emulate_pro_preempt(
3315 	struct se_cmd *cmd,
3316 	int type,
3317 	int scope,
3318 	u64 res_key,
3319 	u64 sa_res_key,
3320 	int abort)
3321 {
3322 	int ret = 0;
3323 
3324 	switch (type) {
3325 	case PR_TYPE_WRITE_EXCLUSIVE:
3326 	case PR_TYPE_EXCLUSIVE_ACCESS:
3327 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3328 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3329 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3330 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3331 		ret = core_scsi3_pro_preempt(cmd, type, scope,
3332 				res_key, sa_res_key, abort);
3333 		break;
3334 	default:
3335 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3336 			" Type: 0x%02x\n", (abort) ? "_AND_ABORT" : "", type);
3337 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3338 		return -EINVAL;
3339 	}
3340 
3341 	return ret;
3342 }
3343 
3344 
3345 static int core_scsi3_emulate_pro_register_and_move(
3346 	struct se_cmd *cmd,
3347 	u64 res_key,
3348 	u64 sa_res_key,
3349 	int aptpl,
3350 	int unreg)
3351 {
3352 	struct se_session *se_sess = cmd->se_sess;
3353 	struct se_device *dev = cmd->se_dev;
3354 	struct se_dev_entry *dest_se_deve = NULL;
3355 	struct se_lun *se_lun = cmd->se_lun;
3356 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3357 	struct se_port *se_port;
3358 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3359 	struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3360 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3361 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3362 	unsigned char *buf;
3363 	unsigned char *initiator_str;
3364 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
3365 	u32 tid_len, tmp_tid_len;
3366 	int new_reg = 0, type, scope, ret, matching_iname, prf_isid;
3367 	unsigned short rtpi;
3368 	unsigned char proto_ident;
3369 
3370 	if (!se_sess || !se_lun) {
3371 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3372 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3373 		return -EINVAL;
3374 	}
3375 	memset(dest_iport, 0, 64);
3376 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3377 	se_tpg = se_sess->se_tpg;
3378 	tf_ops = se_tpg->se_tpg_tfo;
3379 	/*
3380 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3381 	 *	Register behaviors for a REGISTER AND MOVE service action
3382 	 *
3383 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3384 	 */
3385 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3386 				se_sess);
3387 	if (!pr_reg) {
3388 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3389 			" *pr_reg for REGISTER_AND_MOVE\n");
3390 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3391 		return -EINVAL;
3392 	}
3393 	/*
3394 	 * The provided reservation key much match the existing reservation key
3395 	 * provided during this initiator's I_T nexus registration.
3396 	 */
3397 	if (res_key != pr_reg->pr_res_key) {
3398 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3399 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3400 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3401 		core_scsi3_put_pr_reg(pr_reg);
3402 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3403 		return -EINVAL;
3404 	}
3405 	/*
3406 	 * The service active reservation key needs to be non zero
3407 	 */
3408 	if (!sa_res_key) {
3409 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3410 			" sa_res_key\n");
3411 		core_scsi3_put_pr_reg(pr_reg);
3412 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3413 		return -EINVAL;
3414 	}
3415 
3416 	/*
3417 	 * Determine the Relative Target Port Identifier where the reservation
3418 	 * will be moved to for the TransportID containing SCSI initiator WWN
3419 	 * information.
3420 	 */
3421 	buf = transport_kmap_data_sg(cmd);
3422 	rtpi = (buf[18] & 0xff) << 8;
3423 	rtpi |= buf[19] & 0xff;
3424 	tid_len = (buf[20] & 0xff) << 24;
3425 	tid_len |= (buf[21] & 0xff) << 16;
3426 	tid_len |= (buf[22] & 0xff) << 8;
3427 	tid_len |= buf[23] & 0xff;
3428 	transport_kunmap_data_sg(cmd);
3429 	buf = NULL;
3430 
3431 	if ((tid_len + 24) != cmd->data_length) {
3432 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3433 			" does not equal CDB data_length: %u\n", tid_len,
3434 			cmd->data_length);
3435 		core_scsi3_put_pr_reg(pr_reg);
3436 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3437 		return -EINVAL;
3438 	}
3439 
3440 	spin_lock(&dev->se_port_lock);
3441 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3442 		if (se_port->sep_rtpi != rtpi)
3443 			continue;
3444 		dest_se_tpg = se_port->sep_tpg;
3445 		if (!dest_se_tpg)
3446 			continue;
3447 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3448 		if (!dest_tf_ops)
3449 			continue;
3450 
3451 		atomic_inc(&dest_se_tpg->tpg_pr_ref_count);
3452 		smp_mb__after_atomic_inc();
3453 		spin_unlock(&dev->se_port_lock);
3454 
3455 		ret = core_scsi3_tpg_depend_item(dest_se_tpg);
3456 		if (ret != 0) {
3457 			pr_err("core_scsi3_tpg_depend_item() failed"
3458 				" for dest_se_tpg\n");
3459 			atomic_dec(&dest_se_tpg->tpg_pr_ref_count);
3460 			smp_mb__after_atomic_dec();
3461 			core_scsi3_put_pr_reg(pr_reg);
3462 			cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3463 			return -EINVAL;
3464 		}
3465 
3466 		spin_lock(&dev->se_port_lock);
3467 		break;
3468 	}
3469 	spin_unlock(&dev->se_port_lock);
3470 
3471 	if (!dest_se_tpg || !dest_tf_ops) {
3472 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3473 			" fabric ops from Relative Target Port Identifier:"
3474 			" %hu\n", rtpi);
3475 		core_scsi3_put_pr_reg(pr_reg);
3476 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3477 		return -EINVAL;
3478 	}
3479 
3480 	buf = transport_kmap_data_sg(cmd);
3481 	proto_ident = (buf[24] & 0x0f);
3482 
3483 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3484 			" 0x%02x\n", proto_ident);
3485 
3486 	if (proto_ident != dest_tf_ops->get_fabric_proto_ident(dest_se_tpg)) {
3487 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3488 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3489 			" from fabric: %s\n", proto_ident,
3490 			dest_tf_ops->get_fabric_proto_ident(dest_se_tpg),
3491 			dest_tf_ops->get_fabric_name());
3492 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3493 		ret = -EINVAL;
3494 		goto out;
3495 	}
3496 	if (dest_tf_ops->tpg_parse_pr_out_transport_id == NULL) {
3497 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Fabric does not"
3498 			" containg a valid tpg_parse_pr_out_transport_id"
3499 			" function pointer\n");
3500 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3501 		ret = -EINVAL;
3502 		goto out;
3503 	}
3504 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(dest_se_tpg,
3505 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3506 	if (!initiator_str) {
3507 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3508 			" initiator_str from Transport ID\n");
3509 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3510 		ret = -EINVAL;
3511 		goto out;
3512 	}
3513 
3514 	transport_kunmap_data_sg(cmd);
3515 	buf = NULL;
3516 
3517 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3518 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3519 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3520 		iport_ptr : "");
3521 	/*
3522 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3523 	 * action specifies a TransportID that is the same as the initiator port
3524 	 * of the I_T nexus for the command received, then the command shall
3525 	 * be terminated with CHECK CONDITION status, with the sense key set to
3526 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3527 	 * IN PARAMETER LIST.
3528 	 */
3529 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3530 	matching_iname = (!strcmp(initiator_str,
3531 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3532 	if (!matching_iname)
3533 		goto after_iport_check;
3534 
3535 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3536 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3537 			" matches: %s on received I_T Nexus\n", initiator_str,
3538 			pr_reg_nacl->initiatorname);
3539 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3540 		ret = -EINVAL;
3541 		goto out;
3542 	}
3543 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3544 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3545 			" matches: %s %s on received I_T Nexus\n",
3546 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3547 			pr_reg->pr_reg_isid);
3548 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3549 		ret = -EINVAL;
3550 		goto out;
3551 	}
3552 after_iport_check:
3553 	/*
3554 	 * Locate the destination struct se_node_acl from the received Transport ID
3555 	 */
3556 	spin_lock_irq(&dest_se_tpg->acl_node_lock);
3557 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3558 				initiator_str);
3559 	if (dest_node_acl) {
3560 		atomic_inc(&dest_node_acl->acl_pr_ref_count);
3561 		smp_mb__after_atomic_inc();
3562 	}
3563 	spin_unlock_irq(&dest_se_tpg->acl_node_lock);
3564 
3565 	if (!dest_node_acl) {
3566 		pr_err("Unable to locate %s dest_node_acl for"
3567 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3568 			initiator_str);
3569 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3570 		ret = -EINVAL;
3571 		goto out;
3572 	}
3573 	ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
3574 	if (ret != 0) {
3575 		pr_err("core_scsi3_nodeacl_depend_item() for"
3576 			" dest_node_acl\n");
3577 		atomic_dec(&dest_node_acl->acl_pr_ref_count);
3578 		smp_mb__after_atomic_dec();
3579 		dest_node_acl = NULL;
3580 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3581 		ret = -EINVAL;
3582 		goto out;
3583 	}
3584 
3585 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3586 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3587 		dest_node_acl->initiatorname);
3588 
3589 	/*
3590 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3591 	 * PORT IDENTIFIER.
3592 	 */
3593 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3594 	if (!dest_se_deve) {
3595 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3596 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3597 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3598 		ret = -EINVAL;
3599 		goto out;
3600 	}
3601 
3602 	ret = core_scsi3_lunacl_depend_item(dest_se_deve);
3603 	if (ret < 0) {
3604 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3605 		atomic_dec(&dest_se_deve->pr_ref_count);
3606 		smp_mb__after_atomic_dec();
3607 		dest_se_deve = NULL;
3608 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3609 		ret = -EINVAL;
3610 		goto out;
3611 	}
3612 
3613 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3614 		" ACL for dest_se_deve->mapped_lun: %u\n",
3615 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3616 		dest_se_deve->mapped_lun);
3617 
3618 	/*
3619 	 * A persistent reservation needs to already existing in order to
3620 	 * successfully complete the REGISTER_AND_MOVE service action..
3621 	 */
3622 	spin_lock(&dev->dev_reservation_lock);
3623 	pr_res_holder = dev->dev_pr_res_holder;
3624 	if (!pr_res_holder) {
3625 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3626 			" currently held\n");
3627 		spin_unlock(&dev->dev_reservation_lock);
3628 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3629 		ret = -EINVAL;
3630 		goto out;
3631 	}
3632 	/*
3633 	 * The received on I_T Nexus must be the reservation holder.
3634 	 *
3635 	 * From spc4r17 section 5.7.8  Table 50 --
3636 	 * 	Register behaviors for a REGISTER AND MOVE service action
3637 	 */
3638 	if (pr_res_holder != pr_reg) {
3639 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3640 			" Nexus is not reservation holder\n");
3641 		spin_unlock(&dev->dev_reservation_lock);
3642 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3643 		ret = -EINVAL;
3644 		goto out;
3645 	}
3646 	/*
3647 	 * From spc4r17 section 5.7.8: registering and moving reservation
3648 	 *
3649 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3650 	 * action is received and the established persistent reservation is a
3651 	 * Write Exclusive - All Registrants type or Exclusive Access -
3652 	 * All Registrants type reservation, then the command shall be completed
3653 	 * with RESERVATION CONFLICT status.
3654 	 */
3655 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3656 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3657 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3658 			" reservation for type: %s\n",
3659 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3660 		spin_unlock(&dev->dev_reservation_lock);
3661 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3662 		ret = -EINVAL;
3663 		goto out;
3664 	}
3665 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3666 	/*
3667 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3668 	 */
3669 	type = pr_res_holder->pr_res_type;
3670 	scope = pr_res_holder->pr_res_type;
3671 	/*
3672 	 * c) Associate the reservation key specified in the SERVICE ACTION
3673 	 *    RESERVATION KEY field with the I_T nexus specified as the
3674 	 *    destination of the register and move, where:
3675 	 *    A) The I_T nexus is specified by the TransportID and the
3676 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3677 	 *    B) Regardless of the TransportID format used, the association for
3678 	 *       the initiator port is based on either the initiator port name
3679 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3680 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3681 	 *       transport protocols where port names are not required;
3682 	 * d) Register the reservation key specified in the SERVICE ACTION
3683 	 *    RESERVATION KEY field;
3684 	 * e) Retain the reservation key specified in the SERVICE ACTION
3685 	 *    RESERVATION KEY field and associated information;
3686 	 *
3687 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3688 	 * register an I_T nexus that is already registered with the same
3689 	 * reservation key or a different reservation key.
3690 	 */
3691 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3692 					iport_ptr);
3693 	if (!dest_pr_reg) {
3694 		ret = core_scsi3_alloc_registration(cmd->se_dev,
3695 				dest_node_acl, dest_se_deve, iport_ptr,
3696 				sa_res_key, 0, aptpl, 2, 1);
3697 		if (ret != 0) {
3698 			spin_unlock(&dev->dev_reservation_lock);
3699 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3700 			ret = -EINVAL;
3701 			goto out;
3702 		}
3703 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3704 						iport_ptr);
3705 		new_reg = 1;
3706 	}
3707 	/*
3708 	 * f) Release the persistent reservation for the persistent reservation
3709 	 *    holder (i.e., the I_T nexus on which the
3710 	 */
3711 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3712 			dev->dev_pr_res_holder, 0);
3713 	/*
3714 	 * g) Move the persistent reservation to the specified I_T nexus using
3715 	 *    the same scope and type as the persistent reservation released in
3716 	 *    item f); and
3717 	 */
3718 	dev->dev_pr_res_holder = dest_pr_reg;
3719 	dest_pr_reg->pr_res_holder = 1;
3720 	dest_pr_reg->pr_res_type = type;
3721 	pr_reg->pr_res_scope = scope;
3722 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
3723 				PR_REG_ISID_ID_LEN);
3724 	/*
3725 	 * Increment PRGeneration for existing registrations..
3726 	 */
3727 	if (!new_reg)
3728 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3729 	spin_unlock(&dev->dev_reservation_lock);
3730 
3731 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3732 		" created new reservation holder TYPE: %s on object RTPI:"
3733 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3734 		core_scsi3_pr_dump_type(type), rtpi,
3735 		dest_pr_reg->pr_res_generation);
3736 	pr_debug("SPC-3 PR Successfully moved reservation from"
3737 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3738 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3739 		(prf_isid) ? &i_buf[0] : "", dest_tf_ops->get_fabric_name(),
3740 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3741 		iport_ptr : "");
3742 	/*
3743 	 * It is now safe to release configfs group dependencies for destination
3744 	 * of Transport ID Initiator Device/Port Identifier
3745 	 */
3746 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3747 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3748 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3749 	/*
3750 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3751 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3752 	 */
3753 	if (unreg) {
3754 		spin_lock(&pr_tmpl->registration_lock);
3755 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3756 		spin_unlock(&pr_tmpl->registration_lock);
3757 	} else
3758 		core_scsi3_put_pr_reg(pr_reg);
3759 
3760 	/*
3761 	 * Clear the APTPL metadata if APTPL has been disabled, otherwise
3762 	 * write out the updated metadata to struct file for this SCSI device.
3763 	 */
3764 	if (!aptpl) {
3765 		pr_tmpl->pr_aptpl_active = 0;
3766 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
3767 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
3768 				" REGISTER_AND_MOVE\n");
3769 	} else {
3770 		pr_tmpl->pr_aptpl_active = 1;
3771 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3772 				&dest_pr_reg->pr_aptpl_buf[0],
3773 				pr_tmpl->pr_aptpl_buf_len);
3774 		if (!ret)
3775 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for"
3776 					" REGISTER_AND_MOVE\n");
3777 	}
3778 
3779 	transport_kunmap_data_sg(cmd);
3780 
3781 	core_scsi3_put_pr_reg(dest_pr_reg);
3782 	return 0;
3783 out:
3784 	if (buf)
3785 		transport_kunmap_data_sg(cmd);
3786 	if (dest_se_deve)
3787 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3788 	if (dest_node_acl)
3789 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3790 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3791 	core_scsi3_put_pr_reg(pr_reg);
3792 	return ret;
3793 }
3794 
3795 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3796 {
3797 	unsigned int __v1, __v2;
3798 
3799 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3800 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3801 
3802 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3803 }
3804 
3805 /*
3806  * See spc4r17 section 6.14 Table 170
3807  */
3808 int target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3809 {
3810 	unsigned char *cdb = &cmd->t_task_cdb[0];
3811 	unsigned char *buf;
3812 	u64 res_key, sa_res_key;
3813 	int sa, scope, type, aptpl;
3814 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3815 	int ret;
3816 
3817 	/*
3818 	 * Following spc2r20 5.5.1 Reservations overview:
3819 	 *
3820 	 * If a logical unit has been reserved by any RESERVE command and is
3821 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3822 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3823 	 * initiator or service action and shall terminate with a RESERVATION
3824 	 * CONFLICT status.
3825 	 */
3826 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS) {
3827 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3828 			" SPC-2 reservation is held, returning"
3829 			" RESERVATION_CONFLICT\n");
3830 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3831 		ret = -EINVAL;
3832 		goto out;
3833 	}
3834 
3835 	/*
3836 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3837 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3838 	 */
3839 	if (!cmd->se_sess) {
3840 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3841 		ret = -EINVAL;
3842 		goto out;
3843 	}
3844 
3845 	if (cmd->data_length < 24) {
3846 		pr_warn("SPC-PR: Received PR OUT parameter list"
3847 			" length too small: %u\n", cmd->data_length);
3848 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3849 		ret = -EINVAL;
3850 		goto out;
3851 	}
3852 	/*
3853 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3854 	 */
3855 	sa = (cdb[1] & 0x1f);
3856 	scope = (cdb[2] & 0xf0);
3857 	type = (cdb[2] & 0x0f);
3858 
3859 	buf = transport_kmap_data_sg(cmd);
3860 	/*
3861 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3862 	 */
3863 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3864 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3865 	/*
3866 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3867 	 * SCSI TransportIDs.
3868 	 */
3869 	if (sa != PRO_REGISTER_AND_MOVE) {
3870 		spec_i_pt = (buf[20] & 0x08);
3871 		all_tg_pt = (buf[20] & 0x04);
3872 		aptpl = (buf[20] & 0x01);
3873 	} else {
3874 		aptpl = (buf[17] & 0x01);
3875 		unreg = (buf[17] & 0x02);
3876 	}
3877 	transport_kunmap_data_sg(cmd);
3878 	buf = NULL;
3879 
3880 	/*
3881 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3882 	 */
3883 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER)) {
3884 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3885 		ret = -EINVAL;
3886 		goto out;
3887 	}
3888 
3889 	/*
3890 	 * From spc4r17 section 6.14:
3891 	 *
3892 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3893 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3894 	 * the command shall be terminated with CHECK CONDITION status, with
3895 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3896 	 * code set to PARAMETER LIST LENGTH ERROR.
3897 	 */
3898 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3899 	    (cmd->data_length != 24)) {
3900 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3901 			" list length: %u\n", cmd->data_length);
3902 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3903 		ret = -EINVAL;
3904 		goto out;
3905 	}
3906 	/*
3907 	 * (core_scsi3_emulate_pro_* function parameters
3908 	 * are defined by spc4r17 Table 174:
3909 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3910 	 */
3911 	switch (sa) {
3912 	case PRO_REGISTER:
3913 		ret = core_scsi3_emulate_pro_register(cmd,
3914 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 0);
3915 		break;
3916 	case PRO_RESERVE:
3917 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3918 		break;
3919 	case PRO_RELEASE:
3920 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3921 		break;
3922 	case PRO_CLEAR:
3923 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3924 		break;
3925 	case PRO_PREEMPT:
3926 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3927 					res_key, sa_res_key, 0);
3928 		break;
3929 	case PRO_PREEMPT_AND_ABORT:
3930 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3931 					res_key, sa_res_key, 1);
3932 		break;
3933 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3934 		ret = core_scsi3_emulate_pro_register(cmd,
3935 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 1);
3936 		break;
3937 	case PRO_REGISTER_AND_MOVE:
3938 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3939 				sa_res_key, aptpl, unreg);
3940 		break;
3941 	default:
3942 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3943 			" action: 0x%02x\n", cdb[1] & 0x1f);
3944 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3945 		ret = -EINVAL;
3946 		break;
3947 	}
3948 
3949 out:
3950 	if (!ret)
3951 		target_complete_cmd(cmd, GOOD);
3952 	return ret;
3953 }
3954 
3955 /*
3956  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3957  *
3958  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3959  */
3960 static int core_scsi3_pri_read_keys(struct se_cmd *cmd)
3961 {
3962 	struct se_device *se_dev = cmd->se_dev;
3963 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
3964 	struct t10_pr_registration *pr_reg;
3965 	unsigned char *buf;
3966 	u32 add_len = 0, off = 8;
3967 
3968 	if (cmd->data_length < 8) {
3969 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3970 			" too small\n", cmd->data_length);
3971 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3972 		return -EINVAL;
3973 	}
3974 
3975 	buf = transport_kmap_data_sg(cmd);
3976 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
3977 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
3978 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
3979 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
3980 
3981 	spin_lock(&su_dev->t10_pr.registration_lock);
3982 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
3983 			pr_reg_list) {
3984 		/*
3985 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3986 		 * next reservation key list descriptor.
3987 		 */
3988 		if ((add_len + 8) > (cmd->data_length - 8))
3989 			break;
3990 
3991 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3992 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3993 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3994 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3995 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3996 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3997 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3998 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3999 
4000 		add_len += 8;
4001 	}
4002 	spin_unlock(&su_dev->t10_pr.registration_lock);
4003 
4004 	buf[4] = ((add_len >> 24) & 0xff);
4005 	buf[5] = ((add_len >> 16) & 0xff);
4006 	buf[6] = ((add_len >> 8) & 0xff);
4007 	buf[7] = (add_len & 0xff);
4008 
4009 	transport_kunmap_data_sg(cmd);
4010 
4011 	return 0;
4012 }
4013 
4014 /*
4015  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
4016  *
4017  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
4018  */
4019 static int core_scsi3_pri_read_reservation(struct se_cmd *cmd)
4020 {
4021 	struct se_device *se_dev = cmd->se_dev;
4022 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
4023 	struct t10_pr_registration *pr_reg;
4024 	unsigned char *buf;
4025 	u64 pr_res_key;
4026 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
4027 
4028 	if (cmd->data_length < 8) {
4029 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
4030 			" too small\n", cmd->data_length);
4031 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4032 		return -EINVAL;
4033 	}
4034 
4035 	buf = transport_kmap_data_sg(cmd);
4036 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
4037 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
4038 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
4039 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
4040 
4041 	spin_lock(&se_dev->dev_reservation_lock);
4042 	pr_reg = se_dev->dev_pr_res_holder;
4043 	if (pr_reg) {
4044 		/*
4045 		 * Set the hardcoded Additional Length
4046 		 */
4047 		buf[4] = ((add_len >> 24) & 0xff);
4048 		buf[5] = ((add_len >> 16) & 0xff);
4049 		buf[6] = ((add_len >> 8) & 0xff);
4050 		buf[7] = (add_len & 0xff);
4051 
4052 		if (cmd->data_length < 22)
4053 			goto err;
4054 
4055 		/*
4056 		 * Set the Reservation key.
4057 		 *
4058 		 * From spc4r17, section 5.7.10:
4059 		 * A persistent reservation holder has its reservation key
4060 		 * returned in the parameter data from a PERSISTENT
4061 		 * RESERVE IN command with READ RESERVATION service action as
4062 		 * follows:
4063 		 * a) For a persistent reservation of the type Write Exclusive
4064 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
4065 		 *      the reservation key shall be set to zero; or
4066 		 * b) For all other persistent reservation types, the
4067 		 *    reservation key shall be set to the registered
4068 		 *    reservation key for the I_T nexus that holds the
4069 		 *    persistent reservation.
4070 		 */
4071 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
4072 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
4073 			pr_res_key = 0;
4074 		else
4075 			pr_res_key = pr_reg->pr_res_key;
4076 
4077 		buf[8] = ((pr_res_key >> 56) & 0xff);
4078 		buf[9] = ((pr_res_key >> 48) & 0xff);
4079 		buf[10] = ((pr_res_key >> 40) & 0xff);
4080 		buf[11] = ((pr_res_key >> 32) & 0xff);
4081 		buf[12] = ((pr_res_key >> 24) & 0xff);
4082 		buf[13] = ((pr_res_key >> 16) & 0xff);
4083 		buf[14] = ((pr_res_key >> 8) & 0xff);
4084 		buf[15] = (pr_res_key & 0xff);
4085 		/*
4086 		 * Set the SCOPE and TYPE
4087 		 */
4088 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
4089 			  (pr_reg->pr_res_type & 0x0f);
4090 	}
4091 
4092 err:
4093 	spin_unlock(&se_dev->dev_reservation_lock);
4094 	transport_kunmap_data_sg(cmd);
4095 
4096 	return 0;
4097 }
4098 
4099 /*
4100  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
4101  *
4102  * See spc4r17 section 6.13.4 Table 165
4103  */
4104 static int core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
4105 {
4106 	struct se_device *dev = cmd->se_dev;
4107 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
4108 	unsigned char *buf;
4109 	u16 add_len = 8; /* Hardcoded to 8. */
4110 
4111 	if (cmd->data_length < 6) {
4112 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
4113 			" %u too small\n", cmd->data_length);
4114 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4115 		return -EINVAL;
4116 	}
4117 
4118 	buf = transport_kmap_data_sg(cmd);
4119 
4120 	buf[0] = ((add_len << 8) & 0xff);
4121 	buf[1] = (add_len & 0xff);
4122 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
4123 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
4124 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
4125 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
4126 	/*
4127 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
4128 	 * set the TMV: Task Mask Valid bit.
4129 	 */
4130 	buf[3] |= 0x80;
4131 	/*
4132 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
4133 	 */
4134 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
4135 	/*
4136 	 * PTPL_A: Persistence across Target Power Loss Active bit
4137 	 */
4138 	if (pr_tmpl->pr_aptpl_active)
4139 		buf[3] |= 0x01;
4140 	/*
4141 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
4142 	 */
4143 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4144 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
4145 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
4146 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
4147 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
4148 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4149 
4150 	transport_kunmap_data_sg(cmd);
4151 
4152 	return 0;
4153 }
4154 
4155 /*
4156  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
4157  *
4158  * See spc4r17 section 6.13.5 Table 168 and 169
4159  */
4160 static int core_scsi3_pri_read_full_status(struct se_cmd *cmd)
4161 {
4162 	struct se_device *se_dev = cmd->se_dev;
4163 	struct se_node_acl *se_nacl;
4164 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
4165 	struct se_portal_group *se_tpg;
4166 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
4167 	struct t10_reservation *pr_tmpl = &se_dev->se_sub_dev->t10_pr;
4168 	unsigned char *buf;
4169 	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
4170 	u32 off = 8; /* off into first Full Status descriptor */
4171 	int format_code = 0;
4172 
4173 	if (cmd->data_length < 8) {
4174 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
4175 			" too small\n", cmd->data_length);
4176 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4177 		return -EINVAL;
4178 	}
4179 
4180 	buf = transport_kmap_data_sg(cmd);
4181 
4182 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
4183 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
4184 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
4185 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
4186 
4187 	spin_lock(&pr_tmpl->registration_lock);
4188 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
4189 			&pr_tmpl->registration_list, pr_reg_list) {
4190 
4191 		se_nacl = pr_reg->pr_reg_nacl;
4192 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
4193 		add_desc_len = 0;
4194 
4195 		atomic_inc(&pr_reg->pr_res_holders);
4196 		smp_mb__after_atomic_inc();
4197 		spin_unlock(&pr_tmpl->registration_lock);
4198 		/*
4199 		 * Determine expected length of $FABRIC_MOD specific
4200 		 * TransportID full status descriptor..
4201 		 */
4202 		exp_desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id_len(
4203 				se_tpg, se_nacl, pr_reg, &format_code);
4204 
4205 		if ((exp_desc_len + add_len) > cmd->data_length) {
4206 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
4207 				" out of buffer: %d\n", cmd->data_length);
4208 			spin_lock(&pr_tmpl->registration_lock);
4209 			atomic_dec(&pr_reg->pr_res_holders);
4210 			smp_mb__after_atomic_dec();
4211 			break;
4212 		}
4213 		/*
4214 		 * Set RESERVATION KEY
4215 		 */
4216 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
4217 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
4218 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
4219 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
4220 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
4221 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
4222 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
4223 		buf[off++] = (pr_reg->pr_res_key & 0xff);
4224 		off += 4; /* Skip Over Reserved area */
4225 
4226 		/*
4227 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
4228 		 */
4229 		if (pr_reg->pr_reg_all_tg_pt)
4230 			buf[off] = 0x02;
4231 		/*
4232 		 * The struct se_lun pointer will be present for the
4233 		 * reservation holder for PR_HOLDER bit.
4234 		 *
4235 		 * Also, if this registration is the reservation
4236 		 * holder, fill in SCOPE and TYPE in the next byte.
4237 		 */
4238 		if (pr_reg->pr_res_holder) {
4239 			buf[off++] |= 0x01;
4240 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
4241 				     (pr_reg->pr_res_type & 0x0f);
4242 		} else
4243 			off += 2;
4244 
4245 		off += 4; /* Skip over reserved area */
4246 		/*
4247 		 * From spc4r17 6.3.15:
4248 		 *
4249 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4250 		 * IDENTIFIER field contains the relative port identifier (see
4251 		 * 3.1.120) of the target port that is part of the I_T nexus
4252 		 * described by this full status descriptor. If the ALL_TG_PT
4253 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4254 		 * IDENTIFIER field are not defined by this standard.
4255 		 */
4256 		if (!pr_reg->pr_reg_all_tg_pt) {
4257 			struct se_port *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
4258 
4259 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
4260 			buf[off++] = (port->sep_rtpi & 0xff);
4261 		} else
4262 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFIER */
4263 
4264 		/*
4265 		 * Now, have the $FABRIC_MOD fill in the protocol identifier
4266 		 */
4267 		desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id(se_tpg,
4268 				se_nacl, pr_reg, &format_code, &buf[off+4]);
4269 
4270 		spin_lock(&pr_tmpl->registration_lock);
4271 		atomic_dec(&pr_reg->pr_res_holders);
4272 		smp_mb__after_atomic_dec();
4273 		/*
4274 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4275 		 */
4276 		buf[off++] = ((desc_len >> 24) & 0xff);
4277 		buf[off++] = ((desc_len >> 16) & 0xff);
4278 		buf[off++] = ((desc_len >> 8) & 0xff);
4279 		buf[off++] = (desc_len & 0xff);
4280 		/*
4281 		 * Size of full desctipor header minus TransportID
4282 		 * containing $FABRIC_MOD specific) initiator device/port
4283 		 * WWN information.
4284 		 *
4285 		 *  See spc4r17 Section 6.13.5 Table 169
4286 		 */
4287 		add_desc_len = (24 + desc_len);
4288 
4289 		off += desc_len;
4290 		add_len += add_desc_len;
4291 	}
4292 	spin_unlock(&pr_tmpl->registration_lock);
4293 	/*
4294 	 * Set ADDITIONAL_LENGTH
4295 	 */
4296 	buf[4] = ((add_len >> 24) & 0xff);
4297 	buf[5] = ((add_len >> 16) & 0xff);
4298 	buf[6] = ((add_len >> 8) & 0xff);
4299 	buf[7] = (add_len & 0xff);
4300 
4301 	transport_kunmap_data_sg(cmd);
4302 
4303 	return 0;
4304 }
4305 
4306 int target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4307 {
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 		target_complete_cmd(cmd, GOOD);
4350 	return ret;
4351 }
4352 
4353 static int core_pt_reservation_check(struct se_cmd *cmd, u32 *pr_res_type)
4354 {
4355 	return 0;
4356 }
4357 
4358 static int core_pt_seq_non_holder(
4359 	struct se_cmd *cmd,
4360 	unsigned char *cdb,
4361 	u32 pr_reg_type)
4362 {
4363 	return 0;
4364 }
4365 
4366 int core_setup_reservations(struct se_device *dev, int force_pt)
4367 {
4368 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
4369 	struct t10_reservation *rest = &su_dev->t10_pr;
4370 	/*
4371 	 * If this device is from Target_Core_Mod/pSCSI, use the reservations
4372 	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
4373 	 * cause a problem because libata and some SATA RAID HBAs appear
4374 	 * under Linux/SCSI, but to emulate reservations themselves.
4375 	 */
4376 	if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
4377 	    !(dev->se_sub_dev->se_dev_attrib.emulate_reservations)) || force_pt) {
4378 		rest->res_type = SPC_PASSTHROUGH;
4379 		rest->pr_ops.t10_reservation_check = &core_pt_reservation_check;
4380 		rest->pr_ops.t10_seq_non_holder = &core_pt_seq_non_holder;
4381 		pr_debug("%s: Using SPC_PASSTHROUGH, no reservation"
4382 			" emulation\n", dev->transport->name);
4383 		return 0;
4384 	}
4385 	/*
4386 	 * If SPC-3 or above is reported by real or emulated struct se_device,
4387 	 * use emulated Persistent Reservations.
4388 	 */
4389 	if (dev->transport->get_device_rev(dev) >= SCSI_3) {
4390 		rest->res_type = SPC3_PERSISTENT_RESERVATIONS;
4391 		rest->pr_ops.t10_reservation_check = &core_scsi3_pr_reservation_check;
4392 		rest->pr_ops.t10_seq_non_holder = &core_scsi3_pr_seq_non_holder;
4393 		pr_debug("%s: Using SPC3_PERSISTENT_RESERVATIONS"
4394 			" emulation\n", dev->transport->name);
4395 	} else {
4396 		rest->res_type = SPC2_RESERVATIONS;
4397 		rest->pr_ops.t10_reservation_check = &core_scsi2_reservation_check;
4398 		rest->pr_ops.t10_seq_non_holder =
4399 				&core_scsi2_reservation_seq_non_holder;
4400 		pr_debug("%s: Using SPC2_RESERVATIONS emulation\n",
4401 			dev->transport->name);
4402 	}
4403 
4404 	return 0;
4405 }
4406