xref: /linux/drivers/target/target_core_pr.c (revision d229807f669ba3dea9f64467ee965051c4366aed)
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_device.h>
37 #include <target/target_core_tmr.h>
38 #include <target/target_core_tpg.h>
39 #include <target/target_core_transport.h>
40 #include <target/target_core_fabric_ops.h>
41 #include <target/target_core_configfs.h>
42 
43 #include "target_core_hba.h"
44 #include "target_core_pr.h"
45 #include "target_core_ua.h"
46 
47 /*
48  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
49  */
50 struct pr_transport_id_holder {
51 	int dest_local_nexus;
52 	struct t10_pr_registration *dest_pr_reg;
53 	struct se_portal_group *dest_tpg;
54 	struct se_node_acl *dest_node_acl;
55 	struct se_dev_entry *dest_se_deve;
56 	struct list_head dest_list;
57 };
58 
59 int core_pr_dump_initiator_port(
60 	struct t10_pr_registration *pr_reg,
61 	char *buf,
62 	u32 size)
63 {
64 	if (!pr_reg->isid_present_at_reg)
65 		return 0;
66 
67 	snprintf(buf, size, ",i,0x%s", &pr_reg->pr_reg_isid[0]);
68 	return 1;
69 }
70 
71 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
72 			struct t10_pr_registration *, int);
73 
74 static int core_scsi2_reservation_seq_non_holder(
75 	struct se_cmd *cmd,
76 	unsigned char *cdb,
77 	u32 pr_reg_type)
78 {
79 	switch (cdb[0]) {
80 	case INQUIRY:
81 	case RELEASE:
82 	case RELEASE_10:
83 		return 0;
84 	default:
85 		return 1;
86 	}
87 
88 	return 1;
89 }
90 
91 static int core_scsi2_reservation_check(struct se_cmd *cmd, u32 *pr_reg_type)
92 {
93 	struct se_device *dev = cmd->se_dev;
94 	struct se_session *sess = cmd->se_sess;
95 	int ret;
96 
97 	if (!sess)
98 		return 0;
99 
100 	spin_lock(&dev->dev_reservation_lock);
101 	if (!dev->dev_reserved_node_acl || !sess) {
102 		spin_unlock(&dev->dev_reservation_lock);
103 		return 0;
104 	}
105 	if (dev->dev_reserved_node_acl != sess->se_node_acl) {
106 		spin_unlock(&dev->dev_reservation_lock);
107 		return -EINVAL;
108 	}
109 	if (!(dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID)) {
110 		spin_unlock(&dev->dev_reservation_lock);
111 		return 0;
112 	}
113 	ret = (dev->dev_res_bin_isid == sess->sess_bin_isid) ? 0 : -EINVAL;
114 	spin_unlock(&dev->dev_reservation_lock);
115 
116 	return ret;
117 }
118 
119 static int core_scsi2_reservation_release(struct se_cmd *cmd)
120 {
121 	struct se_device *dev = cmd->se_dev;
122 	struct se_session *sess = cmd->se_sess;
123 	struct se_portal_group *tpg = sess->se_tpg;
124 
125 	if (!sess || !tpg)
126 		return 0;
127 
128 	spin_lock(&dev->dev_reservation_lock);
129 	if (!dev->dev_reserved_node_acl || !sess) {
130 		spin_unlock(&dev->dev_reservation_lock);
131 		return 0;
132 	}
133 
134 	if (dev->dev_reserved_node_acl != sess->se_node_acl) {
135 		spin_unlock(&dev->dev_reservation_lock);
136 		return 0;
137 	}
138 	dev->dev_reserved_node_acl = NULL;
139 	dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
140 	if (dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID) {
141 		dev->dev_res_bin_isid = 0;
142 		dev->dev_flags &= ~DF_SPC2_RESERVATIONS_WITH_ISID;
143 	}
144 	pr_debug("SCSI-2 Released reservation for %s LUN: %u ->"
145 		" MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
146 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
147 		sess->se_node_acl->initiatorname);
148 	spin_unlock(&dev->dev_reservation_lock);
149 
150 	return 0;
151 }
152 
153 static int core_scsi2_reservation_reserve(struct se_cmd *cmd)
154 {
155 	struct se_device *dev = cmd->se_dev;
156 	struct se_session *sess = cmd->se_sess;
157 	struct se_portal_group *tpg = sess->se_tpg;
158 
159 	if ((cmd->t_task_cdb[1] & 0x01) &&
160 	    (cmd->t_task_cdb[1] & 0x02)) {
161 		pr_err("LongIO and Obselete Bits set, returning"
162 				" ILLEGAL_REQUEST\n");
163 		return PYX_TRANSPORT_ILLEGAL_REQUEST;
164 	}
165 	/*
166 	 * This is currently the case for target_core_mod passthrough struct se_cmd
167 	 * ops
168 	 */
169 	if (!sess || !tpg)
170 		return 0;
171 
172 	spin_lock(&dev->dev_reservation_lock);
173 	if (dev->dev_reserved_node_acl &&
174 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
175 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
176 			tpg->se_tpg_tfo->get_fabric_name());
177 		pr_err("Original reserver LUN: %u %s\n",
178 			cmd->se_lun->unpacked_lun,
179 			dev->dev_reserved_node_acl->initiatorname);
180 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
181 			" from %s \n", cmd->se_lun->unpacked_lun,
182 			cmd->se_deve->mapped_lun,
183 			sess->se_node_acl->initiatorname);
184 		spin_unlock(&dev->dev_reservation_lock);
185 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
186 	}
187 
188 	dev->dev_reserved_node_acl = sess->se_node_acl;
189 	dev->dev_flags |= DF_SPC2_RESERVATIONS;
190 	if (sess->sess_bin_isid != 0) {
191 		dev->dev_res_bin_isid = sess->sess_bin_isid;
192 		dev->dev_flags |= DF_SPC2_RESERVATIONS_WITH_ISID;
193 	}
194 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
195 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
196 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
197 		sess->se_node_acl->initiatorname);
198 	spin_unlock(&dev->dev_reservation_lock);
199 
200 	return 0;
201 }
202 
203 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
204 					struct se_node_acl *, struct se_session *);
205 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
206 
207 /*
208  * Setup in target_core_transport.c:transport_generic_cmd_sequencer()
209  * and called via struct se_cmd->transport_emulate_cdb() in TCM processing
210  * thread context.
211  */
212 int core_scsi2_emulate_crh(struct se_cmd *cmd)
213 {
214 	struct se_session *se_sess = cmd->se_sess;
215 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
216 	struct t10_pr_registration *pr_reg;
217 	struct t10_reservation *pr_tmpl = &su_dev->t10_pr;
218 	unsigned char *cdb = &cmd->t_task_cdb[0];
219 	int crh = (su_dev->t10_pr.res_type == SPC3_PERSISTENT_RESERVATIONS);
220 	int conflict = 0;
221 
222 	if (!se_sess)
223 		return 0;
224 
225 	if (!crh)
226 		goto after_crh;
227 
228 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
229 			se_sess);
230 	if (pr_reg) {
231 		/*
232 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
233 		 * behavior
234 		 *
235 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
236 		 * status, but no reservation shall be established and the
237 		 * persistent reservation shall not be changed, if the command
238 		 * is received from a) and b) below.
239 		 *
240 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
241 		 * status, but the persistent reservation shall not be released,
242 		 * if the command is received from a) and b)
243 		 *
244 		 * a) An I_T nexus that is a persistent reservation holder; or
245 		 * b) An I_T nexus that is registered if a registrants only or
246 		 *    all registrants type persistent reservation is present.
247 		 *
248 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
249 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
250 		 * as defined in SPC-2.
251 		 */
252 		if (pr_reg->pr_res_holder) {
253 			core_scsi3_put_pr_reg(pr_reg);
254 			return 0;
255 		}
256 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
257 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
258 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
259 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
260 			core_scsi3_put_pr_reg(pr_reg);
261 			return 0;
262 		}
263 		core_scsi3_put_pr_reg(pr_reg);
264 		conflict = 1;
265 	} else {
266 		/*
267 		 * Following spc2r20 5.5.1 Reservations overview:
268 		 *
269 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
270 		 * command with the REGISTER or the REGISTER AND IGNORE
271 		 * EXISTING KEY service action and is still registered by any
272 		 * initiator, all RESERVE commands and all RELEASE commands
273 		 * regardless of initiator shall conflict and shall terminate
274 		 * with a RESERVATION CONFLICT status.
275 		 */
276 		spin_lock(&pr_tmpl->registration_lock);
277 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
278 		spin_unlock(&pr_tmpl->registration_lock);
279 	}
280 
281 	if (conflict) {
282 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
283 			" while active SPC-3 registrations exist,"
284 			" returning RESERVATION_CONFLICT\n");
285 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
286 	}
287 
288 after_crh:
289 	if ((cdb[0] == RESERVE) || (cdb[0] == RESERVE_10))
290 		return core_scsi2_reservation_reserve(cmd);
291 	else if ((cdb[0] == RELEASE) || (cdb[0] == RELEASE_10))
292 		return core_scsi2_reservation_release(cmd);
293 	else
294 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
295 }
296 
297 /*
298  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
299  *
300  * This function is called by those initiator ports who are *NOT*
301  * the active PR reservation holder when a reservation is present.
302  */
303 static int core_scsi3_pr_seq_non_holder(
304 	struct se_cmd *cmd,
305 	unsigned char *cdb,
306 	u32 pr_reg_type)
307 {
308 	struct se_dev_entry *se_deve;
309 	struct se_session *se_sess = cmd->se_sess;
310 	int other_cdb = 0, ignore_reg;
311 	int registered_nexus = 0, ret = 1; /* Conflict by default */
312 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
313 	int we = 0; /* Write Exclusive */
314 	int legacy = 0; /* Act like a legacy device and return
315 			 * RESERVATION CONFLICT on some CDBs */
316 	/*
317 	 * A legacy SPC-2 reservation is being held.
318 	 */
319 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS)
320 		return core_scsi2_reservation_seq_non_holder(cmd,
321 					cdb, pr_reg_type);
322 
323 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
324 	/*
325 	 * Determine if the registration should be ignored due to
326 	 * non-matching ISIDs in core_scsi3_pr_reservation_check().
327 	 */
328 	ignore_reg = (pr_reg_type & 0x80000000);
329 	if (ignore_reg)
330 		pr_reg_type &= ~0x80000000;
331 
332 	switch (pr_reg_type) {
333 	case PR_TYPE_WRITE_EXCLUSIVE:
334 		we = 1;
335 	case PR_TYPE_EXCLUSIVE_ACCESS:
336 		/*
337 		 * Some commands are only allowed for the persistent reservation
338 		 * holder.
339 		 */
340 		if ((se_deve->def_pr_registered) && !(ignore_reg))
341 			registered_nexus = 1;
342 		break;
343 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
344 		we = 1;
345 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
346 		/*
347 		 * Some commands are only allowed for registered I_T Nexuses.
348 		 */
349 		reg_only = 1;
350 		if ((se_deve->def_pr_registered) && !(ignore_reg))
351 			registered_nexus = 1;
352 		break;
353 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
354 		we = 1;
355 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
356 		/*
357 		 * Each registered I_T Nexus is a reservation holder.
358 		 */
359 		all_reg = 1;
360 		if ((se_deve->def_pr_registered) && !(ignore_reg))
361 			registered_nexus = 1;
362 		break;
363 	default:
364 		return -EINVAL;
365 	}
366 	/*
367 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
368 	 */
369 	switch (cdb[0]) {
370 	case SECURITY_PROTOCOL_IN:
371 		if (registered_nexus)
372 			return 0;
373 		ret = (we) ? 0 : 1;
374 		break;
375 	case MODE_SENSE:
376 	case MODE_SENSE_10:
377 	case READ_ATTRIBUTE:
378 	case READ_BUFFER:
379 	case RECEIVE_DIAGNOSTIC:
380 		if (legacy) {
381 			ret = 1;
382 			break;
383 		}
384 		if (registered_nexus) {
385 			ret = 0;
386 			break;
387 		}
388 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
389 		break;
390 	case PERSISTENT_RESERVE_OUT:
391 		/*
392 		 * This follows PERSISTENT_RESERVE_OUT service actions that
393 		 * are allowed in the presence of various reservations.
394 		 * See spc4r17, table 46
395 		 */
396 		switch (cdb[1] & 0x1f) {
397 		case PRO_CLEAR:
398 		case PRO_PREEMPT:
399 		case PRO_PREEMPT_AND_ABORT:
400 			ret = (registered_nexus) ? 0 : 1;
401 			break;
402 		case PRO_REGISTER:
403 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
404 			ret = 0;
405 			break;
406 		case PRO_REGISTER_AND_MOVE:
407 		case PRO_RESERVE:
408 			ret = 1;
409 			break;
410 		case PRO_RELEASE:
411 			ret = (registered_nexus) ? 0 : 1;
412 			break;
413 		default:
414 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
415 				" action: 0x%02x\n", cdb[1] & 0x1f);
416 			return -EINVAL;
417 		}
418 		break;
419 	case RELEASE:
420 	case RELEASE_10:
421 		/* Handled by CRH=1 in core_scsi2_emulate_crh() */
422 		ret = 0;
423 		break;
424 	case RESERVE:
425 	case RESERVE_10:
426 		/* Handled by CRH=1 in core_scsi2_emulate_crh() */
427 		ret = 0;
428 		break;
429 	case TEST_UNIT_READY:
430 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
431 		break;
432 	case MAINTENANCE_IN:
433 		switch (cdb[1] & 0x1f) {
434 		case MI_MANAGEMENT_PROTOCOL_IN:
435 			if (registered_nexus) {
436 				ret = 0;
437 				break;
438 			}
439 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
440 			break;
441 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
442 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
443 			if (legacy) {
444 				ret = 1;
445 				break;
446 			}
447 			if (registered_nexus) {
448 				ret = 0;
449 				break;
450 			}
451 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
452 			break;
453 		case MI_REPORT_ALIASES:
454 		case MI_REPORT_IDENTIFYING_INFORMATION:
455 		case MI_REPORT_PRIORITY:
456 		case MI_REPORT_TARGET_PGS:
457 		case MI_REPORT_TIMESTAMP:
458 			ret = 0; /* Allowed */
459 			break;
460 		default:
461 			pr_err("Unknown MI Service Action: 0x%02x\n",
462 				(cdb[1] & 0x1f));
463 			return -EINVAL;
464 		}
465 		break;
466 	case ACCESS_CONTROL_IN:
467 	case ACCESS_CONTROL_OUT:
468 	case INQUIRY:
469 	case LOG_SENSE:
470 	case READ_MEDIA_SERIAL_NUMBER:
471 	case REPORT_LUNS:
472 	case REQUEST_SENSE:
473 		ret = 0; /*/ Allowed CDBs */
474 		break;
475 	default:
476 		other_cdb = 1;
477 		break;
478 	}
479 	/*
480 	 * Case where the CDB is explicitly allowed in the above switch
481 	 * statement.
482 	 */
483 	if (!ret && !other_cdb) {
484 #if 0
485 		pr_debug("Allowing explict CDB: 0x%02x for %s"
486 			" reservation holder\n", cdb[0],
487 			core_scsi3_pr_dump_type(pr_reg_type));
488 #endif
489 		return ret;
490 	}
491 	/*
492 	 * Check if write exclusive initiator ports *NOT* holding the
493 	 * WRITE_EXCLUSIVE_* reservation.
494 	 */
495 	if ((we) && !(registered_nexus)) {
496 		if (cmd->data_direction == DMA_TO_DEVICE) {
497 			/*
498 			 * Conflict for write exclusive
499 			 */
500 			pr_debug("%s Conflict for unregistered nexus"
501 				" %s CDB: 0x%02x to %s reservation\n",
502 				transport_dump_cmd_direction(cmd),
503 				se_sess->se_node_acl->initiatorname, cdb[0],
504 				core_scsi3_pr_dump_type(pr_reg_type));
505 			return 1;
506 		} else {
507 			/*
508 			 * Allow non WRITE CDBs for all Write Exclusive
509 			 * PR TYPEs to pass for registered and
510 			 * non-registered_nexuxes NOT holding the reservation.
511 			 *
512 			 * We only make noise for the unregisterd nexuses,
513 			 * as we expect registered non-reservation holding
514 			 * nexuses to issue CDBs.
515 			 */
516 #if 0
517 			if (!registered_nexus) {
518 				pr_debug("Allowing implict CDB: 0x%02x"
519 					" for %s reservation on unregistered"
520 					" nexus\n", cdb[0],
521 					core_scsi3_pr_dump_type(pr_reg_type));
522 			}
523 #endif
524 			return 0;
525 		}
526 	} else if ((reg_only) || (all_reg)) {
527 		if (registered_nexus) {
528 			/*
529 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
530 			 * allow commands from registered nexuses.
531 			 */
532 #if 0
533 			pr_debug("Allowing implict CDB: 0x%02x for %s"
534 				" reservation\n", cdb[0],
535 				core_scsi3_pr_dump_type(pr_reg_type));
536 #endif
537 			return 0;
538 		}
539 	}
540 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
541 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
542 		(registered_nexus) ? "" : "un",
543 		se_sess->se_node_acl->initiatorname, cdb[0],
544 		core_scsi3_pr_dump_type(pr_reg_type));
545 
546 	return 1; /* Conflict by default */
547 }
548 
549 static u32 core_scsi3_pr_generation(struct se_device *dev)
550 {
551 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
552 	u32 prg;
553 	/*
554 	 * PRGeneration field shall contain the value of a 32-bit wrapping
555 	 * counter mainted by the device server.
556 	 *
557 	 * Note that this is done regardless of Active Persist across
558 	 * Target PowerLoss (APTPL)
559 	 *
560 	 * See spc4r17 section 6.3.12 READ_KEYS service action
561 	 */
562 	spin_lock(&dev->dev_reservation_lock);
563 	prg = su_dev->t10_pr.pr_generation++;
564 	spin_unlock(&dev->dev_reservation_lock);
565 
566 	return prg;
567 }
568 
569 static int core_scsi3_pr_reservation_check(
570 	struct se_cmd *cmd,
571 	u32 *pr_reg_type)
572 {
573 	struct se_device *dev = cmd->se_dev;
574 	struct se_session *sess = cmd->se_sess;
575 	int ret;
576 
577 	if (!sess)
578 		return 0;
579 	/*
580 	 * A legacy SPC-2 reservation is being held.
581 	 */
582 	if (dev->dev_flags & DF_SPC2_RESERVATIONS)
583 		return core_scsi2_reservation_check(cmd, pr_reg_type);
584 
585 	spin_lock(&dev->dev_reservation_lock);
586 	if (!dev->dev_pr_res_holder) {
587 		spin_unlock(&dev->dev_reservation_lock);
588 		return 0;
589 	}
590 	*pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
591 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
592 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl) {
593 		spin_unlock(&dev->dev_reservation_lock);
594 		return -EINVAL;
595 	}
596 	if (!dev->dev_pr_res_holder->isid_present_at_reg) {
597 		spin_unlock(&dev->dev_reservation_lock);
598 		return 0;
599 	}
600 	ret = (dev->dev_pr_res_holder->pr_reg_bin_isid ==
601 	       sess->sess_bin_isid) ? 0 : -EINVAL;
602 	/*
603 	 * Use bit in *pr_reg_type to notify ISID mismatch in
604 	 * core_scsi3_pr_seq_non_holder().
605 	 */
606 	if (ret != 0)
607 		*pr_reg_type |= 0x80000000;
608 	spin_unlock(&dev->dev_reservation_lock);
609 
610 	return ret;
611 }
612 
613 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
614 	struct se_device *dev,
615 	struct se_node_acl *nacl,
616 	struct se_dev_entry *deve,
617 	unsigned char *isid,
618 	u64 sa_res_key,
619 	int all_tg_pt,
620 	int aptpl)
621 {
622 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
623 	struct t10_pr_registration *pr_reg;
624 
625 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
626 	if (!pr_reg) {
627 		pr_err("Unable to allocate struct t10_pr_registration\n");
628 		return NULL;
629 	}
630 
631 	pr_reg->pr_aptpl_buf = kzalloc(su_dev->t10_pr.pr_aptpl_buf_len,
632 					GFP_ATOMIC);
633 	if (!pr_reg->pr_aptpl_buf) {
634 		pr_err("Unable to allocate pr_reg->pr_aptpl_buf\n");
635 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
636 		return NULL;
637 	}
638 
639 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
640 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
641 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
642 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
643 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
644 	atomic_set(&pr_reg->pr_res_holders, 0);
645 	pr_reg->pr_reg_nacl = nacl;
646 	pr_reg->pr_reg_deve = deve;
647 	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
648 	pr_reg->pr_aptpl_target_lun = deve->se_lun->unpacked_lun;
649 	pr_reg->pr_res_key = sa_res_key;
650 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
651 	pr_reg->pr_reg_aptpl = aptpl;
652 	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
653 	/*
654 	 * If an ISID value for this SCSI Initiator Port exists,
655 	 * save it to the registration now.
656 	 */
657 	if (isid != NULL) {
658 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
659 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
660 		pr_reg->isid_present_at_reg = 1;
661 	}
662 
663 	return pr_reg;
664 }
665 
666 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
667 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
668 
669 /*
670  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
671  * modes.
672  */
673 static struct t10_pr_registration *__core_scsi3_alloc_registration(
674 	struct se_device *dev,
675 	struct se_node_acl *nacl,
676 	struct se_dev_entry *deve,
677 	unsigned char *isid,
678 	u64 sa_res_key,
679 	int all_tg_pt,
680 	int aptpl)
681 {
682 	struct se_dev_entry *deve_tmp;
683 	struct se_node_acl *nacl_tmp;
684 	struct se_port *port, *port_tmp;
685 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
686 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
687 	int ret;
688 	/*
689 	 * Create a registration for the I_T Nexus upon which the
690 	 * PROUT REGISTER was received.
691 	 */
692 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, deve, isid,
693 			sa_res_key, all_tg_pt, aptpl);
694 	if (!pr_reg)
695 		return NULL;
696 	/*
697 	 * Return pointer to pr_reg for ALL_TG_PT=0
698 	 */
699 	if (!all_tg_pt)
700 		return pr_reg;
701 	/*
702 	 * Create list of matching SCSI Initiator Port registrations
703 	 * for ALL_TG_PT=1
704 	 */
705 	spin_lock(&dev->se_port_lock);
706 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
707 		atomic_inc(&port->sep_tg_pt_ref_cnt);
708 		smp_mb__after_atomic_inc();
709 		spin_unlock(&dev->se_port_lock);
710 
711 		spin_lock_bh(&port->sep_alua_lock);
712 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
713 					alua_port_list) {
714 			/*
715 			 * This pointer will be NULL for demo mode MappedLUNs
716 			 * that have not been make explict via a ConfigFS
717 			 * MappedLUN group for the SCSI Initiator Node ACL.
718 			 */
719 			if (!deve_tmp->se_lun_acl)
720 				continue;
721 
722 			nacl_tmp = deve_tmp->se_lun_acl->se_lun_nacl;
723 			/*
724 			 * Skip the matching struct se_node_acl that is allocated
725 			 * above..
726 			 */
727 			if (nacl == nacl_tmp)
728 				continue;
729 			/*
730 			 * Only perform PR registrations for target ports on
731 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
732 			 * arrived.
733 			 */
734 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
735 				continue;
736 			/*
737 			 * Look for a matching Initiator Node ACL in ASCII format
738 			 */
739 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
740 				continue;
741 
742 			atomic_inc(&deve_tmp->pr_ref_count);
743 			smp_mb__after_atomic_inc();
744 			spin_unlock_bh(&port->sep_alua_lock);
745 			/*
746 			 * Grab a configfs group dependency that is released
747 			 * for the exception path at label out: below, or upon
748 			 * completion of adding ALL_TG_PT=1 registrations in
749 			 * __core_scsi3_add_registration()
750 			 */
751 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
752 			if (ret < 0) {
753 				pr_err("core_scsi3_lunacl_depend"
754 						"_item() failed\n");
755 				atomic_dec(&port->sep_tg_pt_ref_cnt);
756 				smp_mb__after_atomic_dec();
757 				atomic_dec(&deve_tmp->pr_ref_count);
758 				smp_mb__after_atomic_dec();
759 				goto out;
760 			}
761 			/*
762 			 * Located a matching SCSI Initiator Port on a different
763 			 * port, allocate the pr_reg_atp and attach it to the
764 			 * pr_reg->pr_reg_atp_list that will be processed once
765 			 * the original *pr_reg is processed in
766 			 * __core_scsi3_add_registration()
767 			 */
768 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
769 						nacl_tmp, deve_tmp, NULL,
770 						sa_res_key, all_tg_pt, aptpl);
771 			if (!pr_reg_atp) {
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 				core_scsi3_lunacl_undepend_item(deve_tmp);
777 				goto out;
778 			}
779 
780 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
781 				      &pr_reg->pr_reg_atp_list);
782 			spin_lock_bh(&port->sep_alua_lock);
783 		}
784 		spin_unlock_bh(&port->sep_alua_lock);
785 
786 		spin_lock(&dev->se_port_lock);
787 		atomic_dec(&port->sep_tg_pt_ref_cnt);
788 		smp_mb__after_atomic_dec();
789 	}
790 	spin_unlock(&dev->se_port_lock);
791 
792 	return pr_reg;
793 out:
794 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
795 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
796 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
797 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
798 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
799 	}
800 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
801 	return NULL;
802 }
803 
804 int core_scsi3_alloc_aptpl_registration(
805 	struct t10_reservation *pr_tmpl,
806 	u64 sa_res_key,
807 	unsigned char *i_port,
808 	unsigned char *isid,
809 	u32 mapped_lun,
810 	unsigned char *t_port,
811 	u16 tpgt,
812 	u32 target_lun,
813 	int res_holder,
814 	int all_tg_pt,
815 	u8 type)
816 {
817 	struct t10_pr_registration *pr_reg;
818 
819 	if (!i_port || !t_port || !sa_res_key) {
820 		pr_err("Illegal parameters for APTPL registration\n");
821 		return -EINVAL;
822 	}
823 
824 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
825 	if (!pr_reg) {
826 		pr_err("Unable to allocate struct t10_pr_registration\n");
827 		return -ENOMEM;
828 	}
829 	pr_reg->pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len, GFP_KERNEL);
830 
831 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
832 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
833 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
834 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
835 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
836 	atomic_set(&pr_reg->pr_res_holders, 0);
837 	pr_reg->pr_reg_nacl = NULL;
838 	pr_reg->pr_reg_deve = NULL;
839 	pr_reg->pr_res_mapped_lun = mapped_lun;
840 	pr_reg->pr_aptpl_target_lun = target_lun;
841 	pr_reg->pr_res_key = sa_res_key;
842 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
843 	pr_reg->pr_reg_aptpl = 1;
844 	pr_reg->pr_reg_tg_pt_lun = NULL;
845 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
846 	pr_reg->pr_res_type = type;
847 	/*
848 	 * If an ISID value had been saved in APTPL metadata for this
849 	 * SCSI Initiator Port, restore it now.
850 	 */
851 	if (isid != NULL) {
852 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
853 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
854 		pr_reg->isid_present_at_reg = 1;
855 	}
856 	/*
857 	 * Copy the i_port and t_port information from caller.
858 	 */
859 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
860 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
861 	pr_reg->pr_reg_tpgt = tpgt;
862 	/*
863 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
864 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
865 	 * the Initiator Node LUN ACL from the fabric module is created for
866 	 * this registration.
867 	 */
868 	pr_reg->pr_res_holder = res_holder;
869 
870 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
871 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
872 			" metadata\n", (res_holder) ? "+reservation" : "");
873 	return 0;
874 }
875 
876 static void core_scsi3_aptpl_reserve(
877 	struct se_device *dev,
878 	struct se_portal_group *tpg,
879 	struct se_node_acl *node_acl,
880 	struct t10_pr_registration *pr_reg)
881 {
882 	char i_buf[PR_REG_ISID_ID_LEN];
883 	int prf_isid;
884 
885 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
886 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
887 				PR_REG_ISID_ID_LEN);
888 
889 	spin_lock(&dev->dev_reservation_lock);
890 	dev->dev_pr_res_holder = pr_reg;
891 	spin_unlock(&dev->dev_reservation_lock);
892 
893 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
894 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
895 		tpg->se_tpg_tfo->get_fabric_name(),
896 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
897 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
898 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
899 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
900 		(prf_isid) ? &i_buf[0] : "");
901 }
902 
903 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
904 				struct t10_pr_registration *, int, int);
905 
906 static int __core_scsi3_check_aptpl_registration(
907 	struct se_device *dev,
908 	struct se_portal_group *tpg,
909 	struct se_lun *lun,
910 	u32 target_lun,
911 	struct se_node_acl *nacl,
912 	struct se_dev_entry *deve)
913 {
914 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
915 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
916 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
917 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
918 	u16 tpgt;
919 
920 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
921 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
922 	/*
923 	 * Copy Initiator Port information from struct se_node_acl
924 	 */
925 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
926 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
927 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
928 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
929 	/*
930 	 * Look for the matching registrations+reservation from those
931 	 * created from APTPL metadata.  Note that multiple registrations
932 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
933 	 * TransportIDs.
934 	 */
935 	spin_lock(&pr_tmpl->aptpl_reg_lock);
936 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
937 				pr_reg_aptpl_list) {
938 		if (!strcmp(pr_reg->pr_iport, i_port) &&
939 		     (pr_reg->pr_res_mapped_lun == deve->mapped_lun) &&
940 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
941 		     (pr_reg->pr_reg_tpgt == tpgt) &&
942 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
943 
944 			pr_reg->pr_reg_nacl = nacl;
945 			pr_reg->pr_reg_deve = deve;
946 			pr_reg->pr_reg_tg_pt_lun = lun;
947 
948 			list_del(&pr_reg->pr_reg_aptpl_list);
949 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
950 			/*
951 			 * At this point all of the pointers in *pr_reg will
952 			 * be setup, so go ahead and add the registration.
953 			 */
954 
955 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
956 			/*
957 			 * If this registration is the reservation holder,
958 			 * make that happen now..
959 			 */
960 			if (pr_reg->pr_res_holder)
961 				core_scsi3_aptpl_reserve(dev, tpg,
962 						nacl, pr_reg);
963 			/*
964 			 * Reenable pr_aptpl_active to accept new metadata
965 			 * updates once the SCSI device is active again..
966 			 */
967 			spin_lock(&pr_tmpl->aptpl_reg_lock);
968 			pr_tmpl->pr_aptpl_active = 1;
969 		}
970 	}
971 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
972 
973 	return 0;
974 }
975 
976 int core_scsi3_check_aptpl_registration(
977 	struct se_device *dev,
978 	struct se_portal_group *tpg,
979 	struct se_lun *lun,
980 	struct se_lun_acl *lun_acl)
981 {
982 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
983 	struct se_node_acl *nacl = lun_acl->se_lun_nacl;
984 	struct se_dev_entry *deve = &nacl->device_list[lun_acl->mapped_lun];
985 
986 	if (su_dev->t10_pr.res_type != SPC3_PERSISTENT_RESERVATIONS)
987 		return 0;
988 
989 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
990 				lun->unpacked_lun, nacl, deve);
991 }
992 
993 static void __core_scsi3_dump_registration(
994 	struct target_core_fabric_ops *tfo,
995 	struct se_device *dev,
996 	struct se_node_acl *nacl,
997 	struct t10_pr_registration *pr_reg,
998 	int register_type)
999 {
1000 	struct se_portal_group *se_tpg = nacl->se_tpg;
1001 	char i_buf[PR_REG_ISID_ID_LEN];
1002 	int prf_isid;
1003 
1004 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
1005 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1006 				PR_REG_ISID_ID_LEN);
1007 
1008 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1009 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == 2) ?
1010 		"_AND_MOVE" : (register_type == 1) ?
1011 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1012 		(prf_isid) ? i_buf : "");
1013 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1014 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
1015 		tfo->tpg_get_tag(se_tpg));
1016 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1017 		" Port(s)\n",  tfo->get_fabric_name(),
1018 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1019 		dev->transport->name);
1020 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1021 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
1022 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1023 		pr_reg->pr_reg_aptpl);
1024 }
1025 
1026 /*
1027  * this function can be called with struct se_device->dev_reservation_lock
1028  * when register_move = 1
1029  */
1030 static void __core_scsi3_add_registration(
1031 	struct se_device *dev,
1032 	struct se_node_acl *nacl,
1033 	struct t10_pr_registration *pr_reg,
1034 	int register_type,
1035 	int register_move)
1036 {
1037 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1038 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1039 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1040 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1041 
1042 	/*
1043 	 * Increment PRgeneration counter for struct se_device upon a successful
1044 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1045 	 *
1046 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1047 	 * action, the struct se_device->dev_reservation_lock will already be held,
1048 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1049 	 * for the REGISTER.
1050 	 */
1051 	pr_reg->pr_res_generation = (register_move) ?
1052 			su_dev->t10_pr.pr_generation++ :
1053 			core_scsi3_pr_generation(dev);
1054 
1055 	spin_lock(&pr_tmpl->registration_lock);
1056 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1057 	pr_reg->pr_reg_deve->def_pr_registered = 1;
1058 
1059 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1060 	spin_unlock(&pr_tmpl->registration_lock);
1061 	/*
1062 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1063 	 */
1064 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1065 		return;
1066 	/*
1067 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1068 	 * allocated in __core_scsi3_alloc_registration()
1069 	 */
1070 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1071 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1072 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1073 
1074 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1075 
1076 		spin_lock(&pr_tmpl->registration_lock);
1077 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1078 			      &pr_tmpl->registration_list);
1079 		pr_reg_tmp->pr_reg_deve->def_pr_registered = 1;
1080 
1081 		__core_scsi3_dump_registration(tfo, dev,
1082 				pr_reg_tmp->pr_reg_nacl, pr_reg_tmp,
1083 				register_type);
1084 		spin_unlock(&pr_tmpl->registration_lock);
1085 		/*
1086 		 * Drop configfs group dependency reference from
1087 		 * __core_scsi3_alloc_registration()
1088 		 */
1089 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1090 	}
1091 }
1092 
1093 static int core_scsi3_alloc_registration(
1094 	struct se_device *dev,
1095 	struct se_node_acl *nacl,
1096 	struct se_dev_entry *deve,
1097 	unsigned char *isid,
1098 	u64 sa_res_key,
1099 	int all_tg_pt,
1100 	int aptpl,
1101 	int register_type,
1102 	int register_move)
1103 {
1104 	struct t10_pr_registration *pr_reg;
1105 
1106 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, deve, isid,
1107 			sa_res_key, all_tg_pt, aptpl);
1108 	if (!pr_reg)
1109 		return -EPERM;
1110 
1111 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1112 			register_type, register_move);
1113 	return 0;
1114 }
1115 
1116 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1117 	struct se_device *dev,
1118 	struct se_node_acl *nacl,
1119 	unsigned char *isid)
1120 {
1121 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1122 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1123 	struct se_portal_group *tpg;
1124 
1125 	spin_lock(&pr_tmpl->registration_lock);
1126 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1127 			&pr_tmpl->registration_list, pr_reg_list) {
1128 		/*
1129 		 * First look for a matching struct se_node_acl
1130 		 */
1131 		if (pr_reg->pr_reg_nacl != nacl)
1132 			continue;
1133 
1134 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1135 		/*
1136 		 * If this registration does NOT contain a fabric provided
1137 		 * ISID, then we have found a match.
1138 		 */
1139 		if (!pr_reg->isid_present_at_reg) {
1140 			/*
1141 			 * Determine if this SCSI device server requires that
1142 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1143 			 * for fabric modules (iSCSI) requiring them.
1144 			 */
1145 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1146 				if (dev->se_sub_dev->se_dev_attrib.enforce_pr_isids)
1147 					continue;
1148 			}
1149 			atomic_inc(&pr_reg->pr_res_holders);
1150 			smp_mb__after_atomic_inc();
1151 			spin_unlock(&pr_tmpl->registration_lock);
1152 			return pr_reg;
1153 		}
1154 		/*
1155 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1156 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1157 		 * matching ISID to be provided by the local SCSI Initiator Port.
1158 		 */
1159 		if (!isid)
1160 			continue;
1161 		if (strcmp(isid, pr_reg->pr_reg_isid))
1162 			continue;
1163 
1164 		atomic_inc(&pr_reg->pr_res_holders);
1165 		smp_mb__after_atomic_inc();
1166 		spin_unlock(&pr_tmpl->registration_lock);
1167 		return pr_reg;
1168 	}
1169 	spin_unlock(&pr_tmpl->registration_lock);
1170 
1171 	return NULL;
1172 }
1173 
1174 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1175 	struct se_device *dev,
1176 	struct se_node_acl *nacl,
1177 	struct se_session *sess)
1178 {
1179 	struct se_portal_group *tpg = nacl->se_tpg;
1180 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1181 
1182 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1183 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1184 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1185 					PR_REG_ISID_LEN);
1186 		isid_ptr = &buf[0];
1187 	}
1188 
1189 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1190 }
1191 
1192 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1193 {
1194 	atomic_dec(&pr_reg->pr_res_holders);
1195 	smp_mb__after_atomic_dec();
1196 }
1197 
1198 static int core_scsi3_check_implict_release(
1199 	struct se_device *dev,
1200 	struct t10_pr_registration *pr_reg)
1201 {
1202 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1203 	struct t10_pr_registration *pr_res_holder;
1204 	int ret = 0;
1205 
1206 	spin_lock(&dev->dev_reservation_lock);
1207 	pr_res_holder = dev->dev_pr_res_holder;
1208 	if (!pr_res_holder) {
1209 		spin_unlock(&dev->dev_reservation_lock);
1210 		return ret;
1211 	}
1212 	if (pr_res_holder == pr_reg) {
1213 		/*
1214 		 * Perform an implict RELEASE if the registration that
1215 		 * is being released is holding the reservation.
1216 		 *
1217 		 * From spc4r17, section 5.7.11.1:
1218 		 *
1219 		 * e) If the I_T nexus is the persistent reservation holder
1220 		 *    and the persistent reservation is not an all registrants
1221 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1222 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1223 		 *    service action with the SERVICE ACTION RESERVATION KEY
1224 		 *    field set to zero (see 5.7.11.3).
1225 		 */
1226 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0);
1227 		ret = 1;
1228 		/*
1229 		 * For 'All Registrants' reservation types, all existing
1230 		 * registrations are still processed as reservation holders
1231 		 * in core_scsi3_pr_seq_non_holder() after the initial
1232 		 * reservation holder is implictly released here.
1233 		 */
1234 	} else if (pr_reg->pr_reg_all_tg_pt &&
1235 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1236 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1237 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1238 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1239 			" UNREGISTER while existing reservation with matching"
1240 			" key 0x%016Lx is present from another SCSI Initiator"
1241 			" Port\n", pr_reg->pr_res_key);
1242 		ret = -EPERM;
1243 	}
1244 	spin_unlock(&dev->dev_reservation_lock);
1245 
1246 	return ret;
1247 }
1248 
1249 /*
1250  * Called with struct t10_reservation->registration_lock held.
1251  */
1252 static void __core_scsi3_free_registration(
1253 	struct se_device *dev,
1254 	struct t10_pr_registration *pr_reg,
1255 	struct list_head *preempt_and_abort_list,
1256 	int dec_holders)
1257 {
1258 	struct target_core_fabric_ops *tfo =
1259 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1260 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1261 	char i_buf[PR_REG_ISID_ID_LEN];
1262 	int prf_isid;
1263 
1264 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1265 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1266 				PR_REG_ISID_ID_LEN);
1267 
1268 	pr_reg->pr_reg_deve->def_pr_registered = 0;
1269 	pr_reg->pr_reg_deve->pr_res_key = 0;
1270 	list_del(&pr_reg->pr_reg_list);
1271 	/*
1272 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1273 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1274 	 */
1275 	if (dec_holders)
1276 		core_scsi3_put_pr_reg(pr_reg);
1277 	/*
1278 	 * Wait until all reference from any other I_T nexuses for this
1279 	 * *pr_reg have been released.  Because list_del() is called above,
1280 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1281 	 * count back to zero, and we release *pr_reg.
1282 	 */
1283 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1284 		spin_unlock(&pr_tmpl->registration_lock);
1285 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1286 				tfo->get_fabric_name());
1287 		cpu_relax();
1288 		spin_lock(&pr_tmpl->registration_lock);
1289 	}
1290 
1291 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1292 		" Node: %s%s\n", tfo->get_fabric_name(),
1293 		pr_reg->pr_reg_nacl->initiatorname,
1294 		(prf_isid) ? &i_buf[0] : "");
1295 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1296 		" Port(s)\n", tfo->get_fabric_name(),
1297 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1298 		dev->transport->name);
1299 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1300 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1301 		pr_reg->pr_res_generation);
1302 
1303 	if (!preempt_and_abort_list) {
1304 		pr_reg->pr_reg_deve = NULL;
1305 		pr_reg->pr_reg_nacl = NULL;
1306 		kfree(pr_reg->pr_aptpl_buf);
1307 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1308 		return;
1309 	}
1310 	/*
1311 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1312 	 * are released once the ABORT_TASK_SET has completed..
1313 	 */
1314 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1315 }
1316 
1317 void core_scsi3_free_pr_reg_from_nacl(
1318 	struct se_device *dev,
1319 	struct se_node_acl *nacl)
1320 {
1321 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1322 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1323 	/*
1324 	 * If the passed se_node_acl matches the reservation holder,
1325 	 * release the reservation.
1326 	 */
1327 	spin_lock(&dev->dev_reservation_lock);
1328 	pr_res_holder = dev->dev_pr_res_holder;
1329 	if ((pr_res_holder != NULL) &&
1330 	    (pr_res_holder->pr_reg_nacl == nacl))
1331 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0);
1332 	spin_unlock(&dev->dev_reservation_lock);
1333 	/*
1334 	 * Release any registration associated with the struct se_node_acl.
1335 	 */
1336 	spin_lock(&pr_tmpl->registration_lock);
1337 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1338 			&pr_tmpl->registration_list, pr_reg_list) {
1339 
1340 		if (pr_reg->pr_reg_nacl != nacl)
1341 			continue;
1342 
1343 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1344 	}
1345 	spin_unlock(&pr_tmpl->registration_lock);
1346 }
1347 
1348 void core_scsi3_free_all_registrations(
1349 	struct se_device *dev)
1350 {
1351 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1352 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1353 
1354 	spin_lock(&dev->dev_reservation_lock);
1355 	pr_res_holder = dev->dev_pr_res_holder;
1356 	if (pr_res_holder != NULL) {
1357 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1358 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1359 				pr_res_holder, 0);
1360 	}
1361 	spin_unlock(&dev->dev_reservation_lock);
1362 
1363 	spin_lock(&pr_tmpl->registration_lock);
1364 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1365 			&pr_tmpl->registration_list, pr_reg_list) {
1366 
1367 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1368 	}
1369 	spin_unlock(&pr_tmpl->registration_lock);
1370 
1371 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1372 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1373 				pr_reg_aptpl_list) {
1374 		list_del(&pr_reg->pr_reg_aptpl_list);
1375 		kfree(pr_reg->pr_aptpl_buf);
1376 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1377 	}
1378 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1379 }
1380 
1381 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1382 {
1383 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1384 			&tpg->tpg_group.cg_item);
1385 }
1386 
1387 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1388 {
1389 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1390 			&tpg->tpg_group.cg_item);
1391 
1392 	atomic_dec(&tpg->tpg_pr_ref_count);
1393 	smp_mb__after_atomic_dec();
1394 }
1395 
1396 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1397 {
1398 	struct se_portal_group *tpg = nacl->se_tpg;
1399 
1400 	if (nacl->dynamic_node_acl)
1401 		return 0;
1402 
1403 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1404 			&nacl->acl_group.cg_item);
1405 }
1406 
1407 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1408 {
1409 	struct se_portal_group *tpg = nacl->se_tpg;
1410 
1411 	if (nacl->dynamic_node_acl) {
1412 		atomic_dec(&nacl->acl_pr_ref_count);
1413 		smp_mb__after_atomic_dec();
1414 		return;
1415 	}
1416 
1417 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1418 			&nacl->acl_group.cg_item);
1419 
1420 	atomic_dec(&nacl->acl_pr_ref_count);
1421 	smp_mb__after_atomic_dec();
1422 }
1423 
1424 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1425 {
1426 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1427 	struct se_node_acl *nacl;
1428 	struct se_portal_group *tpg;
1429 	/*
1430 	 * For nacl->dynamic_node_acl=1
1431 	 */
1432 	if (!lun_acl)
1433 		return 0;
1434 
1435 	nacl = lun_acl->se_lun_nacl;
1436 	tpg = nacl->se_tpg;
1437 
1438 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1439 			&lun_acl->se_lun_group.cg_item);
1440 }
1441 
1442 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1443 {
1444 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1445 	struct se_node_acl *nacl;
1446 	struct se_portal_group *tpg;
1447 	/*
1448 	 * For nacl->dynamic_node_acl=1
1449 	 */
1450 	if (!lun_acl) {
1451 		atomic_dec(&se_deve->pr_ref_count);
1452 		smp_mb__after_atomic_dec();
1453 		return;
1454 	}
1455 	nacl = lun_acl->se_lun_nacl;
1456 	tpg = nacl->se_tpg;
1457 
1458 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1459 			&lun_acl->se_lun_group.cg_item);
1460 
1461 	atomic_dec(&se_deve->pr_ref_count);
1462 	smp_mb__after_atomic_dec();
1463 }
1464 
1465 static int core_scsi3_decode_spec_i_port(
1466 	struct se_cmd *cmd,
1467 	struct se_portal_group *tpg,
1468 	unsigned char *l_isid,
1469 	u64 sa_res_key,
1470 	int all_tg_pt,
1471 	int aptpl)
1472 {
1473 	struct se_device *dev = cmd->se_dev;
1474 	struct se_port *tmp_port;
1475 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1476 	struct se_session *se_sess = cmd->se_sess;
1477 	struct se_node_acl *dest_node_acl = NULL;
1478 	struct se_dev_entry *dest_se_deve = NULL, *local_se_deve;
1479 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1480 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1481 	struct list_head tid_dest_list;
1482 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1483 	struct target_core_fabric_ops *tmp_tf_ops;
1484 	unsigned char *buf;
1485 	unsigned char *ptr, *i_str = NULL, proto_ident, tmp_proto_ident;
1486 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
1487 	u32 tpdl, tid_len = 0;
1488 	int ret, dest_local_nexus, prf_isid;
1489 	u32 dest_rtpi = 0;
1490 
1491 	memset(dest_iport, 0, 64);
1492 	INIT_LIST_HEAD(&tid_dest_list);
1493 
1494 	local_se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
1495 	/*
1496 	 * Allocate a struct pr_transport_id_holder and setup the
1497 	 * local_node_acl and local_se_deve pointers and add to
1498 	 * struct list_head tid_dest_list for add registration
1499 	 * processing in the loop of tid_dest_list below.
1500 	 */
1501 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1502 	if (!tidh_new) {
1503 		pr_err("Unable to allocate tidh_new\n");
1504 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1505 	}
1506 	INIT_LIST_HEAD(&tidh_new->dest_list);
1507 	tidh_new->dest_tpg = tpg;
1508 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1509 	tidh_new->dest_se_deve = local_se_deve;
1510 
1511 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1512 				se_sess->se_node_acl, local_se_deve, l_isid,
1513 				sa_res_key, all_tg_pt, aptpl);
1514 	if (!local_pr_reg) {
1515 		kfree(tidh_new);
1516 		return PYX_TRANSPORT_LU_COMM_FAILURE;
1517 	}
1518 	tidh_new->dest_pr_reg = local_pr_reg;
1519 	/*
1520 	 * The local I_T nexus does not hold any configfs dependances,
1521 	 * so we set tid_h->dest_local_nexus=1 to prevent the
1522 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1523 	 */
1524 	tidh_new->dest_local_nexus = 1;
1525 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1526 
1527 	buf = transport_kmap_first_data_page(cmd);
1528 	/*
1529 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1530 	 * first extract TransportID Parameter Data Length, and make sure
1531 	 * the value matches up to the SCSI expected data transfer length.
1532 	 */
1533 	tpdl = (buf[24] & 0xff) << 24;
1534 	tpdl |= (buf[25] & 0xff) << 16;
1535 	tpdl |= (buf[26] & 0xff) << 8;
1536 	tpdl |= buf[27] & 0xff;
1537 
1538 	if ((tpdl + 28) != cmd->data_length) {
1539 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1540 			" does not equal CDB data_length: %u\n", tpdl,
1541 			cmd->data_length);
1542 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1543 		goto out;
1544 	}
1545 	/*
1546 	 * Start processing the received transport IDs using the
1547 	 * receiving I_T Nexus portal's fabric dependent methods to
1548 	 * obtain the SCSI Initiator Port/Device Identifiers.
1549 	 */
1550 	ptr = &buf[28];
1551 
1552 	while (tpdl > 0) {
1553 		proto_ident = (ptr[0] & 0x0f);
1554 		dest_tpg = NULL;
1555 
1556 		spin_lock(&dev->se_port_lock);
1557 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1558 			tmp_tpg = tmp_port->sep_tpg;
1559 			if (!tmp_tpg)
1560 				continue;
1561 			tmp_tf_ops = tmp_tpg->se_tpg_tfo;
1562 			if (!tmp_tf_ops)
1563 				continue;
1564 			if (!tmp_tf_ops->get_fabric_proto_ident ||
1565 			    !tmp_tf_ops->tpg_parse_pr_out_transport_id)
1566 				continue;
1567 			/*
1568 			 * Look for the matching proto_ident provided by
1569 			 * the received TransportID
1570 			 */
1571 			tmp_proto_ident = tmp_tf_ops->get_fabric_proto_ident(tmp_tpg);
1572 			if (tmp_proto_ident != proto_ident)
1573 				continue;
1574 			dest_rtpi = tmp_port->sep_rtpi;
1575 
1576 			i_str = tmp_tf_ops->tpg_parse_pr_out_transport_id(
1577 					tmp_tpg, (const char *)ptr, &tid_len,
1578 					&iport_ptr);
1579 			if (!i_str)
1580 				continue;
1581 
1582 			atomic_inc(&tmp_tpg->tpg_pr_ref_count);
1583 			smp_mb__after_atomic_inc();
1584 			spin_unlock(&dev->se_port_lock);
1585 
1586 			ret = core_scsi3_tpg_depend_item(tmp_tpg);
1587 			if (ret != 0) {
1588 				pr_err(" core_scsi3_tpg_depend_item()"
1589 					" for tmp_tpg\n");
1590 				atomic_dec(&tmp_tpg->tpg_pr_ref_count);
1591 				smp_mb__after_atomic_dec();
1592 				ret = PYX_TRANSPORT_LU_COMM_FAILURE;
1593 				goto out;
1594 			}
1595 			/*
1596 			 * Locate the desination initiator ACL to be registered
1597 			 * from the decoded fabric module specific TransportID
1598 			 * at *i_str.
1599 			 */
1600 			spin_lock_irq(&tmp_tpg->acl_node_lock);
1601 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1602 						tmp_tpg, i_str);
1603 			if (dest_node_acl) {
1604 				atomic_inc(&dest_node_acl->acl_pr_ref_count);
1605 				smp_mb__after_atomic_inc();
1606 			}
1607 			spin_unlock_irq(&tmp_tpg->acl_node_lock);
1608 
1609 			if (!dest_node_acl) {
1610 				core_scsi3_tpg_undepend_item(tmp_tpg);
1611 				spin_lock(&dev->se_port_lock);
1612 				continue;
1613 			}
1614 
1615 			ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
1616 			if (ret != 0) {
1617 				pr_err("configfs_depend_item() failed"
1618 					" for dest_node_acl->acl_group\n");
1619 				atomic_dec(&dest_node_acl->acl_pr_ref_count);
1620 				smp_mb__after_atomic_dec();
1621 				core_scsi3_tpg_undepend_item(tmp_tpg);
1622 				ret = PYX_TRANSPORT_LU_COMM_FAILURE;
1623 				goto out;
1624 			}
1625 
1626 			dest_tpg = tmp_tpg;
1627 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1628 				" %s Port RTPI: %hu\n",
1629 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1630 				dest_node_acl->initiatorname, dest_rtpi);
1631 
1632 			spin_lock(&dev->se_port_lock);
1633 			break;
1634 		}
1635 		spin_unlock(&dev->se_port_lock);
1636 
1637 		if (!dest_tpg) {
1638 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1639 					" dest_tpg\n");
1640 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1641 			goto out;
1642 		}
1643 #if 0
1644 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1645 			" tid_len: %d for %s + %s\n",
1646 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1647 			tpdl, tid_len, i_str, iport_ptr);
1648 #endif
1649 		if (tid_len > tpdl) {
1650 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1651 				" %u for Transport ID: %s\n", tid_len, ptr);
1652 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1653 			core_scsi3_tpg_undepend_item(dest_tpg);
1654 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1655 			goto out;
1656 		}
1657 		/*
1658 		 * Locate the desintation struct se_dev_entry pointer for matching
1659 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1660 		 * Target Port.
1661 		 */
1662 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1663 					dest_rtpi);
1664 		if (!dest_se_deve) {
1665 			pr_err("Unable to locate %s dest_se_deve"
1666 				" from destination RTPI: %hu\n",
1667 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1668 				dest_rtpi);
1669 
1670 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1671 			core_scsi3_tpg_undepend_item(dest_tpg);
1672 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1673 			goto out;
1674 		}
1675 
1676 		ret = core_scsi3_lunacl_depend_item(dest_se_deve);
1677 		if (ret < 0) {
1678 			pr_err("core_scsi3_lunacl_depend_item()"
1679 					" failed\n");
1680 			atomic_dec(&dest_se_deve->pr_ref_count);
1681 			smp_mb__after_atomic_dec();
1682 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1683 			core_scsi3_tpg_undepend_item(dest_tpg);
1684 			ret = PYX_TRANSPORT_LU_COMM_FAILURE;
1685 			goto out;
1686 		}
1687 #if 0
1688 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1689 			" dest_se_deve mapped_lun: %u\n",
1690 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1691 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1692 #endif
1693 		/*
1694 		 * Skip any TransportIDs that already have a registration for
1695 		 * this target port.
1696 		 */
1697 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1698 					iport_ptr);
1699 		if (pr_reg_e) {
1700 			core_scsi3_put_pr_reg(pr_reg_e);
1701 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1702 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1703 			core_scsi3_tpg_undepend_item(dest_tpg);
1704 			ptr += tid_len;
1705 			tpdl -= tid_len;
1706 			tid_len = 0;
1707 			continue;
1708 		}
1709 		/*
1710 		 * Allocate a struct pr_transport_id_holder and setup
1711 		 * the dest_node_acl and dest_se_deve pointers for the
1712 		 * loop below.
1713 		 */
1714 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1715 				GFP_KERNEL);
1716 		if (!tidh_new) {
1717 			pr_err("Unable to allocate tidh_new\n");
1718 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1719 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1720 			core_scsi3_tpg_undepend_item(dest_tpg);
1721 			ret = PYX_TRANSPORT_LU_COMM_FAILURE;
1722 			goto out;
1723 		}
1724 		INIT_LIST_HEAD(&tidh_new->dest_list);
1725 		tidh_new->dest_tpg = dest_tpg;
1726 		tidh_new->dest_node_acl = dest_node_acl;
1727 		tidh_new->dest_se_deve = dest_se_deve;
1728 
1729 		/*
1730 		 * Allocate, but do NOT add the registration for the
1731 		 * TransportID referenced SCSI Initiator port.  This
1732 		 * done because of the following from spc4r17 in section
1733 		 * 6.14.3 wrt SPEC_I_PT:
1734 		 *
1735 		 * "If a registration fails for any initiator port (e.g., if th
1736 		 * logical unit does not have enough resources available to
1737 		 * hold the registration information), no registrations shall be
1738 		 * made, and the command shall be terminated with
1739 		 * CHECK CONDITION status."
1740 		 *
1741 		 * That means we call __core_scsi3_alloc_registration() here,
1742 		 * and then call __core_scsi3_add_registration() in the
1743 		 * 2nd loop which will never fail.
1744 		 */
1745 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1746 				dest_node_acl, dest_se_deve, iport_ptr,
1747 				sa_res_key, all_tg_pt, aptpl);
1748 		if (!dest_pr_reg) {
1749 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1750 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1751 			core_scsi3_tpg_undepend_item(dest_tpg);
1752 			kfree(tidh_new);
1753 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
1754 			goto out;
1755 		}
1756 		tidh_new->dest_pr_reg = dest_pr_reg;
1757 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1758 
1759 		ptr += tid_len;
1760 		tpdl -= tid_len;
1761 		tid_len = 0;
1762 
1763 	}
1764 
1765 	transport_kunmap_first_data_page(cmd);
1766 
1767 	/*
1768 	 * Go ahead and create a registrations from tid_dest_list for the
1769 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1770 	 * and dest_se_deve.
1771 	 *
1772 	 * The SA Reservation Key from the PROUT is set for the
1773 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1774 	 * means that the TransportID Initiator port will be
1775 	 * registered on all of the target ports in the SCSI target device
1776 	 * ALL_TG_PT=0 means the registration will only be for the
1777 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1778 	 * was received.
1779 	 */
1780 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1781 		dest_tpg = tidh->dest_tpg;
1782 		dest_node_acl = tidh->dest_node_acl;
1783 		dest_se_deve = tidh->dest_se_deve;
1784 		dest_pr_reg = tidh->dest_pr_reg;
1785 		dest_local_nexus = tidh->dest_local_nexus;
1786 
1787 		list_del(&tidh->dest_list);
1788 		kfree(tidh);
1789 
1790 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1791 		prf_isid = core_pr_dump_initiator_port(dest_pr_reg, &i_buf[0],
1792 						PR_REG_ISID_ID_LEN);
1793 
1794 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1795 					dest_pr_reg, 0, 0);
1796 
1797 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1798 			" registered Transport ID for Node: %s%s Mapped LUN:"
1799 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1800 			dest_node_acl->initiatorname, (prf_isid) ?
1801 			&i_buf[0] : "", dest_se_deve->mapped_lun);
1802 
1803 		if (dest_local_nexus)
1804 			continue;
1805 
1806 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1807 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1808 		core_scsi3_tpg_undepend_item(dest_tpg);
1809 	}
1810 
1811 	return 0;
1812 out:
1813 	transport_kunmap_first_data_page(cmd);
1814 	/*
1815 	 * For the failure case, release everything from tid_dest_list
1816 	 * including *dest_pr_reg and the configfs dependances..
1817 	 */
1818 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1819 		dest_tpg = tidh->dest_tpg;
1820 		dest_node_acl = tidh->dest_node_acl;
1821 		dest_se_deve = tidh->dest_se_deve;
1822 		dest_pr_reg = tidh->dest_pr_reg;
1823 		dest_local_nexus = tidh->dest_local_nexus;
1824 
1825 		list_del(&tidh->dest_list);
1826 		kfree(tidh);
1827 		/*
1828 		 * Release any extra ALL_TG_PT=1 registrations for
1829 		 * the SPEC_I_PT=1 case.
1830 		 */
1831 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1832 				&dest_pr_reg->pr_reg_atp_list,
1833 				pr_reg_atp_mem_list) {
1834 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1835 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1836 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1837 		}
1838 
1839 		kfree(dest_pr_reg->pr_aptpl_buf);
1840 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
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 	return ret;
1850 }
1851 
1852 /*
1853  * Called with struct se_device->dev_reservation_lock held
1854  */
1855 static int __core_scsi3_update_aptpl_buf(
1856 	struct se_device *dev,
1857 	unsigned char *buf,
1858 	u32 pr_aptpl_buf_len,
1859 	int clear_aptpl_metadata)
1860 {
1861 	struct se_lun *lun;
1862 	struct se_portal_group *tpg;
1863 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1864 	struct t10_pr_registration *pr_reg;
1865 	unsigned char tmp[512], isid_buf[32];
1866 	ssize_t len = 0;
1867 	int reg_count = 0;
1868 
1869 	memset(buf, 0, pr_aptpl_buf_len);
1870 	/*
1871 	 * Called to clear metadata once APTPL has been deactivated.
1872 	 */
1873 	if (clear_aptpl_metadata) {
1874 		snprintf(buf, pr_aptpl_buf_len,
1875 				"No Registrations or Reservations\n");
1876 		return 0;
1877 	}
1878 	/*
1879 	 * Walk the registration list..
1880 	 */
1881 	spin_lock(&su_dev->t10_pr.registration_lock);
1882 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
1883 			pr_reg_list) {
1884 
1885 		tmp[0] = '\0';
1886 		isid_buf[0] = '\0';
1887 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1888 		lun = pr_reg->pr_reg_tg_pt_lun;
1889 		/*
1890 		 * Write out any ISID value to APTPL metadata that was included
1891 		 * in the original registration.
1892 		 */
1893 		if (pr_reg->isid_present_at_reg)
1894 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1895 					pr_reg->pr_reg_isid);
1896 		/*
1897 		 * Include special metadata if the pr_reg matches the
1898 		 * reservation holder.
1899 		 */
1900 		if (dev->dev_pr_res_holder == pr_reg) {
1901 			snprintf(tmp, 512, "PR_REG_START: %d"
1902 				"\ninitiator_fabric=%s\n"
1903 				"initiator_node=%s\n%s"
1904 				"sa_res_key=%llu\n"
1905 				"res_holder=1\nres_type=%02x\n"
1906 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1907 				"mapped_lun=%u\n", reg_count,
1908 				tpg->se_tpg_tfo->get_fabric_name(),
1909 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1910 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1911 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1912 				pr_reg->pr_res_mapped_lun);
1913 		} else {
1914 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1915 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1916 				"sa_res_key=%llu\nres_holder=0\n"
1917 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1918 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1919 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1920 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1921 				pr_reg->pr_res_mapped_lun);
1922 		}
1923 
1924 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1925 			pr_err("Unable to update renaming"
1926 				" APTPL metadata\n");
1927 			spin_unlock(&su_dev->t10_pr.registration_lock);
1928 			return -EMSGSIZE;
1929 		}
1930 		len += sprintf(buf+len, "%s", tmp);
1931 
1932 		/*
1933 		 * Include information about the associated SCSI target port.
1934 		 */
1935 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1936 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1937 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1938 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1939 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1940 			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);
1941 
1942 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1943 			pr_err("Unable to update renaming"
1944 				" APTPL metadata\n");
1945 			spin_unlock(&su_dev->t10_pr.registration_lock);
1946 			return -EMSGSIZE;
1947 		}
1948 		len += sprintf(buf+len, "%s", tmp);
1949 		reg_count++;
1950 	}
1951 	spin_unlock(&su_dev->t10_pr.registration_lock);
1952 
1953 	if (!reg_count)
1954 		len += sprintf(buf+len, "No Registrations or Reservations");
1955 
1956 	return 0;
1957 }
1958 
1959 static int core_scsi3_update_aptpl_buf(
1960 	struct se_device *dev,
1961 	unsigned char *buf,
1962 	u32 pr_aptpl_buf_len,
1963 	int clear_aptpl_metadata)
1964 {
1965 	int ret;
1966 
1967 	spin_lock(&dev->dev_reservation_lock);
1968 	ret = __core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
1969 				clear_aptpl_metadata);
1970 	spin_unlock(&dev->dev_reservation_lock);
1971 
1972 	return ret;
1973 }
1974 
1975 /*
1976  * Called with struct se_device->aptpl_file_mutex held
1977  */
1978 static int __core_scsi3_write_aptpl_to_file(
1979 	struct se_device *dev,
1980 	unsigned char *buf,
1981 	u32 pr_aptpl_buf_len)
1982 {
1983 	struct t10_wwn *wwn = &dev->se_sub_dev->t10_wwn;
1984 	struct file *file;
1985 	struct iovec iov[1];
1986 	mm_segment_t old_fs;
1987 	int flags = O_RDWR | O_CREAT | O_TRUNC;
1988 	char path[512];
1989 	int ret;
1990 
1991 	memset(iov, 0, sizeof(struct iovec));
1992 	memset(path, 0, 512);
1993 
1994 	if (strlen(&wwn->unit_serial[0]) >= 512) {
1995 		pr_err("WWN value for struct se_device does not fit"
1996 			" into path buffer\n");
1997 		return -EMSGSIZE;
1998 	}
1999 
2000 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
2001 	file = filp_open(path, flags, 0600);
2002 	if (IS_ERR(file) || !file || !file->f_dentry) {
2003 		pr_err("filp_open(%s) for APTPL metadata"
2004 			" failed\n", path);
2005 		return (PTR_ERR(file) < 0 ? PTR_ERR(file) : -ENOENT);
2006 	}
2007 
2008 	iov[0].iov_base = &buf[0];
2009 	if (!pr_aptpl_buf_len)
2010 		iov[0].iov_len = (strlen(&buf[0]) + 1); /* Add extra for NULL */
2011 	else
2012 		iov[0].iov_len = pr_aptpl_buf_len;
2013 
2014 	old_fs = get_fs();
2015 	set_fs(get_ds());
2016 	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
2017 	set_fs(old_fs);
2018 
2019 	if (ret < 0) {
2020 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2021 		filp_close(file, NULL);
2022 		return -EIO;
2023 	}
2024 	filp_close(file, NULL);
2025 
2026 	return 0;
2027 }
2028 
2029 static int core_scsi3_update_and_write_aptpl(
2030 	struct se_device *dev,
2031 	unsigned char *in_buf,
2032 	u32 in_pr_aptpl_buf_len)
2033 {
2034 	unsigned char null_buf[64], *buf;
2035 	u32 pr_aptpl_buf_len;
2036 	int ret, clear_aptpl_metadata = 0;
2037 	/*
2038 	 * Can be called with a NULL pointer from PROUT service action CLEAR
2039 	 */
2040 	if (!in_buf) {
2041 		memset(null_buf, 0, 64);
2042 		buf = &null_buf[0];
2043 		/*
2044 		 * This will clear the APTPL metadata to:
2045 		 * "No Registrations or Reservations" status
2046 		 */
2047 		pr_aptpl_buf_len = 64;
2048 		clear_aptpl_metadata = 1;
2049 	} else {
2050 		buf = in_buf;
2051 		pr_aptpl_buf_len = in_pr_aptpl_buf_len;
2052 	}
2053 
2054 	ret = core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
2055 				clear_aptpl_metadata);
2056 	if (ret != 0)
2057 		return ret;
2058 	/*
2059 	 * __core_scsi3_write_aptpl_to_file() will call strlen()
2060 	 * on the passed buf to determine pr_aptpl_buf_len.
2061 	 */
2062 	ret = __core_scsi3_write_aptpl_to_file(dev, buf, 0);
2063 	if (ret != 0)
2064 		return ret;
2065 
2066 	return ret;
2067 }
2068 
2069 static int core_scsi3_emulate_pro_register(
2070 	struct se_cmd *cmd,
2071 	u64 res_key,
2072 	u64 sa_res_key,
2073 	int aptpl,
2074 	int all_tg_pt,
2075 	int spec_i_pt,
2076 	int ignore_key)
2077 {
2078 	struct se_session *se_sess = cmd->se_sess;
2079 	struct se_device *dev = cmd->se_dev;
2080 	struct se_dev_entry *se_deve;
2081 	struct se_lun *se_lun = cmd->se_lun;
2082 	struct se_portal_group *se_tpg;
2083 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp, *pr_reg_e;
2084 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2085 	/* Used for APTPL metadata w/ UNREGISTER */
2086 	unsigned char *pr_aptpl_buf = NULL;
2087 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2088 	int pr_holder = 0, ret = 0, type;
2089 
2090 	if (!se_sess || !se_lun) {
2091 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2092 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2093 	}
2094 	se_tpg = se_sess->se_tpg;
2095 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2096 
2097 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2098 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2099 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2100 				PR_REG_ISID_LEN);
2101 		isid_ptr = &isid_buf[0];
2102 	}
2103 	/*
2104 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2105 	 */
2106 	pr_reg_e = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2107 	if (!pr_reg_e) {
2108 		if (res_key) {
2109 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2110 				" for SA REGISTER, returning CONFLICT\n");
2111 			return PYX_TRANSPORT_RESERVATION_CONFLICT;
2112 		}
2113 		/*
2114 		 * Do nothing but return GOOD status.
2115 		 */
2116 		if (!sa_res_key)
2117 			return PYX_TRANSPORT_SENT_TO_TRANSPORT;
2118 
2119 		if (!spec_i_pt) {
2120 			/*
2121 			 * Perform the Service Action REGISTER on the Initiator
2122 			 * Port Endpoint that the PRO was received from on the
2123 			 * Logical Unit of the SCSI device server.
2124 			 */
2125 			ret = core_scsi3_alloc_registration(cmd->se_dev,
2126 					se_sess->se_node_acl, se_deve, isid_ptr,
2127 					sa_res_key, all_tg_pt, aptpl,
2128 					ignore_key, 0);
2129 			if (ret != 0) {
2130 				pr_err("Unable to allocate"
2131 					" struct t10_pr_registration\n");
2132 				return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
2133 			}
2134 		} else {
2135 			/*
2136 			 * Register both the Initiator port that received
2137 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2138 			 * TransportID from Parameter list and loop through
2139 			 * fabric dependent parameter list while calling
2140 			 * logic from of core_scsi3_alloc_registration() for
2141 			 * each TransportID provided SCSI Initiator Port/Device
2142 			 */
2143 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2144 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2145 			if (ret != 0)
2146 				return ret;
2147 		}
2148 		/*
2149 		 * Nothing left to do for the APTPL=0 case.
2150 		 */
2151 		if (!aptpl) {
2152 			pr_tmpl->pr_aptpl_active = 0;
2153 			core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2154 			pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
2155 					" REGISTER\n");
2156 			return 0;
2157 		}
2158 		/*
2159 		 * Locate the newly allocated local I_T Nexus *pr_reg, and
2160 		 * update the APTPL metadata information using its
2161 		 * preallocated *pr_reg->pr_aptpl_buf.
2162 		 */
2163 		pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev,
2164 				se_sess->se_node_acl, se_sess);
2165 
2166 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2167 				&pr_reg->pr_aptpl_buf[0],
2168 				pr_tmpl->pr_aptpl_buf_len);
2169 		if (!ret) {
2170 			pr_tmpl->pr_aptpl_active = 1;
2171 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for REGISTER\n");
2172 		}
2173 
2174 		core_scsi3_put_pr_reg(pr_reg);
2175 		return ret;
2176 	} else {
2177 		/*
2178 		 * Locate the existing *pr_reg via struct se_node_acl pointers
2179 		 */
2180 		pr_reg = pr_reg_e;
2181 		type = pr_reg->pr_res_type;
2182 
2183 		if (!ignore_key) {
2184 			if (res_key != pr_reg->pr_res_key) {
2185 				pr_err("SPC-3 PR REGISTER: Received"
2186 					" res_key: 0x%016Lx does not match"
2187 					" existing SA REGISTER res_key:"
2188 					" 0x%016Lx\n", res_key,
2189 					pr_reg->pr_res_key);
2190 				core_scsi3_put_pr_reg(pr_reg);
2191 				return PYX_TRANSPORT_RESERVATION_CONFLICT;
2192 			}
2193 		}
2194 		if (spec_i_pt) {
2195 			pr_err("SPC-3 PR UNREGISTER: SPEC_I_PT"
2196 				" set while sa_res_key=0\n");
2197 			core_scsi3_put_pr_reg(pr_reg);
2198 			return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
2199 		}
2200 		/*
2201 		 * An existing ALL_TG_PT=1 registration being released
2202 		 * must also set ALL_TG_PT=1 in the incoming PROUT.
2203 		 */
2204 		if (pr_reg->pr_reg_all_tg_pt && !(all_tg_pt)) {
2205 			pr_err("SPC-3 PR UNREGISTER: ALL_TG_PT=1"
2206 				" registration exists, but ALL_TG_PT=1 bit not"
2207 				" present in received PROUT\n");
2208 			core_scsi3_put_pr_reg(pr_reg);
2209 			return PYX_TRANSPORT_INVALID_CDB_FIELD;
2210 		}
2211 		/*
2212 		 * Allocate APTPL metadata buffer used for UNREGISTER ops
2213 		 */
2214 		if (aptpl) {
2215 			pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len,
2216 						GFP_KERNEL);
2217 			if (!pr_aptpl_buf) {
2218 				pr_err("Unable to allocate"
2219 					" pr_aptpl_buf\n");
2220 				core_scsi3_put_pr_reg(pr_reg);
2221 				return PYX_TRANSPORT_LU_COMM_FAILURE;
2222 			}
2223 		}
2224 		/*
2225 		 * sa_res_key=0 Unregister Reservation Key for registered I_T
2226 		 * Nexus sa_res_key=1 Change Reservation Key for registered I_T
2227 		 * Nexus.
2228 		 */
2229 		if (!sa_res_key) {
2230 			pr_holder = core_scsi3_check_implict_release(
2231 					cmd->se_dev, pr_reg);
2232 			if (pr_holder < 0) {
2233 				kfree(pr_aptpl_buf);
2234 				core_scsi3_put_pr_reg(pr_reg);
2235 				return PYX_TRANSPORT_RESERVATION_CONFLICT;
2236 			}
2237 
2238 			spin_lock(&pr_tmpl->registration_lock);
2239 			/*
2240 			 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2241 			 * and matching pr_res_key.
2242 			 */
2243 			if (pr_reg->pr_reg_all_tg_pt) {
2244 				list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2245 						&pr_tmpl->registration_list,
2246 						pr_reg_list) {
2247 
2248 					if (!pr_reg_p->pr_reg_all_tg_pt)
2249 						continue;
2250 
2251 					if (pr_reg_p->pr_res_key != res_key)
2252 						continue;
2253 
2254 					if (pr_reg == pr_reg_p)
2255 						continue;
2256 
2257 					if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2258 						   pr_reg_p->pr_reg_nacl->initiatorname))
2259 						continue;
2260 
2261 					__core_scsi3_free_registration(dev,
2262 							pr_reg_p, NULL, 0);
2263 				}
2264 			}
2265 			/*
2266 			 * Release the calling I_T Nexus registration now..
2267 			 */
2268 			__core_scsi3_free_registration(cmd->se_dev, pr_reg,
2269 							NULL, 1);
2270 			/*
2271 			 * From spc4r17, section 5.7.11.3 Unregistering
2272 			 *
2273 			 * If the persistent reservation is a registrants only
2274 			 * type, the device server shall establish a unit
2275 			 * attention condition for the initiator port associated
2276 			 * with every registered I_T nexus except for the I_T
2277 			 * nexus on which the PERSISTENT RESERVE OUT command was
2278 			 * received, with the additional sense code set to
2279 			 * RESERVATIONS RELEASED.
2280 			 */
2281 			if (pr_holder &&
2282 			   ((type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
2283 			    (type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY))) {
2284 				list_for_each_entry(pr_reg_p,
2285 						&pr_tmpl->registration_list,
2286 						pr_reg_list) {
2287 
2288 					core_scsi3_ua_allocate(
2289 						pr_reg_p->pr_reg_nacl,
2290 						pr_reg_p->pr_res_mapped_lun,
2291 						0x2A,
2292 						ASCQ_2AH_RESERVATIONS_RELEASED);
2293 				}
2294 			}
2295 			spin_unlock(&pr_tmpl->registration_lock);
2296 
2297 			if (!aptpl) {
2298 				pr_tmpl->pr_aptpl_active = 0;
2299 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2300 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2301 						" for UNREGISTER\n");
2302 				return 0;
2303 			}
2304 
2305 			ret = core_scsi3_update_and_write_aptpl(dev,
2306 					&pr_aptpl_buf[0],
2307 					pr_tmpl->pr_aptpl_buf_len);
2308 			if (!ret) {
2309 				pr_tmpl->pr_aptpl_active = 1;
2310 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2311 						" for UNREGISTER\n");
2312 			}
2313 
2314 			kfree(pr_aptpl_buf);
2315 			return ret;
2316 		} else {
2317 			/*
2318 			 * Increment PRgeneration counter for struct se_device"
2319 			 * upon a successful REGISTER, see spc4r17 section 6.3.2
2320 			 * READ_KEYS service action.
2321 			 */
2322 			pr_reg->pr_res_generation = core_scsi3_pr_generation(
2323 							cmd->se_dev);
2324 			pr_reg->pr_res_key = sa_res_key;
2325 			pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2326 				" Key for %s to: 0x%016Lx PRgeneration:"
2327 				" 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2328 				(ignore_key) ? "_AND_IGNORE_EXISTING_KEY" : "",
2329 				pr_reg->pr_reg_nacl->initiatorname,
2330 				pr_reg->pr_res_key, pr_reg->pr_res_generation);
2331 
2332 			if (!aptpl) {
2333 				pr_tmpl->pr_aptpl_active = 0;
2334 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2335 				core_scsi3_put_pr_reg(pr_reg);
2336 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2337 						" for REGISTER\n");
2338 				return 0;
2339 			}
2340 
2341 			ret = core_scsi3_update_and_write_aptpl(dev,
2342 					&pr_aptpl_buf[0],
2343 					pr_tmpl->pr_aptpl_buf_len);
2344 			if (!ret) {
2345 				pr_tmpl->pr_aptpl_active = 1;
2346 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2347 						" for REGISTER\n");
2348 			}
2349 
2350 			kfree(pr_aptpl_buf);
2351 			core_scsi3_put_pr_reg(pr_reg);
2352 		}
2353 	}
2354 	return 0;
2355 }
2356 
2357 unsigned char *core_scsi3_pr_dump_type(int type)
2358 {
2359 	switch (type) {
2360 	case PR_TYPE_WRITE_EXCLUSIVE:
2361 		return "Write Exclusive Access";
2362 	case PR_TYPE_EXCLUSIVE_ACCESS:
2363 		return "Exclusive Access";
2364 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2365 		return "Write Exclusive Access, Registrants Only";
2366 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2367 		return "Exclusive Access, Registrants Only";
2368 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2369 		return "Write Exclusive Access, All Registrants";
2370 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2371 		return "Exclusive Access, All Registrants";
2372 	default:
2373 		break;
2374 	}
2375 
2376 	return "Unknown SPC-3 PR Type";
2377 }
2378 
2379 static int core_scsi3_pro_reserve(
2380 	struct se_cmd *cmd,
2381 	struct se_device *dev,
2382 	int type,
2383 	int scope,
2384 	u64 res_key)
2385 {
2386 	struct se_session *se_sess = cmd->se_sess;
2387 	struct se_dev_entry *se_deve;
2388 	struct se_lun *se_lun = cmd->se_lun;
2389 	struct se_portal_group *se_tpg;
2390 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2391 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2392 	char i_buf[PR_REG_ISID_ID_LEN];
2393 	int ret, prf_isid;
2394 
2395 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2396 
2397 	if (!se_sess || !se_lun) {
2398 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2399 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2400 	}
2401 	se_tpg = se_sess->se_tpg;
2402 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2403 	/*
2404 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2405 	 */
2406 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2407 				se_sess);
2408 	if (!pr_reg) {
2409 		pr_err("SPC-3 PR: Unable to locate"
2410 			" PR_REGISTERED *pr_reg for RESERVE\n");
2411 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2412 	}
2413 	/*
2414 	 * From spc4r17 Section 5.7.9: Reserving:
2415 	 *
2416 	 * An application client creates a persistent reservation by issuing
2417 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2418 	 * a registered I_T nexus with the following parameters:
2419 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2420 	 * 	 registered with the logical unit for the I_T nexus; and
2421 	 */
2422 	if (res_key != pr_reg->pr_res_key) {
2423 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2424 			" does not match existing SA REGISTER res_key:"
2425 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2426 		core_scsi3_put_pr_reg(pr_reg);
2427 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2428 	}
2429 	/*
2430 	 * From spc4r17 Section 5.7.9: Reserving:
2431 	 *
2432 	 * From above:
2433 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2434 	 *     being created.
2435 	 *
2436 	 * Only one persistent reservation is allowed at a time per logical unit
2437 	 * and that persistent reservation has a scope of LU_SCOPE.
2438 	 */
2439 	if (scope != PR_SCOPE_LU_SCOPE) {
2440 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2441 		core_scsi3_put_pr_reg(pr_reg);
2442 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
2443 	}
2444 	/*
2445 	 * See if we have an existing PR reservation holder pointer at
2446 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2447 	 * *pr_res_holder.
2448 	 */
2449 	spin_lock(&dev->dev_reservation_lock);
2450 	pr_res_holder = dev->dev_pr_res_holder;
2451 	if ((pr_res_holder)) {
2452 		/*
2453 		 * From spc4r17 Section 5.7.9: Reserving:
2454 		 *
2455 		 * If the device server receives a PERSISTENT RESERVE OUT
2456 		 * command from an I_T nexus other than a persistent reservation
2457 		 * holder (see 5.7.10) that attempts to create a persistent
2458 		 * reservation when a persistent reservation already exists for
2459 		 * the logical unit, then the command shall be completed with
2460 		 * RESERVATION CONFLICT status.
2461 		 */
2462 		if (pr_res_holder != pr_reg) {
2463 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2464 			pr_err("SPC-3 PR: Attempted RESERVE from"
2465 				" [%s]: %s while reservation already held by"
2466 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2467 				cmd->se_tfo->get_fabric_name(),
2468 				se_sess->se_node_acl->initiatorname,
2469 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2470 				pr_res_holder->pr_reg_nacl->initiatorname);
2471 
2472 			spin_unlock(&dev->dev_reservation_lock);
2473 			core_scsi3_put_pr_reg(pr_reg);
2474 			return PYX_TRANSPORT_RESERVATION_CONFLICT;
2475 		}
2476 		/*
2477 		 * From spc4r17 Section 5.7.9: Reserving:
2478 		 *
2479 		 * If a persistent reservation holder attempts to modify the
2480 		 * type or scope of an existing persistent reservation, the
2481 		 * command shall be completed with RESERVATION CONFLICT status.
2482 		 */
2483 		if ((pr_res_holder->pr_res_type != type) ||
2484 		    (pr_res_holder->pr_res_scope != scope)) {
2485 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2486 			pr_err("SPC-3 PR: Attempted RESERVE from"
2487 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2488 				" while reservation already held by [%s]: %s,"
2489 				" returning RESERVATION_CONFLICT\n",
2490 				cmd->se_tfo->get_fabric_name(),
2491 				se_sess->se_node_acl->initiatorname,
2492 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2493 				pr_res_holder->pr_reg_nacl->initiatorname);
2494 
2495 			spin_unlock(&dev->dev_reservation_lock);
2496 			core_scsi3_put_pr_reg(pr_reg);
2497 			return PYX_TRANSPORT_RESERVATION_CONFLICT;
2498 		}
2499 		/*
2500 		 * From spc4r17 Section 5.7.9: Reserving:
2501 		 *
2502 		 * If the device server receives a PERSISTENT RESERVE OUT
2503 		 * command with RESERVE service action where the TYPE field and
2504 		 * the SCOPE field contain the same values as the existing type
2505 		 * and scope from a persistent reservation holder, it shall not
2506 		 * make any change to the existing persistent reservation and
2507 		 * shall completethe command with GOOD status.
2508 		 */
2509 		spin_unlock(&dev->dev_reservation_lock);
2510 		core_scsi3_put_pr_reg(pr_reg);
2511 		return PYX_TRANSPORT_SENT_TO_TRANSPORT;
2512 	}
2513 	/*
2514 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2515 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2516 	 */
2517 	pr_reg->pr_res_scope = scope;
2518 	pr_reg->pr_res_type = type;
2519 	pr_reg->pr_res_holder = 1;
2520 	dev->dev_pr_res_holder = pr_reg;
2521 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2522 				PR_REG_ISID_ID_LEN);
2523 
2524 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2525 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2526 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2527 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2528 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2529 			cmd->se_tfo->get_fabric_name(),
2530 			se_sess->se_node_acl->initiatorname,
2531 			(prf_isid) ? &i_buf[0] : "");
2532 	spin_unlock(&dev->dev_reservation_lock);
2533 
2534 	if (pr_tmpl->pr_aptpl_active) {
2535 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2536 				&pr_reg->pr_aptpl_buf[0],
2537 				pr_tmpl->pr_aptpl_buf_len);
2538 		if (!ret)
2539 			pr_debug("SPC-3 PR: Updated APTPL metadata"
2540 					" for RESERVE\n");
2541 	}
2542 
2543 	core_scsi3_put_pr_reg(pr_reg);
2544 	return 0;
2545 }
2546 
2547 static int core_scsi3_emulate_pro_reserve(
2548 	struct se_cmd *cmd,
2549 	int type,
2550 	int scope,
2551 	u64 res_key)
2552 {
2553 	struct se_device *dev = cmd->se_dev;
2554 	int ret = 0;
2555 
2556 	switch (type) {
2557 	case PR_TYPE_WRITE_EXCLUSIVE:
2558 	case PR_TYPE_EXCLUSIVE_ACCESS:
2559 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2560 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2561 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2562 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2563 		ret = core_scsi3_pro_reserve(cmd, dev, type, scope, res_key);
2564 		break;
2565 	default:
2566 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2567 			" 0x%02x\n", type);
2568 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
2569 	}
2570 
2571 	return ret;
2572 }
2573 
2574 /*
2575  * Called with struct se_device->dev_reservation_lock held.
2576  */
2577 static void __core_scsi3_complete_pro_release(
2578 	struct se_device *dev,
2579 	struct se_node_acl *se_nacl,
2580 	struct t10_pr_registration *pr_reg,
2581 	int explict)
2582 {
2583 	struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2584 	char i_buf[PR_REG_ISID_ID_LEN];
2585 	int prf_isid;
2586 
2587 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2588 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2589 				PR_REG_ISID_ID_LEN);
2590 	/*
2591 	 * Go ahead and release the current PR reservation holder.
2592 	 */
2593 	dev->dev_pr_res_holder = NULL;
2594 
2595 	pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2596 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2597 		tfo->get_fabric_name(), (explict) ? "explict" : "implict",
2598 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
2599 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2600 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2601 		tfo->get_fabric_name(), se_nacl->initiatorname,
2602 		(prf_isid) ? &i_buf[0] : "");
2603 	/*
2604 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2605 	 */
2606 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2607 }
2608 
2609 static int core_scsi3_emulate_pro_release(
2610 	struct se_cmd *cmd,
2611 	int type,
2612 	int scope,
2613 	u64 res_key)
2614 {
2615 	struct se_device *dev = cmd->se_dev;
2616 	struct se_session *se_sess = cmd->se_sess;
2617 	struct se_lun *se_lun = cmd->se_lun;
2618 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2619 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2620 	int ret, all_reg = 0;
2621 
2622 	if (!se_sess || !se_lun) {
2623 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2624 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2625 	}
2626 	/*
2627 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2628 	 */
2629 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2630 	if (!pr_reg) {
2631 		pr_err("SPC-3 PR: Unable to locate"
2632 			" PR_REGISTERED *pr_reg for RELEASE\n");
2633 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2634 	}
2635 	/*
2636 	 * From spc4r17 Section 5.7.11.2 Releasing:
2637 	 *
2638 	 * If there is no persistent reservation or in response to a persistent
2639 	 * reservation release request from a registered I_T nexus that is not a
2640 	 * persistent reservation holder (see 5.7.10), the device server shall
2641 	 * do the following:
2642 	 *
2643 	 *     a) Not release the persistent reservation, if any;
2644 	 *     b) Not remove any registrations; and
2645 	 *     c) Complete the command with GOOD status.
2646 	 */
2647 	spin_lock(&dev->dev_reservation_lock);
2648 	pr_res_holder = dev->dev_pr_res_holder;
2649 	if (!pr_res_holder) {
2650 		/*
2651 		 * No persistent reservation, return GOOD status.
2652 		 */
2653 		spin_unlock(&dev->dev_reservation_lock);
2654 		core_scsi3_put_pr_reg(pr_reg);
2655 		return PYX_TRANSPORT_SENT_TO_TRANSPORT;
2656 	}
2657 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2658 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
2659 		all_reg = 1;
2660 
2661 	if ((all_reg == 0) && (pr_res_holder != pr_reg)) {
2662 		/*
2663 		 * Non 'All Registrants' PR Type cases..
2664 		 * Release request from a registered I_T nexus that is not a
2665 		 * persistent reservation holder. return GOOD status.
2666 		 */
2667 		spin_unlock(&dev->dev_reservation_lock);
2668 		core_scsi3_put_pr_reg(pr_reg);
2669 		return PYX_TRANSPORT_SENT_TO_TRANSPORT;
2670 	}
2671 	/*
2672 	 * From spc4r17 Section 5.7.11.2 Releasing:
2673 	 *
2674 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2675 	 * release a persistent reservation.
2676 	 *
2677 	 * An application client releases the persistent reservation by issuing
2678 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2679 	 * an I_T nexus that is a persistent reservation holder with the
2680 	 * following parameters:
2681 	 *
2682 	 *     a) RESERVATION KEY field set to the value of the reservation key
2683 	 *	  that is registered with the logical unit for the I_T nexus;
2684 	 */
2685 	if (res_key != pr_reg->pr_res_key) {
2686 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2687 			" does not match existing SA REGISTER res_key:"
2688 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2689 		spin_unlock(&dev->dev_reservation_lock);
2690 		core_scsi3_put_pr_reg(pr_reg);
2691 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2692 	}
2693 	/*
2694 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2695 	 *
2696 	 * b) TYPE field and SCOPE field set to match the persistent
2697 	 *    reservation being released.
2698 	 */
2699 	if ((pr_res_holder->pr_res_type != type) ||
2700 	    (pr_res_holder->pr_res_scope != scope)) {
2701 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2702 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2703 			" reservation from [%s]: %s with different TYPE "
2704 			"and/or SCOPE  while reservation already held by"
2705 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2706 			cmd->se_tfo->get_fabric_name(),
2707 			se_sess->se_node_acl->initiatorname,
2708 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2709 			pr_res_holder->pr_reg_nacl->initiatorname);
2710 
2711 		spin_unlock(&dev->dev_reservation_lock);
2712 		core_scsi3_put_pr_reg(pr_reg);
2713 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2714 	}
2715 	/*
2716 	 * In response to a persistent reservation release request from the
2717 	 * persistent reservation holder the device server shall perform a
2718 	 * release by doing the following as an uninterrupted series of actions:
2719 	 * a) Release the persistent reservation;
2720 	 * b) Not remove any registration(s);
2721 	 * c) If the released persistent reservation is a registrants only type
2722 	 * or all registrants type persistent reservation,
2723 	 *    the device server shall establish a unit attention condition for
2724 	 *    the initiator port associated with every regis-
2725 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2726 	 *    RESERVE OUT command with RELEASE service action was received,
2727 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2728 	 * d) If the persistent reservation is of any other type, the device
2729 	 *    server shall not establish a unit attention condition.
2730 	 */
2731 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2732 			pr_reg, 1);
2733 
2734 	spin_unlock(&dev->dev_reservation_lock);
2735 
2736 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2737 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2738 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2739 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2740 		/*
2741 		 * If no UNIT ATTENTION conditions will be established for
2742 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2743 		 * go ahead and check for APTPL=1 update+write below
2744 		 */
2745 		goto write_aptpl;
2746 	}
2747 
2748 	spin_lock(&pr_tmpl->registration_lock);
2749 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2750 			pr_reg_list) {
2751 		/*
2752 		 * Do not establish a UNIT ATTENTION condition
2753 		 * for the calling I_T Nexus
2754 		 */
2755 		if (pr_reg_p == pr_reg)
2756 			continue;
2757 
2758 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2759 				pr_reg_p->pr_res_mapped_lun,
2760 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2761 	}
2762 	spin_unlock(&pr_tmpl->registration_lock);
2763 
2764 write_aptpl:
2765 	if (pr_tmpl->pr_aptpl_active) {
2766 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2767 				&pr_reg->pr_aptpl_buf[0],
2768 				pr_tmpl->pr_aptpl_buf_len);
2769 		if (!ret)
2770 			pr_debug("SPC-3 PR: Updated APTPL metadata for RELEASE\n");
2771 	}
2772 
2773 	core_scsi3_put_pr_reg(pr_reg);
2774 	return 0;
2775 }
2776 
2777 static int core_scsi3_emulate_pro_clear(
2778 	struct se_cmd *cmd,
2779 	u64 res_key)
2780 {
2781 	struct se_device *dev = cmd->se_dev;
2782 	struct se_node_acl *pr_reg_nacl;
2783 	struct se_session *se_sess = cmd->se_sess;
2784 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2785 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2786 	u32 pr_res_mapped_lun = 0;
2787 	int calling_it_nexus = 0;
2788 	/*
2789 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2790 	 */
2791 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2792 			se_sess->se_node_acl, se_sess);
2793 	if (!pr_reg_n) {
2794 		pr_err("SPC-3 PR: Unable to locate"
2795 			" PR_REGISTERED *pr_reg for CLEAR\n");
2796 			return PYX_TRANSPORT_LU_COMM_FAILURE;
2797 	}
2798 	/*
2799 	 * From spc4r17 section 5.7.11.6, Clearing:
2800 	 *
2801 	 * Any application client may release the persistent reservation and
2802 	 * remove all registrations from a device server by issuing a
2803 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2804 	 * registered I_T nexus with the following parameter:
2805 	 *
2806 	 *	a) RESERVATION KEY field set to the value of the reservation key
2807 	 * 	   that is registered with the logical unit for the I_T nexus.
2808 	 */
2809 	if (res_key != pr_reg_n->pr_res_key) {
2810 		pr_err("SPC-3 PR REGISTER: Received"
2811 			" res_key: 0x%016Lx does not match"
2812 			" existing SA REGISTER res_key:"
2813 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2814 		core_scsi3_put_pr_reg(pr_reg_n);
2815 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2816 	}
2817 	/*
2818 	 * a) Release the persistent reservation, if any;
2819 	 */
2820 	spin_lock(&dev->dev_reservation_lock);
2821 	pr_res_holder = dev->dev_pr_res_holder;
2822 	if (pr_res_holder) {
2823 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2824 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2825 			pr_res_holder, 0);
2826 	}
2827 	spin_unlock(&dev->dev_reservation_lock);
2828 	/*
2829 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2830 	 */
2831 	spin_lock(&pr_tmpl->registration_lock);
2832 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2833 			&pr_tmpl->registration_list, pr_reg_list) {
2834 
2835 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2836 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2837 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2838 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2839 					calling_it_nexus);
2840 		/*
2841 		 * e) Establish a unit attention condition for the initiator
2842 		 *    port associated with every registered I_T nexus other
2843 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2844 		 *    command with CLEAR service action was received, with the
2845 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2846 		 */
2847 		if (!calling_it_nexus)
2848 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2849 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2850 	}
2851 	spin_unlock(&pr_tmpl->registration_lock);
2852 
2853 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2854 		cmd->se_tfo->get_fabric_name());
2855 
2856 	if (pr_tmpl->pr_aptpl_active) {
2857 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2858 		pr_debug("SPC-3 PR: Updated APTPL metadata"
2859 				" for CLEAR\n");
2860 	}
2861 
2862 	core_scsi3_pr_generation(dev);
2863 	return 0;
2864 }
2865 
2866 /*
2867  * Called with struct se_device->dev_reservation_lock held.
2868  */
2869 static void __core_scsi3_complete_pro_preempt(
2870 	struct se_device *dev,
2871 	struct t10_pr_registration *pr_reg,
2872 	struct list_head *preempt_and_abort_list,
2873 	int type,
2874 	int scope,
2875 	int abort)
2876 {
2877 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2878 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2879 	char i_buf[PR_REG_ISID_ID_LEN];
2880 	int prf_isid;
2881 
2882 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2883 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2884 				PR_REG_ISID_ID_LEN);
2885 	/*
2886 	 * Do an implict RELEASE of the existing reservation.
2887 	 */
2888 	if (dev->dev_pr_res_holder)
2889 		__core_scsi3_complete_pro_release(dev, nacl,
2890 				dev->dev_pr_res_holder, 0);
2891 
2892 	dev->dev_pr_res_holder = pr_reg;
2893 	pr_reg->pr_res_holder = 1;
2894 	pr_reg->pr_res_type = type;
2895 	pr_reg->pr_res_scope = scope;
2896 
2897 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2898 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2899 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2900 		core_scsi3_pr_dump_type(type),
2901 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2902 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2903 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2904 		nacl->initiatorname, (prf_isid) ? &i_buf[0] : "");
2905 	/*
2906 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2907 	 * struct t10_pr_registration to the list that will be compared
2908 	 * against received CDBs..
2909 	 */
2910 	if (preempt_and_abort_list)
2911 		list_add_tail(&pr_reg->pr_reg_abort_list,
2912 				preempt_and_abort_list);
2913 }
2914 
2915 static void core_scsi3_release_preempt_and_abort(
2916 	struct list_head *preempt_and_abort_list,
2917 	struct t10_pr_registration *pr_reg_holder)
2918 {
2919 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2920 
2921 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2922 				pr_reg_abort_list) {
2923 
2924 		list_del(&pr_reg->pr_reg_abort_list);
2925 		if (pr_reg_holder == pr_reg)
2926 			continue;
2927 		if (pr_reg->pr_res_holder) {
2928 			pr_warn("pr_reg->pr_res_holder still set\n");
2929 			continue;
2930 		}
2931 
2932 		pr_reg->pr_reg_deve = NULL;
2933 		pr_reg->pr_reg_nacl = NULL;
2934 		kfree(pr_reg->pr_aptpl_buf);
2935 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2936 	}
2937 }
2938 
2939 int core_scsi3_check_cdb_abort_and_preempt(
2940 	struct list_head *preempt_and_abort_list,
2941 	struct se_cmd *cmd)
2942 {
2943 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2944 
2945 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2946 				pr_reg_abort_list) {
2947 		if (pr_reg->pr_res_key == cmd->pr_res_key)
2948 			return 0;
2949 	}
2950 
2951 	return 1;
2952 }
2953 
2954 static int core_scsi3_pro_preempt(
2955 	struct se_cmd *cmd,
2956 	int type,
2957 	int scope,
2958 	u64 res_key,
2959 	u64 sa_res_key,
2960 	int abort)
2961 {
2962 	struct se_device *dev = cmd->se_dev;
2963 	struct se_dev_entry *se_deve;
2964 	struct se_node_acl *pr_reg_nacl;
2965 	struct se_session *se_sess = cmd->se_sess;
2966 	struct list_head preempt_and_abort_list;
2967 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2968 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2969 	u32 pr_res_mapped_lun = 0;
2970 	int all_reg = 0, calling_it_nexus = 0, released_regs = 0;
2971 	int prh_type = 0, prh_scope = 0, ret;
2972 
2973 	if (!se_sess)
2974 		return PYX_TRANSPORT_LU_COMM_FAILURE;
2975 
2976 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2977 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2978 				se_sess);
2979 	if (!pr_reg_n) {
2980 		pr_err("SPC-3 PR: Unable to locate"
2981 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
2982 			(abort) ? "_AND_ABORT" : "");
2983 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2984 	}
2985 	if (pr_reg_n->pr_res_key != res_key) {
2986 		core_scsi3_put_pr_reg(pr_reg_n);
2987 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
2988 	}
2989 	if (scope != PR_SCOPE_LU_SCOPE) {
2990 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2991 		core_scsi3_put_pr_reg(pr_reg_n);
2992 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
2993 	}
2994 	INIT_LIST_HEAD(&preempt_and_abort_list);
2995 
2996 	spin_lock(&dev->dev_reservation_lock);
2997 	pr_res_holder = dev->dev_pr_res_holder;
2998 	if (pr_res_holder &&
2999 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3000 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
3001 		all_reg = 1;
3002 
3003 	if (!all_reg && !sa_res_key) {
3004 		spin_unlock(&dev->dev_reservation_lock);
3005 		core_scsi3_put_pr_reg(pr_reg_n);
3006 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3007 	}
3008 	/*
3009 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
3010 	 *
3011 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
3012 	 * persistent reservation holder or there is no persistent reservation
3013 	 * holder (i.e., there is no persistent reservation), then the device
3014 	 * server shall perform a preempt by doing the following in an
3015 	 * uninterrupted series of actions. (See below..)
3016 	 */
3017 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
3018 		/*
3019 		 * No existing or SA Reservation Key matching reservations..
3020 		 *
3021 		 * PROUT SA PREEMPT with All Registrant type reservations are
3022 		 * allowed to be processed without a matching SA Reservation Key
3023 		 */
3024 		spin_lock(&pr_tmpl->registration_lock);
3025 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3026 				&pr_tmpl->registration_list, pr_reg_list) {
3027 			/*
3028 			 * Removing of registrations in non all registrants
3029 			 * type reservations without a matching SA reservation
3030 			 * key.
3031 			 *
3032 			 * a) Remove the registrations for all I_T nexuses
3033 			 *    specified by the SERVICE ACTION RESERVATION KEY
3034 			 *    field;
3035 			 * b) Ignore the contents of the SCOPE and TYPE fields;
3036 			 * c) Process tasks as defined in 5.7.1; and
3037 			 * d) Establish a unit attention condition for the
3038 			 *    initiator port associated with every I_T nexus
3039 			 *    that lost its registration other than the I_T
3040 			 *    nexus on which the PERSISTENT RESERVE OUT command
3041 			 *    was received, with the additional sense code set
3042 			 *    to REGISTRATIONS PREEMPTED.
3043 			 */
3044 			if (!all_reg) {
3045 				if (pr_reg->pr_res_key != sa_res_key)
3046 					continue;
3047 
3048 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3049 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3050 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3051 				__core_scsi3_free_registration(dev, pr_reg,
3052 					(abort) ? &preempt_and_abort_list :
3053 						NULL, calling_it_nexus);
3054 				released_regs++;
3055 			} else {
3056 				/*
3057 				 * Case for any existing all registrants type
3058 				 * reservation, follow logic in spc4r17 section
3059 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
3060 				 *
3061 				 * For a ZERO SA Reservation key, release
3062 				 * all other registrations and do an implict
3063 				 * release of active persistent reservation.
3064 				 *
3065 				 * For a non-ZERO SA Reservation key, only
3066 				 * release the matching reservation key from
3067 				 * registrations.
3068 				 */
3069 				if ((sa_res_key) &&
3070 				     (pr_reg->pr_res_key != sa_res_key))
3071 					continue;
3072 
3073 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3074 				if (calling_it_nexus)
3075 					continue;
3076 
3077 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3078 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3079 				__core_scsi3_free_registration(dev, pr_reg,
3080 					(abort) ? &preempt_and_abort_list :
3081 						NULL, 0);
3082 				released_regs++;
3083 			}
3084 			if (!calling_it_nexus)
3085 				core_scsi3_ua_allocate(pr_reg_nacl,
3086 					pr_res_mapped_lun, 0x2A,
3087 					ASCQ_2AH_RESERVATIONS_PREEMPTED);
3088 		}
3089 		spin_unlock(&pr_tmpl->registration_lock);
3090 		/*
3091 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
3092 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
3093 		 * RESERVATION KEY field to a value that does not match any
3094 		 * registered reservation key, then the device server shall
3095 		 * complete the command with RESERVATION CONFLICT status.
3096 		 */
3097 		if (!released_regs) {
3098 			spin_unlock(&dev->dev_reservation_lock);
3099 			core_scsi3_put_pr_reg(pr_reg_n);
3100 			return PYX_TRANSPORT_RESERVATION_CONFLICT;
3101 		}
3102 		/*
3103 		 * For an existing all registrants type reservation
3104 		 * with a zero SA rservation key, preempt the existing
3105 		 * reservation with the new PR type and scope.
3106 		 */
3107 		if (pr_res_holder && all_reg && !(sa_res_key)) {
3108 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3109 				(abort) ? &preempt_and_abort_list : NULL,
3110 				type, scope, abort);
3111 
3112 			if (abort)
3113 				core_scsi3_release_preempt_and_abort(
3114 					&preempt_and_abort_list, pr_reg_n);
3115 		}
3116 		spin_unlock(&dev->dev_reservation_lock);
3117 
3118 		if (pr_tmpl->pr_aptpl_active) {
3119 			ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3120 					&pr_reg_n->pr_aptpl_buf[0],
3121 					pr_tmpl->pr_aptpl_buf_len);
3122 			if (!ret)
3123 				pr_debug("SPC-3 PR: Updated APTPL"
3124 					" metadata for  PREEMPT%s\n", (abort) ?
3125 					"_AND_ABORT" : "");
3126 		}
3127 
3128 		core_scsi3_put_pr_reg(pr_reg_n);
3129 		core_scsi3_pr_generation(cmd->se_dev);
3130 		return 0;
3131 	}
3132 	/*
3133 	 * The PREEMPTing SA reservation key matches that of the
3134 	 * existing persistent reservation, first, we check if
3135 	 * we are preempting our own reservation.
3136 	 * From spc4r17, section 5.7.11.4.3 Preempting
3137 	 * persistent reservations and registration handling
3138 	 *
3139 	 * If an all registrants persistent reservation is not
3140 	 * present, it is not an error for the persistent
3141 	 * reservation holder to preempt itself (i.e., a
3142 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3143 	 * or a PREEMPT AND ABORT service action with the
3144 	 * SERVICE ACTION RESERVATION KEY value equal to the
3145 	 * persistent reservation holder's reservation key that
3146 	 * is received from the persistent reservation holder).
3147 	 * In that case, the device server shall establish the
3148 	 * new persistent reservation and maintain the
3149 	 * registration.
3150 	 */
3151 	prh_type = pr_res_holder->pr_res_type;
3152 	prh_scope = pr_res_holder->pr_res_scope;
3153 	/*
3154 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3155 	 * persistent reservation holder (see 5.7.10), the device
3156 	 * server shall perform a preempt by doing the following as
3157 	 * an uninterrupted series of actions:
3158 	 *
3159 	 * a) Release the persistent reservation for the holder
3160 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3161 	 */
3162 	if (pr_reg_n != pr_res_holder)
3163 		__core_scsi3_complete_pro_release(dev,
3164 				pr_res_holder->pr_reg_nacl,
3165 				dev->dev_pr_res_holder, 0);
3166 	/*
3167 	 * b) Remove the registrations for all I_T nexuses identified
3168 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3169 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3170 	 *    OUT command. If an all registrants persistent reservation
3171 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3172 	 *    is set to zero, then all registrations shall be removed
3173 	 *    except for that of the I_T nexus that is being used for
3174 	 *    the PERSISTENT RESERVE OUT command;
3175 	 */
3176 	spin_lock(&pr_tmpl->registration_lock);
3177 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3178 			&pr_tmpl->registration_list, pr_reg_list) {
3179 
3180 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3181 		if (calling_it_nexus)
3182 			continue;
3183 
3184 		if (pr_reg->pr_res_key != sa_res_key)
3185 			continue;
3186 
3187 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3188 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3189 		__core_scsi3_free_registration(dev, pr_reg,
3190 				(abort) ? &preempt_and_abort_list : NULL,
3191 				calling_it_nexus);
3192 		/*
3193 		 * e) Establish a unit attention condition for the initiator
3194 		 *    port associated with every I_T nexus that lost its
3195 		 *    persistent reservation and/or registration, with the
3196 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3197 		 */
3198 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3199 				ASCQ_2AH_RESERVATIONS_PREEMPTED);
3200 	}
3201 	spin_unlock(&pr_tmpl->registration_lock);
3202 	/*
3203 	 * c) Establish a persistent reservation for the preempting
3204 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3205 	 */
3206 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3207 			(abort) ? &preempt_and_abort_list : NULL,
3208 			type, scope, abort);
3209 	/*
3210 	 * d) Process tasks as defined in 5.7.1;
3211 	 * e) See above..
3212 	 * f) If the type or scope has changed, then for every I_T nexus
3213 	 *    whose reservation key was not removed, except for the I_T
3214 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3215 	 *    received, the device server shall establish a unit
3216 	 *    attention condition for the initiator port associated with
3217 	 *    that I_T nexus, with the additional sense code set to
3218 	 *    RESERVATIONS RELEASED. If the type or scope have not
3219 	 *    changed, then no unit attention condition(s) shall be
3220 	 *    established for this reason.
3221 	 */
3222 	if ((prh_type != type) || (prh_scope != scope)) {
3223 		spin_lock(&pr_tmpl->registration_lock);
3224 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3225 				&pr_tmpl->registration_list, pr_reg_list) {
3226 
3227 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3228 			if (calling_it_nexus)
3229 				continue;
3230 
3231 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
3232 					pr_reg->pr_res_mapped_lun, 0x2A,
3233 					ASCQ_2AH_RESERVATIONS_RELEASED);
3234 		}
3235 		spin_unlock(&pr_tmpl->registration_lock);
3236 	}
3237 	spin_unlock(&dev->dev_reservation_lock);
3238 	/*
3239 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3240 	 * All received CDBs for the matching existing reservation and
3241 	 * registrations undergo ABORT_TASK logic.
3242 	 *
3243 	 * From there, core_scsi3_release_preempt_and_abort() will
3244 	 * release every registration in the list (which have already
3245 	 * been removed from the primary pr_reg list), except the
3246 	 * new persistent reservation holder, the calling Initiator Port.
3247 	 */
3248 	if (abort) {
3249 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3250 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3251 						pr_reg_n);
3252 	}
3253 
3254 	if (pr_tmpl->pr_aptpl_active) {
3255 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3256 				&pr_reg_n->pr_aptpl_buf[0],
3257 				pr_tmpl->pr_aptpl_buf_len);
3258 		if (!ret)
3259 			pr_debug("SPC-3 PR: Updated APTPL metadata for PREEMPT"
3260 				"%s\n", (abort) ? "_AND_ABORT" : "");
3261 	}
3262 
3263 	core_scsi3_put_pr_reg(pr_reg_n);
3264 	core_scsi3_pr_generation(cmd->se_dev);
3265 	return 0;
3266 }
3267 
3268 static int core_scsi3_emulate_pro_preempt(
3269 	struct se_cmd *cmd,
3270 	int type,
3271 	int scope,
3272 	u64 res_key,
3273 	u64 sa_res_key,
3274 	int abort)
3275 {
3276 	int ret = 0;
3277 
3278 	switch (type) {
3279 	case PR_TYPE_WRITE_EXCLUSIVE:
3280 	case PR_TYPE_EXCLUSIVE_ACCESS:
3281 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3282 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3283 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3284 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3285 		ret = core_scsi3_pro_preempt(cmd, type, scope,
3286 				res_key, sa_res_key, abort);
3287 		break;
3288 	default:
3289 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3290 			" Type: 0x%02x\n", (abort) ? "_AND_ABORT" : "", type);
3291 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
3292 	}
3293 
3294 	return ret;
3295 }
3296 
3297 
3298 static int core_scsi3_emulate_pro_register_and_move(
3299 	struct se_cmd *cmd,
3300 	u64 res_key,
3301 	u64 sa_res_key,
3302 	int aptpl,
3303 	int unreg)
3304 {
3305 	struct se_session *se_sess = cmd->se_sess;
3306 	struct se_device *dev = cmd->se_dev;
3307 	struct se_dev_entry *se_deve, *dest_se_deve = NULL;
3308 	struct se_lun *se_lun = cmd->se_lun;
3309 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3310 	struct se_port *se_port;
3311 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3312 	struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3313 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3314 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3315 	unsigned char *buf;
3316 	unsigned char *initiator_str;
3317 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
3318 	u32 tid_len, tmp_tid_len;
3319 	int new_reg = 0, type, scope, ret, matching_iname, prf_isid;
3320 	unsigned short rtpi;
3321 	unsigned char proto_ident;
3322 
3323 	if (!se_sess || !se_lun) {
3324 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3325 		return PYX_TRANSPORT_LU_COMM_FAILURE;
3326 	}
3327 	memset(dest_iport, 0, 64);
3328 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3329 	se_tpg = se_sess->se_tpg;
3330 	tf_ops = se_tpg->se_tpg_tfo;
3331 	se_deve = &se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
3332 	/*
3333 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3334 	 *	Register behaviors for a REGISTER AND MOVE service action
3335 	 *
3336 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3337 	 */
3338 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3339 				se_sess);
3340 	if (!pr_reg) {
3341 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3342 			" *pr_reg for REGISTER_AND_MOVE\n");
3343 		return PYX_TRANSPORT_LU_COMM_FAILURE;
3344 	}
3345 	/*
3346 	 * The provided reservation key much match the existing reservation key
3347 	 * provided during this initiator's I_T nexus registration.
3348 	 */
3349 	if (res_key != pr_reg->pr_res_key) {
3350 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3351 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3352 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3353 		core_scsi3_put_pr_reg(pr_reg);
3354 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
3355 	}
3356 	/*
3357 	 * The service active reservation key needs to be non zero
3358 	 */
3359 	if (!sa_res_key) {
3360 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3361 			" sa_res_key\n");
3362 		core_scsi3_put_pr_reg(pr_reg);
3363 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3364 	}
3365 
3366 	/*
3367 	 * Determine the Relative Target Port Identifier where the reservation
3368 	 * will be moved to for the TransportID containing SCSI initiator WWN
3369 	 * information.
3370 	 */
3371 	buf = transport_kmap_first_data_page(cmd);
3372 	rtpi = (buf[18] & 0xff) << 8;
3373 	rtpi |= buf[19] & 0xff;
3374 	tid_len = (buf[20] & 0xff) << 24;
3375 	tid_len |= (buf[21] & 0xff) << 16;
3376 	tid_len |= (buf[22] & 0xff) << 8;
3377 	tid_len |= buf[23] & 0xff;
3378 	transport_kunmap_first_data_page(cmd);
3379 	buf = NULL;
3380 
3381 	if ((tid_len + 24) != cmd->data_length) {
3382 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3383 			" does not equal CDB data_length: %u\n", tid_len,
3384 			cmd->data_length);
3385 		core_scsi3_put_pr_reg(pr_reg);
3386 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3387 	}
3388 
3389 	spin_lock(&dev->se_port_lock);
3390 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3391 		if (se_port->sep_rtpi != rtpi)
3392 			continue;
3393 		dest_se_tpg = se_port->sep_tpg;
3394 		if (!dest_se_tpg)
3395 			continue;
3396 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3397 		if (!dest_tf_ops)
3398 			continue;
3399 
3400 		atomic_inc(&dest_se_tpg->tpg_pr_ref_count);
3401 		smp_mb__after_atomic_inc();
3402 		spin_unlock(&dev->se_port_lock);
3403 
3404 		ret = core_scsi3_tpg_depend_item(dest_se_tpg);
3405 		if (ret != 0) {
3406 			pr_err("core_scsi3_tpg_depend_item() failed"
3407 				" for dest_se_tpg\n");
3408 			atomic_dec(&dest_se_tpg->tpg_pr_ref_count);
3409 			smp_mb__after_atomic_dec();
3410 			core_scsi3_put_pr_reg(pr_reg);
3411 			return PYX_TRANSPORT_LU_COMM_FAILURE;
3412 		}
3413 
3414 		spin_lock(&dev->se_port_lock);
3415 		break;
3416 	}
3417 	spin_unlock(&dev->se_port_lock);
3418 
3419 	if (!dest_se_tpg || !dest_tf_ops) {
3420 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3421 			" fabric ops from Relative Target Port Identifier:"
3422 			" %hu\n", rtpi);
3423 		core_scsi3_put_pr_reg(pr_reg);
3424 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3425 	}
3426 
3427 	buf = transport_kmap_first_data_page(cmd);
3428 	proto_ident = (buf[24] & 0x0f);
3429 #if 0
3430 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3431 			" 0x%02x\n", proto_ident);
3432 #endif
3433 	if (proto_ident != dest_tf_ops->get_fabric_proto_ident(dest_se_tpg)) {
3434 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3435 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3436 			" from fabric: %s\n", proto_ident,
3437 			dest_tf_ops->get_fabric_proto_ident(dest_se_tpg),
3438 			dest_tf_ops->get_fabric_name());
3439 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3440 		goto out;
3441 	}
3442 	if (dest_tf_ops->tpg_parse_pr_out_transport_id == NULL) {
3443 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Fabric does not"
3444 			" containg a valid tpg_parse_pr_out_transport_id"
3445 			" function pointer\n");
3446 		ret = PYX_TRANSPORT_LU_COMM_FAILURE;
3447 		goto out;
3448 	}
3449 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(dest_se_tpg,
3450 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3451 	if (!initiator_str) {
3452 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3453 			" initiator_str from Transport ID\n");
3454 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3455 		goto out;
3456 	}
3457 
3458 	transport_kunmap_first_data_page(cmd);
3459 	buf = NULL;
3460 
3461 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3462 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3463 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3464 		iport_ptr : "");
3465 	/*
3466 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3467 	 * action specifies a TransportID that is the same as the initiator port
3468 	 * of the I_T nexus for the command received, then the command shall
3469 	 * be terminated with CHECK CONDITION status, with the sense key set to
3470 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3471 	 * IN PARAMETER LIST.
3472 	 */
3473 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3474 	matching_iname = (!strcmp(initiator_str,
3475 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3476 	if (!matching_iname)
3477 		goto after_iport_check;
3478 
3479 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3480 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3481 			" matches: %s on received I_T Nexus\n", initiator_str,
3482 			pr_reg_nacl->initiatorname);
3483 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3484 		goto out;
3485 	}
3486 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3487 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3488 			" matches: %s %s on received I_T Nexus\n",
3489 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3490 			pr_reg->pr_reg_isid);
3491 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3492 		goto out;
3493 	}
3494 after_iport_check:
3495 	/*
3496 	 * Locate the destination struct se_node_acl from the received Transport ID
3497 	 */
3498 	spin_lock_irq(&dest_se_tpg->acl_node_lock);
3499 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3500 				initiator_str);
3501 	if (dest_node_acl) {
3502 		atomic_inc(&dest_node_acl->acl_pr_ref_count);
3503 		smp_mb__after_atomic_inc();
3504 	}
3505 	spin_unlock_irq(&dest_se_tpg->acl_node_lock);
3506 
3507 	if (!dest_node_acl) {
3508 		pr_err("Unable to locate %s dest_node_acl for"
3509 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3510 			initiator_str);
3511 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3512 		goto out;
3513 	}
3514 	ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
3515 	if (ret != 0) {
3516 		pr_err("core_scsi3_nodeacl_depend_item() for"
3517 			" dest_node_acl\n");
3518 		atomic_dec(&dest_node_acl->acl_pr_ref_count);
3519 		smp_mb__after_atomic_dec();
3520 		dest_node_acl = NULL;
3521 		ret = PYX_TRANSPORT_LU_COMM_FAILURE;
3522 		goto out;
3523 	}
3524 #if 0
3525 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3526 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3527 		dest_node_acl->initiatorname);
3528 #endif
3529 	/*
3530 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3531 	 * PORT IDENTIFIER.
3532 	 */
3533 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3534 	if (!dest_se_deve) {
3535 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3536 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3537 		ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3538 		goto out;
3539 	}
3540 
3541 	ret = core_scsi3_lunacl_depend_item(dest_se_deve);
3542 	if (ret < 0) {
3543 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3544 		atomic_dec(&dest_se_deve->pr_ref_count);
3545 		smp_mb__after_atomic_dec();
3546 		dest_se_deve = NULL;
3547 		ret = PYX_TRANSPORT_LU_COMM_FAILURE;
3548 		goto out;
3549 	}
3550 #if 0
3551 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3552 		" ACL for dest_se_deve->mapped_lun: %u\n",
3553 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3554 		dest_se_deve->mapped_lun);
3555 #endif
3556 	/*
3557 	 * A persistent reservation needs to already existing in order to
3558 	 * successfully complete the REGISTER_AND_MOVE service action..
3559 	 */
3560 	spin_lock(&dev->dev_reservation_lock);
3561 	pr_res_holder = dev->dev_pr_res_holder;
3562 	if (!pr_res_holder) {
3563 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3564 			" currently held\n");
3565 		spin_unlock(&dev->dev_reservation_lock);
3566 		ret = PYX_TRANSPORT_INVALID_CDB_FIELD;
3567 		goto out;
3568 	}
3569 	/*
3570 	 * The received on I_T Nexus must be the reservation holder.
3571 	 *
3572 	 * From spc4r17 section 5.7.8  Table 50 --
3573 	 * 	Register behaviors for a REGISTER AND MOVE service action
3574 	 */
3575 	if (pr_res_holder != pr_reg) {
3576 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3577 			" Nexus is not reservation holder\n");
3578 		spin_unlock(&dev->dev_reservation_lock);
3579 		ret = PYX_TRANSPORT_RESERVATION_CONFLICT;
3580 		goto out;
3581 	}
3582 	/*
3583 	 * From spc4r17 section 5.7.8: registering and moving reservation
3584 	 *
3585 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3586 	 * action is received and the established persistent reservation is a
3587 	 * Write Exclusive - All Registrants type or Exclusive Access -
3588 	 * All Registrants type reservation, then the command shall be completed
3589 	 * with RESERVATION CONFLICT status.
3590 	 */
3591 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3592 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3593 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3594 			" reservation for type: %s\n",
3595 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3596 		spin_unlock(&dev->dev_reservation_lock);
3597 		ret = PYX_TRANSPORT_RESERVATION_CONFLICT;
3598 		goto out;
3599 	}
3600 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3601 	/*
3602 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3603 	 */
3604 	type = pr_res_holder->pr_res_type;
3605 	scope = pr_res_holder->pr_res_type;
3606 	/*
3607 	 * c) Associate the reservation key specified in the SERVICE ACTION
3608 	 *    RESERVATION KEY field with the I_T nexus specified as the
3609 	 *    destination of the register and move, where:
3610 	 *    A) The I_T nexus is specified by the TransportID and the
3611 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3612 	 *    B) Regardless of the TransportID format used, the association for
3613 	 *       the initiator port is based on either the initiator port name
3614 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3615 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3616 	 *       transport protocols where port names are not required;
3617 	 * d) Register the reservation key specified in the SERVICE ACTION
3618 	 *    RESERVATION KEY field;
3619 	 * e) Retain the reservation key specified in the SERVICE ACTION
3620 	 *    RESERVATION KEY field and associated information;
3621 	 *
3622 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3623 	 * register an I_T nexus that is already registered with the same
3624 	 * reservation key or a different reservation key.
3625 	 */
3626 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3627 					iport_ptr);
3628 	if (!dest_pr_reg) {
3629 		ret = core_scsi3_alloc_registration(cmd->se_dev,
3630 				dest_node_acl, dest_se_deve, iport_ptr,
3631 				sa_res_key, 0, aptpl, 2, 1);
3632 		if (ret != 0) {
3633 			spin_unlock(&dev->dev_reservation_lock);
3634 			ret = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3635 			goto out;
3636 		}
3637 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3638 						iport_ptr);
3639 		new_reg = 1;
3640 	}
3641 	/*
3642 	 * f) Release the persistent reservation for the persistent reservation
3643 	 *    holder (i.e., the I_T nexus on which the
3644 	 */
3645 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3646 			dev->dev_pr_res_holder, 0);
3647 	/*
3648 	 * g) Move the persistent reservation to the specified I_T nexus using
3649 	 *    the same scope and type as the persistent reservation released in
3650 	 *    item f); and
3651 	 */
3652 	dev->dev_pr_res_holder = dest_pr_reg;
3653 	dest_pr_reg->pr_res_holder = 1;
3654 	dest_pr_reg->pr_res_type = type;
3655 	pr_reg->pr_res_scope = scope;
3656 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
3657 				PR_REG_ISID_ID_LEN);
3658 	/*
3659 	 * Increment PRGeneration for existing registrations..
3660 	 */
3661 	if (!new_reg)
3662 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3663 	spin_unlock(&dev->dev_reservation_lock);
3664 
3665 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3666 		" created new reservation holder TYPE: %s on object RTPI:"
3667 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3668 		core_scsi3_pr_dump_type(type), rtpi,
3669 		dest_pr_reg->pr_res_generation);
3670 	pr_debug("SPC-3 PR Successfully moved reservation from"
3671 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3672 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3673 		(prf_isid) ? &i_buf[0] : "", dest_tf_ops->get_fabric_name(),
3674 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3675 		iport_ptr : "");
3676 	/*
3677 	 * It is now safe to release configfs group dependencies for destination
3678 	 * of Transport ID Initiator Device/Port Identifier
3679 	 */
3680 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3681 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3682 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3683 	/*
3684 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3685 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3686 	 */
3687 	if (unreg) {
3688 		spin_lock(&pr_tmpl->registration_lock);
3689 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3690 		spin_unlock(&pr_tmpl->registration_lock);
3691 	} else
3692 		core_scsi3_put_pr_reg(pr_reg);
3693 
3694 	/*
3695 	 * Clear the APTPL metadata if APTPL has been disabled, otherwise
3696 	 * write out the updated metadata to struct file for this SCSI device.
3697 	 */
3698 	if (!aptpl) {
3699 		pr_tmpl->pr_aptpl_active = 0;
3700 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
3701 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
3702 				" REGISTER_AND_MOVE\n");
3703 	} else {
3704 		pr_tmpl->pr_aptpl_active = 1;
3705 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3706 				&dest_pr_reg->pr_aptpl_buf[0],
3707 				pr_tmpl->pr_aptpl_buf_len);
3708 		if (!ret)
3709 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for"
3710 					" REGISTER_AND_MOVE\n");
3711 	}
3712 
3713 	transport_kunmap_first_data_page(cmd);
3714 
3715 	core_scsi3_put_pr_reg(dest_pr_reg);
3716 	return 0;
3717 out:
3718 	if (buf)
3719 		transport_kunmap_first_data_page(cmd);
3720 	if (dest_se_deve)
3721 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3722 	if (dest_node_acl)
3723 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3724 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3725 	core_scsi3_put_pr_reg(pr_reg);
3726 	return ret;
3727 }
3728 
3729 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3730 {
3731 	unsigned int __v1, __v2;
3732 
3733 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3734 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3735 
3736 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3737 }
3738 
3739 /*
3740  * See spc4r17 section 6.14 Table 170
3741  */
3742 static int core_scsi3_emulate_pr_out(struct se_cmd *cmd, unsigned char *cdb)
3743 {
3744 	unsigned char *buf;
3745 	u64 res_key, sa_res_key;
3746 	int sa, scope, type, aptpl;
3747 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3748 	/*
3749 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3750 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3751 	 */
3752 	if (!cmd->se_sess)
3753 		return PYX_TRANSPORT_LU_COMM_FAILURE;
3754 
3755 	if (cmd->data_length < 24) {
3756 		pr_warn("SPC-PR: Received PR OUT parameter list"
3757 			" length too small: %u\n", cmd->data_length);
3758 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3759 	}
3760 	/*
3761 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3762 	 */
3763 	sa = (cdb[1] & 0x1f);
3764 	scope = (cdb[2] & 0xf0);
3765 	type = (cdb[2] & 0x0f);
3766 
3767 	buf = transport_kmap_first_data_page(cmd);
3768 	/*
3769 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3770 	 */
3771 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3772 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3773 	/*
3774 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3775 	 * SCSI TransportIDs.
3776 	 */
3777 	if (sa != PRO_REGISTER_AND_MOVE) {
3778 		spec_i_pt = (buf[20] & 0x08);
3779 		all_tg_pt = (buf[20] & 0x04);
3780 		aptpl = (buf[20] & 0x01);
3781 	} else {
3782 		aptpl = (buf[17] & 0x01);
3783 		unreg = (buf[17] & 0x02);
3784 	}
3785 	transport_kunmap_first_data_page(cmd);
3786 	buf = NULL;
3787 
3788 	/*
3789 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3790 	 */
3791 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER))
3792 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3793 	/*
3794 	 * From spc4r17 section 6.14:
3795 	 *
3796 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3797 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3798 	 * the command shall be terminated with CHECK CONDITION status, with
3799 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3800 	 * code set to PARAMETER LIST LENGTH ERROR.
3801 	 */
3802 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3803 	    (cmd->data_length != 24)) {
3804 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3805 			" list length: %u\n", cmd->data_length);
3806 		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
3807 	}
3808 	/*
3809 	 * (core_scsi3_emulate_pro_* function parameters
3810 	 * are defined by spc4r17 Table 174:
3811 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3812 	 */
3813 	switch (sa) {
3814 	case PRO_REGISTER:
3815 		return core_scsi3_emulate_pro_register(cmd,
3816 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 0);
3817 	case PRO_RESERVE:
3818 		return core_scsi3_emulate_pro_reserve(cmd,
3819 			type, scope, res_key);
3820 	case PRO_RELEASE:
3821 		return core_scsi3_emulate_pro_release(cmd,
3822 			type, scope, res_key);
3823 	case PRO_CLEAR:
3824 		return core_scsi3_emulate_pro_clear(cmd, res_key);
3825 	case PRO_PREEMPT:
3826 		return core_scsi3_emulate_pro_preempt(cmd, type, scope,
3827 					res_key, sa_res_key, 0);
3828 	case PRO_PREEMPT_AND_ABORT:
3829 		return core_scsi3_emulate_pro_preempt(cmd, type, scope,
3830 					res_key, sa_res_key, 1);
3831 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3832 		return core_scsi3_emulate_pro_register(cmd,
3833 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 1);
3834 	case PRO_REGISTER_AND_MOVE:
3835 		return core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3836 				sa_res_key, aptpl, unreg);
3837 	default:
3838 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3839 			" action: 0x%02x\n", cdb[1] & 0x1f);
3840 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
3841 	}
3842 
3843 	return PYX_TRANSPORT_INVALID_CDB_FIELD;
3844 }
3845 
3846 /*
3847  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3848  *
3849  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3850  */
3851 static int core_scsi3_pri_read_keys(struct se_cmd *cmd)
3852 {
3853 	struct se_device *se_dev = cmd->se_dev;
3854 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
3855 	struct t10_pr_registration *pr_reg;
3856 	unsigned char *buf;
3857 	u32 add_len = 0, off = 8;
3858 
3859 	if (cmd->data_length < 8) {
3860 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3861 			" too small\n", cmd->data_length);
3862 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
3863 	}
3864 
3865 	buf = transport_kmap_first_data_page(cmd);
3866 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
3867 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
3868 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
3869 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
3870 
3871 	spin_lock(&su_dev->t10_pr.registration_lock);
3872 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
3873 			pr_reg_list) {
3874 		/*
3875 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3876 		 * next reservation key list descriptor.
3877 		 */
3878 		if ((add_len + 8) > (cmd->data_length - 8))
3879 			break;
3880 
3881 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3882 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3883 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3884 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3885 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3886 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3887 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3888 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3889 
3890 		add_len += 8;
3891 	}
3892 	spin_unlock(&su_dev->t10_pr.registration_lock);
3893 
3894 	buf[4] = ((add_len >> 24) & 0xff);
3895 	buf[5] = ((add_len >> 16) & 0xff);
3896 	buf[6] = ((add_len >> 8) & 0xff);
3897 	buf[7] = (add_len & 0xff);
3898 
3899 	transport_kunmap_first_data_page(cmd);
3900 
3901 	return 0;
3902 }
3903 
3904 /*
3905  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
3906  *
3907  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
3908  */
3909 static int core_scsi3_pri_read_reservation(struct se_cmd *cmd)
3910 {
3911 	struct se_device *se_dev = cmd->se_dev;
3912 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
3913 	struct t10_pr_registration *pr_reg;
3914 	unsigned char *buf;
3915 	u64 pr_res_key;
3916 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
3917 
3918 	if (cmd->data_length < 8) {
3919 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
3920 			" too small\n", cmd->data_length);
3921 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
3922 	}
3923 
3924 	buf = transport_kmap_first_data_page(cmd);
3925 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
3926 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
3927 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
3928 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
3929 
3930 	spin_lock(&se_dev->dev_reservation_lock);
3931 	pr_reg = se_dev->dev_pr_res_holder;
3932 	if ((pr_reg)) {
3933 		/*
3934 		 * Set the hardcoded Additional Length
3935 		 */
3936 		buf[4] = ((add_len >> 24) & 0xff);
3937 		buf[5] = ((add_len >> 16) & 0xff);
3938 		buf[6] = ((add_len >> 8) & 0xff);
3939 		buf[7] = (add_len & 0xff);
3940 
3941 		if (cmd->data_length < 22)
3942 			goto err;
3943 
3944 		/*
3945 		 * Set the Reservation key.
3946 		 *
3947 		 * From spc4r17, section 5.7.10:
3948 		 * A persistent reservation holder has its reservation key
3949 		 * returned in the parameter data from a PERSISTENT
3950 		 * RESERVE IN command with READ RESERVATION service action as
3951 		 * follows:
3952 		 * a) For a persistent reservation of the type Write Exclusive
3953 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
3954 		 *      the reservation key shall be set to zero; or
3955 		 * b) For all other persistent reservation types, the
3956 		 *    reservation key shall be set to the registered
3957 		 *    reservation key for the I_T nexus that holds the
3958 		 *    persistent reservation.
3959 		 */
3960 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3961 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
3962 			pr_res_key = 0;
3963 		else
3964 			pr_res_key = pr_reg->pr_res_key;
3965 
3966 		buf[8] = ((pr_res_key >> 56) & 0xff);
3967 		buf[9] = ((pr_res_key >> 48) & 0xff);
3968 		buf[10] = ((pr_res_key >> 40) & 0xff);
3969 		buf[11] = ((pr_res_key >> 32) & 0xff);
3970 		buf[12] = ((pr_res_key >> 24) & 0xff);
3971 		buf[13] = ((pr_res_key >> 16) & 0xff);
3972 		buf[14] = ((pr_res_key >> 8) & 0xff);
3973 		buf[15] = (pr_res_key & 0xff);
3974 		/*
3975 		 * Set the SCOPE and TYPE
3976 		 */
3977 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
3978 			  (pr_reg->pr_res_type & 0x0f);
3979 	}
3980 
3981 err:
3982 	spin_unlock(&se_dev->dev_reservation_lock);
3983 	transport_kunmap_first_data_page(cmd);
3984 
3985 	return 0;
3986 }
3987 
3988 /*
3989  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
3990  *
3991  * See spc4r17 section 6.13.4 Table 165
3992  */
3993 static int core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
3994 {
3995 	struct se_device *dev = cmd->se_dev;
3996 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3997 	unsigned char *buf;
3998 	u16 add_len = 8; /* Hardcoded to 8. */
3999 
4000 	if (cmd->data_length < 6) {
4001 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
4002 			" %u too small\n", cmd->data_length);
4003 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
4004 	}
4005 
4006 	buf = transport_kmap_first_data_page(cmd);
4007 
4008 	buf[0] = ((add_len << 8) & 0xff);
4009 	buf[1] = (add_len & 0xff);
4010 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
4011 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
4012 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
4013 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
4014 	/*
4015 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
4016 	 * set the TMV: Task Mask Valid bit.
4017 	 */
4018 	buf[3] |= 0x80;
4019 	/*
4020 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
4021 	 */
4022 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
4023 	/*
4024 	 * PTPL_A: Persistence across Target Power Loss Active bit
4025 	 */
4026 	if (pr_tmpl->pr_aptpl_active)
4027 		buf[3] |= 0x01;
4028 	/*
4029 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
4030 	 */
4031 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4032 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
4033 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
4034 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
4035 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
4036 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4037 
4038 	transport_kunmap_first_data_page(cmd);
4039 
4040 	return 0;
4041 }
4042 
4043 /*
4044  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
4045  *
4046  * See spc4r17 section 6.13.5 Table 168 and 169
4047  */
4048 static int core_scsi3_pri_read_full_status(struct se_cmd *cmd)
4049 {
4050 	struct se_device *se_dev = cmd->se_dev;
4051 	struct se_node_acl *se_nacl;
4052 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
4053 	struct se_portal_group *se_tpg;
4054 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
4055 	struct t10_reservation *pr_tmpl = &se_dev->se_sub_dev->t10_pr;
4056 	unsigned char *buf;
4057 	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
4058 	u32 off = 8; /* off into first Full Status descriptor */
4059 	int format_code = 0;
4060 
4061 	if (cmd->data_length < 8) {
4062 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
4063 			" too small\n", cmd->data_length);
4064 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
4065 	}
4066 
4067 	buf = transport_kmap_first_data_page(cmd);
4068 
4069 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
4070 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
4071 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
4072 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
4073 
4074 	spin_lock(&pr_tmpl->registration_lock);
4075 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
4076 			&pr_tmpl->registration_list, pr_reg_list) {
4077 
4078 		se_nacl = pr_reg->pr_reg_nacl;
4079 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
4080 		add_desc_len = 0;
4081 
4082 		atomic_inc(&pr_reg->pr_res_holders);
4083 		smp_mb__after_atomic_inc();
4084 		spin_unlock(&pr_tmpl->registration_lock);
4085 		/*
4086 		 * Determine expected length of $FABRIC_MOD specific
4087 		 * TransportID full status descriptor..
4088 		 */
4089 		exp_desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id_len(
4090 				se_tpg, se_nacl, pr_reg, &format_code);
4091 
4092 		if ((exp_desc_len + add_len) > cmd->data_length) {
4093 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
4094 				" out of buffer: %d\n", cmd->data_length);
4095 			spin_lock(&pr_tmpl->registration_lock);
4096 			atomic_dec(&pr_reg->pr_res_holders);
4097 			smp_mb__after_atomic_dec();
4098 			break;
4099 		}
4100 		/*
4101 		 * Set RESERVATION KEY
4102 		 */
4103 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
4104 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
4105 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
4106 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
4107 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
4108 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
4109 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
4110 		buf[off++] = (pr_reg->pr_res_key & 0xff);
4111 		off += 4; /* Skip Over Reserved area */
4112 
4113 		/*
4114 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
4115 		 */
4116 		if (pr_reg->pr_reg_all_tg_pt)
4117 			buf[off] = 0x02;
4118 		/*
4119 		 * The struct se_lun pointer will be present for the
4120 		 * reservation holder for PR_HOLDER bit.
4121 		 *
4122 		 * Also, if this registration is the reservation
4123 		 * holder, fill in SCOPE and TYPE in the next byte.
4124 		 */
4125 		if (pr_reg->pr_res_holder) {
4126 			buf[off++] |= 0x01;
4127 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
4128 				     (pr_reg->pr_res_type & 0x0f);
4129 		} else
4130 			off += 2;
4131 
4132 		off += 4; /* Skip over reserved area */
4133 		/*
4134 		 * From spc4r17 6.3.15:
4135 		 *
4136 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4137 		 * IDENTIFIER field contains the relative port identifier (see
4138 		 * 3.1.120) of the target port that is part of the I_T nexus
4139 		 * described by this full status descriptor. If the ALL_TG_PT
4140 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4141 		 * IDENTIFIER field are not defined by this standard.
4142 		 */
4143 		if (!pr_reg->pr_reg_all_tg_pt) {
4144 			struct se_port *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
4145 
4146 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
4147 			buf[off++] = (port->sep_rtpi & 0xff);
4148 		} else
4149 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFER */
4150 
4151 		/*
4152 		 * Now, have the $FABRIC_MOD fill in the protocol identifier
4153 		 */
4154 		desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id(se_tpg,
4155 				se_nacl, pr_reg, &format_code, &buf[off+4]);
4156 
4157 		spin_lock(&pr_tmpl->registration_lock);
4158 		atomic_dec(&pr_reg->pr_res_holders);
4159 		smp_mb__after_atomic_dec();
4160 		/*
4161 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4162 		 */
4163 		buf[off++] = ((desc_len >> 24) & 0xff);
4164 		buf[off++] = ((desc_len >> 16) & 0xff);
4165 		buf[off++] = ((desc_len >> 8) & 0xff);
4166 		buf[off++] = (desc_len & 0xff);
4167 		/*
4168 		 * Size of full desctipor header minus TransportID
4169 		 * containing $FABRIC_MOD specific) initiator device/port
4170 		 * WWN information.
4171 		 *
4172 		 *  See spc4r17 Section 6.13.5 Table 169
4173 		 */
4174 		add_desc_len = (24 + desc_len);
4175 
4176 		off += desc_len;
4177 		add_len += add_desc_len;
4178 	}
4179 	spin_unlock(&pr_tmpl->registration_lock);
4180 	/*
4181 	 * Set ADDITIONAL_LENGTH
4182 	 */
4183 	buf[4] = ((add_len >> 24) & 0xff);
4184 	buf[5] = ((add_len >> 16) & 0xff);
4185 	buf[6] = ((add_len >> 8) & 0xff);
4186 	buf[7] = (add_len & 0xff);
4187 
4188 	transport_kunmap_first_data_page(cmd);
4189 
4190 	return 0;
4191 }
4192 
4193 static int core_scsi3_emulate_pr_in(struct se_cmd *cmd, unsigned char *cdb)
4194 {
4195 	switch (cdb[1] & 0x1f) {
4196 	case PRI_READ_KEYS:
4197 		return core_scsi3_pri_read_keys(cmd);
4198 	case PRI_READ_RESERVATION:
4199 		return core_scsi3_pri_read_reservation(cmd);
4200 	case PRI_REPORT_CAPABILITIES:
4201 		return core_scsi3_pri_report_capabilities(cmd);
4202 	case PRI_READ_FULL_STATUS:
4203 		return core_scsi3_pri_read_full_status(cmd);
4204 	default:
4205 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4206 			" action: 0x%02x\n", cdb[1] & 0x1f);
4207 		return PYX_TRANSPORT_INVALID_CDB_FIELD;
4208 	}
4209 
4210 }
4211 
4212 int core_scsi3_emulate_pr(struct se_cmd *cmd)
4213 {
4214 	unsigned char *cdb = &cmd->t_task_cdb[0];
4215 	struct se_device *dev = cmd->se_dev;
4216 	/*
4217 	 * Following spc2r20 5.5.1 Reservations overview:
4218 	 *
4219 	 * If a logical unit has been reserved by any RESERVE command and is
4220 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4221 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4222 	 * initiator or service action and shall terminate with a RESERVATION
4223 	 * CONFLICT status.
4224 	 */
4225 	if (dev->dev_flags & DF_SPC2_RESERVATIONS) {
4226 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4227 			" SPC-2 reservation is held, returning"
4228 			" RESERVATION_CONFLICT\n");
4229 		return PYX_TRANSPORT_RESERVATION_CONFLICT;
4230 	}
4231 
4232 	return (cdb[0] == PERSISTENT_RESERVE_OUT) ?
4233 	       core_scsi3_emulate_pr_out(cmd, cdb) :
4234 	       core_scsi3_emulate_pr_in(cmd, cdb);
4235 }
4236 
4237 static int core_pt_reservation_check(struct se_cmd *cmd, u32 *pr_res_type)
4238 {
4239 	return 0;
4240 }
4241 
4242 static int core_pt_seq_non_holder(
4243 	struct se_cmd *cmd,
4244 	unsigned char *cdb,
4245 	u32 pr_reg_type)
4246 {
4247 	return 0;
4248 }
4249 
4250 int core_setup_reservations(struct se_device *dev, int force_pt)
4251 {
4252 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
4253 	struct t10_reservation *rest = &su_dev->t10_pr;
4254 	/*
4255 	 * If this device is from Target_Core_Mod/pSCSI, use the reservations
4256 	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
4257 	 * cause a problem because libata and some SATA RAID HBAs appear
4258 	 * under Linux/SCSI, but to emulate reservations themselves.
4259 	 */
4260 	if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
4261 	    !(dev->se_sub_dev->se_dev_attrib.emulate_reservations)) || force_pt) {
4262 		rest->res_type = SPC_PASSTHROUGH;
4263 		rest->pr_ops.t10_reservation_check = &core_pt_reservation_check;
4264 		rest->pr_ops.t10_seq_non_holder = &core_pt_seq_non_holder;
4265 		pr_debug("%s: Using SPC_PASSTHROUGH, no reservation"
4266 			" emulation\n", dev->transport->name);
4267 		return 0;
4268 	}
4269 	/*
4270 	 * If SPC-3 or above is reported by real or emulated struct se_device,
4271 	 * use emulated Persistent Reservations.
4272 	 */
4273 	if (dev->transport->get_device_rev(dev) >= SCSI_3) {
4274 		rest->res_type = SPC3_PERSISTENT_RESERVATIONS;
4275 		rest->pr_ops.t10_reservation_check = &core_scsi3_pr_reservation_check;
4276 		rest->pr_ops.t10_seq_non_holder = &core_scsi3_pr_seq_non_holder;
4277 		pr_debug("%s: Using SPC3_PERSISTENT_RESERVATIONS"
4278 			" emulation\n", dev->transport->name);
4279 	} else {
4280 		rest->res_type = SPC2_RESERVATIONS;
4281 		rest->pr_ops.t10_reservation_check = &core_scsi2_reservation_check;
4282 		rest->pr_ops.t10_seq_non_holder =
4283 				&core_scsi2_reservation_seq_non_holder;
4284 		pr_debug("%s: Using SPC2_RESERVATIONS emulation\n",
4285 			dev->transport->name);
4286 	}
4287 
4288 	return 0;
4289 }
4290