xref: /linux/drivers/target/target_core_pr.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
1 /*******************************************************************************
2  * Filename:  target_core_pr.c
3  *
4  * This file contains SPC-3 compliant persistent reservations and
5  * legacy SPC-2 reservations with compatible reservation handling (CRH=1)
6  *
7  * Copyright (c) 2009, 2010 Rising Tide Systems
8  * Copyright (c) 2009, 2010 Linux-iSCSI.org
9  *
10  * Nicholas A. Bellinger <nab@kernel.org>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25  *
26  ******************************************************************************/
27 
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/list.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_cmnd.h>
33 #include <asm/unaligned.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_backend.h>
37 #include <target/target_core_fabric.h>
38 #include <target/target_core_configfs.h>
39 
40 #include "target_core_internal.h"
41 #include "target_core_pr.h"
42 #include "target_core_ua.h"
43 
44 /*
45  * Used for Specify Initiator Ports Capable Bit (SPEC_I_PT)
46  */
47 struct pr_transport_id_holder {
48 	int dest_local_nexus;
49 	struct t10_pr_registration *dest_pr_reg;
50 	struct se_portal_group *dest_tpg;
51 	struct se_node_acl *dest_node_acl;
52 	struct se_dev_entry *dest_se_deve;
53 	struct list_head dest_list;
54 };
55 
56 int core_pr_dump_initiator_port(
57 	struct t10_pr_registration *pr_reg,
58 	char *buf,
59 	u32 size)
60 {
61 	if (!pr_reg->isid_present_at_reg)
62 		return 0;
63 
64 	snprintf(buf, size, ",i,0x%s", &pr_reg->pr_reg_isid[0]);
65 	return 1;
66 }
67 
68 static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
69 			struct t10_pr_registration *, int);
70 
71 static int core_scsi2_reservation_seq_non_holder(
72 	struct se_cmd *cmd,
73 	unsigned char *cdb,
74 	u32 pr_reg_type)
75 {
76 	switch (cdb[0]) {
77 	case INQUIRY:
78 	case RELEASE:
79 	case RELEASE_10:
80 		return 0;
81 	default:
82 		return 1;
83 	}
84 
85 	return 1;
86 }
87 
88 static int core_scsi2_reservation_check(struct se_cmd *cmd, u32 *pr_reg_type)
89 {
90 	struct se_device *dev = cmd->se_dev;
91 	struct se_session *sess = cmd->se_sess;
92 	int ret;
93 
94 	if (!sess)
95 		return 0;
96 
97 	spin_lock(&dev->dev_reservation_lock);
98 	if (!dev->dev_reserved_node_acl || !sess) {
99 		spin_unlock(&dev->dev_reservation_lock);
100 		return 0;
101 	}
102 	if (dev->dev_reserved_node_acl != sess->se_node_acl) {
103 		spin_unlock(&dev->dev_reservation_lock);
104 		return -EINVAL;
105 	}
106 	if (!(dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID)) {
107 		spin_unlock(&dev->dev_reservation_lock);
108 		return 0;
109 	}
110 	ret = (dev->dev_res_bin_isid == sess->sess_bin_isid) ? 0 : -EINVAL;
111 	spin_unlock(&dev->dev_reservation_lock);
112 
113 	return ret;
114 }
115 
116 static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
117 					struct se_node_acl *, struct se_session *);
118 static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
119 
120 static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
121 {
122 	struct se_session *se_sess = cmd->se_sess;
123 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
124 	struct t10_pr_registration *pr_reg;
125 	struct t10_reservation *pr_tmpl = &su_dev->t10_pr;
126 	int crh = (su_dev->t10_pr.res_type == SPC3_PERSISTENT_RESERVATIONS);
127 	int conflict = 0;
128 
129 	if (!crh)
130 		return -EINVAL;
131 
132 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
133 			se_sess);
134 	if (pr_reg) {
135 		/*
136 		 * From spc4r17 5.7.3 Exceptions to SPC-2 RESERVE and RELEASE
137 		 * behavior
138 		 *
139 		 * A RESERVE(6) or RESERVE(10) command shall complete with GOOD
140 		 * status, but no reservation shall be established and the
141 		 * persistent reservation shall not be changed, if the command
142 		 * is received from a) and b) below.
143 		 *
144 		 * A RELEASE(6) or RELEASE(10) command shall complete with GOOD
145 		 * status, but the persistent reservation shall not be released,
146 		 * if the command is received from a) and b)
147 		 *
148 		 * a) An I_T nexus that is a persistent reservation holder; or
149 		 * b) An I_T nexus that is registered if a registrants only or
150 		 *    all registrants type persistent reservation is present.
151 		 *
152 		 * In all other cases, a RESERVE(6) command, RESERVE(10) command,
153 		 * RELEASE(6) command, or RELEASE(10) command shall be processed
154 		 * as defined in SPC-2.
155 		 */
156 		if (pr_reg->pr_res_holder) {
157 			core_scsi3_put_pr_reg(pr_reg);
158 			return 1;
159 		}
160 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
161 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
162 		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
163 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
164 			core_scsi3_put_pr_reg(pr_reg);
165 			return 1;
166 		}
167 		core_scsi3_put_pr_reg(pr_reg);
168 		conflict = 1;
169 	} else {
170 		/*
171 		 * Following spc2r20 5.5.1 Reservations overview:
172 		 *
173 		 * If a logical unit has executed a PERSISTENT RESERVE OUT
174 		 * command with the REGISTER or the REGISTER AND IGNORE
175 		 * EXISTING KEY service action and is still registered by any
176 		 * initiator, all RESERVE commands and all RELEASE commands
177 		 * regardless of initiator shall conflict and shall terminate
178 		 * with a RESERVATION CONFLICT status.
179 		 */
180 		spin_lock(&pr_tmpl->registration_lock);
181 		conflict = (list_empty(&pr_tmpl->registration_list)) ? 0 : 1;
182 		spin_unlock(&pr_tmpl->registration_lock);
183 	}
184 
185 	if (conflict) {
186 		pr_err("Received legacy SPC-2 RESERVE/RELEASE"
187 			" while active SPC-3 registrations exist,"
188 			" returning RESERVATION_CONFLICT\n");
189 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
190 		return -EBUSY;
191 	}
192 
193 	return 0;
194 }
195 
196 int target_scsi2_reservation_release(struct se_cmd *cmd)
197 {
198 	struct se_device *dev = cmd->se_dev;
199 	struct se_session *sess = cmd->se_sess;
200 	struct se_portal_group *tpg = sess->se_tpg;
201 	int ret = 0, rc;
202 
203 	if (!sess || !tpg)
204 		goto out;
205 	rc = target_check_scsi2_reservation_conflict(cmd);
206 	if (rc == 1)
207 		goto out;
208 	else if (rc < 0) {
209 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
210 		ret = -EINVAL;
211 		goto out;
212 	}
213 
214 	ret = 0;
215 	spin_lock(&dev->dev_reservation_lock);
216 	if (!dev->dev_reserved_node_acl || !sess)
217 		goto out_unlock;
218 
219 	if (dev->dev_reserved_node_acl != sess->se_node_acl)
220 		goto out_unlock;
221 
222 	if (dev->dev_res_bin_isid != sess->sess_bin_isid)
223 		goto out_unlock;
224 
225 	dev->dev_reserved_node_acl = NULL;
226 	dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
227 	if (dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID) {
228 		dev->dev_res_bin_isid = 0;
229 		dev->dev_flags &= ~DF_SPC2_RESERVATIONS_WITH_ISID;
230 	}
231 	pr_debug("SCSI-2 Released reservation for %s LUN: %u ->"
232 		" MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
233 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
234 		sess->se_node_acl->initiatorname);
235 
236 out_unlock:
237 	spin_unlock(&dev->dev_reservation_lock);
238 out:
239 	if (!ret)
240 		target_complete_cmd(cmd, GOOD);
241 	return ret;
242 }
243 
244 int target_scsi2_reservation_reserve(struct se_cmd *cmd)
245 {
246 	struct se_device *dev = cmd->se_dev;
247 	struct se_session *sess = cmd->se_sess;
248 	struct se_portal_group *tpg = sess->se_tpg;
249 	int ret = 0, rc;
250 
251 	if ((cmd->t_task_cdb[1] & 0x01) &&
252 	    (cmd->t_task_cdb[1] & 0x02)) {
253 		pr_err("LongIO and Obselete Bits set, returning"
254 				" ILLEGAL_REQUEST\n");
255 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
256 		ret = -EINVAL;
257 		goto out;
258 	}
259 	/*
260 	 * This is currently the case for target_core_mod passthrough struct se_cmd
261 	 * ops
262 	 */
263 	if (!sess || !tpg)
264 		goto out;
265 	rc = target_check_scsi2_reservation_conflict(cmd);
266 	if (rc == 1)
267 		goto out;
268 	else if (rc < 0) {
269 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
270 		ret = -EINVAL;
271 		goto out;
272 	}
273 
274 	ret = 0;
275 	spin_lock(&dev->dev_reservation_lock);
276 	if (dev->dev_reserved_node_acl &&
277 	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
278 		pr_err("SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
279 			tpg->se_tpg_tfo->get_fabric_name());
280 		pr_err("Original reserver LUN: %u %s\n",
281 			cmd->se_lun->unpacked_lun,
282 			dev->dev_reserved_node_acl->initiatorname);
283 		pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u"
284 			" from %s \n", cmd->se_lun->unpacked_lun,
285 			cmd->se_deve->mapped_lun,
286 			sess->se_node_acl->initiatorname);
287 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
288 		ret = -EINVAL;
289 		goto out_unlock;
290 	}
291 
292 	dev->dev_reserved_node_acl = sess->se_node_acl;
293 	dev->dev_flags |= DF_SPC2_RESERVATIONS;
294 	if (sess->sess_bin_isid != 0) {
295 		dev->dev_res_bin_isid = sess->sess_bin_isid;
296 		dev->dev_flags |= DF_SPC2_RESERVATIONS_WITH_ISID;
297 	}
298 	pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
299 		" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
300 		cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun,
301 		sess->se_node_acl->initiatorname);
302 
303 out_unlock:
304 	spin_unlock(&dev->dev_reservation_lock);
305 out:
306 	if (!ret)
307 		target_complete_cmd(cmd, GOOD);
308 	return ret;
309 }
310 
311 
312 /*
313  * Begin SPC-3/SPC-4 Persistent Reservations emulation support
314  *
315  * This function is called by those initiator ports who are *NOT*
316  * the active PR reservation holder when a reservation is present.
317  */
318 static int core_scsi3_pr_seq_non_holder(
319 	struct se_cmd *cmd,
320 	unsigned char *cdb,
321 	u32 pr_reg_type)
322 {
323 	struct se_dev_entry *se_deve;
324 	struct se_session *se_sess = cmd->se_sess;
325 	int other_cdb = 0, ignore_reg;
326 	int registered_nexus = 0, ret = 1; /* Conflict by default */
327 	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
328 	int we = 0; /* Write Exclusive */
329 	int legacy = 0; /* Act like a legacy device and return
330 			 * RESERVATION CONFLICT on some CDBs */
331 	/*
332 	 * A legacy SPC-2 reservation is being held.
333 	 */
334 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS)
335 		return core_scsi2_reservation_seq_non_holder(cmd,
336 					cdb, pr_reg_type);
337 
338 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
339 	/*
340 	 * Determine if the registration should be ignored due to
341 	 * non-matching ISIDs in core_scsi3_pr_reservation_check().
342 	 */
343 	ignore_reg = (pr_reg_type & 0x80000000);
344 	if (ignore_reg)
345 		pr_reg_type &= ~0x80000000;
346 
347 	switch (pr_reg_type) {
348 	case PR_TYPE_WRITE_EXCLUSIVE:
349 		we = 1;
350 	case PR_TYPE_EXCLUSIVE_ACCESS:
351 		/*
352 		 * Some commands are only allowed for the persistent reservation
353 		 * holder.
354 		 */
355 		if ((se_deve->def_pr_registered) && !(ignore_reg))
356 			registered_nexus = 1;
357 		break;
358 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
359 		we = 1;
360 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
361 		/*
362 		 * Some commands are only allowed for registered I_T Nexuses.
363 		 */
364 		reg_only = 1;
365 		if ((se_deve->def_pr_registered) && !(ignore_reg))
366 			registered_nexus = 1;
367 		break;
368 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
369 		we = 1;
370 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
371 		/*
372 		 * Each registered I_T Nexus is a reservation holder.
373 		 */
374 		all_reg = 1;
375 		if ((se_deve->def_pr_registered) && !(ignore_reg))
376 			registered_nexus = 1;
377 		break;
378 	default:
379 		return -EINVAL;
380 	}
381 	/*
382 	 * Referenced from spc4r17 table 45 for *NON* PR holder access
383 	 */
384 	switch (cdb[0]) {
385 	case SECURITY_PROTOCOL_IN:
386 		if (registered_nexus)
387 			return 0;
388 		ret = (we) ? 0 : 1;
389 		break;
390 	case MODE_SENSE:
391 	case MODE_SENSE_10:
392 	case READ_ATTRIBUTE:
393 	case READ_BUFFER:
394 	case RECEIVE_DIAGNOSTIC:
395 		if (legacy) {
396 			ret = 1;
397 			break;
398 		}
399 		if (registered_nexus) {
400 			ret = 0;
401 			break;
402 		}
403 		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
404 		break;
405 	case PERSISTENT_RESERVE_OUT:
406 		/*
407 		 * This follows PERSISTENT_RESERVE_OUT service actions that
408 		 * are allowed in the presence of various reservations.
409 		 * See spc4r17, table 46
410 		 */
411 		switch (cdb[1] & 0x1f) {
412 		case PRO_CLEAR:
413 		case PRO_PREEMPT:
414 		case PRO_PREEMPT_AND_ABORT:
415 			ret = (registered_nexus) ? 0 : 1;
416 			break;
417 		case PRO_REGISTER:
418 		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
419 			ret = 0;
420 			break;
421 		case PRO_REGISTER_AND_MOVE:
422 		case PRO_RESERVE:
423 			ret = 1;
424 			break;
425 		case PRO_RELEASE:
426 			ret = (registered_nexus) ? 0 : 1;
427 			break;
428 		default:
429 			pr_err("Unknown PERSISTENT_RESERVE_OUT service"
430 				" action: 0x%02x\n", cdb[1] & 0x1f);
431 			return -EINVAL;
432 		}
433 		break;
434 	case RELEASE:
435 	case RELEASE_10:
436 		/* Handled by CRH=1 in target_scsi2_reservation_release() */
437 		ret = 0;
438 		break;
439 	case RESERVE:
440 	case RESERVE_10:
441 		/* Handled by CRH=1 in target_scsi2_reservation_reserve() */
442 		ret = 0;
443 		break;
444 	case TEST_UNIT_READY:
445 		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
446 		break;
447 	case MAINTENANCE_IN:
448 		switch (cdb[1] & 0x1f) {
449 		case MI_MANAGEMENT_PROTOCOL_IN:
450 			if (registered_nexus) {
451 				ret = 0;
452 				break;
453 			}
454 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
455 			break;
456 		case MI_REPORT_SUPPORTED_OPERATION_CODES:
457 		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
458 			if (legacy) {
459 				ret = 1;
460 				break;
461 			}
462 			if (registered_nexus) {
463 				ret = 0;
464 				break;
465 			}
466 			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
467 			break;
468 		case MI_REPORT_ALIASES:
469 		case MI_REPORT_IDENTIFYING_INFORMATION:
470 		case MI_REPORT_PRIORITY:
471 		case MI_REPORT_TARGET_PGS:
472 		case MI_REPORT_TIMESTAMP:
473 			ret = 0; /* Allowed */
474 			break;
475 		default:
476 			pr_err("Unknown MI Service Action: 0x%02x\n",
477 				(cdb[1] & 0x1f));
478 			return -EINVAL;
479 		}
480 		break;
481 	case ACCESS_CONTROL_IN:
482 	case ACCESS_CONTROL_OUT:
483 	case INQUIRY:
484 	case LOG_SENSE:
485 	case READ_MEDIA_SERIAL_NUMBER:
486 	case REPORT_LUNS:
487 	case REQUEST_SENSE:
488 	case PERSISTENT_RESERVE_IN:
489 		ret = 0; /*/ Allowed CDBs */
490 		break;
491 	default:
492 		other_cdb = 1;
493 		break;
494 	}
495 	/*
496 	 * Case where the CDB is explicitly allowed in the above switch
497 	 * statement.
498 	 */
499 	if (!ret && !other_cdb) {
500 		pr_debug("Allowing explict CDB: 0x%02x for %s"
501 			" reservation holder\n", cdb[0],
502 			core_scsi3_pr_dump_type(pr_reg_type));
503 
504 		return ret;
505 	}
506 	/*
507 	 * Check if write exclusive initiator ports *NOT* holding the
508 	 * WRITE_EXCLUSIVE_* reservation.
509 	 */
510 	if (we && !registered_nexus) {
511 		if (cmd->data_direction == DMA_TO_DEVICE) {
512 			/*
513 			 * Conflict for write exclusive
514 			 */
515 			pr_debug("%s Conflict for unregistered nexus"
516 				" %s CDB: 0x%02x to %s reservation\n",
517 				transport_dump_cmd_direction(cmd),
518 				se_sess->se_node_acl->initiatorname, cdb[0],
519 				core_scsi3_pr_dump_type(pr_reg_type));
520 			return 1;
521 		} else {
522 			/*
523 			 * Allow non WRITE CDBs for all Write Exclusive
524 			 * PR TYPEs to pass for registered and
525 			 * non-registered_nexuxes NOT holding the reservation.
526 			 *
527 			 * We only make noise for the unregisterd nexuses,
528 			 * as we expect registered non-reservation holding
529 			 * nexuses to issue CDBs.
530 			 */
531 
532 			if (!registered_nexus) {
533 				pr_debug("Allowing implict CDB: 0x%02x"
534 					" for %s reservation on unregistered"
535 					" nexus\n", cdb[0],
536 					core_scsi3_pr_dump_type(pr_reg_type));
537 			}
538 
539 			return 0;
540 		}
541 	} else if ((reg_only) || (all_reg)) {
542 		if (registered_nexus) {
543 			/*
544 			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
545 			 * allow commands from registered nexuses.
546 			 */
547 
548 			pr_debug("Allowing implict CDB: 0x%02x for %s"
549 				" reservation\n", cdb[0],
550 				core_scsi3_pr_dump_type(pr_reg_type));
551 
552 			return 0;
553 		}
554 	}
555 	pr_debug("%s Conflict for %sregistered nexus %s CDB: 0x%2x"
556 		" for %s reservation\n", transport_dump_cmd_direction(cmd),
557 		(registered_nexus) ? "" : "un",
558 		se_sess->se_node_acl->initiatorname, cdb[0],
559 		core_scsi3_pr_dump_type(pr_reg_type));
560 
561 	return 1; /* Conflict by default */
562 }
563 
564 static u32 core_scsi3_pr_generation(struct se_device *dev)
565 {
566 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
567 	u32 prg;
568 	/*
569 	 * PRGeneration field shall contain the value of a 32-bit wrapping
570 	 * counter mainted by the device server.
571 	 *
572 	 * Note that this is done regardless of Active Persist across
573 	 * Target PowerLoss (APTPL)
574 	 *
575 	 * See spc4r17 section 6.3.12 READ_KEYS service action
576 	 */
577 	spin_lock(&dev->dev_reservation_lock);
578 	prg = su_dev->t10_pr.pr_generation++;
579 	spin_unlock(&dev->dev_reservation_lock);
580 
581 	return prg;
582 }
583 
584 static int core_scsi3_pr_reservation_check(
585 	struct se_cmd *cmd,
586 	u32 *pr_reg_type)
587 {
588 	struct se_device *dev = cmd->se_dev;
589 	struct se_session *sess = cmd->se_sess;
590 	int ret;
591 
592 	if (!sess)
593 		return 0;
594 	/*
595 	 * A legacy SPC-2 reservation is being held.
596 	 */
597 	if (dev->dev_flags & DF_SPC2_RESERVATIONS)
598 		return core_scsi2_reservation_check(cmd, pr_reg_type);
599 
600 	spin_lock(&dev->dev_reservation_lock);
601 	if (!dev->dev_pr_res_holder) {
602 		spin_unlock(&dev->dev_reservation_lock);
603 		return 0;
604 	}
605 	*pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
606 	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
607 	if (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl) {
608 		spin_unlock(&dev->dev_reservation_lock);
609 		return -EINVAL;
610 	}
611 	if (!dev->dev_pr_res_holder->isid_present_at_reg) {
612 		spin_unlock(&dev->dev_reservation_lock);
613 		return 0;
614 	}
615 	ret = (dev->dev_pr_res_holder->pr_reg_bin_isid ==
616 	       sess->sess_bin_isid) ? 0 : -EINVAL;
617 	/*
618 	 * Use bit in *pr_reg_type to notify ISID mismatch in
619 	 * core_scsi3_pr_seq_non_holder().
620 	 */
621 	if (ret != 0)
622 		*pr_reg_type |= 0x80000000;
623 	spin_unlock(&dev->dev_reservation_lock);
624 
625 	return ret;
626 }
627 
628 static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
629 	struct se_device *dev,
630 	struct se_node_acl *nacl,
631 	struct se_dev_entry *deve,
632 	unsigned char *isid,
633 	u64 sa_res_key,
634 	int all_tg_pt,
635 	int aptpl)
636 {
637 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
638 	struct t10_pr_registration *pr_reg;
639 
640 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_ATOMIC);
641 	if (!pr_reg) {
642 		pr_err("Unable to allocate struct t10_pr_registration\n");
643 		return NULL;
644 	}
645 
646 	pr_reg->pr_aptpl_buf = kzalloc(su_dev->t10_pr.pr_aptpl_buf_len,
647 					GFP_ATOMIC);
648 	if (!pr_reg->pr_aptpl_buf) {
649 		pr_err("Unable to allocate pr_reg->pr_aptpl_buf\n");
650 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
651 		return NULL;
652 	}
653 
654 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
655 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
656 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
657 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
658 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
659 	atomic_set(&pr_reg->pr_res_holders, 0);
660 	pr_reg->pr_reg_nacl = nacl;
661 	pr_reg->pr_reg_deve = deve;
662 	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
663 	pr_reg->pr_aptpl_target_lun = deve->se_lun->unpacked_lun;
664 	pr_reg->pr_res_key = sa_res_key;
665 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
666 	pr_reg->pr_reg_aptpl = aptpl;
667 	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
668 	/*
669 	 * If an ISID value for this SCSI Initiator Port exists,
670 	 * save it to the registration now.
671 	 */
672 	if (isid != NULL) {
673 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
674 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
675 		pr_reg->isid_present_at_reg = 1;
676 	}
677 
678 	return pr_reg;
679 }
680 
681 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *);
682 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *);
683 
684 /*
685  * Function used for handling PR registrations for ALL_TG_PT=1 and ALL_TG_PT=0
686  * modes.
687  */
688 static struct t10_pr_registration *__core_scsi3_alloc_registration(
689 	struct se_device *dev,
690 	struct se_node_acl *nacl,
691 	struct se_dev_entry *deve,
692 	unsigned char *isid,
693 	u64 sa_res_key,
694 	int all_tg_pt,
695 	int aptpl)
696 {
697 	struct se_dev_entry *deve_tmp;
698 	struct se_node_acl *nacl_tmp;
699 	struct se_port *port, *port_tmp;
700 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
701 	struct t10_pr_registration *pr_reg, *pr_reg_atp, *pr_reg_tmp, *pr_reg_tmp_safe;
702 	int ret;
703 	/*
704 	 * Create a registration for the I_T Nexus upon which the
705 	 * PROUT REGISTER was received.
706 	 */
707 	pr_reg = __core_scsi3_do_alloc_registration(dev, nacl, deve, isid,
708 			sa_res_key, all_tg_pt, aptpl);
709 	if (!pr_reg)
710 		return NULL;
711 	/*
712 	 * Return pointer to pr_reg for ALL_TG_PT=0
713 	 */
714 	if (!all_tg_pt)
715 		return pr_reg;
716 	/*
717 	 * Create list of matching SCSI Initiator Port registrations
718 	 * for ALL_TG_PT=1
719 	 */
720 	spin_lock(&dev->se_port_lock);
721 	list_for_each_entry_safe(port, port_tmp, &dev->dev_sep_list, sep_list) {
722 		atomic_inc(&port->sep_tg_pt_ref_cnt);
723 		smp_mb__after_atomic_inc();
724 		spin_unlock(&dev->se_port_lock);
725 
726 		spin_lock_bh(&port->sep_alua_lock);
727 		list_for_each_entry(deve_tmp, &port->sep_alua_list,
728 					alua_port_list) {
729 			/*
730 			 * This pointer will be NULL for demo mode MappedLUNs
731 			 * that have not been make explict via a ConfigFS
732 			 * MappedLUN group for the SCSI Initiator Node ACL.
733 			 */
734 			if (!deve_tmp->se_lun_acl)
735 				continue;
736 
737 			nacl_tmp = deve_tmp->se_lun_acl->se_lun_nacl;
738 			/*
739 			 * Skip the matching struct se_node_acl that is allocated
740 			 * above..
741 			 */
742 			if (nacl == nacl_tmp)
743 				continue;
744 			/*
745 			 * Only perform PR registrations for target ports on
746 			 * the same fabric module as the REGISTER w/ ALL_TG_PT=1
747 			 * arrived.
748 			 */
749 			if (tfo != nacl_tmp->se_tpg->se_tpg_tfo)
750 				continue;
751 			/*
752 			 * Look for a matching Initiator Node ACL in ASCII format
753 			 */
754 			if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname))
755 				continue;
756 
757 			atomic_inc(&deve_tmp->pr_ref_count);
758 			smp_mb__after_atomic_inc();
759 			spin_unlock_bh(&port->sep_alua_lock);
760 			/*
761 			 * Grab a configfs group dependency that is released
762 			 * for the exception path at label out: below, or upon
763 			 * completion of adding ALL_TG_PT=1 registrations in
764 			 * __core_scsi3_add_registration()
765 			 */
766 			ret = core_scsi3_lunacl_depend_item(deve_tmp);
767 			if (ret < 0) {
768 				pr_err("core_scsi3_lunacl_depend"
769 						"_item() failed\n");
770 				atomic_dec(&port->sep_tg_pt_ref_cnt);
771 				smp_mb__after_atomic_dec();
772 				atomic_dec(&deve_tmp->pr_ref_count);
773 				smp_mb__after_atomic_dec();
774 				goto out;
775 			}
776 			/*
777 			 * Located a matching SCSI Initiator Port on a different
778 			 * port, allocate the pr_reg_atp and attach it to the
779 			 * pr_reg->pr_reg_atp_list that will be processed once
780 			 * the original *pr_reg is processed in
781 			 * __core_scsi3_add_registration()
782 			 */
783 			pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
784 						nacl_tmp, deve_tmp, NULL,
785 						sa_res_key, all_tg_pt, aptpl);
786 			if (!pr_reg_atp) {
787 				atomic_dec(&port->sep_tg_pt_ref_cnt);
788 				smp_mb__after_atomic_dec();
789 				atomic_dec(&deve_tmp->pr_ref_count);
790 				smp_mb__after_atomic_dec();
791 				core_scsi3_lunacl_undepend_item(deve_tmp);
792 				goto out;
793 			}
794 
795 			list_add_tail(&pr_reg_atp->pr_reg_atp_mem_list,
796 				      &pr_reg->pr_reg_atp_list);
797 			spin_lock_bh(&port->sep_alua_lock);
798 		}
799 		spin_unlock_bh(&port->sep_alua_lock);
800 
801 		spin_lock(&dev->se_port_lock);
802 		atomic_dec(&port->sep_tg_pt_ref_cnt);
803 		smp_mb__after_atomic_dec();
804 	}
805 	spin_unlock(&dev->se_port_lock);
806 
807 	return pr_reg;
808 out:
809 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
810 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
811 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
812 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
813 		kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
814 	}
815 	kmem_cache_free(t10_pr_reg_cache, pr_reg);
816 	return NULL;
817 }
818 
819 int core_scsi3_alloc_aptpl_registration(
820 	struct t10_reservation *pr_tmpl,
821 	u64 sa_res_key,
822 	unsigned char *i_port,
823 	unsigned char *isid,
824 	u32 mapped_lun,
825 	unsigned char *t_port,
826 	u16 tpgt,
827 	u32 target_lun,
828 	int res_holder,
829 	int all_tg_pt,
830 	u8 type)
831 {
832 	struct t10_pr_registration *pr_reg;
833 
834 	if (!i_port || !t_port || !sa_res_key) {
835 		pr_err("Illegal parameters for APTPL registration\n");
836 		return -EINVAL;
837 	}
838 
839 	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
840 	if (!pr_reg) {
841 		pr_err("Unable to allocate struct t10_pr_registration\n");
842 		return -ENOMEM;
843 	}
844 	pr_reg->pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len, GFP_KERNEL);
845 
846 	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
847 	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
848 	INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
849 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
850 	INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
851 	atomic_set(&pr_reg->pr_res_holders, 0);
852 	pr_reg->pr_reg_nacl = NULL;
853 	pr_reg->pr_reg_deve = NULL;
854 	pr_reg->pr_res_mapped_lun = mapped_lun;
855 	pr_reg->pr_aptpl_target_lun = target_lun;
856 	pr_reg->pr_res_key = sa_res_key;
857 	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
858 	pr_reg->pr_reg_aptpl = 1;
859 	pr_reg->pr_reg_tg_pt_lun = NULL;
860 	pr_reg->pr_res_scope = 0; /* Always LUN_SCOPE */
861 	pr_reg->pr_res_type = type;
862 	/*
863 	 * If an ISID value had been saved in APTPL metadata for this
864 	 * SCSI Initiator Port, restore it now.
865 	 */
866 	if (isid != NULL) {
867 		pr_reg->pr_reg_bin_isid = get_unaligned_be64(isid);
868 		snprintf(pr_reg->pr_reg_isid, PR_REG_ISID_LEN, "%s", isid);
869 		pr_reg->isid_present_at_reg = 1;
870 	}
871 	/*
872 	 * Copy the i_port and t_port information from caller.
873 	 */
874 	snprintf(pr_reg->pr_iport, PR_APTPL_MAX_IPORT_LEN, "%s", i_port);
875 	snprintf(pr_reg->pr_tport, PR_APTPL_MAX_TPORT_LEN, "%s", t_port);
876 	pr_reg->pr_reg_tpgt = tpgt;
877 	/*
878 	 * Set pr_res_holder from caller, the pr_reg who is the reservation
879 	 * holder will get it's pointer set in core_scsi3_aptpl_reserve() once
880 	 * the Initiator Node LUN ACL from the fabric module is created for
881 	 * this registration.
882 	 */
883 	pr_reg->pr_res_holder = res_holder;
884 
885 	list_add_tail(&pr_reg->pr_reg_aptpl_list, &pr_tmpl->aptpl_reg_list);
886 	pr_debug("SPC-3 PR APTPL Successfully added registration%s from"
887 			" metadata\n", (res_holder) ? "+reservation" : "");
888 	return 0;
889 }
890 
891 static void core_scsi3_aptpl_reserve(
892 	struct se_device *dev,
893 	struct se_portal_group *tpg,
894 	struct se_node_acl *node_acl,
895 	struct t10_pr_registration *pr_reg)
896 {
897 	char i_buf[PR_REG_ISID_ID_LEN];
898 	int prf_isid;
899 
900 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
901 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
902 				PR_REG_ISID_ID_LEN);
903 
904 	spin_lock(&dev->dev_reservation_lock);
905 	dev->dev_pr_res_holder = pr_reg;
906 	spin_unlock(&dev->dev_reservation_lock);
907 
908 	pr_debug("SPC-3 PR [%s] Service Action: APTPL RESERVE created"
909 		" new reservation holder TYPE: %s ALL_TG_PT: %d\n",
910 		tpg->se_tpg_tfo->get_fabric_name(),
911 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
912 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
913 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
914 		tpg->se_tpg_tfo->get_fabric_name(), node_acl->initiatorname,
915 		(prf_isid) ? &i_buf[0] : "");
916 }
917 
918 static void __core_scsi3_add_registration(struct se_device *, struct se_node_acl *,
919 				struct t10_pr_registration *, int, int);
920 
921 static int __core_scsi3_check_aptpl_registration(
922 	struct se_device *dev,
923 	struct se_portal_group *tpg,
924 	struct se_lun *lun,
925 	u32 target_lun,
926 	struct se_node_acl *nacl,
927 	struct se_dev_entry *deve)
928 {
929 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
930 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
931 	unsigned char i_port[PR_APTPL_MAX_IPORT_LEN];
932 	unsigned char t_port[PR_APTPL_MAX_TPORT_LEN];
933 	u16 tpgt;
934 
935 	memset(i_port, 0, PR_APTPL_MAX_IPORT_LEN);
936 	memset(t_port, 0, PR_APTPL_MAX_TPORT_LEN);
937 	/*
938 	 * Copy Initiator Port information from struct se_node_acl
939 	 */
940 	snprintf(i_port, PR_APTPL_MAX_IPORT_LEN, "%s", nacl->initiatorname);
941 	snprintf(t_port, PR_APTPL_MAX_TPORT_LEN, "%s",
942 			tpg->se_tpg_tfo->tpg_get_wwn(tpg));
943 	tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
944 	/*
945 	 * Look for the matching registrations+reservation from those
946 	 * created from APTPL metadata.  Note that multiple registrations
947 	 * may exist for fabrics that use ISIDs in their SCSI Initiator Port
948 	 * TransportIDs.
949 	 */
950 	spin_lock(&pr_tmpl->aptpl_reg_lock);
951 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
952 				pr_reg_aptpl_list) {
953 		if (!strcmp(pr_reg->pr_iport, i_port) &&
954 		     (pr_reg->pr_res_mapped_lun == deve->mapped_lun) &&
955 		    !(strcmp(pr_reg->pr_tport, t_port)) &&
956 		     (pr_reg->pr_reg_tpgt == tpgt) &&
957 		     (pr_reg->pr_aptpl_target_lun == target_lun)) {
958 
959 			pr_reg->pr_reg_nacl = nacl;
960 			pr_reg->pr_reg_deve = deve;
961 			pr_reg->pr_reg_tg_pt_lun = lun;
962 
963 			list_del(&pr_reg->pr_reg_aptpl_list);
964 			spin_unlock(&pr_tmpl->aptpl_reg_lock);
965 			/*
966 			 * At this point all of the pointers in *pr_reg will
967 			 * be setup, so go ahead and add the registration.
968 			 */
969 
970 			__core_scsi3_add_registration(dev, nacl, pr_reg, 0, 0);
971 			/*
972 			 * If this registration is the reservation holder,
973 			 * make that happen now..
974 			 */
975 			if (pr_reg->pr_res_holder)
976 				core_scsi3_aptpl_reserve(dev, tpg,
977 						nacl, pr_reg);
978 			/*
979 			 * Reenable pr_aptpl_active to accept new metadata
980 			 * updates once the SCSI device is active again..
981 			 */
982 			spin_lock(&pr_tmpl->aptpl_reg_lock);
983 			pr_tmpl->pr_aptpl_active = 1;
984 		}
985 	}
986 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
987 
988 	return 0;
989 }
990 
991 int core_scsi3_check_aptpl_registration(
992 	struct se_device *dev,
993 	struct se_portal_group *tpg,
994 	struct se_lun *lun,
995 	struct se_lun_acl *lun_acl)
996 {
997 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
998 	struct se_node_acl *nacl = lun_acl->se_lun_nacl;
999 	struct se_dev_entry *deve = nacl->device_list[lun_acl->mapped_lun];
1000 
1001 	if (su_dev->t10_pr.res_type != SPC3_PERSISTENT_RESERVATIONS)
1002 		return 0;
1003 
1004 	return __core_scsi3_check_aptpl_registration(dev, tpg, lun,
1005 				lun->unpacked_lun, nacl, deve);
1006 }
1007 
1008 static void __core_scsi3_dump_registration(
1009 	struct target_core_fabric_ops *tfo,
1010 	struct se_device *dev,
1011 	struct se_node_acl *nacl,
1012 	struct t10_pr_registration *pr_reg,
1013 	int register_type)
1014 {
1015 	struct se_portal_group *se_tpg = nacl->se_tpg;
1016 	char i_buf[PR_REG_ISID_ID_LEN];
1017 	int prf_isid;
1018 
1019 	memset(&i_buf[0], 0, PR_REG_ISID_ID_LEN);
1020 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1021 				PR_REG_ISID_ID_LEN);
1022 
1023 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
1024 		" Node: %s%s\n", tfo->get_fabric_name(), (register_type == 2) ?
1025 		"_AND_MOVE" : (register_type == 1) ?
1026 		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname,
1027 		(prf_isid) ? i_buf : "");
1028 	pr_debug("SPC-3 PR [%s] registration on Target Port: %s,0x%04x\n",
1029 		 tfo->get_fabric_name(), tfo->tpg_get_wwn(se_tpg),
1030 		tfo->tpg_get_tag(se_tpg));
1031 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1032 		" Port(s)\n",  tfo->get_fabric_name(),
1033 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1034 		dev->transport->name);
1035 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1036 		" 0x%08x  APTPL: %d\n", tfo->get_fabric_name(),
1037 		pr_reg->pr_res_key, pr_reg->pr_res_generation,
1038 		pr_reg->pr_reg_aptpl);
1039 }
1040 
1041 /*
1042  * this function can be called with struct se_device->dev_reservation_lock
1043  * when register_move = 1
1044  */
1045 static void __core_scsi3_add_registration(
1046 	struct se_device *dev,
1047 	struct se_node_acl *nacl,
1048 	struct t10_pr_registration *pr_reg,
1049 	int register_type,
1050 	int register_move)
1051 {
1052 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1053 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
1054 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1055 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1056 
1057 	/*
1058 	 * Increment PRgeneration counter for struct se_device upon a successful
1059 	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
1060 	 *
1061 	 * Also, when register_move = 1 for PROUT REGISTER_AND_MOVE service
1062 	 * action, the struct se_device->dev_reservation_lock will already be held,
1063 	 * so we do not call core_scsi3_pr_generation() which grabs the lock
1064 	 * for the REGISTER.
1065 	 */
1066 	pr_reg->pr_res_generation = (register_move) ?
1067 			su_dev->t10_pr.pr_generation++ :
1068 			core_scsi3_pr_generation(dev);
1069 
1070 	spin_lock(&pr_tmpl->registration_lock);
1071 	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
1072 	pr_reg->pr_reg_deve->def_pr_registered = 1;
1073 
1074 	__core_scsi3_dump_registration(tfo, dev, nacl, pr_reg, register_type);
1075 	spin_unlock(&pr_tmpl->registration_lock);
1076 	/*
1077 	 * Skip extra processing for ALL_TG_PT=0 or REGISTER_AND_MOVE.
1078 	 */
1079 	if (!pr_reg->pr_reg_all_tg_pt || register_move)
1080 		return;
1081 	/*
1082 	 * Walk pr_reg->pr_reg_atp_list and add registrations for ALL_TG_PT=1
1083 	 * allocated in __core_scsi3_alloc_registration()
1084 	 */
1085 	list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1086 			&pr_reg->pr_reg_atp_list, pr_reg_atp_mem_list) {
1087 		list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1088 
1089 		pr_reg_tmp->pr_res_generation = core_scsi3_pr_generation(dev);
1090 
1091 		spin_lock(&pr_tmpl->registration_lock);
1092 		list_add_tail(&pr_reg_tmp->pr_reg_list,
1093 			      &pr_tmpl->registration_list);
1094 		pr_reg_tmp->pr_reg_deve->def_pr_registered = 1;
1095 
1096 		__core_scsi3_dump_registration(tfo, dev,
1097 				pr_reg_tmp->pr_reg_nacl, pr_reg_tmp,
1098 				register_type);
1099 		spin_unlock(&pr_tmpl->registration_lock);
1100 		/*
1101 		 * Drop configfs group dependency reference from
1102 		 * __core_scsi3_alloc_registration()
1103 		 */
1104 		core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1105 	}
1106 }
1107 
1108 static int core_scsi3_alloc_registration(
1109 	struct se_device *dev,
1110 	struct se_node_acl *nacl,
1111 	struct se_dev_entry *deve,
1112 	unsigned char *isid,
1113 	u64 sa_res_key,
1114 	int all_tg_pt,
1115 	int aptpl,
1116 	int register_type,
1117 	int register_move)
1118 {
1119 	struct t10_pr_registration *pr_reg;
1120 
1121 	pr_reg = __core_scsi3_alloc_registration(dev, nacl, deve, isid,
1122 			sa_res_key, all_tg_pt, aptpl);
1123 	if (!pr_reg)
1124 		return -EPERM;
1125 
1126 	__core_scsi3_add_registration(dev, nacl, pr_reg,
1127 			register_type, register_move);
1128 	return 0;
1129 }
1130 
1131 static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
1132 	struct se_device *dev,
1133 	struct se_node_acl *nacl,
1134 	unsigned char *isid)
1135 {
1136 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1137 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
1138 	struct se_portal_group *tpg;
1139 
1140 	spin_lock(&pr_tmpl->registration_lock);
1141 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1142 			&pr_tmpl->registration_list, pr_reg_list) {
1143 		/*
1144 		 * First look for a matching struct se_node_acl
1145 		 */
1146 		if (pr_reg->pr_reg_nacl != nacl)
1147 			continue;
1148 
1149 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1150 		/*
1151 		 * If this registration does NOT contain a fabric provided
1152 		 * ISID, then we have found a match.
1153 		 */
1154 		if (!pr_reg->isid_present_at_reg) {
1155 			/*
1156 			 * Determine if this SCSI device server requires that
1157 			 * SCSI Intiatior TransportID w/ ISIDs is enforced
1158 			 * for fabric modules (iSCSI) requiring them.
1159 			 */
1160 			if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1161 				if (dev->se_sub_dev->se_dev_attrib.enforce_pr_isids)
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 		/*
1170 		 * If the *pr_reg contains a fabric defined ISID for multi-value
1171 		 * SCSI Initiator Port TransportIDs, then we expect a valid
1172 		 * matching ISID to be provided by the local SCSI Initiator Port.
1173 		 */
1174 		if (!isid)
1175 			continue;
1176 		if (strcmp(isid, pr_reg->pr_reg_isid))
1177 			continue;
1178 
1179 		atomic_inc(&pr_reg->pr_res_holders);
1180 		smp_mb__after_atomic_inc();
1181 		spin_unlock(&pr_tmpl->registration_lock);
1182 		return pr_reg;
1183 	}
1184 	spin_unlock(&pr_tmpl->registration_lock);
1185 
1186 	return NULL;
1187 }
1188 
1189 static struct t10_pr_registration *core_scsi3_locate_pr_reg(
1190 	struct se_device *dev,
1191 	struct se_node_acl *nacl,
1192 	struct se_session *sess)
1193 {
1194 	struct se_portal_group *tpg = nacl->se_tpg;
1195 	unsigned char buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
1196 
1197 	if (tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
1198 		memset(&buf[0], 0, PR_REG_ISID_LEN);
1199 		tpg->se_tpg_tfo->sess_get_initiator_sid(sess, &buf[0],
1200 					PR_REG_ISID_LEN);
1201 		isid_ptr = &buf[0];
1202 	}
1203 
1204 	return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
1205 }
1206 
1207 static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
1208 {
1209 	atomic_dec(&pr_reg->pr_res_holders);
1210 	smp_mb__after_atomic_dec();
1211 }
1212 
1213 static int core_scsi3_check_implict_release(
1214 	struct se_device *dev,
1215 	struct t10_pr_registration *pr_reg)
1216 {
1217 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
1218 	struct t10_pr_registration *pr_res_holder;
1219 	int ret = 0;
1220 
1221 	spin_lock(&dev->dev_reservation_lock);
1222 	pr_res_holder = dev->dev_pr_res_holder;
1223 	if (!pr_res_holder) {
1224 		spin_unlock(&dev->dev_reservation_lock);
1225 		return ret;
1226 	}
1227 	if (pr_res_holder == pr_reg) {
1228 		/*
1229 		 * Perform an implict RELEASE if the registration that
1230 		 * is being released is holding the reservation.
1231 		 *
1232 		 * From spc4r17, section 5.7.11.1:
1233 		 *
1234 		 * e) If the I_T nexus is the persistent reservation holder
1235 		 *    and the persistent reservation is not an all registrants
1236 		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
1237 		 *    service action or REGISTER AND  IGNORE EXISTING KEY
1238 		 *    service action with the SERVICE ACTION RESERVATION KEY
1239 		 *    field set to zero (see 5.7.11.3).
1240 		 */
1241 		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0);
1242 		ret = 1;
1243 		/*
1244 		 * For 'All Registrants' reservation types, all existing
1245 		 * registrations are still processed as reservation holders
1246 		 * in core_scsi3_pr_seq_non_holder() after the initial
1247 		 * reservation holder is implictly released here.
1248 		 */
1249 	} else if (pr_reg->pr_reg_all_tg_pt &&
1250 		  (!strcmp(pr_res_holder->pr_reg_nacl->initiatorname,
1251 			  pr_reg->pr_reg_nacl->initiatorname)) &&
1252 		  (pr_res_holder->pr_res_key == pr_reg->pr_res_key)) {
1253 		pr_err("SPC-3 PR: Unable to perform ALL_TG_PT=1"
1254 			" UNREGISTER while existing reservation with matching"
1255 			" key 0x%016Lx is present from another SCSI Initiator"
1256 			" Port\n", pr_reg->pr_res_key);
1257 		ret = -EPERM;
1258 	}
1259 	spin_unlock(&dev->dev_reservation_lock);
1260 
1261 	return ret;
1262 }
1263 
1264 /*
1265  * Called with struct t10_reservation->registration_lock held.
1266  */
1267 static void __core_scsi3_free_registration(
1268 	struct se_device *dev,
1269 	struct t10_pr_registration *pr_reg,
1270 	struct list_head *preempt_and_abort_list,
1271 	int dec_holders)
1272 {
1273 	struct target_core_fabric_ops *tfo =
1274 			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
1275 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1276 	char i_buf[PR_REG_ISID_ID_LEN];
1277 	int prf_isid;
1278 
1279 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1280 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
1281 				PR_REG_ISID_ID_LEN);
1282 
1283 	pr_reg->pr_reg_deve->def_pr_registered = 0;
1284 	pr_reg->pr_reg_deve->pr_res_key = 0;
1285 	list_del(&pr_reg->pr_reg_list);
1286 	/*
1287 	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
1288 	 * so call core_scsi3_put_pr_reg() to decrement our reference.
1289 	 */
1290 	if (dec_holders)
1291 		core_scsi3_put_pr_reg(pr_reg);
1292 	/*
1293 	 * Wait until all reference from any other I_T nexuses for this
1294 	 * *pr_reg have been released.  Because list_del() is called above,
1295 	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
1296 	 * count back to zero, and we release *pr_reg.
1297 	 */
1298 	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
1299 		spin_unlock(&pr_tmpl->registration_lock);
1300 		pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
1301 				tfo->get_fabric_name());
1302 		cpu_relax();
1303 		spin_lock(&pr_tmpl->registration_lock);
1304 	}
1305 
1306 	pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
1307 		" Node: %s%s\n", tfo->get_fabric_name(),
1308 		pr_reg->pr_reg_nacl->initiatorname,
1309 		(prf_isid) ? &i_buf[0] : "");
1310 	pr_debug("SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
1311 		" Port(s)\n", tfo->get_fabric_name(),
1312 		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
1313 		dev->transport->name);
1314 	pr_debug("SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
1315 		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
1316 		pr_reg->pr_res_generation);
1317 
1318 	if (!preempt_and_abort_list) {
1319 		pr_reg->pr_reg_deve = NULL;
1320 		pr_reg->pr_reg_nacl = NULL;
1321 		kfree(pr_reg->pr_aptpl_buf);
1322 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1323 		return;
1324 	}
1325 	/*
1326 	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
1327 	 * are released once the ABORT_TASK_SET has completed..
1328 	 */
1329 	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
1330 }
1331 
1332 void core_scsi3_free_pr_reg_from_nacl(
1333 	struct se_device *dev,
1334 	struct se_node_acl *nacl)
1335 {
1336 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1337 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1338 	/*
1339 	 * If the passed se_node_acl matches the reservation holder,
1340 	 * release the reservation.
1341 	 */
1342 	spin_lock(&dev->dev_reservation_lock);
1343 	pr_res_holder = dev->dev_pr_res_holder;
1344 	if ((pr_res_holder != NULL) &&
1345 	    (pr_res_holder->pr_reg_nacl == nacl))
1346 		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0);
1347 	spin_unlock(&dev->dev_reservation_lock);
1348 	/*
1349 	 * Release any registration associated with the struct se_node_acl.
1350 	 */
1351 	spin_lock(&pr_tmpl->registration_lock);
1352 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1353 			&pr_tmpl->registration_list, pr_reg_list) {
1354 
1355 		if (pr_reg->pr_reg_nacl != nacl)
1356 			continue;
1357 
1358 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1359 	}
1360 	spin_unlock(&pr_tmpl->registration_lock);
1361 }
1362 
1363 void core_scsi3_free_all_registrations(
1364 	struct se_device *dev)
1365 {
1366 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
1367 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_res_holder;
1368 
1369 	spin_lock(&dev->dev_reservation_lock);
1370 	pr_res_holder = dev->dev_pr_res_holder;
1371 	if (pr_res_holder != NULL) {
1372 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
1373 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
1374 				pr_res_holder, 0);
1375 	}
1376 	spin_unlock(&dev->dev_reservation_lock);
1377 
1378 	spin_lock(&pr_tmpl->registration_lock);
1379 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
1380 			&pr_tmpl->registration_list, pr_reg_list) {
1381 
1382 		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
1383 	}
1384 	spin_unlock(&pr_tmpl->registration_lock);
1385 
1386 	spin_lock(&pr_tmpl->aptpl_reg_lock);
1387 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, &pr_tmpl->aptpl_reg_list,
1388 				pr_reg_aptpl_list) {
1389 		list_del(&pr_reg->pr_reg_aptpl_list);
1390 		kfree(pr_reg->pr_aptpl_buf);
1391 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
1392 	}
1393 	spin_unlock(&pr_tmpl->aptpl_reg_lock);
1394 }
1395 
1396 static int core_scsi3_tpg_depend_item(struct se_portal_group *tpg)
1397 {
1398 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1399 			&tpg->tpg_group.cg_item);
1400 }
1401 
1402 static void core_scsi3_tpg_undepend_item(struct se_portal_group *tpg)
1403 {
1404 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1405 			&tpg->tpg_group.cg_item);
1406 
1407 	atomic_dec(&tpg->tpg_pr_ref_count);
1408 	smp_mb__after_atomic_dec();
1409 }
1410 
1411 static int core_scsi3_nodeacl_depend_item(struct se_node_acl *nacl)
1412 {
1413 	struct se_portal_group *tpg = nacl->se_tpg;
1414 
1415 	if (nacl->dynamic_node_acl)
1416 		return 0;
1417 
1418 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1419 			&nacl->acl_group.cg_item);
1420 }
1421 
1422 static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
1423 {
1424 	struct se_portal_group *tpg = nacl->se_tpg;
1425 
1426 	if (nacl->dynamic_node_acl) {
1427 		atomic_dec(&nacl->acl_pr_ref_count);
1428 		smp_mb__after_atomic_dec();
1429 		return;
1430 	}
1431 
1432 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1433 			&nacl->acl_group.cg_item);
1434 
1435 	atomic_dec(&nacl->acl_pr_ref_count);
1436 	smp_mb__after_atomic_dec();
1437 }
1438 
1439 static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
1440 {
1441 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1442 	struct se_node_acl *nacl;
1443 	struct se_portal_group *tpg;
1444 	/*
1445 	 * For nacl->dynamic_node_acl=1
1446 	 */
1447 	if (!lun_acl)
1448 		return 0;
1449 
1450 	nacl = lun_acl->se_lun_nacl;
1451 	tpg = nacl->se_tpg;
1452 
1453 	return configfs_depend_item(tpg->se_tpg_tfo->tf_subsys,
1454 			&lun_acl->se_lun_group.cg_item);
1455 }
1456 
1457 static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
1458 {
1459 	struct se_lun_acl *lun_acl = se_deve->se_lun_acl;
1460 	struct se_node_acl *nacl;
1461 	struct se_portal_group *tpg;
1462 	/*
1463 	 * For nacl->dynamic_node_acl=1
1464 	 */
1465 	if (!lun_acl) {
1466 		atomic_dec(&se_deve->pr_ref_count);
1467 		smp_mb__after_atomic_dec();
1468 		return;
1469 	}
1470 	nacl = lun_acl->se_lun_nacl;
1471 	tpg = nacl->se_tpg;
1472 
1473 	configfs_undepend_item(tpg->se_tpg_tfo->tf_subsys,
1474 			&lun_acl->se_lun_group.cg_item);
1475 
1476 	atomic_dec(&se_deve->pr_ref_count);
1477 	smp_mb__after_atomic_dec();
1478 }
1479 
1480 static int core_scsi3_decode_spec_i_port(
1481 	struct se_cmd *cmd,
1482 	struct se_portal_group *tpg,
1483 	unsigned char *l_isid,
1484 	u64 sa_res_key,
1485 	int all_tg_pt,
1486 	int aptpl)
1487 {
1488 	struct se_device *dev = cmd->se_dev;
1489 	struct se_port *tmp_port;
1490 	struct se_portal_group *dest_tpg = NULL, *tmp_tpg;
1491 	struct se_session *se_sess = cmd->se_sess;
1492 	struct se_node_acl *dest_node_acl = NULL;
1493 	struct se_dev_entry *dest_se_deve = NULL, *local_se_deve;
1494 	struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e;
1495 	struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe;
1496 	LIST_HEAD(tid_dest_list);
1497 	struct pr_transport_id_holder *tidh_new, *tidh, *tidh_tmp;
1498 	struct target_core_fabric_ops *tmp_tf_ops;
1499 	unsigned char *buf;
1500 	unsigned char *ptr, *i_str = NULL, proto_ident, tmp_proto_ident;
1501 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
1502 	u32 tpdl, tid_len = 0;
1503 	int ret, dest_local_nexus, prf_isid;
1504 	u32 dest_rtpi = 0;
1505 
1506 	memset(dest_iport, 0, 64);
1507 
1508 	local_se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
1509 	/*
1510 	 * Allocate a struct pr_transport_id_holder and setup the
1511 	 * local_node_acl and local_se_deve pointers and add to
1512 	 * struct list_head tid_dest_list for add registration
1513 	 * processing in the loop of tid_dest_list below.
1514 	 */
1515 	tidh_new = kzalloc(sizeof(struct pr_transport_id_holder), GFP_KERNEL);
1516 	if (!tidh_new) {
1517 		pr_err("Unable to allocate tidh_new\n");
1518 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1519 		return -EINVAL;
1520 	}
1521 	INIT_LIST_HEAD(&tidh_new->dest_list);
1522 	tidh_new->dest_tpg = tpg;
1523 	tidh_new->dest_node_acl = se_sess->se_node_acl;
1524 	tidh_new->dest_se_deve = local_se_deve;
1525 
1526 	local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1527 				se_sess->se_node_acl, local_se_deve, l_isid,
1528 				sa_res_key, all_tg_pt, aptpl);
1529 	if (!local_pr_reg) {
1530 		kfree(tidh_new);
1531 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1532 		return -ENOMEM;
1533 	}
1534 	tidh_new->dest_pr_reg = local_pr_reg;
1535 	/*
1536 	 * The local I_T nexus does not hold any configfs dependances,
1537 	 * so we set tid_h->dest_local_nexus=1 to prevent the
1538 	 * configfs_undepend_item() calls in the tid_dest_list loops below.
1539 	 */
1540 	tidh_new->dest_local_nexus = 1;
1541 	list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1542 
1543 	buf = transport_kmap_data_sg(cmd);
1544 	/*
1545 	 * For a PERSISTENT RESERVE OUT specify initiator ports payload,
1546 	 * first extract TransportID Parameter Data Length, and make sure
1547 	 * the value matches up to the SCSI expected data transfer length.
1548 	 */
1549 	tpdl = (buf[24] & 0xff) << 24;
1550 	tpdl |= (buf[25] & 0xff) << 16;
1551 	tpdl |= (buf[26] & 0xff) << 8;
1552 	tpdl |= buf[27] & 0xff;
1553 
1554 	if ((tpdl + 28) != cmd->data_length) {
1555 		pr_err("SPC-3 PR: Illegal tpdl: %u + 28 byte header"
1556 			" does not equal CDB data_length: %u\n", tpdl,
1557 			cmd->data_length);
1558 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1559 		ret = -EINVAL;
1560 		goto out;
1561 	}
1562 	/*
1563 	 * Start processing the received transport IDs using the
1564 	 * receiving I_T Nexus portal's fabric dependent methods to
1565 	 * obtain the SCSI Initiator Port/Device Identifiers.
1566 	 */
1567 	ptr = &buf[28];
1568 
1569 	while (tpdl > 0) {
1570 		proto_ident = (ptr[0] & 0x0f);
1571 		dest_tpg = NULL;
1572 
1573 		spin_lock(&dev->se_port_lock);
1574 		list_for_each_entry(tmp_port, &dev->dev_sep_list, sep_list) {
1575 			tmp_tpg = tmp_port->sep_tpg;
1576 			if (!tmp_tpg)
1577 				continue;
1578 			tmp_tf_ops = tmp_tpg->se_tpg_tfo;
1579 			if (!tmp_tf_ops)
1580 				continue;
1581 			if (!tmp_tf_ops->get_fabric_proto_ident ||
1582 			    !tmp_tf_ops->tpg_parse_pr_out_transport_id)
1583 				continue;
1584 			/*
1585 			 * Look for the matching proto_ident provided by
1586 			 * the received TransportID
1587 			 */
1588 			tmp_proto_ident = tmp_tf_ops->get_fabric_proto_ident(tmp_tpg);
1589 			if (tmp_proto_ident != proto_ident)
1590 				continue;
1591 			dest_rtpi = tmp_port->sep_rtpi;
1592 
1593 			i_str = tmp_tf_ops->tpg_parse_pr_out_transport_id(
1594 					tmp_tpg, (const char *)ptr, &tid_len,
1595 					&iport_ptr);
1596 			if (!i_str)
1597 				continue;
1598 
1599 			atomic_inc(&tmp_tpg->tpg_pr_ref_count);
1600 			smp_mb__after_atomic_inc();
1601 			spin_unlock(&dev->se_port_lock);
1602 
1603 			ret = core_scsi3_tpg_depend_item(tmp_tpg);
1604 			if (ret != 0) {
1605 				pr_err(" core_scsi3_tpg_depend_item()"
1606 					" for tmp_tpg\n");
1607 				atomic_dec(&tmp_tpg->tpg_pr_ref_count);
1608 				smp_mb__after_atomic_dec();
1609 				cmd->scsi_sense_reason =
1610 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1611 				ret = -EINVAL;
1612 				goto out;
1613 			}
1614 			/*
1615 			 * Locate the desination initiator ACL to be registered
1616 			 * from the decoded fabric module specific TransportID
1617 			 * at *i_str.
1618 			 */
1619 			spin_lock_irq(&tmp_tpg->acl_node_lock);
1620 			dest_node_acl = __core_tpg_get_initiator_node_acl(
1621 						tmp_tpg, i_str);
1622 			if (dest_node_acl) {
1623 				atomic_inc(&dest_node_acl->acl_pr_ref_count);
1624 				smp_mb__after_atomic_inc();
1625 			}
1626 			spin_unlock_irq(&tmp_tpg->acl_node_lock);
1627 
1628 			if (!dest_node_acl) {
1629 				core_scsi3_tpg_undepend_item(tmp_tpg);
1630 				spin_lock(&dev->se_port_lock);
1631 				continue;
1632 			}
1633 
1634 			ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
1635 			if (ret != 0) {
1636 				pr_err("configfs_depend_item() failed"
1637 					" for dest_node_acl->acl_group\n");
1638 				atomic_dec(&dest_node_acl->acl_pr_ref_count);
1639 				smp_mb__after_atomic_dec();
1640 				core_scsi3_tpg_undepend_item(tmp_tpg);
1641 				cmd->scsi_sense_reason =
1642 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1643 				ret = -EINVAL;
1644 				goto out;
1645 			}
1646 
1647 			dest_tpg = tmp_tpg;
1648 			pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node:"
1649 				" %s Port RTPI: %hu\n",
1650 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1651 				dest_node_acl->initiatorname, dest_rtpi);
1652 
1653 			spin_lock(&dev->se_port_lock);
1654 			break;
1655 		}
1656 		spin_unlock(&dev->se_port_lock);
1657 
1658 		if (!dest_tpg) {
1659 			pr_err("SPC-3 PR SPEC_I_PT: Unable to locate"
1660 					" dest_tpg\n");
1661 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1662 			ret = -EINVAL;
1663 			goto out;
1664 		}
1665 
1666 		pr_debug("SPC-3 PR SPEC_I_PT: Got %s data_length: %u tpdl: %u"
1667 			" tid_len: %d for %s + %s\n",
1668 			dest_tpg->se_tpg_tfo->get_fabric_name(), cmd->data_length,
1669 			tpdl, tid_len, i_str, iport_ptr);
1670 
1671 		if (tid_len > tpdl) {
1672 			pr_err("SPC-3 PR SPEC_I_PT: Illegal tid_len:"
1673 				" %u for Transport ID: %s\n", tid_len, ptr);
1674 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1675 			core_scsi3_tpg_undepend_item(dest_tpg);
1676 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1677 			ret = -EINVAL;
1678 			goto out;
1679 		}
1680 		/*
1681 		 * Locate the desintation struct se_dev_entry pointer for matching
1682 		 * RELATIVE TARGET PORT IDENTIFIER on the receiving I_T Nexus
1683 		 * Target Port.
1684 		 */
1685 		dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl,
1686 					dest_rtpi);
1687 		if (!dest_se_deve) {
1688 			pr_err("Unable to locate %s dest_se_deve"
1689 				" from destination RTPI: %hu\n",
1690 				dest_tpg->se_tpg_tfo->get_fabric_name(),
1691 				dest_rtpi);
1692 
1693 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1694 			core_scsi3_tpg_undepend_item(dest_tpg);
1695 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1696 			ret = -EINVAL;
1697 			goto out;
1698 		}
1699 
1700 		ret = core_scsi3_lunacl_depend_item(dest_se_deve);
1701 		if (ret < 0) {
1702 			pr_err("core_scsi3_lunacl_depend_item()"
1703 					" failed\n");
1704 			atomic_dec(&dest_se_deve->pr_ref_count);
1705 			smp_mb__after_atomic_dec();
1706 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1707 			core_scsi3_tpg_undepend_item(dest_tpg);
1708 			cmd->scsi_sense_reason =
1709 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1710 			ret = -EINVAL;
1711 			goto out;
1712 		}
1713 
1714 		pr_debug("SPC-3 PR SPEC_I_PT: Located %s Node: %s"
1715 			" dest_se_deve mapped_lun: %u\n",
1716 			dest_tpg->se_tpg_tfo->get_fabric_name(),
1717 			dest_node_acl->initiatorname, dest_se_deve->mapped_lun);
1718 
1719 		/*
1720 		 * Skip any TransportIDs that already have a registration for
1721 		 * this target port.
1722 		 */
1723 		pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
1724 					iport_ptr);
1725 		if (pr_reg_e) {
1726 			core_scsi3_put_pr_reg(pr_reg_e);
1727 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1728 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1729 			core_scsi3_tpg_undepend_item(dest_tpg);
1730 			ptr += tid_len;
1731 			tpdl -= tid_len;
1732 			tid_len = 0;
1733 			continue;
1734 		}
1735 		/*
1736 		 * Allocate a struct pr_transport_id_holder and setup
1737 		 * the dest_node_acl and dest_se_deve pointers for the
1738 		 * loop below.
1739 		 */
1740 		tidh_new = kzalloc(sizeof(struct pr_transport_id_holder),
1741 				GFP_KERNEL);
1742 		if (!tidh_new) {
1743 			pr_err("Unable to allocate tidh_new\n");
1744 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1745 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1746 			core_scsi3_tpg_undepend_item(dest_tpg);
1747 			cmd->scsi_sense_reason =
1748 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1749 			ret = -ENOMEM;
1750 			goto out;
1751 		}
1752 		INIT_LIST_HEAD(&tidh_new->dest_list);
1753 		tidh_new->dest_tpg = dest_tpg;
1754 		tidh_new->dest_node_acl = dest_node_acl;
1755 		tidh_new->dest_se_deve = dest_se_deve;
1756 
1757 		/*
1758 		 * Allocate, but do NOT add the registration for the
1759 		 * TransportID referenced SCSI Initiator port.  This
1760 		 * done because of the following from spc4r17 in section
1761 		 * 6.14.3 wrt SPEC_I_PT:
1762 		 *
1763 		 * "If a registration fails for any initiator port (e.g., if th
1764 		 * logical unit does not have enough resources available to
1765 		 * hold the registration information), no registrations shall be
1766 		 * made, and the command shall be terminated with
1767 		 * CHECK CONDITION status."
1768 		 *
1769 		 * That means we call __core_scsi3_alloc_registration() here,
1770 		 * and then call __core_scsi3_add_registration() in the
1771 		 * 2nd loop which will never fail.
1772 		 */
1773 		dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
1774 				dest_node_acl, dest_se_deve, iport_ptr,
1775 				sa_res_key, all_tg_pt, aptpl);
1776 		if (!dest_pr_reg) {
1777 			core_scsi3_lunacl_undepend_item(dest_se_deve);
1778 			core_scsi3_nodeacl_undepend_item(dest_node_acl);
1779 			core_scsi3_tpg_undepend_item(dest_tpg);
1780 			kfree(tidh_new);
1781 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
1782 			ret = -EINVAL;
1783 			goto out;
1784 		}
1785 		tidh_new->dest_pr_reg = dest_pr_reg;
1786 		list_add_tail(&tidh_new->dest_list, &tid_dest_list);
1787 
1788 		ptr += tid_len;
1789 		tpdl -= tid_len;
1790 		tid_len = 0;
1791 
1792 	}
1793 
1794 	transport_kunmap_data_sg(cmd);
1795 
1796 	/*
1797 	 * Go ahead and create a registrations from tid_dest_list for the
1798 	 * SPEC_I_PT provided TransportID for the *tidh referenced dest_node_acl
1799 	 * and dest_se_deve.
1800 	 *
1801 	 * The SA Reservation Key from the PROUT is set for the
1802 	 * registration, and ALL_TG_PT is also passed.  ALL_TG_PT=1
1803 	 * means that the TransportID Initiator port will be
1804 	 * registered on all of the target ports in the SCSI target device
1805 	 * ALL_TG_PT=0 means the registration will only be for the
1806 	 * SCSI target port the PROUT REGISTER with SPEC_I_PT=1
1807 	 * was received.
1808 	 */
1809 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1810 		dest_tpg = tidh->dest_tpg;
1811 		dest_node_acl = tidh->dest_node_acl;
1812 		dest_se_deve = tidh->dest_se_deve;
1813 		dest_pr_reg = tidh->dest_pr_reg;
1814 		dest_local_nexus = tidh->dest_local_nexus;
1815 
1816 		list_del(&tidh->dest_list);
1817 		kfree(tidh);
1818 
1819 		memset(i_buf, 0, PR_REG_ISID_ID_LEN);
1820 		prf_isid = core_pr_dump_initiator_port(dest_pr_reg, &i_buf[0],
1821 						PR_REG_ISID_ID_LEN);
1822 
1823 		__core_scsi3_add_registration(cmd->se_dev, dest_node_acl,
1824 					dest_pr_reg, 0, 0);
1825 
1826 		pr_debug("SPC-3 PR [%s] SPEC_I_PT: Successfully"
1827 			" registered Transport ID for Node: %s%s Mapped LUN:"
1828 			" %u\n", dest_tpg->se_tpg_tfo->get_fabric_name(),
1829 			dest_node_acl->initiatorname, (prf_isid) ?
1830 			&i_buf[0] : "", dest_se_deve->mapped_lun);
1831 
1832 		if (dest_local_nexus)
1833 			continue;
1834 
1835 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1836 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1837 		core_scsi3_tpg_undepend_item(dest_tpg);
1838 	}
1839 
1840 	return 0;
1841 out:
1842 	transport_kunmap_data_sg(cmd);
1843 	/*
1844 	 * For the failure case, release everything from tid_dest_list
1845 	 * including *dest_pr_reg and the configfs dependances..
1846 	 */
1847 	list_for_each_entry_safe(tidh, tidh_tmp, &tid_dest_list, dest_list) {
1848 		dest_tpg = tidh->dest_tpg;
1849 		dest_node_acl = tidh->dest_node_acl;
1850 		dest_se_deve = tidh->dest_se_deve;
1851 		dest_pr_reg = tidh->dest_pr_reg;
1852 		dest_local_nexus = tidh->dest_local_nexus;
1853 
1854 		list_del(&tidh->dest_list);
1855 		kfree(tidh);
1856 		/*
1857 		 * Release any extra ALL_TG_PT=1 registrations for
1858 		 * the SPEC_I_PT=1 case.
1859 		 */
1860 		list_for_each_entry_safe(pr_reg_tmp, pr_reg_tmp_safe,
1861 				&dest_pr_reg->pr_reg_atp_list,
1862 				pr_reg_atp_mem_list) {
1863 			list_del(&pr_reg_tmp->pr_reg_atp_mem_list);
1864 			core_scsi3_lunacl_undepend_item(pr_reg_tmp->pr_reg_deve);
1865 			kmem_cache_free(t10_pr_reg_cache, pr_reg_tmp);
1866 		}
1867 
1868 		kfree(dest_pr_reg->pr_aptpl_buf);
1869 		kmem_cache_free(t10_pr_reg_cache, dest_pr_reg);
1870 
1871 		if (dest_local_nexus)
1872 			continue;
1873 
1874 		core_scsi3_lunacl_undepend_item(dest_se_deve);
1875 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
1876 		core_scsi3_tpg_undepend_item(dest_tpg);
1877 	}
1878 	return ret;
1879 }
1880 
1881 /*
1882  * Called with struct se_device->dev_reservation_lock held
1883  */
1884 static int __core_scsi3_update_aptpl_buf(
1885 	struct se_device *dev,
1886 	unsigned char *buf,
1887 	u32 pr_aptpl_buf_len,
1888 	int clear_aptpl_metadata)
1889 {
1890 	struct se_lun *lun;
1891 	struct se_portal_group *tpg;
1892 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1893 	struct t10_pr_registration *pr_reg;
1894 	unsigned char tmp[512], isid_buf[32];
1895 	ssize_t len = 0;
1896 	int reg_count = 0;
1897 
1898 	memset(buf, 0, pr_aptpl_buf_len);
1899 	/*
1900 	 * Called to clear metadata once APTPL has been deactivated.
1901 	 */
1902 	if (clear_aptpl_metadata) {
1903 		snprintf(buf, pr_aptpl_buf_len,
1904 				"No Registrations or Reservations\n");
1905 		return 0;
1906 	}
1907 	/*
1908 	 * Walk the registration list..
1909 	 */
1910 	spin_lock(&su_dev->t10_pr.registration_lock);
1911 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
1912 			pr_reg_list) {
1913 
1914 		tmp[0] = '\0';
1915 		isid_buf[0] = '\0';
1916 		tpg = pr_reg->pr_reg_nacl->se_tpg;
1917 		lun = pr_reg->pr_reg_tg_pt_lun;
1918 		/*
1919 		 * Write out any ISID value to APTPL metadata that was included
1920 		 * in the original registration.
1921 		 */
1922 		if (pr_reg->isid_present_at_reg)
1923 			snprintf(isid_buf, 32, "initiator_sid=%s\n",
1924 					pr_reg->pr_reg_isid);
1925 		/*
1926 		 * Include special metadata if the pr_reg matches the
1927 		 * reservation holder.
1928 		 */
1929 		if (dev->dev_pr_res_holder == pr_reg) {
1930 			snprintf(tmp, 512, "PR_REG_START: %d"
1931 				"\ninitiator_fabric=%s\n"
1932 				"initiator_node=%s\n%s"
1933 				"sa_res_key=%llu\n"
1934 				"res_holder=1\nres_type=%02x\n"
1935 				"res_scope=%02x\nres_all_tg_pt=%d\n"
1936 				"mapped_lun=%u\n", reg_count,
1937 				tpg->se_tpg_tfo->get_fabric_name(),
1938 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1939 				pr_reg->pr_res_key, pr_reg->pr_res_type,
1940 				pr_reg->pr_res_scope, pr_reg->pr_reg_all_tg_pt,
1941 				pr_reg->pr_res_mapped_lun);
1942 		} else {
1943 			snprintf(tmp, 512, "PR_REG_START: %d\n"
1944 				"initiator_fabric=%s\ninitiator_node=%s\n%s"
1945 				"sa_res_key=%llu\nres_holder=0\n"
1946 				"res_all_tg_pt=%d\nmapped_lun=%u\n",
1947 				reg_count, tpg->se_tpg_tfo->get_fabric_name(),
1948 				pr_reg->pr_reg_nacl->initiatorname, isid_buf,
1949 				pr_reg->pr_res_key, pr_reg->pr_reg_all_tg_pt,
1950 				pr_reg->pr_res_mapped_lun);
1951 		}
1952 
1953 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1954 			pr_err("Unable to update renaming"
1955 				" APTPL metadata\n");
1956 			spin_unlock(&su_dev->t10_pr.registration_lock);
1957 			return -EMSGSIZE;
1958 		}
1959 		len += sprintf(buf+len, "%s", tmp);
1960 
1961 		/*
1962 		 * Include information about the associated SCSI target port.
1963 		 */
1964 		snprintf(tmp, 512, "target_fabric=%s\ntarget_node=%s\n"
1965 			"tpgt=%hu\nport_rtpi=%hu\ntarget_lun=%u\nPR_REG_END:"
1966 			" %d\n", tpg->se_tpg_tfo->get_fabric_name(),
1967 			tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1968 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1969 			lun->lun_sep->sep_rtpi, lun->unpacked_lun, reg_count);
1970 
1971 		if ((len + strlen(tmp) >= pr_aptpl_buf_len)) {
1972 			pr_err("Unable to update renaming"
1973 				" APTPL metadata\n");
1974 			spin_unlock(&su_dev->t10_pr.registration_lock);
1975 			return -EMSGSIZE;
1976 		}
1977 		len += sprintf(buf+len, "%s", tmp);
1978 		reg_count++;
1979 	}
1980 	spin_unlock(&su_dev->t10_pr.registration_lock);
1981 
1982 	if (!reg_count)
1983 		len += sprintf(buf+len, "No Registrations or Reservations");
1984 
1985 	return 0;
1986 }
1987 
1988 static int core_scsi3_update_aptpl_buf(
1989 	struct se_device *dev,
1990 	unsigned char *buf,
1991 	u32 pr_aptpl_buf_len,
1992 	int clear_aptpl_metadata)
1993 {
1994 	int ret;
1995 
1996 	spin_lock(&dev->dev_reservation_lock);
1997 	ret = __core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
1998 				clear_aptpl_metadata);
1999 	spin_unlock(&dev->dev_reservation_lock);
2000 
2001 	return ret;
2002 }
2003 
2004 /*
2005  * Called with struct se_device->aptpl_file_mutex held
2006  */
2007 static int __core_scsi3_write_aptpl_to_file(
2008 	struct se_device *dev,
2009 	unsigned char *buf,
2010 	u32 pr_aptpl_buf_len)
2011 {
2012 	struct t10_wwn *wwn = &dev->se_sub_dev->t10_wwn;
2013 	struct file *file;
2014 	struct iovec iov[1];
2015 	mm_segment_t old_fs;
2016 	int flags = O_RDWR | O_CREAT | O_TRUNC;
2017 	char path[512];
2018 	int ret;
2019 
2020 	memset(iov, 0, sizeof(struct iovec));
2021 	memset(path, 0, 512);
2022 
2023 	if (strlen(&wwn->unit_serial[0]) >= 512) {
2024 		pr_err("WWN value for struct se_device does not fit"
2025 			" into path buffer\n");
2026 		return -EMSGSIZE;
2027 	}
2028 
2029 	snprintf(path, 512, "/var/target/pr/aptpl_%s", &wwn->unit_serial[0]);
2030 	file = filp_open(path, flags, 0600);
2031 	if (IS_ERR(file) || !file || !file->f_dentry) {
2032 		pr_err("filp_open(%s) for APTPL metadata"
2033 			" failed\n", path);
2034 		return IS_ERR(file) ? PTR_ERR(file) : -ENOENT;
2035 	}
2036 
2037 	iov[0].iov_base = &buf[0];
2038 	if (!pr_aptpl_buf_len)
2039 		iov[0].iov_len = (strlen(&buf[0]) + 1); /* Add extra for NULL */
2040 	else
2041 		iov[0].iov_len = pr_aptpl_buf_len;
2042 
2043 	old_fs = get_fs();
2044 	set_fs(get_ds());
2045 	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
2046 	set_fs(old_fs);
2047 
2048 	if (ret < 0) {
2049 		pr_debug("Error writing APTPL metadata file: %s\n", path);
2050 		filp_close(file, NULL);
2051 		return -EIO;
2052 	}
2053 	filp_close(file, NULL);
2054 
2055 	return 0;
2056 }
2057 
2058 static int core_scsi3_update_and_write_aptpl(
2059 	struct se_device *dev,
2060 	unsigned char *in_buf,
2061 	u32 in_pr_aptpl_buf_len)
2062 {
2063 	unsigned char null_buf[64], *buf;
2064 	u32 pr_aptpl_buf_len;
2065 	int ret, clear_aptpl_metadata = 0;
2066 	/*
2067 	 * Can be called with a NULL pointer from PROUT service action CLEAR
2068 	 */
2069 	if (!in_buf) {
2070 		memset(null_buf, 0, 64);
2071 		buf = &null_buf[0];
2072 		/*
2073 		 * This will clear the APTPL metadata to:
2074 		 * "No Registrations or Reservations" status
2075 		 */
2076 		pr_aptpl_buf_len = 64;
2077 		clear_aptpl_metadata = 1;
2078 	} else {
2079 		buf = in_buf;
2080 		pr_aptpl_buf_len = in_pr_aptpl_buf_len;
2081 	}
2082 
2083 	ret = core_scsi3_update_aptpl_buf(dev, buf, pr_aptpl_buf_len,
2084 				clear_aptpl_metadata);
2085 	if (ret != 0)
2086 		return ret;
2087 	/*
2088 	 * __core_scsi3_write_aptpl_to_file() will call strlen()
2089 	 * on the passed buf to determine pr_aptpl_buf_len.
2090 	 */
2091 	ret = __core_scsi3_write_aptpl_to_file(dev, buf, 0);
2092 	if (ret != 0)
2093 		return ret;
2094 
2095 	return ret;
2096 }
2097 
2098 static int core_scsi3_emulate_pro_register(
2099 	struct se_cmd *cmd,
2100 	u64 res_key,
2101 	u64 sa_res_key,
2102 	int aptpl,
2103 	int all_tg_pt,
2104 	int spec_i_pt,
2105 	int ignore_key)
2106 {
2107 	struct se_session *se_sess = cmd->se_sess;
2108 	struct se_device *dev = cmd->se_dev;
2109 	struct se_dev_entry *se_deve;
2110 	struct se_lun *se_lun = cmd->se_lun;
2111 	struct se_portal_group *se_tpg;
2112 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_reg_tmp, *pr_reg_e;
2113 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2114 	/* Used for APTPL metadata w/ UNREGISTER */
2115 	unsigned char *pr_aptpl_buf = NULL;
2116 	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;
2117 	int pr_holder = 0, ret = 0, type;
2118 
2119 	if (!se_sess || !se_lun) {
2120 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2121 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2122 		return -EINVAL;
2123 	}
2124 	se_tpg = se_sess->se_tpg;
2125 	se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun];
2126 
2127 	if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) {
2128 		memset(&isid_buf[0], 0, PR_REG_ISID_LEN);
2129 		se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess, &isid_buf[0],
2130 				PR_REG_ISID_LEN);
2131 		isid_ptr = &isid_buf[0];
2132 	}
2133 	/*
2134 	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
2135 	 */
2136 	pr_reg_e = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2137 	if (!pr_reg_e) {
2138 		if (res_key) {
2139 			pr_warn("SPC-3 PR: Reservation Key non-zero"
2140 				" for SA REGISTER, returning CONFLICT\n");
2141 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2142 			return -EINVAL;
2143 		}
2144 		/*
2145 		 * Do nothing but return GOOD status.
2146 		 */
2147 		if (!sa_res_key)
2148 			return 0;
2149 
2150 		if (!spec_i_pt) {
2151 			/*
2152 			 * Perform the Service Action REGISTER on the Initiator
2153 			 * Port Endpoint that the PRO was received from on the
2154 			 * Logical Unit of the SCSI device server.
2155 			 */
2156 			ret = core_scsi3_alloc_registration(cmd->se_dev,
2157 					se_sess->se_node_acl, se_deve, isid_ptr,
2158 					sa_res_key, all_tg_pt, aptpl,
2159 					ignore_key, 0);
2160 			if (ret != 0) {
2161 				pr_err("Unable to allocate"
2162 					" struct t10_pr_registration\n");
2163 				cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
2164 				return -EINVAL;
2165 			}
2166 		} else {
2167 			/*
2168 			 * Register both the Initiator port that received
2169 			 * PROUT SA REGISTER + SPEC_I_PT=1 and extract SCSI
2170 			 * TransportID from Parameter list and loop through
2171 			 * fabric dependent parameter list while calling
2172 			 * logic from of core_scsi3_alloc_registration() for
2173 			 * each TransportID provided SCSI Initiator Port/Device
2174 			 */
2175 			ret = core_scsi3_decode_spec_i_port(cmd, se_tpg,
2176 					isid_ptr, sa_res_key, all_tg_pt, aptpl);
2177 			if (ret != 0)
2178 				return ret;
2179 		}
2180 		/*
2181 		 * Nothing left to do for the APTPL=0 case.
2182 		 */
2183 		if (!aptpl) {
2184 			pr_tmpl->pr_aptpl_active = 0;
2185 			core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2186 			pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
2187 					" REGISTER\n");
2188 			return 0;
2189 		}
2190 		/*
2191 		 * Locate the newly allocated local I_T Nexus *pr_reg, and
2192 		 * update the APTPL metadata information using its
2193 		 * preallocated *pr_reg->pr_aptpl_buf.
2194 		 */
2195 		pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev,
2196 				se_sess->se_node_acl, se_sess);
2197 
2198 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2199 				&pr_reg->pr_aptpl_buf[0],
2200 				pr_tmpl->pr_aptpl_buf_len);
2201 		if (!ret) {
2202 			pr_tmpl->pr_aptpl_active = 1;
2203 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for REGISTER\n");
2204 		}
2205 
2206 		core_scsi3_put_pr_reg(pr_reg);
2207 		return ret;
2208 	} else {
2209 		/*
2210 		 * Locate the existing *pr_reg via struct se_node_acl pointers
2211 		 */
2212 		pr_reg = pr_reg_e;
2213 		type = pr_reg->pr_res_type;
2214 
2215 		if (!ignore_key) {
2216 			if (res_key != pr_reg->pr_res_key) {
2217 				pr_err("SPC-3 PR REGISTER: Received"
2218 					" res_key: 0x%016Lx does not match"
2219 					" existing SA REGISTER res_key:"
2220 					" 0x%016Lx\n", res_key,
2221 					pr_reg->pr_res_key);
2222 				core_scsi3_put_pr_reg(pr_reg);
2223 				cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2224 				return -EINVAL;
2225 			}
2226 		}
2227 		if (spec_i_pt) {
2228 			pr_err("SPC-3 PR UNREGISTER: SPEC_I_PT"
2229 				" set while sa_res_key=0\n");
2230 			core_scsi3_put_pr_reg(pr_reg);
2231 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
2232 			return -EINVAL;
2233 		}
2234 		/*
2235 		 * An existing ALL_TG_PT=1 registration being released
2236 		 * must also set ALL_TG_PT=1 in the incoming PROUT.
2237 		 */
2238 		if (pr_reg->pr_reg_all_tg_pt && !(all_tg_pt)) {
2239 			pr_err("SPC-3 PR UNREGISTER: ALL_TG_PT=1"
2240 				" registration exists, but ALL_TG_PT=1 bit not"
2241 				" present in received PROUT\n");
2242 			core_scsi3_put_pr_reg(pr_reg);
2243 			cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2244 			return -EINVAL;
2245 		}
2246 		/*
2247 		 * Allocate APTPL metadata buffer used for UNREGISTER ops
2248 		 */
2249 		if (aptpl) {
2250 			pr_aptpl_buf = kzalloc(pr_tmpl->pr_aptpl_buf_len,
2251 						GFP_KERNEL);
2252 			if (!pr_aptpl_buf) {
2253 				pr_err("Unable to allocate"
2254 					" pr_aptpl_buf\n");
2255 				core_scsi3_put_pr_reg(pr_reg);
2256 				cmd->scsi_sense_reason =
2257 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2258 				return -EINVAL;
2259 			}
2260 		}
2261 		/*
2262 		 * sa_res_key=0 Unregister Reservation Key for registered I_T
2263 		 * Nexus sa_res_key=1 Change Reservation Key for registered I_T
2264 		 * Nexus.
2265 		 */
2266 		if (!sa_res_key) {
2267 			pr_holder = core_scsi3_check_implict_release(
2268 					cmd->se_dev, pr_reg);
2269 			if (pr_holder < 0) {
2270 				kfree(pr_aptpl_buf);
2271 				core_scsi3_put_pr_reg(pr_reg);
2272 				cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2273 				return -EINVAL;
2274 			}
2275 
2276 			spin_lock(&pr_tmpl->registration_lock);
2277 			/*
2278 			 * Release all ALL_TG_PT=1 for the matching SCSI Initiator Port
2279 			 * and matching pr_res_key.
2280 			 */
2281 			if (pr_reg->pr_reg_all_tg_pt) {
2282 				list_for_each_entry_safe(pr_reg_p, pr_reg_tmp,
2283 						&pr_tmpl->registration_list,
2284 						pr_reg_list) {
2285 
2286 					if (!pr_reg_p->pr_reg_all_tg_pt)
2287 						continue;
2288 
2289 					if (pr_reg_p->pr_res_key != res_key)
2290 						continue;
2291 
2292 					if (pr_reg == pr_reg_p)
2293 						continue;
2294 
2295 					if (strcmp(pr_reg->pr_reg_nacl->initiatorname,
2296 						   pr_reg_p->pr_reg_nacl->initiatorname))
2297 						continue;
2298 
2299 					__core_scsi3_free_registration(dev,
2300 							pr_reg_p, NULL, 0);
2301 				}
2302 			}
2303 			/*
2304 			 * Release the calling I_T Nexus registration now..
2305 			 */
2306 			__core_scsi3_free_registration(cmd->se_dev, pr_reg,
2307 							NULL, 1);
2308 			/*
2309 			 * From spc4r17, section 5.7.11.3 Unregistering
2310 			 *
2311 			 * If the persistent reservation is a registrants only
2312 			 * type, the device server shall establish a unit
2313 			 * attention condition for the initiator port associated
2314 			 * with every registered I_T nexus except for the I_T
2315 			 * nexus on which the PERSISTENT RESERVE OUT command was
2316 			 * received, with the additional sense code set to
2317 			 * RESERVATIONS RELEASED.
2318 			 */
2319 			if (pr_holder &&
2320 			   ((type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
2321 			    (type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY))) {
2322 				list_for_each_entry(pr_reg_p,
2323 						&pr_tmpl->registration_list,
2324 						pr_reg_list) {
2325 
2326 					core_scsi3_ua_allocate(
2327 						pr_reg_p->pr_reg_nacl,
2328 						pr_reg_p->pr_res_mapped_lun,
2329 						0x2A,
2330 						ASCQ_2AH_RESERVATIONS_RELEASED);
2331 				}
2332 			}
2333 			spin_unlock(&pr_tmpl->registration_lock);
2334 
2335 			if (!aptpl) {
2336 				pr_tmpl->pr_aptpl_active = 0;
2337 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2338 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2339 						" for UNREGISTER\n");
2340 				return 0;
2341 			}
2342 
2343 			ret = core_scsi3_update_and_write_aptpl(dev,
2344 					&pr_aptpl_buf[0],
2345 					pr_tmpl->pr_aptpl_buf_len);
2346 			if (!ret) {
2347 				pr_tmpl->pr_aptpl_active = 1;
2348 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2349 						" for UNREGISTER\n");
2350 			}
2351 
2352 			kfree(pr_aptpl_buf);
2353 			return ret;
2354 		} else {
2355 			/*
2356 			 * Increment PRgeneration counter for struct se_device"
2357 			 * upon a successful REGISTER, see spc4r17 section 6.3.2
2358 			 * READ_KEYS service action.
2359 			 */
2360 			pr_reg->pr_res_generation = core_scsi3_pr_generation(
2361 							cmd->se_dev);
2362 			pr_reg->pr_res_key = sa_res_key;
2363 			pr_debug("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
2364 				" Key for %s to: 0x%016Lx PRgeneration:"
2365 				" 0x%08x\n", cmd->se_tfo->get_fabric_name(),
2366 				(ignore_key) ? "_AND_IGNORE_EXISTING_KEY" : "",
2367 				pr_reg->pr_reg_nacl->initiatorname,
2368 				pr_reg->pr_res_key, pr_reg->pr_res_generation);
2369 
2370 			if (!aptpl) {
2371 				pr_tmpl->pr_aptpl_active = 0;
2372 				core_scsi3_update_and_write_aptpl(dev, NULL, 0);
2373 				core_scsi3_put_pr_reg(pr_reg);
2374 				pr_debug("SPC-3 PR: Set APTPL Bit Deactivated"
2375 						" for REGISTER\n");
2376 				return 0;
2377 			}
2378 
2379 			ret = core_scsi3_update_and_write_aptpl(dev,
2380 					&pr_aptpl_buf[0],
2381 					pr_tmpl->pr_aptpl_buf_len);
2382 			if (!ret) {
2383 				pr_tmpl->pr_aptpl_active = 1;
2384 				pr_debug("SPC-3 PR: Set APTPL Bit Activated"
2385 						" for REGISTER\n");
2386 			}
2387 
2388 			kfree(pr_aptpl_buf);
2389 			core_scsi3_put_pr_reg(pr_reg);
2390 		}
2391 	}
2392 	return 0;
2393 }
2394 
2395 unsigned char *core_scsi3_pr_dump_type(int type)
2396 {
2397 	switch (type) {
2398 	case PR_TYPE_WRITE_EXCLUSIVE:
2399 		return "Write Exclusive Access";
2400 	case PR_TYPE_EXCLUSIVE_ACCESS:
2401 		return "Exclusive Access";
2402 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2403 		return "Write Exclusive Access, Registrants Only";
2404 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2405 		return "Exclusive Access, Registrants Only";
2406 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2407 		return "Write Exclusive Access, All Registrants";
2408 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2409 		return "Exclusive Access, All Registrants";
2410 	default:
2411 		break;
2412 	}
2413 
2414 	return "Unknown SPC-3 PR Type";
2415 }
2416 
2417 static int core_scsi3_pro_reserve(
2418 	struct se_cmd *cmd,
2419 	struct se_device *dev,
2420 	int type,
2421 	int scope,
2422 	u64 res_key)
2423 {
2424 	struct se_session *se_sess = cmd->se_sess;
2425 	struct se_lun *se_lun = cmd->se_lun;
2426 	struct t10_pr_registration *pr_reg, *pr_res_holder;
2427 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2428 	char i_buf[PR_REG_ISID_ID_LEN];
2429 	int ret, prf_isid;
2430 
2431 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2432 
2433 	if (!se_sess || !se_lun) {
2434 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2435 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2436 		return -EINVAL;
2437 	}
2438 	/*
2439 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2440 	 */
2441 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
2442 				se_sess);
2443 	if (!pr_reg) {
2444 		pr_err("SPC-3 PR: Unable to locate"
2445 			" PR_REGISTERED *pr_reg for RESERVE\n");
2446 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2447 		return -EINVAL;
2448 	}
2449 	/*
2450 	 * From spc4r17 Section 5.7.9: Reserving:
2451 	 *
2452 	 * An application client creates a persistent reservation by issuing
2453 	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
2454 	 * a registered I_T nexus with the following parameters:
2455 	 *    a) RESERVATION KEY set to the value of the reservation key that is
2456 	 * 	 registered with the logical unit for the I_T nexus; and
2457 	 */
2458 	if (res_key != pr_reg->pr_res_key) {
2459 		pr_err("SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
2460 			" does not match existing SA REGISTER res_key:"
2461 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2462 		core_scsi3_put_pr_reg(pr_reg);
2463 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2464 		return -EINVAL;
2465 	}
2466 	/*
2467 	 * From spc4r17 Section 5.7.9: Reserving:
2468 	 *
2469 	 * From above:
2470 	 *  b) TYPE field and SCOPE field set to the persistent reservation
2471 	 *     being created.
2472 	 *
2473 	 * Only one persistent reservation is allowed at a time per logical unit
2474 	 * and that persistent reservation has a scope of LU_SCOPE.
2475 	 */
2476 	if (scope != PR_SCOPE_LU_SCOPE) {
2477 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
2478 		core_scsi3_put_pr_reg(pr_reg);
2479 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
2480 		return -EINVAL;
2481 	}
2482 	/*
2483 	 * See if we have an existing PR reservation holder pointer at
2484 	 * struct se_device->dev_pr_res_holder in the form struct t10_pr_registration
2485 	 * *pr_res_holder.
2486 	 */
2487 	spin_lock(&dev->dev_reservation_lock);
2488 	pr_res_holder = dev->dev_pr_res_holder;
2489 	if (pr_res_holder) {
2490 		/*
2491 		 * From spc4r17 Section 5.7.9: Reserving:
2492 		 *
2493 		 * If the device server receives a PERSISTENT RESERVE OUT
2494 		 * command from an I_T nexus other than a persistent reservation
2495 		 * holder (see 5.7.10) that attempts to create a persistent
2496 		 * reservation when a persistent reservation already exists for
2497 		 * the logical unit, then the command shall be completed with
2498 		 * RESERVATION CONFLICT status.
2499 		 */
2500 		if (pr_res_holder != pr_reg) {
2501 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2502 			pr_err("SPC-3 PR: Attempted RESERVE from"
2503 				" [%s]: %s while reservation already held by"
2504 				" [%s]: %s, returning RESERVATION_CONFLICT\n",
2505 				cmd->se_tfo->get_fabric_name(),
2506 				se_sess->se_node_acl->initiatorname,
2507 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2508 				pr_res_holder->pr_reg_nacl->initiatorname);
2509 
2510 			spin_unlock(&dev->dev_reservation_lock);
2511 			core_scsi3_put_pr_reg(pr_reg);
2512 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2513 			return -EINVAL;
2514 		}
2515 		/*
2516 		 * From spc4r17 Section 5.7.9: Reserving:
2517 		 *
2518 		 * If a persistent reservation holder attempts to modify the
2519 		 * type or scope of an existing persistent reservation, the
2520 		 * command shall be completed with RESERVATION CONFLICT status.
2521 		 */
2522 		if ((pr_res_holder->pr_res_type != type) ||
2523 		    (pr_res_holder->pr_res_scope != scope)) {
2524 			struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2525 			pr_err("SPC-3 PR: Attempted RESERVE from"
2526 				" [%s]: %s trying to change TYPE and/or SCOPE,"
2527 				" while reservation already held by [%s]: %s,"
2528 				" returning RESERVATION_CONFLICT\n",
2529 				cmd->se_tfo->get_fabric_name(),
2530 				se_sess->se_node_acl->initiatorname,
2531 				pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2532 				pr_res_holder->pr_reg_nacl->initiatorname);
2533 
2534 			spin_unlock(&dev->dev_reservation_lock);
2535 			core_scsi3_put_pr_reg(pr_reg);
2536 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2537 			return -EINVAL;
2538 		}
2539 		/*
2540 		 * From spc4r17 Section 5.7.9: Reserving:
2541 		 *
2542 		 * If the device server receives a PERSISTENT RESERVE OUT
2543 		 * command with RESERVE service action where the TYPE field and
2544 		 * the SCOPE field contain the same values as the existing type
2545 		 * and scope from a persistent reservation holder, it shall not
2546 		 * make any change to the existing persistent reservation and
2547 		 * shall completethe command with GOOD status.
2548 		 */
2549 		spin_unlock(&dev->dev_reservation_lock);
2550 		core_scsi3_put_pr_reg(pr_reg);
2551 		return 0;
2552 	}
2553 	/*
2554 	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
2555 	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
2556 	 */
2557 	pr_reg->pr_res_scope = scope;
2558 	pr_reg->pr_res_type = type;
2559 	pr_reg->pr_res_holder = 1;
2560 	dev->dev_pr_res_holder = pr_reg;
2561 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2562 				PR_REG_ISID_ID_LEN);
2563 
2564 	pr_debug("SPC-3 PR [%s] Service Action: RESERVE created new"
2565 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2566 		cmd->se_tfo->get_fabric_name(), core_scsi3_pr_dump_type(type),
2567 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2568 	pr_debug("SPC-3 PR [%s] RESERVE Node: %s%s\n",
2569 			cmd->se_tfo->get_fabric_name(),
2570 			se_sess->se_node_acl->initiatorname,
2571 			(prf_isid) ? &i_buf[0] : "");
2572 	spin_unlock(&dev->dev_reservation_lock);
2573 
2574 	if (pr_tmpl->pr_aptpl_active) {
2575 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2576 				&pr_reg->pr_aptpl_buf[0],
2577 				pr_tmpl->pr_aptpl_buf_len);
2578 		if (!ret)
2579 			pr_debug("SPC-3 PR: Updated APTPL metadata"
2580 					" for RESERVE\n");
2581 	}
2582 
2583 	core_scsi3_put_pr_reg(pr_reg);
2584 	return 0;
2585 }
2586 
2587 static int core_scsi3_emulate_pro_reserve(
2588 	struct se_cmd *cmd,
2589 	int type,
2590 	int scope,
2591 	u64 res_key)
2592 {
2593 	struct se_device *dev = cmd->se_dev;
2594 	int ret = 0;
2595 
2596 	switch (type) {
2597 	case PR_TYPE_WRITE_EXCLUSIVE:
2598 	case PR_TYPE_EXCLUSIVE_ACCESS:
2599 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
2600 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
2601 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
2602 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
2603 		ret = core_scsi3_pro_reserve(cmd, dev, type, scope, res_key);
2604 		break;
2605 	default:
2606 		pr_err("SPC-3 PR: Unknown Service Action RESERVE Type:"
2607 			" 0x%02x\n", type);
2608 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2609 		return -EINVAL;
2610 	}
2611 
2612 	return ret;
2613 }
2614 
2615 /*
2616  * Called with struct se_device->dev_reservation_lock held.
2617  */
2618 static void __core_scsi3_complete_pro_release(
2619 	struct se_device *dev,
2620 	struct se_node_acl *se_nacl,
2621 	struct t10_pr_registration *pr_reg,
2622 	int explict)
2623 {
2624 	struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
2625 	char i_buf[PR_REG_ISID_ID_LEN];
2626 	int prf_isid;
2627 
2628 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2629 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2630 				PR_REG_ISID_ID_LEN);
2631 	/*
2632 	 * Go ahead and release the current PR reservation holder.
2633 	 */
2634 	dev->dev_pr_res_holder = NULL;
2635 
2636 	pr_debug("SPC-3 PR [%s] Service Action: %s RELEASE cleared"
2637 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2638 		tfo->get_fabric_name(), (explict) ? "explict" : "implict",
2639 		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
2640 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2641 	pr_debug("SPC-3 PR [%s] RELEASE Node: %s%s\n",
2642 		tfo->get_fabric_name(), se_nacl->initiatorname,
2643 		(prf_isid) ? &i_buf[0] : "");
2644 	/*
2645 	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
2646 	 */
2647 	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
2648 }
2649 
2650 static int core_scsi3_emulate_pro_release(
2651 	struct se_cmd *cmd,
2652 	int type,
2653 	int scope,
2654 	u64 res_key)
2655 {
2656 	struct se_device *dev = cmd->se_dev;
2657 	struct se_session *se_sess = cmd->se_sess;
2658 	struct se_lun *se_lun = cmd->se_lun;
2659 	struct t10_pr_registration *pr_reg, *pr_reg_p, *pr_res_holder;
2660 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2661 	int ret, all_reg = 0;
2662 
2663 	if (!se_sess || !se_lun) {
2664 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
2665 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2666 		return -EINVAL;
2667 	}
2668 	/*
2669 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2670 	 */
2671 	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl, se_sess);
2672 	if (!pr_reg) {
2673 		pr_err("SPC-3 PR: Unable to locate"
2674 			" PR_REGISTERED *pr_reg for RELEASE\n");
2675 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2676 		return -EINVAL;
2677 	}
2678 	/*
2679 	 * From spc4r17 Section 5.7.11.2 Releasing:
2680 	 *
2681 	 * If there is no persistent reservation or in response to a persistent
2682 	 * reservation release request from a registered I_T nexus that is not a
2683 	 * persistent reservation holder (see 5.7.10), the device server shall
2684 	 * do the following:
2685 	 *
2686 	 *     a) Not release the persistent reservation, if any;
2687 	 *     b) Not remove any registrations; and
2688 	 *     c) Complete the command with GOOD status.
2689 	 */
2690 	spin_lock(&dev->dev_reservation_lock);
2691 	pr_res_holder = dev->dev_pr_res_holder;
2692 	if (!pr_res_holder) {
2693 		/*
2694 		 * No persistent reservation, return GOOD status.
2695 		 */
2696 		spin_unlock(&dev->dev_reservation_lock);
2697 		core_scsi3_put_pr_reg(pr_reg);
2698 		return 0;
2699 	}
2700 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
2701 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
2702 		all_reg = 1;
2703 
2704 	if ((all_reg == 0) && (pr_res_holder != pr_reg)) {
2705 		/*
2706 		 * Non 'All Registrants' PR Type cases..
2707 		 * Release request from a registered I_T nexus that is not a
2708 		 * persistent reservation holder. return GOOD status.
2709 		 */
2710 		spin_unlock(&dev->dev_reservation_lock);
2711 		core_scsi3_put_pr_reg(pr_reg);
2712 		return 0;
2713 	}
2714 	/*
2715 	 * From spc4r17 Section 5.7.11.2 Releasing:
2716 	 *
2717 	 * Only the persistent reservation holder (see 5.7.10) is allowed to
2718 	 * release a persistent reservation.
2719 	 *
2720 	 * An application client releases the persistent reservation by issuing
2721 	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
2722 	 * an I_T nexus that is a persistent reservation holder with the
2723 	 * following parameters:
2724 	 *
2725 	 *     a) RESERVATION KEY field set to the value of the reservation key
2726 	 *	  that is registered with the logical unit for the I_T nexus;
2727 	 */
2728 	if (res_key != pr_reg->pr_res_key) {
2729 		pr_err("SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
2730 			" does not match existing SA REGISTER res_key:"
2731 			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
2732 		spin_unlock(&dev->dev_reservation_lock);
2733 		core_scsi3_put_pr_reg(pr_reg);
2734 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2735 		return -EINVAL;
2736 	}
2737 	/*
2738 	 * From spc4r17 Section 5.7.11.2 Releasing and above:
2739 	 *
2740 	 * b) TYPE field and SCOPE field set to match the persistent
2741 	 *    reservation being released.
2742 	 */
2743 	if ((pr_res_holder->pr_res_type != type) ||
2744 	    (pr_res_holder->pr_res_scope != scope)) {
2745 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2746 		pr_err("SPC-3 PR RELEASE: Attempted to release"
2747 			" reservation from [%s]: %s with different TYPE "
2748 			"and/or SCOPE  while reservation already held by"
2749 			" [%s]: %s, returning RESERVATION_CONFLICT\n",
2750 			cmd->se_tfo->get_fabric_name(),
2751 			se_sess->se_node_acl->initiatorname,
2752 			pr_res_nacl->se_tpg->se_tpg_tfo->get_fabric_name(),
2753 			pr_res_holder->pr_reg_nacl->initiatorname);
2754 
2755 		spin_unlock(&dev->dev_reservation_lock);
2756 		core_scsi3_put_pr_reg(pr_reg);
2757 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2758 		return -EINVAL;
2759 	}
2760 	/*
2761 	 * In response to a persistent reservation release request from the
2762 	 * persistent reservation holder the device server shall perform a
2763 	 * release by doing the following as an uninterrupted series of actions:
2764 	 * a) Release the persistent reservation;
2765 	 * b) Not remove any registration(s);
2766 	 * c) If the released persistent reservation is a registrants only type
2767 	 * or all registrants type persistent reservation,
2768 	 *    the device server shall establish a unit attention condition for
2769 	 *    the initiator port associated with every regis-
2770 	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
2771 	 *    RESERVE OUT command with RELEASE service action was received,
2772 	 *    with the additional sense code set to RESERVATIONS RELEASED; and
2773 	 * d) If the persistent reservation is of any other type, the device
2774 	 *    server shall not establish a unit attention condition.
2775 	 */
2776 	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
2777 			pr_reg, 1);
2778 
2779 	spin_unlock(&dev->dev_reservation_lock);
2780 
2781 	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
2782 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
2783 	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
2784 	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
2785 		/*
2786 		 * If no UNIT ATTENTION conditions will be established for
2787 		 * PR_TYPE_WRITE_EXCLUSIVE or PR_TYPE_EXCLUSIVE_ACCESS
2788 		 * go ahead and check for APTPL=1 update+write below
2789 		 */
2790 		goto write_aptpl;
2791 	}
2792 
2793 	spin_lock(&pr_tmpl->registration_lock);
2794 	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
2795 			pr_reg_list) {
2796 		/*
2797 		 * Do not establish a UNIT ATTENTION condition
2798 		 * for the calling I_T Nexus
2799 		 */
2800 		if (pr_reg_p == pr_reg)
2801 			continue;
2802 
2803 		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
2804 				pr_reg_p->pr_res_mapped_lun,
2805 				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
2806 	}
2807 	spin_unlock(&pr_tmpl->registration_lock);
2808 
2809 write_aptpl:
2810 	if (pr_tmpl->pr_aptpl_active) {
2811 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
2812 				&pr_reg->pr_aptpl_buf[0],
2813 				pr_tmpl->pr_aptpl_buf_len);
2814 		if (!ret)
2815 			pr_debug("SPC-3 PR: Updated APTPL metadata for RELEASE\n");
2816 	}
2817 
2818 	core_scsi3_put_pr_reg(pr_reg);
2819 	return 0;
2820 }
2821 
2822 static int core_scsi3_emulate_pro_clear(
2823 	struct se_cmd *cmd,
2824 	u64 res_key)
2825 {
2826 	struct se_device *dev = cmd->se_dev;
2827 	struct se_node_acl *pr_reg_nacl;
2828 	struct se_session *se_sess = cmd->se_sess;
2829 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
2830 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2831 	u32 pr_res_mapped_lun = 0;
2832 	int calling_it_nexus = 0;
2833 	/*
2834 	 * Locate the existing *pr_reg via struct se_node_acl pointers
2835 	 */
2836 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev,
2837 			se_sess->se_node_acl, se_sess);
2838 	if (!pr_reg_n) {
2839 		pr_err("SPC-3 PR: Unable to locate"
2840 			" PR_REGISTERED *pr_reg for CLEAR\n");
2841 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2842 		return -EINVAL;
2843 	}
2844 	/*
2845 	 * From spc4r17 section 5.7.11.6, Clearing:
2846 	 *
2847 	 * Any application client may release the persistent reservation and
2848 	 * remove all registrations from a device server by issuing a
2849 	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
2850 	 * registered I_T nexus with the following parameter:
2851 	 *
2852 	 *	a) RESERVATION KEY field set to the value of the reservation key
2853 	 * 	   that is registered with the logical unit for the I_T nexus.
2854 	 */
2855 	if (res_key != pr_reg_n->pr_res_key) {
2856 		pr_err("SPC-3 PR REGISTER: Received"
2857 			" res_key: 0x%016Lx does not match"
2858 			" existing SA REGISTER res_key:"
2859 			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
2860 		core_scsi3_put_pr_reg(pr_reg_n);
2861 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
2862 		return -EINVAL;
2863 	}
2864 	/*
2865 	 * a) Release the persistent reservation, if any;
2866 	 */
2867 	spin_lock(&dev->dev_reservation_lock);
2868 	pr_res_holder = dev->dev_pr_res_holder;
2869 	if (pr_res_holder) {
2870 		struct se_node_acl *pr_res_nacl = pr_res_holder->pr_reg_nacl;
2871 		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
2872 			pr_res_holder, 0);
2873 	}
2874 	spin_unlock(&dev->dev_reservation_lock);
2875 	/*
2876 	 * b) Remove all registration(s) (see spc4r17 5.7.7);
2877 	 */
2878 	spin_lock(&pr_tmpl->registration_lock);
2879 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
2880 			&pr_tmpl->registration_list, pr_reg_list) {
2881 
2882 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
2883 		pr_reg_nacl = pr_reg->pr_reg_nacl;
2884 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
2885 		__core_scsi3_free_registration(dev, pr_reg, NULL,
2886 					calling_it_nexus);
2887 		/*
2888 		 * e) Establish a unit attention condition for the initiator
2889 		 *    port associated with every registered I_T nexus other
2890 		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
2891 		 *    command with CLEAR service action was received, with the
2892 		 *    additional sense code set to RESERVATIONS PREEMPTED.
2893 		 */
2894 		if (!calling_it_nexus)
2895 			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
2896 				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
2897 	}
2898 	spin_unlock(&pr_tmpl->registration_lock);
2899 
2900 	pr_debug("SPC-3 PR [%s] Service Action: CLEAR complete\n",
2901 		cmd->se_tfo->get_fabric_name());
2902 
2903 	if (pr_tmpl->pr_aptpl_active) {
2904 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
2905 		pr_debug("SPC-3 PR: Updated APTPL metadata"
2906 				" for CLEAR\n");
2907 	}
2908 
2909 	core_scsi3_pr_generation(dev);
2910 	return 0;
2911 }
2912 
2913 /*
2914  * Called with struct se_device->dev_reservation_lock held.
2915  */
2916 static void __core_scsi3_complete_pro_preempt(
2917 	struct se_device *dev,
2918 	struct t10_pr_registration *pr_reg,
2919 	struct list_head *preempt_and_abort_list,
2920 	int type,
2921 	int scope,
2922 	int abort)
2923 {
2924 	struct se_node_acl *nacl = pr_reg->pr_reg_nacl;
2925 	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
2926 	char i_buf[PR_REG_ISID_ID_LEN];
2927 	int prf_isid;
2928 
2929 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
2930 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
2931 				PR_REG_ISID_ID_LEN);
2932 	/*
2933 	 * Do an implict RELEASE of the existing reservation.
2934 	 */
2935 	if (dev->dev_pr_res_holder)
2936 		__core_scsi3_complete_pro_release(dev, nacl,
2937 				dev->dev_pr_res_holder, 0);
2938 
2939 	dev->dev_pr_res_holder = pr_reg;
2940 	pr_reg->pr_res_holder = 1;
2941 	pr_reg->pr_res_type = type;
2942 	pr_reg->pr_res_scope = scope;
2943 
2944 	pr_debug("SPC-3 PR [%s] Service Action: PREEMPT%s created new"
2945 		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
2946 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2947 		core_scsi3_pr_dump_type(type),
2948 		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
2949 	pr_debug("SPC-3 PR [%s] PREEMPT%s from Node: %s%s\n",
2950 		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
2951 		nacl->initiatorname, (prf_isid) ? &i_buf[0] : "");
2952 	/*
2953 	 * For PREEMPT_AND_ABORT, add the preempting reservation's
2954 	 * struct t10_pr_registration to the list that will be compared
2955 	 * against received CDBs..
2956 	 */
2957 	if (preempt_and_abort_list)
2958 		list_add_tail(&pr_reg->pr_reg_abort_list,
2959 				preempt_and_abort_list);
2960 }
2961 
2962 static void core_scsi3_release_preempt_and_abort(
2963 	struct list_head *preempt_and_abort_list,
2964 	struct t10_pr_registration *pr_reg_holder)
2965 {
2966 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
2967 
2968 	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
2969 				pr_reg_abort_list) {
2970 
2971 		list_del(&pr_reg->pr_reg_abort_list);
2972 		if (pr_reg_holder == pr_reg)
2973 			continue;
2974 		if (pr_reg->pr_res_holder) {
2975 			pr_warn("pr_reg->pr_res_holder still set\n");
2976 			continue;
2977 		}
2978 
2979 		pr_reg->pr_reg_deve = NULL;
2980 		pr_reg->pr_reg_nacl = NULL;
2981 		kfree(pr_reg->pr_aptpl_buf);
2982 		kmem_cache_free(t10_pr_reg_cache, pr_reg);
2983 	}
2984 }
2985 
2986 static int core_scsi3_pro_preempt(
2987 	struct se_cmd *cmd,
2988 	int type,
2989 	int scope,
2990 	u64 res_key,
2991 	u64 sa_res_key,
2992 	int abort)
2993 {
2994 	struct se_device *dev = cmd->se_dev;
2995 	struct se_node_acl *pr_reg_nacl;
2996 	struct se_session *se_sess = cmd->se_sess;
2997 	LIST_HEAD(preempt_and_abort_list);
2998 	struct t10_pr_registration *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
2999 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3000 	u32 pr_res_mapped_lun = 0;
3001 	int all_reg = 0, calling_it_nexus = 0, released_regs = 0;
3002 	int prh_type = 0, prh_scope = 0, ret;
3003 
3004 	if (!se_sess) {
3005 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3006 		return -EINVAL;
3007 	}
3008 
3009 	pr_reg_n = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3010 				se_sess);
3011 	if (!pr_reg_n) {
3012 		pr_err("SPC-3 PR: Unable to locate"
3013 			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
3014 			(abort) ? "_AND_ABORT" : "");
3015 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3016 		return -EINVAL;
3017 	}
3018 	if (pr_reg_n->pr_res_key != res_key) {
3019 		core_scsi3_put_pr_reg(pr_reg_n);
3020 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3021 		return -EINVAL;
3022 	}
3023 	if (scope != PR_SCOPE_LU_SCOPE) {
3024 		pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
3025 		core_scsi3_put_pr_reg(pr_reg_n);
3026 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3027 		return -EINVAL;
3028 	}
3029 
3030 	spin_lock(&dev->dev_reservation_lock);
3031 	pr_res_holder = dev->dev_pr_res_holder;
3032 	if (pr_res_holder &&
3033 	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3034 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
3035 		all_reg = 1;
3036 
3037 	if (!all_reg && !sa_res_key) {
3038 		spin_unlock(&dev->dev_reservation_lock);
3039 		core_scsi3_put_pr_reg(pr_reg_n);
3040 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3041 		return -EINVAL;
3042 	}
3043 	/*
3044 	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
3045 	 *
3046 	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
3047 	 * persistent reservation holder or there is no persistent reservation
3048 	 * holder (i.e., there is no persistent reservation), then the device
3049 	 * server shall perform a preempt by doing the following in an
3050 	 * uninterrupted series of actions. (See below..)
3051 	 */
3052 	if (!pr_res_holder || (pr_res_holder->pr_res_key != sa_res_key)) {
3053 		/*
3054 		 * No existing or SA Reservation Key matching reservations..
3055 		 *
3056 		 * PROUT SA PREEMPT with All Registrant type reservations are
3057 		 * allowed to be processed without a matching SA Reservation Key
3058 		 */
3059 		spin_lock(&pr_tmpl->registration_lock);
3060 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3061 				&pr_tmpl->registration_list, pr_reg_list) {
3062 			/*
3063 			 * Removing of registrations in non all registrants
3064 			 * type reservations without a matching SA reservation
3065 			 * key.
3066 			 *
3067 			 * a) Remove the registrations for all I_T nexuses
3068 			 *    specified by the SERVICE ACTION RESERVATION KEY
3069 			 *    field;
3070 			 * b) Ignore the contents of the SCOPE and TYPE fields;
3071 			 * c) Process tasks as defined in 5.7.1; and
3072 			 * d) Establish a unit attention condition for the
3073 			 *    initiator port associated with every I_T nexus
3074 			 *    that lost its registration other than the I_T
3075 			 *    nexus on which the PERSISTENT RESERVE OUT command
3076 			 *    was received, with the additional sense code set
3077 			 *    to REGISTRATIONS PREEMPTED.
3078 			 */
3079 			if (!all_reg) {
3080 				if (pr_reg->pr_res_key != sa_res_key)
3081 					continue;
3082 
3083 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3084 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3085 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3086 				__core_scsi3_free_registration(dev, pr_reg,
3087 					(abort) ? &preempt_and_abort_list :
3088 						NULL, calling_it_nexus);
3089 				released_regs++;
3090 			} else {
3091 				/*
3092 				 * Case for any existing all registrants type
3093 				 * reservation, follow logic in spc4r17 section
3094 				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
3095 				 *
3096 				 * For a ZERO SA Reservation key, release
3097 				 * all other registrations and do an implict
3098 				 * release of active persistent reservation.
3099 				 *
3100 				 * For a non-ZERO SA Reservation key, only
3101 				 * release the matching reservation key from
3102 				 * registrations.
3103 				 */
3104 				if ((sa_res_key) &&
3105 				     (pr_reg->pr_res_key != sa_res_key))
3106 					continue;
3107 
3108 				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3109 				if (calling_it_nexus)
3110 					continue;
3111 
3112 				pr_reg_nacl = pr_reg->pr_reg_nacl;
3113 				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3114 				__core_scsi3_free_registration(dev, pr_reg,
3115 					(abort) ? &preempt_and_abort_list :
3116 						NULL, 0);
3117 				released_regs++;
3118 			}
3119 			if (!calling_it_nexus)
3120 				core_scsi3_ua_allocate(pr_reg_nacl,
3121 					pr_res_mapped_lun, 0x2A,
3122 					ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3123 		}
3124 		spin_unlock(&pr_tmpl->registration_lock);
3125 		/*
3126 		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
3127 		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
3128 		 * RESERVATION KEY field to a value that does not match any
3129 		 * registered reservation key, then the device server shall
3130 		 * complete the command with RESERVATION CONFLICT status.
3131 		 */
3132 		if (!released_regs) {
3133 			spin_unlock(&dev->dev_reservation_lock);
3134 			core_scsi3_put_pr_reg(pr_reg_n);
3135 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3136 			return -EINVAL;
3137 		}
3138 		/*
3139 		 * For an existing all registrants type reservation
3140 		 * with a zero SA rservation key, preempt the existing
3141 		 * reservation with the new PR type and scope.
3142 		 */
3143 		if (pr_res_holder && all_reg && !(sa_res_key)) {
3144 			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3145 				(abort) ? &preempt_and_abort_list : NULL,
3146 				type, scope, abort);
3147 
3148 			if (abort)
3149 				core_scsi3_release_preempt_and_abort(
3150 					&preempt_and_abort_list, pr_reg_n);
3151 		}
3152 		spin_unlock(&dev->dev_reservation_lock);
3153 
3154 		if (pr_tmpl->pr_aptpl_active) {
3155 			ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3156 					&pr_reg_n->pr_aptpl_buf[0],
3157 					pr_tmpl->pr_aptpl_buf_len);
3158 			if (!ret)
3159 				pr_debug("SPC-3 PR: Updated APTPL"
3160 					" metadata for  PREEMPT%s\n", (abort) ?
3161 					"_AND_ABORT" : "");
3162 		}
3163 
3164 		core_scsi3_put_pr_reg(pr_reg_n);
3165 		core_scsi3_pr_generation(cmd->se_dev);
3166 		return 0;
3167 	}
3168 	/*
3169 	 * The PREEMPTing SA reservation key matches that of the
3170 	 * existing persistent reservation, first, we check if
3171 	 * we are preempting our own reservation.
3172 	 * From spc4r17, section 5.7.11.4.3 Preempting
3173 	 * persistent reservations and registration handling
3174 	 *
3175 	 * If an all registrants persistent reservation is not
3176 	 * present, it is not an error for the persistent
3177 	 * reservation holder to preempt itself (i.e., a
3178 	 * PERSISTENT RESERVE OUT with a PREEMPT service action
3179 	 * or a PREEMPT AND ABORT service action with the
3180 	 * SERVICE ACTION RESERVATION KEY value equal to the
3181 	 * persistent reservation holder's reservation key that
3182 	 * is received from the persistent reservation holder).
3183 	 * In that case, the device server shall establish the
3184 	 * new persistent reservation and maintain the
3185 	 * registration.
3186 	 */
3187 	prh_type = pr_res_holder->pr_res_type;
3188 	prh_scope = pr_res_holder->pr_res_scope;
3189 	/*
3190 	 * If the SERVICE ACTION RESERVATION KEY field identifies a
3191 	 * persistent reservation holder (see 5.7.10), the device
3192 	 * server shall perform a preempt by doing the following as
3193 	 * an uninterrupted series of actions:
3194 	 *
3195 	 * a) Release the persistent reservation for the holder
3196 	 *    identified by the SERVICE ACTION RESERVATION KEY field;
3197 	 */
3198 	if (pr_reg_n != pr_res_holder)
3199 		__core_scsi3_complete_pro_release(dev,
3200 				pr_res_holder->pr_reg_nacl,
3201 				dev->dev_pr_res_holder, 0);
3202 	/*
3203 	 * b) Remove the registrations for all I_T nexuses identified
3204 	 *    by the SERVICE ACTION RESERVATION KEY field, except the
3205 	 *    I_T nexus that is being used for the PERSISTENT RESERVE
3206 	 *    OUT command. If an all registrants persistent reservation
3207 	 *    is present and the SERVICE ACTION RESERVATION KEY field
3208 	 *    is set to zero, then all registrations shall be removed
3209 	 *    except for that of the I_T nexus that is being used for
3210 	 *    the PERSISTENT RESERVE OUT command;
3211 	 */
3212 	spin_lock(&pr_tmpl->registration_lock);
3213 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3214 			&pr_tmpl->registration_list, pr_reg_list) {
3215 
3216 		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3217 		if (calling_it_nexus)
3218 			continue;
3219 
3220 		if (pr_reg->pr_res_key != sa_res_key)
3221 			continue;
3222 
3223 		pr_reg_nacl = pr_reg->pr_reg_nacl;
3224 		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
3225 		__core_scsi3_free_registration(dev, pr_reg,
3226 				(abort) ? &preempt_and_abort_list : NULL,
3227 				calling_it_nexus);
3228 		/*
3229 		 * e) Establish a unit attention condition for the initiator
3230 		 *    port associated with every I_T nexus that lost its
3231 		 *    persistent reservation and/or registration, with the
3232 		 *    additional sense code set to REGISTRATIONS PREEMPTED;
3233 		 */
3234 		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
3235 				ASCQ_2AH_REGISTRATIONS_PREEMPTED);
3236 	}
3237 	spin_unlock(&pr_tmpl->registration_lock);
3238 	/*
3239 	 * c) Establish a persistent reservation for the preempting
3240 	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
3241 	 */
3242 	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
3243 			(abort) ? &preempt_and_abort_list : NULL,
3244 			type, scope, abort);
3245 	/*
3246 	 * d) Process tasks as defined in 5.7.1;
3247 	 * e) See above..
3248 	 * f) If the type or scope has changed, then for every I_T nexus
3249 	 *    whose reservation key was not removed, except for the I_T
3250 	 *    nexus on which the PERSISTENT RESERVE OUT command was
3251 	 *    received, the device server shall establish a unit
3252 	 *    attention condition for the initiator port associated with
3253 	 *    that I_T nexus, with the additional sense code set to
3254 	 *    RESERVATIONS RELEASED. If the type or scope have not
3255 	 *    changed, then no unit attention condition(s) shall be
3256 	 *    established for this reason.
3257 	 */
3258 	if ((prh_type != type) || (prh_scope != scope)) {
3259 		spin_lock(&pr_tmpl->registration_lock);
3260 		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
3261 				&pr_tmpl->registration_list, pr_reg_list) {
3262 
3263 			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
3264 			if (calling_it_nexus)
3265 				continue;
3266 
3267 			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
3268 					pr_reg->pr_res_mapped_lun, 0x2A,
3269 					ASCQ_2AH_RESERVATIONS_RELEASED);
3270 		}
3271 		spin_unlock(&pr_tmpl->registration_lock);
3272 	}
3273 	spin_unlock(&dev->dev_reservation_lock);
3274 	/*
3275 	 * Call LUN_RESET logic upon list of struct t10_pr_registration,
3276 	 * All received CDBs for the matching existing reservation and
3277 	 * registrations undergo ABORT_TASK logic.
3278 	 *
3279 	 * From there, core_scsi3_release_preempt_and_abort() will
3280 	 * release every registration in the list (which have already
3281 	 * been removed from the primary pr_reg list), except the
3282 	 * new persistent reservation holder, the calling Initiator Port.
3283 	 */
3284 	if (abort) {
3285 		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
3286 		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
3287 						pr_reg_n);
3288 	}
3289 
3290 	if (pr_tmpl->pr_aptpl_active) {
3291 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3292 				&pr_reg_n->pr_aptpl_buf[0],
3293 				pr_tmpl->pr_aptpl_buf_len);
3294 		if (!ret)
3295 			pr_debug("SPC-3 PR: Updated APTPL metadata for PREEMPT"
3296 				"%s\n", (abort) ? "_AND_ABORT" : "");
3297 	}
3298 
3299 	core_scsi3_put_pr_reg(pr_reg_n);
3300 	core_scsi3_pr_generation(cmd->se_dev);
3301 	return 0;
3302 }
3303 
3304 static int core_scsi3_emulate_pro_preempt(
3305 	struct se_cmd *cmd,
3306 	int type,
3307 	int scope,
3308 	u64 res_key,
3309 	u64 sa_res_key,
3310 	int abort)
3311 {
3312 	int ret = 0;
3313 
3314 	switch (type) {
3315 	case PR_TYPE_WRITE_EXCLUSIVE:
3316 	case PR_TYPE_EXCLUSIVE_ACCESS:
3317 	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
3318 	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
3319 	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
3320 	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
3321 		ret = core_scsi3_pro_preempt(cmd, type, scope,
3322 				res_key, sa_res_key, abort);
3323 		break;
3324 	default:
3325 		pr_err("SPC-3 PR: Unknown Service Action PREEMPT%s"
3326 			" Type: 0x%02x\n", (abort) ? "_AND_ABORT" : "", type);
3327 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3328 		return -EINVAL;
3329 	}
3330 
3331 	return ret;
3332 }
3333 
3334 
3335 static int core_scsi3_emulate_pro_register_and_move(
3336 	struct se_cmd *cmd,
3337 	u64 res_key,
3338 	u64 sa_res_key,
3339 	int aptpl,
3340 	int unreg)
3341 {
3342 	struct se_session *se_sess = cmd->se_sess;
3343 	struct se_device *dev = cmd->se_dev;
3344 	struct se_dev_entry *dest_se_deve = NULL;
3345 	struct se_lun *se_lun = cmd->se_lun;
3346 	struct se_node_acl *pr_res_nacl, *pr_reg_nacl, *dest_node_acl = NULL;
3347 	struct se_port *se_port;
3348 	struct se_portal_group *se_tpg, *dest_se_tpg = NULL;
3349 	struct target_core_fabric_ops *dest_tf_ops = NULL, *tf_ops;
3350 	struct t10_pr_registration *pr_reg, *pr_res_holder, *dest_pr_reg;
3351 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
3352 	unsigned char *buf;
3353 	unsigned char *initiator_str;
3354 	char *iport_ptr = NULL, dest_iport[64], i_buf[PR_REG_ISID_ID_LEN];
3355 	u32 tid_len, tmp_tid_len;
3356 	int new_reg = 0, type, scope, ret, matching_iname, prf_isid;
3357 	unsigned short rtpi;
3358 	unsigned char proto_ident;
3359 
3360 	if (!se_sess || !se_lun) {
3361 		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
3362 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3363 		return -EINVAL;
3364 	}
3365 	memset(dest_iport, 0, 64);
3366 	memset(i_buf, 0, PR_REG_ISID_ID_LEN);
3367 	se_tpg = se_sess->se_tpg;
3368 	tf_ops = se_tpg->se_tpg_tfo;
3369 	/*
3370 	 * Follow logic from spc4r17 Section 5.7.8, Table 50 --
3371 	 *	Register behaviors for a REGISTER AND MOVE service action
3372 	 *
3373 	 * Locate the existing *pr_reg via struct se_node_acl pointers
3374 	 */
3375 	pr_reg = core_scsi3_locate_pr_reg(cmd->se_dev, se_sess->se_node_acl,
3376 				se_sess);
3377 	if (!pr_reg) {
3378 		pr_err("SPC-3 PR: Unable to locate PR_REGISTERED"
3379 			" *pr_reg for REGISTER_AND_MOVE\n");
3380 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3381 		return -EINVAL;
3382 	}
3383 	/*
3384 	 * The provided reservation key much match the existing reservation key
3385 	 * provided during this initiator's I_T nexus registration.
3386 	 */
3387 	if (res_key != pr_reg->pr_res_key) {
3388 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received"
3389 			" res_key: 0x%016Lx does not match existing SA REGISTER"
3390 			" res_key: 0x%016Lx\n", res_key, pr_reg->pr_res_key);
3391 		core_scsi3_put_pr_reg(pr_reg);
3392 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3393 		return -EINVAL;
3394 	}
3395 	/*
3396 	 * The service active reservation key needs to be non zero
3397 	 */
3398 	if (!sa_res_key) {
3399 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Received zero"
3400 			" sa_res_key\n");
3401 		core_scsi3_put_pr_reg(pr_reg);
3402 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3403 		return -EINVAL;
3404 	}
3405 
3406 	/*
3407 	 * Determine the Relative Target Port Identifier where the reservation
3408 	 * will be moved to for the TransportID containing SCSI initiator WWN
3409 	 * information.
3410 	 */
3411 	buf = transport_kmap_data_sg(cmd);
3412 	rtpi = (buf[18] & 0xff) << 8;
3413 	rtpi |= buf[19] & 0xff;
3414 	tid_len = (buf[20] & 0xff) << 24;
3415 	tid_len |= (buf[21] & 0xff) << 16;
3416 	tid_len |= (buf[22] & 0xff) << 8;
3417 	tid_len |= buf[23] & 0xff;
3418 	transport_kunmap_data_sg(cmd);
3419 	buf = NULL;
3420 
3421 	if ((tid_len + 24) != cmd->data_length) {
3422 		pr_err("SPC-3 PR: Illegal tid_len: %u + 24 byte header"
3423 			" does not equal CDB data_length: %u\n", tid_len,
3424 			cmd->data_length);
3425 		core_scsi3_put_pr_reg(pr_reg);
3426 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3427 		return -EINVAL;
3428 	}
3429 
3430 	spin_lock(&dev->se_port_lock);
3431 	list_for_each_entry(se_port, &dev->dev_sep_list, sep_list) {
3432 		if (se_port->sep_rtpi != rtpi)
3433 			continue;
3434 		dest_se_tpg = se_port->sep_tpg;
3435 		if (!dest_se_tpg)
3436 			continue;
3437 		dest_tf_ops = dest_se_tpg->se_tpg_tfo;
3438 		if (!dest_tf_ops)
3439 			continue;
3440 
3441 		atomic_inc(&dest_se_tpg->tpg_pr_ref_count);
3442 		smp_mb__after_atomic_inc();
3443 		spin_unlock(&dev->se_port_lock);
3444 
3445 		ret = core_scsi3_tpg_depend_item(dest_se_tpg);
3446 		if (ret != 0) {
3447 			pr_err("core_scsi3_tpg_depend_item() failed"
3448 				" for dest_se_tpg\n");
3449 			atomic_dec(&dest_se_tpg->tpg_pr_ref_count);
3450 			smp_mb__after_atomic_dec();
3451 			core_scsi3_put_pr_reg(pr_reg);
3452 			cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3453 			return -EINVAL;
3454 		}
3455 
3456 		spin_lock(&dev->se_port_lock);
3457 		break;
3458 	}
3459 	spin_unlock(&dev->se_port_lock);
3460 
3461 	if (!dest_se_tpg || !dest_tf_ops) {
3462 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3463 			" fabric ops from Relative Target Port Identifier:"
3464 			" %hu\n", rtpi);
3465 		core_scsi3_put_pr_reg(pr_reg);
3466 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3467 		return -EINVAL;
3468 	}
3469 
3470 	buf = transport_kmap_data_sg(cmd);
3471 	proto_ident = (buf[24] & 0x0f);
3472 
3473 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Extracted Protocol Identifier:"
3474 			" 0x%02x\n", proto_ident);
3475 
3476 	if (proto_ident != dest_tf_ops->get_fabric_proto_ident(dest_se_tpg)) {
3477 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Received"
3478 			" proto_ident: 0x%02x does not match ident: 0x%02x"
3479 			" from fabric: %s\n", proto_ident,
3480 			dest_tf_ops->get_fabric_proto_ident(dest_se_tpg),
3481 			dest_tf_ops->get_fabric_name());
3482 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3483 		ret = -EINVAL;
3484 		goto out;
3485 	}
3486 	if (dest_tf_ops->tpg_parse_pr_out_transport_id == NULL) {
3487 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Fabric does not"
3488 			" containg a valid tpg_parse_pr_out_transport_id"
3489 			" function pointer\n");
3490 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3491 		ret = -EINVAL;
3492 		goto out;
3493 	}
3494 	initiator_str = dest_tf_ops->tpg_parse_pr_out_transport_id(dest_se_tpg,
3495 			(const char *)&buf[24], &tmp_tid_len, &iport_ptr);
3496 	if (!initiator_str) {
3497 		pr_err("SPC-3 PR REGISTER_AND_MOVE: Unable to locate"
3498 			" initiator_str from Transport ID\n");
3499 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3500 		ret = -EINVAL;
3501 		goto out;
3502 	}
3503 
3504 	transport_kunmap_data_sg(cmd);
3505 	buf = NULL;
3506 
3507 	pr_debug("SPC-3 PR [%s] Extracted initiator %s identifier: %s"
3508 		" %s\n", dest_tf_ops->get_fabric_name(), (iport_ptr != NULL) ?
3509 		"port" : "device", initiator_str, (iport_ptr != NULL) ?
3510 		iport_ptr : "");
3511 	/*
3512 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3513 	 * action specifies a TransportID that is the same as the initiator port
3514 	 * of the I_T nexus for the command received, then the command shall
3515 	 * be terminated with CHECK CONDITION status, with the sense key set to
3516 	 * ILLEGAL REQUEST, and the additional sense code set to INVALID FIELD
3517 	 * IN PARAMETER LIST.
3518 	 */
3519 	pr_reg_nacl = pr_reg->pr_reg_nacl;
3520 	matching_iname = (!strcmp(initiator_str,
3521 				  pr_reg_nacl->initiatorname)) ? 1 : 0;
3522 	if (!matching_iname)
3523 		goto after_iport_check;
3524 
3525 	if (!iport_ptr || !pr_reg->isid_present_at_reg) {
3526 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s"
3527 			" matches: %s on received I_T Nexus\n", initiator_str,
3528 			pr_reg_nacl->initiatorname);
3529 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3530 		ret = -EINVAL;
3531 		goto out;
3532 	}
3533 	if (!strcmp(iport_ptr, pr_reg->pr_reg_isid)) {
3534 		pr_err("SPC-3 PR REGISTER_AND_MOVE: TransportID: %s %s"
3535 			" matches: %s %s on received I_T Nexus\n",
3536 			initiator_str, iport_ptr, pr_reg_nacl->initiatorname,
3537 			pr_reg->pr_reg_isid);
3538 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3539 		ret = -EINVAL;
3540 		goto out;
3541 	}
3542 after_iport_check:
3543 	/*
3544 	 * Locate the destination struct se_node_acl from the received Transport ID
3545 	 */
3546 	spin_lock_irq(&dest_se_tpg->acl_node_lock);
3547 	dest_node_acl = __core_tpg_get_initiator_node_acl(dest_se_tpg,
3548 				initiator_str);
3549 	if (dest_node_acl) {
3550 		atomic_inc(&dest_node_acl->acl_pr_ref_count);
3551 		smp_mb__after_atomic_inc();
3552 	}
3553 	spin_unlock_irq(&dest_se_tpg->acl_node_lock);
3554 
3555 	if (!dest_node_acl) {
3556 		pr_err("Unable to locate %s dest_node_acl for"
3557 			" TransportID%s\n", dest_tf_ops->get_fabric_name(),
3558 			initiator_str);
3559 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3560 		ret = -EINVAL;
3561 		goto out;
3562 	}
3563 	ret = core_scsi3_nodeacl_depend_item(dest_node_acl);
3564 	if (ret != 0) {
3565 		pr_err("core_scsi3_nodeacl_depend_item() for"
3566 			" dest_node_acl\n");
3567 		atomic_dec(&dest_node_acl->acl_pr_ref_count);
3568 		smp_mb__after_atomic_dec();
3569 		dest_node_acl = NULL;
3570 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3571 		ret = -EINVAL;
3572 		goto out;
3573 	}
3574 
3575 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Found %s dest_node_acl:"
3576 		" %s from TransportID\n", dest_tf_ops->get_fabric_name(),
3577 		dest_node_acl->initiatorname);
3578 
3579 	/*
3580 	 * Locate the struct se_dev_entry pointer for the matching RELATIVE TARGET
3581 	 * PORT IDENTIFIER.
3582 	 */
3583 	dest_se_deve = core_get_se_deve_from_rtpi(dest_node_acl, rtpi);
3584 	if (!dest_se_deve) {
3585 		pr_err("Unable to locate %s dest_se_deve from RTPI:"
3586 			" %hu\n",  dest_tf_ops->get_fabric_name(), rtpi);
3587 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3588 		ret = -EINVAL;
3589 		goto out;
3590 	}
3591 
3592 	ret = core_scsi3_lunacl_depend_item(dest_se_deve);
3593 	if (ret < 0) {
3594 		pr_err("core_scsi3_lunacl_depend_item() failed\n");
3595 		atomic_dec(&dest_se_deve->pr_ref_count);
3596 		smp_mb__after_atomic_dec();
3597 		dest_se_deve = NULL;
3598 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3599 		ret = -EINVAL;
3600 		goto out;
3601 	}
3602 
3603 	pr_debug("SPC-3 PR REGISTER_AND_MOVE: Located %s node %s LUN"
3604 		" ACL for dest_se_deve->mapped_lun: %u\n",
3605 		dest_tf_ops->get_fabric_name(), dest_node_acl->initiatorname,
3606 		dest_se_deve->mapped_lun);
3607 
3608 	/*
3609 	 * A persistent reservation needs to already existing in order to
3610 	 * successfully complete the REGISTER_AND_MOVE service action..
3611 	 */
3612 	spin_lock(&dev->dev_reservation_lock);
3613 	pr_res_holder = dev->dev_pr_res_holder;
3614 	if (!pr_res_holder) {
3615 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: No reservation"
3616 			" currently held\n");
3617 		spin_unlock(&dev->dev_reservation_lock);
3618 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3619 		ret = -EINVAL;
3620 		goto out;
3621 	}
3622 	/*
3623 	 * The received on I_T Nexus must be the reservation holder.
3624 	 *
3625 	 * From spc4r17 section 5.7.8  Table 50 --
3626 	 * 	Register behaviors for a REGISTER AND MOVE service action
3627 	 */
3628 	if (pr_res_holder != pr_reg) {
3629 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Calling I_T"
3630 			" Nexus is not reservation holder\n");
3631 		spin_unlock(&dev->dev_reservation_lock);
3632 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3633 		ret = -EINVAL;
3634 		goto out;
3635 	}
3636 	/*
3637 	 * From spc4r17 section 5.7.8: registering and moving reservation
3638 	 *
3639 	 * If a PERSISTENT RESERVE OUT command with a REGISTER AND MOVE service
3640 	 * action is received and the established persistent reservation is a
3641 	 * Write Exclusive - All Registrants type or Exclusive Access -
3642 	 * All Registrants type reservation, then the command shall be completed
3643 	 * with RESERVATION CONFLICT status.
3644 	 */
3645 	if ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
3646 	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
3647 		pr_warn("SPC-3 PR REGISTER_AND_MOVE: Unable to move"
3648 			" reservation for type: %s\n",
3649 			core_scsi3_pr_dump_type(pr_res_holder->pr_res_type));
3650 		spin_unlock(&dev->dev_reservation_lock);
3651 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3652 		ret = -EINVAL;
3653 		goto out;
3654 	}
3655 	pr_res_nacl = pr_res_holder->pr_reg_nacl;
3656 	/*
3657 	 * b) Ignore the contents of the (received) SCOPE and TYPE fields;
3658 	 */
3659 	type = pr_res_holder->pr_res_type;
3660 	scope = pr_res_holder->pr_res_type;
3661 	/*
3662 	 * c) Associate the reservation key specified in the SERVICE ACTION
3663 	 *    RESERVATION KEY field with the I_T nexus specified as the
3664 	 *    destination of the register and move, where:
3665 	 *    A) The I_T nexus is specified by the TransportID and the
3666 	 *	 RELATIVE TARGET PORT IDENTIFIER field (see 6.14.4); and
3667 	 *    B) Regardless of the TransportID format used, the association for
3668 	 *       the initiator port is based on either the initiator port name
3669 	 *       (see 3.1.71) on SCSI transport protocols where port names are
3670 	 *       required or the initiator port identifier (see 3.1.70) on SCSI
3671 	 *       transport protocols where port names are not required;
3672 	 * d) Register the reservation key specified in the SERVICE ACTION
3673 	 *    RESERVATION KEY field;
3674 	 * e) Retain the reservation key specified in the SERVICE ACTION
3675 	 *    RESERVATION KEY field and associated information;
3676 	 *
3677 	 * Also, It is not an error for a REGISTER AND MOVE service action to
3678 	 * register an I_T nexus that is already registered with the same
3679 	 * reservation key or a different reservation key.
3680 	 */
3681 	dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3682 					iport_ptr);
3683 	if (!dest_pr_reg) {
3684 		ret = core_scsi3_alloc_registration(cmd->se_dev,
3685 				dest_node_acl, dest_se_deve, iport_ptr,
3686 				sa_res_key, 0, aptpl, 2, 1);
3687 		if (ret != 0) {
3688 			spin_unlock(&dev->dev_reservation_lock);
3689 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3690 			ret = -EINVAL;
3691 			goto out;
3692 		}
3693 		dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
3694 						iport_ptr);
3695 		new_reg = 1;
3696 	}
3697 	/*
3698 	 * f) Release the persistent reservation for the persistent reservation
3699 	 *    holder (i.e., the I_T nexus on which the
3700 	 */
3701 	__core_scsi3_complete_pro_release(dev, pr_res_nacl,
3702 			dev->dev_pr_res_holder, 0);
3703 	/*
3704 	 * g) Move the persistent reservation to the specified I_T nexus using
3705 	 *    the same scope and type as the persistent reservation released in
3706 	 *    item f); and
3707 	 */
3708 	dev->dev_pr_res_holder = dest_pr_reg;
3709 	dest_pr_reg->pr_res_holder = 1;
3710 	dest_pr_reg->pr_res_type = type;
3711 	pr_reg->pr_res_scope = scope;
3712 	prf_isid = core_pr_dump_initiator_port(pr_reg, &i_buf[0],
3713 				PR_REG_ISID_ID_LEN);
3714 	/*
3715 	 * Increment PRGeneration for existing registrations..
3716 	 */
3717 	if (!new_reg)
3718 		dest_pr_reg->pr_res_generation = pr_tmpl->pr_generation++;
3719 	spin_unlock(&dev->dev_reservation_lock);
3720 
3721 	pr_debug("SPC-3 PR [%s] Service Action: REGISTER_AND_MOVE"
3722 		" created new reservation holder TYPE: %s on object RTPI:"
3723 		" %hu  PRGeneration: 0x%08x\n", dest_tf_ops->get_fabric_name(),
3724 		core_scsi3_pr_dump_type(type), rtpi,
3725 		dest_pr_reg->pr_res_generation);
3726 	pr_debug("SPC-3 PR Successfully moved reservation from"
3727 		" %s Fabric Node: %s%s -> %s Fabric Node: %s %s\n",
3728 		tf_ops->get_fabric_name(), pr_reg_nacl->initiatorname,
3729 		(prf_isid) ? &i_buf[0] : "", dest_tf_ops->get_fabric_name(),
3730 		dest_node_acl->initiatorname, (iport_ptr != NULL) ?
3731 		iport_ptr : "");
3732 	/*
3733 	 * It is now safe to release configfs group dependencies for destination
3734 	 * of Transport ID Initiator Device/Port Identifier
3735 	 */
3736 	core_scsi3_lunacl_undepend_item(dest_se_deve);
3737 	core_scsi3_nodeacl_undepend_item(dest_node_acl);
3738 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3739 	/*
3740 	 * h) If the UNREG bit is set to one, unregister (see 5.7.11.3) the I_T
3741 	 * nexus on which PERSISTENT RESERVE OUT command was received.
3742 	 */
3743 	if (unreg) {
3744 		spin_lock(&pr_tmpl->registration_lock);
3745 		__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
3746 		spin_unlock(&pr_tmpl->registration_lock);
3747 	} else
3748 		core_scsi3_put_pr_reg(pr_reg);
3749 
3750 	/*
3751 	 * Clear the APTPL metadata if APTPL has been disabled, otherwise
3752 	 * write out the updated metadata to struct file for this SCSI device.
3753 	 */
3754 	if (!aptpl) {
3755 		pr_tmpl->pr_aptpl_active = 0;
3756 		core_scsi3_update_and_write_aptpl(cmd->se_dev, NULL, 0);
3757 		pr_debug("SPC-3 PR: Set APTPL Bit Deactivated for"
3758 				" REGISTER_AND_MOVE\n");
3759 	} else {
3760 		pr_tmpl->pr_aptpl_active = 1;
3761 		ret = core_scsi3_update_and_write_aptpl(cmd->se_dev,
3762 				&dest_pr_reg->pr_aptpl_buf[0],
3763 				pr_tmpl->pr_aptpl_buf_len);
3764 		if (!ret)
3765 			pr_debug("SPC-3 PR: Set APTPL Bit Activated for"
3766 					" REGISTER_AND_MOVE\n");
3767 	}
3768 
3769 	transport_kunmap_data_sg(cmd);
3770 
3771 	core_scsi3_put_pr_reg(dest_pr_reg);
3772 	return 0;
3773 out:
3774 	if (buf)
3775 		transport_kunmap_data_sg(cmd);
3776 	if (dest_se_deve)
3777 		core_scsi3_lunacl_undepend_item(dest_se_deve);
3778 	if (dest_node_acl)
3779 		core_scsi3_nodeacl_undepend_item(dest_node_acl);
3780 	core_scsi3_tpg_undepend_item(dest_se_tpg);
3781 	core_scsi3_put_pr_reg(pr_reg);
3782 	return ret;
3783 }
3784 
3785 static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
3786 {
3787 	unsigned int __v1, __v2;
3788 
3789 	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
3790 	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
3791 
3792 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
3793 }
3794 
3795 /*
3796  * See spc4r17 section 6.14 Table 170
3797  */
3798 int target_scsi3_emulate_pr_out(struct se_cmd *cmd)
3799 {
3800 	unsigned char *cdb = &cmd->t_task_cdb[0];
3801 	unsigned char *buf;
3802 	u64 res_key, sa_res_key;
3803 	int sa, scope, type, aptpl;
3804 	int spec_i_pt = 0, all_tg_pt = 0, unreg = 0;
3805 	int ret;
3806 
3807 	/*
3808 	 * Following spc2r20 5.5.1 Reservations overview:
3809 	 *
3810 	 * If a logical unit has been reserved by any RESERVE command and is
3811 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
3812 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
3813 	 * initiator or service action and shall terminate with a RESERVATION
3814 	 * CONFLICT status.
3815 	 */
3816 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS) {
3817 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
3818 			" SPC-2 reservation is held, returning"
3819 			" RESERVATION_CONFLICT\n");
3820 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
3821 		ret = -EINVAL;
3822 		goto out;
3823 	}
3824 
3825 	/*
3826 	 * FIXME: A NULL struct se_session pointer means an this is not coming from
3827 	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
3828 	 */
3829 	if (!cmd->se_sess) {
3830 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
3831 		ret = -EINVAL;
3832 		goto out;
3833 	}
3834 
3835 	if (cmd->data_length < 24) {
3836 		pr_warn("SPC-PR: Received PR OUT parameter list"
3837 			" length too small: %u\n", cmd->data_length);
3838 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3839 		ret = -EINVAL;
3840 		goto out;
3841 	}
3842 	/*
3843 	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
3844 	 */
3845 	sa = (cdb[1] & 0x1f);
3846 	scope = (cdb[2] & 0xf0);
3847 	type = (cdb[2] & 0x0f);
3848 
3849 	buf = transport_kmap_data_sg(cmd);
3850 	/*
3851 	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
3852 	 */
3853 	res_key = core_scsi3_extract_reservation_key(&buf[0]);
3854 	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
3855 	/*
3856 	 * REGISTER_AND_MOVE uses a different SA parameter list containing
3857 	 * SCSI TransportIDs.
3858 	 */
3859 	if (sa != PRO_REGISTER_AND_MOVE) {
3860 		spec_i_pt = (buf[20] & 0x08);
3861 		all_tg_pt = (buf[20] & 0x04);
3862 		aptpl = (buf[20] & 0x01);
3863 	} else {
3864 		aptpl = (buf[17] & 0x01);
3865 		unreg = (buf[17] & 0x02);
3866 	}
3867 	transport_kunmap_data_sg(cmd);
3868 	buf = NULL;
3869 
3870 	/*
3871 	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
3872 	 */
3873 	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER)) {
3874 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3875 		ret = -EINVAL;
3876 		goto out;
3877 	}
3878 
3879 	/*
3880 	 * From spc4r17 section 6.14:
3881 	 *
3882 	 * If the SPEC_I_PT bit is set to zero, the service action is not
3883 	 * REGISTER AND MOVE, and the parameter list length is not 24, then
3884 	 * the command shall be terminated with CHECK CONDITION status, with
3885 	 * the sense key set to ILLEGAL REQUEST, and the additional sense
3886 	 * code set to PARAMETER LIST LENGTH ERROR.
3887 	 */
3888 	if (!spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER_AND_MOVE) &&
3889 	    (cmd->data_length != 24)) {
3890 		pr_warn("SPC-PR: Received PR OUT illegal parameter"
3891 			" list length: %u\n", cmd->data_length);
3892 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
3893 		ret = -EINVAL;
3894 		goto out;
3895 	}
3896 	/*
3897 	 * (core_scsi3_emulate_pro_* function parameters
3898 	 * are defined by spc4r17 Table 174:
3899 	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
3900 	 */
3901 	switch (sa) {
3902 	case PRO_REGISTER:
3903 		ret = core_scsi3_emulate_pro_register(cmd,
3904 			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 0);
3905 		break;
3906 	case PRO_RESERVE:
3907 		ret = core_scsi3_emulate_pro_reserve(cmd, type, scope, res_key);
3908 		break;
3909 	case PRO_RELEASE:
3910 		ret = core_scsi3_emulate_pro_release(cmd, type, scope, res_key);
3911 		break;
3912 	case PRO_CLEAR:
3913 		ret = core_scsi3_emulate_pro_clear(cmd, res_key);
3914 		break;
3915 	case PRO_PREEMPT:
3916 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3917 					res_key, sa_res_key, 0);
3918 		break;
3919 	case PRO_PREEMPT_AND_ABORT:
3920 		ret = core_scsi3_emulate_pro_preempt(cmd, type, scope,
3921 					res_key, sa_res_key, 1);
3922 		break;
3923 	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
3924 		ret = core_scsi3_emulate_pro_register(cmd,
3925 			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 1);
3926 		break;
3927 	case PRO_REGISTER_AND_MOVE:
3928 		ret = core_scsi3_emulate_pro_register_and_move(cmd, res_key,
3929 				sa_res_key, aptpl, unreg);
3930 		break;
3931 	default:
3932 		pr_err("Unknown PERSISTENT_RESERVE_OUT service"
3933 			" action: 0x%02x\n", cdb[1] & 0x1f);
3934 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3935 		ret = -EINVAL;
3936 		break;
3937 	}
3938 
3939 out:
3940 	if (!ret)
3941 		target_complete_cmd(cmd, GOOD);
3942 	return ret;
3943 }
3944 
3945 /*
3946  * PERSISTENT_RESERVE_IN Service Action READ_KEYS
3947  *
3948  * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
3949  */
3950 static int core_scsi3_pri_read_keys(struct se_cmd *cmd)
3951 {
3952 	struct se_device *se_dev = cmd->se_dev;
3953 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
3954 	struct t10_pr_registration *pr_reg;
3955 	unsigned char *buf;
3956 	u32 add_len = 0, off = 8;
3957 
3958 	if (cmd->data_length < 8) {
3959 		pr_err("PRIN SA READ_KEYS SCSI Data Length: %u"
3960 			" too small\n", cmd->data_length);
3961 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
3962 		return -EINVAL;
3963 	}
3964 
3965 	buf = transport_kmap_data_sg(cmd);
3966 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
3967 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
3968 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
3969 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
3970 
3971 	spin_lock(&su_dev->t10_pr.registration_lock);
3972 	list_for_each_entry(pr_reg, &su_dev->t10_pr.registration_list,
3973 			pr_reg_list) {
3974 		/*
3975 		 * Check for overflow of 8byte PRI READ_KEYS payload and
3976 		 * next reservation key list descriptor.
3977 		 */
3978 		if ((add_len + 8) > (cmd->data_length - 8))
3979 			break;
3980 
3981 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
3982 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
3983 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
3984 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
3985 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
3986 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
3987 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
3988 		buf[off++] = (pr_reg->pr_res_key & 0xff);
3989 
3990 		add_len += 8;
3991 	}
3992 	spin_unlock(&su_dev->t10_pr.registration_lock);
3993 
3994 	buf[4] = ((add_len >> 24) & 0xff);
3995 	buf[5] = ((add_len >> 16) & 0xff);
3996 	buf[6] = ((add_len >> 8) & 0xff);
3997 	buf[7] = (add_len & 0xff);
3998 
3999 	transport_kunmap_data_sg(cmd);
4000 
4001 	return 0;
4002 }
4003 
4004 /*
4005  * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
4006  *
4007  * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
4008  */
4009 static int core_scsi3_pri_read_reservation(struct se_cmd *cmd)
4010 {
4011 	struct se_device *se_dev = cmd->se_dev;
4012 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
4013 	struct t10_pr_registration *pr_reg;
4014 	unsigned char *buf;
4015 	u64 pr_res_key;
4016 	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
4017 
4018 	if (cmd->data_length < 8) {
4019 		pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
4020 			" too small\n", cmd->data_length);
4021 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4022 		return -EINVAL;
4023 	}
4024 
4025 	buf = transport_kmap_data_sg(cmd);
4026 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
4027 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
4028 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
4029 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
4030 
4031 	spin_lock(&se_dev->dev_reservation_lock);
4032 	pr_reg = se_dev->dev_pr_res_holder;
4033 	if (pr_reg) {
4034 		/*
4035 		 * Set the hardcoded Additional Length
4036 		 */
4037 		buf[4] = ((add_len >> 24) & 0xff);
4038 		buf[5] = ((add_len >> 16) & 0xff);
4039 		buf[6] = ((add_len >> 8) & 0xff);
4040 		buf[7] = (add_len & 0xff);
4041 
4042 		if (cmd->data_length < 22)
4043 			goto err;
4044 
4045 		/*
4046 		 * Set the Reservation key.
4047 		 *
4048 		 * From spc4r17, section 5.7.10:
4049 		 * A persistent reservation holder has its reservation key
4050 		 * returned in the parameter data from a PERSISTENT
4051 		 * RESERVE IN command with READ RESERVATION service action as
4052 		 * follows:
4053 		 * a) For a persistent reservation of the type Write Exclusive
4054 		 *    - All Registrants or Exclusive Access ­ All Regitrants,
4055 		 *      the reservation key shall be set to zero; or
4056 		 * b) For all other persistent reservation types, the
4057 		 *    reservation key shall be set to the registered
4058 		 *    reservation key for the I_T nexus that holds the
4059 		 *    persistent reservation.
4060 		 */
4061 		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
4062 		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
4063 			pr_res_key = 0;
4064 		else
4065 			pr_res_key = pr_reg->pr_res_key;
4066 
4067 		buf[8] = ((pr_res_key >> 56) & 0xff);
4068 		buf[9] = ((pr_res_key >> 48) & 0xff);
4069 		buf[10] = ((pr_res_key >> 40) & 0xff);
4070 		buf[11] = ((pr_res_key >> 32) & 0xff);
4071 		buf[12] = ((pr_res_key >> 24) & 0xff);
4072 		buf[13] = ((pr_res_key >> 16) & 0xff);
4073 		buf[14] = ((pr_res_key >> 8) & 0xff);
4074 		buf[15] = (pr_res_key & 0xff);
4075 		/*
4076 		 * Set the SCOPE and TYPE
4077 		 */
4078 		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
4079 			  (pr_reg->pr_res_type & 0x0f);
4080 	}
4081 
4082 err:
4083 	spin_unlock(&se_dev->dev_reservation_lock);
4084 	transport_kunmap_data_sg(cmd);
4085 
4086 	return 0;
4087 }
4088 
4089 /*
4090  * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
4091  *
4092  * See spc4r17 section 6.13.4 Table 165
4093  */
4094 static int core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
4095 {
4096 	struct se_device *dev = cmd->se_dev;
4097 	struct t10_reservation *pr_tmpl = &dev->se_sub_dev->t10_pr;
4098 	unsigned char *buf;
4099 	u16 add_len = 8; /* Hardcoded to 8. */
4100 
4101 	if (cmd->data_length < 6) {
4102 		pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
4103 			" %u too small\n", cmd->data_length);
4104 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4105 		return -EINVAL;
4106 	}
4107 
4108 	buf = transport_kmap_data_sg(cmd);
4109 
4110 	buf[0] = ((add_len << 8) & 0xff);
4111 	buf[1] = (add_len & 0xff);
4112 	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
4113 	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
4114 	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
4115 	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
4116 	/*
4117 	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
4118 	 * set the TMV: Task Mask Valid bit.
4119 	 */
4120 	buf[3] |= 0x80;
4121 	/*
4122 	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
4123 	 */
4124 	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
4125 	/*
4126 	 * PTPL_A: Persistence across Target Power Loss Active bit
4127 	 */
4128 	if (pr_tmpl->pr_aptpl_active)
4129 		buf[3] |= 0x01;
4130 	/*
4131 	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
4132 	 */
4133 	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4134 	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
4135 	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
4136 	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
4137 	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
4138 	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
4139 
4140 	transport_kunmap_data_sg(cmd);
4141 
4142 	return 0;
4143 }
4144 
4145 /*
4146  * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
4147  *
4148  * See spc4r17 section 6.13.5 Table 168 and 169
4149  */
4150 static int core_scsi3_pri_read_full_status(struct se_cmd *cmd)
4151 {
4152 	struct se_device *se_dev = cmd->se_dev;
4153 	struct se_node_acl *se_nacl;
4154 	struct se_subsystem_dev *su_dev = se_dev->se_sub_dev;
4155 	struct se_portal_group *se_tpg;
4156 	struct t10_pr_registration *pr_reg, *pr_reg_tmp;
4157 	struct t10_reservation *pr_tmpl = &se_dev->se_sub_dev->t10_pr;
4158 	unsigned char *buf;
4159 	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
4160 	u32 off = 8; /* off into first Full Status descriptor */
4161 	int format_code = 0;
4162 
4163 	if (cmd->data_length < 8) {
4164 		pr_err("PRIN SA READ_FULL_STATUS SCSI Data Length: %u"
4165 			" too small\n", cmd->data_length);
4166 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4167 		return -EINVAL;
4168 	}
4169 
4170 	buf = transport_kmap_data_sg(cmd);
4171 
4172 	buf[0] = ((su_dev->t10_pr.pr_generation >> 24) & 0xff);
4173 	buf[1] = ((su_dev->t10_pr.pr_generation >> 16) & 0xff);
4174 	buf[2] = ((su_dev->t10_pr.pr_generation >> 8) & 0xff);
4175 	buf[3] = (su_dev->t10_pr.pr_generation & 0xff);
4176 
4177 	spin_lock(&pr_tmpl->registration_lock);
4178 	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
4179 			&pr_tmpl->registration_list, pr_reg_list) {
4180 
4181 		se_nacl = pr_reg->pr_reg_nacl;
4182 		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
4183 		add_desc_len = 0;
4184 
4185 		atomic_inc(&pr_reg->pr_res_holders);
4186 		smp_mb__after_atomic_inc();
4187 		spin_unlock(&pr_tmpl->registration_lock);
4188 		/*
4189 		 * Determine expected length of $FABRIC_MOD specific
4190 		 * TransportID full status descriptor..
4191 		 */
4192 		exp_desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id_len(
4193 				se_tpg, se_nacl, pr_reg, &format_code);
4194 
4195 		if ((exp_desc_len + add_len) > cmd->data_length) {
4196 			pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
4197 				" out of buffer: %d\n", cmd->data_length);
4198 			spin_lock(&pr_tmpl->registration_lock);
4199 			atomic_dec(&pr_reg->pr_res_holders);
4200 			smp_mb__after_atomic_dec();
4201 			break;
4202 		}
4203 		/*
4204 		 * Set RESERVATION KEY
4205 		 */
4206 		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
4207 		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
4208 		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
4209 		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
4210 		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
4211 		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
4212 		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
4213 		buf[off++] = (pr_reg->pr_res_key & 0xff);
4214 		off += 4; /* Skip Over Reserved area */
4215 
4216 		/*
4217 		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
4218 		 */
4219 		if (pr_reg->pr_reg_all_tg_pt)
4220 			buf[off] = 0x02;
4221 		/*
4222 		 * The struct se_lun pointer will be present for the
4223 		 * reservation holder for PR_HOLDER bit.
4224 		 *
4225 		 * Also, if this registration is the reservation
4226 		 * holder, fill in SCOPE and TYPE in the next byte.
4227 		 */
4228 		if (pr_reg->pr_res_holder) {
4229 			buf[off++] |= 0x01;
4230 			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
4231 				     (pr_reg->pr_res_type & 0x0f);
4232 		} else
4233 			off += 2;
4234 
4235 		off += 4; /* Skip over reserved area */
4236 		/*
4237 		 * From spc4r17 6.3.15:
4238 		 *
4239 		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
4240 		 * IDENTIFIER field contains the relative port identifier (see
4241 		 * 3.1.120) of the target port that is part of the I_T nexus
4242 		 * described by this full status descriptor. If the ALL_TG_PT
4243 		 * bit is set to one, the contents of the RELATIVE TARGET PORT
4244 		 * IDENTIFIER field are not defined by this standard.
4245 		 */
4246 		if (!pr_reg->pr_reg_all_tg_pt) {
4247 			struct se_port *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
4248 
4249 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
4250 			buf[off++] = (port->sep_rtpi & 0xff);
4251 		} else
4252 			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFER */
4253 
4254 		/*
4255 		 * Now, have the $FABRIC_MOD fill in the protocol identifier
4256 		 */
4257 		desc_len = se_tpg->se_tpg_tfo->tpg_get_pr_transport_id(se_tpg,
4258 				se_nacl, pr_reg, &format_code, &buf[off+4]);
4259 
4260 		spin_lock(&pr_tmpl->registration_lock);
4261 		atomic_dec(&pr_reg->pr_res_holders);
4262 		smp_mb__after_atomic_dec();
4263 		/*
4264 		 * Set the ADDITIONAL DESCRIPTOR LENGTH
4265 		 */
4266 		buf[off++] = ((desc_len >> 24) & 0xff);
4267 		buf[off++] = ((desc_len >> 16) & 0xff);
4268 		buf[off++] = ((desc_len >> 8) & 0xff);
4269 		buf[off++] = (desc_len & 0xff);
4270 		/*
4271 		 * Size of full desctipor header minus TransportID
4272 		 * containing $FABRIC_MOD specific) initiator device/port
4273 		 * WWN information.
4274 		 *
4275 		 *  See spc4r17 Section 6.13.5 Table 169
4276 		 */
4277 		add_desc_len = (24 + desc_len);
4278 
4279 		off += desc_len;
4280 		add_len += add_desc_len;
4281 	}
4282 	spin_unlock(&pr_tmpl->registration_lock);
4283 	/*
4284 	 * Set ADDITIONAL_LENGTH
4285 	 */
4286 	buf[4] = ((add_len >> 24) & 0xff);
4287 	buf[5] = ((add_len >> 16) & 0xff);
4288 	buf[6] = ((add_len >> 8) & 0xff);
4289 	buf[7] = (add_len & 0xff);
4290 
4291 	transport_kunmap_data_sg(cmd);
4292 
4293 	return 0;
4294 }
4295 
4296 int target_scsi3_emulate_pr_in(struct se_cmd *cmd)
4297 {
4298 	int ret;
4299 
4300 	/*
4301 	 * Following spc2r20 5.5.1 Reservations overview:
4302 	 *
4303 	 * If a logical unit has been reserved by any RESERVE command and is
4304 	 * still reserved by any initiator, all PERSISTENT RESERVE IN and all
4305 	 * PERSISTENT RESERVE OUT commands shall conflict regardless of
4306 	 * initiator or service action and shall terminate with a RESERVATION
4307 	 * CONFLICT status.
4308 	 */
4309 	if (cmd->se_dev->dev_flags & DF_SPC2_RESERVATIONS) {
4310 		pr_err("Received PERSISTENT_RESERVE CDB while legacy"
4311 			" SPC-2 reservation is held, returning"
4312 			" RESERVATION_CONFLICT\n");
4313 		cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
4314 		return -EINVAL;
4315 	}
4316 
4317 	switch (cmd->t_task_cdb[1] & 0x1f) {
4318 	case PRI_READ_KEYS:
4319 		ret = core_scsi3_pri_read_keys(cmd);
4320 		break;
4321 	case PRI_READ_RESERVATION:
4322 		ret = core_scsi3_pri_read_reservation(cmd);
4323 		break;
4324 	case PRI_REPORT_CAPABILITIES:
4325 		ret = core_scsi3_pri_report_capabilities(cmd);
4326 		break;
4327 	case PRI_READ_FULL_STATUS:
4328 		ret = core_scsi3_pri_read_full_status(cmd);
4329 		break;
4330 	default:
4331 		pr_err("Unknown PERSISTENT_RESERVE_IN service"
4332 			" action: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f);
4333 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
4334 		ret = -EINVAL;
4335 		break;
4336 	}
4337 
4338 	if (!ret)
4339 		target_complete_cmd(cmd, GOOD);
4340 	return ret;
4341 }
4342 
4343 static int core_pt_reservation_check(struct se_cmd *cmd, u32 *pr_res_type)
4344 {
4345 	return 0;
4346 }
4347 
4348 static int core_pt_seq_non_holder(
4349 	struct se_cmd *cmd,
4350 	unsigned char *cdb,
4351 	u32 pr_reg_type)
4352 {
4353 	return 0;
4354 }
4355 
4356 int core_setup_reservations(struct se_device *dev, int force_pt)
4357 {
4358 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
4359 	struct t10_reservation *rest = &su_dev->t10_pr;
4360 	/*
4361 	 * If this device is from Target_Core_Mod/pSCSI, use the reservations
4362 	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
4363 	 * cause a problem because libata and some SATA RAID HBAs appear
4364 	 * under Linux/SCSI, but to emulate reservations themselves.
4365 	 */
4366 	if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
4367 	    !(dev->se_sub_dev->se_dev_attrib.emulate_reservations)) || force_pt) {
4368 		rest->res_type = SPC_PASSTHROUGH;
4369 		rest->pr_ops.t10_reservation_check = &core_pt_reservation_check;
4370 		rest->pr_ops.t10_seq_non_holder = &core_pt_seq_non_holder;
4371 		pr_debug("%s: Using SPC_PASSTHROUGH, no reservation"
4372 			" emulation\n", dev->transport->name);
4373 		return 0;
4374 	}
4375 	/*
4376 	 * If SPC-3 or above is reported by real or emulated struct se_device,
4377 	 * use emulated Persistent Reservations.
4378 	 */
4379 	if (dev->transport->get_device_rev(dev) >= SCSI_3) {
4380 		rest->res_type = SPC3_PERSISTENT_RESERVATIONS;
4381 		rest->pr_ops.t10_reservation_check = &core_scsi3_pr_reservation_check;
4382 		rest->pr_ops.t10_seq_non_holder = &core_scsi3_pr_seq_non_holder;
4383 		pr_debug("%s: Using SPC3_PERSISTENT_RESERVATIONS"
4384 			" emulation\n", dev->transport->name);
4385 	} else {
4386 		rest->res_type = SPC2_RESERVATIONS;
4387 		rest->pr_ops.t10_reservation_check = &core_scsi2_reservation_check;
4388 		rest->pr_ops.t10_seq_non_holder =
4389 				&core_scsi2_reservation_seq_non_holder;
4390 		pr_debug("%s: Using SPC2_RESERVATIONS emulation\n",
4391 			dev->transport->name);
4392 	}
4393 
4394 	return 0;
4395 }
4396