1 /*******************************************************************************
2  * Filename:  target_core_alua.c
3  *
4  * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
5  *
6  * (c) Copyright 2009-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <linux/configfs.h>
29 #include <linux/delay.h>
30 #include <linux/export.h>
31 #include <linux/fcntl.h>
32 #include <linux/file.h>
33 #include <linux/fs.h>
34 #include <scsi/scsi_proto.h>
35 #include <asm/unaligned.h>
36 
37 #include <target/target_core_base.h>
38 #include <target/target_core_backend.h>
39 #include <target/target_core_fabric.h>
40 
41 #include "target_core_internal.h"
42 #include "target_core_alua.h"
43 #include "target_core_ua.h"
44 
45 static sense_reason_t core_alua_check_transition(int state, int valid,
46 						 int *primary, int explicit);
47 static int core_alua_set_tg_pt_secondary_state(
48 		struct se_lun *lun, int explicit, int offline);
49 
50 static char *core_alua_dump_state(int state);
51 
52 static void __target_attach_tg_pt_gp(struct se_lun *lun,
53 		struct t10_alua_tg_pt_gp *tg_pt_gp);
54 
55 static u16 alua_lu_gps_counter;
56 static u32 alua_lu_gps_count;
57 
58 static DEFINE_SPINLOCK(lu_gps_lock);
59 static LIST_HEAD(lu_gps_list);
60 
61 struct t10_alua_lu_gp *default_lu_gp;
62 
63 /*
64  * REPORT REFERRALS
65  *
66  * See sbc3r35 section 5.23
67  */
68 sense_reason_t
69 target_emulate_report_referrals(struct se_cmd *cmd)
70 {
71 	struct se_device *dev = cmd->se_dev;
72 	struct t10_alua_lba_map *map;
73 	struct t10_alua_lba_map_member *map_mem;
74 	unsigned char *buf;
75 	u32 rd_len = 0, off;
76 
77 	if (cmd->data_length < 4) {
78 		pr_warn("REPORT REFERRALS allocation length %u too"
79 			" small\n", cmd->data_length);
80 		return TCM_INVALID_CDB_FIELD;
81 	}
82 
83 	buf = transport_kmap_data_sg(cmd);
84 	if (!buf)
85 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
86 
87 	off = 4;
88 	spin_lock(&dev->t10_alua.lba_map_lock);
89 	if (list_empty(&dev->t10_alua.lba_map_list)) {
90 		spin_unlock(&dev->t10_alua.lba_map_lock);
91 		transport_kunmap_data_sg(cmd);
92 
93 		return TCM_UNSUPPORTED_SCSI_OPCODE;
94 	}
95 
96 	list_for_each_entry(map, &dev->t10_alua.lba_map_list,
97 			    lba_map_list) {
98 		int desc_num = off + 3;
99 		int pg_num;
100 
101 		off += 4;
102 		if (cmd->data_length > off)
103 			put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
104 		off += 8;
105 		if (cmd->data_length > off)
106 			put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
107 		off += 8;
108 		rd_len += 20;
109 		pg_num = 0;
110 		list_for_each_entry(map_mem, &map->lba_map_mem_list,
111 				    lba_map_mem_list) {
112 			int alua_state = map_mem->lba_map_mem_alua_state;
113 			int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;
114 
115 			if (cmd->data_length > off)
116 				buf[off] = alua_state & 0x0f;
117 			off += 2;
118 			if (cmd->data_length > off)
119 				buf[off] = (alua_pg_id >> 8) & 0xff;
120 			off++;
121 			if (cmd->data_length > off)
122 				buf[off] = (alua_pg_id & 0xff);
123 			off++;
124 			rd_len += 4;
125 			pg_num++;
126 		}
127 		if (cmd->data_length > desc_num)
128 			buf[desc_num] = pg_num;
129 	}
130 	spin_unlock(&dev->t10_alua.lba_map_lock);
131 
132 	/*
133 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
134 	 */
135 	put_unaligned_be16(rd_len, &buf[2]);
136 
137 	transport_kunmap_data_sg(cmd);
138 
139 	target_complete_cmd(cmd, GOOD);
140 	return 0;
141 }
142 
143 /*
144  * REPORT_TARGET_PORT_GROUPS
145  *
146  * See spc4r17 section 6.27
147  */
148 sense_reason_t
149 target_emulate_report_target_port_groups(struct se_cmd *cmd)
150 {
151 	struct se_device *dev = cmd->se_dev;
152 	struct t10_alua_tg_pt_gp *tg_pt_gp;
153 	struct se_lun *lun;
154 	unsigned char *buf;
155 	u32 rd_len = 0, off;
156 	int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
157 
158 	/*
159 	 * Skip over RESERVED area to first Target port group descriptor
160 	 * depending on the PARAMETER DATA FORMAT type..
161 	 */
162 	if (ext_hdr != 0)
163 		off = 8;
164 	else
165 		off = 4;
166 
167 	if (cmd->data_length < off) {
168 		pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
169 			" small for %s header\n", cmd->data_length,
170 			(ext_hdr) ? "extended" : "normal");
171 		return TCM_INVALID_CDB_FIELD;
172 	}
173 	buf = transport_kmap_data_sg(cmd);
174 	if (!buf)
175 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
176 
177 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
178 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
179 			tg_pt_gp_list) {
180 		/*
181 		 * Check if the Target port group and Target port descriptor list
182 		 * based on tg_pt_gp_members count will fit into the response payload.
183 		 * Otherwise, bump rd_len to let the initiator know we have exceeded
184 		 * the allocation length and the response is truncated.
185 		 */
186 		if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
187 		     cmd->data_length) {
188 			rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
189 			continue;
190 		}
191 		/*
192 		 * PREF: Preferred target port bit, determine if this
193 		 * bit should be set for port group.
194 		 */
195 		if (tg_pt_gp->tg_pt_gp_pref)
196 			buf[off] = 0x80;
197 		/*
198 		 * Set the ASYMMETRIC ACCESS State
199 		 */
200 		buf[off++] |= (atomic_read(
201 			&tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
202 		/*
203 		 * Set supported ASYMMETRIC ACCESS State bits
204 		 */
205 		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
206 		/*
207 		 * TARGET PORT GROUP
208 		 */
209 		buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
210 		buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
211 
212 		off++; /* Skip over Reserved */
213 		/*
214 		 * STATUS CODE
215 		 */
216 		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
217 		/*
218 		 * Vendor Specific field
219 		 */
220 		buf[off++] = 0x00;
221 		/*
222 		 * TARGET PORT COUNT
223 		 */
224 		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
225 		rd_len += 8;
226 
227 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
228 		list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
229 				lun_tg_pt_gp_link) {
230 			/*
231 			 * Start Target Port descriptor format
232 			 *
233 			 * See spc4r17 section 6.2.7 Table 247
234 			 */
235 			off += 2; /* Skip over Obsolete */
236 			/*
237 			 * Set RELATIVE TARGET PORT IDENTIFIER
238 			 */
239 			buf[off++] = ((lun->lun_rtpi >> 8) & 0xff);
240 			buf[off++] = (lun->lun_rtpi & 0xff);
241 			rd_len += 4;
242 		}
243 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
244 	}
245 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
246 	/*
247 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
248 	 */
249 	put_unaligned_be32(rd_len, &buf[0]);
250 
251 	/*
252 	 * Fill in the Extended header parameter data format if requested
253 	 */
254 	if (ext_hdr != 0) {
255 		buf[4] = 0x10;
256 		/*
257 		 * Set the implicit transition time (in seconds) for the application
258 		 * client to use as a base for it's transition timeout value.
259 		 *
260 		 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
261 		 * this CDB was received upon to determine this value individually
262 		 * for ALUA target port group.
263 		 */
264 		spin_lock(&cmd->se_lun->lun_tg_pt_gp_lock);
265 		tg_pt_gp = cmd->se_lun->lun_tg_pt_gp;
266 		if (tg_pt_gp)
267 			buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
268 		spin_unlock(&cmd->se_lun->lun_tg_pt_gp_lock);
269 	}
270 	transport_kunmap_data_sg(cmd);
271 
272 	target_complete_cmd(cmd, GOOD);
273 	return 0;
274 }
275 
276 /*
277  * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
278  *
279  * See spc4r17 section 6.35
280  */
281 sense_reason_t
282 target_emulate_set_target_port_groups(struct se_cmd *cmd)
283 {
284 	struct se_device *dev = cmd->se_dev;
285 	struct se_lun *l_lun = cmd->se_lun;
286 	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
287 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
288 	unsigned char *buf;
289 	unsigned char *ptr;
290 	sense_reason_t rc = TCM_NO_SENSE;
291 	u32 len = 4; /* Skip over RESERVED area in header */
292 	int alua_access_state, primary = 0, valid_states;
293 	u16 tg_pt_id, rtpi;
294 
295 	if (cmd->data_length < 4) {
296 		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
297 			" small\n", cmd->data_length);
298 		return TCM_INVALID_PARAMETER_LIST;
299 	}
300 
301 	buf = transport_kmap_data_sg(cmd);
302 	if (!buf)
303 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
304 
305 	/*
306 	 * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
307 	 * for the local tg_pt_gp.
308 	 */
309 	spin_lock(&l_lun->lun_tg_pt_gp_lock);
310 	l_tg_pt_gp = l_lun->lun_tg_pt_gp;
311 	if (!l_tg_pt_gp) {
312 		spin_unlock(&l_lun->lun_tg_pt_gp_lock);
313 		pr_err("Unable to access l_lun->tg_pt_gp\n");
314 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
315 		goto out;
316 	}
317 
318 	if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
319 		spin_unlock(&l_lun->lun_tg_pt_gp_lock);
320 		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
321 				" while TPGS_EXPLICIT_ALUA is disabled\n");
322 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
323 		goto out;
324 	}
325 	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
326 	spin_unlock(&l_lun->lun_tg_pt_gp_lock);
327 
328 	ptr = &buf[4]; /* Skip over RESERVED area in header */
329 
330 	while (len < cmd->data_length) {
331 		bool found = false;
332 		alua_access_state = (ptr[0] & 0x0f);
333 		/*
334 		 * Check the received ALUA access state, and determine if
335 		 * the state is a primary or secondary target port asymmetric
336 		 * access state.
337 		 */
338 		rc = core_alua_check_transition(alua_access_state, valid_states,
339 						&primary, 1);
340 		if (rc) {
341 			/*
342 			 * If the SET TARGET PORT GROUPS attempts to establish
343 			 * an invalid combination of target port asymmetric
344 			 * access states or attempts to establish an
345 			 * unsupported target port asymmetric access state,
346 			 * then the command shall be terminated with CHECK
347 			 * CONDITION status, with the sense key set to ILLEGAL
348 			 * REQUEST, and the additional sense code set to INVALID
349 			 * FIELD IN PARAMETER LIST.
350 			 */
351 			goto out;
352 		}
353 
354 		/*
355 		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
356 		 * specifies a primary target port asymmetric access state,
357 		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
358 		 * a primary target port group for which the primary target
359 		 * port asymmetric access state shall be changed. If the
360 		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
361 		 * port asymmetric access state, then the TARGET PORT GROUP OR
362 		 * TARGET PORT field specifies the relative target port
363 		 * identifier (see 3.1.120) of the target port for which the
364 		 * secondary target port asymmetric access state shall be
365 		 * changed.
366 		 */
367 		if (primary) {
368 			tg_pt_id = get_unaligned_be16(ptr + 2);
369 			/*
370 			 * Locate the matching target port group ID from
371 			 * the global tg_pt_gp list
372 			 */
373 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
374 			list_for_each_entry(tg_pt_gp,
375 					&dev->t10_alua.tg_pt_gps_list,
376 					tg_pt_gp_list) {
377 				if (!tg_pt_gp->tg_pt_gp_valid_id)
378 					continue;
379 
380 				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
381 					continue;
382 
383 				atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
384 
385 				spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
386 
387 				if (!core_alua_do_port_transition(tg_pt_gp,
388 						dev, l_lun, nacl,
389 						alua_access_state, 1))
390 					found = true;
391 
392 				spin_lock(&dev->t10_alua.tg_pt_gps_lock);
393 				atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
394 				break;
395 			}
396 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
397 		} else {
398 			struct se_lun *lun;
399 
400 			/*
401 			 * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
402 			 * the Target Port in question for the the incoming
403 			 * SET_TARGET_PORT_GROUPS op.
404 			 */
405 			rtpi = get_unaligned_be16(ptr + 2);
406 			/*
407 			 * Locate the matching relative target port identifier
408 			 * for the struct se_device storage object.
409 			 */
410 			spin_lock(&dev->se_port_lock);
411 			list_for_each_entry(lun, &dev->dev_sep_list,
412 							lun_dev_link) {
413 				if (lun->lun_rtpi != rtpi)
414 					continue;
415 
416 				// XXX: racy unlock
417 				spin_unlock(&dev->se_port_lock);
418 
419 				if (!core_alua_set_tg_pt_secondary_state(
420 						lun, 1, 1))
421 					found = true;
422 
423 				spin_lock(&dev->se_port_lock);
424 				break;
425 			}
426 			spin_unlock(&dev->se_port_lock);
427 		}
428 
429 		if (!found) {
430 			rc = TCM_INVALID_PARAMETER_LIST;
431 			goto out;
432 		}
433 
434 		ptr += 4;
435 		len += 4;
436 	}
437 
438 out:
439 	transport_kunmap_data_sg(cmd);
440 	if (!rc)
441 		target_complete_cmd(cmd, GOOD);
442 	return rc;
443 }
444 
445 static inline void set_ascq(struct se_cmd *cmd, u8 alua_ascq)
446 {
447 	/*
448 	 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
449 	 * The ALUA additional sense code qualifier (ASCQ) is determined
450 	 * by the ALUA primary or secondary access state..
451 	 */
452 	pr_debug("[%s]: ALUA TG Port not available, "
453 		"SenseKey: NOT_READY, ASC/ASCQ: "
454 		"0x04/0x%02x\n",
455 		cmd->se_tfo->get_fabric_name(), alua_ascq);
456 
457 	cmd->scsi_asc = 0x04;
458 	cmd->scsi_ascq = alua_ascq;
459 }
460 
461 static inline void core_alua_state_nonoptimized(
462 	struct se_cmd *cmd,
463 	unsigned char *cdb,
464 	int nonop_delay_msecs)
465 {
466 	/*
467 	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
468 	 * later to determine if processing of this cmd needs to be
469 	 * temporarily delayed for the Active/NonOptimized primary access state.
470 	 */
471 	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
472 	cmd->alua_nonop_delay = nonop_delay_msecs;
473 }
474 
475 static inline int core_alua_state_lba_dependent(
476 	struct se_cmd *cmd,
477 	struct t10_alua_tg_pt_gp *tg_pt_gp)
478 {
479 	struct se_device *dev = cmd->se_dev;
480 	u64 segment_size, segment_mult, sectors, lba;
481 
482 	/* Only need to check for cdb actually containing LBAs */
483 	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
484 		return 0;
485 
486 	spin_lock(&dev->t10_alua.lba_map_lock);
487 	segment_size = dev->t10_alua.lba_map_segment_size;
488 	segment_mult = dev->t10_alua.lba_map_segment_multiplier;
489 	sectors = cmd->data_length / dev->dev_attrib.block_size;
490 
491 	lba = cmd->t_task_lba;
492 	while (lba < cmd->t_task_lba + sectors) {
493 		struct t10_alua_lba_map *cur_map = NULL, *map;
494 		struct t10_alua_lba_map_member *map_mem;
495 
496 		list_for_each_entry(map, &dev->t10_alua.lba_map_list,
497 				    lba_map_list) {
498 			u64 start_lba, last_lba;
499 			u64 first_lba = map->lba_map_first_lba;
500 
501 			if (segment_mult) {
502 				u64 tmp = lba;
503 				start_lba = do_div(tmp, segment_size * segment_mult);
504 
505 				last_lba = first_lba + segment_size - 1;
506 				if (start_lba >= first_lba &&
507 				    start_lba <= last_lba) {
508 					lba += segment_size;
509 					cur_map = map;
510 					break;
511 				}
512 			} else {
513 				last_lba = map->lba_map_last_lba;
514 				if (lba >= first_lba && lba <= last_lba) {
515 					lba = last_lba + 1;
516 					cur_map = map;
517 					break;
518 				}
519 			}
520 		}
521 		if (!cur_map) {
522 			spin_unlock(&dev->t10_alua.lba_map_lock);
523 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
524 			return 1;
525 		}
526 		list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
527 				    lba_map_mem_list) {
528 			if (map_mem->lba_map_mem_alua_pg_id !=
529 			    tg_pt_gp->tg_pt_gp_id)
530 				continue;
531 			switch(map_mem->lba_map_mem_alua_state) {
532 			case ALUA_ACCESS_STATE_STANDBY:
533 				spin_unlock(&dev->t10_alua.lba_map_lock);
534 				set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
535 				return 1;
536 			case ALUA_ACCESS_STATE_UNAVAILABLE:
537 				spin_unlock(&dev->t10_alua.lba_map_lock);
538 				set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
539 				return 1;
540 			default:
541 				break;
542 			}
543 		}
544 	}
545 	spin_unlock(&dev->t10_alua.lba_map_lock);
546 	return 0;
547 }
548 
549 static inline int core_alua_state_standby(
550 	struct se_cmd *cmd,
551 	unsigned char *cdb)
552 {
553 	/*
554 	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
555 	 * spc4r17 section 5.9.2.4.4
556 	 */
557 	switch (cdb[0]) {
558 	case INQUIRY:
559 	case LOG_SELECT:
560 	case LOG_SENSE:
561 	case MODE_SELECT:
562 	case MODE_SENSE:
563 	case REPORT_LUNS:
564 	case RECEIVE_DIAGNOSTIC:
565 	case SEND_DIAGNOSTIC:
566 	case READ_CAPACITY:
567 		return 0;
568 	case SERVICE_ACTION_IN_16:
569 		switch (cdb[1] & 0x1f) {
570 		case SAI_READ_CAPACITY_16:
571 			return 0;
572 		default:
573 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
574 			return 1;
575 		}
576 	case MAINTENANCE_IN:
577 		switch (cdb[1] & 0x1f) {
578 		case MI_REPORT_TARGET_PGS:
579 			return 0;
580 		default:
581 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
582 			return 1;
583 		}
584 	case MAINTENANCE_OUT:
585 		switch (cdb[1]) {
586 		case MO_SET_TARGET_PGS:
587 			return 0;
588 		default:
589 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
590 			return 1;
591 		}
592 	case REQUEST_SENSE:
593 	case PERSISTENT_RESERVE_IN:
594 	case PERSISTENT_RESERVE_OUT:
595 	case READ_BUFFER:
596 	case WRITE_BUFFER:
597 		return 0;
598 	default:
599 		set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
600 		return 1;
601 	}
602 
603 	return 0;
604 }
605 
606 static inline int core_alua_state_unavailable(
607 	struct se_cmd *cmd,
608 	unsigned char *cdb)
609 {
610 	/*
611 	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
612 	 * spc4r17 section 5.9.2.4.5
613 	 */
614 	switch (cdb[0]) {
615 	case INQUIRY:
616 	case REPORT_LUNS:
617 		return 0;
618 	case MAINTENANCE_IN:
619 		switch (cdb[1] & 0x1f) {
620 		case MI_REPORT_TARGET_PGS:
621 			return 0;
622 		default:
623 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
624 			return 1;
625 		}
626 	case MAINTENANCE_OUT:
627 		switch (cdb[1]) {
628 		case MO_SET_TARGET_PGS:
629 			return 0;
630 		default:
631 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
632 			return 1;
633 		}
634 	case REQUEST_SENSE:
635 	case READ_BUFFER:
636 	case WRITE_BUFFER:
637 		return 0;
638 	default:
639 		set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
640 		return 1;
641 	}
642 
643 	return 0;
644 }
645 
646 static inline int core_alua_state_transition(
647 	struct se_cmd *cmd,
648 	unsigned char *cdb)
649 {
650 	/*
651 	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
652 	 * spc4r17 section 5.9.2.5
653 	 */
654 	switch (cdb[0]) {
655 	case INQUIRY:
656 	case REPORT_LUNS:
657 		return 0;
658 	case MAINTENANCE_IN:
659 		switch (cdb[1] & 0x1f) {
660 		case MI_REPORT_TARGET_PGS:
661 			return 0;
662 		default:
663 			set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
664 			return 1;
665 		}
666 	case REQUEST_SENSE:
667 	case READ_BUFFER:
668 	case WRITE_BUFFER:
669 		return 0;
670 	default:
671 		set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
672 		return 1;
673 	}
674 
675 	return 0;
676 }
677 
678 /*
679  * return 1: Is used to signal LUN not accessible, and check condition/not ready
680  * return 0: Used to signal success
681  * return -1: Used to signal failure, and invalid cdb field
682  */
683 sense_reason_t
684 target_alua_state_check(struct se_cmd *cmd)
685 {
686 	struct se_device *dev = cmd->se_dev;
687 	unsigned char *cdb = cmd->t_task_cdb;
688 	struct se_lun *lun = cmd->se_lun;
689 	struct t10_alua_tg_pt_gp *tg_pt_gp;
690 	int out_alua_state, nonop_delay_msecs;
691 
692 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
693 		return 0;
694 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
695 		return 0;
696 
697 	/*
698 	 * First, check for a struct se_port specific secondary ALUA target port
699 	 * access state: OFFLINE
700 	 */
701 	if (atomic_read(&lun->lun_tg_pt_secondary_offline)) {
702 		pr_debug("ALUA: Got secondary offline status for local"
703 				" target port\n");
704 		set_ascq(cmd, ASCQ_04H_ALUA_OFFLINE);
705 		return TCM_CHECK_CONDITION_NOT_READY;
706 	}
707 
708 	if (!lun->lun_tg_pt_gp)
709 		return 0;
710 
711 	spin_lock(&lun->lun_tg_pt_gp_lock);
712 	tg_pt_gp = lun->lun_tg_pt_gp;
713 	out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
714 	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
715 
716 	// XXX: keeps using tg_pt_gp witout reference after unlock
717 	spin_unlock(&lun->lun_tg_pt_gp_lock);
718 	/*
719 	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
720 	 * statement so the compiler knows explicitly to check this case first.
721 	 * For the Optimized ALUA access state case, we want to process the
722 	 * incoming fabric cmd ASAP..
723 	 */
724 	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
725 		return 0;
726 
727 	switch (out_alua_state) {
728 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
729 		core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
730 		break;
731 	case ALUA_ACCESS_STATE_STANDBY:
732 		if (core_alua_state_standby(cmd, cdb))
733 			return TCM_CHECK_CONDITION_NOT_READY;
734 		break;
735 	case ALUA_ACCESS_STATE_UNAVAILABLE:
736 		if (core_alua_state_unavailable(cmd, cdb))
737 			return TCM_CHECK_CONDITION_NOT_READY;
738 		break;
739 	case ALUA_ACCESS_STATE_TRANSITION:
740 		if (core_alua_state_transition(cmd, cdb))
741 			return TCM_CHECK_CONDITION_NOT_READY;
742 		break;
743 	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
744 		if (core_alua_state_lba_dependent(cmd, tg_pt_gp))
745 			return TCM_CHECK_CONDITION_NOT_READY;
746 		break;
747 	/*
748 	 * OFFLINE is a secondary ALUA target port group access state, that is
749 	 * handled above with struct se_lun->lun_tg_pt_secondary_offline=1
750 	 */
751 	case ALUA_ACCESS_STATE_OFFLINE:
752 	default:
753 		pr_err("Unknown ALUA access state: 0x%02x\n",
754 				out_alua_state);
755 		return TCM_INVALID_CDB_FIELD;
756 	}
757 
758 	return 0;
759 }
760 
761 /*
762  * Check implicit and explicit ALUA state change request.
763  */
764 static sense_reason_t
765 core_alua_check_transition(int state, int valid, int *primary, int explicit)
766 {
767 	/*
768 	 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
769 	 * defined as primary target port asymmetric access states.
770 	 */
771 	switch (state) {
772 	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
773 		if (!(valid & ALUA_AO_SUP))
774 			goto not_supported;
775 		*primary = 1;
776 		break;
777 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
778 		if (!(valid & ALUA_AN_SUP))
779 			goto not_supported;
780 		*primary = 1;
781 		break;
782 	case ALUA_ACCESS_STATE_STANDBY:
783 		if (!(valid & ALUA_S_SUP))
784 			goto not_supported;
785 		*primary = 1;
786 		break;
787 	case ALUA_ACCESS_STATE_UNAVAILABLE:
788 		if (!(valid & ALUA_U_SUP))
789 			goto not_supported;
790 		*primary = 1;
791 		break;
792 	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
793 		if (!(valid & ALUA_LBD_SUP))
794 			goto not_supported;
795 		*primary = 1;
796 		break;
797 	case ALUA_ACCESS_STATE_OFFLINE:
798 		/*
799 		 * OFFLINE state is defined as a secondary target port
800 		 * asymmetric access state.
801 		 */
802 		if (!(valid & ALUA_O_SUP))
803 			goto not_supported;
804 		*primary = 0;
805 		break;
806 	case ALUA_ACCESS_STATE_TRANSITION:
807 		if (!(valid & ALUA_T_SUP) || explicit)
808 			/*
809 			 * Transitioning is set internally and by tcmu daemon,
810 			 * and cannot be selected through a STPG.
811 			 */
812 			goto not_supported;
813 		*primary = 0;
814 		break;
815 	default:
816 		pr_err("Unknown ALUA access state: 0x%02x\n", state);
817 		return TCM_INVALID_PARAMETER_LIST;
818 	}
819 
820 	return 0;
821 
822 not_supported:
823 	pr_err("ALUA access state %s not supported",
824 	       core_alua_dump_state(state));
825 	return TCM_INVALID_PARAMETER_LIST;
826 }
827 
828 static char *core_alua_dump_state(int state)
829 {
830 	switch (state) {
831 	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
832 		return "Active/Optimized";
833 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
834 		return "Active/NonOptimized";
835 	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
836 		return "LBA Dependent";
837 	case ALUA_ACCESS_STATE_STANDBY:
838 		return "Standby";
839 	case ALUA_ACCESS_STATE_UNAVAILABLE:
840 		return "Unavailable";
841 	case ALUA_ACCESS_STATE_OFFLINE:
842 		return "Offline";
843 	case ALUA_ACCESS_STATE_TRANSITION:
844 		return "Transitioning";
845 	default:
846 		return "Unknown";
847 	}
848 
849 	return NULL;
850 }
851 
852 char *core_alua_dump_status(int status)
853 {
854 	switch (status) {
855 	case ALUA_STATUS_NONE:
856 		return "None";
857 	case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
858 		return "Altered by Explicit STPG";
859 	case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
860 		return "Altered by Implicit ALUA";
861 	default:
862 		return "Unknown";
863 	}
864 
865 	return NULL;
866 }
867 
868 /*
869  * Used by fabric modules to determine when we need to delay processing
870  * for the Active/NonOptimized paths..
871  */
872 int core_alua_check_nonop_delay(
873 	struct se_cmd *cmd)
874 {
875 	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
876 		return 0;
877 	if (in_interrupt())
878 		return 0;
879 	/*
880 	 * The ALUA Active/NonOptimized access state delay can be disabled
881 	 * in via configfs with a value of zero
882 	 */
883 	if (!cmd->alua_nonop_delay)
884 		return 0;
885 	/*
886 	 * struct se_cmd->alua_nonop_delay gets set by a target port group
887 	 * defined interval in core_alua_state_nonoptimized()
888 	 */
889 	msleep_interruptible(cmd->alua_nonop_delay);
890 	return 0;
891 }
892 EXPORT_SYMBOL(core_alua_check_nonop_delay);
893 
894 static int core_alua_write_tpg_metadata(
895 	const char *path,
896 	unsigned char *md_buf,
897 	u32 md_buf_len)
898 {
899 	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
900 	int ret;
901 
902 	if (IS_ERR(file)) {
903 		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
904 		return -ENODEV;
905 	}
906 	ret = kernel_write(file, md_buf, md_buf_len, 0);
907 	if (ret < 0)
908 		pr_err("Error writing ALUA metadata file: %s\n", path);
909 	fput(file);
910 	return (ret < 0) ? -EIO : 0;
911 }
912 
913 /*
914  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
915  */
916 static int core_alua_update_tpg_primary_metadata(
917 	struct t10_alua_tg_pt_gp *tg_pt_gp)
918 {
919 	unsigned char *md_buf;
920 	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
921 	char path[ALUA_METADATA_PATH_LEN];
922 	int len, rc;
923 
924 	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
925 	if (!md_buf) {
926 		pr_err("Unable to allocate buf for ALUA metadata\n");
927 		return -ENOMEM;
928 	}
929 
930 	memset(path, 0, ALUA_METADATA_PATH_LEN);
931 
932 	len = snprintf(md_buf, ALUA_MD_BUF_LEN,
933 			"tg_pt_gp_id=%hu\n"
934 			"alua_access_state=0x%02x\n"
935 			"alua_access_status=0x%02x\n",
936 			tg_pt_gp->tg_pt_gp_id,
937 			tg_pt_gp->tg_pt_gp_alua_pending_state,
938 			tg_pt_gp->tg_pt_gp_alua_access_status);
939 
940 	snprintf(path, ALUA_METADATA_PATH_LEN,
941 		"%s/alua/tpgs_%s/%s", db_root, &wwn->unit_serial[0],
942 		config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
943 
944 	rc = core_alua_write_tpg_metadata(path, md_buf, len);
945 	kfree(md_buf);
946 	return rc;
947 }
948 
949 static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
950 {
951 	struct se_dev_entry *se_deve;
952 	struct se_lun *lun;
953 	struct se_lun_acl *lacl;
954 
955 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
956 	list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
957 				lun_tg_pt_gp_link) {
958 		/*
959 		 * After an implicit target port asymmetric access state
960 		 * change, a device server shall establish a unit attention
961 		 * condition for the initiator port associated with every I_T
962 		 * nexus with the additional sense code set to ASYMMETRIC
963 		 * ACCESS STATE CHANGED.
964 		 *
965 		 * After an explicit target port asymmetric access state
966 		 * change, a device server shall establish a unit attention
967 		 * condition with the additional sense code set to ASYMMETRIC
968 		 * ACCESS STATE CHANGED for the initiator port associated with
969 		 * every I_T nexus other than the I_T nexus on which the SET
970 		 * TARGET PORT GROUPS command
971 		 */
972 		if (!percpu_ref_tryget_live(&lun->lun_ref))
973 			continue;
974 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
975 
976 		spin_lock(&lun->lun_deve_lock);
977 		list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
978 			lacl = rcu_dereference_check(se_deve->se_lun_acl,
979 					lockdep_is_held(&lun->lun_deve_lock));
980 
981 			/*
982 			 * spc4r37 p.242:
983 			 * After an explicit target port asymmetric access
984 			 * state change, a device server shall establish a
985 			 * unit attention condition with the additional sense
986 			 * code set to ASYMMETRIC ACCESS STATE CHANGED for
987 			 * the initiator port associated with every I_T nexus
988 			 * other than the I_T nexus on which the SET TARGET
989 			 * PORT GROUPS command was received.
990 			 */
991 			if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
992 			     ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
993 			   (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
994 			    (tg_pt_gp->tg_pt_gp_alua_lun == lun))
995 				continue;
996 
997 			/*
998 			 * se_deve->se_lun_acl pointer may be NULL for a
999 			 * entry created without explicit Node+MappedLUN ACLs
1000 			 */
1001 			if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
1002 			    (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
1003 				continue;
1004 
1005 			core_scsi3_ua_allocate(se_deve, 0x2A,
1006 				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
1007 		}
1008 		spin_unlock(&lun->lun_deve_lock);
1009 
1010 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1011 		percpu_ref_put(&lun->lun_ref);
1012 	}
1013 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1014 }
1015 
1016 static void core_alua_do_transition_tg_pt_work(struct work_struct *work)
1017 {
1018 	struct t10_alua_tg_pt_gp *tg_pt_gp = container_of(work,
1019 		struct t10_alua_tg_pt_gp, tg_pt_gp_transition_work);
1020 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1021 	bool explicit = (tg_pt_gp->tg_pt_gp_alua_access_status ==
1022 			 ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG);
1023 
1024 	/*
1025 	 * Update the ALUA metadata buf that has been allocated in
1026 	 * core_alua_do_port_transition(), this metadata will be written
1027 	 * to struct file.
1028 	 *
1029 	 * Note that there is the case where we do not want to update the
1030 	 * metadata when the saved metadata is being parsed in userspace
1031 	 * when setting the existing port access state and access status.
1032 	 *
1033 	 * Also note that the failure to write out the ALUA metadata to
1034 	 * struct file does NOT affect the actual ALUA transition.
1035 	 */
1036 	if (tg_pt_gp->tg_pt_gp_write_metadata) {
1037 		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
1038 		core_alua_update_tpg_primary_metadata(tg_pt_gp);
1039 		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
1040 	}
1041 	/*
1042 	 * Set the current primary ALUA access state to the requested new state
1043 	 */
1044 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1045 		   tg_pt_gp->tg_pt_gp_alua_pending_state);
1046 
1047 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1048 		" from primary access state %s to %s\n", (explicit) ? "explicit" :
1049 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1050 		tg_pt_gp->tg_pt_gp_id,
1051 		core_alua_dump_state(tg_pt_gp->tg_pt_gp_alua_previous_state),
1052 		core_alua_dump_state(tg_pt_gp->tg_pt_gp_alua_pending_state));
1053 
1054 	core_alua_queue_state_change_ua(tg_pt_gp);
1055 
1056 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1057 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1058 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1059 
1060 	if (tg_pt_gp->tg_pt_gp_transition_complete)
1061 		complete(tg_pt_gp->tg_pt_gp_transition_complete);
1062 }
1063 
1064 static int core_alua_do_transition_tg_pt(
1065 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1066 	int new_state,
1067 	int explicit)
1068 {
1069 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1070 	DECLARE_COMPLETION_ONSTACK(wait);
1071 
1072 	/* Nothing to be done here */
1073 	if (atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) == new_state)
1074 		return 0;
1075 
1076 	if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION)
1077 		return -EAGAIN;
1078 
1079 	/*
1080 	 * Flush any pending transitions
1081 	 */
1082 	if (!explicit)
1083 		flush_work(&tg_pt_gp->tg_pt_gp_transition_work);
1084 
1085 	/*
1086 	 * Save the old primary ALUA access state, and set the current state
1087 	 * to ALUA_ACCESS_STATE_TRANSITION.
1088 	 */
1089 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1090 			ALUA_ACCESS_STATE_TRANSITION);
1091 	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
1092 				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1093 				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1094 
1095 	core_alua_queue_state_change_ua(tg_pt_gp);
1096 
1097 	if (new_state == ALUA_ACCESS_STATE_TRANSITION)
1098 		return 0;
1099 
1100 	tg_pt_gp->tg_pt_gp_alua_previous_state =
1101 		atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
1102 	tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;
1103 
1104 	/*
1105 	 * Check for the optional ALUA primary state transition delay
1106 	 */
1107 	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
1108 		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1109 
1110 	/*
1111 	 * Take a reference for workqueue item
1112 	 */
1113 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1114 	atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1115 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1116 
1117 	schedule_work(&tg_pt_gp->tg_pt_gp_transition_work);
1118 	if (explicit) {
1119 		tg_pt_gp->tg_pt_gp_transition_complete = &wait;
1120 		wait_for_completion(&wait);
1121 		tg_pt_gp->tg_pt_gp_transition_complete = NULL;
1122 	}
1123 
1124 	return 0;
1125 }
1126 
1127 int core_alua_do_port_transition(
1128 	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
1129 	struct se_device *l_dev,
1130 	struct se_lun *l_lun,
1131 	struct se_node_acl *l_nacl,
1132 	int new_state,
1133 	int explicit)
1134 {
1135 	struct se_device *dev;
1136 	struct t10_alua_lu_gp *lu_gp;
1137 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
1138 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1139 	int primary, valid_states, rc = 0;
1140 
1141 	if (l_dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
1142 		return -ENODEV;
1143 
1144 	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
1145 	if (core_alua_check_transition(new_state, valid_states, &primary,
1146 				       explicit) != 0)
1147 		return -EINVAL;
1148 
1149 	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
1150 	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
1151 	lu_gp = local_lu_gp_mem->lu_gp;
1152 	atomic_inc(&lu_gp->lu_gp_ref_cnt);
1153 	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
1154 	/*
1155 	 * For storage objects that are members of the 'default_lu_gp',
1156 	 * we only do transition on the passed *l_tp_pt_gp, and not
1157 	 * on all of the matching target port groups IDs in default_lu_gp.
1158 	 */
1159 	if (!lu_gp->lu_gp_id) {
1160 		/*
1161 		 * core_alua_do_transition_tg_pt() will always return
1162 		 * success.
1163 		 */
1164 		l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1165 		l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1166 		rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
1167 						   new_state, explicit);
1168 		atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1169 		return rc;
1170 	}
1171 	/*
1172 	 * For all other LU groups aside from 'default_lu_gp', walk all of
1173 	 * the associated storage objects looking for a matching target port
1174 	 * group ID from the local target port group.
1175 	 */
1176 	spin_lock(&lu_gp->lu_gp_lock);
1177 	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
1178 				lu_gp_mem_list) {
1179 
1180 		dev = lu_gp_mem->lu_gp_mem_dev;
1181 		atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1182 		spin_unlock(&lu_gp->lu_gp_lock);
1183 
1184 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1185 		list_for_each_entry(tg_pt_gp,
1186 				&dev->t10_alua.tg_pt_gps_list,
1187 				tg_pt_gp_list) {
1188 
1189 			if (!tg_pt_gp->tg_pt_gp_valid_id)
1190 				continue;
1191 			/*
1192 			 * If the target behavior port asymmetric access state
1193 			 * is changed for any target port group accessible via
1194 			 * a logical unit within a LU group, the target port
1195 			 * behavior group asymmetric access states for the same
1196 			 * target port group accessible via other logical units
1197 			 * in that LU group will also change.
1198 			 */
1199 			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
1200 				continue;
1201 
1202 			if (l_tg_pt_gp == tg_pt_gp) {
1203 				tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1204 				tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1205 			} else {
1206 				tg_pt_gp->tg_pt_gp_alua_lun = NULL;
1207 				tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
1208 			}
1209 			atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1210 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1211 			/*
1212 			 * core_alua_do_transition_tg_pt() will always return
1213 			 * success.
1214 			 */
1215 			rc = core_alua_do_transition_tg_pt(tg_pt_gp,
1216 					new_state, explicit);
1217 
1218 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1219 			atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1220 			if (rc)
1221 				break;
1222 		}
1223 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1224 
1225 		spin_lock(&lu_gp->lu_gp_lock);
1226 		atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1227 	}
1228 	spin_unlock(&lu_gp->lu_gp_lock);
1229 
1230 	if (!rc) {
1231 		pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1232 			 " Group IDs: %hu %s transition to primary state: %s\n",
1233 			 config_item_name(&lu_gp->lu_gp_group.cg_item),
1234 			 l_tg_pt_gp->tg_pt_gp_id,
1235 			 (explicit) ? "explicit" : "implicit",
1236 			 core_alua_dump_state(new_state));
1237 	}
1238 
1239 	atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1240 	return rc;
1241 }
1242 
1243 static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
1244 {
1245 	struct se_portal_group *se_tpg = lun->lun_tpg;
1246 	unsigned char *md_buf;
1247 	char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1248 	int len, rc;
1249 
1250 	mutex_lock(&lun->lun_tg_pt_md_mutex);
1251 
1252 	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
1253 	if (!md_buf) {
1254 		pr_err("Unable to allocate buf for ALUA metadata\n");
1255 		rc = -ENOMEM;
1256 		goto out_unlock;
1257 	}
1258 
1259 	memset(path, 0, ALUA_METADATA_PATH_LEN);
1260 	memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1261 
1262 	len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1263 			se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1264 
1265 	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1266 		snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1267 				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1268 
1269 	len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
1270 			"alua_tg_pt_status=0x%02x\n",
1271 			atomic_read(&lun->lun_tg_pt_secondary_offline),
1272 			lun->lun_tg_pt_secondary_stat);
1273 
1274 	snprintf(path, ALUA_METADATA_PATH_LEN, "%s/alua/%s/%s/lun_%llu",
1275 			db_root, se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1276 			lun->unpacked_lun);
1277 
1278 	rc = core_alua_write_tpg_metadata(path, md_buf, len);
1279 	kfree(md_buf);
1280 
1281 out_unlock:
1282 	mutex_unlock(&lun->lun_tg_pt_md_mutex);
1283 	return rc;
1284 }
1285 
1286 static int core_alua_set_tg_pt_secondary_state(
1287 	struct se_lun *lun,
1288 	int explicit,
1289 	int offline)
1290 {
1291 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1292 	int trans_delay_msecs;
1293 
1294 	spin_lock(&lun->lun_tg_pt_gp_lock);
1295 	tg_pt_gp = lun->lun_tg_pt_gp;
1296 	if (!tg_pt_gp) {
1297 		spin_unlock(&lun->lun_tg_pt_gp_lock);
1298 		pr_err("Unable to complete secondary state"
1299 				" transition\n");
1300 		return -EINVAL;
1301 	}
1302 	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1303 	/*
1304 	 * Set the secondary ALUA target port access state to OFFLINE
1305 	 * or release the previously secondary state for struct se_lun
1306 	 */
1307 	if (offline)
1308 		atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
1309 	else
1310 		atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
1311 
1312 	lun->lun_tg_pt_secondary_stat = (explicit) ?
1313 			ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1314 			ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1315 
1316 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1317 		" to secondary access state: %s\n", (explicit) ? "explicit" :
1318 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1319 		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1320 
1321 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1322 	/*
1323 	 * Do the optional transition delay after we set the secondary
1324 	 * ALUA access state.
1325 	 */
1326 	if (trans_delay_msecs != 0)
1327 		msleep_interruptible(trans_delay_msecs);
1328 	/*
1329 	 * See if we need to update the ALUA fabric port metadata for
1330 	 * secondary state and status
1331 	 */
1332 	if (lun->lun_tg_pt_secondary_write_md)
1333 		core_alua_update_tpg_secondary_metadata(lun);
1334 
1335 	return 0;
1336 }
1337 
1338 struct t10_alua_lba_map *
1339 core_alua_allocate_lba_map(struct list_head *list,
1340 			   u64 first_lba, u64 last_lba)
1341 {
1342 	struct t10_alua_lba_map *lba_map;
1343 
1344 	lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
1345 	if (!lba_map) {
1346 		pr_err("Unable to allocate struct t10_alua_lba_map\n");
1347 		return ERR_PTR(-ENOMEM);
1348 	}
1349 	INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
1350 	lba_map->lba_map_first_lba = first_lba;
1351 	lba_map->lba_map_last_lba = last_lba;
1352 
1353 	list_add_tail(&lba_map->lba_map_list, list);
1354 	return lba_map;
1355 }
1356 
1357 int
1358 core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
1359 			       int pg_id, int state)
1360 {
1361 	struct t10_alua_lba_map_member *lba_map_mem;
1362 
1363 	list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
1364 			    lba_map_mem_list) {
1365 		if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
1366 			pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
1367 			return -EINVAL;
1368 		}
1369 	}
1370 
1371 	lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
1372 	if (!lba_map_mem) {
1373 		pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
1374 		return -ENOMEM;
1375 	}
1376 	lba_map_mem->lba_map_mem_alua_state = state;
1377 	lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
1378 
1379 	list_add_tail(&lba_map_mem->lba_map_mem_list,
1380 		      &lba_map->lba_map_mem_list);
1381 	return 0;
1382 }
1383 
1384 void
1385 core_alua_free_lba_map(struct list_head *lba_list)
1386 {
1387 	struct t10_alua_lba_map *lba_map, *lba_map_tmp;
1388 	struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
1389 
1390 	list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
1391 				 lba_map_list) {
1392 		list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
1393 					 &lba_map->lba_map_mem_list,
1394 					 lba_map_mem_list) {
1395 			list_del(&lba_map_mem->lba_map_mem_list);
1396 			kmem_cache_free(t10_alua_lba_map_mem_cache,
1397 					lba_map_mem);
1398 		}
1399 		list_del(&lba_map->lba_map_list);
1400 		kmem_cache_free(t10_alua_lba_map_cache, lba_map);
1401 	}
1402 }
1403 
1404 void
1405 core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
1406 		      int segment_size, int segment_mult)
1407 {
1408 	struct list_head old_lba_map_list;
1409 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1410 	int activate = 0, supported;
1411 
1412 	INIT_LIST_HEAD(&old_lba_map_list);
1413 	spin_lock(&dev->t10_alua.lba_map_lock);
1414 	dev->t10_alua.lba_map_segment_size = segment_size;
1415 	dev->t10_alua.lba_map_segment_multiplier = segment_mult;
1416 	list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
1417 	if (lba_map_list) {
1418 		list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
1419 		activate = 1;
1420 	}
1421 	spin_unlock(&dev->t10_alua.lba_map_lock);
1422 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1423 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1424 			    tg_pt_gp_list) {
1425 
1426 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1427 			continue;
1428 		supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
1429 		if (activate)
1430 			supported |= ALUA_LBD_SUP;
1431 		else
1432 			supported &= ~ALUA_LBD_SUP;
1433 		tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
1434 	}
1435 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1436 	core_alua_free_lba_map(&old_lba_map_list);
1437 }
1438 
1439 struct t10_alua_lu_gp *
1440 core_alua_allocate_lu_gp(const char *name, int def_group)
1441 {
1442 	struct t10_alua_lu_gp *lu_gp;
1443 
1444 	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1445 	if (!lu_gp) {
1446 		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1447 		return ERR_PTR(-ENOMEM);
1448 	}
1449 	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1450 	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1451 	spin_lock_init(&lu_gp->lu_gp_lock);
1452 	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1453 
1454 	if (def_group) {
1455 		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1456 		lu_gp->lu_gp_valid_id = 1;
1457 		alua_lu_gps_count++;
1458 	}
1459 
1460 	return lu_gp;
1461 }
1462 
1463 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1464 {
1465 	struct t10_alua_lu_gp *lu_gp_tmp;
1466 	u16 lu_gp_id_tmp;
1467 	/*
1468 	 * The lu_gp->lu_gp_id may only be set once..
1469 	 */
1470 	if (lu_gp->lu_gp_valid_id) {
1471 		pr_warn("ALUA LU Group already has a valid ID,"
1472 			" ignoring request\n");
1473 		return -EINVAL;
1474 	}
1475 
1476 	spin_lock(&lu_gps_lock);
1477 	if (alua_lu_gps_count == 0x0000ffff) {
1478 		pr_err("Maximum ALUA alua_lu_gps_count:"
1479 				" 0x0000ffff reached\n");
1480 		spin_unlock(&lu_gps_lock);
1481 		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1482 		return -ENOSPC;
1483 	}
1484 again:
1485 	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1486 				alua_lu_gps_counter++;
1487 
1488 	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1489 		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1490 			if (!lu_gp_id)
1491 				goto again;
1492 
1493 			pr_warn("ALUA Logical Unit Group ID: %hu"
1494 				" already exists, ignoring request\n",
1495 				lu_gp_id);
1496 			spin_unlock(&lu_gps_lock);
1497 			return -EINVAL;
1498 		}
1499 	}
1500 
1501 	lu_gp->lu_gp_id = lu_gp_id_tmp;
1502 	lu_gp->lu_gp_valid_id = 1;
1503 	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1504 	alua_lu_gps_count++;
1505 	spin_unlock(&lu_gps_lock);
1506 
1507 	return 0;
1508 }
1509 
1510 static struct t10_alua_lu_gp_member *
1511 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1512 {
1513 	struct t10_alua_lu_gp_member *lu_gp_mem;
1514 
1515 	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1516 	if (!lu_gp_mem) {
1517 		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1518 		return ERR_PTR(-ENOMEM);
1519 	}
1520 	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1521 	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1522 	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1523 
1524 	lu_gp_mem->lu_gp_mem_dev = dev;
1525 	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1526 
1527 	return lu_gp_mem;
1528 }
1529 
1530 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1531 {
1532 	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1533 	/*
1534 	 * Once we have reached this point, config_item_put() has
1535 	 * already been called from target_core_alua_drop_lu_gp().
1536 	 *
1537 	 * Here, we remove the *lu_gp from the global list so that
1538 	 * no associations can be made while we are releasing
1539 	 * struct t10_alua_lu_gp.
1540 	 */
1541 	spin_lock(&lu_gps_lock);
1542 	list_del(&lu_gp->lu_gp_node);
1543 	alua_lu_gps_count--;
1544 	spin_unlock(&lu_gps_lock);
1545 	/*
1546 	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1547 	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1548 	 * released with core_alua_put_lu_gp_from_name()
1549 	 */
1550 	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1551 		cpu_relax();
1552 	/*
1553 	 * Release reference to struct t10_alua_lu_gp * from all associated
1554 	 * struct se_device.
1555 	 */
1556 	spin_lock(&lu_gp->lu_gp_lock);
1557 	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1558 				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1559 		if (lu_gp_mem->lu_gp_assoc) {
1560 			list_del(&lu_gp_mem->lu_gp_mem_list);
1561 			lu_gp->lu_gp_members--;
1562 			lu_gp_mem->lu_gp_assoc = 0;
1563 		}
1564 		spin_unlock(&lu_gp->lu_gp_lock);
1565 		/*
1566 		 *
1567 		 * lu_gp_mem is associated with a single
1568 		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1569 		 * struct se_device is released via core_alua_free_lu_gp_mem().
1570 		 *
1571 		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1572 		 * we want to re-associate a given lu_gp_mem with default_lu_gp.
1573 		 */
1574 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1575 		if (lu_gp != default_lu_gp)
1576 			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1577 					default_lu_gp);
1578 		else
1579 			lu_gp_mem->lu_gp = NULL;
1580 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1581 
1582 		spin_lock(&lu_gp->lu_gp_lock);
1583 	}
1584 	spin_unlock(&lu_gp->lu_gp_lock);
1585 
1586 	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1587 }
1588 
1589 void core_alua_free_lu_gp_mem(struct se_device *dev)
1590 {
1591 	struct t10_alua_lu_gp *lu_gp;
1592 	struct t10_alua_lu_gp_member *lu_gp_mem;
1593 
1594 	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1595 	if (!lu_gp_mem)
1596 		return;
1597 
1598 	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1599 		cpu_relax();
1600 
1601 	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1602 	lu_gp = lu_gp_mem->lu_gp;
1603 	if (lu_gp) {
1604 		spin_lock(&lu_gp->lu_gp_lock);
1605 		if (lu_gp_mem->lu_gp_assoc) {
1606 			list_del(&lu_gp_mem->lu_gp_mem_list);
1607 			lu_gp->lu_gp_members--;
1608 			lu_gp_mem->lu_gp_assoc = 0;
1609 		}
1610 		spin_unlock(&lu_gp->lu_gp_lock);
1611 		lu_gp_mem->lu_gp = NULL;
1612 	}
1613 	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1614 
1615 	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1616 }
1617 
1618 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1619 {
1620 	struct t10_alua_lu_gp *lu_gp;
1621 	struct config_item *ci;
1622 
1623 	spin_lock(&lu_gps_lock);
1624 	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1625 		if (!lu_gp->lu_gp_valid_id)
1626 			continue;
1627 		ci = &lu_gp->lu_gp_group.cg_item;
1628 		if (!strcmp(config_item_name(ci), name)) {
1629 			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1630 			spin_unlock(&lu_gps_lock);
1631 			return lu_gp;
1632 		}
1633 	}
1634 	spin_unlock(&lu_gps_lock);
1635 
1636 	return NULL;
1637 }
1638 
1639 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1640 {
1641 	spin_lock(&lu_gps_lock);
1642 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1643 	spin_unlock(&lu_gps_lock);
1644 }
1645 
1646 /*
1647  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1648  */
1649 void __core_alua_attach_lu_gp_mem(
1650 	struct t10_alua_lu_gp_member *lu_gp_mem,
1651 	struct t10_alua_lu_gp *lu_gp)
1652 {
1653 	spin_lock(&lu_gp->lu_gp_lock);
1654 	lu_gp_mem->lu_gp = lu_gp;
1655 	lu_gp_mem->lu_gp_assoc = 1;
1656 	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1657 	lu_gp->lu_gp_members++;
1658 	spin_unlock(&lu_gp->lu_gp_lock);
1659 }
1660 
1661 /*
1662  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1663  */
1664 void __core_alua_drop_lu_gp_mem(
1665 	struct t10_alua_lu_gp_member *lu_gp_mem,
1666 	struct t10_alua_lu_gp *lu_gp)
1667 {
1668 	spin_lock(&lu_gp->lu_gp_lock);
1669 	list_del(&lu_gp_mem->lu_gp_mem_list);
1670 	lu_gp_mem->lu_gp = NULL;
1671 	lu_gp_mem->lu_gp_assoc = 0;
1672 	lu_gp->lu_gp_members--;
1673 	spin_unlock(&lu_gp->lu_gp_lock);
1674 }
1675 
1676 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1677 		const char *name, int def_group)
1678 {
1679 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1680 
1681 	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1682 	if (!tg_pt_gp) {
1683 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1684 		return NULL;
1685 	}
1686 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1687 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
1688 	mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1689 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1690 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1691 	INIT_WORK(&tg_pt_gp->tg_pt_gp_transition_work,
1692 		  core_alua_do_transition_tg_pt_work);
1693 	tg_pt_gp->tg_pt_gp_dev = dev;
1694 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1695 		ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED);
1696 	/*
1697 	 * Enable both explicit and implicit ALUA support by default
1698 	 */
1699 	tg_pt_gp->tg_pt_gp_alua_access_type =
1700 			TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1701 	/*
1702 	 * Set the default Active/NonOptimized Delay in milliseconds
1703 	 */
1704 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1705 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1706 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1707 
1708 	/*
1709 	 * Enable all supported states
1710 	 */
1711 	tg_pt_gp->tg_pt_gp_alua_supported_states =
1712 	    ALUA_T_SUP | ALUA_O_SUP |
1713 	    ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1714 
1715 	if (def_group) {
1716 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1717 		tg_pt_gp->tg_pt_gp_id =
1718 				dev->t10_alua.alua_tg_pt_gps_counter++;
1719 		tg_pt_gp->tg_pt_gp_valid_id = 1;
1720 		dev->t10_alua.alua_tg_pt_gps_count++;
1721 		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1722 			      &dev->t10_alua.tg_pt_gps_list);
1723 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1724 	}
1725 
1726 	return tg_pt_gp;
1727 }
1728 
1729 int core_alua_set_tg_pt_gp_id(
1730 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1731 	u16 tg_pt_gp_id)
1732 {
1733 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1734 	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1735 	u16 tg_pt_gp_id_tmp;
1736 
1737 	/*
1738 	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1739 	 */
1740 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1741 		pr_warn("ALUA TG PT Group already has a valid ID,"
1742 			" ignoring request\n");
1743 		return -EINVAL;
1744 	}
1745 
1746 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1747 	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1748 		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1749 			" 0x0000ffff reached\n");
1750 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1751 		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1752 		return -ENOSPC;
1753 	}
1754 again:
1755 	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1756 			dev->t10_alua.alua_tg_pt_gps_counter++;
1757 
1758 	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1759 			tg_pt_gp_list) {
1760 		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1761 			if (!tg_pt_gp_id)
1762 				goto again;
1763 
1764 			pr_err("ALUA Target Port Group ID: %hu already"
1765 				" exists, ignoring request\n", tg_pt_gp_id);
1766 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1767 			return -EINVAL;
1768 		}
1769 	}
1770 
1771 	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1772 	tg_pt_gp->tg_pt_gp_valid_id = 1;
1773 	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1774 			&dev->t10_alua.tg_pt_gps_list);
1775 	dev->t10_alua.alua_tg_pt_gps_count++;
1776 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1777 
1778 	return 0;
1779 }
1780 
1781 void core_alua_free_tg_pt_gp(
1782 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1783 {
1784 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1785 	struct se_lun *lun, *next;
1786 
1787 	/*
1788 	 * Once we have reached this point, config_item_put() has already
1789 	 * been called from target_core_alua_drop_tg_pt_gp().
1790 	 *
1791 	 * Here we remove *tg_pt_gp from the global list so that
1792 	 * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1793 	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1794 	 */
1795 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1796 	list_del(&tg_pt_gp->tg_pt_gp_list);
1797 	dev->t10_alua.alua_tg_pt_gps_counter--;
1798 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1799 
1800 	flush_work(&tg_pt_gp->tg_pt_gp_transition_work);
1801 
1802 	/*
1803 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1804 	 * core_alua_get_tg_pt_gp_by_name() in
1805 	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1806 	 * to be released with core_alua_put_tg_pt_gp_from_name().
1807 	 */
1808 	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1809 		cpu_relax();
1810 
1811 	/*
1812 	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1813 	 * struct se_port.
1814 	 */
1815 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1816 	list_for_each_entry_safe(lun, next,
1817 			&tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
1818 		list_del_init(&lun->lun_tg_pt_gp_link);
1819 		tg_pt_gp->tg_pt_gp_members--;
1820 
1821 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1822 		/*
1823 		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1824 		 * assume we want to re-associate a given tg_pt_gp_mem with
1825 		 * default_tg_pt_gp.
1826 		 */
1827 		spin_lock(&lun->lun_tg_pt_gp_lock);
1828 		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1829 			__target_attach_tg_pt_gp(lun,
1830 					dev->t10_alua.default_tg_pt_gp);
1831 		} else
1832 			lun->lun_tg_pt_gp = NULL;
1833 		spin_unlock(&lun->lun_tg_pt_gp_lock);
1834 
1835 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1836 	}
1837 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1838 
1839 	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1840 }
1841 
1842 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1843 		struct se_device *dev, const char *name)
1844 {
1845 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1846 	struct config_item *ci;
1847 
1848 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1849 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1850 			tg_pt_gp_list) {
1851 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1852 			continue;
1853 		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1854 		if (!strcmp(config_item_name(ci), name)) {
1855 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1856 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1857 			return tg_pt_gp;
1858 		}
1859 	}
1860 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1861 
1862 	return NULL;
1863 }
1864 
1865 static void core_alua_put_tg_pt_gp_from_name(
1866 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1867 {
1868 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1869 
1870 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1871 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1872 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1873 }
1874 
1875 static void __target_attach_tg_pt_gp(struct se_lun *lun,
1876 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1877 {
1878 	struct se_dev_entry *se_deve;
1879 
1880 	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1881 
1882 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1883 	lun->lun_tg_pt_gp = tg_pt_gp;
1884 	list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
1885 	tg_pt_gp->tg_pt_gp_members++;
1886 	spin_lock(&lun->lun_deve_lock);
1887 	list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
1888 		core_scsi3_ua_allocate(se_deve, 0x3f,
1889 				       ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
1890 	spin_unlock(&lun->lun_deve_lock);
1891 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1892 }
1893 
1894 void target_attach_tg_pt_gp(struct se_lun *lun,
1895 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1896 {
1897 	spin_lock(&lun->lun_tg_pt_gp_lock);
1898 	__target_attach_tg_pt_gp(lun, tg_pt_gp);
1899 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1900 }
1901 
1902 static void __target_detach_tg_pt_gp(struct se_lun *lun,
1903 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1904 {
1905 	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1906 
1907 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1908 	list_del_init(&lun->lun_tg_pt_gp_link);
1909 	tg_pt_gp->tg_pt_gp_members--;
1910 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1911 
1912 	lun->lun_tg_pt_gp = NULL;
1913 }
1914 
1915 void target_detach_tg_pt_gp(struct se_lun *lun)
1916 {
1917 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1918 
1919 	spin_lock(&lun->lun_tg_pt_gp_lock);
1920 	tg_pt_gp = lun->lun_tg_pt_gp;
1921 	if (tg_pt_gp)
1922 		__target_detach_tg_pt_gp(lun, tg_pt_gp);
1923 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1924 }
1925 
1926 ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
1927 {
1928 	struct config_item *tg_pt_ci;
1929 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1930 	ssize_t len = 0;
1931 
1932 	spin_lock(&lun->lun_tg_pt_gp_lock);
1933 	tg_pt_gp = lun->lun_tg_pt_gp;
1934 	if (tg_pt_gp) {
1935 		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1936 		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1937 			" %hu\nTG Port Primary Access State: %s\nTG Port "
1938 			"Primary Access Status: %s\nTG Port Secondary Access"
1939 			" State: %s\nTG Port Secondary Access Status: %s\n",
1940 			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1941 			core_alua_dump_state(atomic_read(
1942 					&tg_pt_gp->tg_pt_gp_alua_access_state)),
1943 			core_alua_dump_status(
1944 				tg_pt_gp->tg_pt_gp_alua_access_status),
1945 			atomic_read(&lun->lun_tg_pt_secondary_offline) ?
1946 			"Offline" : "None",
1947 			core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
1948 	}
1949 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1950 
1951 	return len;
1952 }
1953 
1954 ssize_t core_alua_store_tg_pt_gp_info(
1955 	struct se_lun *lun,
1956 	const char *page,
1957 	size_t count)
1958 {
1959 	struct se_portal_group *tpg = lun->lun_tpg;
1960 	/*
1961 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
1962 	 * reference to se_device->dev_group.
1963 	 */
1964 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
1965 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1966 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1967 	int move = 0;
1968 
1969 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
1970 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
1971 		return -ENODEV;
1972 
1973 	if (count > TG_PT_GROUP_NAME_BUF) {
1974 		pr_err("ALUA Target Port Group alias too large!\n");
1975 		return -EINVAL;
1976 	}
1977 	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1978 	memcpy(buf, page, count);
1979 	/*
1980 	 * Any ALUA target port group alias besides "NULL" means we will be
1981 	 * making a new group association.
1982 	 */
1983 	if (strcmp(strstrip(buf), "NULL")) {
1984 		/*
1985 		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1986 		 * struct t10_alua_tg_pt_gp.  This reference is released with
1987 		 * core_alua_put_tg_pt_gp_from_name() below.
1988 		 */
1989 		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1990 					strstrip(buf));
1991 		if (!tg_pt_gp_new)
1992 			return -ENODEV;
1993 	}
1994 
1995 	spin_lock(&lun->lun_tg_pt_gp_lock);
1996 	tg_pt_gp = lun->lun_tg_pt_gp;
1997 	if (tg_pt_gp) {
1998 		/*
1999 		 * Clearing an existing tg_pt_gp association, and replacing
2000 		 * with the default_tg_pt_gp.
2001 		 */
2002 		if (!tg_pt_gp_new) {
2003 			pr_debug("Target_Core_ConfigFS: Moving"
2004 				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
2005 				" alua/%s, ID: %hu back to"
2006 				" default_tg_pt_gp\n",
2007 				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
2008 				tpg->se_tpg_tfo->tpg_get_tag(tpg),
2009 				config_item_name(&lun->lun_group.cg_item),
2010 				config_item_name(
2011 					&tg_pt_gp->tg_pt_gp_group.cg_item),
2012 				tg_pt_gp->tg_pt_gp_id);
2013 
2014 			__target_detach_tg_pt_gp(lun, tg_pt_gp);
2015 			__target_attach_tg_pt_gp(lun,
2016 					dev->t10_alua.default_tg_pt_gp);
2017 			spin_unlock(&lun->lun_tg_pt_gp_lock);
2018 
2019 			return count;
2020 		}
2021 		__target_detach_tg_pt_gp(lun, tg_pt_gp);
2022 		move = 1;
2023 	}
2024 
2025 	__target_attach_tg_pt_gp(lun, tg_pt_gp_new);
2026 	spin_unlock(&lun->lun_tg_pt_gp_lock);
2027 	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
2028 		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
2029 		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
2030 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
2031 		config_item_name(&lun->lun_group.cg_item),
2032 		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
2033 		tg_pt_gp_new->tg_pt_gp_id);
2034 
2035 	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
2036 	return count;
2037 }
2038 
2039 ssize_t core_alua_show_access_type(
2040 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2041 	char *page)
2042 {
2043 	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
2044 	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
2045 		return sprintf(page, "Implicit and Explicit\n");
2046 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
2047 		return sprintf(page, "Implicit\n");
2048 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
2049 		return sprintf(page, "Explicit\n");
2050 	else
2051 		return sprintf(page, "None\n");
2052 }
2053 
2054 ssize_t core_alua_store_access_type(
2055 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2056 	const char *page,
2057 	size_t count)
2058 {
2059 	unsigned long tmp;
2060 	int ret;
2061 
2062 	ret = kstrtoul(page, 0, &tmp);
2063 	if (ret < 0) {
2064 		pr_err("Unable to extract alua_access_type\n");
2065 		return ret;
2066 	}
2067 	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
2068 		pr_err("Illegal value for alua_access_type:"
2069 				" %lu\n", tmp);
2070 		return -EINVAL;
2071 	}
2072 	if (tmp == 3)
2073 		tg_pt_gp->tg_pt_gp_alua_access_type =
2074 			TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
2075 	else if (tmp == 2)
2076 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
2077 	else if (tmp == 1)
2078 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
2079 	else
2080 		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
2081 
2082 	return count;
2083 }
2084 
2085 ssize_t core_alua_show_nonop_delay_msecs(
2086 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2087 	char *page)
2088 {
2089 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
2090 }
2091 
2092 ssize_t core_alua_store_nonop_delay_msecs(
2093 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2094 	const char *page,
2095 	size_t count)
2096 {
2097 	unsigned long tmp;
2098 	int ret;
2099 
2100 	ret = kstrtoul(page, 0, &tmp);
2101 	if (ret < 0) {
2102 		pr_err("Unable to extract nonop_delay_msecs\n");
2103 		return ret;
2104 	}
2105 	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
2106 		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
2107 			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
2108 			ALUA_MAX_NONOP_DELAY_MSECS);
2109 		return -EINVAL;
2110 	}
2111 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
2112 
2113 	return count;
2114 }
2115 
2116 ssize_t core_alua_show_trans_delay_msecs(
2117 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2118 	char *page)
2119 {
2120 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
2121 }
2122 
2123 ssize_t core_alua_store_trans_delay_msecs(
2124 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2125 	const char *page,
2126 	size_t count)
2127 {
2128 	unsigned long tmp;
2129 	int ret;
2130 
2131 	ret = kstrtoul(page, 0, &tmp);
2132 	if (ret < 0) {
2133 		pr_err("Unable to extract trans_delay_msecs\n");
2134 		return ret;
2135 	}
2136 	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
2137 		pr_err("Passed trans_delay_msecs: %lu, exceeds"
2138 			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
2139 			ALUA_MAX_TRANS_DELAY_MSECS);
2140 		return -EINVAL;
2141 	}
2142 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
2143 
2144 	return count;
2145 }
2146 
2147 ssize_t core_alua_show_implicit_trans_secs(
2148 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2149 	char *page)
2150 {
2151 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
2152 }
2153 
2154 ssize_t core_alua_store_implicit_trans_secs(
2155 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2156 	const char *page,
2157 	size_t count)
2158 {
2159 	unsigned long tmp;
2160 	int ret;
2161 
2162 	ret = kstrtoul(page, 0, &tmp);
2163 	if (ret < 0) {
2164 		pr_err("Unable to extract implicit_trans_secs\n");
2165 		return ret;
2166 	}
2167 	if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
2168 		pr_err("Passed implicit_trans_secs: %lu, exceeds"
2169 			" ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
2170 			ALUA_MAX_IMPLICIT_TRANS_SECS);
2171 		return  -EINVAL;
2172 	}
2173 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
2174 
2175 	return count;
2176 }
2177 
2178 ssize_t core_alua_show_preferred_bit(
2179 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2180 	char *page)
2181 {
2182 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
2183 }
2184 
2185 ssize_t core_alua_store_preferred_bit(
2186 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2187 	const char *page,
2188 	size_t count)
2189 {
2190 	unsigned long tmp;
2191 	int ret;
2192 
2193 	ret = kstrtoul(page, 0, &tmp);
2194 	if (ret < 0) {
2195 		pr_err("Unable to extract preferred ALUA value\n");
2196 		return ret;
2197 	}
2198 	if ((tmp != 0) && (tmp != 1)) {
2199 		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
2200 		return -EINVAL;
2201 	}
2202 	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
2203 
2204 	return count;
2205 }
2206 
2207 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
2208 {
2209 	return sprintf(page, "%d\n",
2210 		atomic_read(&lun->lun_tg_pt_secondary_offline));
2211 }
2212 
2213 ssize_t core_alua_store_offline_bit(
2214 	struct se_lun *lun,
2215 	const char *page,
2216 	size_t count)
2217 {
2218 	/*
2219 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
2220 	 * reference to se_device->dev_group.
2221 	 */
2222 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
2223 	unsigned long tmp;
2224 	int ret;
2225 
2226 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
2227 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
2228 		return -ENODEV;
2229 
2230 	ret = kstrtoul(page, 0, &tmp);
2231 	if (ret < 0) {
2232 		pr_err("Unable to extract alua_tg_pt_offline value\n");
2233 		return ret;
2234 	}
2235 	if ((tmp != 0) && (tmp != 1)) {
2236 		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
2237 				tmp);
2238 		return -EINVAL;
2239 	}
2240 
2241 	ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
2242 	if (ret < 0)
2243 		return -EINVAL;
2244 
2245 	return count;
2246 }
2247 
2248 ssize_t core_alua_show_secondary_status(
2249 	struct se_lun *lun,
2250 	char *page)
2251 {
2252 	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
2253 }
2254 
2255 ssize_t core_alua_store_secondary_status(
2256 	struct se_lun *lun,
2257 	const char *page,
2258 	size_t count)
2259 {
2260 	unsigned long tmp;
2261 	int ret;
2262 
2263 	ret = kstrtoul(page, 0, &tmp);
2264 	if (ret < 0) {
2265 		pr_err("Unable to extract alua_tg_pt_status\n");
2266 		return ret;
2267 	}
2268 	if ((tmp != ALUA_STATUS_NONE) &&
2269 	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
2270 	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
2271 		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2272 				tmp);
2273 		return -EINVAL;
2274 	}
2275 	lun->lun_tg_pt_secondary_stat = (int)tmp;
2276 
2277 	return count;
2278 }
2279 
2280 ssize_t core_alua_show_secondary_write_metadata(
2281 	struct se_lun *lun,
2282 	char *page)
2283 {
2284 	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
2285 }
2286 
2287 ssize_t core_alua_store_secondary_write_metadata(
2288 	struct se_lun *lun,
2289 	const char *page,
2290 	size_t count)
2291 {
2292 	unsigned long tmp;
2293 	int ret;
2294 
2295 	ret = kstrtoul(page, 0, &tmp);
2296 	if (ret < 0) {
2297 		pr_err("Unable to extract alua_tg_pt_write_md\n");
2298 		return ret;
2299 	}
2300 	if ((tmp != 0) && (tmp != 1)) {
2301 		pr_err("Illegal value for alua_tg_pt_write_md:"
2302 				" %lu\n", tmp);
2303 		return -EINVAL;
2304 	}
2305 	lun->lun_tg_pt_secondary_write_md = (int)tmp;
2306 
2307 	return count;
2308 }
2309 
2310 int core_setup_alua(struct se_device *dev)
2311 {
2312 	if (!(dev->transport->transport_flags &
2313 	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
2314 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2315 		struct t10_alua_lu_gp_member *lu_gp_mem;
2316 
2317 		/*
2318 		 * Associate this struct se_device with the default ALUA
2319 		 * LUN Group.
2320 		 */
2321 		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2322 		if (IS_ERR(lu_gp_mem))
2323 			return PTR_ERR(lu_gp_mem);
2324 
2325 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2326 		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2327 				default_lu_gp);
2328 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2329 
2330 		pr_debug("%s: Adding to default ALUA LU Group:"
2331 			" core/alua/lu_gps/default_lu_gp\n",
2332 			dev->transport->name);
2333 	}
2334 
2335 	return 0;
2336 }
2337