xref: /linux/drivers/target/target_core_alua.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename:  target_core_alua.c
4  *
5  * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
6  *
7  * (c) Copyright 2009-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  ******************************************************************************/
12 
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15 #include <linux/configfs.h>
16 #include <linux/delay.h>
17 #include <linux/export.h>
18 #include <linux/fcntl.h>
19 #include <linux/file.h>
20 #include <linux/fs.h>
21 #include <scsi/scsi_proto.h>
22 #include <asm/unaligned.h>
23 
24 #include <target/target_core_base.h>
25 #include <target/target_core_backend.h>
26 #include <target/target_core_fabric.h>
27 
28 #include "target_core_internal.h"
29 #include "target_core_alua.h"
30 #include "target_core_ua.h"
31 
32 static sense_reason_t core_alua_check_transition(int state, int valid,
33 						 int *primary, int explicit);
34 static int core_alua_set_tg_pt_secondary_state(
35 		struct se_lun *lun, int explicit, int offline);
36 
37 static char *core_alua_dump_state(int state);
38 
39 static void __target_attach_tg_pt_gp(struct se_lun *lun,
40 		struct t10_alua_tg_pt_gp *tg_pt_gp);
41 
42 static u16 alua_lu_gps_counter;
43 static u32 alua_lu_gps_count;
44 
45 static DEFINE_SPINLOCK(lu_gps_lock);
46 static LIST_HEAD(lu_gps_list);
47 
48 struct t10_alua_lu_gp *default_lu_gp;
49 
50 /*
51  * REPORT REFERRALS
52  *
53  * See sbc3r35 section 5.23
54  */
55 sense_reason_t
56 target_emulate_report_referrals(struct se_cmd *cmd)
57 {
58 	struct se_device *dev = cmd->se_dev;
59 	struct t10_alua_lba_map *map;
60 	struct t10_alua_lba_map_member *map_mem;
61 	unsigned char *buf;
62 	u32 rd_len = 0, off;
63 
64 	if (cmd->data_length < 4) {
65 		pr_warn("REPORT REFERRALS allocation length %u too"
66 			" small\n", cmd->data_length);
67 		return TCM_INVALID_CDB_FIELD;
68 	}
69 
70 	buf = transport_kmap_data_sg(cmd);
71 	if (!buf)
72 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
73 
74 	off = 4;
75 	spin_lock(&dev->t10_alua.lba_map_lock);
76 	if (list_empty(&dev->t10_alua.lba_map_list)) {
77 		spin_unlock(&dev->t10_alua.lba_map_lock);
78 		transport_kunmap_data_sg(cmd);
79 
80 		return TCM_UNSUPPORTED_SCSI_OPCODE;
81 	}
82 
83 	list_for_each_entry(map, &dev->t10_alua.lba_map_list,
84 			    lba_map_list) {
85 		int desc_num = off + 3;
86 		int pg_num;
87 
88 		off += 4;
89 		if (cmd->data_length > off)
90 			put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
91 		off += 8;
92 		if (cmd->data_length > off)
93 			put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
94 		off += 8;
95 		rd_len += 20;
96 		pg_num = 0;
97 		list_for_each_entry(map_mem, &map->lba_map_mem_list,
98 				    lba_map_mem_list) {
99 			int alua_state = map_mem->lba_map_mem_alua_state;
100 			int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;
101 
102 			if (cmd->data_length > off)
103 				buf[off] = alua_state & 0x0f;
104 			off += 2;
105 			if (cmd->data_length > off)
106 				buf[off] = (alua_pg_id >> 8) & 0xff;
107 			off++;
108 			if (cmd->data_length > off)
109 				buf[off] = (alua_pg_id & 0xff);
110 			off++;
111 			rd_len += 4;
112 			pg_num++;
113 		}
114 		if (cmd->data_length > desc_num)
115 			buf[desc_num] = pg_num;
116 	}
117 	spin_unlock(&dev->t10_alua.lba_map_lock);
118 
119 	/*
120 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
121 	 */
122 	put_unaligned_be16(rd_len, &buf[2]);
123 
124 	transport_kunmap_data_sg(cmd);
125 
126 	target_complete_cmd(cmd, SAM_STAT_GOOD);
127 	return 0;
128 }
129 
130 /*
131  * REPORT_TARGET_PORT_GROUPS
132  *
133  * See spc4r17 section 6.27
134  */
135 sense_reason_t
136 target_emulate_report_target_port_groups(struct se_cmd *cmd)
137 {
138 	struct se_device *dev = cmd->se_dev;
139 	struct t10_alua_tg_pt_gp *tg_pt_gp;
140 	struct se_lun *lun;
141 	unsigned char *buf;
142 	u32 rd_len = 0, off;
143 	int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
144 
145 	/*
146 	 * Skip over RESERVED area to first Target port group descriptor
147 	 * depending on the PARAMETER DATA FORMAT type..
148 	 */
149 	if (ext_hdr != 0)
150 		off = 8;
151 	else
152 		off = 4;
153 
154 	if (cmd->data_length < off) {
155 		pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
156 			" small for %s header\n", cmd->data_length,
157 			(ext_hdr) ? "extended" : "normal");
158 		return TCM_INVALID_CDB_FIELD;
159 	}
160 	buf = transport_kmap_data_sg(cmd);
161 	if (!buf)
162 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
163 
164 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
165 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
166 			tg_pt_gp_list) {
167 		/* Skip empty port groups */
168 		if (!tg_pt_gp->tg_pt_gp_members)
169 			continue;
170 		/*
171 		 * Check if the Target port group and Target port descriptor list
172 		 * based on tg_pt_gp_members count will fit into the response payload.
173 		 * Otherwise, bump rd_len to let the initiator know we have exceeded
174 		 * the allocation length and the response is truncated.
175 		 */
176 		if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
177 		     cmd->data_length) {
178 			rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
179 			continue;
180 		}
181 		/*
182 		 * PREF: Preferred target port bit, determine if this
183 		 * bit should be set for port group.
184 		 */
185 		if (tg_pt_gp->tg_pt_gp_pref)
186 			buf[off] = 0x80;
187 		/*
188 		 * Set the ASYMMETRIC ACCESS State
189 		 */
190 		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_access_state & 0xff;
191 		/*
192 		 * Set supported ASYMMETRIC ACCESS State bits
193 		 */
194 		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
195 		/*
196 		 * TARGET PORT GROUP
197 		 */
198 		put_unaligned_be16(tg_pt_gp->tg_pt_gp_id, &buf[off]);
199 		off += 2;
200 
201 		off++; /* Skip over Reserved */
202 		/*
203 		 * STATUS CODE
204 		 */
205 		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
206 		/*
207 		 * Vendor Specific field
208 		 */
209 		buf[off++] = 0x00;
210 		/*
211 		 * TARGET PORT COUNT
212 		 */
213 		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
214 		rd_len += 8;
215 
216 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
217 		list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
218 				lun_tg_pt_gp_link) {
219 			/*
220 			 * Start Target Port descriptor format
221 			 *
222 			 * See spc4r17 section 6.2.7 Table 247
223 			 */
224 			off += 2; /* Skip over Obsolete */
225 			/*
226 			 * Set RELATIVE TARGET PORT IDENTIFIER
227 			 */
228 			put_unaligned_be16(lun->lun_tpg->tpg_rtpi, &buf[off]);
229 			off += 2;
230 			rd_len += 4;
231 		}
232 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
233 	}
234 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
235 	/*
236 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
237 	 */
238 	put_unaligned_be32(rd_len, &buf[0]);
239 
240 	/*
241 	 * Fill in the Extended header parameter data format if requested
242 	 */
243 	if (ext_hdr != 0) {
244 		buf[4] = 0x10;
245 		/*
246 		 * Set the implicit transition time (in seconds) for the application
247 		 * client to use as a base for it's transition timeout value.
248 		 *
249 		 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
250 		 * this CDB was received upon to determine this value individually
251 		 * for ALUA target port group.
252 		 */
253 		rcu_read_lock();
254 		tg_pt_gp = rcu_dereference(cmd->se_lun->lun_tg_pt_gp);
255 		if (tg_pt_gp)
256 			buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
257 		rcu_read_unlock();
258 	}
259 	transport_kunmap_data_sg(cmd);
260 
261 	target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, rd_len + 4);
262 	return 0;
263 }
264 
265 /*
266  * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
267  *
268  * See spc4r17 section 6.35
269  */
270 sense_reason_t
271 target_emulate_set_target_port_groups(struct se_cmd *cmd)
272 {
273 	struct se_device *dev = cmd->se_dev;
274 	struct se_lun *l_lun = cmd->se_lun;
275 	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
276 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
277 	unsigned char *buf;
278 	unsigned char *ptr;
279 	sense_reason_t rc = TCM_NO_SENSE;
280 	u32 len = 4; /* Skip over RESERVED area in header */
281 	int alua_access_state, primary = 0, valid_states;
282 	u16 tg_pt_id, rtpi;
283 
284 	if (cmd->data_length < 4) {
285 		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
286 			" small\n", cmd->data_length);
287 		return TCM_INVALID_PARAMETER_LIST;
288 	}
289 
290 	buf = transport_kmap_data_sg(cmd);
291 	if (!buf)
292 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
293 
294 	/*
295 	 * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
296 	 * for the local tg_pt_gp.
297 	 */
298 	rcu_read_lock();
299 	l_tg_pt_gp = rcu_dereference(l_lun->lun_tg_pt_gp);
300 	if (!l_tg_pt_gp) {
301 		rcu_read_unlock();
302 		pr_err("Unable to access l_lun->tg_pt_gp\n");
303 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
304 		goto out;
305 	}
306 
307 	if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
308 		rcu_read_unlock();
309 		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
310 				" while TPGS_EXPLICIT_ALUA is disabled\n");
311 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
312 		goto out;
313 	}
314 	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
315 	rcu_read_unlock();
316 
317 	ptr = &buf[4]; /* Skip over RESERVED area in header */
318 
319 	while (len < cmd->data_length) {
320 		bool found = false;
321 		alua_access_state = (ptr[0] & 0x0f);
322 		/*
323 		 * Check the received ALUA access state, and determine if
324 		 * the state is a primary or secondary target port asymmetric
325 		 * access state.
326 		 */
327 		rc = core_alua_check_transition(alua_access_state, valid_states,
328 						&primary, 1);
329 		if (rc) {
330 			/*
331 			 * If the SET TARGET PORT GROUPS attempts to establish
332 			 * an invalid combination of target port asymmetric
333 			 * access states or attempts to establish an
334 			 * unsupported target port asymmetric access state,
335 			 * then the command shall be terminated with CHECK
336 			 * CONDITION status, with the sense key set to ILLEGAL
337 			 * REQUEST, and the additional sense code set to INVALID
338 			 * FIELD IN PARAMETER LIST.
339 			 */
340 			goto out;
341 		}
342 
343 		/*
344 		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
345 		 * specifies a primary target port asymmetric access state,
346 		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
347 		 * a primary target port group for which the primary target
348 		 * port asymmetric access state shall be changed. If the
349 		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
350 		 * port asymmetric access state, then the TARGET PORT GROUP OR
351 		 * TARGET PORT field specifies the relative target port
352 		 * identifier (see 3.1.120) of the target port for which the
353 		 * secondary target port asymmetric access state shall be
354 		 * changed.
355 		 */
356 		if (primary) {
357 			tg_pt_id = get_unaligned_be16(ptr + 2);
358 			/*
359 			 * Locate the matching target port group ID from
360 			 * the global tg_pt_gp list
361 			 */
362 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
363 			list_for_each_entry(tg_pt_gp,
364 					&dev->t10_alua.tg_pt_gps_list,
365 					tg_pt_gp_list) {
366 				if (!tg_pt_gp->tg_pt_gp_valid_id)
367 					continue;
368 
369 				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
370 					continue;
371 
372 				atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
373 
374 				spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
375 
376 				if (!core_alua_do_port_transition(tg_pt_gp,
377 						dev, l_lun, nacl,
378 						alua_access_state, 1))
379 					found = true;
380 
381 				spin_lock(&dev->t10_alua.tg_pt_gps_lock);
382 				atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
383 				break;
384 			}
385 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
386 		} else {
387 			struct se_lun *lun;
388 
389 			/*
390 			 * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
391 			 * the Target Port in question for the incoming
392 			 * SET_TARGET_PORT_GROUPS op.
393 			 */
394 			rtpi = get_unaligned_be16(ptr + 2);
395 			/*
396 			 * Locate the matching relative target port identifier
397 			 * for the struct se_device storage object.
398 			 */
399 			spin_lock(&dev->se_port_lock);
400 			list_for_each_entry(lun, &dev->dev_sep_list,
401 							lun_dev_link) {
402 				if (lun->lun_tpg->tpg_rtpi != rtpi)
403 					continue;
404 
405 				// XXX: racy unlock
406 				spin_unlock(&dev->se_port_lock);
407 
408 				if (!core_alua_set_tg_pt_secondary_state(
409 						lun, 1, 1))
410 					found = true;
411 
412 				spin_lock(&dev->se_port_lock);
413 				break;
414 			}
415 			spin_unlock(&dev->se_port_lock);
416 		}
417 
418 		if (!found) {
419 			rc = TCM_INVALID_PARAMETER_LIST;
420 			goto out;
421 		}
422 
423 		ptr += 4;
424 		len += 4;
425 	}
426 
427 out:
428 	transport_kunmap_data_sg(cmd);
429 	if (!rc)
430 		target_complete_cmd(cmd, SAM_STAT_GOOD);
431 	return rc;
432 }
433 
434 static inline void core_alua_state_nonoptimized(
435 	struct se_cmd *cmd,
436 	unsigned char *cdb,
437 	int nonop_delay_msecs)
438 {
439 	/*
440 	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
441 	 * later to determine if processing of this cmd needs to be
442 	 * temporarily delayed for the Active/NonOptimized primary access state.
443 	 */
444 	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
445 	cmd->alua_nonop_delay = nonop_delay_msecs;
446 }
447 
448 static inline sense_reason_t core_alua_state_lba_dependent(
449 	struct se_cmd *cmd,
450 	u16 tg_pt_gp_id)
451 {
452 	struct se_device *dev = cmd->se_dev;
453 	u64 segment_size, segment_mult, sectors, lba;
454 
455 	/* Only need to check for cdb actually containing LBAs */
456 	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
457 		return 0;
458 
459 	spin_lock(&dev->t10_alua.lba_map_lock);
460 	segment_size = dev->t10_alua.lba_map_segment_size;
461 	segment_mult = dev->t10_alua.lba_map_segment_multiplier;
462 	sectors = cmd->data_length / dev->dev_attrib.block_size;
463 
464 	lba = cmd->t_task_lba;
465 	while (lba < cmd->t_task_lba + sectors) {
466 		struct t10_alua_lba_map *cur_map = NULL, *map;
467 		struct t10_alua_lba_map_member *map_mem;
468 
469 		list_for_each_entry(map, &dev->t10_alua.lba_map_list,
470 				    lba_map_list) {
471 			u64 start_lba, last_lba;
472 			u64 first_lba = map->lba_map_first_lba;
473 
474 			if (segment_mult) {
475 				u64 tmp = lba;
476 				start_lba = do_div(tmp, segment_size * segment_mult);
477 
478 				last_lba = first_lba + segment_size - 1;
479 				if (start_lba >= first_lba &&
480 				    start_lba <= last_lba) {
481 					lba += segment_size;
482 					cur_map = map;
483 					break;
484 				}
485 			} else {
486 				last_lba = map->lba_map_last_lba;
487 				if (lba >= first_lba && lba <= last_lba) {
488 					lba = last_lba + 1;
489 					cur_map = map;
490 					break;
491 				}
492 			}
493 		}
494 		if (!cur_map) {
495 			spin_unlock(&dev->t10_alua.lba_map_lock);
496 			return TCM_ALUA_TG_PT_UNAVAILABLE;
497 		}
498 		list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
499 				    lba_map_mem_list) {
500 			if (map_mem->lba_map_mem_alua_pg_id != tg_pt_gp_id)
501 				continue;
502 			switch(map_mem->lba_map_mem_alua_state) {
503 			case ALUA_ACCESS_STATE_STANDBY:
504 				spin_unlock(&dev->t10_alua.lba_map_lock);
505 				return TCM_ALUA_TG_PT_STANDBY;
506 			case ALUA_ACCESS_STATE_UNAVAILABLE:
507 				spin_unlock(&dev->t10_alua.lba_map_lock);
508 				return TCM_ALUA_TG_PT_UNAVAILABLE;
509 			default:
510 				break;
511 			}
512 		}
513 	}
514 	spin_unlock(&dev->t10_alua.lba_map_lock);
515 	return 0;
516 }
517 
518 static inline sense_reason_t core_alua_state_standby(
519 	struct se_cmd *cmd,
520 	unsigned char *cdb)
521 {
522 	/*
523 	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
524 	 * spc4r17 section 5.9.2.4.4
525 	 */
526 	switch (cdb[0]) {
527 	case INQUIRY:
528 	case LOG_SELECT:
529 	case LOG_SENSE:
530 	case MODE_SELECT:
531 	case MODE_SENSE:
532 	case REPORT_LUNS:
533 	case RECEIVE_DIAGNOSTIC:
534 	case SEND_DIAGNOSTIC:
535 	case READ_CAPACITY:
536 		return 0;
537 	case SERVICE_ACTION_IN_16:
538 		switch (cdb[1] & 0x1f) {
539 		case SAI_READ_CAPACITY_16:
540 			return 0;
541 		default:
542 			return TCM_ALUA_TG_PT_STANDBY;
543 		}
544 	case MAINTENANCE_IN:
545 		switch (cdb[1] & 0x1f) {
546 		case MI_REPORT_TARGET_PGS:
547 			return 0;
548 		default:
549 			return TCM_ALUA_TG_PT_STANDBY;
550 		}
551 	case MAINTENANCE_OUT:
552 		switch (cdb[1]) {
553 		case MO_SET_TARGET_PGS:
554 			return 0;
555 		default:
556 			return TCM_ALUA_TG_PT_STANDBY;
557 		}
558 	case REQUEST_SENSE:
559 	case PERSISTENT_RESERVE_IN:
560 	case PERSISTENT_RESERVE_OUT:
561 	case READ_BUFFER:
562 	case WRITE_BUFFER:
563 		return 0;
564 	default:
565 		return TCM_ALUA_TG_PT_STANDBY;
566 	}
567 
568 	return 0;
569 }
570 
571 static inline sense_reason_t core_alua_state_unavailable(
572 	struct se_cmd *cmd,
573 	unsigned char *cdb)
574 {
575 	/*
576 	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
577 	 * spc4r17 section 5.9.2.4.5
578 	 */
579 	switch (cdb[0]) {
580 	case INQUIRY:
581 	case REPORT_LUNS:
582 		return 0;
583 	case MAINTENANCE_IN:
584 		switch (cdb[1] & 0x1f) {
585 		case MI_REPORT_TARGET_PGS:
586 			return 0;
587 		default:
588 			return TCM_ALUA_TG_PT_UNAVAILABLE;
589 		}
590 	case MAINTENANCE_OUT:
591 		switch (cdb[1]) {
592 		case MO_SET_TARGET_PGS:
593 			return 0;
594 		default:
595 			return TCM_ALUA_TG_PT_UNAVAILABLE;
596 		}
597 	case REQUEST_SENSE:
598 	case READ_BUFFER:
599 	case WRITE_BUFFER:
600 		return 0;
601 	default:
602 		return TCM_ALUA_TG_PT_UNAVAILABLE;
603 	}
604 
605 	return 0;
606 }
607 
608 static inline sense_reason_t core_alua_state_transition(
609 	struct se_cmd *cmd,
610 	unsigned char *cdb)
611 {
612 	/*
613 	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
614 	 * spc4r17 section 5.9.2.5
615 	 */
616 	switch (cdb[0]) {
617 	case INQUIRY:
618 	case REPORT_LUNS:
619 		return 0;
620 	case MAINTENANCE_IN:
621 		switch (cdb[1] & 0x1f) {
622 		case MI_REPORT_TARGET_PGS:
623 			return 0;
624 		default:
625 			return TCM_ALUA_STATE_TRANSITION;
626 		}
627 	case REQUEST_SENSE:
628 	case READ_BUFFER:
629 	case WRITE_BUFFER:
630 		return 0;
631 	default:
632 		return TCM_ALUA_STATE_TRANSITION;
633 	}
634 
635 	return 0;
636 }
637 
638 /*
639  * return 1: Is used to signal LUN not accessible, and check condition/not ready
640  * return 0: Used to signal success
641  * return -1: Used to signal failure, and invalid cdb field
642  */
643 sense_reason_t
644 target_alua_state_check(struct se_cmd *cmd)
645 {
646 	struct se_device *dev = cmd->se_dev;
647 	unsigned char *cdb = cmd->t_task_cdb;
648 	struct se_lun *lun = cmd->se_lun;
649 	struct t10_alua_tg_pt_gp *tg_pt_gp;
650 	int out_alua_state, nonop_delay_msecs;
651 	u16 tg_pt_gp_id;
652 	sense_reason_t rc = TCM_NO_SENSE;
653 
654 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
655 		return 0;
656 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
657 		return 0;
658 
659 	/*
660 	 * First, check for a struct se_port specific secondary ALUA target port
661 	 * access state: OFFLINE
662 	 */
663 	if (atomic_read(&lun->lun_tg_pt_secondary_offline)) {
664 		pr_debug("ALUA: Got secondary offline status for local"
665 				" target port\n");
666 		return TCM_ALUA_OFFLINE;
667 	}
668 	rcu_read_lock();
669 	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
670 	if (!tg_pt_gp) {
671 		rcu_read_unlock();
672 		return 0;
673 	}
674 
675 	out_alua_state = tg_pt_gp->tg_pt_gp_alua_access_state;
676 	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
677 	tg_pt_gp_id = tg_pt_gp->tg_pt_gp_id;
678 	rcu_read_unlock();
679 	/*
680 	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
681 	 * statement so the compiler knows explicitly to check this case first.
682 	 * For the Optimized ALUA access state case, we want to process the
683 	 * incoming fabric cmd ASAP..
684 	 */
685 	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
686 		return 0;
687 
688 	switch (out_alua_state) {
689 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
690 		core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
691 		break;
692 	case ALUA_ACCESS_STATE_STANDBY:
693 		rc = core_alua_state_standby(cmd, cdb);
694 		break;
695 	case ALUA_ACCESS_STATE_UNAVAILABLE:
696 		rc = core_alua_state_unavailable(cmd, cdb);
697 		break;
698 	case ALUA_ACCESS_STATE_TRANSITION:
699 		rc = core_alua_state_transition(cmd, cdb);
700 		break;
701 	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
702 		rc = core_alua_state_lba_dependent(cmd, tg_pt_gp_id);
703 		break;
704 	/*
705 	 * OFFLINE is a secondary ALUA target port group access state, that is
706 	 * handled above with struct se_lun->lun_tg_pt_secondary_offline=1
707 	 */
708 	case ALUA_ACCESS_STATE_OFFLINE:
709 	default:
710 		pr_err("Unknown ALUA access state: 0x%02x\n",
711 				out_alua_state);
712 		rc = TCM_INVALID_CDB_FIELD;
713 	}
714 
715 	if (rc && rc != TCM_INVALID_CDB_FIELD) {
716 		pr_debug("[%s]: ALUA TG Port not available, "
717 			"SenseKey: NOT_READY, ASC/rc: 0x04/%d\n",
718 			cmd->se_tfo->fabric_name, rc);
719 	}
720 
721 	return rc;
722 }
723 
724 /*
725  * Check implicit and explicit ALUA state change request.
726  */
727 static sense_reason_t
728 core_alua_check_transition(int state, int valid, int *primary, int explicit)
729 {
730 	/*
731 	 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
732 	 * defined as primary target port asymmetric access states.
733 	 */
734 	switch (state) {
735 	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
736 		if (!(valid & ALUA_AO_SUP))
737 			goto not_supported;
738 		*primary = 1;
739 		break;
740 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
741 		if (!(valid & ALUA_AN_SUP))
742 			goto not_supported;
743 		*primary = 1;
744 		break;
745 	case ALUA_ACCESS_STATE_STANDBY:
746 		if (!(valid & ALUA_S_SUP))
747 			goto not_supported;
748 		*primary = 1;
749 		break;
750 	case ALUA_ACCESS_STATE_UNAVAILABLE:
751 		if (!(valid & ALUA_U_SUP))
752 			goto not_supported;
753 		*primary = 1;
754 		break;
755 	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
756 		if (!(valid & ALUA_LBD_SUP))
757 			goto not_supported;
758 		*primary = 1;
759 		break;
760 	case ALUA_ACCESS_STATE_OFFLINE:
761 		/*
762 		 * OFFLINE state is defined as a secondary target port
763 		 * asymmetric access state.
764 		 */
765 		if (!(valid & ALUA_O_SUP))
766 			goto not_supported;
767 		*primary = 0;
768 		break;
769 	case ALUA_ACCESS_STATE_TRANSITION:
770 		if (!(valid & ALUA_T_SUP) || explicit)
771 			/*
772 			 * Transitioning is set internally and by tcmu daemon,
773 			 * and cannot be selected through a STPG.
774 			 */
775 			goto not_supported;
776 		*primary = 0;
777 		break;
778 	default:
779 		pr_err("Unknown ALUA access state: 0x%02x\n", state);
780 		return TCM_INVALID_PARAMETER_LIST;
781 	}
782 
783 	return 0;
784 
785 not_supported:
786 	pr_err("ALUA access state %s not supported",
787 	       core_alua_dump_state(state));
788 	return TCM_INVALID_PARAMETER_LIST;
789 }
790 
791 static char *core_alua_dump_state(int state)
792 {
793 	switch (state) {
794 	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
795 		return "Active/Optimized";
796 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
797 		return "Active/NonOptimized";
798 	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
799 		return "LBA Dependent";
800 	case ALUA_ACCESS_STATE_STANDBY:
801 		return "Standby";
802 	case ALUA_ACCESS_STATE_UNAVAILABLE:
803 		return "Unavailable";
804 	case ALUA_ACCESS_STATE_OFFLINE:
805 		return "Offline";
806 	case ALUA_ACCESS_STATE_TRANSITION:
807 		return "Transitioning";
808 	default:
809 		return "Unknown";
810 	}
811 
812 	return NULL;
813 }
814 
815 char *core_alua_dump_status(int status)
816 {
817 	switch (status) {
818 	case ALUA_STATUS_NONE:
819 		return "None";
820 	case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
821 		return "Altered by Explicit STPG";
822 	case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
823 		return "Altered by Implicit ALUA";
824 	default:
825 		return "Unknown";
826 	}
827 
828 	return NULL;
829 }
830 
831 /*
832  * Used by fabric modules to determine when we need to delay processing
833  * for the Active/NonOptimized paths..
834  */
835 int core_alua_check_nonop_delay(
836 	struct se_cmd *cmd)
837 {
838 	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
839 		return 0;
840 	/*
841 	 * The ALUA Active/NonOptimized access state delay can be disabled
842 	 * in via configfs with a value of zero
843 	 */
844 	if (!cmd->alua_nonop_delay)
845 		return 0;
846 	/*
847 	 * struct se_cmd->alua_nonop_delay gets set by a target port group
848 	 * defined interval in core_alua_state_nonoptimized()
849 	 */
850 	msleep_interruptible(cmd->alua_nonop_delay);
851 	return 0;
852 }
853 
854 static int core_alua_write_tpg_metadata(
855 	const char *path,
856 	unsigned char *md_buf,
857 	u32 md_buf_len)
858 {
859 	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
860 	loff_t pos = 0;
861 	int ret;
862 
863 	if (IS_ERR(file)) {
864 		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
865 		return -ENODEV;
866 	}
867 	ret = kernel_write(file, md_buf, md_buf_len, &pos);
868 	if (ret < 0)
869 		pr_err("Error writing ALUA metadata file: %s\n", path);
870 	fput(file);
871 	return (ret < 0) ? -EIO : 0;
872 }
873 
874 static int core_alua_update_tpg_primary_metadata(
875 	struct t10_alua_tg_pt_gp *tg_pt_gp)
876 {
877 	unsigned char *md_buf;
878 	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
879 	char *path;
880 	int len, rc;
881 
882 	lockdep_assert_held(&tg_pt_gp->tg_pt_gp_transition_mutex);
883 
884 	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
885 	if (!md_buf) {
886 		pr_err("Unable to allocate buf for ALUA metadata\n");
887 		return -ENOMEM;
888 	}
889 
890 	len = snprintf(md_buf, ALUA_MD_BUF_LEN,
891 			"tg_pt_gp_id=%hu\n"
892 			"alua_access_state=0x%02x\n"
893 			"alua_access_status=0x%02x\n",
894 			tg_pt_gp->tg_pt_gp_id,
895 			tg_pt_gp->tg_pt_gp_alua_access_state,
896 			tg_pt_gp->tg_pt_gp_alua_access_status);
897 
898 	rc = -ENOMEM;
899 	path = kasprintf(GFP_KERNEL, "%s/alua/tpgs_%s/%s", db_root,
900 			&wwn->unit_serial[0],
901 			config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
902 	if (path) {
903 		rc = core_alua_write_tpg_metadata(path, md_buf, len);
904 		kfree(path);
905 	}
906 	kfree(md_buf);
907 	return rc;
908 }
909 
910 static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
911 {
912 	struct se_dev_entry *se_deve;
913 	struct se_lun *lun;
914 	struct se_lun_acl *lacl;
915 
916 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
917 	list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
918 				lun_tg_pt_gp_link) {
919 		/*
920 		 * After an implicit target port asymmetric access state
921 		 * change, a device server shall establish a unit attention
922 		 * condition for the initiator port associated with every I_T
923 		 * nexus with the additional sense code set to ASYMMETRIC
924 		 * ACCESS STATE CHANGED.
925 		 *
926 		 * After an explicit target port asymmetric access state
927 		 * change, a device server shall establish a unit attention
928 		 * condition with the additional sense code set to ASYMMETRIC
929 		 * ACCESS STATE CHANGED for the initiator port associated with
930 		 * every I_T nexus other than the I_T nexus on which the SET
931 		 * TARGET PORT GROUPS command
932 		 */
933 		if (!percpu_ref_tryget_live(&lun->lun_ref))
934 			continue;
935 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
936 
937 		spin_lock(&lun->lun_deve_lock);
938 		list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
939 			lacl = se_deve->se_lun_acl;
940 
941 			/*
942 			 * spc4r37 p.242:
943 			 * After an explicit target port asymmetric access
944 			 * state change, a device server shall establish a
945 			 * unit attention condition with the additional sense
946 			 * code set to ASYMMETRIC ACCESS STATE CHANGED for
947 			 * the initiator port associated with every I_T nexus
948 			 * other than the I_T nexus on which the SET TARGET
949 			 * PORT GROUPS command was received.
950 			 */
951 			if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
952 			     ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
953 			   (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
954 			    (tg_pt_gp->tg_pt_gp_alua_lun == lun))
955 				continue;
956 
957 			/*
958 			 * se_deve->se_lun_acl pointer may be NULL for a
959 			 * entry created without explicit Node+MappedLUN ACLs
960 			 */
961 			if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
962 			    (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
963 				continue;
964 
965 			core_scsi3_ua_allocate(se_deve, 0x2A,
966 				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
967 		}
968 		spin_unlock(&lun->lun_deve_lock);
969 
970 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
971 		percpu_ref_put(&lun->lun_ref);
972 	}
973 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
974 }
975 
976 static int core_alua_do_transition_tg_pt(
977 	struct t10_alua_tg_pt_gp *tg_pt_gp,
978 	int new_state,
979 	int explicit)
980 {
981 	int prev_state;
982 
983 	mutex_lock(&tg_pt_gp->tg_pt_gp_transition_mutex);
984 	/* Nothing to be done here */
985 	if (tg_pt_gp->tg_pt_gp_alua_access_state == new_state) {
986 		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
987 		return 0;
988 	}
989 
990 	if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION) {
991 		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
992 		return -EAGAIN;
993 	}
994 
995 	/*
996 	 * Save the old primary ALUA access state, and set the current state
997 	 * to ALUA_ACCESS_STATE_TRANSITION.
998 	 */
999 	prev_state = tg_pt_gp->tg_pt_gp_alua_access_state;
1000 	tg_pt_gp->tg_pt_gp_alua_access_state = ALUA_ACCESS_STATE_TRANSITION;
1001 	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
1002 				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1003 				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1004 
1005 	core_alua_queue_state_change_ua(tg_pt_gp);
1006 
1007 	if (new_state == ALUA_ACCESS_STATE_TRANSITION) {
1008 		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1009 		return 0;
1010 	}
1011 
1012 	/*
1013 	 * Check for the optional ALUA primary state transition delay
1014 	 */
1015 	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
1016 		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1017 
1018 	/*
1019 	 * Set the current primary ALUA access state to the requested new state
1020 	 */
1021 	tg_pt_gp->tg_pt_gp_alua_access_state = new_state;
1022 
1023 	/*
1024 	 * Update the ALUA metadata buf that has been allocated in
1025 	 * core_alua_do_port_transition(), this metadata will be written
1026 	 * to struct file.
1027 	 *
1028 	 * Note that there is the case where we do not want to update the
1029 	 * metadata when the saved metadata is being parsed in userspace
1030 	 * when setting the existing port access state and access status.
1031 	 *
1032 	 * Also note that the failure to write out the ALUA metadata to
1033 	 * struct file does NOT affect the actual ALUA transition.
1034 	 */
1035 	if (tg_pt_gp->tg_pt_gp_write_metadata) {
1036 		core_alua_update_tpg_primary_metadata(tg_pt_gp);
1037 	}
1038 
1039 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1040 		" from primary access state %s to %s\n", (explicit) ? "explicit" :
1041 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1042 		tg_pt_gp->tg_pt_gp_id,
1043 		core_alua_dump_state(prev_state),
1044 		core_alua_dump_state(new_state));
1045 
1046 	core_alua_queue_state_change_ua(tg_pt_gp);
1047 
1048 	mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1049 	return 0;
1050 }
1051 
1052 int core_alua_do_port_transition(
1053 	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
1054 	struct se_device *l_dev,
1055 	struct se_lun *l_lun,
1056 	struct se_node_acl *l_nacl,
1057 	int new_state,
1058 	int explicit)
1059 {
1060 	struct se_device *dev;
1061 	struct t10_alua_lu_gp *lu_gp;
1062 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
1063 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1064 	int primary, valid_states, rc = 0;
1065 
1066 	if (l_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
1067 		return -ENODEV;
1068 
1069 	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
1070 	if (core_alua_check_transition(new_state, valid_states, &primary,
1071 				       explicit) != 0)
1072 		return -EINVAL;
1073 
1074 	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
1075 	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
1076 	lu_gp = local_lu_gp_mem->lu_gp;
1077 	atomic_inc(&lu_gp->lu_gp_ref_cnt);
1078 	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
1079 	/*
1080 	 * For storage objects that are members of the 'default_lu_gp',
1081 	 * we only do transition on the passed *l_tp_pt_gp, and not
1082 	 * on all of the matching target port groups IDs in default_lu_gp.
1083 	 */
1084 	if (!lu_gp->lu_gp_id) {
1085 		/*
1086 		 * core_alua_do_transition_tg_pt() will always return
1087 		 * success.
1088 		 */
1089 		l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1090 		l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1091 		rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
1092 						   new_state, explicit);
1093 		atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1094 		return rc;
1095 	}
1096 	/*
1097 	 * For all other LU groups aside from 'default_lu_gp', walk all of
1098 	 * the associated storage objects looking for a matching target port
1099 	 * group ID from the local target port group.
1100 	 */
1101 	spin_lock(&lu_gp->lu_gp_lock);
1102 	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
1103 				lu_gp_mem_list) {
1104 
1105 		dev = lu_gp_mem->lu_gp_mem_dev;
1106 		atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1107 		spin_unlock(&lu_gp->lu_gp_lock);
1108 
1109 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1110 		list_for_each_entry(tg_pt_gp,
1111 				&dev->t10_alua.tg_pt_gps_list,
1112 				tg_pt_gp_list) {
1113 
1114 			if (!tg_pt_gp->tg_pt_gp_valid_id)
1115 				continue;
1116 			/*
1117 			 * If the target behavior port asymmetric access state
1118 			 * is changed for any target port group accessible via
1119 			 * a logical unit within a LU group, the target port
1120 			 * behavior group asymmetric access states for the same
1121 			 * target port group accessible via other logical units
1122 			 * in that LU group will also change.
1123 			 */
1124 			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
1125 				continue;
1126 
1127 			if (l_tg_pt_gp == tg_pt_gp) {
1128 				tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1129 				tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1130 			} else {
1131 				tg_pt_gp->tg_pt_gp_alua_lun = NULL;
1132 				tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
1133 			}
1134 			atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1135 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1136 			/*
1137 			 * core_alua_do_transition_tg_pt() will always return
1138 			 * success.
1139 			 */
1140 			rc = core_alua_do_transition_tg_pt(tg_pt_gp,
1141 					new_state, explicit);
1142 
1143 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1144 			atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1145 			if (rc)
1146 				break;
1147 		}
1148 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1149 
1150 		spin_lock(&lu_gp->lu_gp_lock);
1151 		atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1152 	}
1153 	spin_unlock(&lu_gp->lu_gp_lock);
1154 
1155 	if (!rc) {
1156 		pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1157 			 " Group IDs: %hu %s transition to primary state: %s\n",
1158 			 config_item_name(&lu_gp->lu_gp_group.cg_item),
1159 			 l_tg_pt_gp->tg_pt_gp_id,
1160 			 (explicit) ? "explicit" : "implicit",
1161 			 core_alua_dump_state(new_state));
1162 	}
1163 
1164 	atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1165 	return rc;
1166 }
1167 
1168 static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
1169 {
1170 	struct se_portal_group *se_tpg = lun->lun_tpg;
1171 	unsigned char *md_buf;
1172 	char *path;
1173 	int len, rc;
1174 
1175 	mutex_lock(&lun->lun_tg_pt_md_mutex);
1176 
1177 	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
1178 	if (!md_buf) {
1179 		pr_err("Unable to allocate buf for ALUA metadata\n");
1180 		rc = -ENOMEM;
1181 		goto out_unlock;
1182 	}
1183 
1184 	len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
1185 			"alua_tg_pt_status=0x%02x\n",
1186 			atomic_read(&lun->lun_tg_pt_secondary_offline),
1187 			lun->lun_tg_pt_secondary_stat);
1188 
1189 	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL) {
1190 		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s+%hu/lun_%llu",
1191 				db_root, se_tpg->se_tpg_tfo->fabric_name,
1192 				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1193 				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg),
1194 				lun->unpacked_lun);
1195 	} else {
1196 		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s/lun_%llu",
1197 				db_root, se_tpg->se_tpg_tfo->fabric_name,
1198 				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1199 				lun->unpacked_lun);
1200 	}
1201 	if (!path) {
1202 		rc = -ENOMEM;
1203 		goto out_free;
1204 	}
1205 
1206 	rc = core_alua_write_tpg_metadata(path, md_buf, len);
1207 	kfree(path);
1208 out_free:
1209 	kfree(md_buf);
1210 out_unlock:
1211 	mutex_unlock(&lun->lun_tg_pt_md_mutex);
1212 	return rc;
1213 }
1214 
1215 static int core_alua_set_tg_pt_secondary_state(
1216 	struct se_lun *lun,
1217 	int explicit,
1218 	int offline)
1219 {
1220 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1221 	int trans_delay_msecs;
1222 
1223 	rcu_read_lock();
1224 	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
1225 	if (!tg_pt_gp) {
1226 		rcu_read_unlock();
1227 		pr_err("Unable to complete secondary state"
1228 				" transition\n");
1229 		return -EINVAL;
1230 	}
1231 	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1232 	/*
1233 	 * Set the secondary ALUA target port access state to OFFLINE
1234 	 * or release the previously secondary state for struct se_lun
1235 	 */
1236 	if (offline)
1237 		atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
1238 	else
1239 		atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
1240 
1241 	lun->lun_tg_pt_secondary_stat = (explicit) ?
1242 			ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1243 			ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1244 
1245 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1246 		" to secondary access state: %s\n", (explicit) ? "explicit" :
1247 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1248 		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1249 
1250 	rcu_read_unlock();
1251 	/*
1252 	 * Do the optional transition delay after we set the secondary
1253 	 * ALUA access state.
1254 	 */
1255 	if (trans_delay_msecs != 0)
1256 		msleep_interruptible(trans_delay_msecs);
1257 	/*
1258 	 * See if we need to update the ALUA fabric port metadata for
1259 	 * secondary state and status
1260 	 */
1261 	if (lun->lun_tg_pt_secondary_write_md)
1262 		core_alua_update_tpg_secondary_metadata(lun);
1263 
1264 	return 0;
1265 }
1266 
1267 struct t10_alua_lba_map *
1268 core_alua_allocate_lba_map(struct list_head *list,
1269 			   u64 first_lba, u64 last_lba)
1270 {
1271 	struct t10_alua_lba_map *lba_map;
1272 
1273 	lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
1274 	if (!lba_map) {
1275 		pr_err("Unable to allocate struct t10_alua_lba_map\n");
1276 		return ERR_PTR(-ENOMEM);
1277 	}
1278 	INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
1279 	lba_map->lba_map_first_lba = first_lba;
1280 	lba_map->lba_map_last_lba = last_lba;
1281 
1282 	list_add_tail(&lba_map->lba_map_list, list);
1283 	return lba_map;
1284 }
1285 
1286 int
1287 core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
1288 			       int pg_id, int state)
1289 {
1290 	struct t10_alua_lba_map_member *lba_map_mem;
1291 
1292 	list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
1293 			    lba_map_mem_list) {
1294 		if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
1295 			pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
1296 			return -EINVAL;
1297 		}
1298 	}
1299 
1300 	lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
1301 	if (!lba_map_mem) {
1302 		pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
1303 		return -ENOMEM;
1304 	}
1305 	lba_map_mem->lba_map_mem_alua_state = state;
1306 	lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
1307 
1308 	list_add_tail(&lba_map_mem->lba_map_mem_list,
1309 		      &lba_map->lba_map_mem_list);
1310 	return 0;
1311 }
1312 
1313 void
1314 core_alua_free_lba_map(struct list_head *lba_list)
1315 {
1316 	struct t10_alua_lba_map *lba_map, *lba_map_tmp;
1317 	struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
1318 
1319 	list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
1320 				 lba_map_list) {
1321 		list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
1322 					 &lba_map->lba_map_mem_list,
1323 					 lba_map_mem_list) {
1324 			list_del(&lba_map_mem->lba_map_mem_list);
1325 			kmem_cache_free(t10_alua_lba_map_mem_cache,
1326 					lba_map_mem);
1327 		}
1328 		list_del(&lba_map->lba_map_list);
1329 		kmem_cache_free(t10_alua_lba_map_cache, lba_map);
1330 	}
1331 }
1332 
1333 void
1334 core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
1335 		      int segment_size, int segment_mult)
1336 {
1337 	struct list_head old_lba_map_list;
1338 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1339 	int activate = 0, supported;
1340 
1341 	INIT_LIST_HEAD(&old_lba_map_list);
1342 	spin_lock(&dev->t10_alua.lba_map_lock);
1343 	dev->t10_alua.lba_map_segment_size = segment_size;
1344 	dev->t10_alua.lba_map_segment_multiplier = segment_mult;
1345 	list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
1346 	if (lba_map_list) {
1347 		list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
1348 		activate = 1;
1349 	}
1350 	spin_unlock(&dev->t10_alua.lba_map_lock);
1351 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1352 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1353 			    tg_pt_gp_list) {
1354 
1355 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1356 			continue;
1357 		supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
1358 		if (activate)
1359 			supported |= ALUA_LBD_SUP;
1360 		else
1361 			supported &= ~ALUA_LBD_SUP;
1362 		tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
1363 	}
1364 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1365 	core_alua_free_lba_map(&old_lba_map_list);
1366 }
1367 
1368 struct t10_alua_lu_gp *
1369 core_alua_allocate_lu_gp(const char *name, int def_group)
1370 {
1371 	struct t10_alua_lu_gp *lu_gp;
1372 
1373 	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1374 	if (!lu_gp) {
1375 		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1376 		return ERR_PTR(-ENOMEM);
1377 	}
1378 	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1379 	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1380 	spin_lock_init(&lu_gp->lu_gp_lock);
1381 	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1382 
1383 	if (def_group) {
1384 		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1385 		lu_gp->lu_gp_valid_id = 1;
1386 		alua_lu_gps_count++;
1387 	}
1388 
1389 	return lu_gp;
1390 }
1391 
1392 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1393 {
1394 	struct t10_alua_lu_gp *lu_gp_tmp;
1395 	u16 lu_gp_id_tmp;
1396 	/*
1397 	 * The lu_gp->lu_gp_id may only be set once..
1398 	 */
1399 	if (lu_gp->lu_gp_valid_id) {
1400 		pr_warn("ALUA LU Group already has a valid ID,"
1401 			" ignoring request\n");
1402 		return -EINVAL;
1403 	}
1404 
1405 	spin_lock(&lu_gps_lock);
1406 	if (alua_lu_gps_count == 0x0000ffff) {
1407 		pr_err("Maximum ALUA alua_lu_gps_count:"
1408 				" 0x0000ffff reached\n");
1409 		spin_unlock(&lu_gps_lock);
1410 		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1411 		return -ENOSPC;
1412 	}
1413 again:
1414 	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1415 				alua_lu_gps_counter++;
1416 
1417 	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1418 		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1419 			if (!lu_gp_id)
1420 				goto again;
1421 
1422 			pr_warn("ALUA Logical Unit Group ID: %hu"
1423 				" already exists, ignoring request\n",
1424 				lu_gp_id);
1425 			spin_unlock(&lu_gps_lock);
1426 			return -EINVAL;
1427 		}
1428 	}
1429 
1430 	lu_gp->lu_gp_id = lu_gp_id_tmp;
1431 	lu_gp->lu_gp_valid_id = 1;
1432 	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1433 	alua_lu_gps_count++;
1434 	spin_unlock(&lu_gps_lock);
1435 
1436 	return 0;
1437 }
1438 
1439 static struct t10_alua_lu_gp_member *
1440 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1441 {
1442 	struct t10_alua_lu_gp_member *lu_gp_mem;
1443 
1444 	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1445 	if (!lu_gp_mem) {
1446 		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1447 		return ERR_PTR(-ENOMEM);
1448 	}
1449 	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1450 	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1451 	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1452 
1453 	lu_gp_mem->lu_gp_mem_dev = dev;
1454 	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1455 
1456 	return lu_gp_mem;
1457 }
1458 
1459 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1460 {
1461 	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1462 	/*
1463 	 * Once we have reached this point, config_item_put() has
1464 	 * already been called from target_core_alua_drop_lu_gp().
1465 	 *
1466 	 * Here, we remove the *lu_gp from the global list so that
1467 	 * no associations can be made while we are releasing
1468 	 * struct t10_alua_lu_gp.
1469 	 */
1470 	spin_lock(&lu_gps_lock);
1471 	list_del(&lu_gp->lu_gp_node);
1472 	alua_lu_gps_count--;
1473 	spin_unlock(&lu_gps_lock);
1474 	/*
1475 	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1476 	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1477 	 * released with core_alua_put_lu_gp_from_name()
1478 	 */
1479 	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1480 		cpu_relax();
1481 	/*
1482 	 * Release reference to struct t10_alua_lu_gp * from all associated
1483 	 * struct se_device.
1484 	 */
1485 	spin_lock(&lu_gp->lu_gp_lock);
1486 	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1487 				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1488 		if (lu_gp_mem->lu_gp_assoc) {
1489 			list_del(&lu_gp_mem->lu_gp_mem_list);
1490 			lu_gp->lu_gp_members--;
1491 			lu_gp_mem->lu_gp_assoc = 0;
1492 		}
1493 		spin_unlock(&lu_gp->lu_gp_lock);
1494 		/*
1495 		 *
1496 		 * lu_gp_mem is associated with a single
1497 		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1498 		 * struct se_device is released via core_alua_free_lu_gp_mem().
1499 		 *
1500 		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1501 		 * we want to re-associate a given lu_gp_mem with default_lu_gp.
1502 		 */
1503 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1504 		if (lu_gp != default_lu_gp)
1505 			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1506 					default_lu_gp);
1507 		else
1508 			lu_gp_mem->lu_gp = NULL;
1509 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1510 
1511 		spin_lock(&lu_gp->lu_gp_lock);
1512 	}
1513 	spin_unlock(&lu_gp->lu_gp_lock);
1514 
1515 	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1516 }
1517 
1518 void core_alua_free_lu_gp_mem(struct se_device *dev)
1519 {
1520 	struct t10_alua_lu_gp *lu_gp;
1521 	struct t10_alua_lu_gp_member *lu_gp_mem;
1522 
1523 	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1524 	if (!lu_gp_mem)
1525 		return;
1526 
1527 	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1528 		cpu_relax();
1529 
1530 	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1531 	lu_gp = lu_gp_mem->lu_gp;
1532 	if (lu_gp) {
1533 		spin_lock(&lu_gp->lu_gp_lock);
1534 		if (lu_gp_mem->lu_gp_assoc) {
1535 			list_del(&lu_gp_mem->lu_gp_mem_list);
1536 			lu_gp->lu_gp_members--;
1537 			lu_gp_mem->lu_gp_assoc = 0;
1538 		}
1539 		spin_unlock(&lu_gp->lu_gp_lock);
1540 		lu_gp_mem->lu_gp = NULL;
1541 	}
1542 	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1543 
1544 	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1545 }
1546 
1547 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1548 {
1549 	struct t10_alua_lu_gp *lu_gp;
1550 	struct config_item *ci;
1551 
1552 	spin_lock(&lu_gps_lock);
1553 	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1554 		if (!lu_gp->lu_gp_valid_id)
1555 			continue;
1556 		ci = &lu_gp->lu_gp_group.cg_item;
1557 		if (!strcmp(config_item_name(ci), name)) {
1558 			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1559 			spin_unlock(&lu_gps_lock);
1560 			return lu_gp;
1561 		}
1562 	}
1563 	spin_unlock(&lu_gps_lock);
1564 
1565 	return NULL;
1566 }
1567 
1568 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1569 {
1570 	spin_lock(&lu_gps_lock);
1571 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1572 	spin_unlock(&lu_gps_lock);
1573 }
1574 
1575 /*
1576  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1577  */
1578 void __core_alua_attach_lu_gp_mem(
1579 	struct t10_alua_lu_gp_member *lu_gp_mem,
1580 	struct t10_alua_lu_gp *lu_gp)
1581 {
1582 	spin_lock(&lu_gp->lu_gp_lock);
1583 	lu_gp_mem->lu_gp = lu_gp;
1584 	lu_gp_mem->lu_gp_assoc = 1;
1585 	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1586 	lu_gp->lu_gp_members++;
1587 	spin_unlock(&lu_gp->lu_gp_lock);
1588 }
1589 
1590 /*
1591  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1592  */
1593 void __core_alua_drop_lu_gp_mem(
1594 	struct t10_alua_lu_gp_member *lu_gp_mem,
1595 	struct t10_alua_lu_gp *lu_gp)
1596 {
1597 	spin_lock(&lu_gp->lu_gp_lock);
1598 	list_del(&lu_gp_mem->lu_gp_mem_list);
1599 	lu_gp_mem->lu_gp = NULL;
1600 	lu_gp_mem->lu_gp_assoc = 0;
1601 	lu_gp->lu_gp_members--;
1602 	spin_unlock(&lu_gp->lu_gp_lock);
1603 }
1604 
1605 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1606 		const char *name, int def_group)
1607 {
1608 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1609 
1610 	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1611 	if (!tg_pt_gp) {
1612 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1613 		return NULL;
1614 	}
1615 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1616 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
1617 	mutex_init(&tg_pt_gp->tg_pt_gp_transition_mutex);
1618 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1619 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1620 	tg_pt_gp->tg_pt_gp_dev = dev;
1621 	tg_pt_gp->tg_pt_gp_alua_access_state =
1622 			ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
1623 	/*
1624 	 * Enable both explicit and implicit ALUA support by default
1625 	 */
1626 	tg_pt_gp->tg_pt_gp_alua_access_type =
1627 			TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1628 	/*
1629 	 * Set the default Active/NonOptimized Delay in milliseconds
1630 	 */
1631 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1632 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1633 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1634 
1635 	/*
1636 	 * Enable all supported states
1637 	 */
1638 	tg_pt_gp->tg_pt_gp_alua_supported_states =
1639 	    ALUA_T_SUP | ALUA_O_SUP |
1640 	    ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1641 
1642 	if (def_group) {
1643 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1644 		tg_pt_gp->tg_pt_gp_id =
1645 				dev->t10_alua.alua_tg_pt_gps_counter++;
1646 		tg_pt_gp->tg_pt_gp_valid_id = 1;
1647 		dev->t10_alua.alua_tg_pt_gps_count++;
1648 		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1649 			      &dev->t10_alua.tg_pt_gps_list);
1650 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1651 	}
1652 
1653 	return tg_pt_gp;
1654 }
1655 
1656 int core_alua_set_tg_pt_gp_id(
1657 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1658 	u16 tg_pt_gp_id)
1659 {
1660 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1661 	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1662 	u16 tg_pt_gp_id_tmp;
1663 
1664 	/*
1665 	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1666 	 */
1667 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1668 		pr_warn("ALUA TG PT Group already has a valid ID,"
1669 			" ignoring request\n");
1670 		return -EINVAL;
1671 	}
1672 
1673 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1674 	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1675 		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1676 			" 0x0000ffff reached\n");
1677 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1678 		return -ENOSPC;
1679 	}
1680 again:
1681 	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1682 			dev->t10_alua.alua_tg_pt_gps_counter++;
1683 
1684 	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1685 			tg_pt_gp_list) {
1686 		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1687 			if (!tg_pt_gp_id)
1688 				goto again;
1689 
1690 			pr_err("ALUA Target Port Group ID: %hu already"
1691 				" exists, ignoring request\n", tg_pt_gp_id);
1692 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1693 			return -EINVAL;
1694 		}
1695 	}
1696 
1697 	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1698 	tg_pt_gp->tg_pt_gp_valid_id = 1;
1699 	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1700 			&dev->t10_alua.tg_pt_gps_list);
1701 	dev->t10_alua.alua_tg_pt_gps_count++;
1702 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1703 
1704 	return 0;
1705 }
1706 
1707 void core_alua_free_tg_pt_gp(
1708 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1709 {
1710 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1711 	struct se_lun *lun, *next;
1712 
1713 	/*
1714 	 * Once we have reached this point, config_item_put() has already
1715 	 * been called from target_core_alua_drop_tg_pt_gp().
1716 	 *
1717 	 * Here we remove *tg_pt_gp from the global list so that
1718 	 * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1719 	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1720 	 */
1721 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1722 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1723 		list_del(&tg_pt_gp->tg_pt_gp_list);
1724 		dev->t10_alua.alua_tg_pt_gps_count--;
1725 	}
1726 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1727 
1728 	/*
1729 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1730 	 * core_alua_get_tg_pt_gp_by_name() in
1731 	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1732 	 * to be released with core_alua_put_tg_pt_gp_from_name().
1733 	 */
1734 	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1735 		cpu_relax();
1736 
1737 	/*
1738 	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1739 	 * struct se_port.
1740 	 */
1741 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1742 	list_for_each_entry_safe(lun, next,
1743 			&tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
1744 		list_del_init(&lun->lun_tg_pt_gp_link);
1745 		tg_pt_gp->tg_pt_gp_members--;
1746 
1747 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1748 		/*
1749 		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1750 		 * assume we want to re-associate a given tg_pt_gp_mem with
1751 		 * default_tg_pt_gp.
1752 		 */
1753 		spin_lock(&lun->lun_tg_pt_gp_lock);
1754 		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1755 			__target_attach_tg_pt_gp(lun,
1756 					dev->t10_alua.default_tg_pt_gp);
1757 		} else
1758 			rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
1759 		spin_unlock(&lun->lun_tg_pt_gp_lock);
1760 
1761 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1762 	}
1763 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1764 
1765 	synchronize_rcu();
1766 	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1767 }
1768 
1769 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1770 		struct se_device *dev, const char *name)
1771 {
1772 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1773 	struct config_item *ci;
1774 
1775 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1776 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1777 			tg_pt_gp_list) {
1778 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1779 			continue;
1780 		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1781 		if (!strcmp(config_item_name(ci), name)) {
1782 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1783 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1784 			return tg_pt_gp;
1785 		}
1786 	}
1787 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1788 
1789 	return NULL;
1790 }
1791 
1792 static void core_alua_put_tg_pt_gp_from_name(
1793 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1794 {
1795 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1796 
1797 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1798 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1799 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1800 }
1801 
1802 static void __target_attach_tg_pt_gp(struct se_lun *lun,
1803 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1804 {
1805 	struct se_dev_entry *se_deve;
1806 
1807 	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1808 
1809 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1810 	rcu_assign_pointer(lun->lun_tg_pt_gp, tg_pt_gp);
1811 	list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
1812 	tg_pt_gp->tg_pt_gp_members++;
1813 	spin_lock(&lun->lun_deve_lock);
1814 	list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
1815 		core_scsi3_ua_allocate(se_deve, 0x3f,
1816 				       ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
1817 	spin_unlock(&lun->lun_deve_lock);
1818 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1819 }
1820 
1821 void target_attach_tg_pt_gp(struct se_lun *lun,
1822 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1823 {
1824 	spin_lock(&lun->lun_tg_pt_gp_lock);
1825 	__target_attach_tg_pt_gp(lun, tg_pt_gp);
1826 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1827 	synchronize_rcu();
1828 }
1829 
1830 static void __target_detach_tg_pt_gp(struct se_lun *lun,
1831 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1832 {
1833 	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1834 
1835 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1836 	list_del_init(&lun->lun_tg_pt_gp_link);
1837 	tg_pt_gp->tg_pt_gp_members--;
1838 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1839 }
1840 
1841 void target_detach_tg_pt_gp(struct se_lun *lun)
1842 {
1843 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1844 
1845 	spin_lock(&lun->lun_tg_pt_gp_lock);
1846 	tg_pt_gp = rcu_dereference_check(lun->lun_tg_pt_gp,
1847 				lockdep_is_held(&lun->lun_tg_pt_gp_lock));
1848 	if (tg_pt_gp) {
1849 		__target_detach_tg_pt_gp(lun, tg_pt_gp);
1850 		rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
1851 	}
1852 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1853 	synchronize_rcu();
1854 }
1855 
1856 static void target_swap_tg_pt_gp(struct se_lun *lun,
1857 				 struct t10_alua_tg_pt_gp *old_tg_pt_gp,
1858 				 struct t10_alua_tg_pt_gp *new_tg_pt_gp)
1859 {
1860 	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1861 
1862 	if (old_tg_pt_gp)
1863 		__target_detach_tg_pt_gp(lun, old_tg_pt_gp);
1864 	__target_attach_tg_pt_gp(lun, new_tg_pt_gp);
1865 }
1866 
1867 ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
1868 {
1869 	struct config_item *tg_pt_ci;
1870 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1871 	ssize_t len = 0;
1872 
1873 	rcu_read_lock();
1874 	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
1875 	if (tg_pt_gp) {
1876 		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1877 		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1878 			" %hu\nTG Port Primary Access State: %s\nTG Port "
1879 			"Primary Access Status: %s\nTG Port Secondary Access"
1880 			" State: %s\nTG Port Secondary Access Status: %s\n",
1881 			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1882 			core_alua_dump_state(
1883 				tg_pt_gp->tg_pt_gp_alua_access_state),
1884 			core_alua_dump_status(
1885 				tg_pt_gp->tg_pt_gp_alua_access_status),
1886 			atomic_read(&lun->lun_tg_pt_secondary_offline) ?
1887 			"Offline" : "None",
1888 			core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
1889 	}
1890 	rcu_read_unlock();
1891 
1892 	return len;
1893 }
1894 
1895 ssize_t core_alua_store_tg_pt_gp_info(
1896 	struct se_lun *lun,
1897 	const char *page,
1898 	size_t count)
1899 {
1900 	struct se_portal_group *tpg = lun->lun_tpg;
1901 	/*
1902 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
1903 	 * reference to se_device->dev_group.
1904 	 */
1905 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
1906 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1907 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1908 	int move = 0;
1909 
1910 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
1911 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
1912 		return -ENODEV;
1913 
1914 	if (count > TG_PT_GROUP_NAME_BUF) {
1915 		pr_err("ALUA Target Port Group alias too large!\n");
1916 		return -EINVAL;
1917 	}
1918 	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1919 	memcpy(buf, page, count);
1920 	/*
1921 	 * Any ALUA target port group alias besides "NULL" means we will be
1922 	 * making a new group association.
1923 	 */
1924 	if (strcmp(strstrip(buf), "NULL")) {
1925 		/*
1926 		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1927 		 * struct t10_alua_tg_pt_gp.  This reference is released with
1928 		 * core_alua_put_tg_pt_gp_from_name() below.
1929 		 */
1930 		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1931 					strstrip(buf));
1932 		if (!tg_pt_gp_new)
1933 			return -ENODEV;
1934 	}
1935 
1936 	spin_lock(&lun->lun_tg_pt_gp_lock);
1937 	tg_pt_gp = rcu_dereference_check(lun->lun_tg_pt_gp,
1938 				lockdep_is_held(&lun->lun_tg_pt_gp_lock));
1939 	if (tg_pt_gp) {
1940 		/*
1941 		 * Clearing an existing tg_pt_gp association, and replacing
1942 		 * with the default_tg_pt_gp.
1943 		 */
1944 		if (!tg_pt_gp_new) {
1945 			pr_debug("Target_Core_ConfigFS: Moving"
1946 				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
1947 				" alua/%s, ID: %hu back to"
1948 				" default_tg_pt_gp\n",
1949 				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1950 				tpg->se_tpg_tfo->tpg_get_tag(tpg),
1951 				config_item_name(&lun->lun_group.cg_item),
1952 				config_item_name(
1953 					&tg_pt_gp->tg_pt_gp_group.cg_item),
1954 				tg_pt_gp->tg_pt_gp_id);
1955 
1956 			target_swap_tg_pt_gp(lun, tg_pt_gp,
1957 					dev->t10_alua.default_tg_pt_gp);
1958 			spin_unlock(&lun->lun_tg_pt_gp_lock);
1959 
1960 			goto sync_rcu;
1961 		}
1962 		move = 1;
1963 	}
1964 
1965 	target_swap_tg_pt_gp(lun, tg_pt_gp, tg_pt_gp_new);
1966 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1967 	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1968 		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
1969 		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1970 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
1971 		config_item_name(&lun->lun_group.cg_item),
1972 		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1973 		tg_pt_gp_new->tg_pt_gp_id);
1974 
1975 	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1976 sync_rcu:
1977 	synchronize_rcu();
1978 	return count;
1979 }
1980 
1981 ssize_t core_alua_show_access_type(
1982 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1983 	char *page)
1984 {
1985 	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
1986 	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
1987 		return sprintf(page, "Implicit and Explicit\n");
1988 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
1989 		return sprintf(page, "Implicit\n");
1990 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
1991 		return sprintf(page, "Explicit\n");
1992 	else
1993 		return sprintf(page, "None\n");
1994 }
1995 
1996 ssize_t core_alua_store_access_type(
1997 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1998 	const char *page,
1999 	size_t count)
2000 {
2001 	unsigned long tmp;
2002 	int ret;
2003 
2004 	ret = kstrtoul(page, 0, &tmp);
2005 	if (ret < 0) {
2006 		pr_err("Unable to extract alua_access_type\n");
2007 		return ret;
2008 	}
2009 	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
2010 		pr_err("Illegal value for alua_access_type:"
2011 				" %lu\n", tmp);
2012 		return -EINVAL;
2013 	}
2014 	if (tmp == 3)
2015 		tg_pt_gp->tg_pt_gp_alua_access_type =
2016 			TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
2017 	else if (tmp == 2)
2018 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
2019 	else if (tmp == 1)
2020 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
2021 	else
2022 		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
2023 
2024 	return count;
2025 }
2026 
2027 ssize_t core_alua_show_nonop_delay_msecs(
2028 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2029 	char *page)
2030 {
2031 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
2032 }
2033 
2034 ssize_t core_alua_store_nonop_delay_msecs(
2035 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2036 	const char *page,
2037 	size_t count)
2038 {
2039 	unsigned long tmp;
2040 	int ret;
2041 
2042 	ret = kstrtoul(page, 0, &tmp);
2043 	if (ret < 0) {
2044 		pr_err("Unable to extract nonop_delay_msecs\n");
2045 		return ret;
2046 	}
2047 	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
2048 		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
2049 			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
2050 			ALUA_MAX_NONOP_DELAY_MSECS);
2051 		return -EINVAL;
2052 	}
2053 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
2054 
2055 	return count;
2056 }
2057 
2058 ssize_t core_alua_show_trans_delay_msecs(
2059 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2060 	char *page)
2061 {
2062 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
2063 }
2064 
2065 ssize_t core_alua_store_trans_delay_msecs(
2066 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2067 	const char *page,
2068 	size_t count)
2069 {
2070 	unsigned long tmp;
2071 	int ret;
2072 
2073 	ret = kstrtoul(page, 0, &tmp);
2074 	if (ret < 0) {
2075 		pr_err("Unable to extract trans_delay_msecs\n");
2076 		return ret;
2077 	}
2078 	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
2079 		pr_err("Passed trans_delay_msecs: %lu, exceeds"
2080 			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
2081 			ALUA_MAX_TRANS_DELAY_MSECS);
2082 		return -EINVAL;
2083 	}
2084 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
2085 
2086 	return count;
2087 }
2088 
2089 ssize_t core_alua_show_implicit_trans_secs(
2090 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2091 	char *page)
2092 {
2093 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
2094 }
2095 
2096 ssize_t core_alua_store_implicit_trans_secs(
2097 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2098 	const char *page,
2099 	size_t count)
2100 {
2101 	unsigned long tmp;
2102 	int ret;
2103 
2104 	ret = kstrtoul(page, 0, &tmp);
2105 	if (ret < 0) {
2106 		pr_err("Unable to extract implicit_trans_secs\n");
2107 		return ret;
2108 	}
2109 	if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
2110 		pr_err("Passed implicit_trans_secs: %lu, exceeds"
2111 			" ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
2112 			ALUA_MAX_IMPLICIT_TRANS_SECS);
2113 		return  -EINVAL;
2114 	}
2115 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
2116 
2117 	return count;
2118 }
2119 
2120 ssize_t core_alua_show_preferred_bit(
2121 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2122 	char *page)
2123 {
2124 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
2125 }
2126 
2127 ssize_t core_alua_store_preferred_bit(
2128 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2129 	const char *page,
2130 	size_t count)
2131 {
2132 	unsigned long tmp;
2133 	int ret;
2134 
2135 	ret = kstrtoul(page, 0, &tmp);
2136 	if (ret < 0) {
2137 		pr_err("Unable to extract preferred ALUA value\n");
2138 		return ret;
2139 	}
2140 	if ((tmp != 0) && (tmp != 1)) {
2141 		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
2142 		return -EINVAL;
2143 	}
2144 	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
2145 
2146 	return count;
2147 }
2148 
2149 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
2150 {
2151 	return sprintf(page, "%d\n",
2152 		atomic_read(&lun->lun_tg_pt_secondary_offline));
2153 }
2154 
2155 ssize_t core_alua_store_offline_bit(
2156 	struct se_lun *lun,
2157 	const char *page,
2158 	size_t count)
2159 {
2160 	/*
2161 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
2162 	 * reference to se_device->dev_group.
2163 	 */
2164 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
2165 	unsigned long tmp;
2166 	int ret;
2167 
2168 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
2169 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
2170 		return -ENODEV;
2171 
2172 	ret = kstrtoul(page, 0, &tmp);
2173 	if (ret < 0) {
2174 		pr_err("Unable to extract alua_tg_pt_offline value\n");
2175 		return ret;
2176 	}
2177 	if ((tmp != 0) && (tmp != 1)) {
2178 		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
2179 				tmp);
2180 		return -EINVAL;
2181 	}
2182 
2183 	ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
2184 	if (ret < 0)
2185 		return -EINVAL;
2186 
2187 	return count;
2188 }
2189 
2190 ssize_t core_alua_show_secondary_status(
2191 	struct se_lun *lun,
2192 	char *page)
2193 {
2194 	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
2195 }
2196 
2197 ssize_t core_alua_store_secondary_status(
2198 	struct se_lun *lun,
2199 	const char *page,
2200 	size_t count)
2201 {
2202 	unsigned long tmp;
2203 	int ret;
2204 
2205 	ret = kstrtoul(page, 0, &tmp);
2206 	if (ret < 0) {
2207 		pr_err("Unable to extract alua_tg_pt_status\n");
2208 		return ret;
2209 	}
2210 	if ((tmp != ALUA_STATUS_NONE) &&
2211 	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
2212 	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
2213 		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2214 				tmp);
2215 		return -EINVAL;
2216 	}
2217 	lun->lun_tg_pt_secondary_stat = (int)tmp;
2218 
2219 	return count;
2220 }
2221 
2222 ssize_t core_alua_show_secondary_write_metadata(
2223 	struct se_lun *lun,
2224 	char *page)
2225 {
2226 	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
2227 }
2228 
2229 ssize_t core_alua_store_secondary_write_metadata(
2230 	struct se_lun *lun,
2231 	const char *page,
2232 	size_t count)
2233 {
2234 	unsigned long tmp;
2235 	int ret;
2236 
2237 	ret = kstrtoul(page, 0, &tmp);
2238 	if (ret < 0) {
2239 		pr_err("Unable to extract alua_tg_pt_write_md\n");
2240 		return ret;
2241 	}
2242 	if ((tmp != 0) && (tmp != 1)) {
2243 		pr_err("Illegal value for alua_tg_pt_write_md:"
2244 				" %lu\n", tmp);
2245 		return -EINVAL;
2246 	}
2247 	lun->lun_tg_pt_secondary_write_md = (int)tmp;
2248 
2249 	return count;
2250 }
2251 
2252 int core_setup_alua(struct se_device *dev)
2253 {
2254 	if (!(dev->transport_flags &
2255 	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
2256 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2257 		struct t10_alua_lu_gp_member *lu_gp_mem;
2258 
2259 		/*
2260 		 * Associate this struct se_device with the default ALUA
2261 		 * LUN Group.
2262 		 */
2263 		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2264 		if (IS_ERR(lu_gp_mem))
2265 			return PTR_ERR(lu_gp_mem);
2266 
2267 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2268 		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2269 				default_lu_gp);
2270 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2271 
2272 		pr_debug("%s: Adding to default ALUA LU Group:"
2273 			" core/alua/lu_gps/default_lu_gp\n",
2274 			dev->transport->name);
2275 	}
2276 
2277 	return 0;
2278 }
2279