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/export.h>
30 #include <linux/file.h>
31 #include <scsi/scsi_proto.h>
32 #include <asm/unaligned.h>
33 
34 #include <target/target_core_base.h>
35 #include <target/target_core_backend.h>
36 #include <target/target_core_fabric.h>
37 
38 #include "target_core_internal.h"
39 #include "target_core_alua.h"
40 #include "target_core_ua.h"
41 
42 static sense_reason_t core_alua_check_transition(int state, int valid,
43 						 int *primary);
44 static int core_alua_set_tg_pt_secondary_state(
45 		struct se_lun *lun, int explicit, int offline);
46 
47 static char *core_alua_dump_state(int state);
48 
49 static void __target_attach_tg_pt_gp(struct se_lun *lun,
50 		struct t10_alua_tg_pt_gp *tg_pt_gp);
51 
52 static u16 alua_lu_gps_counter;
53 static u32 alua_lu_gps_count;
54 
55 static DEFINE_SPINLOCK(lu_gps_lock);
56 static LIST_HEAD(lu_gps_list);
57 
58 struct t10_alua_lu_gp *default_lu_gp;
59 
60 /*
61  * REPORT REFERRALS
62  *
63  * See sbc3r35 section 5.23
64  */
65 sense_reason_t
66 target_emulate_report_referrals(struct se_cmd *cmd)
67 {
68 	struct se_device *dev = cmd->se_dev;
69 	struct t10_alua_lba_map *map;
70 	struct t10_alua_lba_map_member *map_mem;
71 	unsigned char *buf;
72 	u32 rd_len = 0, off;
73 
74 	if (cmd->data_length < 4) {
75 		pr_warn("REPORT REFERRALS allocation length %u too"
76 			" small\n", cmd->data_length);
77 		return TCM_INVALID_CDB_FIELD;
78 	}
79 
80 	buf = transport_kmap_data_sg(cmd);
81 	if (!buf)
82 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
83 
84 	off = 4;
85 	spin_lock(&dev->t10_alua.lba_map_lock);
86 	if (list_empty(&dev->t10_alua.lba_map_list)) {
87 		spin_unlock(&dev->t10_alua.lba_map_lock);
88 		transport_kunmap_data_sg(cmd);
89 
90 		return TCM_UNSUPPORTED_SCSI_OPCODE;
91 	}
92 
93 	list_for_each_entry(map, &dev->t10_alua.lba_map_list,
94 			    lba_map_list) {
95 		int desc_num = off + 3;
96 		int pg_num;
97 
98 		off += 4;
99 		if (cmd->data_length > off)
100 			put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
101 		off += 8;
102 		if (cmd->data_length > off)
103 			put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
104 		off += 8;
105 		rd_len += 20;
106 		pg_num = 0;
107 		list_for_each_entry(map_mem, &map->lba_map_mem_list,
108 				    lba_map_mem_list) {
109 			int alua_state = map_mem->lba_map_mem_alua_state;
110 			int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;
111 
112 			if (cmd->data_length > off)
113 				buf[off] = alua_state & 0x0f;
114 			off += 2;
115 			if (cmd->data_length > off)
116 				buf[off] = (alua_pg_id >> 8) & 0xff;
117 			off++;
118 			if (cmd->data_length > off)
119 				buf[off] = (alua_pg_id & 0xff);
120 			off++;
121 			rd_len += 4;
122 			pg_num++;
123 		}
124 		if (cmd->data_length > desc_num)
125 			buf[desc_num] = pg_num;
126 	}
127 	spin_unlock(&dev->t10_alua.lba_map_lock);
128 
129 	/*
130 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
131 	 */
132 	put_unaligned_be16(rd_len, &buf[2]);
133 
134 	transport_kunmap_data_sg(cmd);
135 
136 	target_complete_cmd(cmd, GOOD);
137 	return 0;
138 }
139 
140 /*
141  * REPORT_TARGET_PORT_GROUPS
142  *
143  * See spc4r17 section 6.27
144  */
145 sense_reason_t
146 target_emulate_report_target_port_groups(struct se_cmd *cmd)
147 {
148 	struct se_device *dev = cmd->se_dev;
149 	struct t10_alua_tg_pt_gp *tg_pt_gp;
150 	struct se_lun *lun;
151 	unsigned char *buf;
152 	u32 rd_len = 0, off;
153 	int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
154 
155 	/*
156 	 * Skip over RESERVED area to first Target port group descriptor
157 	 * depending on the PARAMETER DATA FORMAT type..
158 	 */
159 	if (ext_hdr != 0)
160 		off = 8;
161 	else
162 		off = 4;
163 
164 	if (cmd->data_length < off) {
165 		pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
166 			" small for %s header\n", cmd->data_length,
167 			(ext_hdr) ? "extended" : "normal");
168 		return TCM_INVALID_CDB_FIELD;
169 	}
170 	buf = transport_kmap_data_sg(cmd);
171 	if (!buf)
172 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
173 
174 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
175 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
176 			tg_pt_gp_list) {
177 		/*
178 		 * Check if the Target port group and Target port descriptor list
179 		 * based on tg_pt_gp_members count will fit into the response payload.
180 		 * Otherwise, bump rd_len to let the initiator know we have exceeded
181 		 * the allocation length and the response is truncated.
182 		 */
183 		if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
184 		     cmd->data_length) {
185 			rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
186 			continue;
187 		}
188 		/*
189 		 * PREF: Preferred target port bit, determine if this
190 		 * bit should be set for port group.
191 		 */
192 		if (tg_pt_gp->tg_pt_gp_pref)
193 			buf[off] = 0x80;
194 		/*
195 		 * Set the ASYMMETRIC ACCESS State
196 		 */
197 		buf[off++] |= (atomic_read(
198 			&tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
199 		/*
200 		 * Set supported ASYMMETRIC ACCESS State bits
201 		 */
202 		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
203 		/*
204 		 * TARGET PORT GROUP
205 		 */
206 		buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
207 		buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
208 
209 		off++; /* Skip over Reserved */
210 		/*
211 		 * STATUS CODE
212 		 */
213 		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
214 		/*
215 		 * Vendor Specific field
216 		 */
217 		buf[off++] = 0x00;
218 		/*
219 		 * TARGET PORT COUNT
220 		 */
221 		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
222 		rd_len += 8;
223 
224 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
225 		list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
226 				lun_tg_pt_gp_link) {
227 			/*
228 			 * Start Target Port descriptor format
229 			 *
230 			 * See spc4r17 section 6.2.7 Table 247
231 			 */
232 			off += 2; /* Skip over Obsolete */
233 			/*
234 			 * Set RELATIVE TARGET PORT IDENTIFIER
235 			 */
236 			buf[off++] = ((lun->lun_rtpi >> 8) & 0xff);
237 			buf[off++] = (lun->lun_rtpi & 0xff);
238 			rd_len += 4;
239 		}
240 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
241 	}
242 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
243 	/*
244 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
245 	 */
246 	put_unaligned_be32(rd_len, &buf[0]);
247 
248 	/*
249 	 * Fill in the Extended header parameter data format if requested
250 	 */
251 	if (ext_hdr != 0) {
252 		buf[4] = 0x10;
253 		/*
254 		 * Set the implicit transition time (in seconds) for the application
255 		 * client to use as a base for it's transition timeout value.
256 		 *
257 		 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
258 		 * this CDB was received upon to determine this value individually
259 		 * for ALUA target port group.
260 		 */
261 		spin_lock(&cmd->se_lun->lun_tg_pt_gp_lock);
262 		tg_pt_gp = cmd->se_lun->lun_tg_pt_gp;
263 		if (tg_pt_gp)
264 			buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
265 		spin_unlock(&cmd->se_lun->lun_tg_pt_gp_lock);
266 	}
267 	transport_kunmap_data_sg(cmd);
268 
269 	target_complete_cmd(cmd, GOOD);
270 	return 0;
271 }
272 
273 /*
274  * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
275  *
276  * See spc4r17 section 6.35
277  */
278 sense_reason_t
279 target_emulate_set_target_port_groups(struct se_cmd *cmd)
280 {
281 	struct se_device *dev = cmd->se_dev;
282 	struct se_lun *l_lun = cmd->se_lun;
283 	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
284 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
285 	unsigned char *buf;
286 	unsigned char *ptr;
287 	sense_reason_t rc = TCM_NO_SENSE;
288 	u32 len = 4; /* Skip over RESERVED area in header */
289 	int alua_access_state, primary = 0, valid_states;
290 	u16 tg_pt_id, rtpi;
291 
292 	if (cmd->data_length < 4) {
293 		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
294 			" small\n", cmd->data_length);
295 		return TCM_INVALID_PARAMETER_LIST;
296 	}
297 
298 	buf = transport_kmap_data_sg(cmd);
299 	if (!buf)
300 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
301 
302 	/*
303 	 * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
304 	 * for the local tg_pt_gp.
305 	 */
306 	spin_lock(&l_lun->lun_tg_pt_gp_lock);
307 	l_tg_pt_gp = l_lun->lun_tg_pt_gp;
308 	if (!l_tg_pt_gp) {
309 		spin_unlock(&l_lun->lun_tg_pt_gp_lock);
310 		pr_err("Unable to access l_lun->tg_pt_gp\n");
311 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
312 		goto out;
313 	}
314 
315 	if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
316 		spin_unlock(&l_lun->lun_tg_pt_gp_lock);
317 		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
318 				" while TPGS_EXPLICIT_ALUA is disabled\n");
319 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
320 		goto out;
321 	}
322 	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
323 	spin_unlock(&l_lun->lun_tg_pt_gp_lock);
324 
325 	ptr = &buf[4]; /* Skip over RESERVED area in header */
326 
327 	while (len < cmd->data_length) {
328 		bool found = false;
329 		alua_access_state = (ptr[0] & 0x0f);
330 		/*
331 		 * Check the received ALUA access state, and determine if
332 		 * the state is a primary or secondary target port asymmetric
333 		 * access state.
334 		 */
335 		rc = core_alua_check_transition(alua_access_state,
336 						valid_states, &primary);
337 		if (rc) {
338 			/*
339 			 * If the SET TARGET PORT GROUPS attempts to establish
340 			 * an invalid combination of target port asymmetric
341 			 * access states or attempts to establish an
342 			 * unsupported target port asymmetric access state,
343 			 * then the command shall be terminated with CHECK
344 			 * CONDITION status, with the sense key set to ILLEGAL
345 			 * REQUEST, and the additional sense code set to INVALID
346 			 * FIELD IN PARAMETER LIST.
347 			 */
348 			goto out;
349 		}
350 
351 		/*
352 		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
353 		 * specifies a primary target port asymmetric access state,
354 		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
355 		 * a primary target port group for which the primary target
356 		 * port asymmetric access state shall be changed. If the
357 		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
358 		 * port asymmetric access state, then the TARGET PORT GROUP OR
359 		 * TARGET PORT field specifies the relative target port
360 		 * identifier (see 3.1.120) of the target port for which the
361 		 * secondary target port asymmetric access state shall be
362 		 * changed.
363 		 */
364 		if (primary) {
365 			tg_pt_id = get_unaligned_be16(ptr + 2);
366 			/*
367 			 * Locate the matching target port group ID from
368 			 * the global tg_pt_gp list
369 			 */
370 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
371 			list_for_each_entry(tg_pt_gp,
372 					&dev->t10_alua.tg_pt_gps_list,
373 					tg_pt_gp_list) {
374 				if (!tg_pt_gp->tg_pt_gp_valid_id)
375 					continue;
376 
377 				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
378 					continue;
379 
380 				atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
381 
382 				spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
383 
384 				if (!core_alua_do_port_transition(tg_pt_gp,
385 						dev, l_lun, nacl,
386 						alua_access_state, 1))
387 					found = true;
388 
389 				spin_lock(&dev->t10_alua.tg_pt_gps_lock);
390 				atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
391 				break;
392 			}
393 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
394 		} else {
395 			struct se_lun *lun;
396 
397 			/*
398 			 * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
399 			 * the Target Port in question for the the incoming
400 			 * SET_TARGET_PORT_GROUPS op.
401 			 */
402 			rtpi = get_unaligned_be16(ptr + 2);
403 			/*
404 			 * Locate the matching relative target port identifier
405 			 * for the struct se_device storage object.
406 			 */
407 			spin_lock(&dev->se_port_lock);
408 			list_for_each_entry(lun, &dev->dev_sep_list,
409 							lun_dev_link) {
410 				if (lun->lun_rtpi != rtpi)
411 					continue;
412 
413 				// XXX: racy unlock
414 				spin_unlock(&dev->se_port_lock);
415 
416 				if (!core_alua_set_tg_pt_secondary_state(
417 						lun, 1, 1))
418 					found = true;
419 
420 				spin_lock(&dev->se_port_lock);
421 				break;
422 			}
423 			spin_unlock(&dev->se_port_lock);
424 		}
425 
426 		if (!found) {
427 			rc = TCM_INVALID_PARAMETER_LIST;
428 			goto out;
429 		}
430 
431 		ptr += 4;
432 		len += 4;
433 	}
434 
435 out:
436 	transport_kunmap_data_sg(cmd);
437 	if (!rc)
438 		target_complete_cmd(cmd, GOOD);
439 	return rc;
440 }
441 
442 static inline void set_ascq(struct se_cmd *cmd, u8 alua_ascq)
443 {
444 	/*
445 	 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
446 	 * The ALUA additional sense code qualifier (ASCQ) is determined
447 	 * by the ALUA primary or secondary access state..
448 	 */
449 	pr_debug("[%s]: ALUA TG Port not available, "
450 		"SenseKey: NOT_READY, ASC/ASCQ: "
451 		"0x04/0x%02x\n",
452 		cmd->se_tfo->get_fabric_name(), alua_ascq);
453 
454 	cmd->scsi_asc = 0x04;
455 	cmd->scsi_ascq = alua_ascq;
456 }
457 
458 static inline void core_alua_state_nonoptimized(
459 	struct se_cmd *cmd,
460 	unsigned char *cdb,
461 	int nonop_delay_msecs)
462 {
463 	/*
464 	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
465 	 * later to determine if processing of this cmd needs to be
466 	 * temporarily delayed for the Active/NonOptimized primary access state.
467 	 */
468 	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
469 	cmd->alua_nonop_delay = nonop_delay_msecs;
470 }
471 
472 static inline int core_alua_state_lba_dependent(
473 	struct se_cmd *cmd,
474 	struct t10_alua_tg_pt_gp *tg_pt_gp)
475 {
476 	struct se_device *dev = cmd->se_dev;
477 	u64 segment_size, segment_mult, sectors, lba;
478 
479 	/* Only need to check for cdb actually containing LBAs */
480 	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
481 		return 0;
482 
483 	spin_lock(&dev->t10_alua.lba_map_lock);
484 	segment_size = dev->t10_alua.lba_map_segment_size;
485 	segment_mult = dev->t10_alua.lba_map_segment_multiplier;
486 	sectors = cmd->data_length / dev->dev_attrib.block_size;
487 
488 	lba = cmd->t_task_lba;
489 	while (lba < cmd->t_task_lba + sectors) {
490 		struct t10_alua_lba_map *cur_map = NULL, *map;
491 		struct t10_alua_lba_map_member *map_mem;
492 
493 		list_for_each_entry(map, &dev->t10_alua.lba_map_list,
494 				    lba_map_list) {
495 			u64 start_lba, last_lba;
496 			u64 first_lba = map->lba_map_first_lba;
497 
498 			if (segment_mult) {
499 				u64 tmp = lba;
500 				start_lba = do_div(tmp, segment_size * segment_mult);
501 
502 				last_lba = first_lba + segment_size - 1;
503 				if (start_lba >= first_lba &&
504 				    start_lba <= last_lba) {
505 					lba += segment_size;
506 					cur_map = map;
507 					break;
508 				}
509 			} else {
510 				last_lba = map->lba_map_last_lba;
511 				if (lba >= first_lba && lba <= last_lba) {
512 					lba = last_lba + 1;
513 					cur_map = map;
514 					break;
515 				}
516 			}
517 		}
518 		if (!cur_map) {
519 			spin_unlock(&dev->t10_alua.lba_map_lock);
520 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
521 			return 1;
522 		}
523 		list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
524 				    lba_map_mem_list) {
525 			if (map_mem->lba_map_mem_alua_pg_id !=
526 			    tg_pt_gp->tg_pt_gp_id)
527 				continue;
528 			switch(map_mem->lba_map_mem_alua_state) {
529 			case ALUA_ACCESS_STATE_STANDBY:
530 				spin_unlock(&dev->t10_alua.lba_map_lock);
531 				set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
532 				return 1;
533 			case ALUA_ACCESS_STATE_UNAVAILABLE:
534 				spin_unlock(&dev->t10_alua.lba_map_lock);
535 				set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
536 				return 1;
537 			default:
538 				break;
539 			}
540 		}
541 	}
542 	spin_unlock(&dev->t10_alua.lba_map_lock);
543 	return 0;
544 }
545 
546 static inline int core_alua_state_standby(
547 	struct se_cmd *cmd,
548 	unsigned char *cdb)
549 {
550 	/*
551 	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
552 	 * spc4r17 section 5.9.2.4.4
553 	 */
554 	switch (cdb[0]) {
555 	case INQUIRY:
556 	case LOG_SELECT:
557 	case LOG_SENSE:
558 	case MODE_SELECT:
559 	case MODE_SENSE:
560 	case REPORT_LUNS:
561 	case RECEIVE_DIAGNOSTIC:
562 	case SEND_DIAGNOSTIC:
563 	case READ_CAPACITY:
564 		return 0;
565 	case SERVICE_ACTION_IN_16:
566 		switch (cdb[1] & 0x1f) {
567 		case SAI_READ_CAPACITY_16:
568 			return 0;
569 		default:
570 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
571 			return 1;
572 		}
573 	case MAINTENANCE_IN:
574 		switch (cdb[1] & 0x1f) {
575 		case MI_REPORT_TARGET_PGS:
576 			return 0;
577 		default:
578 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
579 			return 1;
580 		}
581 	case MAINTENANCE_OUT:
582 		switch (cdb[1]) {
583 		case MO_SET_TARGET_PGS:
584 			return 0;
585 		default:
586 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
587 			return 1;
588 		}
589 	case REQUEST_SENSE:
590 	case PERSISTENT_RESERVE_IN:
591 	case PERSISTENT_RESERVE_OUT:
592 	case READ_BUFFER:
593 	case WRITE_BUFFER:
594 		return 0;
595 	default:
596 		set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_STANDBY);
597 		return 1;
598 	}
599 
600 	return 0;
601 }
602 
603 static inline int core_alua_state_unavailable(
604 	struct se_cmd *cmd,
605 	unsigned char *cdb)
606 {
607 	/*
608 	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
609 	 * spc4r17 section 5.9.2.4.5
610 	 */
611 	switch (cdb[0]) {
612 	case INQUIRY:
613 	case REPORT_LUNS:
614 		return 0;
615 	case MAINTENANCE_IN:
616 		switch (cdb[1] & 0x1f) {
617 		case MI_REPORT_TARGET_PGS:
618 			return 0;
619 		default:
620 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
621 			return 1;
622 		}
623 	case MAINTENANCE_OUT:
624 		switch (cdb[1]) {
625 		case MO_SET_TARGET_PGS:
626 			return 0;
627 		default:
628 			set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
629 			return 1;
630 		}
631 	case REQUEST_SENSE:
632 	case READ_BUFFER:
633 	case WRITE_BUFFER:
634 		return 0;
635 	default:
636 		set_ascq(cmd, ASCQ_04H_ALUA_TG_PT_UNAVAILABLE);
637 		return 1;
638 	}
639 
640 	return 0;
641 }
642 
643 static inline int core_alua_state_transition(
644 	struct se_cmd *cmd,
645 	unsigned char *cdb)
646 {
647 	/*
648 	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
649 	 * spc4r17 section 5.9.2.5
650 	 */
651 	switch (cdb[0]) {
652 	case INQUIRY:
653 	case REPORT_LUNS:
654 		return 0;
655 	case MAINTENANCE_IN:
656 		switch (cdb[1] & 0x1f) {
657 		case MI_REPORT_TARGET_PGS:
658 			return 0;
659 		default:
660 			set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
661 			return 1;
662 		}
663 	case REQUEST_SENSE:
664 	case READ_BUFFER:
665 	case WRITE_BUFFER:
666 		return 0;
667 	default:
668 		set_ascq(cmd, ASCQ_04H_ALUA_STATE_TRANSITION);
669 		return 1;
670 	}
671 
672 	return 0;
673 }
674 
675 /*
676  * return 1: Is used to signal LUN not accessible, and check condition/not ready
677  * return 0: Used to signal success
678  * return -1: Used to signal failure, and invalid cdb field
679  */
680 sense_reason_t
681 target_alua_state_check(struct se_cmd *cmd)
682 {
683 	struct se_device *dev = cmd->se_dev;
684 	unsigned char *cdb = cmd->t_task_cdb;
685 	struct se_lun *lun = cmd->se_lun;
686 	struct t10_alua_tg_pt_gp *tg_pt_gp;
687 	int out_alua_state, nonop_delay_msecs;
688 
689 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
690 		return 0;
691 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
692 		return 0;
693 
694 	/*
695 	 * First, check for a struct se_port specific secondary ALUA target port
696 	 * access state: OFFLINE
697 	 */
698 	if (atomic_read(&lun->lun_tg_pt_secondary_offline)) {
699 		pr_debug("ALUA: Got secondary offline status for local"
700 				" target port\n");
701 		set_ascq(cmd, ASCQ_04H_ALUA_OFFLINE);
702 		return TCM_CHECK_CONDITION_NOT_READY;
703 	}
704 
705 	if (!lun->lun_tg_pt_gp)
706 		return 0;
707 
708 	spin_lock(&lun->lun_tg_pt_gp_lock);
709 	tg_pt_gp = lun->lun_tg_pt_gp;
710 	out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
711 	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
712 
713 	// XXX: keeps using tg_pt_gp witout reference after unlock
714 	spin_unlock(&lun->lun_tg_pt_gp_lock);
715 	/*
716 	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
717 	 * statement so the compiler knows explicitly to check this case first.
718 	 * For the Optimized ALUA access state case, we want to process the
719 	 * incoming fabric cmd ASAP..
720 	 */
721 	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
722 		return 0;
723 
724 	switch (out_alua_state) {
725 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
726 		core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
727 		break;
728 	case ALUA_ACCESS_STATE_STANDBY:
729 		if (core_alua_state_standby(cmd, cdb))
730 			return TCM_CHECK_CONDITION_NOT_READY;
731 		break;
732 	case ALUA_ACCESS_STATE_UNAVAILABLE:
733 		if (core_alua_state_unavailable(cmd, cdb))
734 			return TCM_CHECK_CONDITION_NOT_READY;
735 		break;
736 	case ALUA_ACCESS_STATE_TRANSITION:
737 		if (core_alua_state_transition(cmd, cdb))
738 			return TCM_CHECK_CONDITION_NOT_READY;
739 		break;
740 	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
741 		if (core_alua_state_lba_dependent(cmd, tg_pt_gp))
742 			return TCM_CHECK_CONDITION_NOT_READY;
743 		break;
744 	/*
745 	 * OFFLINE is a secondary ALUA target port group access state, that is
746 	 * handled above with struct se_lun->lun_tg_pt_secondary_offline=1
747 	 */
748 	case ALUA_ACCESS_STATE_OFFLINE:
749 	default:
750 		pr_err("Unknown ALUA access state: 0x%02x\n",
751 				out_alua_state);
752 		return TCM_INVALID_CDB_FIELD;
753 	}
754 
755 	return 0;
756 }
757 
758 /*
759  * Check implicit and explicit ALUA state change request.
760  */
761 static sense_reason_t
762 core_alua_check_transition(int state, int valid, int *primary)
763 {
764 	/*
765 	 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
766 	 * defined as primary target port asymmetric access states.
767 	 */
768 	switch (state) {
769 	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
770 		if (!(valid & ALUA_AO_SUP))
771 			goto not_supported;
772 		*primary = 1;
773 		break;
774 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
775 		if (!(valid & ALUA_AN_SUP))
776 			goto not_supported;
777 		*primary = 1;
778 		break;
779 	case ALUA_ACCESS_STATE_STANDBY:
780 		if (!(valid & ALUA_S_SUP))
781 			goto not_supported;
782 		*primary = 1;
783 		break;
784 	case ALUA_ACCESS_STATE_UNAVAILABLE:
785 		if (!(valid & ALUA_U_SUP))
786 			goto not_supported;
787 		*primary = 1;
788 		break;
789 	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
790 		if (!(valid & ALUA_LBD_SUP))
791 			goto not_supported;
792 		*primary = 1;
793 		break;
794 	case ALUA_ACCESS_STATE_OFFLINE:
795 		/*
796 		 * OFFLINE state is defined as a secondary target port
797 		 * asymmetric access state.
798 		 */
799 		if (!(valid & ALUA_O_SUP))
800 			goto not_supported;
801 		*primary = 0;
802 		break;
803 	case ALUA_ACCESS_STATE_TRANSITION:
804 		/*
805 		 * Transitioning is set internally, and
806 		 * cannot be selected manually.
807 		 */
808 		goto not_supported;
809 	default:
810 		pr_err("Unknown ALUA access state: 0x%02x\n", state);
811 		return TCM_INVALID_PARAMETER_LIST;
812 	}
813 
814 	return 0;
815 
816 not_supported:
817 	pr_err("ALUA access state %s not supported",
818 	       core_alua_dump_state(state));
819 	return TCM_INVALID_PARAMETER_LIST;
820 }
821 
822 static char *core_alua_dump_state(int state)
823 {
824 	switch (state) {
825 	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
826 		return "Active/Optimized";
827 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
828 		return "Active/NonOptimized";
829 	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
830 		return "LBA Dependent";
831 	case ALUA_ACCESS_STATE_STANDBY:
832 		return "Standby";
833 	case ALUA_ACCESS_STATE_UNAVAILABLE:
834 		return "Unavailable";
835 	case ALUA_ACCESS_STATE_OFFLINE:
836 		return "Offline";
837 	case ALUA_ACCESS_STATE_TRANSITION:
838 		return "Transitioning";
839 	default:
840 		return "Unknown";
841 	}
842 
843 	return NULL;
844 }
845 
846 char *core_alua_dump_status(int status)
847 {
848 	switch (status) {
849 	case ALUA_STATUS_NONE:
850 		return "None";
851 	case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
852 		return "Altered by Explicit STPG";
853 	case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
854 		return "Altered by Implicit ALUA";
855 	default:
856 		return "Unknown";
857 	}
858 
859 	return NULL;
860 }
861 
862 /*
863  * Used by fabric modules to determine when we need to delay processing
864  * for the Active/NonOptimized paths..
865  */
866 int core_alua_check_nonop_delay(
867 	struct se_cmd *cmd)
868 {
869 	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
870 		return 0;
871 	if (in_interrupt())
872 		return 0;
873 	/*
874 	 * The ALUA Active/NonOptimized access state delay can be disabled
875 	 * in via configfs with a value of zero
876 	 */
877 	if (!cmd->alua_nonop_delay)
878 		return 0;
879 	/*
880 	 * struct se_cmd->alua_nonop_delay gets set by a target port group
881 	 * defined interval in core_alua_state_nonoptimized()
882 	 */
883 	msleep_interruptible(cmd->alua_nonop_delay);
884 	return 0;
885 }
886 EXPORT_SYMBOL(core_alua_check_nonop_delay);
887 
888 static int core_alua_write_tpg_metadata(
889 	const char *path,
890 	unsigned char *md_buf,
891 	u32 md_buf_len)
892 {
893 	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
894 	int ret;
895 
896 	if (IS_ERR(file)) {
897 		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
898 		return -ENODEV;
899 	}
900 	ret = kernel_write(file, md_buf, md_buf_len, 0);
901 	if (ret < 0)
902 		pr_err("Error writing ALUA metadata file: %s\n", path);
903 	fput(file);
904 	return (ret < 0) ? -EIO : 0;
905 }
906 
907 /*
908  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
909  */
910 static int core_alua_update_tpg_primary_metadata(
911 	struct t10_alua_tg_pt_gp *tg_pt_gp)
912 {
913 	unsigned char *md_buf;
914 	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
915 	char path[ALUA_METADATA_PATH_LEN];
916 	int len, rc;
917 
918 	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
919 	if (!md_buf) {
920 		pr_err("Unable to allocate buf for ALUA metadata\n");
921 		return -ENOMEM;
922 	}
923 
924 	memset(path, 0, ALUA_METADATA_PATH_LEN);
925 
926 	len = snprintf(md_buf, ALUA_MD_BUF_LEN,
927 			"tg_pt_gp_id=%hu\n"
928 			"alua_access_state=0x%02x\n"
929 			"alua_access_status=0x%02x\n",
930 			tg_pt_gp->tg_pt_gp_id,
931 			tg_pt_gp->tg_pt_gp_alua_pending_state,
932 			tg_pt_gp->tg_pt_gp_alua_access_status);
933 
934 	snprintf(path, ALUA_METADATA_PATH_LEN,
935 		"/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
936 		config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
937 
938 	rc = core_alua_write_tpg_metadata(path, md_buf, len);
939 	kfree(md_buf);
940 	return rc;
941 }
942 
943 static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
944 {
945 	struct se_dev_entry *se_deve;
946 	struct se_lun *lun;
947 	struct se_lun_acl *lacl;
948 
949 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
950 	list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
951 				lun_tg_pt_gp_link) {
952 		/*
953 		 * After an implicit target port asymmetric access state
954 		 * change, a device server shall establish a unit attention
955 		 * condition for the initiator port associated with every I_T
956 		 * nexus with the additional sense code set to ASYMMETRIC
957 		 * ACCESS STATE CHANGED.
958 		 *
959 		 * After an explicit target port asymmetric access state
960 		 * change, a device server shall establish a unit attention
961 		 * condition with the additional sense code set to ASYMMETRIC
962 		 * ACCESS STATE CHANGED for the initiator port associated with
963 		 * every I_T nexus other than the I_T nexus on which the SET
964 		 * TARGET PORT GROUPS command
965 		 */
966 		if (!percpu_ref_tryget_live(&lun->lun_ref))
967 			continue;
968 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
969 
970 		spin_lock(&lun->lun_deve_lock);
971 		list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
972 			lacl = rcu_dereference_check(se_deve->se_lun_acl,
973 					lockdep_is_held(&lun->lun_deve_lock));
974 
975 			/*
976 			 * spc4r37 p.242:
977 			 * After an explicit target port asymmetric access
978 			 * state change, a device server shall establish a
979 			 * unit attention condition with the additional sense
980 			 * code set to ASYMMETRIC ACCESS STATE CHANGED for
981 			 * the initiator port associated with every I_T nexus
982 			 * other than the I_T nexus on which the SET TARGET
983 			 * PORT GROUPS command was received.
984 			 */
985 			if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
986 			     ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
987 			   (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
988 			    (tg_pt_gp->tg_pt_gp_alua_lun == lun))
989 				continue;
990 
991 			/*
992 			 * se_deve->se_lun_acl pointer may be NULL for a
993 			 * entry created without explicit Node+MappedLUN ACLs
994 			 */
995 			if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
996 			    (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
997 				continue;
998 
999 			core_scsi3_ua_allocate(se_deve, 0x2A,
1000 				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
1001 		}
1002 		spin_unlock(&lun->lun_deve_lock);
1003 
1004 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1005 		percpu_ref_put(&lun->lun_ref);
1006 	}
1007 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1008 }
1009 
1010 static void core_alua_do_transition_tg_pt_work(struct work_struct *work)
1011 {
1012 	struct t10_alua_tg_pt_gp *tg_pt_gp = container_of(work,
1013 		struct t10_alua_tg_pt_gp, tg_pt_gp_transition_work.work);
1014 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1015 	bool explicit = (tg_pt_gp->tg_pt_gp_alua_access_status ==
1016 			 ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG);
1017 
1018 	/*
1019 	 * Update the ALUA metadata buf that has been allocated in
1020 	 * core_alua_do_port_transition(), this metadata will be written
1021 	 * to struct file.
1022 	 *
1023 	 * Note that there is the case where we do not want to update the
1024 	 * metadata when the saved metadata is being parsed in userspace
1025 	 * when setting the existing port access state and access status.
1026 	 *
1027 	 * Also note that the failure to write out the ALUA metadata to
1028 	 * struct file does NOT affect the actual ALUA transition.
1029 	 */
1030 	if (tg_pt_gp->tg_pt_gp_write_metadata) {
1031 		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
1032 		core_alua_update_tpg_primary_metadata(tg_pt_gp);
1033 		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
1034 	}
1035 	/*
1036 	 * Set the current primary ALUA access state to the requested new state
1037 	 */
1038 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1039 		   tg_pt_gp->tg_pt_gp_alua_pending_state);
1040 
1041 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1042 		" from primary access state %s to %s\n", (explicit) ? "explicit" :
1043 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1044 		tg_pt_gp->tg_pt_gp_id,
1045 		core_alua_dump_state(tg_pt_gp->tg_pt_gp_alua_previous_state),
1046 		core_alua_dump_state(tg_pt_gp->tg_pt_gp_alua_pending_state));
1047 
1048 	core_alua_queue_state_change_ua(tg_pt_gp);
1049 
1050 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1051 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1052 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1053 
1054 	if (tg_pt_gp->tg_pt_gp_transition_complete)
1055 		complete(tg_pt_gp->tg_pt_gp_transition_complete);
1056 }
1057 
1058 static int core_alua_do_transition_tg_pt(
1059 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1060 	int new_state,
1061 	int explicit)
1062 {
1063 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1064 	DECLARE_COMPLETION_ONSTACK(wait);
1065 
1066 	/* Nothing to be done here */
1067 	if (atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) == new_state)
1068 		return 0;
1069 
1070 	if (new_state == ALUA_ACCESS_STATE_TRANSITION)
1071 		return -EAGAIN;
1072 
1073 	/*
1074 	 * Flush any pending transitions
1075 	 */
1076 	if (!explicit && tg_pt_gp->tg_pt_gp_implicit_trans_secs &&
1077 	    atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) ==
1078 	    ALUA_ACCESS_STATE_TRANSITION) {
1079 		/* Just in case */
1080 		tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;
1081 		tg_pt_gp->tg_pt_gp_transition_complete = &wait;
1082 		flush_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work);
1083 		wait_for_completion(&wait);
1084 		tg_pt_gp->tg_pt_gp_transition_complete = NULL;
1085 		return 0;
1086 	}
1087 
1088 	/*
1089 	 * Save the old primary ALUA access state, and set the current state
1090 	 * to ALUA_ACCESS_STATE_TRANSITION.
1091 	 */
1092 	tg_pt_gp->tg_pt_gp_alua_previous_state =
1093 		atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
1094 	tg_pt_gp->tg_pt_gp_alua_pending_state = new_state;
1095 
1096 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1097 			ALUA_ACCESS_STATE_TRANSITION);
1098 	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
1099 				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1100 				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1101 
1102 	core_alua_queue_state_change_ua(tg_pt_gp);
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 	if (!explicit && tg_pt_gp->tg_pt_gp_implicit_trans_secs) {
1118 		unsigned long transition_tmo;
1119 
1120 		transition_tmo = tg_pt_gp->tg_pt_gp_implicit_trans_secs * HZ;
1121 		queue_delayed_work(tg_pt_gp->tg_pt_gp_dev->tmr_wq,
1122 				   &tg_pt_gp->tg_pt_gp_transition_work,
1123 				   transition_tmo);
1124 	} else {
1125 		tg_pt_gp->tg_pt_gp_transition_complete = &wait;
1126 		queue_delayed_work(tg_pt_gp->tg_pt_gp_dev->tmr_wq,
1127 				   &tg_pt_gp->tg_pt_gp_transition_work, 0);
1128 		wait_for_completion(&wait);
1129 		tg_pt_gp->tg_pt_gp_transition_complete = NULL;
1130 	}
1131 
1132 	return 0;
1133 }
1134 
1135 int core_alua_do_port_transition(
1136 	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
1137 	struct se_device *l_dev,
1138 	struct se_lun *l_lun,
1139 	struct se_node_acl *l_nacl,
1140 	int new_state,
1141 	int explicit)
1142 {
1143 	struct se_device *dev;
1144 	struct t10_alua_lu_gp *lu_gp;
1145 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
1146 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1147 	int primary, valid_states, rc = 0;
1148 
1149 	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
1150 	if (core_alua_check_transition(new_state, valid_states, &primary) != 0)
1151 		return -EINVAL;
1152 
1153 	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
1154 	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
1155 	lu_gp = local_lu_gp_mem->lu_gp;
1156 	atomic_inc(&lu_gp->lu_gp_ref_cnt);
1157 	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
1158 	/*
1159 	 * For storage objects that are members of the 'default_lu_gp',
1160 	 * we only do transition on the passed *l_tp_pt_gp, and not
1161 	 * on all of the matching target port groups IDs in default_lu_gp.
1162 	 */
1163 	if (!lu_gp->lu_gp_id) {
1164 		/*
1165 		 * core_alua_do_transition_tg_pt() will always return
1166 		 * success.
1167 		 */
1168 		l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1169 		l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1170 		rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
1171 						   new_state, explicit);
1172 		atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1173 		return rc;
1174 	}
1175 	/*
1176 	 * For all other LU groups aside from 'default_lu_gp', walk all of
1177 	 * the associated storage objects looking for a matching target port
1178 	 * group ID from the local target port group.
1179 	 */
1180 	spin_lock(&lu_gp->lu_gp_lock);
1181 	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
1182 				lu_gp_mem_list) {
1183 
1184 		dev = lu_gp_mem->lu_gp_mem_dev;
1185 		atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1186 		spin_unlock(&lu_gp->lu_gp_lock);
1187 
1188 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1189 		list_for_each_entry(tg_pt_gp,
1190 				&dev->t10_alua.tg_pt_gps_list,
1191 				tg_pt_gp_list) {
1192 
1193 			if (!tg_pt_gp->tg_pt_gp_valid_id)
1194 				continue;
1195 			/*
1196 			 * If the target behavior port asymmetric access state
1197 			 * is changed for any target port group accessible via
1198 			 * a logical unit within a LU group, the target port
1199 			 * behavior group asymmetric access states for the same
1200 			 * target port group accessible via other logical units
1201 			 * in that LU group will also change.
1202 			 */
1203 			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
1204 				continue;
1205 
1206 			if (l_tg_pt_gp == tg_pt_gp) {
1207 				tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1208 				tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1209 			} else {
1210 				tg_pt_gp->tg_pt_gp_alua_lun = NULL;
1211 				tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
1212 			}
1213 			atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1214 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1215 			/*
1216 			 * core_alua_do_transition_tg_pt() will always return
1217 			 * success.
1218 			 */
1219 			rc = core_alua_do_transition_tg_pt(tg_pt_gp,
1220 					new_state, explicit);
1221 
1222 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1223 			atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1224 			if (rc)
1225 				break;
1226 		}
1227 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1228 
1229 		spin_lock(&lu_gp->lu_gp_lock);
1230 		atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1231 	}
1232 	spin_unlock(&lu_gp->lu_gp_lock);
1233 
1234 	if (!rc) {
1235 		pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1236 			 " Group IDs: %hu %s transition to primary state: %s\n",
1237 			 config_item_name(&lu_gp->lu_gp_group.cg_item),
1238 			 l_tg_pt_gp->tg_pt_gp_id,
1239 			 (explicit) ? "explicit" : "implicit",
1240 			 core_alua_dump_state(new_state));
1241 	}
1242 
1243 	atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1244 	return rc;
1245 }
1246 
1247 static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
1248 {
1249 	struct se_portal_group *se_tpg = lun->lun_tpg;
1250 	unsigned char *md_buf;
1251 	char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1252 	int len, rc;
1253 
1254 	mutex_lock(&lun->lun_tg_pt_md_mutex);
1255 
1256 	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
1257 	if (!md_buf) {
1258 		pr_err("Unable to allocate buf for ALUA metadata\n");
1259 		rc = -ENOMEM;
1260 		goto out_unlock;
1261 	}
1262 
1263 	memset(path, 0, ALUA_METADATA_PATH_LEN);
1264 	memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1265 
1266 	len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1267 			se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1268 
1269 	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1270 		snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1271 				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1272 
1273 	len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
1274 			"alua_tg_pt_status=0x%02x\n",
1275 			atomic_read(&lun->lun_tg_pt_secondary_offline),
1276 			lun->lun_tg_pt_secondary_stat);
1277 
1278 	snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%llu",
1279 			se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1280 			lun->unpacked_lun);
1281 
1282 	rc = core_alua_write_tpg_metadata(path, md_buf, len);
1283 	kfree(md_buf);
1284 
1285 out_unlock:
1286 	mutex_unlock(&lun->lun_tg_pt_md_mutex);
1287 	return rc;
1288 }
1289 
1290 static int core_alua_set_tg_pt_secondary_state(
1291 	struct se_lun *lun,
1292 	int explicit,
1293 	int offline)
1294 {
1295 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1296 	int trans_delay_msecs;
1297 
1298 	spin_lock(&lun->lun_tg_pt_gp_lock);
1299 	tg_pt_gp = lun->lun_tg_pt_gp;
1300 	if (!tg_pt_gp) {
1301 		spin_unlock(&lun->lun_tg_pt_gp_lock);
1302 		pr_err("Unable to complete secondary state"
1303 				" transition\n");
1304 		return -EINVAL;
1305 	}
1306 	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1307 	/*
1308 	 * Set the secondary ALUA target port access state to OFFLINE
1309 	 * or release the previously secondary state for struct se_lun
1310 	 */
1311 	if (offline)
1312 		atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
1313 	else
1314 		atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
1315 
1316 	lun->lun_tg_pt_secondary_stat = (explicit) ?
1317 			ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1318 			ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1319 
1320 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1321 		" to secondary access state: %s\n", (explicit) ? "explicit" :
1322 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1323 		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1324 
1325 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1326 	/*
1327 	 * Do the optional transition delay after we set the secondary
1328 	 * ALUA access state.
1329 	 */
1330 	if (trans_delay_msecs != 0)
1331 		msleep_interruptible(trans_delay_msecs);
1332 	/*
1333 	 * See if we need to update the ALUA fabric port metadata for
1334 	 * secondary state and status
1335 	 */
1336 	if (lun->lun_tg_pt_secondary_write_md)
1337 		core_alua_update_tpg_secondary_metadata(lun);
1338 
1339 	return 0;
1340 }
1341 
1342 struct t10_alua_lba_map *
1343 core_alua_allocate_lba_map(struct list_head *list,
1344 			   u64 first_lba, u64 last_lba)
1345 {
1346 	struct t10_alua_lba_map *lba_map;
1347 
1348 	lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
1349 	if (!lba_map) {
1350 		pr_err("Unable to allocate struct t10_alua_lba_map\n");
1351 		return ERR_PTR(-ENOMEM);
1352 	}
1353 	INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
1354 	lba_map->lba_map_first_lba = first_lba;
1355 	lba_map->lba_map_last_lba = last_lba;
1356 
1357 	list_add_tail(&lba_map->lba_map_list, list);
1358 	return lba_map;
1359 }
1360 
1361 int
1362 core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
1363 			       int pg_id, int state)
1364 {
1365 	struct t10_alua_lba_map_member *lba_map_mem;
1366 
1367 	list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
1368 			    lba_map_mem_list) {
1369 		if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
1370 			pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
1371 			return -EINVAL;
1372 		}
1373 	}
1374 
1375 	lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
1376 	if (!lba_map_mem) {
1377 		pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
1378 		return -ENOMEM;
1379 	}
1380 	lba_map_mem->lba_map_mem_alua_state = state;
1381 	lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
1382 
1383 	list_add_tail(&lba_map_mem->lba_map_mem_list,
1384 		      &lba_map->lba_map_mem_list);
1385 	return 0;
1386 }
1387 
1388 void
1389 core_alua_free_lba_map(struct list_head *lba_list)
1390 {
1391 	struct t10_alua_lba_map *lba_map, *lba_map_tmp;
1392 	struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
1393 
1394 	list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
1395 				 lba_map_list) {
1396 		list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
1397 					 &lba_map->lba_map_mem_list,
1398 					 lba_map_mem_list) {
1399 			list_del(&lba_map_mem->lba_map_mem_list);
1400 			kmem_cache_free(t10_alua_lba_map_mem_cache,
1401 					lba_map_mem);
1402 		}
1403 		list_del(&lba_map->lba_map_list);
1404 		kmem_cache_free(t10_alua_lba_map_cache, lba_map);
1405 	}
1406 }
1407 
1408 void
1409 core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
1410 		      int segment_size, int segment_mult)
1411 {
1412 	struct list_head old_lba_map_list;
1413 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1414 	int activate = 0, supported;
1415 
1416 	INIT_LIST_HEAD(&old_lba_map_list);
1417 	spin_lock(&dev->t10_alua.lba_map_lock);
1418 	dev->t10_alua.lba_map_segment_size = segment_size;
1419 	dev->t10_alua.lba_map_segment_multiplier = segment_mult;
1420 	list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
1421 	if (lba_map_list) {
1422 		list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
1423 		activate = 1;
1424 	}
1425 	spin_unlock(&dev->t10_alua.lba_map_lock);
1426 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1427 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1428 			    tg_pt_gp_list) {
1429 
1430 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1431 			continue;
1432 		supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
1433 		if (activate)
1434 			supported |= ALUA_LBD_SUP;
1435 		else
1436 			supported &= ~ALUA_LBD_SUP;
1437 		tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
1438 	}
1439 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1440 	core_alua_free_lba_map(&old_lba_map_list);
1441 }
1442 
1443 struct t10_alua_lu_gp *
1444 core_alua_allocate_lu_gp(const char *name, int def_group)
1445 {
1446 	struct t10_alua_lu_gp *lu_gp;
1447 
1448 	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1449 	if (!lu_gp) {
1450 		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1451 		return ERR_PTR(-ENOMEM);
1452 	}
1453 	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1454 	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1455 	spin_lock_init(&lu_gp->lu_gp_lock);
1456 	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1457 
1458 	if (def_group) {
1459 		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1460 		lu_gp->lu_gp_valid_id = 1;
1461 		alua_lu_gps_count++;
1462 	}
1463 
1464 	return lu_gp;
1465 }
1466 
1467 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1468 {
1469 	struct t10_alua_lu_gp *lu_gp_tmp;
1470 	u16 lu_gp_id_tmp;
1471 	/*
1472 	 * The lu_gp->lu_gp_id may only be set once..
1473 	 */
1474 	if (lu_gp->lu_gp_valid_id) {
1475 		pr_warn("ALUA LU Group already has a valid ID,"
1476 			" ignoring request\n");
1477 		return -EINVAL;
1478 	}
1479 
1480 	spin_lock(&lu_gps_lock);
1481 	if (alua_lu_gps_count == 0x0000ffff) {
1482 		pr_err("Maximum ALUA alua_lu_gps_count:"
1483 				" 0x0000ffff reached\n");
1484 		spin_unlock(&lu_gps_lock);
1485 		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1486 		return -ENOSPC;
1487 	}
1488 again:
1489 	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1490 				alua_lu_gps_counter++;
1491 
1492 	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1493 		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1494 			if (!lu_gp_id)
1495 				goto again;
1496 
1497 			pr_warn("ALUA Logical Unit Group ID: %hu"
1498 				" already exists, ignoring request\n",
1499 				lu_gp_id);
1500 			spin_unlock(&lu_gps_lock);
1501 			return -EINVAL;
1502 		}
1503 	}
1504 
1505 	lu_gp->lu_gp_id = lu_gp_id_tmp;
1506 	lu_gp->lu_gp_valid_id = 1;
1507 	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1508 	alua_lu_gps_count++;
1509 	spin_unlock(&lu_gps_lock);
1510 
1511 	return 0;
1512 }
1513 
1514 static struct t10_alua_lu_gp_member *
1515 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1516 {
1517 	struct t10_alua_lu_gp_member *lu_gp_mem;
1518 
1519 	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1520 	if (!lu_gp_mem) {
1521 		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1522 		return ERR_PTR(-ENOMEM);
1523 	}
1524 	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1525 	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1526 	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1527 
1528 	lu_gp_mem->lu_gp_mem_dev = dev;
1529 	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1530 
1531 	return lu_gp_mem;
1532 }
1533 
1534 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1535 {
1536 	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1537 	/*
1538 	 * Once we have reached this point, config_item_put() has
1539 	 * already been called from target_core_alua_drop_lu_gp().
1540 	 *
1541 	 * Here, we remove the *lu_gp from the global list so that
1542 	 * no associations can be made while we are releasing
1543 	 * struct t10_alua_lu_gp.
1544 	 */
1545 	spin_lock(&lu_gps_lock);
1546 	list_del(&lu_gp->lu_gp_node);
1547 	alua_lu_gps_count--;
1548 	spin_unlock(&lu_gps_lock);
1549 	/*
1550 	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1551 	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1552 	 * released with core_alua_put_lu_gp_from_name()
1553 	 */
1554 	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1555 		cpu_relax();
1556 	/*
1557 	 * Release reference to struct t10_alua_lu_gp * from all associated
1558 	 * struct se_device.
1559 	 */
1560 	spin_lock(&lu_gp->lu_gp_lock);
1561 	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1562 				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1563 		if (lu_gp_mem->lu_gp_assoc) {
1564 			list_del(&lu_gp_mem->lu_gp_mem_list);
1565 			lu_gp->lu_gp_members--;
1566 			lu_gp_mem->lu_gp_assoc = 0;
1567 		}
1568 		spin_unlock(&lu_gp->lu_gp_lock);
1569 		/*
1570 		 *
1571 		 * lu_gp_mem is associated with a single
1572 		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1573 		 * struct se_device is released via core_alua_free_lu_gp_mem().
1574 		 *
1575 		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1576 		 * we want to re-associate a given lu_gp_mem with default_lu_gp.
1577 		 */
1578 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1579 		if (lu_gp != default_lu_gp)
1580 			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1581 					default_lu_gp);
1582 		else
1583 			lu_gp_mem->lu_gp = NULL;
1584 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1585 
1586 		spin_lock(&lu_gp->lu_gp_lock);
1587 	}
1588 	spin_unlock(&lu_gp->lu_gp_lock);
1589 
1590 	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1591 }
1592 
1593 void core_alua_free_lu_gp_mem(struct se_device *dev)
1594 {
1595 	struct t10_alua_lu_gp *lu_gp;
1596 	struct t10_alua_lu_gp_member *lu_gp_mem;
1597 
1598 	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1599 	if (!lu_gp_mem)
1600 		return;
1601 
1602 	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1603 		cpu_relax();
1604 
1605 	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1606 	lu_gp = lu_gp_mem->lu_gp;
1607 	if (lu_gp) {
1608 		spin_lock(&lu_gp->lu_gp_lock);
1609 		if (lu_gp_mem->lu_gp_assoc) {
1610 			list_del(&lu_gp_mem->lu_gp_mem_list);
1611 			lu_gp->lu_gp_members--;
1612 			lu_gp_mem->lu_gp_assoc = 0;
1613 		}
1614 		spin_unlock(&lu_gp->lu_gp_lock);
1615 		lu_gp_mem->lu_gp = NULL;
1616 	}
1617 	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1618 
1619 	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1620 }
1621 
1622 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1623 {
1624 	struct t10_alua_lu_gp *lu_gp;
1625 	struct config_item *ci;
1626 
1627 	spin_lock(&lu_gps_lock);
1628 	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1629 		if (!lu_gp->lu_gp_valid_id)
1630 			continue;
1631 		ci = &lu_gp->lu_gp_group.cg_item;
1632 		if (!strcmp(config_item_name(ci), name)) {
1633 			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1634 			spin_unlock(&lu_gps_lock);
1635 			return lu_gp;
1636 		}
1637 	}
1638 	spin_unlock(&lu_gps_lock);
1639 
1640 	return NULL;
1641 }
1642 
1643 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1644 {
1645 	spin_lock(&lu_gps_lock);
1646 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1647 	spin_unlock(&lu_gps_lock);
1648 }
1649 
1650 /*
1651  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1652  */
1653 void __core_alua_attach_lu_gp_mem(
1654 	struct t10_alua_lu_gp_member *lu_gp_mem,
1655 	struct t10_alua_lu_gp *lu_gp)
1656 {
1657 	spin_lock(&lu_gp->lu_gp_lock);
1658 	lu_gp_mem->lu_gp = lu_gp;
1659 	lu_gp_mem->lu_gp_assoc = 1;
1660 	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1661 	lu_gp->lu_gp_members++;
1662 	spin_unlock(&lu_gp->lu_gp_lock);
1663 }
1664 
1665 /*
1666  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1667  */
1668 void __core_alua_drop_lu_gp_mem(
1669 	struct t10_alua_lu_gp_member *lu_gp_mem,
1670 	struct t10_alua_lu_gp *lu_gp)
1671 {
1672 	spin_lock(&lu_gp->lu_gp_lock);
1673 	list_del(&lu_gp_mem->lu_gp_mem_list);
1674 	lu_gp_mem->lu_gp = NULL;
1675 	lu_gp_mem->lu_gp_assoc = 0;
1676 	lu_gp->lu_gp_members--;
1677 	spin_unlock(&lu_gp->lu_gp_lock);
1678 }
1679 
1680 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1681 		const char *name, int def_group)
1682 {
1683 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1684 
1685 	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1686 	if (!tg_pt_gp) {
1687 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1688 		return NULL;
1689 	}
1690 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1691 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
1692 	mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1693 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1694 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1695 	INIT_DELAYED_WORK(&tg_pt_gp->tg_pt_gp_transition_work,
1696 			  core_alua_do_transition_tg_pt_work);
1697 	tg_pt_gp->tg_pt_gp_dev = dev;
1698 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1699 		ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED);
1700 	/*
1701 	 * Enable both explicit and implicit ALUA support by default
1702 	 */
1703 	tg_pt_gp->tg_pt_gp_alua_access_type =
1704 			TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1705 	/*
1706 	 * Set the default Active/NonOptimized Delay in milliseconds
1707 	 */
1708 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1709 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1710 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1711 
1712 	/*
1713 	 * Enable all supported states
1714 	 */
1715 	tg_pt_gp->tg_pt_gp_alua_supported_states =
1716 	    ALUA_T_SUP | ALUA_O_SUP |
1717 	    ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1718 
1719 	if (def_group) {
1720 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1721 		tg_pt_gp->tg_pt_gp_id =
1722 				dev->t10_alua.alua_tg_pt_gps_counter++;
1723 		tg_pt_gp->tg_pt_gp_valid_id = 1;
1724 		dev->t10_alua.alua_tg_pt_gps_count++;
1725 		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1726 			      &dev->t10_alua.tg_pt_gps_list);
1727 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1728 	}
1729 
1730 	return tg_pt_gp;
1731 }
1732 
1733 int core_alua_set_tg_pt_gp_id(
1734 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1735 	u16 tg_pt_gp_id)
1736 {
1737 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1738 	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1739 	u16 tg_pt_gp_id_tmp;
1740 
1741 	/*
1742 	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1743 	 */
1744 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1745 		pr_warn("ALUA TG PT Group already has a valid ID,"
1746 			" ignoring request\n");
1747 		return -EINVAL;
1748 	}
1749 
1750 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1751 	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1752 		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1753 			" 0x0000ffff reached\n");
1754 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1755 		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1756 		return -ENOSPC;
1757 	}
1758 again:
1759 	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1760 			dev->t10_alua.alua_tg_pt_gps_counter++;
1761 
1762 	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1763 			tg_pt_gp_list) {
1764 		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1765 			if (!tg_pt_gp_id)
1766 				goto again;
1767 
1768 			pr_err("ALUA Target Port Group ID: %hu already"
1769 				" exists, ignoring request\n", tg_pt_gp_id);
1770 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1771 			return -EINVAL;
1772 		}
1773 	}
1774 
1775 	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1776 	tg_pt_gp->tg_pt_gp_valid_id = 1;
1777 	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1778 			&dev->t10_alua.tg_pt_gps_list);
1779 	dev->t10_alua.alua_tg_pt_gps_count++;
1780 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1781 
1782 	return 0;
1783 }
1784 
1785 void core_alua_free_tg_pt_gp(
1786 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1787 {
1788 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1789 	struct se_lun *lun, *next;
1790 
1791 	/*
1792 	 * Once we have reached this point, config_item_put() has already
1793 	 * been called from target_core_alua_drop_tg_pt_gp().
1794 	 *
1795 	 * Here we remove *tg_pt_gp from the global list so that
1796 	 * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1797 	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1798 	 */
1799 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1800 	list_del(&tg_pt_gp->tg_pt_gp_list);
1801 	dev->t10_alua.alua_tg_pt_gps_counter--;
1802 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1803 
1804 	flush_delayed_work(&tg_pt_gp->tg_pt_gp_transition_work);
1805 
1806 	/*
1807 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1808 	 * core_alua_get_tg_pt_gp_by_name() in
1809 	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1810 	 * to be released with core_alua_put_tg_pt_gp_from_name().
1811 	 */
1812 	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1813 		cpu_relax();
1814 
1815 	/*
1816 	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1817 	 * struct se_port.
1818 	 */
1819 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1820 	list_for_each_entry_safe(lun, next,
1821 			&tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
1822 		list_del_init(&lun->lun_tg_pt_gp_link);
1823 		tg_pt_gp->tg_pt_gp_members--;
1824 
1825 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1826 		/*
1827 		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1828 		 * assume we want to re-associate a given tg_pt_gp_mem with
1829 		 * default_tg_pt_gp.
1830 		 */
1831 		spin_lock(&lun->lun_tg_pt_gp_lock);
1832 		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1833 			__target_attach_tg_pt_gp(lun,
1834 					dev->t10_alua.default_tg_pt_gp);
1835 		} else
1836 			lun->lun_tg_pt_gp = NULL;
1837 		spin_unlock(&lun->lun_tg_pt_gp_lock);
1838 
1839 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1840 	}
1841 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1842 
1843 	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1844 }
1845 
1846 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1847 		struct se_device *dev, const char *name)
1848 {
1849 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1850 	struct config_item *ci;
1851 
1852 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1853 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1854 			tg_pt_gp_list) {
1855 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1856 			continue;
1857 		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1858 		if (!strcmp(config_item_name(ci), name)) {
1859 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1860 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1861 			return tg_pt_gp;
1862 		}
1863 	}
1864 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1865 
1866 	return NULL;
1867 }
1868 
1869 static void core_alua_put_tg_pt_gp_from_name(
1870 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1871 {
1872 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1873 
1874 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1875 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1876 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1877 }
1878 
1879 static void __target_attach_tg_pt_gp(struct se_lun *lun,
1880 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1881 {
1882 	struct se_dev_entry *se_deve;
1883 
1884 	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1885 
1886 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1887 	lun->lun_tg_pt_gp = tg_pt_gp;
1888 	list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
1889 	tg_pt_gp->tg_pt_gp_members++;
1890 	spin_lock(&lun->lun_deve_lock);
1891 	list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
1892 		core_scsi3_ua_allocate(se_deve, 0x3f,
1893 				       ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
1894 	spin_unlock(&lun->lun_deve_lock);
1895 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1896 }
1897 
1898 void target_attach_tg_pt_gp(struct se_lun *lun,
1899 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1900 {
1901 	spin_lock(&lun->lun_tg_pt_gp_lock);
1902 	__target_attach_tg_pt_gp(lun, tg_pt_gp);
1903 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1904 }
1905 
1906 static void __target_detach_tg_pt_gp(struct se_lun *lun,
1907 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1908 {
1909 	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1910 
1911 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1912 	list_del_init(&lun->lun_tg_pt_gp_link);
1913 	tg_pt_gp->tg_pt_gp_members--;
1914 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1915 
1916 	lun->lun_tg_pt_gp = NULL;
1917 }
1918 
1919 void target_detach_tg_pt_gp(struct se_lun *lun)
1920 {
1921 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1922 
1923 	spin_lock(&lun->lun_tg_pt_gp_lock);
1924 	tg_pt_gp = lun->lun_tg_pt_gp;
1925 	if (tg_pt_gp)
1926 		__target_detach_tg_pt_gp(lun, tg_pt_gp);
1927 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1928 }
1929 
1930 ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
1931 {
1932 	struct config_item *tg_pt_ci;
1933 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1934 	ssize_t len = 0;
1935 
1936 	spin_lock(&lun->lun_tg_pt_gp_lock);
1937 	tg_pt_gp = lun->lun_tg_pt_gp;
1938 	if (tg_pt_gp) {
1939 		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1940 		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1941 			" %hu\nTG Port Primary Access State: %s\nTG Port "
1942 			"Primary Access Status: %s\nTG Port Secondary Access"
1943 			" State: %s\nTG Port Secondary Access Status: %s\n",
1944 			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1945 			core_alua_dump_state(atomic_read(
1946 					&tg_pt_gp->tg_pt_gp_alua_access_state)),
1947 			core_alua_dump_status(
1948 				tg_pt_gp->tg_pt_gp_alua_access_status),
1949 			atomic_read(&lun->lun_tg_pt_secondary_offline) ?
1950 			"Offline" : "None",
1951 			core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
1952 	}
1953 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1954 
1955 	return len;
1956 }
1957 
1958 ssize_t core_alua_store_tg_pt_gp_info(
1959 	struct se_lun *lun,
1960 	const char *page,
1961 	size_t count)
1962 {
1963 	struct se_portal_group *tpg = lun->lun_tpg;
1964 	/*
1965 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
1966 	 * reference to se_device->dev_group.
1967 	 */
1968 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
1969 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1970 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1971 	int move = 0;
1972 
1973 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH ||
1974 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
1975 		return -ENODEV;
1976 
1977 	if (count > TG_PT_GROUP_NAME_BUF) {
1978 		pr_err("ALUA Target Port Group alias too large!\n");
1979 		return -EINVAL;
1980 	}
1981 	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1982 	memcpy(buf, page, count);
1983 	/*
1984 	 * Any ALUA target port group alias besides "NULL" means we will be
1985 	 * making a new group association.
1986 	 */
1987 	if (strcmp(strstrip(buf), "NULL")) {
1988 		/*
1989 		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1990 		 * struct t10_alua_tg_pt_gp.  This reference is released with
1991 		 * core_alua_put_tg_pt_gp_from_name() below.
1992 		 */
1993 		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1994 					strstrip(buf));
1995 		if (!tg_pt_gp_new)
1996 			return -ENODEV;
1997 	}
1998 
1999 	spin_lock(&lun->lun_tg_pt_gp_lock);
2000 	tg_pt_gp = lun->lun_tg_pt_gp;
2001 	if (tg_pt_gp) {
2002 		/*
2003 		 * Clearing an existing tg_pt_gp association, and replacing
2004 		 * with the default_tg_pt_gp.
2005 		 */
2006 		if (!tg_pt_gp_new) {
2007 			pr_debug("Target_Core_ConfigFS: Moving"
2008 				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
2009 				" alua/%s, ID: %hu back to"
2010 				" default_tg_pt_gp\n",
2011 				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
2012 				tpg->se_tpg_tfo->tpg_get_tag(tpg),
2013 				config_item_name(&lun->lun_group.cg_item),
2014 				config_item_name(
2015 					&tg_pt_gp->tg_pt_gp_group.cg_item),
2016 				tg_pt_gp->tg_pt_gp_id);
2017 
2018 			__target_detach_tg_pt_gp(lun, tg_pt_gp);
2019 			__target_attach_tg_pt_gp(lun,
2020 					dev->t10_alua.default_tg_pt_gp);
2021 			spin_unlock(&lun->lun_tg_pt_gp_lock);
2022 
2023 			return count;
2024 		}
2025 		__target_detach_tg_pt_gp(lun, tg_pt_gp);
2026 		move = 1;
2027 	}
2028 
2029 	__target_attach_tg_pt_gp(lun, tg_pt_gp_new);
2030 	spin_unlock(&lun->lun_tg_pt_gp_lock);
2031 	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
2032 		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
2033 		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
2034 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
2035 		config_item_name(&lun->lun_group.cg_item),
2036 		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
2037 		tg_pt_gp_new->tg_pt_gp_id);
2038 
2039 	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
2040 	return count;
2041 }
2042 
2043 ssize_t core_alua_show_access_type(
2044 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2045 	char *page)
2046 {
2047 	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
2048 	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
2049 		return sprintf(page, "Implicit and Explicit\n");
2050 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
2051 		return sprintf(page, "Implicit\n");
2052 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
2053 		return sprintf(page, "Explicit\n");
2054 	else
2055 		return sprintf(page, "None\n");
2056 }
2057 
2058 ssize_t core_alua_store_access_type(
2059 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2060 	const char *page,
2061 	size_t count)
2062 {
2063 	unsigned long tmp;
2064 	int ret;
2065 
2066 	ret = kstrtoul(page, 0, &tmp);
2067 	if (ret < 0) {
2068 		pr_err("Unable to extract alua_access_type\n");
2069 		return ret;
2070 	}
2071 	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
2072 		pr_err("Illegal value for alua_access_type:"
2073 				" %lu\n", tmp);
2074 		return -EINVAL;
2075 	}
2076 	if (tmp == 3)
2077 		tg_pt_gp->tg_pt_gp_alua_access_type =
2078 			TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
2079 	else if (tmp == 2)
2080 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
2081 	else if (tmp == 1)
2082 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
2083 	else
2084 		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
2085 
2086 	return count;
2087 }
2088 
2089 ssize_t core_alua_show_nonop_delay_msecs(
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_nonop_delay_msecs);
2094 }
2095 
2096 ssize_t core_alua_store_nonop_delay_msecs(
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 nonop_delay_msecs\n");
2107 		return ret;
2108 	}
2109 	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
2110 		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
2111 			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
2112 			ALUA_MAX_NONOP_DELAY_MSECS);
2113 		return -EINVAL;
2114 	}
2115 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
2116 
2117 	return count;
2118 }
2119 
2120 ssize_t core_alua_show_trans_delay_msecs(
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_trans_delay_msecs);
2125 }
2126 
2127 ssize_t core_alua_store_trans_delay_msecs(
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 trans_delay_msecs\n");
2138 		return ret;
2139 	}
2140 	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
2141 		pr_err("Passed trans_delay_msecs: %lu, exceeds"
2142 			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
2143 			ALUA_MAX_TRANS_DELAY_MSECS);
2144 		return -EINVAL;
2145 	}
2146 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
2147 
2148 	return count;
2149 }
2150 
2151 ssize_t core_alua_show_implicit_trans_secs(
2152 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2153 	char *page)
2154 {
2155 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
2156 }
2157 
2158 ssize_t core_alua_store_implicit_trans_secs(
2159 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2160 	const char *page,
2161 	size_t count)
2162 {
2163 	unsigned long tmp;
2164 	int ret;
2165 
2166 	ret = kstrtoul(page, 0, &tmp);
2167 	if (ret < 0) {
2168 		pr_err("Unable to extract implicit_trans_secs\n");
2169 		return ret;
2170 	}
2171 	if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
2172 		pr_err("Passed implicit_trans_secs: %lu, exceeds"
2173 			" ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
2174 			ALUA_MAX_IMPLICIT_TRANS_SECS);
2175 		return  -EINVAL;
2176 	}
2177 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
2178 
2179 	return count;
2180 }
2181 
2182 ssize_t core_alua_show_preferred_bit(
2183 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2184 	char *page)
2185 {
2186 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
2187 }
2188 
2189 ssize_t core_alua_store_preferred_bit(
2190 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2191 	const char *page,
2192 	size_t count)
2193 {
2194 	unsigned long tmp;
2195 	int ret;
2196 
2197 	ret = kstrtoul(page, 0, &tmp);
2198 	if (ret < 0) {
2199 		pr_err("Unable to extract preferred ALUA value\n");
2200 		return ret;
2201 	}
2202 	if ((tmp != 0) && (tmp != 1)) {
2203 		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
2204 		return -EINVAL;
2205 	}
2206 	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
2207 
2208 	return count;
2209 }
2210 
2211 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
2212 {
2213 	return sprintf(page, "%d\n",
2214 		atomic_read(&lun->lun_tg_pt_secondary_offline));
2215 }
2216 
2217 ssize_t core_alua_store_offline_bit(
2218 	struct se_lun *lun,
2219 	const char *page,
2220 	size_t count)
2221 {
2222 	/*
2223 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
2224 	 * reference to se_device->dev_group.
2225 	 */
2226 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
2227 	unsigned long tmp;
2228 	int ret;
2229 
2230 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH ||
2231 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
2232 		return -ENODEV;
2233 
2234 	ret = kstrtoul(page, 0, &tmp);
2235 	if (ret < 0) {
2236 		pr_err("Unable to extract alua_tg_pt_offline value\n");
2237 		return ret;
2238 	}
2239 	if ((tmp != 0) && (tmp != 1)) {
2240 		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
2241 				tmp);
2242 		return -EINVAL;
2243 	}
2244 
2245 	ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
2246 	if (ret < 0)
2247 		return -EINVAL;
2248 
2249 	return count;
2250 }
2251 
2252 ssize_t core_alua_show_secondary_status(
2253 	struct se_lun *lun,
2254 	char *page)
2255 {
2256 	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
2257 }
2258 
2259 ssize_t core_alua_store_secondary_status(
2260 	struct se_lun *lun,
2261 	const char *page,
2262 	size_t count)
2263 {
2264 	unsigned long tmp;
2265 	int ret;
2266 
2267 	ret = kstrtoul(page, 0, &tmp);
2268 	if (ret < 0) {
2269 		pr_err("Unable to extract alua_tg_pt_status\n");
2270 		return ret;
2271 	}
2272 	if ((tmp != ALUA_STATUS_NONE) &&
2273 	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
2274 	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
2275 		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2276 				tmp);
2277 		return -EINVAL;
2278 	}
2279 	lun->lun_tg_pt_secondary_stat = (int)tmp;
2280 
2281 	return count;
2282 }
2283 
2284 ssize_t core_alua_show_secondary_write_metadata(
2285 	struct se_lun *lun,
2286 	char *page)
2287 {
2288 	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
2289 }
2290 
2291 ssize_t core_alua_store_secondary_write_metadata(
2292 	struct se_lun *lun,
2293 	const char *page,
2294 	size_t count)
2295 {
2296 	unsigned long tmp;
2297 	int ret;
2298 
2299 	ret = kstrtoul(page, 0, &tmp);
2300 	if (ret < 0) {
2301 		pr_err("Unable to extract alua_tg_pt_write_md\n");
2302 		return ret;
2303 	}
2304 	if ((tmp != 0) && (tmp != 1)) {
2305 		pr_err("Illegal value for alua_tg_pt_write_md:"
2306 				" %lu\n", tmp);
2307 		return -EINVAL;
2308 	}
2309 	lun->lun_tg_pt_secondary_write_md = (int)tmp;
2310 
2311 	return count;
2312 }
2313 
2314 int core_setup_alua(struct se_device *dev)
2315 {
2316 	if (!(dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH) &&
2317 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2318 		struct t10_alua_lu_gp_member *lu_gp_mem;
2319 
2320 		/*
2321 		 * Associate this struct se_device with the default ALUA
2322 		 * LUN Group.
2323 		 */
2324 		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2325 		if (IS_ERR(lu_gp_mem))
2326 			return PTR_ERR(lu_gp_mem);
2327 
2328 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2329 		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2330 				default_lu_gp);
2331 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2332 
2333 		pr_debug("%s: Adding to default ALUA LU Group:"
2334 			" core/alua/lu_gps/default_lu_gp\n",
2335 			dev->transport->name);
2336 	}
2337 
2338 	return 0;
2339 }
2340