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