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 	if (in_interrupt())
864 		return 0;
865 	/*
866 	 * The ALUA Active/NonOptimized access state delay can be disabled
867 	 * in via configfs with a value of zero
868 	 */
869 	if (!cmd->alua_nonop_delay)
870 		return 0;
871 	/*
872 	 * struct se_cmd->alua_nonop_delay gets set by a target port group
873 	 * defined interval in core_alua_state_nonoptimized()
874 	 */
875 	msleep_interruptible(cmd->alua_nonop_delay);
876 	return 0;
877 }
878 EXPORT_SYMBOL(core_alua_check_nonop_delay);
879 
880 static int core_alua_write_tpg_metadata(
881 	const char *path,
882 	unsigned char *md_buf,
883 	u32 md_buf_len)
884 {
885 	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
886 	loff_t pos = 0;
887 	int ret;
888 
889 	if (IS_ERR(file)) {
890 		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
891 		return -ENODEV;
892 	}
893 	ret = kernel_write(file, md_buf, md_buf_len, &pos);
894 	if (ret < 0)
895 		pr_err("Error writing ALUA metadata file: %s\n", path);
896 	fput(file);
897 	return (ret < 0) ? -EIO : 0;
898 }
899 
900 static int core_alua_update_tpg_primary_metadata(
901 	struct t10_alua_tg_pt_gp *tg_pt_gp)
902 {
903 	unsigned char *md_buf;
904 	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
905 	char *path;
906 	int len, rc;
907 
908 	lockdep_assert_held(&tg_pt_gp->tg_pt_gp_transition_mutex);
909 
910 	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
911 	if (!md_buf) {
912 		pr_err("Unable to allocate buf for ALUA metadata\n");
913 		return -ENOMEM;
914 	}
915 
916 	len = snprintf(md_buf, ALUA_MD_BUF_LEN,
917 			"tg_pt_gp_id=%hu\n"
918 			"alua_access_state=0x%02x\n"
919 			"alua_access_status=0x%02x\n",
920 			tg_pt_gp->tg_pt_gp_id,
921 			tg_pt_gp->tg_pt_gp_alua_access_state,
922 			tg_pt_gp->tg_pt_gp_alua_access_status);
923 
924 	rc = -ENOMEM;
925 	path = kasprintf(GFP_KERNEL, "%s/alua/tpgs_%s/%s", db_root,
926 			&wwn->unit_serial[0],
927 			config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
928 	if (path) {
929 		rc = core_alua_write_tpg_metadata(path, md_buf, len);
930 		kfree(path);
931 	}
932 	kfree(md_buf);
933 	return rc;
934 }
935 
936 static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
937 {
938 	struct se_dev_entry *se_deve;
939 	struct se_lun *lun;
940 	struct se_lun_acl *lacl;
941 
942 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
943 	list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
944 				lun_tg_pt_gp_link) {
945 		/*
946 		 * After an implicit target port asymmetric access state
947 		 * change, a device server shall establish a unit attention
948 		 * condition for the initiator port associated with every I_T
949 		 * nexus with the additional sense code set to ASYMMETRIC
950 		 * ACCESS STATE CHANGED.
951 		 *
952 		 * After an explicit target port asymmetric access state
953 		 * change, a device server shall establish a unit attention
954 		 * condition with the additional sense code set to ASYMMETRIC
955 		 * ACCESS STATE CHANGED for the initiator port associated with
956 		 * every I_T nexus other than the I_T nexus on which the SET
957 		 * TARGET PORT GROUPS command
958 		 */
959 		if (!percpu_ref_tryget_live(&lun->lun_ref))
960 			continue;
961 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
962 
963 		spin_lock(&lun->lun_deve_lock);
964 		list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
965 			lacl = rcu_dereference_check(se_deve->se_lun_acl,
966 					lockdep_is_held(&lun->lun_deve_lock));
967 
968 			/*
969 			 * spc4r37 p.242:
970 			 * After an explicit target port asymmetric access
971 			 * state change, a device server shall establish a
972 			 * unit attention condition with the additional sense
973 			 * code set to ASYMMETRIC ACCESS STATE CHANGED for
974 			 * the initiator port associated with every I_T nexus
975 			 * other than the I_T nexus on which the SET TARGET
976 			 * PORT GROUPS command was received.
977 			 */
978 			if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
979 			     ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
980 			   (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
981 			    (tg_pt_gp->tg_pt_gp_alua_lun == lun))
982 				continue;
983 
984 			/*
985 			 * se_deve->se_lun_acl pointer may be NULL for a
986 			 * entry created without explicit Node+MappedLUN ACLs
987 			 */
988 			if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
989 			    (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
990 				continue;
991 
992 			core_scsi3_ua_allocate(se_deve, 0x2A,
993 				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
994 		}
995 		spin_unlock(&lun->lun_deve_lock);
996 
997 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
998 		percpu_ref_put(&lun->lun_ref);
999 	}
1000 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1001 }
1002 
1003 static int core_alua_do_transition_tg_pt(
1004 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1005 	int new_state,
1006 	int explicit)
1007 {
1008 	int prev_state;
1009 
1010 	mutex_lock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1011 	/* Nothing to be done here */
1012 	if (tg_pt_gp->tg_pt_gp_alua_access_state == new_state) {
1013 		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1014 		return 0;
1015 	}
1016 
1017 	if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION) {
1018 		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1019 		return -EAGAIN;
1020 	}
1021 
1022 	/*
1023 	 * Save the old primary ALUA access state, and set the current state
1024 	 * to ALUA_ACCESS_STATE_TRANSITION.
1025 	 */
1026 	prev_state = tg_pt_gp->tg_pt_gp_alua_access_state;
1027 	tg_pt_gp->tg_pt_gp_alua_access_state = ALUA_ACCESS_STATE_TRANSITION;
1028 	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
1029 				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1030 				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1031 
1032 	core_alua_queue_state_change_ua(tg_pt_gp);
1033 
1034 	if (new_state == ALUA_ACCESS_STATE_TRANSITION) {
1035 		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1036 		return 0;
1037 	}
1038 
1039 	/*
1040 	 * Check for the optional ALUA primary state transition delay
1041 	 */
1042 	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
1043 		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1044 
1045 	/*
1046 	 * Set the current primary ALUA access state to the requested new state
1047 	 */
1048 	tg_pt_gp->tg_pt_gp_alua_access_state = new_state;
1049 
1050 	/*
1051 	 * Update the ALUA metadata buf that has been allocated in
1052 	 * core_alua_do_port_transition(), this metadata will be written
1053 	 * to struct file.
1054 	 *
1055 	 * Note that there is the case where we do not want to update the
1056 	 * metadata when the saved metadata is being parsed in userspace
1057 	 * when setting the existing port access state and access status.
1058 	 *
1059 	 * Also note that the failure to write out the ALUA metadata to
1060 	 * struct file does NOT affect the actual ALUA transition.
1061 	 */
1062 	if (tg_pt_gp->tg_pt_gp_write_metadata) {
1063 		core_alua_update_tpg_primary_metadata(tg_pt_gp);
1064 	}
1065 
1066 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1067 		" from primary access state %s to %s\n", (explicit) ? "explicit" :
1068 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1069 		tg_pt_gp->tg_pt_gp_id,
1070 		core_alua_dump_state(prev_state),
1071 		core_alua_dump_state(new_state));
1072 
1073 	core_alua_queue_state_change_ua(tg_pt_gp);
1074 
1075 	mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1076 	return 0;
1077 }
1078 
1079 int core_alua_do_port_transition(
1080 	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
1081 	struct se_device *l_dev,
1082 	struct se_lun *l_lun,
1083 	struct se_node_acl *l_nacl,
1084 	int new_state,
1085 	int explicit)
1086 {
1087 	struct se_device *dev;
1088 	struct t10_alua_lu_gp *lu_gp;
1089 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
1090 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1091 	int primary, valid_states, rc = 0;
1092 
1093 	if (l_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
1094 		return -ENODEV;
1095 
1096 	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
1097 	if (core_alua_check_transition(new_state, valid_states, &primary,
1098 				       explicit) != 0)
1099 		return -EINVAL;
1100 
1101 	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
1102 	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
1103 	lu_gp = local_lu_gp_mem->lu_gp;
1104 	atomic_inc(&lu_gp->lu_gp_ref_cnt);
1105 	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
1106 	/*
1107 	 * For storage objects that are members of the 'default_lu_gp',
1108 	 * we only do transition on the passed *l_tp_pt_gp, and not
1109 	 * on all of the matching target port groups IDs in default_lu_gp.
1110 	 */
1111 	if (!lu_gp->lu_gp_id) {
1112 		/*
1113 		 * core_alua_do_transition_tg_pt() will always return
1114 		 * success.
1115 		 */
1116 		l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1117 		l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1118 		rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
1119 						   new_state, explicit);
1120 		atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1121 		return rc;
1122 	}
1123 	/*
1124 	 * For all other LU groups aside from 'default_lu_gp', walk all of
1125 	 * the associated storage objects looking for a matching target port
1126 	 * group ID from the local target port group.
1127 	 */
1128 	spin_lock(&lu_gp->lu_gp_lock);
1129 	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
1130 				lu_gp_mem_list) {
1131 
1132 		dev = lu_gp_mem->lu_gp_mem_dev;
1133 		atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1134 		spin_unlock(&lu_gp->lu_gp_lock);
1135 
1136 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1137 		list_for_each_entry(tg_pt_gp,
1138 				&dev->t10_alua.tg_pt_gps_list,
1139 				tg_pt_gp_list) {
1140 
1141 			if (!tg_pt_gp->tg_pt_gp_valid_id)
1142 				continue;
1143 			/*
1144 			 * If the target behavior port asymmetric access state
1145 			 * is changed for any target port group accessible via
1146 			 * a logical unit within a LU group, the target port
1147 			 * behavior group asymmetric access states for the same
1148 			 * target port group accessible via other logical units
1149 			 * in that LU group will also change.
1150 			 */
1151 			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
1152 				continue;
1153 
1154 			if (l_tg_pt_gp == tg_pt_gp) {
1155 				tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1156 				tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1157 			} else {
1158 				tg_pt_gp->tg_pt_gp_alua_lun = NULL;
1159 				tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
1160 			}
1161 			atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1162 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1163 			/*
1164 			 * core_alua_do_transition_tg_pt() will always return
1165 			 * success.
1166 			 */
1167 			rc = core_alua_do_transition_tg_pt(tg_pt_gp,
1168 					new_state, explicit);
1169 
1170 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1171 			atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1172 			if (rc)
1173 				break;
1174 		}
1175 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1176 
1177 		spin_lock(&lu_gp->lu_gp_lock);
1178 		atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1179 	}
1180 	spin_unlock(&lu_gp->lu_gp_lock);
1181 
1182 	if (!rc) {
1183 		pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1184 			 " Group IDs: %hu %s transition to primary state: %s\n",
1185 			 config_item_name(&lu_gp->lu_gp_group.cg_item),
1186 			 l_tg_pt_gp->tg_pt_gp_id,
1187 			 (explicit) ? "explicit" : "implicit",
1188 			 core_alua_dump_state(new_state));
1189 	}
1190 
1191 	atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1192 	return rc;
1193 }
1194 
1195 static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
1196 {
1197 	struct se_portal_group *se_tpg = lun->lun_tpg;
1198 	unsigned char *md_buf;
1199 	char *path;
1200 	int len, rc;
1201 
1202 	mutex_lock(&lun->lun_tg_pt_md_mutex);
1203 
1204 	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
1205 	if (!md_buf) {
1206 		pr_err("Unable to allocate buf for ALUA metadata\n");
1207 		rc = -ENOMEM;
1208 		goto out_unlock;
1209 	}
1210 
1211 	len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
1212 			"alua_tg_pt_status=0x%02x\n",
1213 			atomic_read(&lun->lun_tg_pt_secondary_offline),
1214 			lun->lun_tg_pt_secondary_stat);
1215 
1216 	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL) {
1217 		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s+%hu/lun_%llu",
1218 				db_root, se_tpg->se_tpg_tfo->fabric_name,
1219 				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1220 				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg),
1221 				lun->unpacked_lun);
1222 	} else {
1223 		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s/lun_%llu",
1224 				db_root, se_tpg->se_tpg_tfo->fabric_name,
1225 				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1226 				lun->unpacked_lun);
1227 	}
1228 	if (!path) {
1229 		rc = -ENOMEM;
1230 		goto out_free;
1231 	}
1232 
1233 	rc = core_alua_write_tpg_metadata(path, md_buf, len);
1234 	kfree(path);
1235 out_free:
1236 	kfree(md_buf);
1237 out_unlock:
1238 	mutex_unlock(&lun->lun_tg_pt_md_mutex);
1239 	return rc;
1240 }
1241 
1242 static int core_alua_set_tg_pt_secondary_state(
1243 	struct se_lun *lun,
1244 	int explicit,
1245 	int offline)
1246 {
1247 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1248 	int trans_delay_msecs;
1249 
1250 	spin_lock(&lun->lun_tg_pt_gp_lock);
1251 	tg_pt_gp = lun->lun_tg_pt_gp;
1252 	if (!tg_pt_gp) {
1253 		spin_unlock(&lun->lun_tg_pt_gp_lock);
1254 		pr_err("Unable to complete secondary state"
1255 				" transition\n");
1256 		return -EINVAL;
1257 	}
1258 	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1259 	/*
1260 	 * Set the secondary ALUA target port access state to OFFLINE
1261 	 * or release the previously secondary state for struct se_lun
1262 	 */
1263 	if (offline)
1264 		atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
1265 	else
1266 		atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
1267 
1268 	lun->lun_tg_pt_secondary_stat = (explicit) ?
1269 			ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1270 			ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1271 
1272 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1273 		" to secondary access state: %s\n", (explicit) ? "explicit" :
1274 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1275 		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1276 
1277 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1278 	/*
1279 	 * Do the optional transition delay after we set the secondary
1280 	 * ALUA access state.
1281 	 */
1282 	if (trans_delay_msecs != 0)
1283 		msleep_interruptible(trans_delay_msecs);
1284 	/*
1285 	 * See if we need to update the ALUA fabric port metadata for
1286 	 * secondary state and status
1287 	 */
1288 	if (lun->lun_tg_pt_secondary_write_md)
1289 		core_alua_update_tpg_secondary_metadata(lun);
1290 
1291 	return 0;
1292 }
1293 
1294 struct t10_alua_lba_map *
1295 core_alua_allocate_lba_map(struct list_head *list,
1296 			   u64 first_lba, u64 last_lba)
1297 {
1298 	struct t10_alua_lba_map *lba_map;
1299 
1300 	lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
1301 	if (!lba_map) {
1302 		pr_err("Unable to allocate struct t10_alua_lba_map\n");
1303 		return ERR_PTR(-ENOMEM);
1304 	}
1305 	INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
1306 	lba_map->lba_map_first_lba = first_lba;
1307 	lba_map->lba_map_last_lba = last_lba;
1308 
1309 	list_add_tail(&lba_map->lba_map_list, list);
1310 	return lba_map;
1311 }
1312 
1313 int
1314 core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
1315 			       int pg_id, int state)
1316 {
1317 	struct t10_alua_lba_map_member *lba_map_mem;
1318 
1319 	list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
1320 			    lba_map_mem_list) {
1321 		if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
1322 			pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
1323 			return -EINVAL;
1324 		}
1325 	}
1326 
1327 	lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
1328 	if (!lba_map_mem) {
1329 		pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
1330 		return -ENOMEM;
1331 	}
1332 	lba_map_mem->lba_map_mem_alua_state = state;
1333 	lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
1334 
1335 	list_add_tail(&lba_map_mem->lba_map_mem_list,
1336 		      &lba_map->lba_map_mem_list);
1337 	return 0;
1338 }
1339 
1340 void
1341 core_alua_free_lba_map(struct list_head *lba_list)
1342 {
1343 	struct t10_alua_lba_map *lba_map, *lba_map_tmp;
1344 	struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
1345 
1346 	list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
1347 				 lba_map_list) {
1348 		list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
1349 					 &lba_map->lba_map_mem_list,
1350 					 lba_map_mem_list) {
1351 			list_del(&lba_map_mem->lba_map_mem_list);
1352 			kmem_cache_free(t10_alua_lba_map_mem_cache,
1353 					lba_map_mem);
1354 		}
1355 		list_del(&lba_map->lba_map_list);
1356 		kmem_cache_free(t10_alua_lba_map_cache, lba_map);
1357 	}
1358 }
1359 
1360 void
1361 core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
1362 		      int segment_size, int segment_mult)
1363 {
1364 	struct list_head old_lba_map_list;
1365 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1366 	int activate = 0, supported;
1367 
1368 	INIT_LIST_HEAD(&old_lba_map_list);
1369 	spin_lock(&dev->t10_alua.lba_map_lock);
1370 	dev->t10_alua.lba_map_segment_size = segment_size;
1371 	dev->t10_alua.lba_map_segment_multiplier = segment_mult;
1372 	list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
1373 	if (lba_map_list) {
1374 		list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
1375 		activate = 1;
1376 	}
1377 	spin_unlock(&dev->t10_alua.lba_map_lock);
1378 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1379 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1380 			    tg_pt_gp_list) {
1381 
1382 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1383 			continue;
1384 		supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
1385 		if (activate)
1386 			supported |= ALUA_LBD_SUP;
1387 		else
1388 			supported &= ~ALUA_LBD_SUP;
1389 		tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
1390 	}
1391 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1392 	core_alua_free_lba_map(&old_lba_map_list);
1393 }
1394 
1395 struct t10_alua_lu_gp *
1396 core_alua_allocate_lu_gp(const char *name, int def_group)
1397 {
1398 	struct t10_alua_lu_gp *lu_gp;
1399 
1400 	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1401 	if (!lu_gp) {
1402 		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1403 		return ERR_PTR(-ENOMEM);
1404 	}
1405 	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1406 	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1407 	spin_lock_init(&lu_gp->lu_gp_lock);
1408 	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1409 
1410 	if (def_group) {
1411 		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1412 		lu_gp->lu_gp_valid_id = 1;
1413 		alua_lu_gps_count++;
1414 	}
1415 
1416 	return lu_gp;
1417 }
1418 
1419 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1420 {
1421 	struct t10_alua_lu_gp *lu_gp_tmp;
1422 	u16 lu_gp_id_tmp;
1423 	/*
1424 	 * The lu_gp->lu_gp_id may only be set once..
1425 	 */
1426 	if (lu_gp->lu_gp_valid_id) {
1427 		pr_warn("ALUA LU Group already has a valid ID,"
1428 			" ignoring request\n");
1429 		return -EINVAL;
1430 	}
1431 
1432 	spin_lock(&lu_gps_lock);
1433 	if (alua_lu_gps_count == 0x0000ffff) {
1434 		pr_err("Maximum ALUA alua_lu_gps_count:"
1435 				" 0x0000ffff reached\n");
1436 		spin_unlock(&lu_gps_lock);
1437 		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1438 		return -ENOSPC;
1439 	}
1440 again:
1441 	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1442 				alua_lu_gps_counter++;
1443 
1444 	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1445 		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1446 			if (!lu_gp_id)
1447 				goto again;
1448 
1449 			pr_warn("ALUA Logical Unit Group ID: %hu"
1450 				" already exists, ignoring request\n",
1451 				lu_gp_id);
1452 			spin_unlock(&lu_gps_lock);
1453 			return -EINVAL;
1454 		}
1455 	}
1456 
1457 	lu_gp->lu_gp_id = lu_gp_id_tmp;
1458 	lu_gp->lu_gp_valid_id = 1;
1459 	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1460 	alua_lu_gps_count++;
1461 	spin_unlock(&lu_gps_lock);
1462 
1463 	return 0;
1464 }
1465 
1466 static struct t10_alua_lu_gp_member *
1467 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1468 {
1469 	struct t10_alua_lu_gp_member *lu_gp_mem;
1470 
1471 	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1472 	if (!lu_gp_mem) {
1473 		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1474 		return ERR_PTR(-ENOMEM);
1475 	}
1476 	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1477 	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1478 	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1479 
1480 	lu_gp_mem->lu_gp_mem_dev = dev;
1481 	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1482 
1483 	return lu_gp_mem;
1484 }
1485 
1486 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1487 {
1488 	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1489 	/*
1490 	 * Once we have reached this point, config_item_put() has
1491 	 * already been called from target_core_alua_drop_lu_gp().
1492 	 *
1493 	 * Here, we remove the *lu_gp from the global list so that
1494 	 * no associations can be made while we are releasing
1495 	 * struct t10_alua_lu_gp.
1496 	 */
1497 	spin_lock(&lu_gps_lock);
1498 	list_del(&lu_gp->lu_gp_node);
1499 	alua_lu_gps_count--;
1500 	spin_unlock(&lu_gps_lock);
1501 	/*
1502 	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1503 	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1504 	 * released with core_alua_put_lu_gp_from_name()
1505 	 */
1506 	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1507 		cpu_relax();
1508 	/*
1509 	 * Release reference to struct t10_alua_lu_gp * from all associated
1510 	 * struct se_device.
1511 	 */
1512 	spin_lock(&lu_gp->lu_gp_lock);
1513 	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1514 				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1515 		if (lu_gp_mem->lu_gp_assoc) {
1516 			list_del(&lu_gp_mem->lu_gp_mem_list);
1517 			lu_gp->lu_gp_members--;
1518 			lu_gp_mem->lu_gp_assoc = 0;
1519 		}
1520 		spin_unlock(&lu_gp->lu_gp_lock);
1521 		/*
1522 		 *
1523 		 * lu_gp_mem is associated with a single
1524 		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1525 		 * struct se_device is released via core_alua_free_lu_gp_mem().
1526 		 *
1527 		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1528 		 * we want to re-associate a given lu_gp_mem with default_lu_gp.
1529 		 */
1530 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1531 		if (lu_gp != default_lu_gp)
1532 			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1533 					default_lu_gp);
1534 		else
1535 			lu_gp_mem->lu_gp = NULL;
1536 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1537 
1538 		spin_lock(&lu_gp->lu_gp_lock);
1539 	}
1540 	spin_unlock(&lu_gp->lu_gp_lock);
1541 
1542 	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1543 }
1544 
1545 void core_alua_free_lu_gp_mem(struct se_device *dev)
1546 {
1547 	struct t10_alua_lu_gp *lu_gp;
1548 	struct t10_alua_lu_gp_member *lu_gp_mem;
1549 
1550 	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1551 	if (!lu_gp_mem)
1552 		return;
1553 
1554 	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1555 		cpu_relax();
1556 
1557 	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1558 	lu_gp = lu_gp_mem->lu_gp;
1559 	if (lu_gp) {
1560 		spin_lock(&lu_gp->lu_gp_lock);
1561 		if (lu_gp_mem->lu_gp_assoc) {
1562 			list_del(&lu_gp_mem->lu_gp_mem_list);
1563 			lu_gp->lu_gp_members--;
1564 			lu_gp_mem->lu_gp_assoc = 0;
1565 		}
1566 		spin_unlock(&lu_gp->lu_gp_lock);
1567 		lu_gp_mem->lu_gp = NULL;
1568 	}
1569 	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1570 
1571 	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1572 }
1573 
1574 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1575 {
1576 	struct t10_alua_lu_gp *lu_gp;
1577 	struct config_item *ci;
1578 
1579 	spin_lock(&lu_gps_lock);
1580 	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1581 		if (!lu_gp->lu_gp_valid_id)
1582 			continue;
1583 		ci = &lu_gp->lu_gp_group.cg_item;
1584 		if (!strcmp(config_item_name(ci), name)) {
1585 			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1586 			spin_unlock(&lu_gps_lock);
1587 			return lu_gp;
1588 		}
1589 	}
1590 	spin_unlock(&lu_gps_lock);
1591 
1592 	return NULL;
1593 }
1594 
1595 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1596 {
1597 	spin_lock(&lu_gps_lock);
1598 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1599 	spin_unlock(&lu_gps_lock);
1600 }
1601 
1602 /*
1603  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1604  */
1605 void __core_alua_attach_lu_gp_mem(
1606 	struct t10_alua_lu_gp_member *lu_gp_mem,
1607 	struct t10_alua_lu_gp *lu_gp)
1608 {
1609 	spin_lock(&lu_gp->lu_gp_lock);
1610 	lu_gp_mem->lu_gp = lu_gp;
1611 	lu_gp_mem->lu_gp_assoc = 1;
1612 	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1613 	lu_gp->lu_gp_members++;
1614 	spin_unlock(&lu_gp->lu_gp_lock);
1615 }
1616 
1617 /*
1618  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1619  */
1620 void __core_alua_drop_lu_gp_mem(
1621 	struct t10_alua_lu_gp_member *lu_gp_mem,
1622 	struct t10_alua_lu_gp *lu_gp)
1623 {
1624 	spin_lock(&lu_gp->lu_gp_lock);
1625 	list_del(&lu_gp_mem->lu_gp_mem_list);
1626 	lu_gp_mem->lu_gp = NULL;
1627 	lu_gp_mem->lu_gp_assoc = 0;
1628 	lu_gp->lu_gp_members--;
1629 	spin_unlock(&lu_gp->lu_gp_lock);
1630 }
1631 
1632 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1633 		const char *name, int def_group)
1634 {
1635 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1636 
1637 	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1638 	if (!tg_pt_gp) {
1639 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1640 		return NULL;
1641 	}
1642 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1643 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
1644 	mutex_init(&tg_pt_gp->tg_pt_gp_transition_mutex);
1645 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1646 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1647 	tg_pt_gp->tg_pt_gp_dev = dev;
1648 	tg_pt_gp->tg_pt_gp_alua_access_state =
1649 			ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
1650 	/*
1651 	 * Enable both explicit and implicit ALUA support by default
1652 	 */
1653 	tg_pt_gp->tg_pt_gp_alua_access_type =
1654 			TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1655 	/*
1656 	 * Set the default Active/NonOptimized Delay in milliseconds
1657 	 */
1658 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1659 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1660 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1661 
1662 	/*
1663 	 * Enable all supported states
1664 	 */
1665 	tg_pt_gp->tg_pt_gp_alua_supported_states =
1666 	    ALUA_T_SUP | ALUA_O_SUP |
1667 	    ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1668 
1669 	if (def_group) {
1670 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1671 		tg_pt_gp->tg_pt_gp_id =
1672 				dev->t10_alua.alua_tg_pt_gps_counter++;
1673 		tg_pt_gp->tg_pt_gp_valid_id = 1;
1674 		dev->t10_alua.alua_tg_pt_gps_count++;
1675 		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1676 			      &dev->t10_alua.tg_pt_gps_list);
1677 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1678 	}
1679 
1680 	return tg_pt_gp;
1681 }
1682 
1683 int core_alua_set_tg_pt_gp_id(
1684 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1685 	u16 tg_pt_gp_id)
1686 {
1687 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1688 	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1689 	u16 tg_pt_gp_id_tmp;
1690 
1691 	/*
1692 	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1693 	 */
1694 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1695 		pr_warn("ALUA TG PT Group already has a valid ID,"
1696 			" ignoring request\n");
1697 		return -EINVAL;
1698 	}
1699 
1700 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1701 	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1702 		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1703 			" 0x0000ffff reached\n");
1704 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1705 		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1706 		return -ENOSPC;
1707 	}
1708 again:
1709 	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1710 			dev->t10_alua.alua_tg_pt_gps_counter++;
1711 
1712 	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1713 			tg_pt_gp_list) {
1714 		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1715 			if (!tg_pt_gp_id)
1716 				goto again;
1717 
1718 			pr_err("ALUA Target Port Group ID: %hu already"
1719 				" exists, ignoring request\n", tg_pt_gp_id);
1720 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1721 			return -EINVAL;
1722 		}
1723 	}
1724 
1725 	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1726 	tg_pt_gp->tg_pt_gp_valid_id = 1;
1727 	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1728 			&dev->t10_alua.tg_pt_gps_list);
1729 	dev->t10_alua.alua_tg_pt_gps_count++;
1730 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1731 
1732 	return 0;
1733 }
1734 
1735 void core_alua_free_tg_pt_gp(
1736 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1737 {
1738 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1739 	struct se_lun *lun, *next;
1740 
1741 	/*
1742 	 * Once we have reached this point, config_item_put() has already
1743 	 * been called from target_core_alua_drop_tg_pt_gp().
1744 	 *
1745 	 * Here we remove *tg_pt_gp from the global list so that
1746 	 * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1747 	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1748 	 */
1749 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1750 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1751 		list_del(&tg_pt_gp->tg_pt_gp_list);
1752 		dev->t10_alua.alua_tg_pt_gps_count--;
1753 	}
1754 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1755 
1756 	/*
1757 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1758 	 * core_alua_get_tg_pt_gp_by_name() in
1759 	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1760 	 * to be released with core_alua_put_tg_pt_gp_from_name().
1761 	 */
1762 	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1763 		cpu_relax();
1764 
1765 	/*
1766 	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1767 	 * struct se_port.
1768 	 */
1769 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1770 	list_for_each_entry_safe(lun, next,
1771 			&tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
1772 		list_del_init(&lun->lun_tg_pt_gp_link);
1773 		tg_pt_gp->tg_pt_gp_members--;
1774 
1775 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1776 		/*
1777 		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1778 		 * assume we want to re-associate a given tg_pt_gp_mem with
1779 		 * default_tg_pt_gp.
1780 		 */
1781 		spin_lock(&lun->lun_tg_pt_gp_lock);
1782 		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1783 			__target_attach_tg_pt_gp(lun,
1784 					dev->t10_alua.default_tg_pt_gp);
1785 		} else
1786 			lun->lun_tg_pt_gp = NULL;
1787 		spin_unlock(&lun->lun_tg_pt_gp_lock);
1788 
1789 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1790 	}
1791 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1792 
1793 	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1794 }
1795 
1796 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1797 		struct se_device *dev, const char *name)
1798 {
1799 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1800 	struct config_item *ci;
1801 
1802 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1803 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1804 			tg_pt_gp_list) {
1805 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1806 			continue;
1807 		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1808 		if (!strcmp(config_item_name(ci), name)) {
1809 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1810 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1811 			return tg_pt_gp;
1812 		}
1813 	}
1814 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1815 
1816 	return NULL;
1817 }
1818 
1819 static void core_alua_put_tg_pt_gp_from_name(
1820 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1821 {
1822 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1823 
1824 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1825 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1826 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1827 }
1828 
1829 static void __target_attach_tg_pt_gp(struct se_lun *lun,
1830 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1831 {
1832 	struct se_dev_entry *se_deve;
1833 
1834 	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1835 
1836 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1837 	lun->lun_tg_pt_gp = tg_pt_gp;
1838 	list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
1839 	tg_pt_gp->tg_pt_gp_members++;
1840 	spin_lock(&lun->lun_deve_lock);
1841 	list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
1842 		core_scsi3_ua_allocate(se_deve, 0x3f,
1843 				       ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
1844 	spin_unlock(&lun->lun_deve_lock);
1845 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1846 }
1847 
1848 void target_attach_tg_pt_gp(struct se_lun *lun,
1849 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1850 {
1851 	spin_lock(&lun->lun_tg_pt_gp_lock);
1852 	__target_attach_tg_pt_gp(lun, tg_pt_gp);
1853 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1854 }
1855 
1856 static void __target_detach_tg_pt_gp(struct se_lun *lun,
1857 		struct t10_alua_tg_pt_gp *tg_pt_gp)
1858 {
1859 	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1860 
1861 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1862 	list_del_init(&lun->lun_tg_pt_gp_link);
1863 	tg_pt_gp->tg_pt_gp_members--;
1864 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1865 
1866 	lun->lun_tg_pt_gp = NULL;
1867 }
1868 
1869 void target_detach_tg_pt_gp(struct se_lun *lun)
1870 {
1871 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1872 
1873 	spin_lock(&lun->lun_tg_pt_gp_lock);
1874 	tg_pt_gp = lun->lun_tg_pt_gp;
1875 	if (tg_pt_gp)
1876 		__target_detach_tg_pt_gp(lun, tg_pt_gp);
1877 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1878 }
1879 
1880 ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
1881 {
1882 	struct config_item *tg_pt_ci;
1883 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1884 	ssize_t len = 0;
1885 
1886 	spin_lock(&lun->lun_tg_pt_gp_lock);
1887 	tg_pt_gp = lun->lun_tg_pt_gp;
1888 	if (tg_pt_gp) {
1889 		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1890 		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1891 			" %hu\nTG Port Primary Access State: %s\nTG Port "
1892 			"Primary Access Status: %s\nTG Port Secondary Access"
1893 			" State: %s\nTG Port Secondary Access Status: %s\n",
1894 			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1895 			core_alua_dump_state(
1896 				tg_pt_gp->tg_pt_gp_alua_access_state),
1897 			core_alua_dump_status(
1898 				tg_pt_gp->tg_pt_gp_alua_access_status),
1899 			atomic_read(&lun->lun_tg_pt_secondary_offline) ?
1900 			"Offline" : "None",
1901 			core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
1902 	}
1903 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1904 
1905 	return len;
1906 }
1907 
1908 ssize_t core_alua_store_tg_pt_gp_info(
1909 	struct se_lun *lun,
1910 	const char *page,
1911 	size_t count)
1912 {
1913 	struct se_portal_group *tpg = lun->lun_tpg;
1914 	/*
1915 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
1916 	 * reference to se_device->dev_group.
1917 	 */
1918 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
1919 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1920 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1921 	int move = 0;
1922 
1923 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
1924 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
1925 		return -ENODEV;
1926 
1927 	if (count > TG_PT_GROUP_NAME_BUF) {
1928 		pr_err("ALUA Target Port Group alias too large!\n");
1929 		return -EINVAL;
1930 	}
1931 	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1932 	memcpy(buf, page, count);
1933 	/*
1934 	 * Any ALUA target port group alias besides "NULL" means we will be
1935 	 * making a new group association.
1936 	 */
1937 	if (strcmp(strstrip(buf), "NULL")) {
1938 		/*
1939 		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1940 		 * struct t10_alua_tg_pt_gp.  This reference is released with
1941 		 * core_alua_put_tg_pt_gp_from_name() below.
1942 		 */
1943 		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1944 					strstrip(buf));
1945 		if (!tg_pt_gp_new)
1946 			return -ENODEV;
1947 	}
1948 
1949 	spin_lock(&lun->lun_tg_pt_gp_lock);
1950 	tg_pt_gp = lun->lun_tg_pt_gp;
1951 	if (tg_pt_gp) {
1952 		/*
1953 		 * Clearing an existing tg_pt_gp association, and replacing
1954 		 * with the default_tg_pt_gp.
1955 		 */
1956 		if (!tg_pt_gp_new) {
1957 			pr_debug("Target_Core_ConfigFS: Moving"
1958 				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
1959 				" alua/%s, ID: %hu back to"
1960 				" default_tg_pt_gp\n",
1961 				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1962 				tpg->se_tpg_tfo->tpg_get_tag(tpg),
1963 				config_item_name(&lun->lun_group.cg_item),
1964 				config_item_name(
1965 					&tg_pt_gp->tg_pt_gp_group.cg_item),
1966 				tg_pt_gp->tg_pt_gp_id);
1967 
1968 			__target_detach_tg_pt_gp(lun, tg_pt_gp);
1969 			__target_attach_tg_pt_gp(lun,
1970 					dev->t10_alua.default_tg_pt_gp);
1971 			spin_unlock(&lun->lun_tg_pt_gp_lock);
1972 
1973 			return count;
1974 		}
1975 		__target_detach_tg_pt_gp(lun, tg_pt_gp);
1976 		move = 1;
1977 	}
1978 
1979 	__target_attach_tg_pt_gp(lun, tg_pt_gp_new);
1980 	spin_unlock(&lun->lun_tg_pt_gp_lock);
1981 	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1982 		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
1983 		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1984 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
1985 		config_item_name(&lun->lun_group.cg_item),
1986 		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1987 		tg_pt_gp_new->tg_pt_gp_id);
1988 
1989 	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1990 	return count;
1991 }
1992 
1993 ssize_t core_alua_show_access_type(
1994 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1995 	char *page)
1996 {
1997 	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
1998 	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
1999 		return sprintf(page, "Implicit and Explicit\n");
2000 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
2001 		return sprintf(page, "Implicit\n");
2002 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
2003 		return sprintf(page, "Explicit\n");
2004 	else
2005 		return sprintf(page, "None\n");
2006 }
2007 
2008 ssize_t core_alua_store_access_type(
2009 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2010 	const char *page,
2011 	size_t count)
2012 {
2013 	unsigned long tmp;
2014 	int ret;
2015 
2016 	ret = kstrtoul(page, 0, &tmp);
2017 	if (ret < 0) {
2018 		pr_err("Unable to extract alua_access_type\n");
2019 		return ret;
2020 	}
2021 	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
2022 		pr_err("Illegal value for alua_access_type:"
2023 				" %lu\n", tmp);
2024 		return -EINVAL;
2025 	}
2026 	if (tmp == 3)
2027 		tg_pt_gp->tg_pt_gp_alua_access_type =
2028 			TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
2029 	else if (tmp == 2)
2030 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
2031 	else if (tmp == 1)
2032 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
2033 	else
2034 		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
2035 
2036 	return count;
2037 }
2038 
2039 ssize_t core_alua_show_nonop_delay_msecs(
2040 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2041 	char *page)
2042 {
2043 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
2044 }
2045 
2046 ssize_t core_alua_store_nonop_delay_msecs(
2047 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2048 	const char *page,
2049 	size_t count)
2050 {
2051 	unsigned long tmp;
2052 	int ret;
2053 
2054 	ret = kstrtoul(page, 0, &tmp);
2055 	if (ret < 0) {
2056 		pr_err("Unable to extract nonop_delay_msecs\n");
2057 		return ret;
2058 	}
2059 	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
2060 		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
2061 			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
2062 			ALUA_MAX_NONOP_DELAY_MSECS);
2063 		return -EINVAL;
2064 	}
2065 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
2066 
2067 	return count;
2068 }
2069 
2070 ssize_t core_alua_show_trans_delay_msecs(
2071 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2072 	char *page)
2073 {
2074 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
2075 }
2076 
2077 ssize_t core_alua_store_trans_delay_msecs(
2078 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2079 	const char *page,
2080 	size_t count)
2081 {
2082 	unsigned long tmp;
2083 	int ret;
2084 
2085 	ret = kstrtoul(page, 0, &tmp);
2086 	if (ret < 0) {
2087 		pr_err("Unable to extract trans_delay_msecs\n");
2088 		return ret;
2089 	}
2090 	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
2091 		pr_err("Passed trans_delay_msecs: %lu, exceeds"
2092 			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
2093 			ALUA_MAX_TRANS_DELAY_MSECS);
2094 		return -EINVAL;
2095 	}
2096 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
2097 
2098 	return count;
2099 }
2100 
2101 ssize_t core_alua_show_implicit_trans_secs(
2102 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2103 	char *page)
2104 {
2105 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
2106 }
2107 
2108 ssize_t core_alua_store_implicit_trans_secs(
2109 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2110 	const char *page,
2111 	size_t count)
2112 {
2113 	unsigned long tmp;
2114 	int ret;
2115 
2116 	ret = kstrtoul(page, 0, &tmp);
2117 	if (ret < 0) {
2118 		pr_err("Unable to extract implicit_trans_secs\n");
2119 		return ret;
2120 	}
2121 	if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
2122 		pr_err("Passed implicit_trans_secs: %lu, exceeds"
2123 			" ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
2124 			ALUA_MAX_IMPLICIT_TRANS_SECS);
2125 		return  -EINVAL;
2126 	}
2127 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
2128 
2129 	return count;
2130 }
2131 
2132 ssize_t core_alua_show_preferred_bit(
2133 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2134 	char *page)
2135 {
2136 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
2137 }
2138 
2139 ssize_t core_alua_store_preferred_bit(
2140 	struct t10_alua_tg_pt_gp *tg_pt_gp,
2141 	const char *page,
2142 	size_t count)
2143 {
2144 	unsigned long tmp;
2145 	int ret;
2146 
2147 	ret = kstrtoul(page, 0, &tmp);
2148 	if (ret < 0) {
2149 		pr_err("Unable to extract preferred ALUA value\n");
2150 		return ret;
2151 	}
2152 	if ((tmp != 0) && (tmp != 1)) {
2153 		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
2154 		return -EINVAL;
2155 	}
2156 	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
2157 
2158 	return count;
2159 }
2160 
2161 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
2162 {
2163 	return sprintf(page, "%d\n",
2164 		atomic_read(&lun->lun_tg_pt_secondary_offline));
2165 }
2166 
2167 ssize_t core_alua_store_offline_bit(
2168 	struct se_lun *lun,
2169 	const char *page,
2170 	size_t count)
2171 {
2172 	/*
2173 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
2174 	 * reference to se_device->dev_group.
2175 	 */
2176 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
2177 	unsigned long tmp;
2178 	int ret;
2179 
2180 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
2181 	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
2182 		return -ENODEV;
2183 
2184 	ret = kstrtoul(page, 0, &tmp);
2185 	if (ret < 0) {
2186 		pr_err("Unable to extract alua_tg_pt_offline value\n");
2187 		return ret;
2188 	}
2189 	if ((tmp != 0) && (tmp != 1)) {
2190 		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
2191 				tmp);
2192 		return -EINVAL;
2193 	}
2194 
2195 	ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
2196 	if (ret < 0)
2197 		return -EINVAL;
2198 
2199 	return count;
2200 }
2201 
2202 ssize_t core_alua_show_secondary_status(
2203 	struct se_lun *lun,
2204 	char *page)
2205 {
2206 	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
2207 }
2208 
2209 ssize_t core_alua_store_secondary_status(
2210 	struct se_lun *lun,
2211 	const char *page,
2212 	size_t count)
2213 {
2214 	unsigned long tmp;
2215 	int ret;
2216 
2217 	ret = kstrtoul(page, 0, &tmp);
2218 	if (ret < 0) {
2219 		pr_err("Unable to extract alua_tg_pt_status\n");
2220 		return ret;
2221 	}
2222 	if ((tmp != ALUA_STATUS_NONE) &&
2223 	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
2224 	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
2225 		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2226 				tmp);
2227 		return -EINVAL;
2228 	}
2229 	lun->lun_tg_pt_secondary_stat = (int)tmp;
2230 
2231 	return count;
2232 }
2233 
2234 ssize_t core_alua_show_secondary_write_metadata(
2235 	struct se_lun *lun,
2236 	char *page)
2237 {
2238 	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
2239 }
2240 
2241 ssize_t core_alua_store_secondary_write_metadata(
2242 	struct se_lun *lun,
2243 	const char *page,
2244 	size_t count)
2245 {
2246 	unsigned long tmp;
2247 	int ret;
2248 
2249 	ret = kstrtoul(page, 0, &tmp);
2250 	if (ret < 0) {
2251 		pr_err("Unable to extract alua_tg_pt_write_md\n");
2252 		return ret;
2253 	}
2254 	if ((tmp != 0) && (tmp != 1)) {
2255 		pr_err("Illegal value for alua_tg_pt_write_md:"
2256 				" %lu\n", tmp);
2257 		return -EINVAL;
2258 	}
2259 	lun->lun_tg_pt_secondary_write_md = (int)tmp;
2260 
2261 	return count;
2262 }
2263 
2264 int core_setup_alua(struct se_device *dev)
2265 {
2266 	if (!(dev->transport_flags &
2267 	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
2268 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2269 		struct t10_alua_lu_gp_member *lu_gp_mem;
2270 
2271 		/*
2272 		 * Associate this struct se_device with the default ALUA
2273 		 * LUN Group.
2274 		 */
2275 		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2276 		if (IS_ERR(lu_gp_mem))
2277 			return PTR_ERR(lu_gp_mem);
2278 
2279 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2280 		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2281 				default_lu_gp);
2282 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2283 
2284 		pr_debug("%s: Adding to default ALUA LU Group:"
2285 			" core/alua/lu_gps/default_lu_gp\n",
2286 			dev->transport->name);
2287 	}
2288 
2289 	return 0;
2290 }
2291