1 /*******************************************************************************
2  * Filename:  target_core_alua.c
3  *
4  * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
5  *
6  * (c) Copyright 2009-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <linux/configfs.h>
29 #include <linux/export.h>
30 #include <linux/file.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_cmnd.h>
33 #include <asm/unaligned.h>
34 
35 #include <target/target_core_base.h>
36 #include <target/target_core_backend.h>
37 #include <target/target_core_fabric.h>
38 #include <target/target_core_configfs.h>
39 
40 #include "target_core_internal.h"
41 #include "target_core_alua.h"
42 #include "target_core_ua.h"
43 
44 static sense_reason_t core_alua_check_transition(int state, int *primary);
45 static int core_alua_set_tg_pt_secondary_state(
46 		struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
47 		struct se_port *port, int explict, int offline);
48 
49 static u16 alua_lu_gps_counter;
50 static u32 alua_lu_gps_count;
51 
52 static DEFINE_SPINLOCK(lu_gps_lock);
53 static LIST_HEAD(lu_gps_list);
54 
55 struct t10_alua_lu_gp *default_lu_gp;
56 
57 /*
58  * REPORT_TARGET_PORT_GROUPS
59  *
60  * See spc4r17 section 6.27
61  */
62 sense_reason_t
63 target_emulate_report_target_port_groups(struct se_cmd *cmd)
64 {
65 	struct se_device *dev = cmd->se_dev;
66 	struct se_port *port;
67 	struct t10_alua_tg_pt_gp *tg_pt_gp;
68 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
69 	unsigned char *buf;
70 	u32 rd_len = 0, off;
71 	int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
72 
73 	/*
74 	 * Skip over RESERVED area to first Target port group descriptor
75 	 * depending on the PARAMETER DATA FORMAT type..
76 	 */
77 	if (ext_hdr != 0)
78 		off = 8;
79 	else
80 		off = 4;
81 
82 	if (cmd->data_length < off) {
83 		pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
84 			" small for %s header\n", cmd->data_length,
85 			(ext_hdr) ? "extended" : "normal");
86 		return TCM_INVALID_CDB_FIELD;
87 	}
88 	buf = transport_kmap_data_sg(cmd);
89 	if (!buf)
90 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
91 
92 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
93 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
94 			tg_pt_gp_list) {
95 		/*
96 		 * Check if the Target port group and Target port descriptor list
97 		 * based on tg_pt_gp_members count will fit into the response payload.
98 		 * Otherwise, bump rd_len to let the initiator know we have exceeded
99 		 * the allocation length and the response is truncated.
100 		 */
101 		if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
102 		     cmd->data_length) {
103 			rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
104 			continue;
105 		}
106 		/*
107 		 * PREF: Preferred target port bit, determine if this
108 		 * bit should be set for port group.
109 		 */
110 		if (tg_pt_gp->tg_pt_gp_pref)
111 			buf[off] = 0x80;
112 		/*
113 		 * Set the ASYMMETRIC ACCESS State
114 		 */
115 		buf[off++] |= (atomic_read(
116 			&tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
117 		/*
118 		 * Set supported ASYMMETRIC ACCESS State bits
119 		 */
120 		buf[off] = 0x80; /* T_SUP */
121 		buf[off] |= 0x40; /* O_SUP */
122 		buf[off] |= 0x8; /* U_SUP */
123 		buf[off] |= 0x4; /* S_SUP */
124 		buf[off] |= 0x2; /* AN_SUP */
125 		buf[off++] |= 0x1; /* AO_SUP */
126 		/*
127 		 * TARGET PORT GROUP
128 		 */
129 		buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
130 		buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
131 
132 		off++; /* Skip over Reserved */
133 		/*
134 		 * STATUS CODE
135 		 */
136 		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
137 		/*
138 		 * Vendor Specific field
139 		 */
140 		buf[off++] = 0x00;
141 		/*
142 		 * TARGET PORT COUNT
143 		 */
144 		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
145 		rd_len += 8;
146 
147 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
148 		list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
149 				tg_pt_gp_mem_list) {
150 			port = tg_pt_gp_mem->tg_pt;
151 			/*
152 			 * Start Target Port descriptor format
153 			 *
154 			 * See spc4r17 section 6.2.7 Table 247
155 			 */
156 			off += 2; /* Skip over Obsolete */
157 			/*
158 			 * Set RELATIVE TARGET PORT IDENTIFIER
159 			 */
160 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
161 			buf[off++] = (port->sep_rtpi & 0xff);
162 			rd_len += 4;
163 		}
164 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
165 	}
166 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
167 	/*
168 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
169 	 */
170 	put_unaligned_be32(rd_len, &buf[0]);
171 
172 	/*
173 	 * Fill in the Extended header parameter data format if requested
174 	 */
175 	if (ext_hdr != 0) {
176 		buf[4] = 0x10;
177 		/*
178 		 * Set the implict transition time (in seconds) for the application
179 		 * client to use as a base for it's transition timeout value.
180 		 *
181 		 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
182 		 * this CDB was received upon to determine this value individually
183 		 * for ALUA target port group.
184 		 */
185 		port = cmd->se_lun->lun_sep;
186 		tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
187 		if (tg_pt_gp_mem) {
188 			spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
189 			tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
190 			if (tg_pt_gp)
191 				buf[5] = tg_pt_gp->tg_pt_gp_implict_trans_secs;
192 			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
193 		}
194 	}
195 	transport_kunmap_data_sg(cmd);
196 
197 	target_complete_cmd(cmd, GOOD);
198 	return 0;
199 }
200 
201 /*
202  * SET_TARGET_PORT_GROUPS for explict ALUA operation.
203  *
204  * See spc4r17 section 6.35
205  */
206 sense_reason_t
207 target_emulate_set_target_port_groups(struct se_cmd *cmd)
208 {
209 	struct se_device *dev = cmd->se_dev;
210 	struct se_port *port, *l_port = cmd->se_lun->lun_sep;
211 	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
212 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
213 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
214 	unsigned char *buf;
215 	unsigned char *ptr;
216 	sense_reason_t rc = TCM_NO_SENSE;
217 	u32 len = 4; /* Skip over RESERVED area in header */
218 	int alua_access_state, primary = 0;
219 	u16 tg_pt_id, rtpi;
220 
221 	if (!l_port)
222 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
223 
224 	if (cmd->data_length < 4) {
225 		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
226 			" small\n", cmd->data_length);
227 		return TCM_INVALID_PARAMETER_LIST;
228 	}
229 
230 	buf = transport_kmap_data_sg(cmd);
231 	if (!buf)
232 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
233 
234 	/*
235 	 * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
236 	 * for the local tg_pt_gp.
237 	 */
238 	l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
239 	if (!l_tg_pt_gp_mem) {
240 		pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
241 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
242 		goto out;
243 	}
244 	spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
245 	l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
246 	if (!l_tg_pt_gp) {
247 		spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
248 		pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
249 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
250 		goto out;
251 	}
252 	spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
253 
254 	if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)) {
255 		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
256 				" while TPGS_EXPLICT_ALUA is disabled\n");
257 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
258 		goto out;
259 	}
260 
261 	ptr = &buf[4]; /* Skip over RESERVED area in header */
262 
263 	while (len < cmd->data_length) {
264 		bool found = false;
265 		alua_access_state = (ptr[0] & 0x0f);
266 		/*
267 		 * Check the received ALUA access state, and determine if
268 		 * the state is a primary or secondary target port asymmetric
269 		 * access state.
270 		 */
271 		rc = core_alua_check_transition(alua_access_state, &primary);
272 		if (rc) {
273 			/*
274 			 * If the SET TARGET PORT GROUPS attempts to establish
275 			 * an invalid combination of target port asymmetric
276 			 * access states or attempts to establish an
277 			 * unsupported target port asymmetric access state,
278 			 * then the command shall be terminated with CHECK
279 			 * CONDITION status, with the sense key set to ILLEGAL
280 			 * REQUEST, and the additional sense code set to INVALID
281 			 * FIELD IN PARAMETER LIST.
282 			 */
283 			goto out;
284 		}
285 
286 		/*
287 		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
288 		 * specifies a primary target port asymmetric access state,
289 		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
290 		 * a primary target port group for which the primary target
291 		 * port asymmetric access state shall be changed. If the
292 		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
293 		 * port asymmetric access state, then the TARGET PORT GROUP OR
294 		 * TARGET PORT field specifies the relative target port
295 		 * identifier (see 3.1.120) of the target port for which the
296 		 * secondary target port asymmetric access state shall be
297 		 * changed.
298 		 */
299 		if (primary) {
300 			tg_pt_id = get_unaligned_be16(ptr + 2);
301 			/*
302 			 * Locate the matching target port group ID from
303 			 * the global tg_pt_gp list
304 			 */
305 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
306 			list_for_each_entry(tg_pt_gp,
307 					&dev->t10_alua.tg_pt_gps_list,
308 					tg_pt_gp_list) {
309 				if (!tg_pt_gp->tg_pt_gp_valid_id)
310 					continue;
311 
312 				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
313 					continue;
314 
315 				atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
316 				smp_mb__after_atomic_inc();
317 
318 				spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
319 
320 				if (!core_alua_do_port_transition(tg_pt_gp,
321 						dev, l_port, nacl,
322 						alua_access_state, 1))
323 					found = true;
324 
325 				spin_lock(&dev->t10_alua.tg_pt_gps_lock);
326 				atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
327 				smp_mb__after_atomic_dec();
328 				break;
329 			}
330 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
331 		} else {
332 			/*
333 			 * Extact the RELATIVE TARGET PORT IDENTIFIER to identify
334 			 * the Target Port in question for the the incoming
335 			 * SET_TARGET_PORT_GROUPS op.
336 			 */
337 			rtpi = get_unaligned_be16(ptr + 2);
338 			/*
339 			 * Locate the matching relative target port identifier
340 			 * for the struct se_device storage object.
341 			 */
342 			spin_lock(&dev->se_port_lock);
343 			list_for_each_entry(port, &dev->dev_sep_list,
344 							sep_list) {
345 				if (port->sep_rtpi != rtpi)
346 					continue;
347 
348 				tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
349 
350 				spin_unlock(&dev->se_port_lock);
351 
352 				if (!core_alua_set_tg_pt_secondary_state(
353 						tg_pt_gp_mem, port, 1, 1))
354 					found = true;
355 
356 				spin_lock(&dev->se_port_lock);
357 				break;
358 			}
359 			spin_unlock(&dev->se_port_lock);
360 		}
361 
362 		if (!found) {
363 			rc = TCM_INVALID_PARAMETER_LIST;
364 			goto out;
365 		}
366 
367 		ptr += 4;
368 		len += 4;
369 	}
370 
371 out:
372 	transport_kunmap_data_sg(cmd);
373 	if (!rc)
374 		target_complete_cmd(cmd, GOOD);
375 	return rc;
376 }
377 
378 static inline int core_alua_state_nonoptimized(
379 	struct se_cmd *cmd,
380 	unsigned char *cdb,
381 	int nonop_delay_msecs,
382 	u8 *alua_ascq)
383 {
384 	/*
385 	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
386 	 * later to determine if processing of this cmd needs to be
387 	 * temporarily delayed for the Active/NonOptimized primary access state.
388 	 */
389 	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
390 	cmd->alua_nonop_delay = nonop_delay_msecs;
391 	return 0;
392 }
393 
394 static inline int core_alua_state_standby(
395 	struct se_cmd *cmd,
396 	unsigned char *cdb,
397 	u8 *alua_ascq)
398 {
399 	/*
400 	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
401 	 * spc4r17 section 5.9.2.4.4
402 	 */
403 	switch (cdb[0]) {
404 	case INQUIRY:
405 	case LOG_SELECT:
406 	case LOG_SENSE:
407 	case MODE_SELECT:
408 	case MODE_SENSE:
409 	case REPORT_LUNS:
410 	case RECEIVE_DIAGNOSTIC:
411 	case SEND_DIAGNOSTIC:
412 		return 0;
413 	case MAINTENANCE_IN:
414 		switch (cdb[1] & 0x1f) {
415 		case MI_REPORT_TARGET_PGS:
416 			return 0;
417 		default:
418 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
419 			return 1;
420 		}
421 	case MAINTENANCE_OUT:
422 		switch (cdb[1]) {
423 		case MO_SET_TARGET_PGS:
424 			return 0;
425 		default:
426 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
427 			return 1;
428 		}
429 	case REQUEST_SENSE:
430 	case PERSISTENT_RESERVE_IN:
431 	case PERSISTENT_RESERVE_OUT:
432 	case READ_BUFFER:
433 	case WRITE_BUFFER:
434 		return 0;
435 	default:
436 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
437 		return 1;
438 	}
439 
440 	return 0;
441 }
442 
443 static inline int core_alua_state_unavailable(
444 	struct se_cmd *cmd,
445 	unsigned char *cdb,
446 	u8 *alua_ascq)
447 {
448 	/*
449 	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
450 	 * spc4r17 section 5.9.2.4.5
451 	 */
452 	switch (cdb[0]) {
453 	case INQUIRY:
454 	case REPORT_LUNS:
455 		return 0;
456 	case MAINTENANCE_IN:
457 		switch (cdb[1] & 0x1f) {
458 		case MI_REPORT_TARGET_PGS:
459 			return 0;
460 		default:
461 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
462 			return 1;
463 		}
464 	case MAINTENANCE_OUT:
465 		switch (cdb[1]) {
466 		case MO_SET_TARGET_PGS:
467 			return 0;
468 		default:
469 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
470 			return 1;
471 		}
472 	case REQUEST_SENSE:
473 	case READ_BUFFER:
474 	case WRITE_BUFFER:
475 		return 0;
476 	default:
477 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
478 		return 1;
479 	}
480 
481 	return 0;
482 }
483 
484 static inline int core_alua_state_transition(
485 	struct se_cmd *cmd,
486 	unsigned char *cdb,
487 	u8 *alua_ascq)
488 {
489 	/*
490 	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
491 	 * spc4r17 section 5.9.2.5
492 	 */
493 	switch (cdb[0]) {
494 	case INQUIRY:
495 	case REPORT_LUNS:
496 		return 0;
497 	case MAINTENANCE_IN:
498 		switch (cdb[1] & 0x1f) {
499 		case MI_REPORT_TARGET_PGS:
500 			return 0;
501 		default:
502 			*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
503 			return 1;
504 		}
505 	case REQUEST_SENSE:
506 	case READ_BUFFER:
507 	case WRITE_BUFFER:
508 		return 0;
509 	default:
510 		*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
511 		return 1;
512 	}
513 
514 	return 0;
515 }
516 
517 /*
518  * return 1: Is used to signal LUN not accecsable, and check condition/not ready
519  * return 0: Used to signal success
520  * reutrn -1: Used to signal failure, and invalid cdb field
521  */
522 sense_reason_t
523 target_alua_state_check(struct se_cmd *cmd)
524 {
525 	struct se_device *dev = cmd->se_dev;
526 	unsigned char *cdb = cmd->t_task_cdb;
527 	struct se_lun *lun = cmd->se_lun;
528 	struct se_port *port = lun->lun_sep;
529 	struct t10_alua_tg_pt_gp *tg_pt_gp;
530 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
531 	int out_alua_state, nonop_delay_msecs;
532 	u8 alua_ascq;
533 	int ret;
534 
535 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
536 		return 0;
537 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
538 		return 0;
539 
540 	if (!port)
541 		return 0;
542 	/*
543 	 * First, check for a struct se_port specific secondary ALUA target port
544 	 * access state: OFFLINE
545 	 */
546 	if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
547 		pr_debug("ALUA: Got secondary offline status for local"
548 				" target port\n");
549 		alua_ascq = ASCQ_04H_ALUA_OFFLINE;
550 		ret = 1;
551 		goto out;
552 	}
553 	 /*
554 	 * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
555 	 * ALUA target port group, to obtain current ALUA access state.
556 	 * Otherwise look for the underlying struct se_device association with
557 	 * a ALUA logical unit group.
558 	 */
559 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
560 	if (!tg_pt_gp_mem)
561 		return 0;
562 
563 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
564 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
565 	out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
566 	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
567 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
568 	/*
569 	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
570 	 * statement so the compiler knows explicitly to check this case first.
571 	 * For the Optimized ALUA access state case, we want to process the
572 	 * incoming fabric cmd ASAP..
573 	 */
574 	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
575 		return 0;
576 
577 	switch (out_alua_state) {
578 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
579 		ret = core_alua_state_nonoptimized(cmd, cdb,
580 					nonop_delay_msecs, &alua_ascq);
581 		break;
582 	case ALUA_ACCESS_STATE_STANDBY:
583 		ret = core_alua_state_standby(cmd, cdb, &alua_ascq);
584 		break;
585 	case ALUA_ACCESS_STATE_UNAVAILABLE:
586 		ret = core_alua_state_unavailable(cmd, cdb, &alua_ascq);
587 		break;
588 	case ALUA_ACCESS_STATE_TRANSITION:
589 		ret = core_alua_state_transition(cmd, cdb, &alua_ascq);
590 		break;
591 	/*
592 	 * OFFLINE is a secondary ALUA target port group access state, that is
593 	 * handled above with struct se_port->sep_tg_pt_secondary_offline=1
594 	 */
595 	case ALUA_ACCESS_STATE_OFFLINE:
596 	default:
597 		pr_err("Unknown ALUA access state: 0x%02x\n",
598 				out_alua_state);
599 		return TCM_INVALID_CDB_FIELD;
600 	}
601 
602 out:
603 	if (ret > 0) {
604 		/*
605 		 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
606 		 * The ALUA additional sense code qualifier (ASCQ) is determined
607 		 * by the ALUA primary or secondary access state..
608 		 */
609 		pr_debug("[%s]: ALUA TG Port not available, "
610 			"SenseKey: NOT_READY, ASC/ASCQ: "
611 			"0x04/0x%02x\n",
612 			cmd->se_tfo->get_fabric_name(), alua_ascq);
613 
614 		cmd->scsi_asc = 0x04;
615 		cmd->scsi_ascq = alua_ascq;
616 		return TCM_CHECK_CONDITION_NOT_READY;
617 	}
618 
619 	return 0;
620 }
621 
622 /*
623  * Check implict and explict ALUA state change request.
624  */
625 static sense_reason_t
626 core_alua_check_transition(int state, int *primary)
627 {
628 	switch (state) {
629 	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
630 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
631 	case ALUA_ACCESS_STATE_STANDBY:
632 	case ALUA_ACCESS_STATE_UNAVAILABLE:
633 		/*
634 		 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
635 		 * defined as primary target port asymmetric access states.
636 		 */
637 		*primary = 1;
638 		break;
639 	case ALUA_ACCESS_STATE_OFFLINE:
640 		/*
641 		 * OFFLINE state is defined as a secondary target port
642 		 * asymmetric access state.
643 		 */
644 		*primary = 0;
645 		break;
646 	default:
647 		pr_err("Unknown ALUA access state: 0x%02x\n", state);
648 		return TCM_INVALID_PARAMETER_LIST;
649 	}
650 
651 	return 0;
652 }
653 
654 static char *core_alua_dump_state(int state)
655 {
656 	switch (state) {
657 	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
658 		return "Active/Optimized";
659 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
660 		return "Active/NonOptimized";
661 	case ALUA_ACCESS_STATE_STANDBY:
662 		return "Standby";
663 	case ALUA_ACCESS_STATE_UNAVAILABLE:
664 		return "Unavailable";
665 	case ALUA_ACCESS_STATE_OFFLINE:
666 		return "Offline";
667 	default:
668 		return "Unknown";
669 	}
670 
671 	return NULL;
672 }
673 
674 char *core_alua_dump_status(int status)
675 {
676 	switch (status) {
677 	case ALUA_STATUS_NONE:
678 		return "None";
679 	case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
680 		return "Altered by Explict STPG";
681 	case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
682 		return "Altered by Implict ALUA";
683 	default:
684 		return "Unknown";
685 	}
686 
687 	return NULL;
688 }
689 
690 /*
691  * Used by fabric modules to determine when we need to delay processing
692  * for the Active/NonOptimized paths..
693  */
694 int core_alua_check_nonop_delay(
695 	struct se_cmd *cmd)
696 {
697 	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
698 		return 0;
699 	if (in_interrupt())
700 		return 0;
701 	/*
702 	 * The ALUA Active/NonOptimized access state delay can be disabled
703 	 * in via configfs with a value of zero
704 	 */
705 	if (!cmd->alua_nonop_delay)
706 		return 0;
707 	/*
708 	 * struct se_cmd->alua_nonop_delay gets set by a target port group
709 	 * defined interval in core_alua_state_nonoptimized()
710 	 */
711 	msleep_interruptible(cmd->alua_nonop_delay);
712 	return 0;
713 }
714 EXPORT_SYMBOL(core_alua_check_nonop_delay);
715 
716 /*
717  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
718  *
719  */
720 static int core_alua_write_tpg_metadata(
721 	const char *path,
722 	unsigned char *md_buf,
723 	u32 md_buf_len)
724 {
725 	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
726 	int ret;
727 
728 	if (IS_ERR(file)) {
729 		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
730 		return -ENODEV;
731 	}
732 	ret = kernel_write(file, md_buf, md_buf_len, 0);
733 	if (ret < 0)
734 		pr_err("Error writing ALUA metadata file: %s\n", path);
735 	fput(file);
736 	return (ret < 0) ? -EIO : 0;
737 }
738 
739 /*
740  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
741  */
742 static int core_alua_update_tpg_primary_metadata(
743 	struct t10_alua_tg_pt_gp *tg_pt_gp,
744 	int primary_state,
745 	unsigned char *md_buf)
746 {
747 	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
748 	char path[ALUA_METADATA_PATH_LEN];
749 	int len;
750 
751 	memset(path, 0, ALUA_METADATA_PATH_LEN);
752 
753 	len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
754 			"tg_pt_gp_id=%hu\n"
755 			"alua_access_state=0x%02x\n"
756 			"alua_access_status=0x%02x\n",
757 			tg_pt_gp->tg_pt_gp_id, primary_state,
758 			tg_pt_gp->tg_pt_gp_alua_access_status);
759 
760 	snprintf(path, ALUA_METADATA_PATH_LEN,
761 		"/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
762 		config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
763 
764 	return core_alua_write_tpg_metadata(path, md_buf, len);
765 }
766 
767 static int core_alua_do_transition_tg_pt(
768 	struct t10_alua_tg_pt_gp *tg_pt_gp,
769 	struct se_port *l_port,
770 	struct se_node_acl *nacl,
771 	unsigned char *md_buf,
772 	int new_state,
773 	int explict)
774 {
775 	struct se_dev_entry *se_deve;
776 	struct se_lun_acl *lacl;
777 	struct se_port *port;
778 	struct t10_alua_tg_pt_gp_member *mem;
779 	int old_state = 0;
780 	/*
781 	 * Save the old primary ALUA access state, and set the current state
782 	 * to ALUA_ACCESS_STATE_TRANSITION.
783 	 */
784 	old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
785 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
786 			ALUA_ACCESS_STATE_TRANSITION);
787 	tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
788 				ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
789 				ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
790 	/*
791 	 * Check for the optional ALUA primary state transition delay
792 	 */
793 	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
794 		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
795 
796 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
797 	list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
798 				tg_pt_gp_mem_list) {
799 		port = mem->tg_pt;
800 		/*
801 		 * After an implicit target port asymmetric access state
802 		 * change, a device server shall establish a unit attention
803 		 * condition for the initiator port associated with every I_T
804 		 * nexus with the additional sense code set to ASYMMETRIC
805 		 * ACCESS STATE CHAGED.
806 		 *
807 		 * After an explicit target port asymmetric access state
808 		 * change, a device server shall establish a unit attention
809 		 * condition with the additional sense code set to ASYMMETRIC
810 		 * ACCESS STATE CHANGED for the initiator port associated with
811 		 * every I_T nexus other than the I_T nexus on which the SET
812 		 * TARGET PORT GROUPS command
813 		 */
814 		atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
815 		smp_mb__after_atomic_inc();
816 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
817 
818 		spin_lock_bh(&port->sep_alua_lock);
819 		list_for_each_entry(se_deve, &port->sep_alua_list,
820 					alua_port_list) {
821 			lacl = se_deve->se_lun_acl;
822 			/*
823 			 * se_deve->se_lun_acl pointer may be NULL for a
824 			 * entry created without explict Node+MappedLUN ACLs
825 			 */
826 			if (!lacl)
827 				continue;
828 
829 			if (explict &&
830 			   (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
831 			   (l_port != NULL) && (l_port == port))
832 				continue;
833 
834 			core_scsi3_ua_allocate(lacl->se_lun_nacl,
835 				se_deve->mapped_lun, 0x2A,
836 				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
837 		}
838 		spin_unlock_bh(&port->sep_alua_lock);
839 
840 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
841 		atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
842 		smp_mb__after_atomic_dec();
843 	}
844 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
845 	/*
846 	 * Update the ALUA metadata buf that has been allocated in
847 	 * core_alua_do_port_transition(), this metadata will be written
848 	 * to struct file.
849 	 *
850 	 * Note that there is the case where we do not want to update the
851 	 * metadata when the saved metadata is being parsed in userspace
852 	 * when setting the existing port access state and access status.
853 	 *
854 	 * Also note that the failure to write out the ALUA metadata to
855 	 * struct file does NOT affect the actual ALUA transition.
856 	 */
857 	if (tg_pt_gp->tg_pt_gp_write_metadata) {
858 		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
859 		core_alua_update_tpg_primary_metadata(tg_pt_gp,
860 					new_state, md_buf);
861 		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
862 	}
863 	/*
864 	 * Set the current primary ALUA access state to the requested new state
865 	 */
866 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
867 
868 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
869 		" from primary access state %s to %s\n", (explict) ? "explict" :
870 		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
871 		tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
872 		core_alua_dump_state(new_state));
873 
874 	return 0;
875 }
876 
877 int core_alua_do_port_transition(
878 	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
879 	struct se_device *l_dev,
880 	struct se_port *l_port,
881 	struct se_node_acl *l_nacl,
882 	int new_state,
883 	int explict)
884 {
885 	struct se_device *dev;
886 	struct se_port *port;
887 	struct se_node_acl *nacl;
888 	struct t10_alua_lu_gp *lu_gp;
889 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
890 	struct t10_alua_tg_pt_gp *tg_pt_gp;
891 	unsigned char *md_buf;
892 	int primary;
893 
894 	if (core_alua_check_transition(new_state, &primary) != 0)
895 		return -EINVAL;
896 
897 	md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
898 	if (!md_buf) {
899 		pr_err("Unable to allocate buf for ALUA metadata\n");
900 		return -ENOMEM;
901 	}
902 
903 	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
904 	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
905 	lu_gp = local_lu_gp_mem->lu_gp;
906 	atomic_inc(&lu_gp->lu_gp_ref_cnt);
907 	smp_mb__after_atomic_inc();
908 	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
909 	/*
910 	 * For storage objects that are members of the 'default_lu_gp',
911 	 * we only do transition on the passed *l_tp_pt_gp, and not
912 	 * on all of the matching target port groups IDs in default_lu_gp.
913 	 */
914 	if (!lu_gp->lu_gp_id) {
915 		/*
916 		 * core_alua_do_transition_tg_pt() will always return
917 		 * success.
918 		 */
919 		core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
920 					md_buf, new_state, explict);
921 		atomic_dec(&lu_gp->lu_gp_ref_cnt);
922 		smp_mb__after_atomic_dec();
923 		kfree(md_buf);
924 		return 0;
925 	}
926 	/*
927 	 * For all other LU groups aside from 'default_lu_gp', walk all of
928 	 * the associated storage objects looking for a matching target port
929 	 * group ID from the local target port group.
930 	 */
931 	spin_lock(&lu_gp->lu_gp_lock);
932 	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
933 				lu_gp_mem_list) {
934 
935 		dev = lu_gp_mem->lu_gp_mem_dev;
936 		atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
937 		smp_mb__after_atomic_inc();
938 		spin_unlock(&lu_gp->lu_gp_lock);
939 
940 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
941 		list_for_each_entry(tg_pt_gp,
942 				&dev->t10_alua.tg_pt_gps_list,
943 				tg_pt_gp_list) {
944 
945 			if (!tg_pt_gp->tg_pt_gp_valid_id)
946 				continue;
947 			/*
948 			 * If the target behavior port asymmetric access state
949 			 * is changed for any target port group accessiable via
950 			 * a logical unit within a LU group, the target port
951 			 * behavior group asymmetric access states for the same
952 			 * target port group accessible via other logical units
953 			 * in that LU group will also change.
954 			 */
955 			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
956 				continue;
957 
958 			if (l_tg_pt_gp == tg_pt_gp) {
959 				port = l_port;
960 				nacl = l_nacl;
961 			} else {
962 				port = NULL;
963 				nacl = NULL;
964 			}
965 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
966 			smp_mb__after_atomic_inc();
967 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
968 			/*
969 			 * core_alua_do_transition_tg_pt() will always return
970 			 * success.
971 			 */
972 			core_alua_do_transition_tg_pt(tg_pt_gp, port,
973 					nacl, md_buf, new_state, explict);
974 
975 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
976 			atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
977 			smp_mb__after_atomic_dec();
978 		}
979 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
980 
981 		spin_lock(&lu_gp->lu_gp_lock);
982 		atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
983 		smp_mb__after_atomic_dec();
984 	}
985 	spin_unlock(&lu_gp->lu_gp_lock);
986 
987 	pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
988 		" Group IDs: %hu %s transition to primary state: %s\n",
989 		config_item_name(&lu_gp->lu_gp_group.cg_item),
990 		l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
991 		core_alua_dump_state(new_state));
992 
993 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
994 	smp_mb__after_atomic_dec();
995 	kfree(md_buf);
996 	return 0;
997 }
998 
999 /*
1000  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
1001  */
1002 static int core_alua_update_tpg_secondary_metadata(
1003 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1004 	struct se_port *port,
1005 	unsigned char *md_buf,
1006 	u32 md_buf_len)
1007 {
1008 	struct se_portal_group *se_tpg = port->sep_tpg;
1009 	char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1010 	int len;
1011 
1012 	memset(path, 0, ALUA_METADATA_PATH_LEN);
1013 	memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1014 
1015 	len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1016 			se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1017 
1018 	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1019 		snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1020 				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1021 
1022 	len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1023 			"alua_tg_pt_status=0x%02x\n",
1024 			atomic_read(&port->sep_tg_pt_secondary_offline),
1025 			port->sep_tg_pt_secondary_stat);
1026 
1027 	snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1028 			se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1029 			port->sep_lun->unpacked_lun);
1030 
1031 	return core_alua_write_tpg_metadata(path, md_buf, len);
1032 }
1033 
1034 static int core_alua_set_tg_pt_secondary_state(
1035 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1036 	struct se_port *port,
1037 	int explict,
1038 	int offline)
1039 {
1040 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1041 	unsigned char *md_buf;
1042 	u32 md_buf_len;
1043 	int trans_delay_msecs;
1044 
1045 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1046 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1047 	if (!tg_pt_gp) {
1048 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1049 		pr_err("Unable to complete secondary state"
1050 				" transition\n");
1051 		return -EINVAL;
1052 	}
1053 	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1054 	/*
1055 	 * Set the secondary ALUA target port access state to OFFLINE
1056 	 * or release the previously secondary state for struct se_port
1057 	 */
1058 	if (offline)
1059 		atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1060 	else
1061 		atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1062 
1063 	md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1064 	port->sep_tg_pt_secondary_stat = (explict) ?
1065 			ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1066 			ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1067 
1068 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1069 		" to secondary access state: %s\n", (explict) ? "explict" :
1070 		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1071 		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1072 
1073 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1074 	/*
1075 	 * Do the optional transition delay after we set the secondary
1076 	 * ALUA access state.
1077 	 */
1078 	if (trans_delay_msecs != 0)
1079 		msleep_interruptible(trans_delay_msecs);
1080 	/*
1081 	 * See if we need to update the ALUA fabric port metadata for
1082 	 * secondary state and status
1083 	 */
1084 	if (port->sep_tg_pt_secondary_write_md) {
1085 		md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1086 		if (!md_buf) {
1087 			pr_err("Unable to allocate md_buf for"
1088 				" secondary ALUA access metadata\n");
1089 			return -ENOMEM;
1090 		}
1091 		mutex_lock(&port->sep_tg_pt_md_mutex);
1092 		core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1093 				md_buf, md_buf_len);
1094 		mutex_unlock(&port->sep_tg_pt_md_mutex);
1095 
1096 		kfree(md_buf);
1097 	}
1098 
1099 	return 0;
1100 }
1101 
1102 struct t10_alua_lu_gp *
1103 core_alua_allocate_lu_gp(const char *name, int def_group)
1104 {
1105 	struct t10_alua_lu_gp *lu_gp;
1106 
1107 	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1108 	if (!lu_gp) {
1109 		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1110 		return ERR_PTR(-ENOMEM);
1111 	}
1112 	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1113 	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1114 	spin_lock_init(&lu_gp->lu_gp_lock);
1115 	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1116 
1117 	if (def_group) {
1118 		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1119 		lu_gp->lu_gp_valid_id = 1;
1120 		alua_lu_gps_count++;
1121 	}
1122 
1123 	return lu_gp;
1124 }
1125 
1126 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1127 {
1128 	struct t10_alua_lu_gp *lu_gp_tmp;
1129 	u16 lu_gp_id_tmp;
1130 	/*
1131 	 * The lu_gp->lu_gp_id may only be set once..
1132 	 */
1133 	if (lu_gp->lu_gp_valid_id) {
1134 		pr_warn("ALUA LU Group already has a valid ID,"
1135 			" ignoring request\n");
1136 		return -EINVAL;
1137 	}
1138 
1139 	spin_lock(&lu_gps_lock);
1140 	if (alua_lu_gps_count == 0x0000ffff) {
1141 		pr_err("Maximum ALUA alua_lu_gps_count:"
1142 				" 0x0000ffff reached\n");
1143 		spin_unlock(&lu_gps_lock);
1144 		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1145 		return -ENOSPC;
1146 	}
1147 again:
1148 	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1149 				alua_lu_gps_counter++;
1150 
1151 	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1152 		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1153 			if (!lu_gp_id)
1154 				goto again;
1155 
1156 			pr_warn("ALUA Logical Unit Group ID: %hu"
1157 				" already exists, ignoring request\n",
1158 				lu_gp_id);
1159 			spin_unlock(&lu_gps_lock);
1160 			return -EINVAL;
1161 		}
1162 	}
1163 
1164 	lu_gp->lu_gp_id = lu_gp_id_tmp;
1165 	lu_gp->lu_gp_valid_id = 1;
1166 	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1167 	alua_lu_gps_count++;
1168 	spin_unlock(&lu_gps_lock);
1169 
1170 	return 0;
1171 }
1172 
1173 static struct t10_alua_lu_gp_member *
1174 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1175 {
1176 	struct t10_alua_lu_gp_member *lu_gp_mem;
1177 
1178 	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1179 	if (!lu_gp_mem) {
1180 		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1181 		return ERR_PTR(-ENOMEM);
1182 	}
1183 	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1184 	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1185 	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1186 
1187 	lu_gp_mem->lu_gp_mem_dev = dev;
1188 	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1189 
1190 	return lu_gp_mem;
1191 }
1192 
1193 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1194 {
1195 	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1196 	/*
1197 	 * Once we have reached this point, config_item_put() has
1198 	 * already been called from target_core_alua_drop_lu_gp().
1199 	 *
1200 	 * Here, we remove the *lu_gp from the global list so that
1201 	 * no associations can be made while we are releasing
1202 	 * struct t10_alua_lu_gp.
1203 	 */
1204 	spin_lock(&lu_gps_lock);
1205 	list_del(&lu_gp->lu_gp_node);
1206 	alua_lu_gps_count--;
1207 	spin_unlock(&lu_gps_lock);
1208 	/*
1209 	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1210 	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1211 	 * released with core_alua_put_lu_gp_from_name()
1212 	 */
1213 	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1214 		cpu_relax();
1215 	/*
1216 	 * Release reference to struct t10_alua_lu_gp * from all associated
1217 	 * struct se_device.
1218 	 */
1219 	spin_lock(&lu_gp->lu_gp_lock);
1220 	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1221 				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1222 		if (lu_gp_mem->lu_gp_assoc) {
1223 			list_del(&lu_gp_mem->lu_gp_mem_list);
1224 			lu_gp->lu_gp_members--;
1225 			lu_gp_mem->lu_gp_assoc = 0;
1226 		}
1227 		spin_unlock(&lu_gp->lu_gp_lock);
1228 		/*
1229 		 *
1230 		 * lu_gp_mem is associated with a single
1231 		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1232 		 * struct se_device is released via core_alua_free_lu_gp_mem().
1233 		 *
1234 		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1235 		 * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1236 		 */
1237 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1238 		if (lu_gp != default_lu_gp)
1239 			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1240 					default_lu_gp);
1241 		else
1242 			lu_gp_mem->lu_gp = NULL;
1243 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1244 
1245 		spin_lock(&lu_gp->lu_gp_lock);
1246 	}
1247 	spin_unlock(&lu_gp->lu_gp_lock);
1248 
1249 	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1250 }
1251 
1252 void core_alua_free_lu_gp_mem(struct se_device *dev)
1253 {
1254 	struct t10_alua_lu_gp *lu_gp;
1255 	struct t10_alua_lu_gp_member *lu_gp_mem;
1256 
1257 	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1258 	if (!lu_gp_mem)
1259 		return;
1260 
1261 	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1262 		cpu_relax();
1263 
1264 	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1265 	lu_gp = lu_gp_mem->lu_gp;
1266 	if (lu_gp) {
1267 		spin_lock(&lu_gp->lu_gp_lock);
1268 		if (lu_gp_mem->lu_gp_assoc) {
1269 			list_del(&lu_gp_mem->lu_gp_mem_list);
1270 			lu_gp->lu_gp_members--;
1271 			lu_gp_mem->lu_gp_assoc = 0;
1272 		}
1273 		spin_unlock(&lu_gp->lu_gp_lock);
1274 		lu_gp_mem->lu_gp = NULL;
1275 	}
1276 	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1277 
1278 	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1279 }
1280 
1281 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1282 {
1283 	struct t10_alua_lu_gp *lu_gp;
1284 	struct config_item *ci;
1285 
1286 	spin_lock(&lu_gps_lock);
1287 	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1288 		if (!lu_gp->lu_gp_valid_id)
1289 			continue;
1290 		ci = &lu_gp->lu_gp_group.cg_item;
1291 		if (!strcmp(config_item_name(ci), name)) {
1292 			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1293 			spin_unlock(&lu_gps_lock);
1294 			return lu_gp;
1295 		}
1296 	}
1297 	spin_unlock(&lu_gps_lock);
1298 
1299 	return NULL;
1300 }
1301 
1302 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1303 {
1304 	spin_lock(&lu_gps_lock);
1305 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1306 	spin_unlock(&lu_gps_lock);
1307 }
1308 
1309 /*
1310  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1311  */
1312 void __core_alua_attach_lu_gp_mem(
1313 	struct t10_alua_lu_gp_member *lu_gp_mem,
1314 	struct t10_alua_lu_gp *lu_gp)
1315 {
1316 	spin_lock(&lu_gp->lu_gp_lock);
1317 	lu_gp_mem->lu_gp = lu_gp;
1318 	lu_gp_mem->lu_gp_assoc = 1;
1319 	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1320 	lu_gp->lu_gp_members++;
1321 	spin_unlock(&lu_gp->lu_gp_lock);
1322 }
1323 
1324 /*
1325  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1326  */
1327 void __core_alua_drop_lu_gp_mem(
1328 	struct t10_alua_lu_gp_member *lu_gp_mem,
1329 	struct t10_alua_lu_gp *lu_gp)
1330 {
1331 	spin_lock(&lu_gp->lu_gp_lock);
1332 	list_del(&lu_gp_mem->lu_gp_mem_list);
1333 	lu_gp_mem->lu_gp = NULL;
1334 	lu_gp_mem->lu_gp_assoc = 0;
1335 	lu_gp->lu_gp_members--;
1336 	spin_unlock(&lu_gp->lu_gp_lock);
1337 }
1338 
1339 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1340 		const char *name, int def_group)
1341 {
1342 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1343 
1344 	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1345 	if (!tg_pt_gp) {
1346 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1347 		return NULL;
1348 	}
1349 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1350 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1351 	mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1352 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1353 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1354 	tg_pt_gp->tg_pt_gp_dev = dev;
1355 	tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1356 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1357 		ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1358 	/*
1359 	 * Enable both explict and implict ALUA support by default
1360 	 */
1361 	tg_pt_gp->tg_pt_gp_alua_access_type =
1362 			TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1363 	/*
1364 	 * Set the default Active/NonOptimized Delay in milliseconds
1365 	 */
1366 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1367 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1368 	tg_pt_gp->tg_pt_gp_implict_trans_secs = ALUA_DEFAULT_IMPLICT_TRANS_SECS;
1369 
1370 	if (def_group) {
1371 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1372 		tg_pt_gp->tg_pt_gp_id =
1373 				dev->t10_alua.alua_tg_pt_gps_counter++;
1374 		tg_pt_gp->tg_pt_gp_valid_id = 1;
1375 		dev->t10_alua.alua_tg_pt_gps_count++;
1376 		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1377 			      &dev->t10_alua.tg_pt_gps_list);
1378 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1379 	}
1380 
1381 	return tg_pt_gp;
1382 }
1383 
1384 int core_alua_set_tg_pt_gp_id(
1385 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1386 	u16 tg_pt_gp_id)
1387 {
1388 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1389 	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1390 	u16 tg_pt_gp_id_tmp;
1391 
1392 	/*
1393 	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1394 	 */
1395 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1396 		pr_warn("ALUA TG PT Group already has a valid ID,"
1397 			" ignoring request\n");
1398 		return -EINVAL;
1399 	}
1400 
1401 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1402 	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1403 		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1404 			" 0x0000ffff reached\n");
1405 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1406 		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1407 		return -ENOSPC;
1408 	}
1409 again:
1410 	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1411 			dev->t10_alua.alua_tg_pt_gps_counter++;
1412 
1413 	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1414 			tg_pt_gp_list) {
1415 		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1416 			if (!tg_pt_gp_id)
1417 				goto again;
1418 
1419 			pr_err("ALUA Target Port Group ID: %hu already"
1420 				" exists, ignoring request\n", tg_pt_gp_id);
1421 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1422 			return -EINVAL;
1423 		}
1424 	}
1425 
1426 	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1427 	tg_pt_gp->tg_pt_gp_valid_id = 1;
1428 	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1429 			&dev->t10_alua.tg_pt_gps_list);
1430 	dev->t10_alua.alua_tg_pt_gps_count++;
1431 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1432 
1433 	return 0;
1434 }
1435 
1436 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1437 	struct se_port *port)
1438 {
1439 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1440 
1441 	tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1442 				GFP_KERNEL);
1443 	if (!tg_pt_gp_mem) {
1444 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1445 		return ERR_PTR(-ENOMEM);
1446 	}
1447 	INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1448 	spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1449 	atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1450 
1451 	tg_pt_gp_mem->tg_pt = port;
1452 	port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1453 
1454 	return tg_pt_gp_mem;
1455 }
1456 
1457 void core_alua_free_tg_pt_gp(
1458 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1459 {
1460 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1461 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1462 
1463 	/*
1464 	 * Once we have reached this point, config_item_put() has already
1465 	 * been called from target_core_alua_drop_tg_pt_gp().
1466 	 *
1467 	 * Here we remove *tg_pt_gp from the global list so that
1468 	 * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1469 	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1470 	 */
1471 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1472 	list_del(&tg_pt_gp->tg_pt_gp_list);
1473 	dev->t10_alua.alua_tg_pt_gps_counter--;
1474 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1475 
1476 	/*
1477 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1478 	 * core_alua_get_tg_pt_gp_by_name() in
1479 	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1480 	 * to be released with core_alua_put_tg_pt_gp_from_name().
1481 	 */
1482 	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1483 		cpu_relax();
1484 
1485 	/*
1486 	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1487 	 * struct se_port.
1488 	 */
1489 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1490 	list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1491 			&tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1492 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1493 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1494 			tg_pt_gp->tg_pt_gp_members--;
1495 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1496 		}
1497 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1498 		/*
1499 		 * tg_pt_gp_mem is associated with a single
1500 		 * se_port->sep_alua_tg_pt_gp_mem, and is released via
1501 		 * core_alua_free_tg_pt_gp_mem().
1502 		 *
1503 		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1504 		 * assume we want to re-assocate a given tg_pt_gp_mem with
1505 		 * default_tg_pt_gp.
1506 		 */
1507 		spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1508 		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1509 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1510 					dev->t10_alua.default_tg_pt_gp);
1511 		} else
1512 			tg_pt_gp_mem->tg_pt_gp = NULL;
1513 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1514 
1515 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1516 	}
1517 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1518 
1519 	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1520 }
1521 
1522 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1523 {
1524 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1525 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1526 
1527 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1528 	if (!tg_pt_gp_mem)
1529 		return;
1530 
1531 	while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1532 		cpu_relax();
1533 
1534 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1535 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1536 	if (tg_pt_gp) {
1537 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1538 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1539 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1540 			tg_pt_gp->tg_pt_gp_members--;
1541 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1542 		}
1543 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1544 		tg_pt_gp_mem->tg_pt_gp = NULL;
1545 	}
1546 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1547 
1548 	kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1549 }
1550 
1551 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1552 		struct se_device *dev, const char *name)
1553 {
1554 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1555 	struct config_item *ci;
1556 
1557 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1558 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1559 			tg_pt_gp_list) {
1560 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1561 			continue;
1562 		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1563 		if (!strcmp(config_item_name(ci), name)) {
1564 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1565 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1566 			return tg_pt_gp;
1567 		}
1568 	}
1569 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1570 
1571 	return NULL;
1572 }
1573 
1574 static void core_alua_put_tg_pt_gp_from_name(
1575 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1576 {
1577 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1578 
1579 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1580 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1581 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1582 }
1583 
1584 /*
1585  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1586  */
1587 void __core_alua_attach_tg_pt_gp_mem(
1588 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1589 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1590 {
1591 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1592 	tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1593 	tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1594 	list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1595 			&tg_pt_gp->tg_pt_gp_mem_list);
1596 	tg_pt_gp->tg_pt_gp_members++;
1597 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1598 }
1599 
1600 /*
1601  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1602  */
1603 static void __core_alua_drop_tg_pt_gp_mem(
1604 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1605 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1606 {
1607 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1608 	list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1609 	tg_pt_gp_mem->tg_pt_gp = NULL;
1610 	tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1611 	tg_pt_gp->tg_pt_gp_members--;
1612 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1613 }
1614 
1615 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1616 {
1617 	struct config_item *tg_pt_ci;
1618 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1619 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1620 	ssize_t len = 0;
1621 
1622 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1623 	if (!tg_pt_gp_mem)
1624 		return len;
1625 
1626 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1627 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1628 	if (tg_pt_gp) {
1629 		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1630 		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1631 			" %hu\nTG Port Primary Access State: %s\nTG Port "
1632 			"Primary Access Status: %s\nTG Port Secondary Access"
1633 			" State: %s\nTG Port Secondary Access Status: %s\n",
1634 			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1635 			core_alua_dump_state(atomic_read(
1636 					&tg_pt_gp->tg_pt_gp_alua_access_state)),
1637 			core_alua_dump_status(
1638 				tg_pt_gp->tg_pt_gp_alua_access_status),
1639 			(atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1640 			"Offline" : "None",
1641 			core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1642 	}
1643 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1644 
1645 	return len;
1646 }
1647 
1648 ssize_t core_alua_store_tg_pt_gp_info(
1649 	struct se_port *port,
1650 	const char *page,
1651 	size_t count)
1652 {
1653 	struct se_portal_group *tpg;
1654 	struct se_lun *lun;
1655 	struct se_device *dev = port->sep_lun->lun_se_dev;
1656 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1657 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1658 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1659 	int move = 0;
1660 
1661 	tpg = port->sep_tpg;
1662 	lun = port->sep_lun;
1663 
1664 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1665 	if (!tg_pt_gp_mem)
1666 		return 0;
1667 
1668 	if (count > TG_PT_GROUP_NAME_BUF) {
1669 		pr_err("ALUA Target Port Group alias too large!\n");
1670 		return -EINVAL;
1671 	}
1672 	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1673 	memcpy(buf, page, count);
1674 	/*
1675 	 * Any ALUA target port group alias besides "NULL" means we will be
1676 	 * making a new group association.
1677 	 */
1678 	if (strcmp(strstrip(buf), "NULL")) {
1679 		/*
1680 		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1681 		 * struct t10_alua_tg_pt_gp.  This reference is released with
1682 		 * core_alua_put_tg_pt_gp_from_name() below.
1683 		 */
1684 		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1685 					strstrip(buf));
1686 		if (!tg_pt_gp_new)
1687 			return -ENODEV;
1688 	}
1689 
1690 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1691 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1692 	if (tg_pt_gp) {
1693 		/*
1694 		 * Clearing an existing tg_pt_gp association, and replacing
1695 		 * with the default_tg_pt_gp.
1696 		 */
1697 		if (!tg_pt_gp_new) {
1698 			pr_debug("Target_Core_ConfigFS: Moving"
1699 				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
1700 				" alua/%s, ID: %hu back to"
1701 				" default_tg_pt_gp\n",
1702 				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1703 				tpg->se_tpg_tfo->tpg_get_tag(tpg),
1704 				config_item_name(&lun->lun_group.cg_item),
1705 				config_item_name(
1706 					&tg_pt_gp->tg_pt_gp_group.cg_item),
1707 				tg_pt_gp->tg_pt_gp_id);
1708 
1709 			__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1710 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1711 					dev->t10_alua.default_tg_pt_gp);
1712 			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1713 
1714 			return count;
1715 		}
1716 		/*
1717 		 * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1718 		 */
1719 		__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1720 		move = 1;
1721 	}
1722 	/*
1723 	 * Associate tg_pt_gp_mem with tg_pt_gp_new.
1724 	 */
1725 	__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1726 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1727 	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1728 		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
1729 		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1730 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
1731 		config_item_name(&lun->lun_group.cg_item),
1732 		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1733 		tg_pt_gp_new->tg_pt_gp_id);
1734 
1735 	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1736 	return count;
1737 }
1738 
1739 ssize_t core_alua_show_access_type(
1740 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1741 	char *page)
1742 {
1743 	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1744 	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1745 		return sprintf(page, "Implict and Explict\n");
1746 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1747 		return sprintf(page, "Implict\n");
1748 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1749 		return sprintf(page, "Explict\n");
1750 	else
1751 		return sprintf(page, "None\n");
1752 }
1753 
1754 ssize_t core_alua_store_access_type(
1755 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1756 	const char *page,
1757 	size_t count)
1758 {
1759 	unsigned long tmp;
1760 	int ret;
1761 
1762 	ret = kstrtoul(page, 0, &tmp);
1763 	if (ret < 0) {
1764 		pr_err("Unable to extract alua_access_type\n");
1765 		return ret;
1766 	}
1767 	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1768 		pr_err("Illegal value for alua_access_type:"
1769 				" %lu\n", tmp);
1770 		return -EINVAL;
1771 	}
1772 	if (tmp == 3)
1773 		tg_pt_gp->tg_pt_gp_alua_access_type =
1774 			TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1775 	else if (tmp == 2)
1776 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1777 	else if (tmp == 1)
1778 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1779 	else
1780 		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1781 
1782 	return count;
1783 }
1784 
1785 ssize_t core_alua_show_nonop_delay_msecs(
1786 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1787 	char *page)
1788 {
1789 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1790 }
1791 
1792 ssize_t core_alua_store_nonop_delay_msecs(
1793 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1794 	const char *page,
1795 	size_t count)
1796 {
1797 	unsigned long tmp;
1798 	int ret;
1799 
1800 	ret = kstrtoul(page, 0, &tmp);
1801 	if (ret < 0) {
1802 		pr_err("Unable to extract nonop_delay_msecs\n");
1803 		return ret;
1804 	}
1805 	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1806 		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1807 			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1808 			ALUA_MAX_NONOP_DELAY_MSECS);
1809 		return -EINVAL;
1810 	}
1811 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1812 
1813 	return count;
1814 }
1815 
1816 ssize_t core_alua_show_trans_delay_msecs(
1817 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1818 	char *page)
1819 {
1820 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1821 }
1822 
1823 ssize_t core_alua_store_trans_delay_msecs(
1824 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1825 	const char *page,
1826 	size_t count)
1827 {
1828 	unsigned long tmp;
1829 	int ret;
1830 
1831 	ret = kstrtoul(page, 0, &tmp);
1832 	if (ret < 0) {
1833 		pr_err("Unable to extract trans_delay_msecs\n");
1834 		return ret;
1835 	}
1836 	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1837 		pr_err("Passed trans_delay_msecs: %lu, exceeds"
1838 			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1839 			ALUA_MAX_TRANS_DELAY_MSECS);
1840 		return -EINVAL;
1841 	}
1842 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1843 
1844 	return count;
1845 }
1846 
1847 ssize_t core_alua_show_implict_trans_secs(
1848 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1849 	char *page)
1850 {
1851 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implict_trans_secs);
1852 }
1853 
1854 ssize_t core_alua_store_implict_trans_secs(
1855 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1856 	const char *page,
1857 	size_t count)
1858 {
1859 	unsigned long tmp;
1860 	int ret;
1861 
1862 	ret = kstrtoul(page, 0, &tmp);
1863 	if (ret < 0) {
1864 		pr_err("Unable to extract implict_trans_secs\n");
1865 		return ret;
1866 	}
1867 	if (tmp > ALUA_MAX_IMPLICT_TRANS_SECS) {
1868 		pr_err("Passed implict_trans_secs: %lu, exceeds"
1869 			" ALUA_MAX_IMPLICT_TRANS_SECS: %d\n", tmp,
1870 			ALUA_MAX_IMPLICT_TRANS_SECS);
1871 		return  -EINVAL;
1872 	}
1873 	tg_pt_gp->tg_pt_gp_implict_trans_secs = (int)tmp;
1874 
1875 	return count;
1876 }
1877 
1878 ssize_t core_alua_show_preferred_bit(
1879 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1880 	char *page)
1881 {
1882 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1883 }
1884 
1885 ssize_t core_alua_store_preferred_bit(
1886 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1887 	const char *page,
1888 	size_t count)
1889 {
1890 	unsigned long tmp;
1891 	int ret;
1892 
1893 	ret = kstrtoul(page, 0, &tmp);
1894 	if (ret < 0) {
1895 		pr_err("Unable to extract preferred ALUA value\n");
1896 		return ret;
1897 	}
1898 	if ((tmp != 0) && (tmp != 1)) {
1899 		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1900 		return -EINVAL;
1901 	}
1902 	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1903 
1904 	return count;
1905 }
1906 
1907 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1908 {
1909 	if (!lun->lun_sep)
1910 		return -ENODEV;
1911 
1912 	return sprintf(page, "%d\n",
1913 		atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1914 }
1915 
1916 ssize_t core_alua_store_offline_bit(
1917 	struct se_lun *lun,
1918 	const char *page,
1919 	size_t count)
1920 {
1921 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1922 	unsigned long tmp;
1923 	int ret;
1924 
1925 	if (!lun->lun_sep)
1926 		return -ENODEV;
1927 
1928 	ret = kstrtoul(page, 0, &tmp);
1929 	if (ret < 0) {
1930 		pr_err("Unable to extract alua_tg_pt_offline value\n");
1931 		return ret;
1932 	}
1933 	if ((tmp != 0) && (tmp != 1)) {
1934 		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1935 				tmp);
1936 		return -EINVAL;
1937 	}
1938 	tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1939 	if (!tg_pt_gp_mem) {
1940 		pr_err("Unable to locate *tg_pt_gp_mem\n");
1941 		return -EINVAL;
1942 	}
1943 
1944 	ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1945 			lun->lun_sep, 0, (int)tmp);
1946 	if (ret < 0)
1947 		return -EINVAL;
1948 
1949 	return count;
1950 }
1951 
1952 ssize_t core_alua_show_secondary_status(
1953 	struct se_lun *lun,
1954 	char *page)
1955 {
1956 	return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1957 }
1958 
1959 ssize_t core_alua_store_secondary_status(
1960 	struct se_lun *lun,
1961 	const char *page,
1962 	size_t count)
1963 {
1964 	unsigned long tmp;
1965 	int ret;
1966 
1967 	ret = kstrtoul(page, 0, &tmp);
1968 	if (ret < 0) {
1969 		pr_err("Unable to extract alua_tg_pt_status\n");
1970 		return ret;
1971 	}
1972 	if ((tmp != ALUA_STATUS_NONE) &&
1973 	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
1974 	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
1975 		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
1976 				tmp);
1977 		return -EINVAL;
1978 	}
1979 	lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
1980 
1981 	return count;
1982 }
1983 
1984 ssize_t core_alua_show_secondary_write_metadata(
1985 	struct se_lun *lun,
1986 	char *page)
1987 {
1988 	return sprintf(page, "%d\n",
1989 			lun->lun_sep->sep_tg_pt_secondary_write_md);
1990 }
1991 
1992 ssize_t core_alua_store_secondary_write_metadata(
1993 	struct se_lun *lun,
1994 	const char *page,
1995 	size_t count)
1996 {
1997 	unsigned long tmp;
1998 	int ret;
1999 
2000 	ret = kstrtoul(page, 0, &tmp);
2001 	if (ret < 0) {
2002 		pr_err("Unable to extract alua_tg_pt_write_md\n");
2003 		return ret;
2004 	}
2005 	if ((tmp != 0) && (tmp != 1)) {
2006 		pr_err("Illegal value for alua_tg_pt_write_md:"
2007 				" %lu\n", tmp);
2008 		return -EINVAL;
2009 	}
2010 	lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
2011 
2012 	return count;
2013 }
2014 
2015 int core_setup_alua(struct se_device *dev)
2016 {
2017 	if (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV &&
2018 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2019 		struct t10_alua_lu_gp_member *lu_gp_mem;
2020 
2021 		/*
2022 		 * Associate this struct se_device with the default ALUA
2023 		 * LUN Group.
2024 		 */
2025 		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2026 		if (IS_ERR(lu_gp_mem))
2027 			return PTR_ERR(lu_gp_mem);
2028 
2029 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2030 		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2031 				default_lu_gp);
2032 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2033 
2034 		pr_debug("%s: Adding to default ALUA LU Group:"
2035 			" core/alua/lu_gps/default_lu_gp\n",
2036 			dev->transport->name);
2037 	}
2038 
2039 	return 0;
2040 }
2041