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 explicit, 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++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
121 		/*
122 		 * TARGET PORT GROUP
123 		 */
124 		buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
125 		buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
126 
127 		off++; /* Skip over Reserved */
128 		/*
129 		 * STATUS CODE
130 		 */
131 		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
132 		/*
133 		 * Vendor Specific field
134 		 */
135 		buf[off++] = 0x00;
136 		/*
137 		 * TARGET PORT COUNT
138 		 */
139 		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
140 		rd_len += 8;
141 
142 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
143 		list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
144 				tg_pt_gp_mem_list) {
145 			port = tg_pt_gp_mem->tg_pt;
146 			/*
147 			 * Start Target Port descriptor format
148 			 *
149 			 * See spc4r17 section 6.2.7 Table 247
150 			 */
151 			off += 2; /* Skip over Obsolete */
152 			/*
153 			 * Set RELATIVE TARGET PORT IDENTIFIER
154 			 */
155 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
156 			buf[off++] = (port->sep_rtpi & 0xff);
157 			rd_len += 4;
158 		}
159 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
160 	}
161 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
162 	/*
163 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
164 	 */
165 	put_unaligned_be32(rd_len, &buf[0]);
166 
167 	/*
168 	 * Fill in the Extended header parameter data format if requested
169 	 */
170 	if (ext_hdr != 0) {
171 		buf[4] = 0x10;
172 		/*
173 		 * Set the implicit transition time (in seconds) for the application
174 		 * client to use as a base for it's transition timeout value.
175 		 *
176 		 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
177 		 * this CDB was received upon to determine this value individually
178 		 * for ALUA target port group.
179 		 */
180 		port = cmd->se_lun->lun_sep;
181 		tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
182 		if (tg_pt_gp_mem) {
183 			spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
184 			tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
185 			if (tg_pt_gp)
186 				buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
187 			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
188 		}
189 	}
190 	transport_kunmap_data_sg(cmd);
191 
192 	target_complete_cmd(cmd, GOOD);
193 	return 0;
194 }
195 
196 /*
197  * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
198  *
199  * See spc4r17 section 6.35
200  */
201 sense_reason_t
202 target_emulate_set_target_port_groups(struct se_cmd *cmd)
203 {
204 	struct se_device *dev = cmd->se_dev;
205 	struct se_port *port, *l_port = cmd->se_lun->lun_sep;
206 	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
207 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
208 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
209 	unsigned char *buf;
210 	unsigned char *ptr;
211 	sense_reason_t rc = TCM_NO_SENSE;
212 	u32 len = 4; /* Skip over RESERVED area in header */
213 	int alua_access_state, primary = 0;
214 	u16 tg_pt_id, rtpi;
215 
216 	if (!l_port)
217 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
218 
219 	if (cmd->data_length < 4) {
220 		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
221 			" small\n", cmd->data_length);
222 		return TCM_INVALID_PARAMETER_LIST;
223 	}
224 
225 	buf = transport_kmap_data_sg(cmd);
226 	if (!buf)
227 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
228 
229 	/*
230 	 * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
231 	 * for the local tg_pt_gp.
232 	 */
233 	l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
234 	if (!l_tg_pt_gp_mem) {
235 		pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
236 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
237 		goto out;
238 	}
239 	spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
240 	l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
241 	if (!l_tg_pt_gp) {
242 		spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
243 		pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
244 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
245 		goto out;
246 	}
247 	spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
248 
249 	if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
250 		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
251 				" while TPGS_EXPLICIT_ALUA is disabled\n");
252 		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
253 		goto out;
254 	}
255 
256 	ptr = &buf[4]; /* Skip over RESERVED area in header */
257 
258 	while (len < cmd->data_length) {
259 		bool found = false;
260 		alua_access_state = (ptr[0] & 0x0f);
261 		/*
262 		 * Check the received ALUA access state, and determine if
263 		 * the state is a primary or secondary target port asymmetric
264 		 * access state.
265 		 */
266 		rc = core_alua_check_transition(alua_access_state, &primary);
267 		if (rc) {
268 			/*
269 			 * If the SET TARGET PORT GROUPS attempts to establish
270 			 * an invalid combination of target port asymmetric
271 			 * access states or attempts to establish an
272 			 * unsupported target port asymmetric access state,
273 			 * then the command shall be terminated with CHECK
274 			 * CONDITION status, with the sense key set to ILLEGAL
275 			 * REQUEST, and the additional sense code set to INVALID
276 			 * FIELD IN PARAMETER LIST.
277 			 */
278 			goto out;
279 		}
280 
281 		/*
282 		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
283 		 * specifies a primary target port asymmetric access state,
284 		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
285 		 * a primary target port group for which the primary target
286 		 * port asymmetric access state shall be changed. If the
287 		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
288 		 * port asymmetric access state, then the TARGET PORT GROUP OR
289 		 * TARGET PORT field specifies the relative target port
290 		 * identifier (see 3.1.120) of the target port for which the
291 		 * secondary target port asymmetric access state shall be
292 		 * changed.
293 		 */
294 		if (primary) {
295 			tg_pt_id = get_unaligned_be16(ptr + 2);
296 			/*
297 			 * Locate the matching target port group ID from
298 			 * the global tg_pt_gp list
299 			 */
300 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
301 			list_for_each_entry(tg_pt_gp,
302 					&dev->t10_alua.tg_pt_gps_list,
303 					tg_pt_gp_list) {
304 				if (!tg_pt_gp->tg_pt_gp_valid_id)
305 					continue;
306 
307 				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
308 					continue;
309 
310 				atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
311 				smp_mb__after_atomic_inc();
312 
313 				spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
314 
315 				if (!core_alua_do_port_transition(tg_pt_gp,
316 						dev, l_port, nacl,
317 						alua_access_state, 1))
318 					found = true;
319 
320 				spin_lock(&dev->t10_alua.tg_pt_gps_lock);
321 				atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
322 				smp_mb__after_atomic_dec();
323 				break;
324 			}
325 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
326 		} else {
327 			/*
328 			 * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
329 			 * the Target Port in question for the the incoming
330 			 * SET_TARGET_PORT_GROUPS op.
331 			 */
332 			rtpi = get_unaligned_be16(ptr + 2);
333 			/*
334 			 * Locate the matching relative target port identifier
335 			 * for the struct se_device storage object.
336 			 */
337 			spin_lock(&dev->se_port_lock);
338 			list_for_each_entry(port, &dev->dev_sep_list,
339 							sep_list) {
340 				if (port->sep_rtpi != rtpi)
341 					continue;
342 
343 				tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
344 
345 				spin_unlock(&dev->se_port_lock);
346 
347 				if (!core_alua_set_tg_pt_secondary_state(
348 						tg_pt_gp_mem, port, 1, 1))
349 					found = true;
350 
351 				spin_lock(&dev->se_port_lock);
352 				break;
353 			}
354 			spin_unlock(&dev->se_port_lock);
355 		}
356 
357 		if (!found) {
358 			rc = TCM_INVALID_PARAMETER_LIST;
359 			goto out;
360 		}
361 
362 		ptr += 4;
363 		len += 4;
364 	}
365 
366 out:
367 	transport_kunmap_data_sg(cmd);
368 	if (!rc)
369 		target_complete_cmd(cmd, GOOD);
370 	return rc;
371 }
372 
373 static inline int core_alua_state_nonoptimized(
374 	struct se_cmd *cmd,
375 	unsigned char *cdb,
376 	int nonop_delay_msecs,
377 	u8 *alua_ascq)
378 {
379 	/*
380 	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
381 	 * later to determine if processing of this cmd needs to be
382 	 * temporarily delayed for the Active/NonOptimized primary access state.
383 	 */
384 	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
385 	cmd->alua_nonop_delay = nonop_delay_msecs;
386 	return 0;
387 }
388 
389 static inline int core_alua_state_standby(
390 	struct se_cmd *cmd,
391 	unsigned char *cdb,
392 	u8 *alua_ascq)
393 {
394 	/*
395 	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
396 	 * spc4r17 section 5.9.2.4.4
397 	 */
398 	switch (cdb[0]) {
399 	case INQUIRY:
400 	case LOG_SELECT:
401 	case LOG_SENSE:
402 	case MODE_SELECT:
403 	case MODE_SENSE:
404 	case REPORT_LUNS:
405 	case RECEIVE_DIAGNOSTIC:
406 	case SEND_DIAGNOSTIC:
407 		return 0;
408 	case MAINTENANCE_IN:
409 		switch (cdb[1] & 0x1f) {
410 		case MI_REPORT_TARGET_PGS:
411 			return 0;
412 		default:
413 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
414 			return 1;
415 		}
416 	case MAINTENANCE_OUT:
417 		switch (cdb[1]) {
418 		case MO_SET_TARGET_PGS:
419 			return 0;
420 		default:
421 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
422 			return 1;
423 		}
424 	case REQUEST_SENSE:
425 	case PERSISTENT_RESERVE_IN:
426 	case PERSISTENT_RESERVE_OUT:
427 	case READ_BUFFER:
428 	case WRITE_BUFFER:
429 		return 0;
430 	default:
431 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
432 		return 1;
433 	}
434 
435 	return 0;
436 }
437 
438 static inline int core_alua_state_unavailable(
439 	struct se_cmd *cmd,
440 	unsigned char *cdb,
441 	u8 *alua_ascq)
442 {
443 	/*
444 	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
445 	 * spc4r17 section 5.9.2.4.5
446 	 */
447 	switch (cdb[0]) {
448 	case INQUIRY:
449 	case REPORT_LUNS:
450 		return 0;
451 	case MAINTENANCE_IN:
452 		switch (cdb[1] & 0x1f) {
453 		case MI_REPORT_TARGET_PGS:
454 			return 0;
455 		default:
456 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
457 			return 1;
458 		}
459 	case MAINTENANCE_OUT:
460 		switch (cdb[1]) {
461 		case MO_SET_TARGET_PGS:
462 			return 0;
463 		default:
464 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
465 			return 1;
466 		}
467 	case REQUEST_SENSE:
468 	case READ_BUFFER:
469 	case WRITE_BUFFER:
470 		return 0;
471 	default:
472 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
473 		return 1;
474 	}
475 
476 	return 0;
477 }
478 
479 static inline int core_alua_state_transition(
480 	struct se_cmd *cmd,
481 	unsigned char *cdb,
482 	u8 *alua_ascq)
483 {
484 	/*
485 	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
486 	 * spc4r17 section 5.9.2.5
487 	 */
488 	switch (cdb[0]) {
489 	case INQUIRY:
490 	case REPORT_LUNS:
491 		return 0;
492 	case MAINTENANCE_IN:
493 		switch (cdb[1] & 0x1f) {
494 		case MI_REPORT_TARGET_PGS:
495 			return 0;
496 		default:
497 			*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
498 			return 1;
499 		}
500 	case REQUEST_SENSE:
501 	case READ_BUFFER:
502 	case WRITE_BUFFER:
503 		return 0;
504 	default:
505 		*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
506 		return 1;
507 	}
508 
509 	return 0;
510 }
511 
512 /*
513  * return 1: Is used to signal LUN not accessible, and check condition/not ready
514  * return 0: Used to signal success
515  * return -1: Used to signal failure, and invalid cdb field
516  */
517 sense_reason_t
518 target_alua_state_check(struct se_cmd *cmd)
519 {
520 	struct se_device *dev = cmd->se_dev;
521 	unsigned char *cdb = cmd->t_task_cdb;
522 	struct se_lun *lun = cmd->se_lun;
523 	struct se_port *port = lun->lun_sep;
524 	struct t10_alua_tg_pt_gp *tg_pt_gp;
525 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
526 	int out_alua_state, nonop_delay_msecs;
527 	u8 alua_ascq;
528 	int ret;
529 
530 	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
531 		return 0;
532 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
533 		return 0;
534 
535 	if (!port)
536 		return 0;
537 	/*
538 	 * First, check for a struct se_port specific secondary ALUA target port
539 	 * access state: OFFLINE
540 	 */
541 	if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
542 		pr_debug("ALUA: Got secondary offline status for local"
543 				" target port\n");
544 		alua_ascq = ASCQ_04H_ALUA_OFFLINE;
545 		ret = 1;
546 		goto out;
547 	}
548 	 /*
549 	 * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
550 	 * ALUA target port group, to obtain current ALUA access state.
551 	 * Otherwise look for the underlying struct se_device association with
552 	 * a ALUA logical unit group.
553 	 */
554 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
555 	if (!tg_pt_gp_mem)
556 		return 0;
557 
558 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
559 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
560 	out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
561 	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
562 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
563 	/*
564 	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
565 	 * statement so the compiler knows explicitly to check this case first.
566 	 * For the Optimized ALUA access state case, we want to process the
567 	 * incoming fabric cmd ASAP..
568 	 */
569 	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
570 		return 0;
571 
572 	switch (out_alua_state) {
573 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
574 		ret = core_alua_state_nonoptimized(cmd, cdb,
575 					nonop_delay_msecs, &alua_ascq);
576 		break;
577 	case ALUA_ACCESS_STATE_STANDBY:
578 		ret = core_alua_state_standby(cmd, cdb, &alua_ascq);
579 		break;
580 	case ALUA_ACCESS_STATE_UNAVAILABLE:
581 		ret = core_alua_state_unavailable(cmd, cdb, &alua_ascq);
582 		break;
583 	case ALUA_ACCESS_STATE_TRANSITION:
584 		ret = core_alua_state_transition(cmd, cdb, &alua_ascq);
585 		break;
586 	/*
587 	 * OFFLINE is a secondary ALUA target port group access state, that is
588 	 * handled above with struct se_port->sep_tg_pt_secondary_offline=1
589 	 */
590 	case ALUA_ACCESS_STATE_OFFLINE:
591 	default:
592 		pr_err("Unknown ALUA access state: 0x%02x\n",
593 				out_alua_state);
594 		return TCM_INVALID_CDB_FIELD;
595 	}
596 
597 out:
598 	if (ret > 0) {
599 		/*
600 		 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
601 		 * The ALUA additional sense code qualifier (ASCQ) is determined
602 		 * by the ALUA primary or secondary access state..
603 		 */
604 		pr_debug("[%s]: ALUA TG Port not available, "
605 			"SenseKey: NOT_READY, ASC/ASCQ: "
606 			"0x04/0x%02x\n",
607 			cmd->se_tfo->get_fabric_name(), alua_ascq);
608 
609 		cmd->scsi_asc = 0x04;
610 		cmd->scsi_ascq = alua_ascq;
611 		return TCM_CHECK_CONDITION_NOT_READY;
612 	}
613 
614 	return 0;
615 }
616 
617 /*
618  * Check implicit and explicit ALUA state change request.
619  */
620 static sense_reason_t
621 core_alua_check_transition(int state, int *primary)
622 {
623 	switch (state) {
624 	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
625 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
626 	case ALUA_ACCESS_STATE_STANDBY:
627 	case ALUA_ACCESS_STATE_UNAVAILABLE:
628 		/*
629 		 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
630 		 * defined as primary target port asymmetric access states.
631 		 */
632 		*primary = 1;
633 		break;
634 	case ALUA_ACCESS_STATE_OFFLINE:
635 		/*
636 		 * OFFLINE state is defined as a secondary target port
637 		 * asymmetric access state.
638 		 */
639 		*primary = 0;
640 		break;
641 	default:
642 		pr_err("Unknown ALUA access state: 0x%02x\n", state);
643 		return TCM_INVALID_PARAMETER_LIST;
644 	}
645 
646 	return 0;
647 }
648 
649 static char *core_alua_dump_state(int state)
650 {
651 	switch (state) {
652 	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
653 		return "Active/Optimized";
654 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
655 		return "Active/NonOptimized";
656 	case ALUA_ACCESS_STATE_STANDBY:
657 		return "Standby";
658 	case ALUA_ACCESS_STATE_UNAVAILABLE:
659 		return "Unavailable";
660 	case ALUA_ACCESS_STATE_OFFLINE:
661 		return "Offline";
662 	default:
663 		return "Unknown";
664 	}
665 
666 	return NULL;
667 }
668 
669 char *core_alua_dump_status(int status)
670 {
671 	switch (status) {
672 	case ALUA_STATUS_NONE:
673 		return "None";
674 	case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
675 		return "Altered by Explicit STPG";
676 	case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
677 		return "Altered by Implicit ALUA";
678 	default:
679 		return "Unknown";
680 	}
681 
682 	return NULL;
683 }
684 
685 /*
686  * Used by fabric modules to determine when we need to delay processing
687  * for the Active/NonOptimized paths..
688  */
689 int core_alua_check_nonop_delay(
690 	struct se_cmd *cmd)
691 {
692 	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
693 		return 0;
694 	if (in_interrupt())
695 		return 0;
696 	/*
697 	 * The ALUA Active/NonOptimized access state delay can be disabled
698 	 * in via configfs with a value of zero
699 	 */
700 	if (!cmd->alua_nonop_delay)
701 		return 0;
702 	/*
703 	 * struct se_cmd->alua_nonop_delay gets set by a target port group
704 	 * defined interval in core_alua_state_nonoptimized()
705 	 */
706 	msleep_interruptible(cmd->alua_nonop_delay);
707 	return 0;
708 }
709 EXPORT_SYMBOL(core_alua_check_nonop_delay);
710 
711 /*
712  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
713  *
714  */
715 static int core_alua_write_tpg_metadata(
716 	const char *path,
717 	unsigned char *md_buf,
718 	u32 md_buf_len)
719 {
720 	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
721 	int ret;
722 
723 	if (IS_ERR(file)) {
724 		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
725 		return -ENODEV;
726 	}
727 	ret = kernel_write(file, md_buf, md_buf_len, 0);
728 	if (ret < 0)
729 		pr_err("Error writing ALUA metadata file: %s\n", path);
730 	fput(file);
731 	return (ret < 0) ? -EIO : 0;
732 }
733 
734 /*
735  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
736  */
737 static int core_alua_update_tpg_primary_metadata(
738 	struct t10_alua_tg_pt_gp *tg_pt_gp,
739 	int primary_state,
740 	unsigned char *md_buf)
741 {
742 	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
743 	char path[ALUA_METADATA_PATH_LEN];
744 	int len;
745 
746 	memset(path, 0, ALUA_METADATA_PATH_LEN);
747 
748 	len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
749 			"tg_pt_gp_id=%hu\n"
750 			"alua_access_state=0x%02x\n"
751 			"alua_access_status=0x%02x\n",
752 			tg_pt_gp->tg_pt_gp_id, primary_state,
753 			tg_pt_gp->tg_pt_gp_alua_access_status);
754 
755 	snprintf(path, ALUA_METADATA_PATH_LEN,
756 		"/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
757 		config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
758 
759 	return core_alua_write_tpg_metadata(path, md_buf, len);
760 }
761 
762 static int core_alua_do_transition_tg_pt(
763 	struct t10_alua_tg_pt_gp *tg_pt_gp,
764 	struct se_port *l_port,
765 	struct se_node_acl *nacl,
766 	unsigned char *md_buf,
767 	int new_state,
768 	int explicit)
769 {
770 	struct se_dev_entry *se_deve;
771 	struct se_lun_acl *lacl;
772 	struct se_port *port;
773 	struct t10_alua_tg_pt_gp_member *mem;
774 	int old_state = 0;
775 	/*
776 	 * Save the old primary ALUA access state, and set the current state
777 	 * to ALUA_ACCESS_STATE_TRANSITION.
778 	 */
779 	old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
780 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
781 			ALUA_ACCESS_STATE_TRANSITION);
782 	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
783 				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
784 				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
785 	/*
786 	 * Check for the optional ALUA primary state transition delay
787 	 */
788 	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
789 		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
790 
791 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
792 	list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
793 				tg_pt_gp_mem_list) {
794 		port = mem->tg_pt;
795 		/*
796 		 * After an implicit target port asymmetric access state
797 		 * change, a device server shall establish a unit attention
798 		 * condition for the initiator port associated with every I_T
799 		 * nexus with the additional sense code set to ASYMMETRIC
800 		 * ACCESS STATE CHANGED.
801 		 *
802 		 * After an explicit target port asymmetric access state
803 		 * change, a device server shall establish a unit attention
804 		 * condition with the additional sense code set to ASYMMETRIC
805 		 * ACCESS STATE CHANGED for the initiator port associated with
806 		 * every I_T nexus other than the I_T nexus on which the SET
807 		 * TARGET PORT GROUPS command
808 		 */
809 		atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
810 		smp_mb__after_atomic_inc();
811 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
812 
813 		spin_lock_bh(&port->sep_alua_lock);
814 		list_for_each_entry(se_deve, &port->sep_alua_list,
815 					alua_port_list) {
816 			lacl = se_deve->se_lun_acl;
817 			/*
818 			 * se_deve->se_lun_acl pointer may be NULL for a
819 			 * entry created without explicit Node+MappedLUN ACLs
820 			 */
821 			if (!lacl)
822 				continue;
823 
824 			if (explicit &&
825 			   (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
826 			   (l_port != NULL) && (l_port == port))
827 				continue;
828 
829 			core_scsi3_ua_allocate(lacl->se_lun_nacl,
830 				se_deve->mapped_lun, 0x2A,
831 				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
832 		}
833 		spin_unlock_bh(&port->sep_alua_lock);
834 
835 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
836 		atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
837 		smp_mb__after_atomic_dec();
838 	}
839 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
840 	/*
841 	 * Update the ALUA metadata buf that has been allocated in
842 	 * core_alua_do_port_transition(), this metadata will be written
843 	 * to struct file.
844 	 *
845 	 * Note that there is the case where we do not want to update the
846 	 * metadata when the saved metadata is being parsed in userspace
847 	 * when setting the existing port access state and access status.
848 	 *
849 	 * Also note that the failure to write out the ALUA metadata to
850 	 * struct file does NOT affect the actual ALUA transition.
851 	 */
852 	if (tg_pt_gp->tg_pt_gp_write_metadata) {
853 		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
854 		core_alua_update_tpg_primary_metadata(tg_pt_gp,
855 					new_state, md_buf);
856 		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
857 	}
858 	/*
859 	 * Set the current primary ALUA access state to the requested new state
860 	 */
861 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
862 
863 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
864 		" from primary access state %s to %s\n", (explicit) ? "explicit" :
865 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
866 		tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
867 		core_alua_dump_state(new_state));
868 
869 	return 0;
870 }
871 
872 int core_alua_do_port_transition(
873 	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
874 	struct se_device *l_dev,
875 	struct se_port *l_port,
876 	struct se_node_acl *l_nacl,
877 	int new_state,
878 	int explicit)
879 {
880 	struct se_device *dev;
881 	struct se_port *port;
882 	struct se_node_acl *nacl;
883 	struct t10_alua_lu_gp *lu_gp;
884 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
885 	struct t10_alua_tg_pt_gp *tg_pt_gp;
886 	unsigned char *md_buf;
887 	int primary;
888 
889 	if (core_alua_check_transition(new_state, &primary) != 0)
890 		return -EINVAL;
891 
892 	md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
893 	if (!md_buf) {
894 		pr_err("Unable to allocate buf for ALUA metadata\n");
895 		return -ENOMEM;
896 	}
897 
898 	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
899 	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
900 	lu_gp = local_lu_gp_mem->lu_gp;
901 	atomic_inc(&lu_gp->lu_gp_ref_cnt);
902 	smp_mb__after_atomic_inc();
903 	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
904 	/*
905 	 * For storage objects that are members of the 'default_lu_gp',
906 	 * we only do transition on the passed *l_tp_pt_gp, and not
907 	 * on all of the matching target port groups IDs in default_lu_gp.
908 	 */
909 	if (!lu_gp->lu_gp_id) {
910 		/*
911 		 * core_alua_do_transition_tg_pt() will always return
912 		 * success.
913 		 */
914 		core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
915 					md_buf, new_state, explicit);
916 		atomic_dec(&lu_gp->lu_gp_ref_cnt);
917 		smp_mb__after_atomic_dec();
918 		kfree(md_buf);
919 		return 0;
920 	}
921 	/*
922 	 * For all other LU groups aside from 'default_lu_gp', walk all of
923 	 * the associated storage objects looking for a matching target port
924 	 * group ID from the local target port group.
925 	 */
926 	spin_lock(&lu_gp->lu_gp_lock);
927 	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
928 				lu_gp_mem_list) {
929 
930 		dev = lu_gp_mem->lu_gp_mem_dev;
931 		atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
932 		smp_mb__after_atomic_inc();
933 		spin_unlock(&lu_gp->lu_gp_lock);
934 
935 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
936 		list_for_each_entry(tg_pt_gp,
937 				&dev->t10_alua.tg_pt_gps_list,
938 				tg_pt_gp_list) {
939 
940 			if (!tg_pt_gp->tg_pt_gp_valid_id)
941 				continue;
942 			/*
943 			 * If the target behavior port asymmetric access state
944 			 * is changed for any target port group accessible via
945 			 * a logical unit within a LU group, the target port
946 			 * behavior group asymmetric access states for the same
947 			 * target port group accessible via other logical units
948 			 * in that LU group will also change.
949 			 */
950 			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
951 				continue;
952 
953 			if (l_tg_pt_gp == tg_pt_gp) {
954 				port = l_port;
955 				nacl = l_nacl;
956 			} else {
957 				port = NULL;
958 				nacl = NULL;
959 			}
960 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
961 			smp_mb__after_atomic_inc();
962 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
963 			/*
964 			 * core_alua_do_transition_tg_pt() will always return
965 			 * success.
966 			 */
967 			core_alua_do_transition_tg_pt(tg_pt_gp, port,
968 					nacl, md_buf, new_state, explicit);
969 
970 			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
971 			atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
972 			smp_mb__after_atomic_dec();
973 		}
974 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
975 
976 		spin_lock(&lu_gp->lu_gp_lock);
977 		atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
978 		smp_mb__after_atomic_dec();
979 	}
980 	spin_unlock(&lu_gp->lu_gp_lock);
981 
982 	pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
983 		" Group IDs: %hu %s transition to primary state: %s\n",
984 		config_item_name(&lu_gp->lu_gp_group.cg_item),
985 		l_tg_pt_gp->tg_pt_gp_id, (explicit) ? "explicit" : "implicit",
986 		core_alua_dump_state(new_state));
987 
988 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
989 	smp_mb__after_atomic_dec();
990 	kfree(md_buf);
991 	return 0;
992 }
993 
994 /*
995  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
996  */
997 static int core_alua_update_tpg_secondary_metadata(
998 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
999 	struct se_port *port,
1000 	unsigned char *md_buf,
1001 	u32 md_buf_len)
1002 {
1003 	struct se_portal_group *se_tpg = port->sep_tpg;
1004 	char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1005 	int len;
1006 
1007 	memset(path, 0, ALUA_METADATA_PATH_LEN);
1008 	memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1009 
1010 	len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1011 			se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1012 
1013 	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1014 		snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1015 				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1016 
1017 	len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1018 			"alua_tg_pt_status=0x%02x\n",
1019 			atomic_read(&port->sep_tg_pt_secondary_offline),
1020 			port->sep_tg_pt_secondary_stat);
1021 
1022 	snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1023 			se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1024 			port->sep_lun->unpacked_lun);
1025 
1026 	return core_alua_write_tpg_metadata(path, md_buf, len);
1027 }
1028 
1029 static int core_alua_set_tg_pt_secondary_state(
1030 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1031 	struct se_port *port,
1032 	int explicit,
1033 	int offline)
1034 {
1035 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1036 	unsigned char *md_buf;
1037 	u32 md_buf_len;
1038 	int trans_delay_msecs;
1039 
1040 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1041 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1042 	if (!tg_pt_gp) {
1043 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1044 		pr_err("Unable to complete secondary state"
1045 				" transition\n");
1046 		return -EINVAL;
1047 	}
1048 	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1049 	/*
1050 	 * Set the secondary ALUA target port access state to OFFLINE
1051 	 * or release the previously secondary state for struct se_port
1052 	 */
1053 	if (offline)
1054 		atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1055 	else
1056 		atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1057 
1058 	md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1059 	port->sep_tg_pt_secondary_stat = (explicit) ?
1060 			ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1061 			ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1062 
1063 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1064 		" to secondary access state: %s\n", (explicit) ? "explicit" :
1065 		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1066 		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1067 
1068 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1069 	/*
1070 	 * Do the optional transition delay after we set the secondary
1071 	 * ALUA access state.
1072 	 */
1073 	if (trans_delay_msecs != 0)
1074 		msleep_interruptible(trans_delay_msecs);
1075 	/*
1076 	 * See if we need to update the ALUA fabric port metadata for
1077 	 * secondary state and status
1078 	 */
1079 	if (port->sep_tg_pt_secondary_write_md) {
1080 		md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1081 		if (!md_buf) {
1082 			pr_err("Unable to allocate md_buf for"
1083 				" secondary ALUA access metadata\n");
1084 			return -ENOMEM;
1085 		}
1086 		mutex_lock(&port->sep_tg_pt_md_mutex);
1087 		core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1088 				md_buf, md_buf_len);
1089 		mutex_unlock(&port->sep_tg_pt_md_mutex);
1090 
1091 		kfree(md_buf);
1092 	}
1093 
1094 	return 0;
1095 }
1096 
1097 struct t10_alua_lu_gp *
1098 core_alua_allocate_lu_gp(const char *name, int def_group)
1099 {
1100 	struct t10_alua_lu_gp *lu_gp;
1101 
1102 	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1103 	if (!lu_gp) {
1104 		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1105 		return ERR_PTR(-ENOMEM);
1106 	}
1107 	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1108 	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1109 	spin_lock_init(&lu_gp->lu_gp_lock);
1110 	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1111 
1112 	if (def_group) {
1113 		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1114 		lu_gp->lu_gp_valid_id = 1;
1115 		alua_lu_gps_count++;
1116 	}
1117 
1118 	return lu_gp;
1119 }
1120 
1121 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1122 {
1123 	struct t10_alua_lu_gp *lu_gp_tmp;
1124 	u16 lu_gp_id_tmp;
1125 	/*
1126 	 * The lu_gp->lu_gp_id may only be set once..
1127 	 */
1128 	if (lu_gp->lu_gp_valid_id) {
1129 		pr_warn("ALUA LU Group already has a valid ID,"
1130 			" ignoring request\n");
1131 		return -EINVAL;
1132 	}
1133 
1134 	spin_lock(&lu_gps_lock);
1135 	if (alua_lu_gps_count == 0x0000ffff) {
1136 		pr_err("Maximum ALUA alua_lu_gps_count:"
1137 				" 0x0000ffff reached\n");
1138 		spin_unlock(&lu_gps_lock);
1139 		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1140 		return -ENOSPC;
1141 	}
1142 again:
1143 	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1144 				alua_lu_gps_counter++;
1145 
1146 	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1147 		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1148 			if (!lu_gp_id)
1149 				goto again;
1150 
1151 			pr_warn("ALUA Logical Unit Group ID: %hu"
1152 				" already exists, ignoring request\n",
1153 				lu_gp_id);
1154 			spin_unlock(&lu_gps_lock);
1155 			return -EINVAL;
1156 		}
1157 	}
1158 
1159 	lu_gp->lu_gp_id = lu_gp_id_tmp;
1160 	lu_gp->lu_gp_valid_id = 1;
1161 	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1162 	alua_lu_gps_count++;
1163 	spin_unlock(&lu_gps_lock);
1164 
1165 	return 0;
1166 }
1167 
1168 static struct t10_alua_lu_gp_member *
1169 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1170 {
1171 	struct t10_alua_lu_gp_member *lu_gp_mem;
1172 
1173 	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1174 	if (!lu_gp_mem) {
1175 		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1176 		return ERR_PTR(-ENOMEM);
1177 	}
1178 	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1179 	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1180 	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1181 
1182 	lu_gp_mem->lu_gp_mem_dev = dev;
1183 	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1184 
1185 	return lu_gp_mem;
1186 }
1187 
1188 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1189 {
1190 	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1191 	/*
1192 	 * Once we have reached this point, config_item_put() has
1193 	 * already been called from target_core_alua_drop_lu_gp().
1194 	 *
1195 	 * Here, we remove the *lu_gp from the global list so that
1196 	 * no associations can be made while we are releasing
1197 	 * struct t10_alua_lu_gp.
1198 	 */
1199 	spin_lock(&lu_gps_lock);
1200 	list_del(&lu_gp->lu_gp_node);
1201 	alua_lu_gps_count--;
1202 	spin_unlock(&lu_gps_lock);
1203 	/*
1204 	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1205 	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1206 	 * released with core_alua_put_lu_gp_from_name()
1207 	 */
1208 	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1209 		cpu_relax();
1210 	/*
1211 	 * Release reference to struct t10_alua_lu_gp * from all associated
1212 	 * struct se_device.
1213 	 */
1214 	spin_lock(&lu_gp->lu_gp_lock);
1215 	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1216 				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1217 		if (lu_gp_mem->lu_gp_assoc) {
1218 			list_del(&lu_gp_mem->lu_gp_mem_list);
1219 			lu_gp->lu_gp_members--;
1220 			lu_gp_mem->lu_gp_assoc = 0;
1221 		}
1222 		spin_unlock(&lu_gp->lu_gp_lock);
1223 		/*
1224 		 *
1225 		 * lu_gp_mem is associated with a single
1226 		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1227 		 * struct se_device is released via core_alua_free_lu_gp_mem().
1228 		 *
1229 		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1230 		 * we want to re-associate a given lu_gp_mem with default_lu_gp.
1231 		 */
1232 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1233 		if (lu_gp != default_lu_gp)
1234 			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1235 					default_lu_gp);
1236 		else
1237 			lu_gp_mem->lu_gp = NULL;
1238 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1239 
1240 		spin_lock(&lu_gp->lu_gp_lock);
1241 	}
1242 	spin_unlock(&lu_gp->lu_gp_lock);
1243 
1244 	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1245 }
1246 
1247 void core_alua_free_lu_gp_mem(struct se_device *dev)
1248 {
1249 	struct t10_alua_lu_gp *lu_gp;
1250 	struct t10_alua_lu_gp_member *lu_gp_mem;
1251 
1252 	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1253 	if (!lu_gp_mem)
1254 		return;
1255 
1256 	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1257 		cpu_relax();
1258 
1259 	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1260 	lu_gp = lu_gp_mem->lu_gp;
1261 	if (lu_gp) {
1262 		spin_lock(&lu_gp->lu_gp_lock);
1263 		if (lu_gp_mem->lu_gp_assoc) {
1264 			list_del(&lu_gp_mem->lu_gp_mem_list);
1265 			lu_gp->lu_gp_members--;
1266 			lu_gp_mem->lu_gp_assoc = 0;
1267 		}
1268 		spin_unlock(&lu_gp->lu_gp_lock);
1269 		lu_gp_mem->lu_gp = NULL;
1270 	}
1271 	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1272 
1273 	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1274 }
1275 
1276 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1277 {
1278 	struct t10_alua_lu_gp *lu_gp;
1279 	struct config_item *ci;
1280 
1281 	spin_lock(&lu_gps_lock);
1282 	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1283 		if (!lu_gp->lu_gp_valid_id)
1284 			continue;
1285 		ci = &lu_gp->lu_gp_group.cg_item;
1286 		if (!strcmp(config_item_name(ci), name)) {
1287 			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1288 			spin_unlock(&lu_gps_lock);
1289 			return lu_gp;
1290 		}
1291 	}
1292 	spin_unlock(&lu_gps_lock);
1293 
1294 	return NULL;
1295 }
1296 
1297 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1298 {
1299 	spin_lock(&lu_gps_lock);
1300 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1301 	spin_unlock(&lu_gps_lock);
1302 }
1303 
1304 /*
1305  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1306  */
1307 void __core_alua_attach_lu_gp_mem(
1308 	struct t10_alua_lu_gp_member *lu_gp_mem,
1309 	struct t10_alua_lu_gp *lu_gp)
1310 {
1311 	spin_lock(&lu_gp->lu_gp_lock);
1312 	lu_gp_mem->lu_gp = lu_gp;
1313 	lu_gp_mem->lu_gp_assoc = 1;
1314 	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1315 	lu_gp->lu_gp_members++;
1316 	spin_unlock(&lu_gp->lu_gp_lock);
1317 }
1318 
1319 /*
1320  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1321  */
1322 void __core_alua_drop_lu_gp_mem(
1323 	struct t10_alua_lu_gp_member *lu_gp_mem,
1324 	struct t10_alua_lu_gp *lu_gp)
1325 {
1326 	spin_lock(&lu_gp->lu_gp_lock);
1327 	list_del(&lu_gp_mem->lu_gp_mem_list);
1328 	lu_gp_mem->lu_gp = NULL;
1329 	lu_gp_mem->lu_gp_assoc = 0;
1330 	lu_gp->lu_gp_members--;
1331 	spin_unlock(&lu_gp->lu_gp_lock);
1332 }
1333 
1334 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1335 		const char *name, int def_group)
1336 {
1337 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1338 
1339 	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1340 	if (!tg_pt_gp) {
1341 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1342 		return NULL;
1343 	}
1344 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1345 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1346 	mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1347 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1348 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1349 	tg_pt_gp->tg_pt_gp_dev = dev;
1350 	tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1351 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1352 		ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED);
1353 	/*
1354 	 * Enable both explicit and implicit ALUA support by default
1355 	 */
1356 	tg_pt_gp->tg_pt_gp_alua_access_type =
1357 			TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1358 	/*
1359 	 * Set the default Active/NonOptimized Delay in milliseconds
1360 	 */
1361 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1362 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1363 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1364 
1365 	/*
1366 	 * Enable all supported states
1367 	 */
1368 	tg_pt_gp->tg_pt_gp_alua_supported_states =
1369 	    ALUA_T_SUP | ALUA_O_SUP |
1370 	    ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1371 
1372 	if (def_group) {
1373 		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1374 		tg_pt_gp->tg_pt_gp_id =
1375 				dev->t10_alua.alua_tg_pt_gps_counter++;
1376 		tg_pt_gp->tg_pt_gp_valid_id = 1;
1377 		dev->t10_alua.alua_tg_pt_gps_count++;
1378 		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1379 			      &dev->t10_alua.tg_pt_gps_list);
1380 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1381 	}
1382 
1383 	return tg_pt_gp;
1384 }
1385 
1386 int core_alua_set_tg_pt_gp_id(
1387 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1388 	u16 tg_pt_gp_id)
1389 {
1390 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1391 	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1392 	u16 tg_pt_gp_id_tmp;
1393 
1394 	/*
1395 	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1396 	 */
1397 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1398 		pr_warn("ALUA TG PT Group already has a valid ID,"
1399 			" ignoring request\n");
1400 		return -EINVAL;
1401 	}
1402 
1403 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1404 	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1405 		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1406 			" 0x0000ffff reached\n");
1407 		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1408 		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1409 		return -ENOSPC;
1410 	}
1411 again:
1412 	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1413 			dev->t10_alua.alua_tg_pt_gps_counter++;
1414 
1415 	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1416 			tg_pt_gp_list) {
1417 		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1418 			if (!tg_pt_gp_id)
1419 				goto again;
1420 
1421 			pr_err("ALUA Target Port Group ID: %hu already"
1422 				" exists, ignoring request\n", tg_pt_gp_id);
1423 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1424 			return -EINVAL;
1425 		}
1426 	}
1427 
1428 	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1429 	tg_pt_gp->tg_pt_gp_valid_id = 1;
1430 	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1431 			&dev->t10_alua.tg_pt_gps_list);
1432 	dev->t10_alua.alua_tg_pt_gps_count++;
1433 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1434 
1435 	return 0;
1436 }
1437 
1438 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1439 	struct se_port *port)
1440 {
1441 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1442 
1443 	tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1444 				GFP_KERNEL);
1445 	if (!tg_pt_gp_mem) {
1446 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1447 		return ERR_PTR(-ENOMEM);
1448 	}
1449 	INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1450 	spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1451 	atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1452 
1453 	tg_pt_gp_mem->tg_pt = port;
1454 	port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1455 
1456 	return tg_pt_gp_mem;
1457 }
1458 
1459 void core_alua_free_tg_pt_gp(
1460 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1461 {
1462 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1463 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1464 
1465 	/*
1466 	 * Once we have reached this point, config_item_put() has already
1467 	 * been called from target_core_alua_drop_tg_pt_gp().
1468 	 *
1469 	 * Here we remove *tg_pt_gp from the global list so that
1470 	 * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1471 	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1472 	 */
1473 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1474 	list_del(&tg_pt_gp->tg_pt_gp_list);
1475 	dev->t10_alua.alua_tg_pt_gps_counter--;
1476 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1477 
1478 	/*
1479 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1480 	 * core_alua_get_tg_pt_gp_by_name() in
1481 	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1482 	 * to be released with core_alua_put_tg_pt_gp_from_name().
1483 	 */
1484 	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1485 		cpu_relax();
1486 
1487 	/*
1488 	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1489 	 * struct se_port.
1490 	 */
1491 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1492 	list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1493 			&tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1494 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1495 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1496 			tg_pt_gp->tg_pt_gp_members--;
1497 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1498 		}
1499 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1500 		/*
1501 		 * tg_pt_gp_mem is associated with a single
1502 		 * se_port->sep_alua_tg_pt_gp_mem, and is released via
1503 		 * core_alua_free_tg_pt_gp_mem().
1504 		 *
1505 		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1506 		 * assume we want to re-associate a given tg_pt_gp_mem with
1507 		 * default_tg_pt_gp.
1508 		 */
1509 		spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1510 		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1511 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1512 					dev->t10_alua.default_tg_pt_gp);
1513 		} else
1514 			tg_pt_gp_mem->tg_pt_gp = NULL;
1515 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1516 
1517 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1518 	}
1519 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1520 
1521 	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1522 }
1523 
1524 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1525 {
1526 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1527 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1528 
1529 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1530 	if (!tg_pt_gp_mem)
1531 		return;
1532 
1533 	while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1534 		cpu_relax();
1535 
1536 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1537 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1538 	if (tg_pt_gp) {
1539 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1540 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1541 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1542 			tg_pt_gp->tg_pt_gp_members--;
1543 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1544 		}
1545 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1546 		tg_pt_gp_mem->tg_pt_gp = NULL;
1547 	}
1548 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1549 
1550 	kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1551 }
1552 
1553 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1554 		struct se_device *dev, const char *name)
1555 {
1556 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1557 	struct config_item *ci;
1558 
1559 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1560 	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1561 			tg_pt_gp_list) {
1562 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1563 			continue;
1564 		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1565 		if (!strcmp(config_item_name(ci), name)) {
1566 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1567 			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1568 			return tg_pt_gp;
1569 		}
1570 	}
1571 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1572 
1573 	return NULL;
1574 }
1575 
1576 static void core_alua_put_tg_pt_gp_from_name(
1577 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1578 {
1579 	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1580 
1581 	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1582 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1583 	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1584 }
1585 
1586 /*
1587  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1588  */
1589 void __core_alua_attach_tg_pt_gp_mem(
1590 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1591 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1592 {
1593 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1594 	tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1595 	tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1596 	list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1597 			&tg_pt_gp->tg_pt_gp_mem_list);
1598 	tg_pt_gp->tg_pt_gp_members++;
1599 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1600 }
1601 
1602 /*
1603  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1604  */
1605 static void __core_alua_drop_tg_pt_gp_mem(
1606 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1607 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1608 {
1609 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1610 	list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1611 	tg_pt_gp_mem->tg_pt_gp = NULL;
1612 	tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1613 	tg_pt_gp->tg_pt_gp_members--;
1614 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1615 }
1616 
1617 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1618 {
1619 	struct config_item *tg_pt_ci;
1620 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1621 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1622 	ssize_t len = 0;
1623 
1624 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1625 	if (!tg_pt_gp_mem)
1626 		return len;
1627 
1628 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1629 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1630 	if (tg_pt_gp) {
1631 		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1632 		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1633 			" %hu\nTG Port Primary Access State: %s\nTG Port "
1634 			"Primary Access Status: %s\nTG Port Secondary Access"
1635 			" State: %s\nTG Port Secondary Access Status: %s\n",
1636 			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1637 			core_alua_dump_state(atomic_read(
1638 					&tg_pt_gp->tg_pt_gp_alua_access_state)),
1639 			core_alua_dump_status(
1640 				tg_pt_gp->tg_pt_gp_alua_access_status),
1641 			(atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1642 			"Offline" : "None",
1643 			core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1644 	}
1645 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1646 
1647 	return len;
1648 }
1649 
1650 ssize_t core_alua_store_tg_pt_gp_info(
1651 	struct se_port *port,
1652 	const char *page,
1653 	size_t count)
1654 {
1655 	struct se_portal_group *tpg;
1656 	struct se_lun *lun;
1657 	struct se_device *dev = port->sep_lun->lun_se_dev;
1658 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1659 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1660 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1661 	int move = 0;
1662 
1663 	tpg = port->sep_tpg;
1664 	lun = port->sep_lun;
1665 
1666 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1667 	if (!tg_pt_gp_mem)
1668 		return 0;
1669 
1670 	if (count > TG_PT_GROUP_NAME_BUF) {
1671 		pr_err("ALUA Target Port Group alias too large!\n");
1672 		return -EINVAL;
1673 	}
1674 	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1675 	memcpy(buf, page, count);
1676 	/*
1677 	 * Any ALUA target port group alias besides "NULL" means we will be
1678 	 * making a new group association.
1679 	 */
1680 	if (strcmp(strstrip(buf), "NULL")) {
1681 		/*
1682 		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1683 		 * struct t10_alua_tg_pt_gp.  This reference is released with
1684 		 * core_alua_put_tg_pt_gp_from_name() below.
1685 		 */
1686 		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1687 					strstrip(buf));
1688 		if (!tg_pt_gp_new)
1689 			return -ENODEV;
1690 	}
1691 
1692 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1693 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1694 	if (tg_pt_gp) {
1695 		/*
1696 		 * Clearing an existing tg_pt_gp association, and replacing
1697 		 * with the default_tg_pt_gp.
1698 		 */
1699 		if (!tg_pt_gp_new) {
1700 			pr_debug("Target_Core_ConfigFS: Moving"
1701 				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
1702 				" alua/%s, ID: %hu back to"
1703 				" default_tg_pt_gp\n",
1704 				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1705 				tpg->se_tpg_tfo->tpg_get_tag(tpg),
1706 				config_item_name(&lun->lun_group.cg_item),
1707 				config_item_name(
1708 					&tg_pt_gp->tg_pt_gp_group.cg_item),
1709 				tg_pt_gp->tg_pt_gp_id);
1710 
1711 			__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1712 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1713 					dev->t10_alua.default_tg_pt_gp);
1714 			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1715 
1716 			return count;
1717 		}
1718 		/*
1719 		 * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1720 		 */
1721 		__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1722 		move = 1;
1723 	}
1724 	/*
1725 	 * Associate tg_pt_gp_mem with tg_pt_gp_new.
1726 	 */
1727 	__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1728 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1729 	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1730 		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
1731 		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1732 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
1733 		config_item_name(&lun->lun_group.cg_item),
1734 		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1735 		tg_pt_gp_new->tg_pt_gp_id);
1736 
1737 	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1738 	return count;
1739 }
1740 
1741 ssize_t core_alua_show_access_type(
1742 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1743 	char *page)
1744 {
1745 	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
1746 	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
1747 		return sprintf(page, "Implicit and Explicit\n");
1748 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
1749 		return sprintf(page, "Implicit\n");
1750 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
1751 		return sprintf(page, "Explicit\n");
1752 	else
1753 		return sprintf(page, "None\n");
1754 }
1755 
1756 ssize_t core_alua_store_access_type(
1757 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1758 	const char *page,
1759 	size_t count)
1760 {
1761 	unsigned long tmp;
1762 	int ret;
1763 
1764 	ret = kstrtoul(page, 0, &tmp);
1765 	if (ret < 0) {
1766 		pr_err("Unable to extract alua_access_type\n");
1767 		return ret;
1768 	}
1769 	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1770 		pr_err("Illegal value for alua_access_type:"
1771 				" %lu\n", tmp);
1772 		return -EINVAL;
1773 	}
1774 	if (tmp == 3)
1775 		tg_pt_gp->tg_pt_gp_alua_access_type =
1776 			TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
1777 	else if (tmp == 2)
1778 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
1779 	else if (tmp == 1)
1780 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
1781 	else
1782 		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1783 
1784 	return count;
1785 }
1786 
1787 ssize_t core_alua_show_nonop_delay_msecs(
1788 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1789 	char *page)
1790 {
1791 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1792 }
1793 
1794 ssize_t core_alua_store_nonop_delay_msecs(
1795 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1796 	const char *page,
1797 	size_t count)
1798 {
1799 	unsigned long tmp;
1800 	int ret;
1801 
1802 	ret = kstrtoul(page, 0, &tmp);
1803 	if (ret < 0) {
1804 		pr_err("Unable to extract nonop_delay_msecs\n");
1805 		return ret;
1806 	}
1807 	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1808 		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1809 			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1810 			ALUA_MAX_NONOP_DELAY_MSECS);
1811 		return -EINVAL;
1812 	}
1813 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1814 
1815 	return count;
1816 }
1817 
1818 ssize_t core_alua_show_trans_delay_msecs(
1819 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1820 	char *page)
1821 {
1822 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1823 }
1824 
1825 ssize_t core_alua_store_trans_delay_msecs(
1826 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1827 	const char *page,
1828 	size_t count)
1829 {
1830 	unsigned long tmp;
1831 	int ret;
1832 
1833 	ret = kstrtoul(page, 0, &tmp);
1834 	if (ret < 0) {
1835 		pr_err("Unable to extract trans_delay_msecs\n");
1836 		return ret;
1837 	}
1838 	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1839 		pr_err("Passed trans_delay_msecs: %lu, exceeds"
1840 			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1841 			ALUA_MAX_TRANS_DELAY_MSECS);
1842 		return -EINVAL;
1843 	}
1844 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1845 
1846 	return count;
1847 }
1848 
1849 ssize_t core_alua_show_implicit_trans_secs(
1850 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1851 	char *page)
1852 {
1853 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
1854 }
1855 
1856 ssize_t core_alua_store_implicit_trans_secs(
1857 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1858 	const char *page,
1859 	size_t count)
1860 {
1861 	unsigned long tmp;
1862 	int ret;
1863 
1864 	ret = kstrtoul(page, 0, &tmp);
1865 	if (ret < 0) {
1866 		pr_err("Unable to extract implicit_trans_secs\n");
1867 		return ret;
1868 	}
1869 	if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
1870 		pr_err("Passed implicit_trans_secs: %lu, exceeds"
1871 			" ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
1872 			ALUA_MAX_IMPLICIT_TRANS_SECS);
1873 		return  -EINVAL;
1874 	}
1875 	tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
1876 
1877 	return count;
1878 }
1879 
1880 ssize_t core_alua_show_preferred_bit(
1881 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1882 	char *page)
1883 {
1884 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1885 }
1886 
1887 ssize_t core_alua_store_preferred_bit(
1888 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1889 	const char *page,
1890 	size_t count)
1891 {
1892 	unsigned long tmp;
1893 	int ret;
1894 
1895 	ret = kstrtoul(page, 0, &tmp);
1896 	if (ret < 0) {
1897 		pr_err("Unable to extract preferred ALUA value\n");
1898 		return ret;
1899 	}
1900 	if ((tmp != 0) && (tmp != 1)) {
1901 		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1902 		return -EINVAL;
1903 	}
1904 	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1905 
1906 	return count;
1907 }
1908 
1909 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1910 {
1911 	if (!lun->lun_sep)
1912 		return -ENODEV;
1913 
1914 	return sprintf(page, "%d\n",
1915 		atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1916 }
1917 
1918 ssize_t core_alua_store_offline_bit(
1919 	struct se_lun *lun,
1920 	const char *page,
1921 	size_t count)
1922 {
1923 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1924 	unsigned long tmp;
1925 	int ret;
1926 
1927 	if (!lun->lun_sep)
1928 		return -ENODEV;
1929 
1930 	ret = kstrtoul(page, 0, &tmp);
1931 	if (ret < 0) {
1932 		pr_err("Unable to extract alua_tg_pt_offline value\n");
1933 		return ret;
1934 	}
1935 	if ((tmp != 0) && (tmp != 1)) {
1936 		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1937 				tmp);
1938 		return -EINVAL;
1939 	}
1940 	tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1941 	if (!tg_pt_gp_mem) {
1942 		pr_err("Unable to locate *tg_pt_gp_mem\n");
1943 		return -EINVAL;
1944 	}
1945 
1946 	ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1947 			lun->lun_sep, 0, (int)tmp);
1948 	if (ret < 0)
1949 		return -EINVAL;
1950 
1951 	return count;
1952 }
1953 
1954 ssize_t core_alua_show_secondary_status(
1955 	struct se_lun *lun,
1956 	char *page)
1957 {
1958 	return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1959 }
1960 
1961 ssize_t core_alua_store_secondary_status(
1962 	struct se_lun *lun,
1963 	const char *page,
1964 	size_t count)
1965 {
1966 	unsigned long tmp;
1967 	int ret;
1968 
1969 	ret = kstrtoul(page, 0, &tmp);
1970 	if (ret < 0) {
1971 		pr_err("Unable to extract alua_tg_pt_status\n");
1972 		return ret;
1973 	}
1974 	if ((tmp != ALUA_STATUS_NONE) &&
1975 	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
1976 	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
1977 		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
1978 				tmp);
1979 		return -EINVAL;
1980 	}
1981 	lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
1982 
1983 	return count;
1984 }
1985 
1986 ssize_t core_alua_show_secondary_write_metadata(
1987 	struct se_lun *lun,
1988 	char *page)
1989 {
1990 	return sprintf(page, "%d\n",
1991 			lun->lun_sep->sep_tg_pt_secondary_write_md);
1992 }
1993 
1994 ssize_t core_alua_store_secondary_write_metadata(
1995 	struct se_lun *lun,
1996 	const char *page,
1997 	size_t count)
1998 {
1999 	unsigned long tmp;
2000 	int ret;
2001 
2002 	ret = kstrtoul(page, 0, &tmp);
2003 	if (ret < 0) {
2004 		pr_err("Unable to extract alua_tg_pt_write_md\n");
2005 		return ret;
2006 	}
2007 	if ((tmp != 0) && (tmp != 1)) {
2008 		pr_err("Illegal value for alua_tg_pt_write_md:"
2009 				" %lu\n", tmp);
2010 		return -EINVAL;
2011 	}
2012 	lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
2013 
2014 	return count;
2015 }
2016 
2017 int core_setup_alua(struct se_device *dev)
2018 {
2019 	if (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV &&
2020 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2021 		struct t10_alua_lu_gp_member *lu_gp_mem;
2022 
2023 		/*
2024 		 * Associate this struct se_device with the default ALUA
2025 		 * LUN Group.
2026 		 */
2027 		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2028 		if (IS_ERR(lu_gp_mem))
2029 			return PTR_ERR(lu_gp_mem);
2030 
2031 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2032 		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2033 				default_lu_gp);
2034 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2035 
2036 		pr_debug("%s: Adding to default ALUA LU Group:"
2037 			" core/alua/lu_gps/default_lu_gp\n",
2038 			dev->transport->name);
2039 	}
2040 
2041 	return 0;
2042 }
2043