1 /*******************************************************************************
2  * Filename:  target_core_alua.c
3  *
4  * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
5  *
6  * Copyright (c) 2009-2010 Rising Tide Systems
7  * Copyright (c) 2009-2010 Linux-iSCSI.org
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24  *
25  ******************************************************************************/
26 
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/configfs.h>
30 #include <linux/export.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 int 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 int target_emulate_report_target_port_groups(struct se_cmd *cmd)
63 {
64 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
65 	struct se_port *port;
66 	struct t10_alua_tg_pt_gp *tg_pt_gp;
67 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
68 	unsigned char *buf;
69 	u32 rd_len = 0, off;
70 	int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
71 	/*
72 	 * Skip over RESERVED area to first Target port group descriptor
73 	 * depending on the PARAMETER DATA FORMAT type..
74 	 */
75 	if (ext_hdr != 0)
76 		off = 8;
77 	else
78 		off = 4;
79 
80 	if (cmd->data_length < off) {
81 		pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
82 			" small for %s header\n", cmd->data_length,
83 			(ext_hdr) ? "extended" : "normal");
84 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
85 		return -EINVAL;
86 	}
87 	buf = transport_kmap_data_sg(cmd);
88 
89 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
90 	list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
91 			tg_pt_gp_list) {
92 		/*
93 		 * Check if the Target port group and Target port descriptor list
94 		 * based on tg_pt_gp_members count will fit into the response payload.
95 		 * Otherwise, bump rd_len to let the initiator know we have exceeded
96 		 * the allocation length and the response is truncated.
97 		 */
98 		if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
99 		     cmd->data_length) {
100 			rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
101 			continue;
102 		}
103 		/*
104 		 * PREF: Preferred target port bit, determine if this
105 		 * bit should be set for port group.
106 		 */
107 		if (tg_pt_gp->tg_pt_gp_pref)
108 			buf[off] = 0x80;
109 		/*
110 		 * Set the ASYMMETRIC ACCESS State
111 		 */
112 		buf[off++] |= (atomic_read(
113 			&tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
114 		/*
115 		 * Set supported ASYMMETRIC ACCESS State bits
116 		 */
117 		buf[off] = 0x80; /* T_SUP */
118 		buf[off] |= 0x40; /* O_SUP */
119 		buf[off] |= 0x8; /* U_SUP */
120 		buf[off] |= 0x4; /* S_SUP */
121 		buf[off] |= 0x2; /* AN_SUP */
122 		buf[off++] |= 0x1; /* AO_SUP */
123 		/*
124 		 * TARGET PORT GROUP
125 		 */
126 		buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
127 		buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
128 
129 		off++; /* Skip over Reserved */
130 		/*
131 		 * STATUS CODE
132 		 */
133 		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
134 		/*
135 		 * Vendor Specific field
136 		 */
137 		buf[off++] = 0x00;
138 		/*
139 		 * TARGET PORT COUNT
140 		 */
141 		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
142 		rd_len += 8;
143 
144 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
145 		list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
146 				tg_pt_gp_mem_list) {
147 			port = tg_pt_gp_mem->tg_pt;
148 			/*
149 			 * Start Target Port descriptor format
150 			 *
151 			 * See spc4r17 section 6.2.7 Table 247
152 			 */
153 			off += 2; /* Skip over Obsolete */
154 			/*
155 			 * Set RELATIVE TARGET PORT IDENTIFIER
156 			 */
157 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
158 			buf[off++] = (port->sep_rtpi & 0xff);
159 			rd_len += 4;
160 		}
161 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
162 	}
163 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
164 	/*
165 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
166 	 */
167 	put_unaligned_be32(rd_len, &buf[0]);
168 
169 	/*
170 	 * Fill in the Extended header parameter data format if requested
171 	 */
172 	if (ext_hdr != 0) {
173 		buf[4] = 0x10;
174 		/*
175 		 * Set the implict transition time (in seconds) for the application
176 		 * client to use as a base for it's transition timeout value.
177 		 *
178 		 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
179 		 * this CDB was received upon to determine this value individually
180 		 * for ALUA target port group.
181 		 */
182 		port = cmd->se_lun->lun_sep;
183 		tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
184 		if (tg_pt_gp_mem) {
185 			spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
186 			tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
187 			if (tg_pt_gp)
188 				buf[5] = tg_pt_gp->tg_pt_gp_implict_trans_secs;
189 			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
190 		}
191 	}
192 	transport_kunmap_data_sg(cmd);
193 
194 	target_complete_cmd(cmd, GOOD);
195 	return 0;
196 }
197 
198 /*
199  * SET_TARGET_PORT_GROUPS for explict ALUA operation.
200  *
201  * See spc4r17 section 6.35
202  */
203 int target_emulate_set_target_port_groups(struct se_cmd *cmd)
204 {
205 	struct se_device *dev = cmd->se_dev;
206 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
207 	struct se_port *port, *l_port = cmd->se_lun->lun_sep;
208 	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
209 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
210 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
211 	unsigned char *buf;
212 	unsigned char *ptr;
213 	u32 len = 4; /* Skip over RESERVED area in header */
214 	int alua_access_state, primary = 0, rc;
215 	u16 tg_pt_id, rtpi;
216 
217 	if (!l_port) {
218 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
219 		return -EINVAL;
220 	}
221 	buf = transport_kmap_data_sg(cmd);
222 
223 	/*
224 	 * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
225 	 * for the local tg_pt_gp.
226 	 */
227 	l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
228 	if (!l_tg_pt_gp_mem) {
229 		pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
230 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
231 		rc = -EINVAL;
232 		goto out;
233 	}
234 	spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
235 	l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
236 	if (!l_tg_pt_gp) {
237 		spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
238 		pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
239 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
240 		rc = -EINVAL;
241 		goto out;
242 	}
243 	rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
244 	spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
245 
246 	if (!rc) {
247 		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
248 				" while TPGS_EXPLICT_ALUA is disabled\n");
249 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
250 		rc = -EINVAL;
251 		goto out;
252 	}
253 
254 	ptr = &buf[4]; /* Skip over RESERVED area in header */
255 
256 	while (len < cmd->data_length) {
257 		alua_access_state = (ptr[0] & 0x0f);
258 		/*
259 		 * Check the received ALUA access state, and determine if
260 		 * the state is a primary or secondary target port asymmetric
261 		 * access state.
262 		 */
263 		rc = core_alua_check_transition(alua_access_state, &primary);
264 		if (rc != 0) {
265 			/*
266 			 * If the SET TARGET PORT GROUPS attempts to establish
267 			 * an invalid combination of target port asymmetric
268 			 * access states or attempts to establish an
269 			 * unsupported target port asymmetric access state,
270 			 * then the command shall be terminated with CHECK
271 			 * CONDITION status, with the sense key set to ILLEGAL
272 			 * REQUEST, and the additional sense code set to INVALID
273 			 * FIELD IN PARAMETER LIST.
274 			 */
275 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
276 			rc = -EINVAL;
277 			goto out;
278 		}
279 		rc = -1;
280 		/*
281 		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
282 		 * specifies a primary target port asymmetric access state,
283 		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
284 		 * a primary target port group for which the primary target
285 		 * port asymmetric access state shall be changed. If the
286 		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
287 		 * port asymmetric access state, then the TARGET PORT GROUP OR
288 		 * TARGET PORT field specifies the relative target port
289 		 * identifier (see 3.1.120) of the target port for which the
290 		 * secondary target port asymmetric access state shall be
291 		 * changed.
292 		 */
293 		if (primary) {
294 			tg_pt_id = get_unaligned_be16(ptr + 2);
295 			/*
296 			 * Locate the matching target port group ID from
297 			 * the global tg_pt_gp list
298 			 */
299 			spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
300 			list_for_each_entry(tg_pt_gp,
301 					&su_dev->t10_alua.tg_pt_gps_list,
302 					tg_pt_gp_list) {
303 				if (!tg_pt_gp->tg_pt_gp_valid_id)
304 					continue;
305 
306 				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
307 					continue;
308 
309 				atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
310 				smp_mb__after_atomic_inc();
311 				spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
312 
313 				rc = core_alua_do_port_transition(tg_pt_gp,
314 						dev, l_port, nacl,
315 						alua_access_state, 1);
316 
317 				spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
318 				atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
319 				smp_mb__after_atomic_dec();
320 				break;
321 			}
322 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
323 			/*
324 			 * If not matching target port group ID can be located
325 			 * throw an exception with ASCQ: INVALID_PARAMETER_LIST
326 			 */
327 			if (rc != 0) {
328 				cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
329 				rc = -EINVAL;
330 				goto out;
331 			}
332 		} else {
333 			/*
334 			 * Extact the RELATIVE TARGET PORT IDENTIFIER to identify
335 			 * the Target Port in question for the the incoming
336 			 * SET_TARGET_PORT_GROUPS op.
337 			 */
338 			rtpi = get_unaligned_be16(ptr + 2);
339 			/*
340 			 * Locate the matching relative target port identifer
341 			 * for the struct se_device storage object.
342 			 */
343 			spin_lock(&dev->se_port_lock);
344 			list_for_each_entry(port, &dev->dev_sep_list,
345 							sep_list) {
346 				if (port->sep_rtpi != rtpi)
347 					continue;
348 
349 				tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
350 				spin_unlock(&dev->se_port_lock);
351 
352 				rc = core_alua_set_tg_pt_secondary_state(
353 						tg_pt_gp_mem, port, 1, 1);
354 
355 				spin_lock(&dev->se_port_lock);
356 				break;
357 			}
358 			spin_unlock(&dev->se_port_lock);
359 			/*
360 			 * If not matching relative target port identifier can
361 			 * be located, throw an exception with ASCQ:
362 			 * INVALID_PARAMETER_LIST
363 			 */
364 			if (rc != 0) {
365 				cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
366 				rc = -EINVAL;
367 				goto out;
368 			}
369 		}
370 
371 		ptr += 4;
372 		len += 4;
373 	}
374 
375 out:
376 	transport_kunmap_data_sg(cmd);
377 	if (!rc)
378 		target_complete_cmd(cmd, GOOD);
379 	return rc;
380 }
381 
382 static inline int core_alua_state_nonoptimized(
383 	struct se_cmd *cmd,
384 	unsigned char *cdb,
385 	int nonop_delay_msecs,
386 	u8 *alua_ascq)
387 {
388 	/*
389 	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
390 	 * later to determine if processing of this cmd needs to be
391 	 * temporarily delayed for the Active/NonOptimized primary access state.
392 	 */
393 	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
394 	cmd->alua_nonop_delay = nonop_delay_msecs;
395 	return 0;
396 }
397 
398 static inline int core_alua_state_standby(
399 	struct se_cmd *cmd,
400 	unsigned char *cdb,
401 	u8 *alua_ascq)
402 {
403 	/*
404 	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
405 	 * spc4r17 section 5.9.2.4.4
406 	 */
407 	switch (cdb[0]) {
408 	case INQUIRY:
409 	case LOG_SELECT:
410 	case LOG_SENSE:
411 	case MODE_SELECT:
412 	case MODE_SENSE:
413 	case REPORT_LUNS:
414 	case RECEIVE_DIAGNOSTIC:
415 	case SEND_DIAGNOSTIC:
416 	case MAINTENANCE_IN:
417 		switch (cdb[1] & 0x1f) {
418 		case MI_REPORT_TARGET_PGS:
419 			return 0;
420 		default:
421 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
422 			return 1;
423 		}
424 	case MAINTENANCE_OUT:
425 		switch (cdb[1]) {
426 		case MO_SET_TARGET_PGS:
427 			return 0;
428 		default:
429 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
430 			return 1;
431 		}
432 	case REQUEST_SENSE:
433 	case PERSISTENT_RESERVE_IN:
434 	case PERSISTENT_RESERVE_OUT:
435 	case READ_BUFFER:
436 	case WRITE_BUFFER:
437 		return 0;
438 	default:
439 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
440 		return 1;
441 	}
442 
443 	return 0;
444 }
445 
446 static inline int core_alua_state_unavailable(
447 	struct se_cmd *cmd,
448 	unsigned char *cdb,
449 	u8 *alua_ascq)
450 {
451 	/*
452 	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
453 	 * spc4r17 section 5.9.2.4.5
454 	 */
455 	switch (cdb[0]) {
456 	case INQUIRY:
457 	case REPORT_LUNS:
458 	case MAINTENANCE_IN:
459 		switch (cdb[1] & 0x1f) {
460 		case MI_REPORT_TARGET_PGS:
461 			return 0;
462 		default:
463 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
464 			return 1;
465 		}
466 	case MAINTENANCE_OUT:
467 		switch (cdb[1]) {
468 		case MO_SET_TARGET_PGS:
469 			return 0;
470 		default:
471 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
472 			return 1;
473 		}
474 	case REQUEST_SENSE:
475 	case READ_BUFFER:
476 	case WRITE_BUFFER:
477 		return 0;
478 	default:
479 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
480 		return 1;
481 	}
482 
483 	return 0;
484 }
485 
486 static inline int core_alua_state_transition(
487 	struct se_cmd *cmd,
488 	unsigned char *cdb,
489 	u8 *alua_ascq)
490 {
491 	/*
492 	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
493 	 * spc4r17 section 5.9.2.5
494 	 */
495 	switch (cdb[0]) {
496 	case INQUIRY:
497 	case REPORT_LUNS:
498 	case MAINTENANCE_IN:
499 		switch (cdb[1] & 0x1f) {
500 		case MI_REPORT_TARGET_PGS:
501 			return 0;
502 		default:
503 			*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
504 			return 1;
505 		}
506 	case REQUEST_SENSE:
507 	case READ_BUFFER:
508 	case WRITE_BUFFER:
509 		return 0;
510 	default:
511 		*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
512 		return 1;
513 	}
514 
515 	return 0;
516 }
517 
518 /*
519  * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
520  * in transport_cmd_sequencer().  This function is assigned to
521  * struct t10_alua *->state_check() in core_setup_alua()
522  */
523 static int core_alua_state_check_nop(
524 	struct se_cmd *cmd,
525 	unsigned char *cdb,
526 	u8 *alua_ascq)
527 {
528 	return 0;
529 }
530 
531 /*
532  * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
533  * This function is assigned to struct t10_alua *->state_check() in
534  * core_setup_alua()
535  *
536  * Also, this function can return three different return codes to
537  * signal transport_generic_cmd_sequencer()
538  *
539  * return 1: Is used to signal LUN not accecsable, and check condition/not ready
540  * return 0: Used to signal success
541  * reutrn -1: Used to signal failure, and invalid cdb field
542  */
543 static int core_alua_state_check(
544 	struct se_cmd *cmd,
545 	unsigned char *cdb,
546 	u8 *alua_ascq)
547 {
548 	struct se_lun *lun = cmd->se_lun;
549 	struct se_port *port = lun->lun_sep;
550 	struct t10_alua_tg_pt_gp *tg_pt_gp;
551 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
552 	int out_alua_state, nonop_delay_msecs;
553 
554 	if (!port)
555 		return 0;
556 	/*
557 	 * First, check for a struct se_port specific secondary ALUA target port
558 	 * access state: OFFLINE
559 	 */
560 	if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
561 		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
562 		pr_debug("ALUA: Got secondary offline status for local"
563 				" target port\n");
564 		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
565 		return 1;
566 	}
567 	 /*
568 	 * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
569 	 * ALUA target port group, to obtain current ALUA access state.
570 	 * Otherwise look for the underlying struct se_device association with
571 	 * a ALUA logical unit group.
572 	 */
573 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
574 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
575 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
576 	out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
577 	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
578 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
579 	/*
580 	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
581 	 * statement so the compiler knows explicitly to check this case first.
582 	 * For the Optimized ALUA access state case, we want to process the
583 	 * incoming fabric cmd ASAP..
584 	 */
585 	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
586 		return 0;
587 
588 	switch (out_alua_state) {
589 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
590 		return core_alua_state_nonoptimized(cmd, cdb,
591 					nonop_delay_msecs, alua_ascq);
592 	case ALUA_ACCESS_STATE_STANDBY:
593 		return core_alua_state_standby(cmd, cdb, alua_ascq);
594 	case ALUA_ACCESS_STATE_UNAVAILABLE:
595 		return core_alua_state_unavailable(cmd, cdb, alua_ascq);
596 	case ALUA_ACCESS_STATE_TRANSITION:
597 		return core_alua_state_transition(cmd, cdb, alua_ascq);
598 	/*
599 	 * OFFLINE is a secondary ALUA target port group access state, that is
600 	 * handled above with struct se_port->sep_tg_pt_secondary_offline=1
601 	 */
602 	case ALUA_ACCESS_STATE_OFFLINE:
603 	default:
604 		pr_err("Unknown ALUA access state: 0x%02x\n",
605 				out_alua_state);
606 		return -EINVAL;
607 	}
608 
609 	return 0;
610 }
611 
612 /*
613  * Check implict and explict ALUA state change request.
614  */
615 static int core_alua_check_transition(int state, int *primary)
616 {
617 	switch (state) {
618 	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
619 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
620 	case ALUA_ACCESS_STATE_STANDBY:
621 	case ALUA_ACCESS_STATE_UNAVAILABLE:
622 		/*
623 		 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
624 		 * defined as primary target port asymmetric access states.
625 		 */
626 		*primary = 1;
627 		break;
628 	case ALUA_ACCESS_STATE_OFFLINE:
629 		/*
630 		 * OFFLINE state is defined as a secondary target port
631 		 * asymmetric access state.
632 		 */
633 		*primary = 0;
634 		break;
635 	default:
636 		pr_err("Unknown ALUA access state: 0x%02x\n", state);
637 		return -EINVAL;
638 	}
639 
640 	return 0;
641 }
642 
643 static char *core_alua_dump_state(int state)
644 {
645 	switch (state) {
646 	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
647 		return "Active/Optimized";
648 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
649 		return "Active/NonOptimized";
650 	case ALUA_ACCESS_STATE_STANDBY:
651 		return "Standby";
652 	case ALUA_ACCESS_STATE_UNAVAILABLE:
653 		return "Unavailable";
654 	case ALUA_ACCESS_STATE_OFFLINE:
655 		return "Offline";
656 	default:
657 		return "Unknown";
658 	}
659 
660 	return NULL;
661 }
662 
663 char *core_alua_dump_status(int status)
664 {
665 	switch (status) {
666 	case ALUA_STATUS_NONE:
667 		return "None";
668 	case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
669 		return "Altered by Explict STPG";
670 	case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
671 		return "Altered by Implict ALUA";
672 	default:
673 		return "Unknown";
674 	}
675 
676 	return NULL;
677 }
678 
679 /*
680  * Used by fabric modules to determine when we need to delay processing
681  * for the Active/NonOptimized paths..
682  */
683 int core_alua_check_nonop_delay(
684 	struct se_cmd *cmd)
685 {
686 	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
687 		return 0;
688 	if (in_interrupt())
689 		return 0;
690 	/*
691 	 * The ALUA Active/NonOptimized access state delay can be disabled
692 	 * in via configfs with a value of zero
693 	 */
694 	if (!cmd->alua_nonop_delay)
695 		return 0;
696 	/*
697 	 * struct se_cmd->alua_nonop_delay gets set by a target port group
698 	 * defined interval in core_alua_state_nonoptimized()
699 	 */
700 	msleep_interruptible(cmd->alua_nonop_delay);
701 	return 0;
702 }
703 EXPORT_SYMBOL(core_alua_check_nonop_delay);
704 
705 /*
706  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
707  *
708  */
709 static int core_alua_write_tpg_metadata(
710 	const char *path,
711 	unsigned char *md_buf,
712 	u32 md_buf_len)
713 {
714 	mm_segment_t old_fs;
715 	struct file *file;
716 	struct iovec iov[1];
717 	int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
718 
719 	memset(iov, 0, sizeof(struct iovec));
720 
721 	file = filp_open(path, flags, 0600);
722 	if (IS_ERR(file) || !file || !file->f_dentry) {
723 		pr_err("filp_open(%s) for ALUA metadata failed\n",
724 			path);
725 		return -ENODEV;
726 	}
727 
728 	iov[0].iov_base = &md_buf[0];
729 	iov[0].iov_len = md_buf_len;
730 
731 	old_fs = get_fs();
732 	set_fs(get_ds());
733 	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
734 	set_fs(old_fs);
735 
736 	if (ret < 0) {
737 		pr_err("Error writing ALUA metadata file: %s\n", path);
738 		filp_close(file, NULL);
739 		return -EIO;
740 	}
741 	filp_close(file, NULL);
742 
743 	return 0;
744 }
745 
746 /*
747  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
748  */
749 static int core_alua_update_tpg_primary_metadata(
750 	struct t10_alua_tg_pt_gp *tg_pt_gp,
751 	int primary_state,
752 	unsigned char *md_buf)
753 {
754 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
755 	struct t10_wwn *wwn = &su_dev->t10_wwn;
756 	char path[ALUA_METADATA_PATH_LEN];
757 	int len;
758 
759 	memset(path, 0, ALUA_METADATA_PATH_LEN);
760 
761 	len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
762 			"tg_pt_gp_id=%hu\n"
763 			"alua_access_state=0x%02x\n"
764 			"alua_access_status=0x%02x\n",
765 			tg_pt_gp->tg_pt_gp_id, primary_state,
766 			tg_pt_gp->tg_pt_gp_alua_access_status);
767 
768 	snprintf(path, ALUA_METADATA_PATH_LEN,
769 		"/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
770 		config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
771 
772 	return core_alua_write_tpg_metadata(path, md_buf, len);
773 }
774 
775 static int core_alua_do_transition_tg_pt(
776 	struct t10_alua_tg_pt_gp *tg_pt_gp,
777 	struct se_port *l_port,
778 	struct se_node_acl *nacl,
779 	unsigned char *md_buf,
780 	int new_state,
781 	int explict)
782 {
783 	struct se_dev_entry *se_deve;
784 	struct se_lun_acl *lacl;
785 	struct se_port *port;
786 	struct t10_alua_tg_pt_gp_member *mem;
787 	int old_state = 0;
788 	/*
789 	 * Save the old primary ALUA access state, and set the current state
790 	 * to ALUA_ACCESS_STATE_TRANSITION.
791 	 */
792 	old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
793 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
794 			ALUA_ACCESS_STATE_TRANSITION);
795 	tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
796 				ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
797 				ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
798 	/*
799 	 * Check for the optional ALUA primary state transition delay
800 	 */
801 	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
802 		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
803 
804 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
805 	list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
806 				tg_pt_gp_mem_list) {
807 		port = mem->tg_pt;
808 		/*
809 		 * After an implicit target port asymmetric access state
810 		 * change, a device server shall establish a unit attention
811 		 * condition for the initiator port associated with every I_T
812 		 * nexus with the additional sense code set to ASYMMETRIC
813 		 * ACCESS STATE CHAGED.
814 		 *
815 		 * After an explicit target port asymmetric access state
816 		 * change, a device server shall establish a unit attention
817 		 * condition with the additional sense code set to ASYMMETRIC
818 		 * ACCESS STATE CHANGED for the initiator port associated with
819 		 * every I_T nexus other than the I_T nexus on which the SET
820 		 * TARGET PORT GROUPS command
821 		 */
822 		atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
823 		smp_mb__after_atomic_inc();
824 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
825 
826 		spin_lock_bh(&port->sep_alua_lock);
827 		list_for_each_entry(se_deve, &port->sep_alua_list,
828 					alua_port_list) {
829 			lacl = se_deve->se_lun_acl;
830 			/*
831 			 * se_deve->se_lun_acl pointer may be NULL for a
832 			 * entry created without explict Node+MappedLUN ACLs
833 			 */
834 			if (!lacl)
835 				continue;
836 
837 			if (explict &&
838 			   (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
839 			   (l_port != NULL) && (l_port == port))
840 				continue;
841 
842 			core_scsi3_ua_allocate(lacl->se_lun_nacl,
843 				se_deve->mapped_lun, 0x2A,
844 				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
845 		}
846 		spin_unlock_bh(&port->sep_alua_lock);
847 
848 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
849 		atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
850 		smp_mb__after_atomic_dec();
851 	}
852 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
853 	/*
854 	 * Update the ALUA metadata buf that has been allocated in
855 	 * core_alua_do_port_transition(), this metadata will be written
856 	 * to struct file.
857 	 *
858 	 * Note that there is the case where we do not want to update the
859 	 * metadata when the saved metadata is being parsed in userspace
860 	 * when setting the existing port access state and access status.
861 	 *
862 	 * Also note that the failure to write out the ALUA metadata to
863 	 * struct file does NOT affect the actual ALUA transition.
864 	 */
865 	if (tg_pt_gp->tg_pt_gp_write_metadata) {
866 		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
867 		core_alua_update_tpg_primary_metadata(tg_pt_gp,
868 					new_state, md_buf);
869 		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
870 	}
871 	/*
872 	 * Set the current primary ALUA access state to the requested new state
873 	 */
874 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
875 
876 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
877 		" from primary access state %s to %s\n", (explict) ? "explict" :
878 		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
879 		tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
880 		core_alua_dump_state(new_state));
881 
882 	return 0;
883 }
884 
885 int core_alua_do_port_transition(
886 	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
887 	struct se_device *l_dev,
888 	struct se_port *l_port,
889 	struct se_node_acl *l_nacl,
890 	int new_state,
891 	int explict)
892 {
893 	struct se_device *dev;
894 	struct se_port *port;
895 	struct se_subsystem_dev *su_dev;
896 	struct se_node_acl *nacl;
897 	struct t10_alua_lu_gp *lu_gp;
898 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
899 	struct t10_alua_tg_pt_gp *tg_pt_gp;
900 	unsigned char *md_buf;
901 	int primary;
902 
903 	if (core_alua_check_transition(new_state, &primary) != 0)
904 		return -EINVAL;
905 
906 	md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
907 	if (!md_buf) {
908 		pr_err("Unable to allocate buf for ALUA metadata\n");
909 		return -ENOMEM;
910 	}
911 
912 	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
913 	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
914 	lu_gp = local_lu_gp_mem->lu_gp;
915 	atomic_inc(&lu_gp->lu_gp_ref_cnt);
916 	smp_mb__after_atomic_inc();
917 	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
918 	/*
919 	 * For storage objects that are members of the 'default_lu_gp',
920 	 * we only do transition on the passed *l_tp_pt_gp, and not
921 	 * on all of the matching target port groups IDs in default_lu_gp.
922 	 */
923 	if (!lu_gp->lu_gp_id) {
924 		/*
925 		 * core_alua_do_transition_tg_pt() will always return
926 		 * success.
927 		 */
928 		core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
929 					md_buf, new_state, explict);
930 		atomic_dec(&lu_gp->lu_gp_ref_cnt);
931 		smp_mb__after_atomic_dec();
932 		kfree(md_buf);
933 		return 0;
934 	}
935 	/*
936 	 * For all other LU groups aside from 'default_lu_gp', walk all of
937 	 * the associated storage objects looking for a matching target port
938 	 * group ID from the local target port group.
939 	 */
940 	spin_lock(&lu_gp->lu_gp_lock);
941 	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
942 				lu_gp_mem_list) {
943 
944 		dev = lu_gp_mem->lu_gp_mem_dev;
945 		su_dev = dev->se_sub_dev;
946 		atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
947 		smp_mb__after_atomic_inc();
948 		spin_unlock(&lu_gp->lu_gp_lock);
949 
950 		spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
951 		list_for_each_entry(tg_pt_gp,
952 				&su_dev->t10_alua.tg_pt_gps_list,
953 				tg_pt_gp_list) {
954 
955 			if (!tg_pt_gp->tg_pt_gp_valid_id)
956 				continue;
957 			/*
958 			 * If the target behavior port asymmetric access state
959 			 * is changed for any target port group accessiable via
960 			 * a logical unit within a LU group, the target port
961 			 * behavior group asymmetric access states for the same
962 			 * target port group accessible via other logical units
963 			 * in that LU group will also change.
964 			 */
965 			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
966 				continue;
967 
968 			if (l_tg_pt_gp == tg_pt_gp) {
969 				port = l_port;
970 				nacl = l_nacl;
971 			} else {
972 				port = NULL;
973 				nacl = NULL;
974 			}
975 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
976 			smp_mb__after_atomic_inc();
977 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
978 			/*
979 			 * core_alua_do_transition_tg_pt() will always return
980 			 * success.
981 			 */
982 			core_alua_do_transition_tg_pt(tg_pt_gp, port,
983 					nacl, md_buf, new_state, explict);
984 
985 			spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
986 			atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
987 			smp_mb__after_atomic_dec();
988 		}
989 		spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
990 
991 		spin_lock(&lu_gp->lu_gp_lock);
992 		atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
993 		smp_mb__after_atomic_dec();
994 	}
995 	spin_unlock(&lu_gp->lu_gp_lock);
996 
997 	pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
998 		" Group IDs: %hu %s transition to primary state: %s\n",
999 		config_item_name(&lu_gp->lu_gp_group.cg_item),
1000 		l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
1001 		core_alua_dump_state(new_state));
1002 
1003 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1004 	smp_mb__after_atomic_dec();
1005 	kfree(md_buf);
1006 	return 0;
1007 }
1008 
1009 /*
1010  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
1011  */
1012 static int core_alua_update_tpg_secondary_metadata(
1013 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1014 	struct se_port *port,
1015 	unsigned char *md_buf,
1016 	u32 md_buf_len)
1017 {
1018 	struct se_portal_group *se_tpg = port->sep_tpg;
1019 	char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1020 	int len;
1021 
1022 	memset(path, 0, ALUA_METADATA_PATH_LEN);
1023 	memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1024 
1025 	len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1026 			se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1027 
1028 	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1029 		snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1030 				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1031 
1032 	len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1033 			"alua_tg_pt_status=0x%02x\n",
1034 			atomic_read(&port->sep_tg_pt_secondary_offline),
1035 			port->sep_tg_pt_secondary_stat);
1036 
1037 	snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1038 			se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1039 			port->sep_lun->unpacked_lun);
1040 
1041 	return core_alua_write_tpg_metadata(path, md_buf, len);
1042 }
1043 
1044 static int core_alua_set_tg_pt_secondary_state(
1045 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1046 	struct se_port *port,
1047 	int explict,
1048 	int offline)
1049 {
1050 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1051 	unsigned char *md_buf;
1052 	u32 md_buf_len;
1053 	int trans_delay_msecs;
1054 
1055 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1056 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1057 	if (!tg_pt_gp) {
1058 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1059 		pr_err("Unable to complete secondary state"
1060 				" transition\n");
1061 		return -EINVAL;
1062 	}
1063 	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1064 	/*
1065 	 * Set the secondary ALUA target port access state to OFFLINE
1066 	 * or release the previously secondary state for struct se_port
1067 	 */
1068 	if (offline)
1069 		atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1070 	else
1071 		atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1072 
1073 	md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1074 	port->sep_tg_pt_secondary_stat = (explict) ?
1075 			ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1076 			ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1077 
1078 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1079 		" to secondary access state: %s\n", (explict) ? "explict" :
1080 		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1081 		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1082 
1083 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1084 	/*
1085 	 * Do the optional transition delay after we set the secondary
1086 	 * ALUA access state.
1087 	 */
1088 	if (trans_delay_msecs != 0)
1089 		msleep_interruptible(trans_delay_msecs);
1090 	/*
1091 	 * See if we need to update the ALUA fabric port metadata for
1092 	 * secondary state and status
1093 	 */
1094 	if (port->sep_tg_pt_secondary_write_md) {
1095 		md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1096 		if (!md_buf) {
1097 			pr_err("Unable to allocate md_buf for"
1098 				" secondary ALUA access metadata\n");
1099 			return -ENOMEM;
1100 		}
1101 		mutex_lock(&port->sep_tg_pt_md_mutex);
1102 		core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1103 				md_buf, md_buf_len);
1104 		mutex_unlock(&port->sep_tg_pt_md_mutex);
1105 
1106 		kfree(md_buf);
1107 	}
1108 
1109 	return 0;
1110 }
1111 
1112 struct t10_alua_lu_gp *
1113 core_alua_allocate_lu_gp(const char *name, int def_group)
1114 {
1115 	struct t10_alua_lu_gp *lu_gp;
1116 
1117 	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1118 	if (!lu_gp) {
1119 		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1120 		return ERR_PTR(-ENOMEM);
1121 	}
1122 	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1123 	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1124 	spin_lock_init(&lu_gp->lu_gp_lock);
1125 	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1126 
1127 	if (def_group) {
1128 		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1129 		lu_gp->lu_gp_valid_id = 1;
1130 		alua_lu_gps_count++;
1131 	}
1132 
1133 	return lu_gp;
1134 }
1135 
1136 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1137 {
1138 	struct t10_alua_lu_gp *lu_gp_tmp;
1139 	u16 lu_gp_id_tmp;
1140 	/*
1141 	 * The lu_gp->lu_gp_id may only be set once..
1142 	 */
1143 	if (lu_gp->lu_gp_valid_id) {
1144 		pr_warn("ALUA LU Group already has a valid ID,"
1145 			" ignoring request\n");
1146 		return -EINVAL;
1147 	}
1148 
1149 	spin_lock(&lu_gps_lock);
1150 	if (alua_lu_gps_count == 0x0000ffff) {
1151 		pr_err("Maximum ALUA alua_lu_gps_count:"
1152 				" 0x0000ffff reached\n");
1153 		spin_unlock(&lu_gps_lock);
1154 		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1155 		return -ENOSPC;
1156 	}
1157 again:
1158 	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1159 				alua_lu_gps_counter++;
1160 
1161 	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1162 		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1163 			if (!lu_gp_id)
1164 				goto again;
1165 
1166 			pr_warn("ALUA Logical Unit Group ID: %hu"
1167 				" already exists, ignoring request\n",
1168 				lu_gp_id);
1169 			spin_unlock(&lu_gps_lock);
1170 			return -EINVAL;
1171 		}
1172 	}
1173 
1174 	lu_gp->lu_gp_id = lu_gp_id_tmp;
1175 	lu_gp->lu_gp_valid_id = 1;
1176 	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1177 	alua_lu_gps_count++;
1178 	spin_unlock(&lu_gps_lock);
1179 
1180 	return 0;
1181 }
1182 
1183 static struct t10_alua_lu_gp_member *
1184 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1185 {
1186 	struct t10_alua_lu_gp_member *lu_gp_mem;
1187 
1188 	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1189 	if (!lu_gp_mem) {
1190 		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1191 		return ERR_PTR(-ENOMEM);
1192 	}
1193 	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1194 	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1195 	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1196 
1197 	lu_gp_mem->lu_gp_mem_dev = dev;
1198 	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1199 
1200 	return lu_gp_mem;
1201 }
1202 
1203 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1204 {
1205 	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1206 	/*
1207 	 * Once we have reached this point, config_item_put() has
1208 	 * already been called from target_core_alua_drop_lu_gp().
1209 	 *
1210 	 * Here, we remove the *lu_gp from the global list so that
1211 	 * no associations can be made while we are releasing
1212 	 * struct t10_alua_lu_gp.
1213 	 */
1214 	spin_lock(&lu_gps_lock);
1215 	list_del(&lu_gp->lu_gp_node);
1216 	alua_lu_gps_count--;
1217 	spin_unlock(&lu_gps_lock);
1218 	/*
1219 	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1220 	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1221 	 * released with core_alua_put_lu_gp_from_name()
1222 	 */
1223 	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1224 		cpu_relax();
1225 	/*
1226 	 * Release reference to struct t10_alua_lu_gp * from all associated
1227 	 * struct se_device.
1228 	 */
1229 	spin_lock(&lu_gp->lu_gp_lock);
1230 	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1231 				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1232 		if (lu_gp_mem->lu_gp_assoc) {
1233 			list_del(&lu_gp_mem->lu_gp_mem_list);
1234 			lu_gp->lu_gp_members--;
1235 			lu_gp_mem->lu_gp_assoc = 0;
1236 		}
1237 		spin_unlock(&lu_gp->lu_gp_lock);
1238 		/*
1239 		 *
1240 		 * lu_gp_mem is associated with a single
1241 		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1242 		 * struct se_device is released via core_alua_free_lu_gp_mem().
1243 		 *
1244 		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1245 		 * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1246 		 */
1247 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1248 		if (lu_gp != default_lu_gp)
1249 			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1250 					default_lu_gp);
1251 		else
1252 			lu_gp_mem->lu_gp = NULL;
1253 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1254 
1255 		spin_lock(&lu_gp->lu_gp_lock);
1256 	}
1257 	spin_unlock(&lu_gp->lu_gp_lock);
1258 
1259 	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1260 }
1261 
1262 void core_alua_free_lu_gp_mem(struct se_device *dev)
1263 {
1264 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1265 	struct t10_alua *alua = &su_dev->t10_alua;
1266 	struct t10_alua_lu_gp *lu_gp;
1267 	struct t10_alua_lu_gp_member *lu_gp_mem;
1268 
1269 	if (alua->alua_type != SPC3_ALUA_EMULATED)
1270 		return;
1271 
1272 	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1273 	if (!lu_gp_mem)
1274 		return;
1275 
1276 	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1277 		cpu_relax();
1278 
1279 	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1280 	lu_gp = lu_gp_mem->lu_gp;
1281 	if (lu_gp) {
1282 		spin_lock(&lu_gp->lu_gp_lock);
1283 		if (lu_gp_mem->lu_gp_assoc) {
1284 			list_del(&lu_gp_mem->lu_gp_mem_list);
1285 			lu_gp->lu_gp_members--;
1286 			lu_gp_mem->lu_gp_assoc = 0;
1287 		}
1288 		spin_unlock(&lu_gp->lu_gp_lock);
1289 		lu_gp_mem->lu_gp = NULL;
1290 	}
1291 	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1292 
1293 	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1294 }
1295 
1296 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1297 {
1298 	struct t10_alua_lu_gp *lu_gp;
1299 	struct config_item *ci;
1300 
1301 	spin_lock(&lu_gps_lock);
1302 	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1303 		if (!lu_gp->lu_gp_valid_id)
1304 			continue;
1305 		ci = &lu_gp->lu_gp_group.cg_item;
1306 		if (!strcmp(config_item_name(ci), name)) {
1307 			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1308 			spin_unlock(&lu_gps_lock);
1309 			return lu_gp;
1310 		}
1311 	}
1312 	spin_unlock(&lu_gps_lock);
1313 
1314 	return NULL;
1315 }
1316 
1317 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1318 {
1319 	spin_lock(&lu_gps_lock);
1320 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1321 	spin_unlock(&lu_gps_lock);
1322 }
1323 
1324 /*
1325  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1326  */
1327 void __core_alua_attach_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 	lu_gp_mem->lu_gp = lu_gp;
1333 	lu_gp_mem->lu_gp_assoc = 1;
1334 	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1335 	lu_gp->lu_gp_members++;
1336 	spin_unlock(&lu_gp->lu_gp_lock);
1337 }
1338 
1339 /*
1340  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1341  */
1342 void __core_alua_drop_lu_gp_mem(
1343 	struct t10_alua_lu_gp_member *lu_gp_mem,
1344 	struct t10_alua_lu_gp *lu_gp)
1345 {
1346 	spin_lock(&lu_gp->lu_gp_lock);
1347 	list_del(&lu_gp_mem->lu_gp_mem_list);
1348 	lu_gp_mem->lu_gp = NULL;
1349 	lu_gp_mem->lu_gp_assoc = 0;
1350 	lu_gp->lu_gp_members--;
1351 	spin_unlock(&lu_gp->lu_gp_lock);
1352 }
1353 
1354 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1355 	struct se_subsystem_dev *su_dev,
1356 	const char *name,
1357 	int def_group)
1358 {
1359 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1360 
1361 	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1362 	if (!tg_pt_gp) {
1363 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1364 		return NULL;
1365 	}
1366 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1367 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1368 	mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1369 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1370 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1371 	tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1372 	tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1373 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1374 		ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1375 	/*
1376 	 * Enable both explict and implict ALUA support by default
1377 	 */
1378 	tg_pt_gp->tg_pt_gp_alua_access_type =
1379 			TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1380 	/*
1381 	 * Set the default Active/NonOptimized Delay in milliseconds
1382 	 */
1383 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1384 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1385 	tg_pt_gp->tg_pt_gp_implict_trans_secs = ALUA_DEFAULT_IMPLICT_TRANS_SECS;
1386 
1387 	if (def_group) {
1388 		spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1389 		tg_pt_gp->tg_pt_gp_id =
1390 				su_dev->t10_alua.alua_tg_pt_gps_counter++;
1391 		tg_pt_gp->tg_pt_gp_valid_id = 1;
1392 		su_dev->t10_alua.alua_tg_pt_gps_count++;
1393 		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1394 			      &su_dev->t10_alua.tg_pt_gps_list);
1395 		spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1396 	}
1397 
1398 	return tg_pt_gp;
1399 }
1400 
1401 int core_alua_set_tg_pt_gp_id(
1402 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1403 	u16 tg_pt_gp_id)
1404 {
1405 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1406 	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1407 	u16 tg_pt_gp_id_tmp;
1408 	/*
1409 	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1410 	 */
1411 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1412 		pr_warn("ALUA TG PT Group already has a valid ID,"
1413 			" ignoring request\n");
1414 		return -EINVAL;
1415 	}
1416 
1417 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1418 	if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1419 		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1420 			" 0x0000ffff reached\n");
1421 		spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1422 		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1423 		return -ENOSPC;
1424 	}
1425 again:
1426 	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1427 			su_dev->t10_alua.alua_tg_pt_gps_counter++;
1428 
1429 	list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1430 			tg_pt_gp_list) {
1431 		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1432 			if (!tg_pt_gp_id)
1433 				goto again;
1434 
1435 			pr_err("ALUA Target Port Group ID: %hu already"
1436 				" exists, ignoring request\n", tg_pt_gp_id);
1437 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1438 			return -EINVAL;
1439 		}
1440 	}
1441 
1442 	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1443 	tg_pt_gp->tg_pt_gp_valid_id = 1;
1444 	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1445 			&su_dev->t10_alua.tg_pt_gps_list);
1446 	su_dev->t10_alua.alua_tg_pt_gps_count++;
1447 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1448 
1449 	return 0;
1450 }
1451 
1452 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1453 	struct se_port *port)
1454 {
1455 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1456 
1457 	tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1458 				GFP_KERNEL);
1459 	if (!tg_pt_gp_mem) {
1460 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1461 		return ERR_PTR(-ENOMEM);
1462 	}
1463 	INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1464 	spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1465 	atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1466 
1467 	tg_pt_gp_mem->tg_pt = port;
1468 	port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1469 
1470 	return tg_pt_gp_mem;
1471 }
1472 
1473 void core_alua_free_tg_pt_gp(
1474 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1475 {
1476 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1477 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1478 	/*
1479 	 * Once we have reached this point, config_item_put() has already
1480 	 * been called from target_core_alua_drop_tg_pt_gp().
1481 	 *
1482 	 * Here we remove *tg_pt_gp from the global list so that
1483 	 * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1484 	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1485 	 */
1486 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1487 	list_del(&tg_pt_gp->tg_pt_gp_list);
1488 	su_dev->t10_alua.alua_tg_pt_gps_counter--;
1489 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1490 	/*
1491 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1492 	 * core_alua_get_tg_pt_gp_by_name() in
1493 	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1494 	 * to be released with core_alua_put_tg_pt_gp_from_name().
1495 	 */
1496 	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1497 		cpu_relax();
1498 	/*
1499 	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1500 	 * struct se_port.
1501 	 */
1502 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1503 	list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1504 			&tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1505 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1506 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1507 			tg_pt_gp->tg_pt_gp_members--;
1508 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1509 		}
1510 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1511 		/*
1512 		 * tg_pt_gp_mem is associated with a single
1513 		 * se_port->sep_alua_tg_pt_gp_mem, and is released via
1514 		 * core_alua_free_tg_pt_gp_mem().
1515 		 *
1516 		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1517 		 * assume we want to re-assocate a given tg_pt_gp_mem with
1518 		 * default_tg_pt_gp.
1519 		 */
1520 		spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1521 		if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1522 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1523 					su_dev->t10_alua.default_tg_pt_gp);
1524 		} else
1525 			tg_pt_gp_mem->tg_pt_gp = NULL;
1526 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1527 
1528 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1529 	}
1530 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1531 
1532 	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1533 }
1534 
1535 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1536 {
1537 	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1538 	struct t10_alua *alua = &su_dev->t10_alua;
1539 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1540 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1541 
1542 	if (alua->alua_type != SPC3_ALUA_EMULATED)
1543 		return;
1544 
1545 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1546 	if (!tg_pt_gp_mem)
1547 		return;
1548 
1549 	while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1550 		cpu_relax();
1551 
1552 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1553 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1554 	if (tg_pt_gp) {
1555 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1556 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1557 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1558 			tg_pt_gp->tg_pt_gp_members--;
1559 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1560 		}
1561 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1562 		tg_pt_gp_mem->tg_pt_gp = NULL;
1563 	}
1564 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1565 
1566 	kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1567 }
1568 
1569 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1570 	struct se_subsystem_dev *su_dev,
1571 	const char *name)
1572 {
1573 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1574 	struct config_item *ci;
1575 
1576 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1577 	list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1578 			tg_pt_gp_list) {
1579 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1580 			continue;
1581 		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1582 		if (!strcmp(config_item_name(ci), name)) {
1583 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1584 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1585 			return tg_pt_gp;
1586 		}
1587 	}
1588 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1589 
1590 	return NULL;
1591 }
1592 
1593 static void core_alua_put_tg_pt_gp_from_name(
1594 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1595 {
1596 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1597 
1598 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1599 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1600 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1601 }
1602 
1603 /*
1604  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1605  */
1606 void __core_alua_attach_tg_pt_gp_mem(
1607 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1608 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1609 {
1610 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1611 	tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1612 	tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1613 	list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1614 			&tg_pt_gp->tg_pt_gp_mem_list);
1615 	tg_pt_gp->tg_pt_gp_members++;
1616 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1617 }
1618 
1619 /*
1620  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1621  */
1622 static void __core_alua_drop_tg_pt_gp_mem(
1623 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1624 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1625 {
1626 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1627 	list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1628 	tg_pt_gp_mem->tg_pt_gp = NULL;
1629 	tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1630 	tg_pt_gp->tg_pt_gp_members--;
1631 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1632 }
1633 
1634 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1635 {
1636 	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1637 	struct config_item *tg_pt_ci;
1638 	struct t10_alua *alua = &su_dev->t10_alua;
1639 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1640 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1641 	ssize_t len = 0;
1642 
1643 	if (alua->alua_type != SPC3_ALUA_EMULATED)
1644 		return len;
1645 
1646 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1647 	if (!tg_pt_gp_mem)
1648 		return len;
1649 
1650 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1651 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1652 	if (tg_pt_gp) {
1653 		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1654 		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1655 			" %hu\nTG Port Primary Access State: %s\nTG Port "
1656 			"Primary Access Status: %s\nTG Port Secondary Access"
1657 			" State: %s\nTG Port Secondary Access Status: %s\n",
1658 			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1659 			core_alua_dump_state(atomic_read(
1660 					&tg_pt_gp->tg_pt_gp_alua_access_state)),
1661 			core_alua_dump_status(
1662 				tg_pt_gp->tg_pt_gp_alua_access_status),
1663 			(atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1664 			"Offline" : "None",
1665 			core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1666 	}
1667 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1668 
1669 	return len;
1670 }
1671 
1672 ssize_t core_alua_store_tg_pt_gp_info(
1673 	struct se_port *port,
1674 	const char *page,
1675 	size_t count)
1676 {
1677 	struct se_portal_group *tpg;
1678 	struct se_lun *lun;
1679 	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1680 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1681 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1682 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1683 	int move = 0;
1684 
1685 	tpg = port->sep_tpg;
1686 	lun = port->sep_lun;
1687 
1688 	if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1689 		pr_warn("SPC3_ALUA_EMULATED not enabled for"
1690 			" %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1691 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1692 			config_item_name(&lun->lun_group.cg_item));
1693 		return -EINVAL;
1694 	}
1695 
1696 	if (count > TG_PT_GROUP_NAME_BUF) {
1697 		pr_err("ALUA Target Port Group alias too large!\n");
1698 		return -EINVAL;
1699 	}
1700 	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1701 	memcpy(buf, page, count);
1702 	/*
1703 	 * Any ALUA target port group alias besides "NULL" means we will be
1704 	 * making a new group association.
1705 	 */
1706 	if (strcmp(strstrip(buf), "NULL")) {
1707 		/*
1708 		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1709 		 * struct t10_alua_tg_pt_gp.  This reference is released with
1710 		 * core_alua_put_tg_pt_gp_from_name() below.
1711 		 */
1712 		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1713 					strstrip(buf));
1714 		if (!tg_pt_gp_new)
1715 			return -ENODEV;
1716 	}
1717 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1718 	if (!tg_pt_gp_mem) {
1719 		if (tg_pt_gp_new)
1720 			core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1721 		pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1722 		return -EINVAL;
1723 	}
1724 
1725 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1726 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1727 	if (tg_pt_gp) {
1728 		/*
1729 		 * Clearing an existing tg_pt_gp association, and replacing
1730 		 * with the default_tg_pt_gp.
1731 		 */
1732 		if (!tg_pt_gp_new) {
1733 			pr_debug("Target_Core_ConfigFS: Moving"
1734 				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
1735 				" alua/%s, ID: %hu back to"
1736 				" default_tg_pt_gp\n",
1737 				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1738 				tpg->se_tpg_tfo->tpg_get_tag(tpg),
1739 				config_item_name(&lun->lun_group.cg_item),
1740 				config_item_name(
1741 					&tg_pt_gp->tg_pt_gp_group.cg_item),
1742 				tg_pt_gp->tg_pt_gp_id);
1743 
1744 			__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1745 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1746 					su_dev->t10_alua.default_tg_pt_gp);
1747 			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1748 
1749 			return count;
1750 		}
1751 		/*
1752 		 * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1753 		 */
1754 		__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1755 		move = 1;
1756 	}
1757 	/*
1758 	 * Associate tg_pt_gp_mem with tg_pt_gp_new.
1759 	 */
1760 	__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1761 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1762 	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1763 		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
1764 		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1765 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
1766 		config_item_name(&lun->lun_group.cg_item),
1767 		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1768 		tg_pt_gp_new->tg_pt_gp_id);
1769 
1770 	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1771 	return count;
1772 }
1773 
1774 ssize_t core_alua_show_access_type(
1775 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1776 	char *page)
1777 {
1778 	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1779 	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1780 		return sprintf(page, "Implict and Explict\n");
1781 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1782 		return sprintf(page, "Implict\n");
1783 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1784 		return sprintf(page, "Explict\n");
1785 	else
1786 		return sprintf(page, "None\n");
1787 }
1788 
1789 ssize_t core_alua_store_access_type(
1790 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1791 	const char *page,
1792 	size_t count)
1793 {
1794 	unsigned long tmp;
1795 	int ret;
1796 
1797 	ret = strict_strtoul(page, 0, &tmp);
1798 	if (ret < 0) {
1799 		pr_err("Unable to extract alua_access_type\n");
1800 		return -EINVAL;
1801 	}
1802 	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1803 		pr_err("Illegal value for alua_access_type:"
1804 				" %lu\n", tmp);
1805 		return -EINVAL;
1806 	}
1807 	if (tmp == 3)
1808 		tg_pt_gp->tg_pt_gp_alua_access_type =
1809 			TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1810 	else if (tmp == 2)
1811 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1812 	else if (tmp == 1)
1813 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1814 	else
1815 		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1816 
1817 	return count;
1818 }
1819 
1820 ssize_t core_alua_show_nonop_delay_msecs(
1821 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1822 	char *page)
1823 {
1824 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1825 }
1826 
1827 ssize_t core_alua_store_nonop_delay_msecs(
1828 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1829 	const char *page,
1830 	size_t count)
1831 {
1832 	unsigned long tmp;
1833 	int ret;
1834 
1835 	ret = strict_strtoul(page, 0, &tmp);
1836 	if (ret < 0) {
1837 		pr_err("Unable to extract nonop_delay_msecs\n");
1838 		return -EINVAL;
1839 	}
1840 	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1841 		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1842 			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1843 			ALUA_MAX_NONOP_DELAY_MSECS);
1844 		return -EINVAL;
1845 	}
1846 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1847 
1848 	return count;
1849 }
1850 
1851 ssize_t core_alua_show_trans_delay_msecs(
1852 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1853 	char *page)
1854 {
1855 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1856 }
1857 
1858 ssize_t core_alua_store_trans_delay_msecs(
1859 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1860 	const char *page,
1861 	size_t count)
1862 {
1863 	unsigned long tmp;
1864 	int ret;
1865 
1866 	ret = strict_strtoul(page, 0, &tmp);
1867 	if (ret < 0) {
1868 		pr_err("Unable to extract trans_delay_msecs\n");
1869 		return -EINVAL;
1870 	}
1871 	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1872 		pr_err("Passed trans_delay_msecs: %lu, exceeds"
1873 			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1874 			ALUA_MAX_TRANS_DELAY_MSECS);
1875 		return -EINVAL;
1876 	}
1877 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1878 
1879 	return count;
1880 }
1881 
1882 ssize_t core_alua_show_implict_trans_secs(
1883 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1884 	char *page)
1885 {
1886 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implict_trans_secs);
1887 }
1888 
1889 ssize_t core_alua_store_implict_trans_secs(
1890 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1891 	const char *page,
1892 	size_t count)
1893 {
1894 	unsigned long tmp;
1895 	int ret;
1896 
1897 	ret = strict_strtoul(page, 0, &tmp);
1898 	if (ret < 0) {
1899 		pr_err("Unable to extract implict_trans_secs\n");
1900 		return -EINVAL;
1901 	}
1902 	if (tmp > ALUA_MAX_IMPLICT_TRANS_SECS) {
1903 		pr_err("Passed implict_trans_secs: %lu, exceeds"
1904 			" ALUA_MAX_IMPLICT_TRANS_SECS: %d\n", tmp,
1905 			ALUA_MAX_IMPLICT_TRANS_SECS);
1906 		return  -EINVAL;
1907 	}
1908 	tg_pt_gp->tg_pt_gp_implict_trans_secs = (int)tmp;
1909 
1910 	return count;
1911 }
1912 
1913 ssize_t core_alua_show_preferred_bit(
1914 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1915 	char *page)
1916 {
1917 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1918 }
1919 
1920 ssize_t core_alua_store_preferred_bit(
1921 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1922 	const char *page,
1923 	size_t count)
1924 {
1925 	unsigned long tmp;
1926 	int ret;
1927 
1928 	ret = strict_strtoul(page, 0, &tmp);
1929 	if (ret < 0) {
1930 		pr_err("Unable to extract preferred ALUA value\n");
1931 		return -EINVAL;
1932 	}
1933 	if ((tmp != 0) && (tmp != 1)) {
1934 		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1935 		return -EINVAL;
1936 	}
1937 	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1938 
1939 	return count;
1940 }
1941 
1942 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1943 {
1944 	if (!lun->lun_sep)
1945 		return -ENODEV;
1946 
1947 	return sprintf(page, "%d\n",
1948 		atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1949 }
1950 
1951 ssize_t core_alua_store_offline_bit(
1952 	struct se_lun *lun,
1953 	const char *page,
1954 	size_t count)
1955 {
1956 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1957 	unsigned long tmp;
1958 	int ret;
1959 
1960 	if (!lun->lun_sep)
1961 		return -ENODEV;
1962 
1963 	ret = strict_strtoul(page, 0, &tmp);
1964 	if (ret < 0) {
1965 		pr_err("Unable to extract alua_tg_pt_offline value\n");
1966 		return -EINVAL;
1967 	}
1968 	if ((tmp != 0) && (tmp != 1)) {
1969 		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1970 				tmp);
1971 		return -EINVAL;
1972 	}
1973 	tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1974 	if (!tg_pt_gp_mem) {
1975 		pr_err("Unable to locate *tg_pt_gp_mem\n");
1976 		return -EINVAL;
1977 	}
1978 
1979 	ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1980 			lun->lun_sep, 0, (int)tmp);
1981 	if (ret < 0)
1982 		return -EINVAL;
1983 
1984 	return count;
1985 }
1986 
1987 ssize_t core_alua_show_secondary_status(
1988 	struct se_lun *lun,
1989 	char *page)
1990 {
1991 	return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1992 }
1993 
1994 ssize_t core_alua_store_secondary_status(
1995 	struct se_lun *lun,
1996 	const char *page,
1997 	size_t count)
1998 {
1999 	unsigned long tmp;
2000 	int ret;
2001 
2002 	ret = strict_strtoul(page, 0, &tmp);
2003 	if (ret < 0) {
2004 		pr_err("Unable to extract alua_tg_pt_status\n");
2005 		return -EINVAL;
2006 	}
2007 	if ((tmp != ALUA_STATUS_NONE) &&
2008 	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
2009 	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
2010 		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2011 				tmp);
2012 		return -EINVAL;
2013 	}
2014 	lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
2015 
2016 	return count;
2017 }
2018 
2019 ssize_t core_alua_show_secondary_write_metadata(
2020 	struct se_lun *lun,
2021 	char *page)
2022 {
2023 	return sprintf(page, "%d\n",
2024 			lun->lun_sep->sep_tg_pt_secondary_write_md);
2025 }
2026 
2027 ssize_t core_alua_store_secondary_write_metadata(
2028 	struct se_lun *lun,
2029 	const char *page,
2030 	size_t count)
2031 {
2032 	unsigned long tmp;
2033 	int ret;
2034 
2035 	ret = strict_strtoul(page, 0, &tmp);
2036 	if (ret < 0) {
2037 		pr_err("Unable to extract alua_tg_pt_write_md\n");
2038 		return -EINVAL;
2039 	}
2040 	if ((tmp != 0) && (tmp != 1)) {
2041 		pr_err("Illegal value for alua_tg_pt_write_md:"
2042 				" %lu\n", tmp);
2043 		return -EINVAL;
2044 	}
2045 	lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
2046 
2047 	return count;
2048 }
2049 
2050 int core_setup_alua(struct se_device *dev, int force_pt)
2051 {
2052 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
2053 	struct t10_alua *alua = &su_dev->t10_alua;
2054 	struct t10_alua_lu_gp_member *lu_gp_mem;
2055 	/*
2056 	 * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
2057 	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2058 	 * cause a problem because libata and some SATA RAID HBAs appear
2059 	 * under Linux/SCSI, but emulate SCSI logic themselves.
2060 	 */
2061 	if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2062 	    !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2063 		alua->alua_type = SPC_ALUA_PASSTHROUGH;
2064 		alua->alua_state_check = &core_alua_state_check_nop;
2065 		pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2066 			" emulation\n", dev->transport->name);
2067 		return 0;
2068 	}
2069 	/*
2070 	 * If SPC-3 or above is reported by real or emulated struct se_device,
2071 	 * use emulated ALUA.
2072 	 */
2073 	if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2074 		pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2075 			" device\n", dev->transport->name);
2076 		/*
2077 		 * Associate this struct se_device with the default ALUA
2078 		 * LUN Group.
2079 		 */
2080 		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2081 		if (IS_ERR(lu_gp_mem))
2082 			return PTR_ERR(lu_gp_mem);
2083 
2084 		alua->alua_type = SPC3_ALUA_EMULATED;
2085 		alua->alua_state_check = &core_alua_state_check;
2086 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2087 		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2088 				default_lu_gp);
2089 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2090 
2091 		pr_debug("%s: Adding to default ALUA LU Group:"
2092 			" core/alua/lu_gps/default_lu_gp\n",
2093 			dev->transport->name);
2094 	} else {
2095 		alua->alua_type = SPC2_ALUA_DISABLED;
2096 		alua->alua_state_check = &core_alua_state_check_nop;
2097 		pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2098 			" device\n", dev->transport->name);
2099 	}
2100 
2101 	return 0;
2102 }
2103