xref: /linux/drivers/target/target_core_alua.c (revision 7056741fd9fc14a65608549a4657cf5178f05f63)
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 	if (cmd->data_length < 4) {
222 		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
223 			" small\n", cmd->data_length);
224 		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
225 		return -EINVAL;
226 	}
227 
228 	buf = transport_kmap_data_sg(cmd);
229 
230 	/*
231 	 * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
232 	 * for the local tg_pt_gp.
233 	 */
234 	l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
235 	if (!l_tg_pt_gp_mem) {
236 		pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
237 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
238 		rc = -EINVAL;
239 		goto out;
240 	}
241 	spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
242 	l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
243 	if (!l_tg_pt_gp) {
244 		spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
245 		pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
246 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
247 		rc = -EINVAL;
248 		goto out;
249 	}
250 	rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
251 	spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
252 
253 	if (!rc) {
254 		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
255 				" while TPGS_EXPLICT_ALUA is disabled\n");
256 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
257 		rc = -EINVAL;
258 		goto out;
259 	}
260 
261 	ptr = &buf[4]; /* Skip over RESERVED area in header */
262 
263 	while (len < cmd->data_length) {
264 		alua_access_state = (ptr[0] & 0x0f);
265 		/*
266 		 * Check the received ALUA access state, and determine if
267 		 * the state is a primary or secondary target port asymmetric
268 		 * access state.
269 		 */
270 		rc = core_alua_check_transition(alua_access_state, &primary);
271 		if (rc != 0) {
272 			/*
273 			 * If the SET TARGET PORT GROUPS attempts to establish
274 			 * an invalid combination of target port asymmetric
275 			 * access states or attempts to establish an
276 			 * unsupported target port asymmetric access state,
277 			 * then the command shall be terminated with CHECK
278 			 * CONDITION status, with the sense key set to ILLEGAL
279 			 * REQUEST, and the additional sense code set to INVALID
280 			 * FIELD IN PARAMETER LIST.
281 			 */
282 			cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
283 			rc = -EINVAL;
284 			goto out;
285 		}
286 		rc = -1;
287 		/*
288 		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
289 		 * specifies a primary target port asymmetric access state,
290 		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
291 		 * a primary target port group for which the primary target
292 		 * port asymmetric access state shall be changed. If the
293 		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
294 		 * port asymmetric access state, then the TARGET PORT GROUP OR
295 		 * TARGET PORT field specifies the relative target port
296 		 * identifier (see 3.1.120) of the target port for which the
297 		 * secondary target port asymmetric access state shall be
298 		 * changed.
299 		 */
300 		if (primary) {
301 			tg_pt_id = get_unaligned_be16(ptr + 2);
302 			/*
303 			 * Locate the matching target port group ID from
304 			 * the global tg_pt_gp list
305 			 */
306 			spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
307 			list_for_each_entry(tg_pt_gp,
308 					&su_dev->t10_alua.tg_pt_gps_list,
309 					tg_pt_gp_list) {
310 				if (!tg_pt_gp->tg_pt_gp_valid_id)
311 					continue;
312 
313 				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
314 					continue;
315 
316 				atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
317 				smp_mb__after_atomic_inc();
318 				spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
319 
320 				rc = core_alua_do_port_transition(tg_pt_gp,
321 						dev, l_port, nacl,
322 						alua_access_state, 1);
323 
324 				spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
325 				atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
326 				smp_mb__after_atomic_dec();
327 				break;
328 			}
329 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
330 			/*
331 			 * If not matching target port group ID can be located
332 			 * throw an exception with ASCQ: INVALID_PARAMETER_LIST
333 			 */
334 			if (rc != 0) {
335 				cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
336 				rc = -EINVAL;
337 				goto out;
338 			}
339 		} else {
340 			/*
341 			 * Extact the RELATIVE TARGET PORT IDENTIFIER to identify
342 			 * the Target Port in question for the the incoming
343 			 * SET_TARGET_PORT_GROUPS op.
344 			 */
345 			rtpi = get_unaligned_be16(ptr + 2);
346 			/*
347 			 * Locate the matching relative target port identifier
348 			 * for the struct se_device storage object.
349 			 */
350 			spin_lock(&dev->se_port_lock);
351 			list_for_each_entry(port, &dev->dev_sep_list,
352 							sep_list) {
353 				if (port->sep_rtpi != rtpi)
354 					continue;
355 
356 				tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
357 				spin_unlock(&dev->se_port_lock);
358 
359 				rc = core_alua_set_tg_pt_secondary_state(
360 						tg_pt_gp_mem, port, 1, 1);
361 
362 				spin_lock(&dev->se_port_lock);
363 				break;
364 			}
365 			spin_unlock(&dev->se_port_lock);
366 			/*
367 			 * If not matching relative target port identifier can
368 			 * be located, throw an exception with ASCQ:
369 			 * INVALID_PARAMETER_LIST
370 			 */
371 			if (rc != 0) {
372 				cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
373 				rc = -EINVAL;
374 				goto out;
375 			}
376 		}
377 
378 		ptr += 4;
379 		len += 4;
380 	}
381 
382 out:
383 	transport_kunmap_data_sg(cmd);
384 	if (!rc)
385 		target_complete_cmd(cmd, GOOD);
386 	return rc;
387 }
388 
389 static inline int core_alua_state_nonoptimized(
390 	struct se_cmd *cmd,
391 	unsigned char *cdb,
392 	int nonop_delay_msecs,
393 	u8 *alua_ascq)
394 {
395 	/*
396 	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
397 	 * later to determine if processing of this cmd needs to be
398 	 * temporarily delayed for the Active/NonOptimized primary access state.
399 	 */
400 	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
401 	cmd->alua_nonop_delay = nonop_delay_msecs;
402 	return 0;
403 }
404 
405 static inline int core_alua_state_standby(
406 	struct se_cmd *cmd,
407 	unsigned char *cdb,
408 	u8 *alua_ascq)
409 {
410 	/*
411 	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
412 	 * spc4r17 section 5.9.2.4.4
413 	 */
414 	switch (cdb[0]) {
415 	case INQUIRY:
416 	case LOG_SELECT:
417 	case LOG_SENSE:
418 	case MODE_SELECT:
419 	case MODE_SENSE:
420 	case REPORT_LUNS:
421 	case RECEIVE_DIAGNOSTIC:
422 	case SEND_DIAGNOSTIC:
423 	case MAINTENANCE_IN:
424 		switch (cdb[1] & 0x1f) {
425 		case MI_REPORT_TARGET_PGS:
426 			return 0;
427 		default:
428 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
429 			return 1;
430 		}
431 	case MAINTENANCE_OUT:
432 		switch (cdb[1]) {
433 		case MO_SET_TARGET_PGS:
434 			return 0;
435 		default:
436 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
437 			return 1;
438 		}
439 	case REQUEST_SENSE:
440 	case PERSISTENT_RESERVE_IN:
441 	case PERSISTENT_RESERVE_OUT:
442 	case READ_BUFFER:
443 	case WRITE_BUFFER:
444 		return 0;
445 	default:
446 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
447 		return 1;
448 	}
449 
450 	return 0;
451 }
452 
453 static inline int core_alua_state_unavailable(
454 	struct se_cmd *cmd,
455 	unsigned char *cdb,
456 	u8 *alua_ascq)
457 {
458 	/*
459 	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
460 	 * spc4r17 section 5.9.2.4.5
461 	 */
462 	switch (cdb[0]) {
463 	case INQUIRY:
464 	case REPORT_LUNS:
465 	case MAINTENANCE_IN:
466 		switch (cdb[1] & 0x1f) {
467 		case MI_REPORT_TARGET_PGS:
468 			return 0;
469 		default:
470 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
471 			return 1;
472 		}
473 	case MAINTENANCE_OUT:
474 		switch (cdb[1]) {
475 		case MO_SET_TARGET_PGS:
476 			return 0;
477 		default:
478 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
479 			return 1;
480 		}
481 	case REQUEST_SENSE:
482 	case READ_BUFFER:
483 	case WRITE_BUFFER:
484 		return 0;
485 	default:
486 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
487 		return 1;
488 	}
489 
490 	return 0;
491 }
492 
493 static inline int core_alua_state_transition(
494 	struct se_cmd *cmd,
495 	unsigned char *cdb,
496 	u8 *alua_ascq)
497 {
498 	/*
499 	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
500 	 * spc4r17 section 5.9.2.5
501 	 */
502 	switch (cdb[0]) {
503 	case INQUIRY:
504 	case REPORT_LUNS:
505 	case MAINTENANCE_IN:
506 		switch (cdb[1] & 0x1f) {
507 		case MI_REPORT_TARGET_PGS:
508 			return 0;
509 		default:
510 			*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
511 			return 1;
512 		}
513 	case REQUEST_SENSE:
514 	case READ_BUFFER:
515 	case WRITE_BUFFER:
516 		return 0;
517 	default:
518 		*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
519 		return 1;
520 	}
521 
522 	return 0;
523 }
524 
525 /*
526  * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
527  * in transport_cmd_sequencer().  This function is assigned to
528  * struct t10_alua *->state_check() in core_setup_alua()
529  */
530 static int core_alua_state_check_nop(
531 	struct se_cmd *cmd,
532 	unsigned char *cdb,
533 	u8 *alua_ascq)
534 {
535 	return 0;
536 }
537 
538 /*
539  * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
540  * This function is assigned to struct t10_alua *->state_check() in
541  * core_setup_alua()
542  *
543  * Also, this function can return three different return codes to
544  * signal transport_generic_cmd_sequencer()
545  *
546  * return 1: Is used to signal LUN not accecsable, and check condition/not ready
547  * return 0: Used to signal success
548  * reutrn -1: Used to signal failure, and invalid cdb field
549  */
550 static int core_alua_state_check(
551 	struct se_cmd *cmd,
552 	unsigned char *cdb,
553 	u8 *alua_ascq)
554 {
555 	struct se_lun *lun = cmd->se_lun;
556 	struct se_port *port = lun->lun_sep;
557 	struct t10_alua_tg_pt_gp *tg_pt_gp;
558 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
559 	int out_alua_state, nonop_delay_msecs;
560 
561 	if (!port)
562 		return 0;
563 	/*
564 	 * First, check for a struct se_port specific secondary ALUA target port
565 	 * access state: OFFLINE
566 	 */
567 	if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
568 		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
569 		pr_debug("ALUA: Got secondary offline status for local"
570 				" target port\n");
571 		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
572 		return 1;
573 	}
574 	 /*
575 	 * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
576 	 * ALUA target port group, to obtain current ALUA access state.
577 	 * Otherwise look for the underlying struct se_device association with
578 	 * a ALUA logical unit group.
579 	 */
580 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
581 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
582 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
583 	out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
584 	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
585 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
586 	/*
587 	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
588 	 * statement so the compiler knows explicitly to check this case first.
589 	 * For the Optimized ALUA access state case, we want to process the
590 	 * incoming fabric cmd ASAP..
591 	 */
592 	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
593 		return 0;
594 
595 	switch (out_alua_state) {
596 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
597 		return core_alua_state_nonoptimized(cmd, cdb,
598 					nonop_delay_msecs, alua_ascq);
599 	case ALUA_ACCESS_STATE_STANDBY:
600 		return core_alua_state_standby(cmd, cdb, alua_ascq);
601 	case ALUA_ACCESS_STATE_UNAVAILABLE:
602 		return core_alua_state_unavailable(cmd, cdb, alua_ascq);
603 	case ALUA_ACCESS_STATE_TRANSITION:
604 		return core_alua_state_transition(cmd, cdb, alua_ascq);
605 	/*
606 	 * OFFLINE is a secondary ALUA target port group access state, that is
607 	 * handled above with struct se_port->sep_tg_pt_secondary_offline=1
608 	 */
609 	case ALUA_ACCESS_STATE_OFFLINE:
610 	default:
611 		pr_err("Unknown ALUA access state: 0x%02x\n",
612 				out_alua_state);
613 		return -EINVAL;
614 	}
615 
616 	return 0;
617 }
618 
619 /*
620  * Check implict and explict ALUA state change request.
621  */
622 static int core_alua_check_transition(int state, int *primary)
623 {
624 	switch (state) {
625 	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
626 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
627 	case ALUA_ACCESS_STATE_STANDBY:
628 	case ALUA_ACCESS_STATE_UNAVAILABLE:
629 		/*
630 		 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
631 		 * defined as primary target port asymmetric access states.
632 		 */
633 		*primary = 1;
634 		break;
635 	case ALUA_ACCESS_STATE_OFFLINE:
636 		/*
637 		 * OFFLINE state is defined as a secondary target port
638 		 * asymmetric access state.
639 		 */
640 		*primary = 0;
641 		break;
642 	default:
643 		pr_err("Unknown ALUA access state: 0x%02x\n", state);
644 		return -EINVAL;
645 	}
646 
647 	return 0;
648 }
649 
650 static char *core_alua_dump_state(int state)
651 {
652 	switch (state) {
653 	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
654 		return "Active/Optimized";
655 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
656 		return "Active/NonOptimized";
657 	case ALUA_ACCESS_STATE_STANDBY:
658 		return "Standby";
659 	case ALUA_ACCESS_STATE_UNAVAILABLE:
660 		return "Unavailable";
661 	case ALUA_ACCESS_STATE_OFFLINE:
662 		return "Offline";
663 	default:
664 		return "Unknown";
665 	}
666 
667 	return NULL;
668 }
669 
670 char *core_alua_dump_status(int status)
671 {
672 	switch (status) {
673 	case ALUA_STATUS_NONE:
674 		return "None";
675 	case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
676 		return "Altered by Explict STPG";
677 	case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
678 		return "Altered by Implict ALUA";
679 	default:
680 		return "Unknown";
681 	}
682 
683 	return NULL;
684 }
685 
686 /*
687  * Used by fabric modules to determine when we need to delay processing
688  * for the Active/NonOptimized paths..
689  */
690 int core_alua_check_nonop_delay(
691 	struct se_cmd *cmd)
692 {
693 	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
694 		return 0;
695 	if (in_interrupt())
696 		return 0;
697 	/*
698 	 * The ALUA Active/NonOptimized access state delay can be disabled
699 	 * in via configfs with a value of zero
700 	 */
701 	if (!cmd->alua_nonop_delay)
702 		return 0;
703 	/*
704 	 * struct se_cmd->alua_nonop_delay gets set by a target port group
705 	 * defined interval in core_alua_state_nonoptimized()
706 	 */
707 	msleep_interruptible(cmd->alua_nonop_delay);
708 	return 0;
709 }
710 EXPORT_SYMBOL(core_alua_check_nonop_delay);
711 
712 /*
713  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
714  *
715  */
716 static int core_alua_write_tpg_metadata(
717 	const char *path,
718 	unsigned char *md_buf,
719 	u32 md_buf_len)
720 {
721 	mm_segment_t old_fs;
722 	struct file *file;
723 	struct iovec iov[1];
724 	int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
725 
726 	memset(iov, 0, sizeof(struct iovec));
727 
728 	file = filp_open(path, flags, 0600);
729 	if (IS_ERR(file) || !file || !file->f_dentry) {
730 		pr_err("filp_open(%s) for ALUA metadata failed\n",
731 			path);
732 		return -ENODEV;
733 	}
734 
735 	iov[0].iov_base = &md_buf[0];
736 	iov[0].iov_len = md_buf_len;
737 
738 	old_fs = get_fs();
739 	set_fs(get_ds());
740 	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
741 	set_fs(old_fs);
742 
743 	if (ret < 0) {
744 		pr_err("Error writing ALUA metadata file: %s\n", path);
745 		filp_close(file, NULL);
746 		return -EIO;
747 	}
748 	filp_close(file, NULL);
749 
750 	return 0;
751 }
752 
753 /*
754  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
755  */
756 static int core_alua_update_tpg_primary_metadata(
757 	struct t10_alua_tg_pt_gp *tg_pt_gp,
758 	int primary_state,
759 	unsigned char *md_buf)
760 {
761 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
762 	struct t10_wwn *wwn = &su_dev->t10_wwn;
763 	char path[ALUA_METADATA_PATH_LEN];
764 	int len;
765 
766 	memset(path, 0, ALUA_METADATA_PATH_LEN);
767 
768 	len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
769 			"tg_pt_gp_id=%hu\n"
770 			"alua_access_state=0x%02x\n"
771 			"alua_access_status=0x%02x\n",
772 			tg_pt_gp->tg_pt_gp_id, primary_state,
773 			tg_pt_gp->tg_pt_gp_alua_access_status);
774 
775 	snprintf(path, ALUA_METADATA_PATH_LEN,
776 		"/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
777 		config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
778 
779 	return core_alua_write_tpg_metadata(path, md_buf, len);
780 }
781 
782 static int core_alua_do_transition_tg_pt(
783 	struct t10_alua_tg_pt_gp *tg_pt_gp,
784 	struct se_port *l_port,
785 	struct se_node_acl *nacl,
786 	unsigned char *md_buf,
787 	int new_state,
788 	int explict)
789 {
790 	struct se_dev_entry *se_deve;
791 	struct se_lun_acl *lacl;
792 	struct se_port *port;
793 	struct t10_alua_tg_pt_gp_member *mem;
794 	int old_state = 0;
795 	/*
796 	 * Save the old primary ALUA access state, and set the current state
797 	 * to ALUA_ACCESS_STATE_TRANSITION.
798 	 */
799 	old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
800 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
801 			ALUA_ACCESS_STATE_TRANSITION);
802 	tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
803 				ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
804 				ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
805 	/*
806 	 * Check for the optional ALUA primary state transition delay
807 	 */
808 	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
809 		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
810 
811 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
812 	list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
813 				tg_pt_gp_mem_list) {
814 		port = mem->tg_pt;
815 		/*
816 		 * After an implicit target port asymmetric access state
817 		 * change, a device server shall establish a unit attention
818 		 * condition for the initiator port associated with every I_T
819 		 * nexus with the additional sense code set to ASYMMETRIC
820 		 * ACCESS STATE CHAGED.
821 		 *
822 		 * After an explicit target port asymmetric access state
823 		 * change, a device server shall establish a unit attention
824 		 * condition with the additional sense code set to ASYMMETRIC
825 		 * ACCESS STATE CHANGED for the initiator port associated with
826 		 * every I_T nexus other than the I_T nexus on which the SET
827 		 * TARGET PORT GROUPS command
828 		 */
829 		atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
830 		smp_mb__after_atomic_inc();
831 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
832 
833 		spin_lock_bh(&port->sep_alua_lock);
834 		list_for_each_entry(se_deve, &port->sep_alua_list,
835 					alua_port_list) {
836 			lacl = se_deve->se_lun_acl;
837 			/*
838 			 * se_deve->se_lun_acl pointer may be NULL for a
839 			 * entry created without explict Node+MappedLUN ACLs
840 			 */
841 			if (!lacl)
842 				continue;
843 
844 			if (explict &&
845 			   (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
846 			   (l_port != NULL) && (l_port == port))
847 				continue;
848 
849 			core_scsi3_ua_allocate(lacl->se_lun_nacl,
850 				se_deve->mapped_lun, 0x2A,
851 				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
852 		}
853 		spin_unlock_bh(&port->sep_alua_lock);
854 
855 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
856 		atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
857 		smp_mb__after_atomic_dec();
858 	}
859 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
860 	/*
861 	 * Update the ALUA metadata buf that has been allocated in
862 	 * core_alua_do_port_transition(), this metadata will be written
863 	 * to struct file.
864 	 *
865 	 * Note that there is the case where we do not want to update the
866 	 * metadata when the saved metadata is being parsed in userspace
867 	 * when setting the existing port access state and access status.
868 	 *
869 	 * Also note that the failure to write out the ALUA metadata to
870 	 * struct file does NOT affect the actual ALUA transition.
871 	 */
872 	if (tg_pt_gp->tg_pt_gp_write_metadata) {
873 		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
874 		core_alua_update_tpg_primary_metadata(tg_pt_gp,
875 					new_state, md_buf);
876 		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
877 	}
878 	/*
879 	 * Set the current primary ALUA access state to the requested new state
880 	 */
881 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
882 
883 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
884 		" from primary access state %s to %s\n", (explict) ? "explict" :
885 		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
886 		tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
887 		core_alua_dump_state(new_state));
888 
889 	return 0;
890 }
891 
892 int core_alua_do_port_transition(
893 	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
894 	struct se_device *l_dev,
895 	struct se_port *l_port,
896 	struct se_node_acl *l_nacl,
897 	int new_state,
898 	int explict)
899 {
900 	struct se_device *dev;
901 	struct se_port *port;
902 	struct se_subsystem_dev *su_dev;
903 	struct se_node_acl *nacl;
904 	struct t10_alua_lu_gp *lu_gp;
905 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
906 	struct t10_alua_tg_pt_gp *tg_pt_gp;
907 	unsigned char *md_buf;
908 	int primary;
909 
910 	if (core_alua_check_transition(new_state, &primary) != 0)
911 		return -EINVAL;
912 
913 	md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
914 	if (!md_buf) {
915 		pr_err("Unable to allocate buf for ALUA metadata\n");
916 		return -ENOMEM;
917 	}
918 
919 	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
920 	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
921 	lu_gp = local_lu_gp_mem->lu_gp;
922 	atomic_inc(&lu_gp->lu_gp_ref_cnt);
923 	smp_mb__after_atomic_inc();
924 	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
925 	/*
926 	 * For storage objects that are members of the 'default_lu_gp',
927 	 * we only do transition on the passed *l_tp_pt_gp, and not
928 	 * on all of the matching target port groups IDs in default_lu_gp.
929 	 */
930 	if (!lu_gp->lu_gp_id) {
931 		/*
932 		 * core_alua_do_transition_tg_pt() will always return
933 		 * success.
934 		 */
935 		core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
936 					md_buf, new_state, explict);
937 		atomic_dec(&lu_gp->lu_gp_ref_cnt);
938 		smp_mb__after_atomic_dec();
939 		kfree(md_buf);
940 		return 0;
941 	}
942 	/*
943 	 * For all other LU groups aside from 'default_lu_gp', walk all of
944 	 * the associated storage objects looking for a matching target port
945 	 * group ID from the local target port group.
946 	 */
947 	spin_lock(&lu_gp->lu_gp_lock);
948 	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
949 				lu_gp_mem_list) {
950 
951 		dev = lu_gp_mem->lu_gp_mem_dev;
952 		su_dev = dev->se_sub_dev;
953 		atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
954 		smp_mb__after_atomic_inc();
955 		spin_unlock(&lu_gp->lu_gp_lock);
956 
957 		spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
958 		list_for_each_entry(tg_pt_gp,
959 				&su_dev->t10_alua.tg_pt_gps_list,
960 				tg_pt_gp_list) {
961 
962 			if (!tg_pt_gp->tg_pt_gp_valid_id)
963 				continue;
964 			/*
965 			 * If the target behavior port asymmetric access state
966 			 * is changed for any target port group accessiable via
967 			 * a logical unit within a LU group, the target port
968 			 * behavior group asymmetric access states for the same
969 			 * target port group accessible via other logical units
970 			 * in that LU group will also change.
971 			 */
972 			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
973 				continue;
974 
975 			if (l_tg_pt_gp == tg_pt_gp) {
976 				port = l_port;
977 				nacl = l_nacl;
978 			} else {
979 				port = NULL;
980 				nacl = NULL;
981 			}
982 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
983 			smp_mb__after_atomic_inc();
984 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
985 			/*
986 			 * core_alua_do_transition_tg_pt() will always return
987 			 * success.
988 			 */
989 			core_alua_do_transition_tg_pt(tg_pt_gp, port,
990 					nacl, md_buf, new_state, explict);
991 
992 			spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
993 			atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
994 			smp_mb__after_atomic_dec();
995 		}
996 		spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
997 
998 		spin_lock(&lu_gp->lu_gp_lock);
999 		atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
1000 		smp_mb__after_atomic_dec();
1001 	}
1002 	spin_unlock(&lu_gp->lu_gp_lock);
1003 
1004 	pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1005 		" Group IDs: %hu %s transition to primary state: %s\n",
1006 		config_item_name(&lu_gp->lu_gp_group.cg_item),
1007 		l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
1008 		core_alua_dump_state(new_state));
1009 
1010 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1011 	smp_mb__after_atomic_dec();
1012 	kfree(md_buf);
1013 	return 0;
1014 }
1015 
1016 /*
1017  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
1018  */
1019 static int core_alua_update_tpg_secondary_metadata(
1020 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1021 	struct se_port *port,
1022 	unsigned char *md_buf,
1023 	u32 md_buf_len)
1024 {
1025 	struct se_portal_group *se_tpg = port->sep_tpg;
1026 	char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
1027 	int len;
1028 
1029 	memset(path, 0, ALUA_METADATA_PATH_LEN);
1030 	memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
1031 
1032 	len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
1033 			se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
1034 
1035 	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1036 		snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1037 				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1038 
1039 	len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1040 			"alua_tg_pt_status=0x%02x\n",
1041 			atomic_read(&port->sep_tg_pt_secondary_offline),
1042 			port->sep_tg_pt_secondary_stat);
1043 
1044 	snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1045 			se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1046 			port->sep_lun->unpacked_lun);
1047 
1048 	return core_alua_write_tpg_metadata(path, md_buf, len);
1049 }
1050 
1051 static int core_alua_set_tg_pt_secondary_state(
1052 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1053 	struct se_port *port,
1054 	int explict,
1055 	int offline)
1056 {
1057 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1058 	unsigned char *md_buf;
1059 	u32 md_buf_len;
1060 	int trans_delay_msecs;
1061 
1062 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1063 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1064 	if (!tg_pt_gp) {
1065 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1066 		pr_err("Unable to complete secondary state"
1067 				" transition\n");
1068 		return -EINVAL;
1069 	}
1070 	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1071 	/*
1072 	 * Set the secondary ALUA target port access state to OFFLINE
1073 	 * or release the previously secondary state for struct se_port
1074 	 */
1075 	if (offline)
1076 		atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1077 	else
1078 		atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1079 
1080 	md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1081 	port->sep_tg_pt_secondary_stat = (explict) ?
1082 			ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1083 			ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1084 
1085 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1086 		" to secondary access state: %s\n", (explict) ? "explict" :
1087 		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1088 		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1089 
1090 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1091 	/*
1092 	 * Do the optional transition delay after we set the secondary
1093 	 * ALUA access state.
1094 	 */
1095 	if (trans_delay_msecs != 0)
1096 		msleep_interruptible(trans_delay_msecs);
1097 	/*
1098 	 * See if we need to update the ALUA fabric port metadata for
1099 	 * secondary state and status
1100 	 */
1101 	if (port->sep_tg_pt_secondary_write_md) {
1102 		md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1103 		if (!md_buf) {
1104 			pr_err("Unable to allocate md_buf for"
1105 				" secondary ALUA access metadata\n");
1106 			return -ENOMEM;
1107 		}
1108 		mutex_lock(&port->sep_tg_pt_md_mutex);
1109 		core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1110 				md_buf, md_buf_len);
1111 		mutex_unlock(&port->sep_tg_pt_md_mutex);
1112 
1113 		kfree(md_buf);
1114 	}
1115 
1116 	return 0;
1117 }
1118 
1119 struct t10_alua_lu_gp *
1120 core_alua_allocate_lu_gp(const char *name, int def_group)
1121 {
1122 	struct t10_alua_lu_gp *lu_gp;
1123 
1124 	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1125 	if (!lu_gp) {
1126 		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1127 		return ERR_PTR(-ENOMEM);
1128 	}
1129 	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1130 	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1131 	spin_lock_init(&lu_gp->lu_gp_lock);
1132 	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1133 
1134 	if (def_group) {
1135 		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1136 		lu_gp->lu_gp_valid_id = 1;
1137 		alua_lu_gps_count++;
1138 	}
1139 
1140 	return lu_gp;
1141 }
1142 
1143 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1144 {
1145 	struct t10_alua_lu_gp *lu_gp_tmp;
1146 	u16 lu_gp_id_tmp;
1147 	/*
1148 	 * The lu_gp->lu_gp_id may only be set once..
1149 	 */
1150 	if (lu_gp->lu_gp_valid_id) {
1151 		pr_warn("ALUA LU Group already has a valid ID,"
1152 			" ignoring request\n");
1153 		return -EINVAL;
1154 	}
1155 
1156 	spin_lock(&lu_gps_lock);
1157 	if (alua_lu_gps_count == 0x0000ffff) {
1158 		pr_err("Maximum ALUA alua_lu_gps_count:"
1159 				" 0x0000ffff reached\n");
1160 		spin_unlock(&lu_gps_lock);
1161 		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1162 		return -ENOSPC;
1163 	}
1164 again:
1165 	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1166 				alua_lu_gps_counter++;
1167 
1168 	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1169 		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1170 			if (!lu_gp_id)
1171 				goto again;
1172 
1173 			pr_warn("ALUA Logical Unit Group ID: %hu"
1174 				" already exists, ignoring request\n",
1175 				lu_gp_id);
1176 			spin_unlock(&lu_gps_lock);
1177 			return -EINVAL;
1178 		}
1179 	}
1180 
1181 	lu_gp->lu_gp_id = lu_gp_id_tmp;
1182 	lu_gp->lu_gp_valid_id = 1;
1183 	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1184 	alua_lu_gps_count++;
1185 	spin_unlock(&lu_gps_lock);
1186 
1187 	return 0;
1188 }
1189 
1190 static struct t10_alua_lu_gp_member *
1191 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1192 {
1193 	struct t10_alua_lu_gp_member *lu_gp_mem;
1194 
1195 	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1196 	if (!lu_gp_mem) {
1197 		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1198 		return ERR_PTR(-ENOMEM);
1199 	}
1200 	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1201 	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1202 	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1203 
1204 	lu_gp_mem->lu_gp_mem_dev = dev;
1205 	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1206 
1207 	return lu_gp_mem;
1208 }
1209 
1210 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1211 {
1212 	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1213 	/*
1214 	 * Once we have reached this point, config_item_put() has
1215 	 * already been called from target_core_alua_drop_lu_gp().
1216 	 *
1217 	 * Here, we remove the *lu_gp from the global list so that
1218 	 * no associations can be made while we are releasing
1219 	 * struct t10_alua_lu_gp.
1220 	 */
1221 	spin_lock(&lu_gps_lock);
1222 	list_del(&lu_gp->lu_gp_node);
1223 	alua_lu_gps_count--;
1224 	spin_unlock(&lu_gps_lock);
1225 	/*
1226 	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1227 	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1228 	 * released with core_alua_put_lu_gp_from_name()
1229 	 */
1230 	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1231 		cpu_relax();
1232 	/*
1233 	 * Release reference to struct t10_alua_lu_gp * from all associated
1234 	 * struct se_device.
1235 	 */
1236 	spin_lock(&lu_gp->lu_gp_lock);
1237 	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1238 				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1239 		if (lu_gp_mem->lu_gp_assoc) {
1240 			list_del(&lu_gp_mem->lu_gp_mem_list);
1241 			lu_gp->lu_gp_members--;
1242 			lu_gp_mem->lu_gp_assoc = 0;
1243 		}
1244 		spin_unlock(&lu_gp->lu_gp_lock);
1245 		/*
1246 		 *
1247 		 * lu_gp_mem is associated with a single
1248 		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1249 		 * struct se_device is released via core_alua_free_lu_gp_mem().
1250 		 *
1251 		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1252 		 * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1253 		 */
1254 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1255 		if (lu_gp != default_lu_gp)
1256 			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1257 					default_lu_gp);
1258 		else
1259 			lu_gp_mem->lu_gp = NULL;
1260 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1261 
1262 		spin_lock(&lu_gp->lu_gp_lock);
1263 	}
1264 	spin_unlock(&lu_gp->lu_gp_lock);
1265 
1266 	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1267 }
1268 
1269 void core_alua_free_lu_gp_mem(struct se_device *dev)
1270 {
1271 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1272 	struct t10_alua *alua = &su_dev->t10_alua;
1273 	struct t10_alua_lu_gp *lu_gp;
1274 	struct t10_alua_lu_gp_member *lu_gp_mem;
1275 
1276 	if (alua->alua_type != SPC3_ALUA_EMULATED)
1277 		return;
1278 
1279 	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1280 	if (!lu_gp_mem)
1281 		return;
1282 
1283 	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1284 		cpu_relax();
1285 
1286 	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1287 	lu_gp = lu_gp_mem->lu_gp;
1288 	if (lu_gp) {
1289 		spin_lock(&lu_gp->lu_gp_lock);
1290 		if (lu_gp_mem->lu_gp_assoc) {
1291 			list_del(&lu_gp_mem->lu_gp_mem_list);
1292 			lu_gp->lu_gp_members--;
1293 			lu_gp_mem->lu_gp_assoc = 0;
1294 		}
1295 		spin_unlock(&lu_gp->lu_gp_lock);
1296 		lu_gp_mem->lu_gp = NULL;
1297 	}
1298 	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1299 
1300 	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1301 }
1302 
1303 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1304 {
1305 	struct t10_alua_lu_gp *lu_gp;
1306 	struct config_item *ci;
1307 
1308 	spin_lock(&lu_gps_lock);
1309 	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1310 		if (!lu_gp->lu_gp_valid_id)
1311 			continue;
1312 		ci = &lu_gp->lu_gp_group.cg_item;
1313 		if (!strcmp(config_item_name(ci), name)) {
1314 			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1315 			spin_unlock(&lu_gps_lock);
1316 			return lu_gp;
1317 		}
1318 	}
1319 	spin_unlock(&lu_gps_lock);
1320 
1321 	return NULL;
1322 }
1323 
1324 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1325 {
1326 	spin_lock(&lu_gps_lock);
1327 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1328 	spin_unlock(&lu_gps_lock);
1329 }
1330 
1331 /*
1332  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1333  */
1334 void __core_alua_attach_lu_gp_mem(
1335 	struct t10_alua_lu_gp_member *lu_gp_mem,
1336 	struct t10_alua_lu_gp *lu_gp)
1337 {
1338 	spin_lock(&lu_gp->lu_gp_lock);
1339 	lu_gp_mem->lu_gp = lu_gp;
1340 	lu_gp_mem->lu_gp_assoc = 1;
1341 	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1342 	lu_gp->lu_gp_members++;
1343 	spin_unlock(&lu_gp->lu_gp_lock);
1344 }
1345 
1346 /*
1347  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1348  */
1349 void __core_alua_drop_lu_gp_mem(
1350 	struct t10_alua_lu_gp_member *lu_gp_mem,
1351 	struct t10_alua_lu_gp *lu_gp)
1352 {
1353 	spin_lock(&lu_gp->lu_gp_lock);
1354 	list_del(&lu_gp_mem->lu_gp_mem_list);
1355 	lu_gp_mem->lu_gp = NULL;
1356 	lu_gp_mem->lu_gp_assoc = 0;
1357 	lu_gp->lu_gp_members--;
1358 	spin_unlock(&lu_gp->lu_gp_lock);
1359 }
1360 
1361 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1362 	struct se_subsystem_dev *su_dev,
1363 	const char *name,
1364 	int def_group)
1365 {
1366 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1367 
1368 	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1369 	if (!tg_pt_gp) {
1370 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1371 		return NULL;
1372 	}
1373 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1374 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1375 	mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1376 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1377 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1378 	tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1379 	tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1380 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1381 		ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1382 	/*
1383 	 * Enable both explict and implict ALUA support by default
1384 	 */
1385 	tg_pt_gp->tg_pt_gp_alua_access_type =
1386 			TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1387 	/*
1388 	 * Set the default Active/NonOptimized Delay in milliseconds
1389 	 */
1390 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1391 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1392 	tg_pt_gp->tg_pt_gp_implict_trans_secs = ALUA_DEFAULT_IMPLICT_TRANS_SECS;
1393 
1394 	if (def_group) {
1395 		spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1396 		tg_pt_gp->tg_pt_gp_id =
1397 				su_dev->t10_alua.alua_tg_pt_gps_counter++;
1398 		tg_pt_gp->tg_pt_gp_valid_id = 1;
1399 		su_dev->t10_alua.alua_tg_pt_gps_count++;
1400 		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1401 			      &su_dev->t10_alua.tg_pt_gps_list);
1402 		spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1403 	}
1404 
1405 	return tg_pt_gp;
1406 }
1407 
1408 int core_alua_set_tg_pt_gp_id(
1409 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1410 	u16 tg_pt_gp_id)
1411 {
1412 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1413 	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1414 	u16 tg_pt_gp_id_tmp;
1415 	/*
1416 	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1417 	 */
1418 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1419 		pr_warn("ALUA TG PT Group already has a valid ID,"
1420 			" ignoring request\n");
1421 		return -EINVAL;
1422 	}
1423 
1424 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1425 	if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1426 		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1427 			" 0x0000ffff reached\n");
1428 		spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1429 		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1430 		return -ENOSPC;
1431 	}
1432 again:
1433 	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1434 			su_dev->t10_alua.alua_tg_pt_gps_counter++;
1435 
1436 	list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1437 			tg_pt_gp_list) {
1438 		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1439 			if (!tg_pt_gp_id)
1440 				goto again;
1441 
1442 			pr_err("ALUA Target Port Group ID: %hu already"
1443 				" exists, ignoring request\n", tg_pt_gp_id);
1444 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1445 			return -EINVAL;
1446 		}
1447 	}
1448 
1449 	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1450 	tg_pt_gp->tg_pt_gp_valid_id = 1;
1451 	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1452 			&su_dev->t10_alua.tg_pt_gps_list);
1453 	su_dev->t10_alua.alua_tg_pt_gps_count++;
1454 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1455 
1456 	return 0;
1457 }
1458 
1459 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1460 	struct se_port *port)
1461 {
1462 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1463 
1464 	tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1465 				GFP_KERNEL);
1466 	if (!tg_pt_gp_mem) {
1467 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1468 		return ERR_PTR(-ENOMEM);
1469 	}
1470 	INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1471 	spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1472 	atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1473 
1474 	tg_pt_gp_mem->tg_pt = port;
1475 	port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1476 
1477 	return tg_pt_gp_mem;
1478 }
1479 
1480 void core_alua_free_tg_pt_gp(
1481 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1482 {
1483 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1484 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1485 	/*
1486 	 * Once we have reached this point, config_item_put() has already
1487 	 * been called from target_core_alua_drop_tg_pt_gp().
1488 	 *
1489 	 * Here we remove *tg_pt_gp from the global list so that
1490 	 * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1491 	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1492 	 */
1493 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1494 	list_del(&tg_pt_gp->tg_pt_gp_list);
1495 	su_dev->t10_alua.alua_tg_pt_gps_counter--;
1496 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1497 	/*
1498 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1499 	 * core_alua_get_tg_pt_gp_by_name() in
1500 	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1501 	 * to be released with core_alua_put_tg_pt_gp_from_name().
1502 	 */
1503 	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1504 		cpu_relax();
1505 	/*
1506 	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1507 	 * struct se_port.
1508 	 */
1509 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1510 	list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1511 			&tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1512 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1513 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1514 			tg_pt_gp->tg_pt_gp_members--;
1515 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1516 		}
1517 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1518 		/*
1519 		 * tg_pt_gp_mem is associated with a single
1520 		 * se_port->sep_alua_tg_pt_gp_mem, and is released via
1521 		 * core_alua_free_tg_pt_gp_mem().
1522 		 *
1523 		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1524 		 * assume we want to re-assocate a given tg_pt_gp_mem with
1525 		 * default_tg_pt_gp.
1526 		 */
1527 		spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1528 		if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1529 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1530 					su_dev->t10_alua.default_tg_pt_gp);
1531 		} else
1532 			tg_pt_gp_mem->tg_pt_gp = NULL;
1533 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1534 
1535 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1536 	}
1537 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1538 
1539 	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1540 }
1541 
1542 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1543 {
1544 	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1545 	struct t10_alua *alua = &su_dev->t10_alua;
1546 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1547 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1548 
1549 	if (alua->alua_type != SPC3_ALUA_EMULATED)
1550 		return;
1551 
1552 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1553 	if (!tg_pt_gp_mem)
1554 		return;
1555 
1556 	while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1557 		cpu_relax();
1558 
1559 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1560 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1561 	if (tg_pt_gp) {
1562 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1563 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1564 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1565 			tg_pt_gp->tg_pt_gp_members--;
1566 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1567 		}
1568 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1569 		tg_pt_gp_mem->tg_pt_gp = NULL;
1570 	}
1571 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1572 
1573 	kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1574 }
1575 
1576 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1577 	struct se_subsystem_dev *su_dev,
1578 	const char *name)
1579 {
1580 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1581 	struct config_item *ci;
1582 
1583 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1584 	list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1585 			tg_pt_gp_list) {
1586 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1587 			continue;
1588 		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1589 		if (!strcmp(config_item_name(ci), name)) {
1590 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1591 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1592 			return tg_pt_gp;
1593 		}
1594 	}
1595 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1596 
1597 	return NULL;
1598 }
1599 
1600 static void core_alua_put_tg_pt_gp_from_name(
1601 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1602 {
1603 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1604 
1605 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1606 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1607 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1608 }
1609 
1610 /*
1611  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1612  */
1613 void __core_alua_attach_tg_pt_gp_mem(
1614 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1615 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1616 {
1617 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1618 	tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1619 	tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1620 	list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1621 			&tg_pt_gp->tg_pt_gp_mem_list);
1622 	tg_pt_gp->tg_pt_gp_members++;
1623 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1624 }
1625 
1626 /*
1627  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1628  */
1629 static void __core_alua_drop_tg_pt_gp_mem(
1630 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1631 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1632 {
1633 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1634 	list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1635 	tg_pt_gp_mem->tg_pt_gp = NULL;
1636 	tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1637 	tg_pt_gp->tg_pt_gp_members--;
1638 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1639 }
1640 
1641 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1642 {
1643 	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1644 	struct config_item *tg_pt_ci;
1645 	struct t10_alua *alua = &su_dev->t10_alua;
1646 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1647 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1648 	ssize_t len = 0;
1649 
1650 	if (alua->alua_type != SPC3_ALUA_EMULATED)
1651 		return len;
1652 
1653 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1654 	if (!tg_pt_gp_mem)
1655 		return len;
1656 
1657 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1658 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1659 	if (tg_pt_gp) {
1660 		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1661 		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1662 			" %hu\nTG Port Primary Access State: %s\nTG Port "
1663 			"Primary Access Status: %s\nTG Port Secondary Access"
1664 			" State: %s\nTG Port Secondary Access Status: %s\n",
1665 			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1666 			core_alua_dump_state(atomic_read(
1667 					&tg_pt_gp->tg_pt_gp_alua_access_state)),
1668 			core_alua_dump_status(
1669 				tg_pt_gp->tg_pt_gp_alua_access_status),
1670 			(atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1671 			"Offline" : "None",
1672 			core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1673 	}
1674 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1675 
1676 	return len;
1677 }
1678 
1679 ssize_t core_alua_store_tg_pt_gp_info(
1680 	struct se_port *port,
1681 	const char *page,
1682 	size_t count)
1683 {
1684 	struct se_portal_group *tpg;
1685 	struct se_lun *lun;
1686 	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1687 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1688 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1689 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1690 	int move = 0;
1691 
1692 	tpg = port->sep_tpg;
1693 	lun = port->sep_lun;
1694 
1695 	if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1696 		pr_warn("SPC3_ALUA_EMULATED not enabled for"
1697 			" %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1698 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1699 			config_item_name(&lun->lun_group.cg_item));
1700 		return -EINVAL;
1701 	}
1702 
1703 	if (count > TG_PT_GROUP_NAME_BUF) {
1704 		pr_err("ALUA Target Port Group alias too large!\n");
1705 		return -EINVAL;
1706 	}
1707 	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1708 	memcpy(buf, page, count);
1709 	/*
1710 	 * Any ALUA target port group alias besides "NULL" means we will be
1711 	 * making a new group association.
1712 	 */
1713 	if (strcmp(strstrip(buf), "NULL")) {
1714 		/*
1715 		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1716 		 * struct t10_alua_tg_pt_gp.  This reference is released with
1717 		 * core_alua_put_tg_pt_gp_from_name() below.
1718 		 */
1719 		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1720 					strstrip(buf));
1721 		if (!tg_pt_gp_new)
1722 			return -ENODEV;
1723 	}
1724 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1725 	if (!tg_pt_gp_mem) {
1726 		if (tg_pt_gp_new)
1727 			core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1728 		pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1729 		return -EINVAL;
1730 	}
1731 
1732 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1733 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1734 	if (tg_pt_gp) {
1735 		/*
1736 		 * Clearing an existing tg_pt_gp association, and replacing
1737 		 * with the default_tg_pt_gp.
1738 		 */
1739 		if (!tg_pt_gp_new) {
1740 			pr_debug("Target_Core_ConfigFS: Moving"
1741 				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
1742 				" alua/%s, ID: %hu back to"
1743 				" default_tg_pt_gp\n",
1744 				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1745 				tpg->se_tpg_tfo->tpg_get_tag(tpg),
1746 				config_item_name(&lun->lun_group.cg_item),
1747 				config_item_name(
1748 					&tg_pt_gp->tg_pt_gp_group.cg_item),
1749 				tg_pt_gp->tg_pt_gp_id);
1750 
1751 			__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1752 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1753 					su_dev->t10_alua.default_tg_pt_gp);
1754 			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1755 
1756 			return count;
1757 		}
1758 		/*
1759 		 * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1760 		 */
1761 		__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1762 		move = 1;
1763 	}
1764 	/*
1765 	 * Associate tg_pt_gp_mem with tg_pt_gp_new.
1766 	 */
1767 	__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1768 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1769 	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1770 		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
1771 		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1772 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
1773 		config_item_name(&lun->lun_group.cg_item),
1774 		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1775 		tg_pt_gp_new->tg_pt_gp_id);
1776 
1777 	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1778 	return count;
1779 }
1780 
1781 ssize_t core_alua_show_access_type(
1782 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1783 	char *page)
1784 {
1785 	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1786 	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1787 		return sprintf(page, "Implict and Explict\n");
1788 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1789 		return sprintf(page, "Implict\n");
1790 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1791 		return sprintf(page, "Explict\n");
1792 	else
1793 		return sprintf(page, "None\n");
1794 }
1795 
1796 ssize_t core_alua_store_access_type(
1797 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1798 	const char *page,
1799 	size_t count)
1800 {
1801 	unsigned long tmp;
1802 	int ret;
1803 
1804 	ret = strict_strtoul(page, 0, &tmp);
1805 	if (ret < 0) {
1806 		pr_err("Unable to extract alua_access_type\n");
1807 		return -EINVAL;
1808 	}
1809 	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1810 		pr_err("Illegal value for alua_access_type:"
1811 				" %lu\n", tmp);
1812 		return -EINVAL;
1813 	}
1814 	if (tmp == 3)
1815 		tg_pt_gp->tg_pt_gp_alua_access_type =
1816 			TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1817 	else if (tmp == 2)
1818 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1819 	else if (tmp == 1)
1820 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1821 	else
1822 		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1823 
1824 	return count;
1825 }
1826 
1827 ssize_t core_alua_show_nonop_delay_msecs(
1828 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1829 	char *page)
1830 {
1831 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1832 }
1833 
1834 ssize_t core_alua_store_nonop_delay_msecs(
1835 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1836 	const char *page,
1837 	size_t count)
1838 {
1839 	unsigned long tmp;
1840 	int ret;
1841 
1842 	ret = strict_strtoul(page, 0, &tmp);
1843 	if (ret < 0) {
1844 		pr_err("Unable to extract nonop_delay_msecs\n");
1845 		return -EINVAL;
1846 	}
1847 	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1848 		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1849 			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1850 			ALUA_MAX_NONOP_DELAY_MSECS);
1851 		return -EINVAL;
1852 	}
1853 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1854 
1855 	return count;
1856 }
1857 
1858 ssize_t core_alua_show_trans_delay_msecs(
1859 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1860 	char *page)
1861 {
1862 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1863 }
1864 
1865 ssize_t core_alua_store_trans_delay_msecs(
1866 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1867 	const char *page,
1868 	size_t count)
1869 {
1870 	unsigned long tmp;
1871 	int ret;
1872 
1873 	ret = strict_strtoul(page, 0, &tmp);
1874 	if (ret < 0) {
1875 		pr_err("Unable to extract trans_delay_msecs\n");
1876 		return -EINVAL;
1877 	}
1878 	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1879 		pr_err("Passed trans_delay_msecs: %lu, exceeds"
1880 			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1881 			ALUA_MAX_TRANS_DELAY_MSECS);
1882 		return -EINVAL;
1883 	}
1884 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1885 
1886 	return count;
1887 }
1888 
1889 ssize_t core_alua_show_implict_trans_secs(
1890 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1891 	char *page)
1892 {
1893 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implict_trans_secs);
1894 }
1895 
1896 ssize_t core_alua_store_implict_trans_secs(
1897 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1898 	const char *page,
1899 	size_t count)
1900 {
1901 	unsigned long tmp;
1902 	int ret;
1903 
1904 	ret = strict_strtoul(page, 0, &tmp);
1905 	if (ret < 0) {
1906 		pr_err("Unable to extract implict_trans_secs\n");
1907 		return -EINVAL;
1908 	}
1909 	if (tmp > ALUA_MAX_IMPLICT_TRANS_SECS) {
1910 		pr_err("Passed implict_trans_secs: %lu, exceeds"
1911 			" ALUA_MAX_IMPLICT_TRANS_SECS: %d\n", tmp,
1912 			ALUA_MAX_IMPLICT_TRANS_SECS);
1913 		return  -EINVAL;
1914 	}
1915 	tg_pt_gp->tg_pt_gp_implict_trans_secs = (int)tmp;
1916 
1917 	return count;
1918 }
1919 
1920 ssize_t core_alua_show_preferred_bit(
1921 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1922 	char *page)
1923 {
1924 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1925 }
1926 
1927 ssize_t core_alua_store_preferred_bit(
1928 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1929 	const char *page,
1930 	size_t count)
1931 {
1932 	unsigned long tmp;
1933 	int ret;
1934 
1935 	ret = strict_strtoul(page, 0, &tmp);
1936 	if (ret < 0) {
1937 		pr_err("Unable to extract preferred ALUA value\n");
1938 		return -EINVAL;
1939 	}
1940 	if ((tmp != 0) && (tmp != 1)) {
1941 		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1942 		return -EINVAL;
1943 	}
1944 	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1945 
1946 	return count;
1947 }
1948 
1949 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1950 {
1951 	if (!lun->lun_sep)
1952 		return -ENODEV;
1953 
1954 	return sprintf(page, "%d\n",
1955 		atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1956 }
1957 
1958 ssize_t core_alua_store_offline_bit(
1959 	struct se_lun *lun,
1960 	const char *page,
1961 	size_t count)
1962 {
1963 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1964 	unsigned long tmp;
1965 	int ret;
1966 
1967 	if (!lun->lun_sep)
1968 		return -ENODEV;
1969 
1970 	ret = strict_strtoul(page, 0, &tmp);
1971 	if (ret < 0) {
1972 		pr_err("Unable to extract alua_tg_pt_offline value\n");
1973 		return -EINVAL;
1974 	}
1975 	if ((tmp != 0) && (tmp != 1)) {
1976 		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1977 				tmp);
1978 		return -EINVAL;
1979 	}
1980 	tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1981 	if (!tg_pt_gp_mem) {
1982 		pr_err("Unable to locate *tg_pt_gp_mem\n");
1983 		return -EINVAL;
1984 	}
1985 
1986 	ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1987 			lun->lun_sep, 0, (int)tmp);
1988 	if (ret < 0)
1989 		return -EINVAL;
1990 
1991 	return count;
1992 }
1993 
1994 ssize_t core_alua_show_secondary_status(
1995 	struct se_lun *lun,
1996 	char *page)
1997 {
1998 	return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1999 }
2000 
2001 ssize_t core_alua_store_secondary_status(
2002 	struct se_lun *lun,
2003 	const char *page,
2004 	size_t count)
2005 {
2006 	unsigned long tmp;
2007 	int ret;
2008 
2009 	ret = strict_strtoul(page, 0, &tmp);
2010 	if (ret < 0) {
2011 		pr_err("Unable to extract alua_tg_pt_status\n");
2012 		return -EINVAL;
2013 	}
2014 	if ((tmp != ALUA_STATUS_NONE) &&
2015 	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
2016 	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
2017 		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2018 				tmp);
2019 		return -EINVAL;
2020 	}
2021 	lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
2022 
2023 	return count;
2024 }
2025 
2026 ssize_t core_alua_show_secondary_write_metadata(
2027 	struct se_lun *lun,
2028 	char *page)
2029 {
2030 	return sprintf(page, "%d\n",
2031 			lun->lun_sep->sep_tg_pt_secondary_write_md);
2032 }
2033 
2034 ssize_t core_alua_store_secondary_write_metadata(
2035 	struct se_lun *lun,
2036 	const char *page,
2037 	size_t count)
2038 {
2039 	unsigned long tmp;
2040 	int ret;
2041 
2042 	ret = strict_strtoul(page, 0, &tmp);
2043 	if (ret < 0) {
2044 		pr_err("Unable to extract alua_tg_pt_write_md\n");
2045 		return -EINVAL;
2046 	}
2047 	if ((tmp != 0) && (tmp != 1)) {
2048 		pr_err("Illegal value for alua_tg_pt_write_md:"
2049 				" %lu\n", tmp);
2050 		return -EINVAL;
2051 	}
2052 	lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
2053 
2054 	return count;
2055 }
2056 
2057 int core_setup_alua(struct se_device *dev, int force_pt)
2058 {
2059 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
2060 	struct t10_alua *alua = &su_dev->t10_alua;
2061 	struct t10_alua_lu_gp_member *lu_gp_mem;
2062 	/*
2063 	 * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
2064 	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2065 	 * cause a problem because libata and some SATA RAID HBAs appear
2066 	 * under Linux/SCSI, but emulate SCSI logic themselves.
2067 	 */
2068 	if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2069 	    !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2070 		alua->alua_type = SPC_ALUA_PASSTHROUGH;
2071 		alua->alua_state_check = &core_alua_state_check_nop;
2072 		pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2073 			" emulation\n", dev->transport->name);
2074 		return 0;
2075 	}
2076 	/*
2077 	 * If SPC-3 or above is reported by real or emulated struct se_device,
2078 	 * use emulated ALUA.
2079 	 */
2080 	if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2081 		pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2082 			" device\n", dev->transport->name);
2083 		/*
2084 		 * Associate this struct se_device with the default ALUA
2085 		 * LUN Group.
2086 		 */
2087 		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2088 		if (IS_ERR(lu_gp_mem))
2089 			return PTR_ERR(lu_gp_mem);
2090 
2091 		alua->alua_type = SPC3_ALUA_EMULATED;
2092 		alua->alua_state_check = &core_alua_state_check;
2093 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2094 		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2095 				default_lu_gp);
2096 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2097 
2098 		pr_debug("%s: Adding to default ALUA LU Group:"
2099 			" core/alua/lu_gps/default_lu_gp\n",
2100 			dev->transport->name);
2101 	} else {
2102 		alua->alua_type = SPC2_ALUA_DISABLED;
2103 		alua->alua_state_check = &core_alua_state_check_nop;
2104 		pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2105 			" device\n", dev->transport->name);
2106 	}
2107 
2108 	return 0;
2109 }
2110