xref: /linux/drivers/target/target_core_alua.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
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 
34 #include <target/target_core_base.h>
35 #include <target/target_core_device.h>
36 #include <target/target_core_transport.h>
37 #include <target/target_core_fabric_ops.h>
38 #include <target/target_core_configfs.h>
39 
40 #include "target_core_alua.h"
41 #include "target_core_hba.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_task *task)
63 {
64 	struct se_cmd *cmd = task->task_se_cmd;
65 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
66 	struct se_port *port;
67 	struct t10_alua_tg_pt_gp *tg_pt_gp;
68 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
69 	unsigned char *buf;
70 	u32 rd_len = 0, off = 4; /* Skip over RESERVED area to first
71 				    Target port group descriptor */
72 	/*
73 	 * Need at least 4 bytes of response data or else we can't
74 	 * even fit the return data length.
75 	 */
76 	if (cmd->data_length < 4) {
77 		pr_warn("REPORT TARGET PORT GROUPS allocation length %u"
78 			" too small\n", cmd->data_length);
79 		return -EINVAL;
80 	}
81 
82 	buf = transport_kmap_first_data_page(cmd);
83 
84 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
85 	list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
86 			tg_pt_gp_list) {
87 		/*
88 		 * Check if the Target port group and Target port descriptor list
89 		 * based on tg_pt_gp_members count will fit into the response payload.
90 		 * Otherwise, bump rd_len to let the initiator know we have exceeded
91 		 * the allocation length and the response is truncated.
92 		 */
93 		if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
94 		     cmd->data_length) {
95 			rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
96 			continue;
97 		}
98 		/*
99 		 * PREF: Preferred target port bit, determine if this
100 		 * bit should be set for port group.
101 		 */
102 		if (tg_pt_gp->tg_pt_gp_pref)
103 			buf[off] = 0x80;
104 		/*
105 		 * Set the ASYMMETRIC ACCESS State
106 		 */
107 		buf[off++] |= (atomic_read(
108 			&tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
109 		/*
110 		 * Set supported ASYMMETRIC ACCESS State bits
111 		 */
112 		buf[off] = 0x80; /* T_SUP */
113 		buf[off] |= 0x40; /* O_SUP */
114 		buf[off] |= 0x8; /* U_SUP */
115 		buf[off] |= 0x4; /* S_SUP */
116 		buf[off] |= 0x2; /* AN_SUP */
117 		buf[off++] |= 0x1; /* AO_SUP */
118 		/*
119 		 * TARGET PORT GROUP
120 		 */
121 		buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
122 		buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
123 
124 		off++; /* Skip over Reserved */
125 		/*
126 		 * STATUS CODE
127 		 */
128 		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
129 		/*
130 		 * Vendor Specific field
131 		 */
132 		buf[off++] = 0x00;
133 		/*
134 		 * TARGET PORT COUNT
135 		 */
136 		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
137 		rd_len += 8;
138 
139 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
140 		list_for_each_entry(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
141 				tg_pt_gp_mem_list) {
142 			port = tg_pt_gp_mem->tg_pt;
143 			/*
144 			 * Start Target Port descriptor format
145 			 *
146 			 * See spc4r17 section 6.2.7 Table 247
147 			 */
148 			off += 2; /* Skip over Obsolete */
149 			/*
150 			 * Set RELATIVE TARGET PORT IDENTIFIER
151 			 */
152 			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
153 			buf[off++] = (port->sep_rtpi & 0xff);
154 			rd_len += 4;
155 		}
156 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
157 	}
158 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
159 	/*
160 	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
161 	 */
162 	buf[0] = ((rd_len >> 24) & 0xff);
163 	buf[1] = ((rd_len >> 16) & 0xff);
164 	buf[2] = ((rd_len >> 8) & 0xff);
165 	buf[3] = (rd_len & 0xff);
166 
167 	transport_kunmap_first_data_page(cmd);
168 
169 	task->task_scsi_status = GOOD;
170 	transport_complete_task(task, 1);
171 	return 0;
172 }
173 
174 /*
175  * SET_TARGET_PORT_GROUPS for explict ALUA operation.
176  *
177  * See spc4r17 section 6.35
178  */
179 int target_emulate_set_target_port_groups(struct se_task *task)
180 {
181 	struct se_cmd *cmd = task->task_se_cmd;
182 	struct se_device *dev = cmd->se_dev;
183 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
184 	struct se_port *port, *l_port = cmd->se_lun->lun_sep;
185 	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
186 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
187 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *l_tg_pt_gp_mem;
188 	unsigned char *buf;
189 	unsigned char *ptr;
190 	u32 len = 4; /* Skip over RESERVED area in header */
191 	int alua_access_state, primary = 0, rc;
192 	u16 tg_pt_id, rtpi;
193 
194 	if (!l_port)
195 		return PYX_TRANSPORT_LU_COMM_FAILURE;
196 
197 	buf = transport_kmap_first_data_page(cmd);
198 
199 	/*
200 	 * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
201 	 * for the local tg_pt_gp.
202 	 */
203 	l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
204 	if (!l_tg_pt_gp_mem) {
205 		pr_err("Unable to access l_port->sep_alua_tg_pt_gp_mem\n");
206 		rc = PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
207 		goto out;
208 	}
209 	spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
210 	l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
211 	if (!l_tg_pt_gp) {
212 		spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
213 		pr_err("Unable to access *l_tg_pt_gp_mem->tg_pt_gp\n");
214 		rc = PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
215 		goto out;
216 	}
217 	rc = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
218 	spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
219 
220 	if (!rc) {
221 		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
222 				" while TPGS_EXPLICT_ALUA is disabled\n");
223 		rc = PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
224 		goto out;
225 	}
226 
227 	ptr = &buf[4]; /* Skip over RESERVED area in header */
228 
229 	while (len < cmd->data_length) {
230 		alua_access_state = (ptr[0] & 0x0f);
231 		/*
232 		 * Check the received ALUA access state, and determine if
233 		 * the state is a primary or secondary target port asymmetric
234 		 * access state.
235 		 */
236 		rc = core_alua_check_transition(alua_access_state, &primary);
237 		if (rc != 0) {
238 			/*
239 			 * If the SET TARGET PORT GROUPS attempts to establish
240 			 * an invalid combination of target port asymmetric
241 			 * access states or attempts to establish an
242 			 * unsupported target port asymmetric access state,
243 			 * then the command shall be terminated with CHECK
244 			 * CONDITION status, with the sense key set to ILLEGAL
245 			 * REQUEST, and the additional sense code set to INVALID
246 			 * FIELD IN PARAMETER LIST.
247 			 */
248 			rc = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
249 			goto out;
250 		}
251 		rc = -1;
252 		/*
253 		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
254 		 * specifies a primary target port asymmetric access state,
255 		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
256 		 * a primary target port group for which the primary target
257 		 * port asymmetric access state shall be changed. If the
258 		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
259 		 * port asymmetric access state, then the TARGET PORT GROUP OR
260 		 * TARGET PORT field specifies the relative target port
261 		 * identifier (see 3.1.120) of the target port for which the
262 		 * secondary target port asymmetric access state shall be
263 		 * changed.
264 		 */
265 		if (primary) {
266 			tg_pt_id = ((ptr[2] << 8) & 0xff);
267 			tg_pt_id |= (ptr[3] & 0xff);
268 			/*
269 			 * Locate the matching target port group ID from
270 			 * the global tg_pt_gp list
271 			 */
272 			spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
273 			list_for_each_entry(tg_pt_gp,
274 					&su_dev->t10_alua.tg_pt_gps_list,
275 					tg_pt_gp_list) {
276 				if (!tg_pt_gp->tg_pt_gp_valid_id)
277 					continue;
278 
279 				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
280 					continue;
281 
282 				atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
283 				smp_mb__after_atomic_inc();
284 				spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
285 
286 				rc = core_alua_do_port_transition(tg_pt_gp,
287 						dev, l_port, nacl,
288 						alua_access_state, 1);
289 
290 				spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
291 				atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
292 				smp_mb__after_atomic_dec();
293 				break;
294 			}
295 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
296 			/*
297 			 * If not matching target port group ID can be located
298 			 * throw an exception with ASCQ: INVALID_PARAMETER_LIST
299 			 */
300 			if (rc != 0) {
301 				rc = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
302 				goto out;
303 			}
304 		} else {
305 			/*
306 			 * Extact the RELATIVE TARGET PORT IDENTIFIER to identify
307 			 * the Target Port in question for the the incoming
308 			 * SET_TARGET_PORT_GROUPS op.
309 			 */
310 			rtpi = ((ptr[2] << 8) & 0xff);
311 			rtpi |= (ptr[3] & 0xff);
312 			/*
313 			 * Locate the matching relative target port identifer
314 			 * for the struct se_device storage object.
315 			 */
316 			spin_lock(&dev->se_port_lock);
317 			list_for_each_entry(port, &dev->dev_sep_list,
318 							sep_list) {
319 				if (port->sep_rtpi != rtpi)
320 					continue;
321 
322 				tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
323 				spin_unlock(&dev->se_port_lock);
324 
325 				rc = core_alua_set_tg_pt_secondary_state(
326 						tg_pt_gp_mem, port, 1, 1);
327 
328 				spin_lock(&dev->se_port_lock);
329 				break;
330 			}
331 			spin_unlock(&dev->se_port_lock);
332 			/*
333 			 * If not matching relative target port identifier can
334 			 * be located, throw an exception with ASCQ:
335 			 * INVALID_PARAMETER_LIST
336 			 */
337 			if (rc != 0) {
338 				rc = PYX_TRANSPORT_INVALID_PARAMETER_LIST;
339 				goto out;
340 			}
341 		}
342 
343 		ptr += 4;
344 		len += 4;
345 	}
346 
347 out:
348 	transport_kunmap_first_data_page(cmd);
349 	task->task_scsi_status = GOOD;
350 	transport_complete_task(task, 1);
351 	return 0;
352 }
353 
354 static inline int core_alua_state_nonoptimized(
355 	struct se_cmd *cmd,
356 	unsigned char *cdb,
357 	int nonop_delay_msecs,
358 	u8 *alua_ascq)
359 {
360 	/*
361 	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
362 	 * later to determine if processing of this cmd needs to be
363 	 * temporarily delayed for the Active/NonOptimized primary access state.
364 	 */
365 	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
366 	cmd->alua_nonop_delay = nonop_delay_msecs;
367 	return 0;
368 }
369 
370 static inline int core_alua_state_standby(
371 	struct se_cmd *cmd,
372 	unsigned char *cdb,
373 	u8 *alua_ascq)
374 {
375 	/*
376 	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
377 	 * spc4r17 section 5.9.2.4.4
378 	 */
379 	switch (cdb[0]) {
380 	case INQUIRY:
381 	case LOG_SELECT:
382 	case LOG_SENSE:
383 	case MODE_SELECT:
384 	case MODE_SENSE:
385 	case REPORT_LUNS:
386 	case RECEIVE_DIAGNOSTIC:
387 	case SEND_DIAGNOSTIC:
388 	case MAINTENANCE_IN:
389 		switch (cdb[1]) {
390 		case MI_REPORT_TARGET_PGS:
391 			return 0;
392 		default:
393 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
394 			return 1;
395 		}
396 	case MAINTENANCE_OUT:
397 		switch (cdb[1]) {
398 		case MO_SET_TARGET_PGS:
399 			return 0;
400 		default:
401 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
402 			return 1;
403 		}
404 	case REQUEST_SENSE:
405 	case PERSISTENT_RESERVE_IN:
406 	case PERSISTENT_RESERVE_OUT:
407 	case READ_BUFFER:
408 	case WRITE_BUFFER:
409 		return 0;
410 	default:
411 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
412 		return 1;
413 	}
414 
415 	return 0;
416 }
417 
418 static inline int core_alua_state_unavailable(
419 	struct se_cmd *cmd,
420 	unsigned char *cdb,
421 	u8 *alua_ascq)
422 {
423 	/*
424 	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
425 	 * spc4r17 section 5.9.2.4.5
426 	 */
427 	switch (cdb[0]) {
428 	case INQUIRY:
429 	case REPORT_LUNS:
430 	case MAINTENANCE_IN:
431 		switch (cdb[1]) {
432 		case MI_REPORT_TARGET_PGS:
433 			return 0;
434 		default:
435 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
436 			return 1;
437 		}
438 	case MAINTENANCE_OUT:
439 		switch (cdb[1]) {
440 		case MO_SET_TARGET_PGS:
441 			return 0;
442 		default:
443 			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
444 			return 1;
445 		}
446 	case REQUEST_SENSE:
447 	case READ_BUFFER:
448 	case WRITE_BUFFER:
449 		return 0;
450 	default:
451 		*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
452 		return 1;
453 	}
454 
455 	return 0;
456 }
457 
458 static inline int core_alua_state_transition(
459 	struct se_cmd *cmd,
460 	unsigned char *cdb,
461 	u8 *alua_ascq)
462 {
463 	/*
464 	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
465 	 * spc4r17 section 5.9.2.5
466 	 */
467 	switch (cdb[0]) {
468 	case INQUIRY:
469 	case REPORT_LUNS:
470 	case MAINTENANCE_IN:
471 		switch (cdb[1]) {
472 		case MI_REPORT_TARGET_PGS:
473 			return 0;
474 		default:
475 			*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
476 			return 1;
477 		}
478 	case REQUEST_SENSE:
479 	case READ_BUFFER:
480 	case WRITE_BUFFER:
481 		return 0;
482 	default:
483 		*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
484 		return 1;
485 	}
486 
487 	return 0;
488 }
489 
490 /*
491  * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
492  * in transport_cmd_sequencer().  This function is assigned to
493  * struct t10_alua *->state_check() in core_setup_alua()
494  */
495 static int core_alua_state_check_nop(
496 	struct se_cmd *cmd,
497 	unsigned char *cdb,
498 	u8 *alua_ascq)
499 {
500 	return 0;
501 }
502 
503 /*
504  * Used for alua_type SPC3_ALUA_EMULATED in transport_cmd_sequencer().
505  * This function is assigned to struct t10_alua *->state_check() in
506  * core_setup_alua()
507  *
508  * Also, this function can return three different return codes to
509  * signal transport_generic_cmd_sequencer()
510  *
511  * return 1: Is used to signal LUN not accecsable, and check condition/not ready
512  * return 0: Used to signal success
513  * reutrn -1: Used to signal failure, and invalid cdb field
514  */
515 static int core_alua_state_check(
516 	struct se_cmd *cmd,
517 	unsigned char *cdb,
518 	u8 *alua_ascq)
519 {
520 	struct se_lun *lun = cmd->se_lun;
521 	struct se_port *port = lun->lun_sep;
522 	struct t10_alua_tg_pt_gp *tg_pt_gp;
523 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
524 	int out_alua_state, nonop_delay_msecs;
525 
526 	if (!port)
527 		return 0;
528 	/*
529 	 * First, check for a struct se_port specific secondary ALUA target port
530 	 * access state: OFFLINE
531 	 */
532 	if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
533 		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
534 		pr_debug("ALUA: Got secondary offline status for local"
535 				" target port\n");
536 		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
537 		return 1;
538 	}
539 	 /*
540 	 * Second, obtain the struct t10_alua_tg_pt_gp_member pointer to the
541 	 * ALUA target port group, to obtain current ALUA access state.
542 	 * Otherwise look for the underlying struct se_device association with
543 	 * a ALUA logical unit group.
544 	 */
545 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
546 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
547 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
548 	out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
549 	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
550 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
551 	/*
552 	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a separate conditional
553 	 * statement so the compiler knows explicitly to check this case first.
554 	 * For the Optimized ALUA access state case, we want to process the
555 	 * incoming fabric cmd ASAP..
556 	 */
557 	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
558 		return 0;
559 
560 	switch (out_alua_state) {
561 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
562 		return core_alua_state_nonoptimized(cmd, cdb,
563 					nonop_delay_msecs, alua_ascq);
564 	case ALUA_ACCESS_STATE_STANDBY:
565 		return core_alua_state_standby(cmd, cdb, alua_ascq);
566 	case ALUA_ACCESS_STATE_UNAVAILABLE:
567 		return core_alua_state_unavailable(cmd, cdb, alua_ascq);
568 	case ALUA_ACCESS_STATE_TRANSITION:
569 		return core_alua_state_transition(cmd, cdb, alua_ascq);
570 	/*
571 	 * OFFLINE is a secondary ALUA target port group access state, that is
572 	 * handled above with struct se_port->sep_tg_pt_secondary_offline=1
573 	 */
574 	case ALUA_ACCESS_STATE_OFFLINE:
575 	default:
576 		pr_err("Unknown ALUA access state: 0x%02x\n",
577 				out_alua_state);
578 		return -EINVAL;
579 	}
580 
581 	return 0;
582 }
583 
584 /*
585  * Check implict and explict ALUA state change request.
586  */
587 static int core_alua_check_transition(int state, int *primary)
588 {
589 	switch (state) {
590 	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
591 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
592 	case ALUA_ACCESS_STATE_STANDBY:
593 	case ALUA_ACCESS_STATE_UNAVAILABLE:
594 		/*
595 		 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
596 		 * defined as primary target port asymmetric access states.
597 		 */
598 		*primary = 1;
599 		break;
600 	case ALUA_ACCESS_STATE_OFFLINE:
601 		/*
602 		 * OFFLINE state is defined as a secondary target port
603 		 * asymmetric access state.
604 		 */
605 		*primary = 0;
606 		break;
607 	default:
608 		pr_err("Unknown ALUA access state: 0x%02x\n", state);
609 		return -EINVAL;
610 	}
611 
612 	return 0;
613 }
614 
615 static char *core_alua_dump_state(int state)
616 {
617 	switch (state) {
618 	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
619 		return "Active/Optimized";
620 	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
621 		return "Active/NonOptimized";
622 	case ALUA_ACCESS_STATE_STANDBY:
623 		return "Standby";
624 	case ALUA_ACCESS_STATE_UNAVAILABLE:
625 		return "Unavailable";
626 	case ALUA_ACCESS_STATE_OFFLINE:
627 		return "Offline";
628 	default:
629 		return "Unknown";
630 	}
631 
632 	return NULL;
633 }
634 
635 char *core_alua_dump_status(int status)
636 {
637 	switch (status) {
638 	case ALUA_STATUS_NONE:
639 		return "None";
640 	case ALUA_STATUS_ALTERED_BY_EXPLICT_STPG:
641 		return "Altered by Explict STPG";
642 	case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
643 		return "Altered by Implict ALUA";
644 	default:
645 		return "Unknown";
646 	}
647 
648 	return NULL;
649 }
650 
651 /*
652  * Used by fabric modules to determine when we need to delay processing
653  * for the Active/NonOptimized paths..
654  */
655 int core_alua_check_nonop_delay(
656 	struct se_cmd *cmd)
657 {
658 	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
659 		return 0;
660 	if (in_interrupt())
661 		return 0;
662 	/*
663 	 * The ALUA Active/NonOptimized access state delay can be disabled
664 	 * in via configfs with a value of zero
665 	 */
666 	if (!cmd->alua_nonop_delay)
667 		return 0;
668 	/*
669 	 * struct se_cmd->alua_nonop_delay gets set by a target port group
670 	 * defined interval in core_alua_state_nonoptimized()
671 	 */
672 	msleep_interruptible(cmd->alua_nonop_delay);
673 	return 0;
674 }
675 EXPORT_SYMBOL(core_alua_check_nonop_delay);
676 
677 /*
678  * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
679  *
680  */
681 static int core_alua_write_tpg_metadata(
682 	const char *path,
683 	unsigned char *md_buf,
684 	u32 md_buf_len)
685 {
686 	mm_segment_t old_fs;
687 	struct file *file;
688 	struct iovec iov[1];
689 	int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
690 
691 	memset(iov, 0, sizeof(struct iovec));
692 
693 	file = filp_open(path, flags, 0600);
694 	if (IS_ERR(file) || !file || !file->f_dentry) {
695 		pr_err("filp_open(%s) for ALUA metadata failed\n",
696 			path);
697 		return -ENODEV;
698 	}
699 
700 	iov[0].iov_base = &md_buf[0];
701 	iov[0].iov_len = md_buf_len;
702 
703 	old_fs = get_fs();
704 	set_fs(get_ds());
705 	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
706 	set_fs(old_fs);
707 
708 	if (ret < 0) {
709 		pr_err("Error writing ALUA metadata file: %s\n", path);
710 		filp_close(file, NULL);
711 		return -EIO;
712 	}
713 	filp_close(file, NULL);
714 
715 	return 0;
716 }
717 
718 /*
719  * Called with tg_pt_gp->tg_pt_gp_md_mutex held
720  */
721 static int core_alua_update_tpg_primary_metadata(
722 	struct t10_alua_tg_pt_gp *tg_pt_gp,
723 	int primary_state,
724 	unsigned char *md_buf)
725 {
726 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
727 	struct t10_wwn *wwn = &su_dev->t10_wwn;
728 	char path[ALUA_METADATA_PATH_LEN];
729 	int len;
730 
731 	memset(path, 0, ALUA_METADATA_PATH_LEN);
732 
733 	len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_md_buf_len,
734 			"tg_pt_gp_id=%hu\n"
735 			"alua_access_state=0x%02x\n"
736 			"alua_access_status=0x%02x\n",
737 			tg_pt_gp->tg_pt_gp_id, primary_state,
738 			tg_pt_gp->tg_pt_gp_alua_access_status);
739 
740 	snprintf(path, ALUA_METADATA_PATH_LEN,
741 		"/var/target/alua/tpgs_%s/%s", &wwn->unit_serial[0],
742 		config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
743 
744 	return core_alua_write_tpg_metadata(path, md_buf, len);
745 }
746 
747 static int core_alua_do_transition_tg_pt(
748 	struct t10_alua_tg_pt_gp *tg_pt_gp,
749 	struct se_port *l_port,
750 	struct se_node_acl *nacl,
751 	unsigned char *md_buf,
752 	int new_state,
753 	int explict)
754 {
755 	struct se_dev_entry *se_deve;
756 	struct se_lun_acl *lacl;
757 	struct se_port *port;
758 	struct t10_alua_tg_pt_gp_member *mem;
759 	int old_state = 0;
760 	/*
761 	 * Save the old primary ALUA access state, and set the current state
762 	 * to ALUA_ACCESS_STATE_TRANSITION.
763 	 */
764 	old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
765 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
766 			ALUA_ACCESS_STATE_TRANSITION);
767 	tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
768 				ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
769 				ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
770 	/*
771 	 * Check for the optional ALUA primary state transition delay
772 	 */
773 	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
774 		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
775 
776 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
777 	list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
778 				tg_pt_gp_mem_list) {
779 		port = mem->tg_pt;
780 		/*
781 		 * After an implicit target port asymmetric access state
782 		 * change, a device server shall establish a unit attention
783 		 * condition for the initiator port associated with every I_T
784 		 * nexus with the additional sense code set to ASYMMETRIC
785 		 * ACCESS STATE CHAGED.
786 		 *
787 		 * After an explicit target port asymmetric access state
788 		 * change, a device server shall establish a unit attention
789 		 * condition with the additional sense code set to ASYMMETRIC
790 		 * ACCESS STATE CHANGED for the initiator port associated with
791 		 * every I_T nexus other than the I_T nexus on which the SET
792 		 * TARGET PORT GROUPS command
793 		 */
794 		atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
795 		smp_mb__after_atomic_inc();
796 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
797 
798 		spin_lock_bh(&port->sep_alua_lock);
799 		list_for_each_entry(se_deve, &port->sep_alua_list,
800 					alua_port_list) {
801 			lacl = se_deve->se_lun_acl;
802 			/*
803 			 * se_deve->se_lun_acl pointer may be NULL for a
804 			 * entry created without explict Node+MappedLUN ACLs
805 			 */
806 			if (!lacl)
807 				continue;
808 
809 			if (explict &&
810 			   (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
811 			   (l_port != NULL) && (l_port == port))
812 				continue;
813 
814 			core_scsi3_ua_allocate(lacl->se_lun_nacl,
815 				se_deve->mapped_lun, 0x2A,
816 				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
817 		}
818 		spin_unlock_bh(&port->sep_alua_lock);
819 
820 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
821 		atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
822 		smp_mb__after_atomic_dec();
823 	}
824 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
825 	/*
826 	 * Update the ALUA metadata buf that has been allocated in
827 	 * core_alua_do_port_transition(), this metadata will be written
828 	 * to struct file.
829 	 *
830 	 * Note that there is the case where we do not want to update the
831 	 * metadata when the saved metadata is being parsed in userspace
832 	 * when setting the existing port access state and access status.
833 	 *
834 	 * Also note that the failure to write out the ALUA metadata to
835 	 * struct file does NOT affect the actual ALUA transition.
836 	 */
837 	if (tg_pt_gp->tg_pt_gp_write_metadata) {
838 		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
839 		core_alua_update_tpg_primary_metadata(tg_pt_gp,
840 					new_state, md_buf);
841 		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
842 	}
843 	/*
844 	 * Set the current primary ALUA access state to the requested new state
845 	 */
846 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
847 
848 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
849 		" from primary access state %s to %s\n", (explict) ? "explict" :
850 		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
851 		tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
852 		core_alua_dump_state(new_state));
853 
854 	return 0;
855 }
856 
857 int core_alua_do_port_transition(
858 	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
859 	struct se_device *l_dev,
860 	struct se_port *l_port,
861 	struct se_node_acl *l_nacl,
862 	int new_state,
863 	int explict)
864 {
865 	struct se_device *dev;
866 	struct se_port *port;
867 	struct se_subsystem_dev *su_dev;
868 	struct se_node_acl *nacl;
869 	struct t10_alua_lu_gp *lu_gp;
870 	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
871 	struct t10_alua_tg_pt_gp *tg_pt_gp;
872 	unsigned char *md_buf;
873 	int primary;
874 
875 	if (core_alua_check_transition(new_state, &primary) != 0)
876 		return -EINVAL;
877 
878 	md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
879 	if (!md_buf) {
880 		pr_err("Unable to allocate buf for ALUA metadata\n");
881 		return -ENOMEM;
882 	}
883 
884 	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
885 	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
886 	lu_gp = local_lu_gp_mem->lu_gp;
887 	atomic_inc(&lu_gp->lu_gp_ref_cnt);
888 	smp_mb__after_atomic_inc();
889 	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
890 	/*
891 	 * For storage objects that are members of the 'default_lu_gp',
892 	 * we only do transition on the passed *l_tp_pt_gp, and not
893 	 * on all of the matching target port groups IDs in default_lu_gp.
894 	 */
895 	if (!lu_gp->lu_gp_id) {
896 		/*
897 		 * core_alua_do_transition_tg_pt() will always return
898 		 * success.
899 		 */
900 		core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
901 					md_buf, new_state, explict);
902 		atomic_dec(&lu_gp->lu_gp_ref_cnt);
903 		smp_mb__after_atomic_dec();
904 		kfree(md_buf);
905 		return 0;
906 	}
907 	/*
908 	 * For all other LU groups aside from 'default_lu_gp', walk all of
909 	 * the associated storage objects looking for a matching target port
910 	 * group ID from the local target port group.
911 	 */
912 	spin_lock(&lu_gp->lu_gp_lock);
913 	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
914 				lu_gp_mem_list) {
915 
916 		dev = lu_gp_mem->lu_gp_mem_dev;
917 		su_dev = dev->se_sub_dev;
918 		atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
919 		smp_mb__after_atomic_inc();
920 		spin_unlock(&lu_gp->lu_gp_lock);
921 
922 		spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
923 		list_for_each_entry(tg_pt_gp,
924 				&su_dev->t10_alua.tg_pt_gps_list,
925 				tg_pt_gp_list) {
926 
927 			if (!tg_pt_gp->tg_pt_gp_valid_id)
928 				continue;
929 			/*
930 			 * If the target behavior port asymmetric access state
931 			 * is changed for any target port group accessiable via
932 			 * a logical unit within a LU group, the target port
933 			 * behavior group asymmetric access states for the same
934 			 * target port group accessible via other logical units
935 			 * in that LU group will also change.
936 			 */
937 			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
938 				continue;
939 
940 			if (l_tg_pt_gp == tg_pt_gp) {
941 				port = l_port;
942 				nacl = l_nacl;
943 			} else {
944 				port = NULL;
945 				nacl = NULL;
946 			}
947 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
948 			smp_mb__after_atomic_inc();
949 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
950 			/*
951 			 * core_alua_do_transition_tg_pt() will always return
952 			 * success.
953 			 */
954 			core_alua_do_transition_tg_pt(tg_pt_gp, port,
955 					nacl, md_buf, new_state, explict);
956 
957 			spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
958 			atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
959 			smp_mb__after_atomic_dec();
960 		}
961 		spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
962 
963 		spin_lock(&lu_gp->lu_gp_lock);
964 		atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
965 		smp_mb__after_atomic_dec();
966 	}
967 	spin_unlock(&lu_gp->lu_gp_lock);
968 
969 	pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
970 		" Group IDs: %hu %s transition to primary state: %s\n",
971 		config_item_name(&lu_gp->lu_gp_group.cg_item),
972 		l_tg_pt_gp->tg_pt_gp_id, (explict) ? "explict" : "implict",
973 		core_alua_dump_state(new_state));
974 
975 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
976 	smp_mb__after_atomic_dec();
977 	kfree(md_buf);
978 	return 0;
979 }
980 
981 /*
982  * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
983  */
984 static int core_alua_update_tpg_secondary_metadata(
985 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
986 	struct se_port *port,
987 	unsigned char *md_buf,
988 	u32 md_buf_len)
989 {
990 	struct se_portal_group *se_tpg = port->sep_tpg;
991 	char path[ALUA_METADATA_PATH_LEN], wwn[ALUA_SECONDARY_METADATA_WWN_LEN];
992 	int len;
993 
994 	memset(path, 0, ALUA_METADATA_PATH_LEN);
995 	memset(wwn, 0, ALUA_SECONDARY_METADATA_WWN_LEN);
996 
997 	len = snprintf(wwn, ALUA_SECONDARY_METADATA_WWN_LEN, "%s",
998 			se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg));
999 
1000 	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL)
1001 		snprintf(wwn+len, ALUA_SECONDARY_METADATA_WWN_LEN-len, "+%hu",
1002 				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
1003 
1004 	len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
1005 			"alua_tg_pt_status=0x%02x\n",
1006 			atomic_read(&port->sep_tg_pt_secondary_offline),
1007 			port->sep_tg_pt_secondary_stat);
1008 
1009 	snprintf(path, ALUA_METADATA_PATH_LEN, "/var/target/alua/%s/%s/lun_%u",
1010 			se_tpg->se_tpg_tfo->get_fabric_name(), wwn,
1011 			port->sep_lun->unpacked_lun);
1012 
1013 	return core_alua_write_tpg_metadata(path, md_buf, len);
1014 }
1015 
1016 static int core_alua_set_tg_pt_secondary_state(
1017 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1018 	struct se_port *port,
1019 	int explict,
1020 	int offline)
1021 {
1022 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1023 	unsigned char *md_buf;
1024 	u32 md_buf_len;
1025 	int trans_delay_msecs;
1026 
1027 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1028 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1029 	if (!tg_pt_gp) {
1030 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1031 		pr_err("Unable to complete secondary state"
1032 				" transition\n");
1033 		return -EINVAL;
1034 	}
1035 	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1036 	/*
1037 	 * Set the secondary ALUA target port access state to OFFLINE
1038 	 * or release the previously secondary state for struct se_port
1039 	 */
1040 	if (offline)
1041 		atomic_set(&port->sep_tg_pt_secondary_offline, 1);
1042 	else
1043 		atomic_set(&port->sep_tg_pt_secondary_offline, 0);
1044 
1045 	md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
1046 	port->sep_tg_pt_secondary_stat = (explict) ?
1047 			ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
1048 			ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
1049 
1050 	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1051 		" to secondary access state: %s\n", (explict) ? "explict" :
1052 		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1053 		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1054 
1055 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1056 	/*
1057 	 * Do the optional transition delay after we set the secondary
1058 	 * ALUA access state.
1059 	 */
1060 	if (trans_delay_msecs != 0)
1061 		msleep_interruptible(trans_delay_msecs);
1062 	/*
1063 	 * See if we need to update the ALUA fabric port metadata for
1064 	 * secondary state and status
1065 	 */
1066 	if (port->sep_tg_pt_secondary_write_md) {
1067 		md_buf = kzalloc(md_buf_len, GFP_KERNEL);
1068 		if (!md_buf) {
1069 			pr_err("Unable to allocate md_buf for"
1070 				" secondary ALUA access metadata\n");
1071 			return -ENOMEM;
1072 		}
1073 		mutex_lock(&port->sep_tg_pt_md_mutex);
1074 		core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
1075 				md_buf, md_buf_len);
1076 		mutex_unlock(&port->sep_tg_pt_md_mutex);
1077 
1078 		kfree(md_buf);
1079 	}
1080 
1081 	return 0;
1082 }
1083 
1084 struct t10_alua_lu_gp *
1085 core_alua_allocate_lu_gp(const char *name, int def_group)
1086 {
1087 	struct t10_alua_lu_gp *lu_gp;
1088 
1089 	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1090 	if (!lu_gp) {
1091 		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1092 		return ERR_PTR(-ENOMEM);
1093 	}
1094 	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1095 	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1096 	spin_lock_init(&lu_gp->lu_gp_lock);
1097 	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1098 
1099 	if (def_group) {
1100 		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1101 		lu_gp->lu_gp_valid_id = 1;
1102 		alua_lu_gps_count++;
1103 	}
1104 
1105 	return lu_gp;
1106 }
1107 
1108 int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1109 {
1110 	struct t10_alua_lu_gp *lu_gp_tmp;
1111 	u16 lu_gp_id_tmp;
1112 	/*
1113 	 * The lu_gp->lu_gp_id may only be set once..
1114 	 */
1115 	if (lu_gp->lu_gp_valid_id) {
1116 		pr_warn("ALUA LU Group already has a valid ID,"
1117 			" ignoring request\n");
1118 		return -EINVAL;
1119 	}
1120 
1121 	spin_lock(&lu_gps_lock);
1122 	if (alua_lu_gps_count == 0x0000ffff) {
1123 		pr_err("Maximum ALUA alua_lu_gps_count:"
1124 				" 0x0000ffff reached\n");
1125 		spin_unlock(&lu_gps_lock);
1126 		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1127 		return -ENOSPC;
1128 	}
1129 again:
1130 	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1131 				alua_lu_gps_counter++;
1132 
1133 	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1134 		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1135 			if (!lu_gp_id)
1136 				goto again;
1137 
1138 			pr_warn("ALUA Logical Unit Group ID: %hu"
1139 				" already exists, ignoring request\n",
1140 				lu_gp_id);
1141 			spin_unlock(&lu_gps_lock);
1142 			return -EINVAL;
1143 		}
1144 	}
1145 
1146 	lu_gp->lu_gp_id = lu_gp_id_tmp;
1147 	lu_gp->lu_gp_valid_id = 1;
1148 	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1149 	alua_lu_gps_count++;
1150 	spin_unlock(&lu_gps_lock);
1151 
1152 	return 0;
1153 }
1154 
1155 static struct t10_alua_lu_gp_member *
1156 core_alua_allocate_lu_gp_mem(struct se_device *dev)
1157 {
1158 	struct t10_alua_lu_gp_member *lu_gp_mem;
1159 
1160 	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1161 	if (!lu_gp_mem) {
1162 		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1163 		return ERR_PTR(-ENOMEM);
1164 	}
1165 	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1166 	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1167 	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1168 
1169 	lu_gp_mem->lu_gp_mem_dev = dev;
1170 	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1171 
1172 	return lu_gp_mem;
1173 }
1174 
1175 void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1176 {
1177 	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1178 	/*
1179 	 * Once we have reached this point, config_item_put() has
1180 	 * already been called from target_core_alua_drop_lu_gp().
1181 	 *
1182 	 * Here, we remove the *lu_gp from the global list so that
1183 	 * no associations can be made while we are releasing
1184 	 * struct t10_alua_lu_gp.
1185 	 */
1186 	spin_lock(&lu_gps_lock);
1187 	atomic_set(&lu_gp->lu_gp_shutdown, 1);
1188 	list_del(&lu_gp->lu_gp_node);
1189 	alua_lu_gps_count--;
1190 	spin_unlock(&lu_gps_lock);
1191 	/*
1192 	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1193 	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1194 	 * released with core_alua_put_lu_gp_from_name()
1195 	 */
1196 	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1197 		cpu_relax();
1198 	/*
1199 	 * Release reference to struct t10_alua_lu_gp * from all associated
1200 	 * struct se_device.
1201 	 */
1202 	spin_lock(&lu_gp->lu_gp_lock);
1203 	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1204 				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1205 		if (lu_gp_mem->lu_gp_assoc) {
1206 			list_del(&lu_gp_mem->lu_gp_mem_list);
1207 			lu_gp->lu_gp_members--;
1208 			lu_gp_mem->lu_gp_assoc = 0;
1209 		}
1210 		spin_unlock(&lu_gp->lu_gp_lock);
1211 		/*
1212 		 *
1213 		 * lu_gp_mem is associated with a single
1214 		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1215 		 * struct se_device is released via core_alua_free_lu_gp_mem().
1216 		 *
1217 		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1218 		 * we want to re-assocate a given lu_gp_mem with default_lu_gp.
1219 		 */
1220 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1221 		if (lu_gp != default_lu_gp)
1222 			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1223 					default_lu_gp);
1224 		else
1225 			lu_gp_mem->lu_gp = NULL;
1226 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1227 
1228 		spin_lock(&lu_gp->lu_gp_lock);
1229 	}
1230 	spin_unlock(&lu_gp->lu_gp_lock);
1231 
1232 	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1233 }
1234 
1235 void core_alua_free_lu_gp_mem(struct se_device *dev)
1236 {
1237 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1238 	struct t10_alua *alua = &su_dev->t10_alua;
1239 	struct t10_alua_lu_gp *lu_gp;
1240 	struct t10_alua_lu_gp_member *lu_gp_mem;
1241 
1242 	if (alua->alua_type != SPC3_ALUA_EMULATED)
1243 		return;
1244 
1245 	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1246 	if (!lu_gp_mem)
1247 		return;
1248 
1249 	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1250 		cpu_relax();
1251 
1252 	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1253 	lu_gp = lu_gp_mem->lu_gp;
1254 	if (lu_gp) {
1255 		spin_lock(&lu_gp->lu_gp_lock);
1256 		if (lu_gp_mem->lu_gp_assoc) {
1257 			list_del(&lu_gp_mem->lu_gp_mem_list);
1258 			lu_gp->lu_gp_members--;
1259 			lu_gp_mem->lu_gp_assoc = 0;
1260 		}
1261 		spin_unlock(&lu_gp->lu_gp_lock);
1262 		lu_gp_mem->lu_gp = NULL;
1263 	}
1264 	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1265 
1266 	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1267 }
1268 
1269 struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1270 {
1271 	struct t10_alua_lu_gp *lu_gp;
1272 	struct config_item *ci;
1273 
1274 	spin_lock(&lu_gps_lock);
1275 	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1276 		if (!lu_gp->lu_gp_valid_id)
1277 			continue;
1278 		ci = &lu_gp->lu_gp_group.cg_item;
1279 		if (!strcmp(config_item_name(ci), name)) {
1280 			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1281 			spin_unlock(&lu_gps_lock);
1282 			return lu_gp;
1283 		}
1284 	}
1285 	spin_unlock(&lu_gps_lock);
1286 
1287 	return NULL;
1288 }
1289 
1290 void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1291 {
1292 	spin_lock(&lu_gps_lock);
1293 	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1294 	spin_unlock(&lu_gps_lock);
1295 }
1296 
1297 /*
1298  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1299  */
1300 void __core_alua_attach_lu_gp_mem(
1301 	struct t10_alua_lu_gp_member *lu_gp_mem,
1302 	struct t10_alua_lu_gp *lu_gp)
1303 {
1304 	spin_lock(&lu_gp->lu_gp_lock);
1305 	lu_gp_mem->lu_gp = lu_gp;
1306 	lu_gp_mem->lu_gp_assoc = 1;
1307 	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1308 	lu_gp->lu_gp_members++;
1309 	spin_unlock(&lu_gp->lu_gp_lock);
1310 }
1311 
1312 /*
1313  * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1314  */
1315 void __core_alua_drop_lu_gp_mem(
1316 	struct t10_alua_lu_gp_member *lu_gp_mem,
1317 	struct t10_alua_lu_gp *lu_gp)
1318 {
1319 	spin_lock(&lu_gp->lu_gp_lock);
1320 	list_del(&lu_gp_mem->lu_gp_mem_list);
1321 	lu_gp_mem->lu_gp = NULL;
1322 	lu_gp_mem->lu_gp_assoc = 0;
1323 	lu_gp->lu_gp_members--;
1324 	spin_unlock(&lu_gp->lu_gp_lock);
1325 }
1326 
1327 struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(
1328 	struct se_subsystem_dev *su_dev,
1329 	const char *name,
1330 	int def_group)
1331 {
1332 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1333 
1334 	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1335 	if (!tg_pt_gp) {
1336 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1337 		return NULL;
1338 	}
1339 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1340 	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
1341 	mutex_init(&tg_pt_gp->tg_pt_gp_md_mutex);
1342 	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1343 	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1344 	tg_pt_gp->tg_pt_gp_su_dev = su_dev;
1345 	tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
1346 	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
1347 		ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
1348 	/*
1349 	 * Enable both explict and implict ALUA support by default
1350 	 */
1351 	tg_pt_gp->tg_pt_gp_alua_access_type =
1352 			TPGS_EXPLICT_ALUA | TPGS_IMPLICT_ALUA;
1353 	/*
1354 	 * Set the default Active/NonOptimized Delay in milliseconds
1355 	 */
1356 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1357 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1358 
1359 	if (def_group) {
1360 		spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1361 		tg_pt_gp->tg_pt_gp_id =
1362 				su_dev->t10_alua.alua_tg_pt_gps_counter++;
1363 		tg_pt_gp->tg_pt_gp_valid_id = 1;
1364 		su_dev->t10_alua.alua_tg_pt_gps_count++;
1365 		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1366 			      &su_dev->t10_alua.tg_pt_gps_list);
1367 		spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1368 	}
1369 
1370 	return tg_pt_gp;
1371 }
1372 
1373 int core_alua_set_tg_pt_gp_id(
1374 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1375 	u16 tg_pt_gp_id)
1376 {
1377 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1378 	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1379 	u16 tg_pt_gp_id_tmp;
1380 	/*
1381 	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1382 	 */
1383 	if (tg_pt_gp->tg_pt_gp_valid_id) {
1384 		pr_warn("ALUA TG PT Group already has a valid ID,"
1385 			" ignoring request\n");
1386 		return -EINVAL;
1387 	}
1388 
1389 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1390 	if (su_dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1391 		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1392 			" 0x0000ffff reached\n");
1393 		spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1394 		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1395 		return -ENOSPC;
1396 	}
1397 again:
1398 	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1399 			su_dev->t10_alua.alua_tg_pt_gps_counter++;
1400 
1401 	list_for_each_entry(tg_pt_gp_tmp, &su_dev->t10_alua.tg_pt_gps_list,
1402 			tg_pt_gp_list) {
1403 		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1404 			if (!tg_pt_gp_id)
1405 				goto again;
1406 
1407 			pr_err("ALUA Target Port Group ID: %hu already"
1408 				" exists, ignoring request\n", tg_pt_gp_id);
1409 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1410 			return -EINVAL;
1411 		}
1412 	}
1413 
1414 	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1415 	tg_pt_gp->tg_pt_gp_valid_id = 1;
1416 	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1417 			&su_dev->t10_alua.tg_pt_gps_list);
1418 	su_dev->t10_alua.alua_tg_pt_gps_count++;
1419 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1420 
1421 	return 0;
1422 }
1423 
1424 struct t10_alua_tg_pt_gp_member *core_alua_allocate_tg_pt_gp_mem(
1425 	struct se_port *port)
1426 {
1427 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1428 
1429 	tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
1430 				GFP_KERNEL);
1431 	if (!tg_pt_gp_mem) {
1432 		pr_err("Unable to allocate struct t10_alua_tg_pt_gp_member\n");
1433 		return ERR_PTR(-ENOMEM);
1434 	}
1435 	INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1436 	spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1437 	atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
1438 
1439 	tg_pt_gp_mem->tg_pt = port;
1440 	port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
1441 	atomic_set(&port->sep_tg_pt_gp_active, 1);
1442 
1443 	return tg_pt_gp_mem;
1444 }
1445 
1446 void core_alua_free_tg_pt_gp(
1447 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1448 {
1449 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1450 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
1451 	/*
1452 	 * Once we have reached this point, config_item_put() has already
1453 	 * been called from target_core_alua_drop_tg_pt_gp().
1454 	 *
1455 	 * Here we remove *tg_pt_gp from the global list so that
1456 	 * no assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
1457 	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1458 	 */
1459 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1460 	list_del(&tg_pt_gp->tg_pt_gp_list);
1461 	su_dev->t10_alua.alua_tg_pt_gps_counter--;
1462 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1463 	/*
1464 	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1465 	 * core_alua_get_tg_pt_gp_by_name() in
1466 	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1467 	 * to be released with core_alua_put_tg_pt_gp_from_name().
1468 	 */
1469 	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1470 		cpu_relax();
1471 	/*
1472 	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1473 	 * struct se_port.
1474 	 */
1475 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1476 	list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
1477 			&tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
1478 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1479 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1480 			tg_pt_gp->tg_pt_gp_members--;
1481 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1482 		}
1483 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1484 		/*
1485 		 * tg_pt_gp_mem is associated with a single
1486 		 * se_port->sep_alua_tg_pt_gp_mem, and is released via
1487 		 * core_alua_free_tg_pt_gp_mem().
1488 		 *
1489 		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1490 		 * assume we want to re-assocate a given tg_pt_gp_mem with
1491 		 * default_tg_pt_gp.
1492 		 */
1493 		spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1494 		if (tg_pt_gp != su_dev->t10_alua.default_tg_pt_gp) {
1495 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1496 					su_dev->t10_alua.default_tg_pt_gp);
1497 		} else
1498 			tg_pt_gp_mem->tg_pt_gp = NULL;
1499 		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1500 
1501 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1502 	}
1503 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1504 
1505 	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1506 }
1507 
1508 void core_alua_free_tg_pt_gp_mem(struct se_port *port)
1509 {
1510 	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1511 	struct t10_alua *alua = &su_dev->t10_alua;
1512 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1513 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1514 
1515 	if (alua->alua_type != SPC3_ALUA_EMULATED)
1516 		return;
1517 
1518 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1519 	if (!tg_pt_gp_mem)
1520 		return;
1521 
1522 	while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
1523 		cpu_relax();
1524 
1525 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1526 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1527 	if (tg_pt_gp) {
1528 		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1529 		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
1530 			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1531 			tg_pt_gp->tg_pt_gp_members--;
1532 			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1533 		}
1534 		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1535 		tg_pt_gp_mem->tg_pt_gp = NULL;
1536 	}
1537 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1538 
1539 	kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
1540 }
1541 
1542 static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1543 	struct se_subsystem_dev *su_dev,
1544 	const char *name)
1545 {
1546 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1547 	struct config_item *ci;
1548 
1549 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1550 	list_for_each_entry(tg_pt_gp, &su_dev->t10_alua.tg_pt_gps_list,
1551 			tg_pt_gp_list) {
1552 		if (!tg_pt_gp->tg_pt_gp_valid_id)
1553 			continue;
1554 		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1555 		if (!strcmp(config_item_name(ci), name)) {
1556 			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1557 			spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1558 			return tg_pt_gp;
1559 		}
1560 	}
1561 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1562 
1563 	return NULL;
1564 }
1565 
1566 static void core_alua_put_tg_pt_gp_from_name(
1567 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1568 {
1569 	struct se_subsystem_dev *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
1570 
1571 	spin_lock(&su_dev->t10_alua.tg_pt_gps_lock);
1572 	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1573 	spin_unlock(&su_dev->t10_alua.tg_pt_gps_lock);
1574 }
1575 
1576 /*
1577  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1578  */
1579 void __core_alua_attach_tg_pt_gp_mem(
1580 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1581 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1582 {
1583 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1584 	tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
1585 	tg_pt_gp_mem->tg_pt_gp_assoc = 1;
1586 	list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
1587 			&tg_pt_gp->tg_pt_gp_mem_list);
1588 	tg_pt_gp->tg_pt_gp_members++;
1589 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1590 }
1591 
1592 /*
1593  * Called with struct t10_alua_tg_pt_gp_member->tg_pt_gp_mem_lock held
1594  */
1595 static void __core_alua_drop_tg_pt_gp_mem(
1596 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem,
1597 	struct t10_alua_tg_pt_gp *tg_pt_gp)
1598 {
1599 	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1600 	list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
1601 	tg_pt_gp_mem->tg_pt_gp = NULL;
1602 	tg_pt_gp_mem->tg_pt_gp_assoc = 0;
1603 	tg_pt_gp->tg_pt_gp_members--;
1604 	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1605 }
1606 
1607 ssize_t core_alua_show_tg_pt_gp_info(struct se_port *port, char *page)
1608 {
1609 	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1610 	struct config_item *tg_pt_ci;
1611 	struct t10_alua *alua = &su_dev->t10_alua;
1612 	struct t10_alua_tg_pt_gp *tg_pt_gp;
1613 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1614 	ssize_t len = 0;
1615 
1616 	if (alua->alua_type != SPC3_ALUA_EMULATED)
1617 		return len;
1618 
1619 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1620 	if (!tg_pt_gp_mem)
1621 		return len;
1622 
1623 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1624 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1625 	if (tg_pt_gp) {
1626 		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1627 		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1628 			" %hu\nTG Port Primary Access State: %s\nTG Port "
1629 			"Primary Access Status: %s\nTG Port Secondary Access"
1630 			" State: %s\nTG Port Secondary Access Status: %s\n",
1631 			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1632 			core_alua_dump_state(atomic_read(
1633 					&tg_pt_gp->tg_pt_gp_alua_access_state)),
1634 			core_alua_dump_status(
1635 				tg_pt_gp->tg_pt_gp_alua_access_status),
1636 			(atomic_read(&port->sep_tg_pt_secondary_offline)) ?
1637 			"Offline" : "None",
1638 			core_alua_dump_status(port->sep_tg_pt_secondary_stat));
1639 	}
1640 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1641 
1642 	return len;
1643 }
1644 
1645 ssize_t core_alua_store_tg_pt_gp_info(
1646 	struct se_port *port,
1647 	const char *page,
1648 	size_t count)
1649 {
1650 	struct se_portal_group *tpg;
1651 	struct se_lun *lun;
1652 	struct se_subsystem_dev *su_dev = port->sep_lun->lun_se_dev->se_sub_dev;
1653 	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1654 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1655 	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1656 	int move = 0;
1657 
1658 	tpg = port->sep_tpg;
1659 	lun = port->sep_lun;
1660 
1661 	if (su_dev->t10_alua.alua_type != SPC3_ALUA_EMULATED) {
1662 		pr_warn("SPC3_ALUA_EMULATED not enabled for"
1663 			" %s/tpgt_%hu/%s\n", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1664 			tpg->se_tpg_tfo->tpg_get_tag(tpg),
1665 			config_item_name(&lun->lun_group.cg_item));
1666 		return -EINVAL;
1667 	}
1668 
1669 	if (count > TG_PT_GROUP_NAME_BUF) {
1670 		pr_err("ALUA Target Port Group alias too large!\n");
1671 		return -EINVAL;
1672 	}
1673 	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1674 	memcpy(buf, page, count);
1675 	/*
1676 	 * Any ALUA target port group alias besides "NULL" means we will be
1677 	 * making a new group association.
1678 	 */
1679 	if (strcmp(strstrip(buf), "NULL")) {
1680 		/*
1681 		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1682 		 * struct t10_alua_tg_pt_gp.  This reference is released with
1683 		 * core_alua_put_tg_pt_gp_from_name() below.
1684 		 */
1685 		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(su_dev,
1686 					strstrip(buf));
1687 		if (!tg_pt_gp_new)
1688 			return -ENODEV;
1689 	}
1690 	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
1691 	if (!tg_pt_gp_mem) {
1692 		if (tg_pt_gp_new)
1693 			core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1694 		pr_err("NULL struct se_port->sep_alua_tg_pt_gp_mem pointer\n");
1695 		return -EINVAL;
1696 	}
1697 
1698 	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1699 	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
1700 	if (tg_pt_gp) {
1701 		/*
1702 		 * Clearing an existing tg_pt_gp association, and replacing
1703 		 * with the default_tg_pt_gp.
1704 		 */
1705 		if (!tg_pt_gp_new) {
1706 			pr_debug("Target_Core_ConfigFS: Moving"
1707 				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
1708 				" alua/%s, ID: %hu back to"
1709 				" default_tg_pt_gp\n",
1710 				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1711 				tpg->se_tpg_tfo->tpg_get_tag(tpg),
1712 				config_item_name(&lun->lun_group.cg_item),
1713 				config_item_name(
1714 					&tg_pt_gp->tg_pt_gp_group.cg_item),
1715 				tg_pt_gp->tg_pt_gp_id);
1716 
1717 			__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1718 			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
1719 					su_dev->t10_alua.default_tg_pt_gp);
1720 			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1721 
1722 			return count;
1723 		}
1724 		/*
1725 		 * Removing existing association of tg_pt_gp_mem with tg_pt_gp
1726 		 */
1727 		__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
1728 		move = 1;
1729 	}
1730 	/*
1731 	 * Associate tg_pt_gp_mem with tg_pt_gp_new.
1732 	 */
1733 	__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
1734 	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
1735 	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1736 		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
1737 		"Moving" : "Adding", 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(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1741 		tg_pt_gp_new->tg_pt_gp_id);
1742 
1743 	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1744 	return count;
1745 }
1746 
1747 ssize_t core_alua_show_access_type(
1748 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1749 	char *page)
1750 {
1751 	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
1752 	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
1753 		return sprintf(page, "Implict and Explict\n");
1754 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
1755 		return sprintf(page, "Implict\n");
1756 	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
1757 		return sprintf(page, "Explict\n");
1758 	else
1759 		return sprintf(page, "None\n");
1760 }
1761 
1762 ssize_t core_alua_store_access_type(
1763 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1764 	const char *page,
1765 	size_t count)
1766 {
1767 	unsigned long tmp;
1768 	int ret;
1769 
1770 	ret = strict_strtoul(page, 0, &tmp);
1771 	if (ret < 0) {
1772 		pr_err("Unable to extract alua_access_type\n");
1773 		return -EINVAL;
1774 	}
1775 	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
1776 		pr_err("Illegal value for alua_access_type:"
1777 				" %lu\n", tmp);
1778 		return -EINVAL;
1779 	}
1780 	if (tmp == 3)
1781 		tg_pt_gp->tg_pt_gp_alua_access_type =
1782 			TPGS_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
1783 	else if (tmp == 2)
1784 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
1785 	else if (tmp == 1)
1786 		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
1787 	else
1788 		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
1789 
1790 	return count;
1791 }
1792 
1793 ssize_t core_alua_show_nonop_delay_msecs(
1794 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1795 	char *page)
1796 {
1797 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
1798 }
1799 
1800 ssize_t core_alua_store_nonop_delay_msecs(
1801 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1802 	const char *page,
1803 	size_t count)
1804 {
1805 	unsigned long tmp;
1806 	int ret;
1807 
1808 	ret = strict_strtoul(page, 0, &tmp);
1809 	if (ret < 0) {
1810 		pr_err("Unable to extract nonop_delay_msecs\n");
1811 		return -EINVAL;
1812 	}
1813 	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
1814 		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
1815 			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
1816 			ALUA_MAX_NONOP_DELAY_MSECS);
1817 		return -EINVAL;
1818 	}
1819 	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
1820 
1821 	return count;
1822 }
1823 
1824 ssize_t core_alua_show_trans_delay_msecs(
1825 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1826 	char *page)
1827 {
1828 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1829 }
1830 
1831 ssize_t core_alua_store_trans_delay_msecs(
1832 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1833 	const char *page,
1834 	size_t count)
1835 {
1836 	unsigned long tmp;
1837 	int ret;
1838 
1839 	ret = strict_strtoul(page, 0, &tmp);
1840 	if (ret < 0) {
1841 		pr_err("Unable to extract trans_delay_msecs\n");
1842 		return -EINVAL;
1843 	}
1844 	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
1845 		pr_err("Passed trans_delay_msecs: %lu, exceeds"
1846 			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
1847 			ALUA_MAX_TRANS_DELAY_MSECS);
1848 		return -EINVAL;
1849 	}
1850 	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
1851 
1852 	return count;
1853 }
1854 
1855 ssize_t core_alua_show_preferred_bit(
1856 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1857 	char *page)
1858 {
1859 	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
1860 }
1861 
1862 ssize_t core_alua_store_preferred_bit(
1863 	struct t10_alua_tg_pt_gp *tg_pt_gp,
1864 	const char *page,
1865 	size_t count)
1866 {
1867 	unsigned long tmp;
1868 	int ret;
1869 
1870 	ret = strict_strtoul(page, 0, &tmp);
1871 	if (ret < 0) {
1872 		pr_err("Unable to extract preferred ALUA value\n");
1873 		return -EINVAL;
1874 	}
1875 	if ((tmp != 0) && (tmp != 1)) {
1876 		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
1877 		return -EINVAL;
1878 	}
1879 	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
1880 
1881 	return count;
1882 }
1883 
1884 ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
1885 {
1886 	if (!lun->lun_sep)
1887 		return -ENODEV;
1888 
1889 	return sprintf(page, "%d\n",
1890 		atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
1891 }
1892 
1893 ssize_t core_alua_store_offline_bit(
1894 	struct se_lun *lun,
1895 	const char *page,
1896 	size_t count)
1897 {
1898 	struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem;
1899 	unsigned long tmp;
1900 	int ret;
1901 
1902 	if (!lun->lun_sep)
1903 		return -ENODEV;
1904 
1905 	ret = strict_strtoul(page, 0, &tmp);
1906 	if (ret < 0) {
1907 		pr_err("Unable to extract alua_tg_pt_offline value\n");
1908 		return -EINVAL;
1909 	}
1910 	if ((tmp != 0) && (tmp != 1)) {
1911 		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
1912 				tmp);
1913 		return -EINVAL;
1914 	}
1915 	tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
1916 	if (!tg_pt_gp_mem) {
1917 		pr_err("Unable to locate *tg_pt_gp_mem\n");
1918 		return -EINVAL;
1919 	}
1920 
1921 	ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
1922 			lun->lun_sep, 0, (int)tmp);
1923 	if (ret < 0)
1924 		return -EINVAL;
1925 
1926 	return count;
1927 }
1928 
1929 ssize_t core_alua_show_secondary_status(
1930 	struct se_lun *lun,
1931 	char *page)
1932 {
1933 	return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
1934 }
1935 
1936 ssize_t core_alua_store_secondary_status(
1937 	struct se_lun *lun,
1938 	const char *page,
1939 	size_t count)
1940 {
1941 	unsigned long tmp;
1942 	int ret;
1943 
1944 	ret = strict_strtoul(page, 0, &tmp);
1945 	if (ret < 0) {
1946 		pr_err("Unable to extract alua_tg_pt_status\n");
1947 		return -EINVAL;
1948 	}
1949 	if ((tmp != ALUA_STATUS_NONE) &&
1950 	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
1951 	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
1952 		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
1953 				tmp);
1954 		return -EINVAL;
1955 	}
1956 	lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
1957 
1958 	return count;
1959 }
1960 
1961 ssize_t core_alua_show_secondary_write_metadata(
1962 	struct se_lun *lun,
1963 	char *page)
1964 {
1965 	return sprintf(page, "%d\n",
1966 			lun->lun_sep->sep_tg_pt_secondary_write_md);
1967 }
1968 
1969 ssize_t core_alua_store_secondary_write_metadata(
1970 	struct se_lun *lun,
1971 	const char *page,
1972 	size_t count)
1973 {
1974 	unsigned long tmp;
1975 	int ret;
1976 
1977 	ret = strict_strtoul(page, 0, &tmp);
1978 	if (ret < 0) {
1979 		pr_err("Unable to extract alua_tg_pt_write_md\n");
1980 		return -EINVAL;
1981 	}
1982 	if ((tmp != 0) && (tmp != 1)) {
1983 		pr_err("Illegal value for alua_tg_pt_write_md:"
1984 				" %lu\n", tmp);
1985 		return -EINVAL;
1986 	}
1987 	lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
1988 
1989 	return count;
1990 }
1991 
1992 int core_setup_alua(struct se_device *dev, int force_pt)
1993 {
1994 	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
1995 	struct t10_alua *alua = &su_dev->t10_alua;
1996 	struct t10_alua_lu_gp_member *lu_gp_mem;
1997 	/*
1998 	 * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
1999 	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
2000 	 * cause a problem because libata and some SATA RAID HBAs appear
2001 	 * under Linux/SCSI, but emulate SCSI logic themselves.
2002 	 */
2003 	if (((dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
2004 	    !(dev->se_sub_dev->se_dev_attrib.emulate_alua)) || force_pt) {
2005 		alua->alua_type = SPC_ALUA_PASSTHROUGH;
2006 		alua->alua_state_check = &core_alua_state_check_nop;
2007 		pr_debug("%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
2008 			" emulation\n", dev->transport->name);
2009 		return 0;
2010 	}
2011 	/*
2012 	 * If SPC-3 or above is reported by real or emulated struct se_device,
2013 	 * use emulated ALUA.
2014 	 */
2015 	if (dev->transport->get_device_rev(dev) >= SCSI_3) {
2016 		pr_debug("%s: Enabling ALUA Emulation for SPC-3"
2017 			" device\n", dev->transport->name);
2018 		/*
2019 		 * Associate this struct se_device with the default ALUA
2020 		 * LUN Group.
2021 		 */
2022 		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2023 		if (IS_ERR(lu_gp_mem))
2024 			return PTR_ERR(lu_gp_mem);
2025 
2026 		alua->alua_type = SPC3_ALUA_EMULATED;
2027 		alua->alua_state_check = &core_alua_state_check;
2028 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2029 		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2030 				default_lu_gp);
2031 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2032 
2033 		pr_debug("%s: Adding to default ALUA LU Group:"
2034 			" core/alua/lu_gps/default_lu_gp\n",
2035 			dev->transport->name);
2036 	} else {
2037 		alua->alua_type = SPC2_ALUA_DISABLED;
2038 		alua->alua_state_check = &core_alua_state_check_nop;
2039 		pr_debug("%s: Disabling ALUA Emulation for SPC-2"
2040 			" device\n", dev->transport->name);
2041 	}
2042 
2043 	return 0;
2044 }
2045