1 /*******************************************************************************
2  * Filename:  target_core_tpg.c
3  *
4  * This file contains generic Target Portal Group related functions.
5  *
6  * (c) Copyright 2002-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/net.h>
27 #include <linux/string.h>
28 #include <linux/timer.h>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
31 #include <linux/in.h>
32 #include <linux/export.h>
33 #include <net/sock.h>
34 #include <net/tcp.h>
35 #include <scsi/scsi_proto.h>
36 
37 #include <target/target_core_base.h>
38 #include <target/target_core_backend.h>
39 #include <target/target_core_fabric.h>
40 
41 #include "target_core_internal.h"
42 #include "target_core_alua.h"
43 #include "target_core_pr.h"
44 #include "target_core_ua.h"
45 
46 extern struct se_device *g_lun0_dev;
47 
48 static DEFINE_SPINLOCK(tpg_lock);
49 static LIST_HEAD(tpg_list);
50 
51 /*	__core_tpg_get_initiator_node_acl():
52  *
53  *	mutex_lock(&tpg->acl_node_mutex); must be held when calling
54  */
55 struct se_node_acl *__core_tpg_get_initiator_node_acl(
56 	struct se_portal_group *tpg,
57 	const char *initiatorname)
58 {
59 	struct se_node_acl *acl;
60 
61 	list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
62 		if (!strcmp(acl->initiatorname, initiatorname))
63 			return acl;
64 	}
65 
66 	return NULL;
67 }
68 
69 /*	core_tpg_get_initiator_node_acl():
70  *
71  *
72  */
73 struct se_node_acl *core_tpg_get_initiator_node_acl(
74 	struct se_portal_group *tpg,
75 	unsigned char *initiatorname)
76 {
77 	struct se_node_acl *acl;
78 	/*
79 	 * Obtain se_node_acl->acl_kref using fabric driver provided
80 	 * initiatorname[] during node acl endpoint lookup driven by
81 	 * new se_session login.
82 	 *
83 	 * The reference is held until se_session shutdown -> release
84 	 * occurs via fabric driver invoked transport_deregister_session()
85 	 * or transport_free_session() code.
86 	 */
87 	mutex_lock(&tpg->acl_node_mutex);
88 	acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
89 	if (acl) {
90 		if (!kref_get_unless_zero(&acl->acl_kref))
91 			acl = NULL;
92 	}
93 	mutex_unlock(&tpg->acl_node_mutex);
94 
95 	return acl;
96 }
97 EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);
98 
99 void core_allocate_nexus_loss_ua(
100 	struct se_node_acl *nacl)
101 {
102 	struct se_dev_entry *deve;
103 
104 	if (!nacl)
105 		return;
106 
107 	rcu_read_lock();
108 	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link)
109 		core_scsi3_ua_allocate(deve, 0x29,
110 			ASCQ_29H_NEXUS_LOSS_OCCURRED);
111 	rcu_read_unlock();
112 }
113 EXPORT_SYMBOL(core_allocate_nexus_loss_ua);
114 
115 /*	core_tpg_add_node_to_devs():
116  *
117  *
118  */
119 void core_tpg_add_node_to_devs(
120 	struct se_node_acl *acl,
121 	struct se_portal_group *tpg,
122 	struct se_lun *lun_orig)
123 {
124 	bool lun_access_ro = true;
125 	struct se_lun *lun;
126 	struct se_device *dev;
127 
128 	mutex_lock(&tpg->tpg_lun_mutex);
129 	hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link) {
130 		if (lun_orig && lun != lun_orig)
131 			continue;
132 
133 		dev = rcu_dereference_check(lun->lun_se_dev,
134 					    lockdep_is_held(&tpg->tpg_lun_mutex));
135 		/*
136 		 * By default in LIO-Target $FABRIC_MOD,
137 		 * demo_mode_write_protect is ON, or READ_ONLY;
138 		 */
139 		if (!tpg->se_tpg_tfo->tpg_check_demo_mode_write_protect(tpg)) {
140 			lun_access_ro = false;
141 		} else {
142 			/*
143 			 * Allow only optical drives to issue R/W in default RO
144 			 * demo mode.
145 			 */
146 			if (dev->transport->get_device_type(dev) == TYPE_DISK)
147 				lun_access_ro = true;
148 			else
149 				lun_access_ro = false;
150 		}
151 
152 		pr_debug("TARGET_CORE[%s]->TPG[%u]_LUN[%llu] - Adding %s"
153 			" access for LUN in Demo Mode\n",
154 			tpg->se_tpg_tfo->get_fabric_name(),
155 			tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
156 			lun_access_ro ? "READ-ONLY" : "READ-WRITE");
157 
158 		core_enable_device_list_for_node(lun, NULL, lun->unpacked_lun,
159 						 lun_access_ro, acl, tpg);
160 		/*
161 		 * Check to see if there are any existing persistent reservation
162 		 * APTPL pre-registrations that need to be enabled for this dynamic
163 		 * LUN ACL now..
164 		 */
165 		core_scsi3_check_aptpl_registration(dev, tpg, lun, acl,
166 						    lun->unpacked_lun);
167 	}
168 	mutex_unlock(&tpg->tpg_lun_mutex);
169 }
170 
171 static void
172 target_set_nacl_queue_depth(struct se_portal_group *tpg,
173 			    struct se_node_acl *acl, u32 queue_depth)
174 {
175 	acl->queue_depth = queue_depth;
176 
177 	if (!acl->queue_depth) {
178 		pr_warn("Queue depth for %s Initiator Node: %s is 0,"
179 			"defaulting to 1.\n", tpg->se_tpg_tfo->get_fabric_name(),
180 			acl->initiatorname);
181 		acl->queue_depth = 1;
182 	}
183 }
184 
185 static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg,
186 		const unsigned char *initiatorname)
187 {
188 	struct se_node_acl *acl;
189 	u32 queue_depth;
190 
191 	acl = kzalloc(max(sizeof(*acl), tpg->se_tpg_tfo->node_acl_size),
192 			GFP_KERNEL);
193 	if (!acl)
194 		return NULL;
195 
196 	INIT_LIST_HEAD(&acl->acl_list);
197 	INIT_LIST_HEAD(&acl->acl_sess_list);
198 	INIT_HLIST_HEAD(&acl->lun_entry_hlist);
199 	kref_init(&acl->acl_kref);
200 	init_completion(&acl->acl_free_comp);
201 	spin_lock_init(&acl->nacl_sess_lock);
202 	mutex_init(&acl->lun_entry_mutex);
203 	atomic_set(&acl->acl_pr_ref_count, 0);
204 
205 	if (tpg->se_tpg_tfo->tpg_get_default_depth)
206 		queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
207 	else
208 		queue_depth = 1;
209 	target_set_nacl_queue_depth(tpg, acl, queue_depth);
210 
211 	snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
212 	acl->se_tpg = tpg;
213 	acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
214 
215 	tpg->se_tpg_tfo->set_default_node_attributes(acl);
216 
217 	return acl;
218 }
219 
220 static void target_add_node_acl(struct se_node_acl *acl)
221 {
222 	struct se_portal_group *tpg = acl->se_tpg;
223 
224 	mutex_lock(&tpg->acl_node_mutex);
225 	list_add_tail(&acl->acl_list, &tpg->acl_node_list);
226 	mutex_unlock(&tpg->acl_node_mutex);
227 
228 	pr_debug("%s_TPG[%hu] - Added %s ACL with TCQ Depth: %d for %s"
229 		" Initiator Node: %s\n",
230 		tpg->se_tpg_tfo->get_fabric_name(),
231 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
232 		acl->dynamic_node_acl ? "DYNAMIC" : "",
233 		acl->queue_depth,
234 		tpg->se_tpg_tfo->get_fabric_name(),
235 		acl->initiatorname);
236 }
237 
238 bool target_tpg_has_node_acl(struct se_portal_group *tpg,
239 			     const char *initiatorname)
240 {
241 	struct se_node_acl *acl;
242 	bool found = false;
243 
244 	mutex_lock(&tpg->acl_node_mutex);
245 	list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
246 		if (!strcmp(acl->initiatorname, initiatorname)) {
247 			found = true;
248 			break;
249 		}
250 	}
251 	mutex_unlock(&tpg->acl_node_mutex);
252 
253 	return found;
254 }
255 EXPORT_SYMBOL(target_tpg_has_node_acl);
256 
257 struct se_node_acl *core_tpg_check_initiator_node_acl(
258 	struct se_portal_group *tpg,
259 	unsigned char *initiatorname)
260 {
261 	struct se_node_acl *acl;
262 
263 	acl = core_tpg_get_initiator_node_acl(tpg, initiatorname);
264 	if (acl)
265 		return acl;
266 
267 	if (!tpg->se_tpg_tfo->tpg_check_demo_mode(tpg))
268 		return NULL;
269 
270 	acl = target_alloc_node_acl(tpg, initiatorname);
271 	if (!acl)
272 		return NULL;
273 	/*
274 	 * When allocating a dynamically generated node_acl, go ahead
275 	 * and take the extra kref now before returning to the fabric
276 	 * driver caller.
277 	 *
278 	 * Note this reference will be released at session shutdown
279 	 * time within transport_free_session() code.
280 	 */
281 	kref_get(&acl->acl_kref);
282 	acl->dynamic_node_acl = 1;
283 
284 	/*
285 	 * Here we only create demo-mode MappedLUNs from the active
286 	 * TPG LUNs if the fabric is not explicitly asking for
287 	 * tpg_check_demo_mode_login_only() == 1.
288 	 */
289 	if ((tpg->se_tpg_tfo->tpg_check_demo_mode_login_only == NULL) ||
290 	    (tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg) != 1))
291 		core_tpg_add_node_to_devs(acl, tpg, NULL);
292 
293 	target_add_node_acl(acl);
294 	return acl;
295 }
296 EXPORT_SYMBOL(core_tpg_check_initiator_node_acl);
297 
298 void core_tpg_wait_for_nacl_pr_ref(struct se_node_acl *nacl)
299 {
300 	while (atomic_read(&nacl->acl_pr_ref_count) != 0)
301 		cpu_relax();
302 }
303 
304 struct se_node_acl *core_tpg_add_initiator_node_acl(
305 	struct se_portal_group *tpg,
306 	const char *initiatorname)
307 {
308 	struct se_node_acl *acl;
309 
310 	mutex_lock(&tpg->acl_node_mutex);
311 	acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
312 	if (acl) {
313 		if (acl->dynamic_node_acl) {
314 			acl->dynamic_node_acl = 0;
315 			pr_debug("%s_TPG[%u] - Replacing dynamic ACL"
316 				" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
317 				tpg->se_tpg_tfo->tpg_get_tag(tpg), initiatorname);
318 			mutex_unlock(&tpg->acl_node_mutex);
319 			return acl;
320 		}
321 
322 		pr_err("ACL entry for %s Initiator"
323 			" Node %s already exists for TPG %u, ignoring"
324 			" request.\n",  tpg->se_tpg_tfo->get_fabric_name(),
325 			initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
326 		mutex_unlock(&tpg->acl_node_mutex);
327 		return ERR_PTR(-EEXIST);
328 	}
329 	mutex_unlock(&tpg->acl_node_mutex);
330 
331 	acl = target_alloc_node_acl(tpg, initiatorname);
332 	if (!acl)
333 		return ERR_PTR(-ENOMEM);
334 
335 	target_add_node_acl(acl);
336 	return acl;
337 }
338 
339 static void target_shutdown_sessions(struct se_node_acl *acl)
340 {
341 	struct se_session *sess;
342 	unsigned long flags;
343 
344 restart:
345 	spin_lock_irqsave(&acl->nacl_sess_lock, flags);
346 	list_for_each_entry(sess, &acl->acl_sess_list, sess_acl_list) {
347 		if (sess->sess_tearing_down)
348 			continue;
349 
350 		list_del_init(&sess->sess_acl_list);
351 		spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
352 
353 		if (acl->se_tpg->se_tpg_tfo->close_session)
354 			acl->se_tpg->se_tpg_tfo->close_session(sess);
355 		goto restart;
356 	}
357 	spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
358 }
359 
360 void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
361 {
362 	struct se_portal_group *tpg = acl->se_tpg;
363 
364 	mutex_lock(&tpg->acl_node_mutex);
365 	if (acl->dynamic_node_acl)
366 		acl->dynamic_node_acl = 0;
367 	list_del(&acl->acl_list);
368 	mutex_unlock(&tpg->acl_node_mutex);
369 
370 	target_shutdown_sessions(acl);
371 
372 	target_put_nacl(acl);
373 	/*
374 	 * Wait for last target_put_nacl() to complete in target_complete_nacl()
375 	 * for active fabric session transport_deregister_session() callbacks.
376 	 */
377 	wait_for_completion(&acl->acl_free_comp);
378 
379 	core_tpg_wait_for_nacl_pr_ref(acl);
380 	core_free_device_list_for_node(acl, tpg);
381 
382 	pr_debug("%s_TPG[%hu] - Deleted ACL with TCQ Depth: %d for %s"
383 		" Initiator Node: %s\n", tpg->se_tpg_tfo->get_fabric_name(),
384 		tpg->se_tpg_tfo->tpg_get_tag(tpg), acl->queue_depth,
385 		tpg->se_tpg_tfo->get_fabric_name(), acl->initiatorname);
386 
387 	kfree(acl);
388 }
389 
390 /*	core_tpg_set_initiator_node_queue_depth():
391  *
392  *
393  */
394 int core_tpg_set_initiator_node_queue_depth(
395 	struct se_node_acl *acl,
396 	u32 queue_depth)
397 {
398 	struct se_portal_group *tpg = acl->se_tpg;
399 
400 	/*
401 	 * User has requested to change the queue depth for a Initiator Node.
402 	 * Change the value in the Node's struct se_node_acl, and call
403 	 * target_set_nacl_queue_depth() to set the new queue depth.
404 	 */
405 	target_set_nacl_queue_depth(tpg, acl, queue_depth);
406 
407 	/*
408 	 * Shutdown all pending sessions to force session reinstatement.
409 	 */
410 	target_shutdown_sessions(acl);
411 
412 	pr_debug("Successfully changed queue depth to: %d for Initiator"
413 		" Node: %s on %s Target Portal Group: %u\n", acl->queue_depth,
414 		acl->initiatorname, tpg->se_tpg_tfo->get_fabric_name(),
415 		tpg->se_tpg_tfo->tpg_get_tag(tpg));
416 
417 	return 0;
418 }
419 EXPORT_SYMBOL(core_tpg_set_initiator_node_queue_depth);
420 
421 /*	core_tpg_set_initiator_node_tag():
422  *
423  *	Initiator nodeacl tags are not used internally, but may be used by
424  *	userspace to emulate aliases or groups.
425  *	Returns length of newly-set tag or -EINVAL.
426  */
427 int core_tpg_set_initiator_node_tag(
428 	struct se_portal_group *tpg,
429 	struct se_node_acl *acl,
430 	const char *new_tag)
431 {
432 	if (strlen(new_tag) >= MAX_ACL_TAG_SIZE)
433 		return -EINVAL;
434 
435 	if (!strncmp("NULL", new_tag, 4)) {
436 		acl->acl_tag[0] = '\0';
437 		return 0;
438 	}
439 
440 	return snprintf(acl->acl_tag, MAX_ACL_TAG_SIZE, "%s", new_tag);
441 }
442 EXPORT_SYMBOL(core_tpg_set_initiator_node_tag);
443 
444 static void core_tpg_lun_ref_release(struct percpu_ref *ref)
445 {
446 	struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
447 
448 	complete(&lun->lun_ref_comp);
449 }
450 
451 int core_tpg_register(
452 	struct se_wwn *se_wwn,
453 	struct se_portal_group *se_tpg,
454 	int proto_id)
455 {
456 	int ret;
457 
458 	if (!se_tpg)
459 		return -EINVAL;
460 	/*
461 	 * For the typical case where core_tpg_register() is called by a
462 	 * fabric driver from target_core_fabric_ops->fabric_make_tpg()
463 	 * configfs context, use the original tf_ops pointer already saved
464 	 * by target-core in target_fabric_make_wwn().
465 	 *
466 	 * Otherwise, for special cases like iscsi-target discovery TPGs
467 	 * the caller is responsible for setting ->se_tpg_tfo ahead of
468 	 * calling core_tpg_register().
469 	 */
470 	if (se_wwn)
471 		se_tpg->se_tpg_tfo = se_wwn->wwn_tf->tf_ops;
472 
473 	if (!se_tpg->se_tpg_tfo) {
474 		pr_err("Unable to locate se_tpg->se_tpg_tfo pointer\n");
475 		return -EINVAL;
476 	}
477 
478 	INIT_HLIST_HEAD(&se_tpg->tpg_lun_hlist);
479 	se_tpg->proto_id = proto_id;
480 	se_tpg->se_tpg_wwn = se_wwn;
481 	atomic_set(&se_tpg->tpg_pr_ref_count, 0);
482 	INIT_LIST_HEAD(&se_tpg->acl_node_list);
483 	INIT_LIST_HEAD(&se_tpg->se_tpg_node);
484 	INIT_LIST_HEAD(&se_tpg->tpg_sess_list);
485 	spin_lock_init(&se_tpg->session_lock);
486 	mutex_init(&se_tpg->tpg_lun_mutex);
487 	mutex_init(&se_tpg->acl_node_mutex);
488 
489 	if (se_tpg->proto_id >= 0) {
490 		se_tpg->tpg_virt_lun0 = core_tpg_alloc_lun(se_tpg, 0);
491 		if (IS_ERR(se_tpg->tpg_virt_lun0))
492 			return PTR_ERR(se_tpg->tpg_virt_lun0);
493 
494 		ret = core_tpg_add_lun(se_tpg, se_tpg->tpg_virt_lun0,
495 				true, g_lun0_dev);
496 		if (ret < 0) {
497 			kfree(se_tpg->tpg_virt_lun0);
498 			return ret;
499 		}
500 	}
501 
502 	spin_lock_bh(&tpg_lock);
503 	list_add_tail(&se_tpg->se_tpg_node, &tpg_list);
504 	spin_unlock_bh(&tpg_lock);
505 
506 	pr_debug("TARGET_CORE[%s]: Allocated portal_group for endpoint: %s, "
507 		 "Proto: %d, Portal Tag: %u\n", se_tpg->se_tpg_tfo->get_fabric_name(),
508 		se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) ?
509 		se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) : NULL,
510 		se_tpg->proto_id, se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
511 
512 	return 0;
513 }
514 EXPORT_SYMBOL(core_tpg_register);
515 
516 int core_tpg_deregister(struct se_portal_group *se_tpg)
517 {
518 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
519 	struct se_node_acl *nacl, *nacl_tmp;
520 	LIST_HEAD(node_list);
521 
522 	pr_debug("TARGET_CORE[%s]: Deallocating portal_group for endpoint: %s, "
523 		 "Proto: %d, Portal Tag: %u\n", tfo->get_fabric_name(),
524 		tfo->tpg_get_wwn(se_tpg) ? tfo->tpg_get_wwn(se_tpg) : NULL,
525 		se_tpg->proto_id, tfo->tpg_get_tag(se_tpg));
526 
527 	spin_lock_bh(&tpg_lock);
528 	list_del(&se_tpg->se_tpg_node);
529 	spin_unlock_bh(&tpg_lock);
530 
531 	while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
532 		cpu_relax();
533 
534 	mutex_lock(&se_tpg->acl_node_mutex);
535 	list_splice_init(&se_tpg->acl_node_list, &node_list);
536 	mutex_unlock(&se_tpg->acl_node_mutex);
537 	/*
538 	 * Release any remaining demo-mode generated se_node_acl that have
539 	 * not been released because of TFO->tpg_check_demo_mode_cache() == 1
540 	 * in transport_deregister_session().
541 	 */
542 	list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) {
543 		list_del(&nacl->acl_list);
544 
545 		core_tpg_wait_for_nacl_pr_ref(nacl);
546 		core_free_device_list_for_node(nacl, se_tpg);
547 		kfree(nacl);
548 	}
549 
550 	if (se_tpg->proto_id >= 0) {
551 		core_tpg_remove_lun(se_tpg, se_tpg->tpg_virt_lun0);
552 		kfree_rcu(se_tpg->tpg_virt_lun0, rcu_head);
553 	}
554 
555 	return 0;
556 }
557 EXPORT_SYMBOL(core_tpg_deregister);
558 
559 struct se_lun *core_tpg_alloc_lun(
560 	struct se_portal_group *tpg,
561 	u64 unpacked_lun)
562 {
563 	struct se_lun *lun;
564 
565 	lun = kzalloc(sizeof(*lun), GFP_KERNEL);
566 	if (!lun) {
567 		pr_err("Unable to allocate se_lun memory\n");
568 		return ERR_PTR(-ENOMEM);
569 	}
570 	lun->unpacked_lun = unpacked_lun;
571 	lun->lun_link_magic = SE_LUN_LINK_MAGIC;
572 	atomic_set(&lun->lun_acl_count, 0);
573 	init_completion(&lun->lun_ref_comp);
574 	INIT_LIST_HEAD(&lun->lun_deve_list);
575 	INIT_LIST_HEAD(&lun->lun_dev_link);
576 	atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
577 	spin_lock_init(&lun->lun_deve_lock);
578 	mutex_init(&lun->lun_tg_pt_md_mutex);
579 	INIT_LIST_HEAD(&lun->lun_tg_pt_gp_link);
580 	spin_lock_init(&lun->lun_tg_pt_gp_lock);
581 	lun->lun_tpg = tpg;
582 
583 	return lun;
584 }
585 
586 int core_tpg_add_lun(
587 	struct se_portal_group *tpg,
588 	struct se_lun *lun,
589 	bool lun_access_ro,
590 	struct se_device *dev)
591 {
592 	int ret;
593 
594 	ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release, 0,
595 			      GFP_KERNEL);
596 	if (ret < 0)
597 		goto out;
598 
599 	ret = core_alloc_rtpi(lun, dev);
600 	if (ret)
601 		goto out_kill_ref;
602 
603 	if (!(dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH) &&
604 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
605 		target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);
606 
607 	mutex_lock(&tpg->tpg_lun_mutex);
608 
609 	spin_lock(&dev->se_port_lock);
610 	lun->lun_index = dev->dev_index;
611 	rcu_assign_pointer(lun->lun_se_dev, dev);
612 	dev->export_count++;
613 	list_add_tail(&lun->lun_dev_link, &dev->dev_sep_list);
614 	spin_unlock(&dev->se_port_lock);
615 
616 	if (dev->dev_flags & DF_READ_ONLY)
617 		lun->lun_access_ro = true;
618 	else
619 		lun->lun_access_ro = lun_access_ro;
620 	if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
621 		hlist_add_head_rcu(&lun->link, &tpg->tpg_lun_hlist);
622 	mutex_unlock(&tpg->tpg_lun_mutex);
623 
624 	return 0;
625 
626 out_kill_ref:
627 	percpu_ref_exit(&lun->lun_ref);
628 out:
629 	return ret;
630 }
631 
632 void core_tpg_remove_lun(
633 	struct se_portal_group *tpg,
634 	struct se_lun *lun)
635 {
636 	/*
637 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
638 	 * reference to se_device->dev_group.
639 	 */
640 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
641 
642 	core_clear_lun_from_tpg(lun, tpg);
643 	/*
644 	 * Wait for any active I/O references to percpu se_lun->lun_ref to
645 	 * be released.  Also, se_lun->lun_ref is now used by PR and ALUA
646 	 * logic when referencing a remote target port during ALL_TGT_PT=1
647 	 * and generating UNIT_ATTENTIONs for ALUA access state transition.
648 	 */
649 	transport_clear_lun_ref(lun);
650 
651 	mutex_lock(&tpg->tpg_lun_mutex);
652 	if (lun->lun_se_dev) {
653 		target_detach_tg_pt_gp(lun);
654 
655 		spin_lock(&dev->se_port_lock);
656 		list_del(&lun->lun_dev_link);
657 		dev->export_count--;
658 		rcu_assign_pointer(lun->lun_se_dev, NULL);
659 		spin_unlock(&dev->se_port_lock);
660 	}
661 	if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
662 		hlist_del_rcu(&lun->link);
663 	mutex_unlock(&tpg->tpg_lun_mutex);
664 
665 	percpu_ref_exit(&lun->lun_ref);
666 }
667