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 	mutex_lock(&tpg->acl_node_mutex);
80 	acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
81 	mutex_unlock(&tpg->acl_node_mutex);
82 
83 	return acl;
84 }
85 EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);
86 
87 void core_allocate_nexus_loss_ua(
88 	struct se_node_acl *nacl)
89 {
90 	struct se_dev_entry *deve;
91 
92 	if (!nacl)
93 		return;
94 
95 	rcu_read_lock();
96 	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link)
97 		core_scsi3_ua_allocate(deve, 0x29,
98 			ASCQ_29H_NEXUS_LOSS_OCCURRED);
99 	rcu_read_unlock();
100 }
101 EXPORT_SYMBOL(core_allocate_nexus_loss_ua);
102 
103 /*	core_tpg_add_node_to_devs():
104  *
105  *
106  */
107 void core_tpg_add_node_to_devs(
108 	struct se_node_acl *acl,
109 	struct se_portal_group *tpg,
110 	struct se_lun *lun_orig)
111 {
112 	u32 lun_access = 0;
113 	struct se_lun *lun;
114 	struct se_device *dev;
115 
116 	mutex_lock(&tpg->tpg_lun_mutex);
117 	hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link) {
118 		if (lun_orig && lun != lun_orig)
119 			continue;
120 
121 		dev = rcu_dereference_check(lun->lun_se_dev,
122 					    lockdep_is_held(&tpg->tpg_lun_mutex));
123 		/*
124 		 * By default in LIO-Target $FABRIC_MOD,
125 		 * demo_mode_write_protect is ON, or READ_ONLY;
126 		 */
127 		if (!tpg->se_tpg_tfo->tpg_check_demo_mode_write_protect(tpg)) {
128 			lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;
129 		} else {
130 			/*
131 			 * Allow only optical drives to issue R/W in default RO
132 			 * demo mode.
133 			 */
134 			if (dev->transport->get_device_type(dev) == TYPE_DISK)
135 				lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;
136 			else
137 				lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;
138 		}
139 
140 		pr_debug("TARGET_CORE[%s]->TPG[%u]_LUN[%llu] - Adding %s"
141 			" access for LUN in Demo Mode\n",
142 			tpg->se_tpg_tfo->get_fabric_name(),
143 			tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
144 			(lun_access == TRANSPORT_LUNFLAGS_READ_WRITE) ?
145 			"READ-WRITE" : "READ-ONLY");
146 
147 		core_enable_device_list_for_node(lun, NULL, lun->unpacked_lun,
148 						 lun_access, acl, tpg);
149 		/*
150 		 * Check to see if there are any existing persistent reservation
151 		 * APTPL pre-registrations that need to be enabled for this dynamic
152 		 * LUN ACL now..
153 		 */
154 		core_scsi3_check_aptpl_registration(dev, tpg, lun, acl,
155 						    lun->unpacked_lun);
156 	}
157 	mutex_unlock(&tpg->tpg_lun_mutex);
158 }
159 
160 /*      core_set_queue_depth_for_node():
161  *
162  *
163  */
164 static int core_set_queue_depth_for_node(
165 	struct se_portal_group *tpg,
166 	struct se_node_acl *acl)
167 {
168 	if (!acl->queue_depth) {
169 		pr_err("Queue depth for %s Initiator Node: %s is 0,"
170 			"defaulting to 1.\n", tpg->se_tpg_tfo->get_fabric_name(),
171 			acl->initiatorname);
172 		acl->queue_depth = 1;
173 	}
174 
175 	return 0;
176 }
177 
178 static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg,
179 		const unsigned char *initiatorname)
180 {
181 	struct se_node_acl *acl;
182 
183 	acl = kzalloc(max(sizeof(*acl), tpg->se_tpg_tfo->node_acl_size),
184 			GFP_KERNEL);
185 	if (!acl)
186 		return NULL;
187 
188 	INIT_LIST_HEAD(&acl->acl_list);
189 	INIT_LIST_HEAD(&acl->acl_sess_list);
190 	INIT_HLIST_HEAD(&acl->lun_entry_hlist);
191 	kref_init(&acl->acl_kref);
192 	init_completion(&acl->acl_free_comp);
193 	spin_lock_init(&acl->nacl_sess_lock);
194 	mutex_init(&acl->lun_entry_mutex);
195 	atomic_set(&acl->acl_pr_ref_count, 0);
196 	if (tpg->se_tpg_tfo->tpg_get_default_depth)
197 		acl->queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
198 	else
199 		acl->queue_depth = 1;
200 	snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
201 	acl->se_tpg = tpg;
202 	acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
203 
204 	tpg->se_tpg_tfo->set_default_node_attributes(acl);
205 
206 	if (core_set_queue_depth_for_node(tpg, acl) < 0)
207 		goto out_free_acl;
208 
209 	return acl;
210 
211 out_free_acl:
212 	kfree(acl);
213 	return NULL;
214 }
215 
216 static void target_add_node_acl(struct se_node_acl *acl)
217 {
218 	struct se_portal_group *tpg = acl->se_tpg;
219 
220 	mutex_lock(&tpg->acl_node_mutex);
221 	list_add_tail(&acl->acl_list, &tpg->acl_node_list);
222 	mutex_unlock(&tpg->acl_node_mutex);
223 
224 	pr_debug("%s_TPG[%hu] - Added %s ACL with TCQ Depth: %d for %s"
225 		" Initiator Node: %s\n",
226 		tpg->se_tpg_tfo->get_fabric_name(),
227 		tpg->se_tpg_tfo->tpg_get_tag(tpg),
228 		acl->dynamic_node_acl ? "DYNAMIC" : "",
229 		acl->queue_depth,
230 		tpg->se_tpg_tfo->get_fabric_name(),
231 		acl->initiatorname);
232 }
233 
234 struct se_node_acl *core_tpg_check_initiator_node_acl(
235 	struct se_portal_group *tpg,
236 	unsigned char *initiatorname)
237 {
238 	struct se_node_acl *acl;
239 
240 	acl = core_tpg_get_initiator_node_acl(tpg, initiatorname);
241 	if (acl)
242 		return acl;
243 
244 	if (!tpg->se_tpg_tfo->tpg_check_demo_mode(tpg))
245 		return NULL;
246 
247 	acl = target_alloc_node_acl(tpg, initiatorname);
248 	if (!acl)
249 		return NULL;
250 	acl->dynamic_node_acl = 1;
251 
252 	/*
253 	 * Here we only create demo-mode MappedLUNs from the active
254 	 * TPG LUNs if the fabric is not explicitly asking for
255 	 * tpg_check_demo_mode_login_only() == 1.
256 	 */
257 	if ((tpg->se_tpg_tfo->tpg_check_demo_mode_login_only == NULL) ||
258 	    (tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg) != 1))
259 		core_tpg_add_node_to_devs(acl, tpg, NULL);
260 
261 	target_add_node_acl(acl);
262 	return acl;
263 }
264 EXPORT_SYMBOL(core_tpg_check_initiator_node_acl);
265 
266 void core_tpg_wait_for_nacl_pr_ref(struct se_node_acl *nacl)
267 {
268 	while (atomic_read(&nacl->acl_pr_ref_count) != 0)
269 		cpu_relax();
270 }
271 
272 struct se_node_acl *core_tpg_add_initiator_node_acl(
273 	struct se_portal_group *tpg,
274 	const char *initiatorname)
275 {
276 	struct se_node_acl *acl;
277 
278 	mutex_lock(&tpg->acl_node_mutex);
279 	acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
280 	if (acl) {
281 		if (acl->dynamic_node_acl) {
282 			acl->dynamic_node_acl = 0;
283 			pr_debug("%s_TPG[%u] - Replacing dynamic ACL"
284 				" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
285 				tpg->se_tpg_tfo->tpg_get_tag(tpg), initiatorname);
286 			mutex_unlock(&tpg->acl_node_mutex);
287 			return acl;
288 		}
289 
290 		pr_err("ACL entry for %s Initiator"
291 			" Node %s already exists for TPG %u, ignoring"
292 			" request.\n",  tpg->se_tpg_tfo->get_fabric_name(),
293 			initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
294 		mutex_unlock(&tpg->acl_node_mutex);
295 		return ERR_PTR(-EEXIST);
296 	}
297 	mutex_unlock(&tpg->acl_node_mutex);
298 
299 	acl = target_alloc_node_acl(tpg, initiatorname);
300 	if (!acl)
301 		return ERR_PTR(-ENOMEM);
302 
303 	target_add_node_acl(acl);
304 	return acl;
305 }
306 
307 void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
308 {
309 	struct se_portal_group *tpg = acl->se_tpg;
310 	LIST_HEAD(sess_list);
311 	struct se_session *sess, *sess_tmp;
312 	unsigned long flags;
313 	int rc;
314 
315 	mutex_lock(&tpg->acl_node_mutex);
316 	if (acl->dynamic_node_acl) {
317 		acl->dynamic_node_acl = 0;
318 	}
319 	list_del(&acl->acl_list);
320 	mutex_unlock(&tpg->acl_node_mutex);
321 
322 	spin_lock_irqsave(&acl->nacl_sess_lock, flags);
323 	acl->acl_stop = 1;
324 
325 	list_for_each_entry_safe(sess, sess_tmp, &acl->acl_sess_list,
326 				sess_acl_list) {
327 		if (sess->sess_tearing_down != 0)
328 			continue;
329 
330 		target_get_session(sess);
331 		list_move(&sess->sess_acl_list, &sess_list);
332 	}
333 	spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
334 
335 	list_for_each_entry_safe(sess, sess_tmp, &sess_list, sess_acl_list) {
336 		list_del(&sess->sess_acl_list);
337 
338 		rc = tpg->se_tpg_tfo->shutdown_session(sess);
339 		target_put_session(sess);
340 		if (!rc)
341 			continue;
342 		target_put_session(sess);
343 	}
344 	target_put_nacl(acl);
345 	/*
346 	 * Wait for last target_put_nacl() to complete in target_complete_nacl()
347 	 * for active fabric session transport_deregister_session() callbacks.
348 	 */
349 	wait_for_completion(&acl->acl_free_comp);
350 
351 	core_tpg_wait_for_nacl_pr_ref(acl);
352 	core_free_device_list_for_node(acl, tpg);
353 
354 	pr_debug("%s_TPG[%hu] - Deleted ACL with TCQ Depth: %d for %s"
355 		" Initiator Node: %s\n", tpg->se_tpg_tfo->get_fabric_name(),
356 		tpg->se_tpg_tfo->tpg_get_tag(tpg), acl->queue_depth,
357 		tpg->se_tpg_tfo->get_fabric_name(), acl->initiatorname);
358 
359 	kfree(acl);
360 }
361 
362 /*	core_tpg_set_initiator_node_queue_depth():
363  *
364  *
365  */
366 int core_tpg_set_initiator_node_queue_depth(
367 	struct se_portal_group *tpg,
368 	unsigned char *initiatorname,
369 	u32 queue_depth,
370 	int force)
371 {
372 	struct se_session *sess, *init_sess = NULL;
373 	struct se_node_acl *acl;
374 	unsigned long flags;
375 	int dynamic_acl = 0;
376 
377 	mutex_lock(&tpg->acl_node_mutex);
378 	acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
379 	if (!acl) {
380 		pr_err("Access Control List entry for %s Initiator"
381 			" Node %s does not exists for TPG %hu, ignoring"
382 			" request.\n", tpg->se_tpg_tfo->get_fabric_name(),
383 			initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
384 		mutex_unlock(&tpg->acl_node_mutex);
385 		return -ENODEV;
386 	}
387 	if (acl->dynamic_node_acl) {
388 		acl->dynamic_node_acl = 0;
389 		dynamic_acl = 1;
390 	}
391 	mutex_unlock(&tpg->acl_node_mutex);
392 
393 	spin_lock_irqsave(&tpg->session_lock, flags);
394 	list_for_each_entry(sess, &tpg->tpg_sess_list, sess_list) {
395 		if (sess->se_node_acl != acl)
396 			continue;
397 
398 		if (!force) {
399 			pr_err("Unable to change queue depth for %s"
400 				" Initiator Node: %s while session is"
401 				" operational.  To forcefully change the queue"
402 				" depth and force session reinstatement"
403 				" use the \"force=1\" parameter.\n",
404 				tpg->se_tpg_tfo->get_fabric_name(), initiatorname);
405 			spin_unlock_irqrestore(&tpg->session_lock, flags);
406 
407 			mutex_lock(&tpg->acl_node_mutex);
408 			if (dynamic_acl)
409 				acl->dynamic_node_acl = 1;
410 			mutex_unlock(&tpg->acl_node_mutex);
411 			return -EEXIST;
412 		}
413 		/*
414 		 * Determine if the session needs to be closed by our context.
415 		 */
416 		if (!tpg->se_tpg_tfo->shutdown_session(sess))
417 			continue;
418 
419 		init_sess = sess;
420 		break;
421 	}
422 
423 	/*
424 	 * User has requested to change the queue depth for a Initiator Node.
425 	 * Change the value in the Node's struct se_node_acl, and call
426 	 * core_set_queue_depth_for_node() to add the requested queue depth.
427 	 *
428 	 * Finally call  tpg->se_tpg_tfo->close_session() to force session
429 	 * reinstatement to occur if there is an active session for the
430 	 * $FABRIC_MOD Initiator Node in question.
431 	 */
432 	acl->queue_depth = queue_depth;
433 
434 	if (core_set_queue_depth_for_node(tpg, acl) < 0) {
435 		spin_unlock_irqrestore(&tpg->session_lock, flags);
436 		/*
437 		 * Force session reinstatement if
438 		 * core_set_queue_depth_for_node() failed, because we assume
439 		 * the $FABRIC_MOD has already the set session reinstatement
440 		 * bit from tpg->se_tpg_tfo->shutdown_session() called above.
441 		 */
442 		if (init_sess)
443 			tpg->se_tpg_tfo->close_session(init_sess);
444 
445 		mutex_lock(&tpg->acl_node_mutex);
446 		if (dynamic_acl)
447 			acl->dynamic_node_acl = 1;
448 		mutex_unlock(&tpg->acl_node_mutex);
449 		return -EINVAL;
450 	}
451 	spin_unlock_irqrestore(&tpg->session_lock, flags);
452 	/*
453 	 * If the $FABRIC_MOD session for the Initiator Node ACL exists,
454 	 * forcefully shutdown the $FABRIC_MOD session/nexus.
455 	 */
456 	if (init_sess)
457 		tpg->se_tpg_tfo->close_session(init_sess);
458 
459 	pr_debug("Successfully changed queue depth to: %d for Initiator"
460 		" Node: %s on %s Target Portal Group: %u\n", queue_depth,
461 		initiatorname, tpg->se_tpg_tfo->get_fabric_name(),
462 		tpg->se_tpg_tfo->tpg_get_tag(tpg));
463 
464 	mutex_lock(&tpg->acl_node_mutex);
465 	if (dynamic_acl)
466 		acl->dynamic_node_acl = 1;
467 	mutex_unlock(&tpg->acl_node_mutex);
468 
469 	return 0;
470 }
471 EXPORT_SYMBOL(core_tpg_set_initiator_node_queue_depth);
472 
473 /*	core_tpg_set_initiator_node_tag():
474  *
475  *	Initiator nodeacl tags are not used internally, but may be used by
476  *	userspace to emulate aliases or groups.
477  *	Returns length of newly-set tag or -EINVAL.
478  */
479 int core_tpg_set_initiator_node_tag(
480 	struct se_portal_group *tpg,
481 	struct se_node_acl *acl,
482 	const char *new_tag)
483 {
484 	if (strlen(new_tag) >= MAX_ACL_TAG_SIZE)
485 		return -EINVAL;
486 
487 	if (!strncmp("NULL", new_tag, 4)) {
488 		acl->acl_tag[0] = '\0';
489 		return 0;
490 	}
491 
492 	return snprintf(acl->acl_tag, MAX_ACL_TAG_SIZE, "%s", new_tag);
493 }
494 EXPORT_SYMBOL(core_tpg_set_initiator_node_tag);
495 
496 static void core_tpg_lun_ref_release(struct percpu_ref *ref)
497 {
498 	struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
499 
500 	complete(&lun->lun_ref_comp);
501 }
502 
503 int core_tpg_register(
504 	struct se_wwn *se_wwn,
505 	struct se_portal_group *se_tpg,
506 	int proto_id)
507 {
508 	int ret;
509 
510 	if (!se_tpg)
511 		return -EINVAL;
512 	/*
513 	 * For the typical case where core_tpg_register() is called by a
514 	 * fabric driver from target_core_fabric_ops->fabric_make_tpg()
515 	 * configfs context, use the original tf_ops pointer already saved
516 	 * by target-core in target_fabric_make_wwn().
517 	 *
518 	 * Otherwise, for special cases like iscsi-target discovery TPGs
519 	 * the caller is responsible for setting ->se_tpg_tfo ahead of
520 	 * calling core_tpg_register().
521 	 */
522 	if (se_wwn)
523 		se_tpg->se_tpg_tfo = se_wwn->wwn_tf->tf_ops;
524 
525 	if (!se_tpg->se_tpg_tfo) {
526 		pr_err("Unable to locate se_tpg->se_tpg_tfo pointer\n");
527 		return -EINVAL;
528 	}
529 
530 	INIT_HLIST_HEAD(&se_tpg->tpg_lun_hlist);
531 	se_tpg->proto_id = proto_id;
532 	se_tpg->se_tpg_wwn = se_wwn;
533 	atomic_set(&se_tpg->tpg_pr_ref_count, 0);
534 	INIT_LIST_HEAD(&se_tpg->acl_node_list);
535 	INIT_LIST_HEAD(&se_tpg->se_tpg_node);
536 	INIT_LIST_HEAD(&se_tpg->tpg_sess_list);
537 	spin_lock_init(&se_tpg->session_lock);
538 	mutex_init(&se_tpg->tpg_lun_mutex);
539 	mutex_init(&se_tpg->acl_node_mutex);
540 
541 	if (se_tpg->proto_id >= 0) {
542 		se_tpg->tpg_virt_lun0 = core_tpg_alloc_lun(se_tpg, 0);
543 		if (IS_ERR(se_tpg->tpg_virt_lun0))
544 			return PTR_ERR(se_tpg->tpg_virt_lun0);
545 
546 		ret = core_tpg_add_lun(se_tpg, se_tpg->tpg_virt_lun0,
547 				TRANSPORT_LUNFLAGS_READ_ONLY, g_lun0_dev);
548 		if (ret < 0) {
549 			kfree(se_tpg->tpg_virt_lun0);
550 			return ret;
551 		}
552 	}
553 
554 	spin_lock_bh(&tpg_lock);
555 	list_add_tail(&se_tpg->se_tpg_node, &tpg_list);
556 	spin_unlock_bh(&tpg_lock);
557 
558 	pr_debug("TARGET_CORE[%s]: Allocated portal_group for endpoint: %s, "
559 		 "Proto: %d, Portal Tag: %u\n", se_tpg->se_tpg_tfo->get_fabric_name(),
560 		se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) ?
561 		se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) : NULL,
562 		se_tpg->proto_id, se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
563 
564 	return 0;
565 }
566 EXPORT_SYMBOL(core_tpg_register);
567 
568 int core_tpg_deregister(struct se_portal_group *se_tpg)
569 {
570 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
571 	struct se_node_acl *nacl, *nacl_tmp;
572 	LIST_HEAD(node_list);
573 
574 	pr_debug("TARGET_CORE[%s]: Deallocating portal_group for endpoint: %s, "
575 		 "Proto: %d, Portal Tag: %u\n", tfo->get_fabric_name(),
576 		tfo->tpg_get_wwn(se_tpg) ? tfo->tpg_get_wwn(se_tpg) : NULL,
577 		se_tpg->proto_id, tfo->tpg_get_tag(se_tpg));
578 
579 	spin_lock_bh(&tpg_lock);
580 	list_del(&se_tpg->se_tpg_node);
581 	spin_unlock_bh(&tpg_lock);
582 
583 	while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
584 		cpu_relax();
585 
586 	mutex_lock(&se_tpg->acl_node_mutex);
587 	list_splice_init(&se_tpg->acl_node_list, &node_list);
588 	mutex_unlock(&se_tpg->acl_node_mutex);
589 	/*
590 	 * Release any remaining demo-mode generated se_node_acl that have
591 	 * not been released because of TFO->tpg_check_demo_mode_cache() == 1
592 	 * in transport_deregister_session().
593 	 */
594 	list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) {
595 		list_del(&nacl->acl_list);
596 
597 		core_tpg_wait_for_nacl_pr_ref(nacl);
598 		core_free_device_list_for_node(nacl, se_tpg);
599 		kfree(nacl);
600 	}
601 
602 	if (se_tpg->proto_id >= 0) {
603 		core_tpg_remove_lun(se_tpg, se_tpg->tpg_virt_lun0);
604 		kfree_rcu(se_tpg->tpg_virt_lun0, rcu_head);
605 	}
606 
607 	return 0;
608 }
609 EXPORT_SYMBOL(core_tpg_deregister);
610 
611 struct se_lun *core_tpg_alloc_lun(
612 	struct se_portal_group *tpg,
613 	u64 unpacked_lun)
614 {
615 	struct se_lun *lun;
616 
617 	lun = kzalloc(sizeof(*lun), GFP_KERNEL);
618 	if (!lun) {
619 		pr_err("Unable to allocate se_lun memory\n");
620 		return ERR_PTR(-ENOMEM);
621 	}
622 	lun->unpacked_lun = unpacked_lun;
623 	lun->lun_link_magic = SE_LUN_LINK_MAGIC;
624 	atomic_set(&lun->lun_acl_count, 0);
625 	init_completion(&lun->lun_ref_comp);
626 	INIT_LIST_HEAD(&lun->lun_deve_list);
627 	INIT_LIST_HEAD(&lun->lun_dev_link);
628 	atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
629 	spin_lock_init(&lun->lun_deve_lock);
630 	mutex_init(&lun->lun_tg_pt_md_mutex);
631 	INIT_LIST_HEAD(&lun->lun_tg_pt_gp_link);
632 	spin_lock_init(&lun->lun_tg_pt_gp_lock);
633 	lun->lun_tpg = tpg;
634 
635 	return lun;
636 }
637 
638 int core_tpg_add_lun(
639 	struct se_portal_group *tpg,
640 	struct se_lun *lun,
641 	u32 lun_access,
642 	struct se_device *dev)
643 {
644 	int ret;
645 
646 	ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release, 0,
647 			      GFP_KERNEL);
648 	if (ret < 0)
649 		goto out;
650 
651 	ret = core_alloc_rtpi(lun, dev);
652 	if (ret)
653 		goto out_kill_ref;
654 
655 	if (!(dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH) &&
656 	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
657 		target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);
658 
659 	mutex_lock(&tpg->tpg_lun_mutex);
660 
661 	spin_lock(&dev->se_port_lock);
662 	lun->lun_index = dev->dev_index;
663 	rcu_assign_pointer(lun->lun_se_dev, dev);
664 	dev->export_count++;
665 	list_add_tail(&lun->lun_dev_link, &dev->dev_sep_list);
666 	spin_unlock(&dev->se_port_lock);
667 
668 	if (dev->dev_flags & DF_READ_ONLY)
669 		lun->lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;
670 	else
671 		lun->lun_access = lun_access;
672 	if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
673 		hlist_add_head_rcu(&lun->link, &tpg->tpg_lun_hlist);
674 	mutex_unlock(&tpg->tpg_lun_mutex);
675 
676 	return 0;
677 
678 out_kill_ref:
679 	percpu_ref_exit(&lun->lun_ref);
680 out:
681 	return ret;
682 }
683 
684 void core_tpg_remove_lun(
685 	struct se_portal_group *tpg,
686 	struct se_lun *lun)
687 {
688 	/*
689 	 * rcu_dereference_raw protected by se_lun->lun_group symlink
690 	 * reference to se_device->dev_group.
691 	 */
692 	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
693 
694 	core_clear_lun_from_tpg(lun, tpg);
695 	/*
696 	 * Wait for any active I/O references to percpu se_lun->lun_ref to
697 	 * be released.  Also, se_lun->lun_ref is now used by PR and ALUA
698 	 * logic when referencing a remote target port during ALL_TGT_PT=1
699 	 * and generating UNIT_ATTENTIONs for ALUA access state transition.
700 	 */
701 	transport_clear_lun_ref(lun);
702 
703 	mutex_lock(&tpg->tpg_lun_mutex);
704 	if (lun->lun_se_dev) {
705 		target_detach_tg_pt_gp(lun);
706 
707 		spin_lock(&dev->se_port_lock);
708 		list_del(&lun->lun_dev_link);
709 		dev->export_count--;
710 		rcu_assign_pointer(lun->lun_se_dev, NULL);
711 		spin_unlock(&dev->se_port_lock);
712 	}
713 	if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
714 		hlist_del_rcu(&lun->link);
715 	mutex_unlock(&tpg->tpg_lun_mutex);
716 
717 	percpu_ref_exit(&lun->lun_ref);
718 }
719