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
46extern struct se_device *g_lun0_dev;
47
48static DEFINE_SPINLOCK(tpg_lock);
49static 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 */
55struct 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 */
73struct 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}
85EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);
86
87void 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}
101EXPORT_SYMBOL(core_allocate_nexus_loss_ua);
102
103/*	core_tpg_add_node_to_devs():
104 *
105 *
106 */
107void 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 */
164static 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
178static 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
211out_free_acl:
212	kfree(acl);
213	return NULL;
214}
215
216static 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	tpg->num_node_acls++;
223	mutex_unlock(&tpg->acl_node_mutex);
224
225	pr_debug("%s_TPG[%hu] - Added %s ACL with TCQ Depth: %d for %s"
226		" Initiator Node: %s\n",
227		tpg->se_tpg_tfo->get_fabric_name(),
228		tpg->se_tpg_tfo->tpg_get_tag(tpg),
229		acl->dynamic_node_acl ? "DYNAMIC" : "",
230		acl->queue_depth,
231		tpg->se_tpg_tfo->get_fabric_name(),
232		acl->initiatorname);
233}
234
235struct se_node_acl *core_tpg_check_initiator_node_acl(
236	struct se_portal_group *tpg,
237	unsigned char *initiatorname)
238{
239	struct se_node_acl *acl;
240
241	acl = core_tpg_get_initiator_node_acl(tpg, initiatorname);
242	if (acl)
243		return acl;
244
245	if (!tpg->se_tpg_tfo->tpg_check_demo_mode(tpg))
246		return NULL;
247
248	acl = target_alloc_node_acl(tpg, initiatorname);
249	if (!acl)
250		return NULL;
251	acl->dynamic_node_acl = 1;
252
253	/*
254	 * Here we only create demo-mode MappedLUNs from the active
255	 * TPG LUNs if the fabric is not explicitly asking for
256	 * tpg_check_demo_mode_login_only() == 1.
257	 */
258	if ((tpg->se_tpg_tfo->tpg_check_demo_mode_login_only == NULL) ||
259	    (tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg) != 1))
260		core_tpg_add_node_to_devs(acl, tpg, NULL);
261
262	target_add_node_acl(acl);
263	return acl;
264}
265EXPORT_SYMBOL(core_tpg_check_initiator_node_acl);
266
267void core_tpg_wait_for_nacl_pr_ref(struct se_node_acl *nacl)
268{
269	while (atomic_read(&nacl->acl_pr_ref_count) != 0)
270		cpu_relax();
271}
272
273struct se_node_acl *core_tpg_add_initiator_node_acl(
274	struct se_portal_group *tpg,
275	const char *initiatorname)
276{
277	struct se_node_acl *acl;
278
279	mutex_lock(&tpg->acl_node_mutex);
280	acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
281	if (acl) {
282		if (acl->dynamic_node_acl) {
283			acl->dynamic_node_acl = 0;
284			pr_debug("%s_TPG[%u] - Replacing dynamic ACL"
285				" for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
286				tpg->se_tpg_tfo->tpg_get_tag(tpg), initiatorname);
287			mutex_unlock(&tpg->acl_node_mutex);
288			return acl;
289		}
290
291		pr_err("ACL entry for %s Initiator"
292			" Node %s already exists for TPG %u, ignoring"
293			" request.\n",  tpg->se_tpg_tfo->get_fabric_name(),
294			initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
295		mutex_unlock(&tpg->acl_node_mutex);
296		return ERR_PTR(-EEXIST);
297	}
298	mutex_unlock(&tpg->acl_node_mutex);
299
300	acl = target_alloc_node_acl(tpg, initiatorname);
301	if (!acl)
302		return ERR_PTR(-ENOMEM);
303
304	target_add_node_acl(acl);
305	return acl;
306}
307
308void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
309{
310	struct se_portal_group *tpg = acl->se_tpg;
311	LIST_HEAD(sess_list);
312	struct se_session *sess, *sess_tmp;
313	unsigned long flags;
314	int rc;
315
316	mutex_lock(&tpg->acl_node_mutex);
317	if (acl->dynamic_node_acl) {
318		acl->dynamic_node_acl = 0;
319	}
320	list_del(&acl->acl_list);
321	tpg->num_node_acls--;
322	mutex_unlock(&tpg->acl_node_mutex);
323
324	spin_lock_irqsave(&acl->nacl_sess_lock, flags);
325	acl->acl_stop = 1;
326
327	list_for_each_entry_safe(sess, sess_tmp, &acl->acl_sess_list,
328				sess_acl_list) {
329		if (sess->sess_tearing_down != 0)
330			continue;
331
332		target_get_session(sess);
333		list_move(&sess->sess_acl_list, &sess_list);
334	}
335	spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
336
337	list_for_each_entry_safe(sess, sess_tmp, &sess_list, sess_acl_list) {
338		list_del(&sess->sess_acl_list);
339
340		rc = tpg->se_tpg_tfo->shutdown_session(sess);
341		target_put_session(sess);
342		if (!rc)
343			continue;
344		target_put_session(sess);
345	}
346	target_put_nacl(acl);
347	/*
348	 * Wait for last target_put_nacl() to complete in target_complete_nacl()
349	 * for active fabric session transport_deregister_session() callbacks.
350	 */
351	wait_for_completion(&acl->acl_free_comp);
352
353	core_tpg_wait_for_nacl_pr_ref(acl);
354	core_free_device_list_for_node(acl, tpg);
355
356	pr_debug("%s_TPG[%hu] - Deleted ACL with TCQ Depth: %d for %s"
357		" Initiator Node: %s\n", tpg->se_tpg_tfo->get_fabric_name(),
358		tpg->se_tpg_tfo->tpg_get_tag(tpg), acl->queue_depth,
359		tpg->se_tpg_tfo->get_fabric_name(), acl->initiatorname);
360
361	kfree(acl);
362}
363
364/*	core_tpg_set_initiator_node_queue_depth():
365 *
366 *
367 */
368int core_tpg_set_initiator_node_queue_depth(
369	struct se_portal_group *tpg,
370	unsigned char *initiatorname,
371	u32 queue_depth,
372	int force)
373{
374	struct se_session *sess, *init_sess = NULL;
375	struct se_node_acl *acl;
376	unsigned long flags;
377	int dynamic_acl = 0;
378
379	mutex_lock(&tpg->acl_node_mutex);
380	acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
381	if (!acl) {
382		pr_err("Access Control List entry for %s Initiator"
383			" Node %s does not exists for TPG %hu, ignoring"
384			" request.\n", tpg->se_tpg_tfo->get_fabric_name(),
385			initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
386		mutex_unlock(&tpg->acl_node_mutex);
387		return -ENODEV;
388	}
389	if (acl->dynamic_node_acl) {
390		acl->dynamic_node_acl = 0;
391		dynamic_acl = 1;
392	}
393	mutex_unlock(&tpg->acl_node_mutex);
394
395	spin_lock_irqsave(&tpg->session_lock, flags);
396	list_for_each_entry(sess, &tpg->tpg_sess_list, sess_list) {
397		if (sess->se_node_acl != acl)
398			continue;
399
400		if (!force) {
401			pr_err("Unable to change queue depth for %s"
402				" Initiator Node: %s while session is"
403				" operational.  To forcefully change the queue"
404				" depth and force session reinstatement"
405				" use the \"force=1\" parameter.\n",
406				tpg->se_tpg_tfo->get_fabric_name(), initiatorname);
407			spin_unlock_irqrestore(&tpg->session_lock, flags);
408
409			mutex_lock(&tpg->acl_node_mutex);
410			if (dynamic_acl)
411				acl->dynamic_node_acl = 1;
412			mutex_unlock(&tpg->acl_node_mutex);
413			return -EEXIST;
414		}
415		/*
416		 * Determine if the session needs to be closed by our context.
417		 */
418		if (!tpg->se_tpg_tfo->shutdown_session(sess))
419			continue;
420
421		init_sess = sess;
422		break;
423	}
424
425	/*
426	 * User has requested to change the queue depth for a Initiator Node.
427	 * Change the value in the Node's struct se_node_acl, and call
428	 * core_set_queue_depth_for_node() to add the requested queue depth.
429	 *
430	 * Finally call  tpg->se_tpg_tfo->close_session() to force session
431	 * reinstatement to occur if there is an active session for the
432	 * $FABRIC_MOD Initiator Node in question.
433	 */
434	acl->queue_depth = queue_depth;
435
436	if (core_set_queue_depth_for_node(tpg, acl) < 0) {
437		spin_unlock_irqrestore(&tpg->session_lock, flags);
438		/*
439		 * Force session reinstatement if
440		 * core_set_queue_depth_for_node() failed, because we assume
441		 * the $FABRIC_MOD has already the set session reinstatement
442		 * bit from tpg->se_tpg_tfo->shutdown_session() called above.
443		 */
444		if (init_sess)
445			tpg->se_tpg_tfo->close_session(init_sess);
446
447		mutex_lock(&tpg->acl_node_mutex);
448		if (dynamic_acl)
449			acl->dynamic_node_acl = 1;
450		mutex_unlock(&tpg->acl_node_mutex);
451		return -EINVAL;
452	}
453	spin_unlock_irqrestore(&tpg->session_lock, flags);
454	/*
455	 * If the $FABRIC_MOD session for the Initiator Node ACL exists,
456	 * forcefully shutdown the $FABRIC_MOD session/nexus.
457	 */
458	if (init_sess)
459		tpg->se_tpg_tfo->close_session(init_sess);
460
461	pr_debug("Successfully changed queue depth to: %d for Initiator"
462		" Node: %s on %s Target Portal Group: %u\n", queue_depth,
463		initiatorname, tpg->se_tpg_tfo->get_fabric_name(),
464		tpg->se_tpg_tfo->tpg_get_tag(tpg));
465
466	mutex_lock(&tpg->acl_node_mutex);
467	if (dynamic_acl)
468		acl->dynamic_node_acl = 1;
469	mutex_unlock(&tpg->acl_node_mutex);
470
471	return 0;
472}
473EXPORT_SYMBOL(core_tpg_set_initiator_node_queue_depth);
474
475/*	core_tpg_set_initiator_node_tag():
476 *
477 *	Initiator nodeacl tags are not used internally, but may be used by
478 *	userspace to emulate aliases or groups.
479 *	Returns length of newly-set tag or -EINVAL.
480 */
481int core_tpg_set_initiator_node_tag(
482	struct se_portal_group *tpg,
483	struct se_node_acl *acl,
484	const char *new_tag)
485{
486	if (strlen(new_tag) >= MAX_ACL_TAG_SIZE)
487		return -EINVAL;
488
489	if (!strncmp("NULL", new_tag, 4)) {
490		acl->acl_tag[0] = '\0';
491		return 0;
492	}
493
494	return snprintf(acl->acl_tag, MAX_ACL_TAG_SIZE, "%s", new_tag);
495}
496EXPORT_SYMBOL(core_tpg_set_initiator_node_tag);
497
498static void core_tpg_lun_ref_release(struct percpu_ref *ref)
499{
500	struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
501
502	complete(&lun->lun_ref_comp);
503}
504
505int core_tpg_register(
506	struct se_wwn *se_wwn,
507	struct se_portal_group *se_tpg,
508	int proto_id)
509{
510	int ret;
511
512	if (!se_tpg)
513		return -EINVAL;
514	/*
515	 * For the typical case where core_tpg_register() is called by a
516	 * fabric driver from target_core_fabric_ops->fabric_make_tpg()
517	 * configfs context, use the original tf_ops pointer already saved
518	 * by target-core in target_fabric_make_wwn().
519	 *
520	 * Otherwise, for special cases like iscsi-target discovery TPGs
521	 * the caller is responsible for setting ->se_tpg_tfo ahead of
522	 * calling core_tpg_register().
523	 */
524	if (se_wwn)
525		se_tpg->se_tpg_tfo = se_wwn->wwn_tf->tf_ops;
526
527	if (!se_tpg->se_tpg_tfo) {
528		pr_err("Unable to locate se_tpg->se_tpg_tfo pointer\n");
529		return -EINVAL;
530	}
531
532	INIT_HLIST_HEAD(&se_tpg->tpg_lun_hlist);
533	se_tpg->proto_id = proto_id;
534	se_tpg->se_tpg_wwn = se_wwn;
535	atomic_set(&se_tpg->tpg_pr_ref_count, 0);
536	INIT_LIST_HEAD(&se_tpg->acl_node_list);
537	INIT_LIST_HEAD(&se_tpg->se_tpg_node);
538	INIT_LIST_HEAD(&se_tpg->tpg_sess_list);
539	spin_lock_init(&se_tpg->session_lock);
540	mutex_init(&se_tpg->tpg_lun_mutex);
541	mutex_init(&se_tpg->acl_node_mutex);
542
543	if (se_tpg->proto_id >= 0) {
544		se_tpg->tpg_virt_lun0 = core_tpg_alloc_lun(se_tpg, 0);
545		if (IS_ERR(se_tpg->tpg_virt_lun0))
546			return PTR_ERR(se_tpg->tpg_virt_lun0);
547
548		ret = core_tpg_add_lun(se_tpg, se_tpg->tpg_virt_lun0,
549				TRANSPORT_LUNFLAGS_READ_ONLY, g_lun0_dev);
550		if (ret < 0) {
551			kfree(se_tpg->tpg_virt_lun0);
552			return ret;
553		}
554	}
555
556	spin_lock_bh(&tpg_lock);
557	list_add_tail(&se_tpg->se_tpg_node, &tpg_list);
558	spin_unlock_bh(&tpg_lock);
559
560	pr_debug("TARGET_CORE[%s]: Allocated portal_group for endpoint: %s, "
561		 "Proto: %d, Portal Tag: %u\n", se_tpg->se_tpg_tfo->get_fabric_name(),
562		se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) ?
563		se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) : NULL,
564		se_tpg->proto_id, se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
565
566	return 0;
567}
568EXPORT_SYMBOL(core_tpg_register);
569
570int core_tpg_deregister(struct se_portal_group *se_tpg)
571{
572	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
573	struct se_node_acl *nacl, *nacl_tmp;
574	LIST_HEAD(node_list);
575
576	pr_debug("TARGET_CORE[%s]: Deallocating portal_group for endpoint: %s, "
577		 "Proto: %d, Portal Tag: %u\n", tfo->get_fabric_name(),
578		tfo->tpg_get_wwn(se_tpg) ? tfo->tpg_get_wwn(se_tpg) : NULL,
579		se_tpg->proto_id, tfo->tpg_get_tag(se_tpg));
580
581	spin_lock_bh(&tpg_lock);
582	list_del(&se_tpg->se_tpg_node);
583	spin_unlock_bh(&tpg_lock);
584
585	while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
586		cpu_relax();
587
588	mutex_lock(&se_tpg->acl_node_mutex);
589	list_splice_init(&se_tpg->acl_node_list, &node_list);
590	mutex_unlock(&se_tpg->acl_node_mutex);
591	/*
592	 * Release any remaining demo-mode generated se_node_acl that have
593	 * not been released because of TFO->tpg_check_demo_mode_cache() == 1
594	 * in transport_deregister_session().
595	 */
596	list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) {
597		list_del(&nacl->acl_list);
598		se_tpg->num_node_acls--;
599
600		core_tpg_wait_for_nacl_pr_ref(nacl);
601		core_free_device_list_for_node(nacl, se_tpg);
602		kfree(nacl);
603	}
604
605	if (se_tpg->proto_id >= 0) {
606		core_tpg_remove_lun(se_tpg, se_tpg->tpg_virt_lun0);
607		kfree_rcu(se_tpg->tpg_virt_lun0, rcu_head);
608	}
609
610	return 0;
611}
612EXPORT_SYMBOL(core_tpg_deregister);
613
614struct se_lun *core_tpg_alloc_lun(
615	struct se_portal_group *tpg,
616	u64 unpacked_lun)
617{
618	struct se_lun *lun;
619
620	lun = kzalloc(sizeof(*lun), GFP_KERNEL);
621	if (!lun) {
622		pr_err("Unable to allocate se_lun memory\n");
623		return ERR_PTR(-ENOMEM);
624	}
625	lun->unpacked_lun = unpacked_lun;
626	lun->lun_link_magic = SE_LUN_LINK_MAGIC;
627	atomic_set(&lun->lun_acl_count, 0);
628	init_completion(&lun->lun_ref_comp);
629	INIT_LIST_HEAD(&lun->lun_deve_list);
630	INIT_LIST_HEAD(&lun->lun_dev_link);
631	atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
632	spin_lock_init(&lun->lun_deve_lock);
633	mutex_init(&lun->lun_tg_pt_md_mutex);
634	INIT_LIST_HEAD(&lun->lun_tg_pt_gp_link);
635	spin_lock_init(&lun->lun_tg_pt_gp_lock);
636	lun->lun_tpg = tpg;
637
638	return lun;
639}
640
641int core_tpg_add_lun(
642	struct se_portal_group *tpg,
643	struct se_lun *lun,
644	u32 lun_access,
645	struct se_device *dev)
646{
647	int ret;
648
649	ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release, 0,
650			      GFP_KERNEL);
651	if (ret < 0)
652		goto out;
653
654	ret = core_alloc_rtpi(lun, dev);
655	if (ret)
656		goto out_kill_ref;
657
658	if (!(dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH) &&
659	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
660		target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);
661
662	mutex_lock(&tpg->tpg_lun_mutex);
663
664	spin_lock(&dev->se_port_lock);
665	lun->lun_index = dev->dev_index;
666	rcu_assign_pointer(lun->lun_se_dev, dev);
667	dev->export_count++;
668	list_add_tail(&lun->lun_dev_link, &dev->dev_sep_list);
669	spin_unlock(&dev->se_port_lock);
670
671	if (dev->dev_flags & DF_READ_ONLY)
672		lun->lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;
673	else
674		lun->lun_access = lun_access;
675	if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
676		hlist_add_head_rcu(&lun->link, &tpg->tpg_lun_hlist);
677	mutex_unlock(&tpg->tpg_lun_mutex);
678
679	return 0;
680
681out_kill_ref:
682	percpu_ref_exit(&lun->lun_ref);
683out:
684	return ret;
685}
686
687void core_tpg_remove_lun(
688	struct se_portal_group *tpg,
689	struct se_lun *lun)
690{
691	/*
692	 * rcu_dereference_raw protected by se_lun->lun_group symlink
693	 * reference to se_device->dev_group.
694	 */
695	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
696
697	core_clear_lun_from_tpg(lun, tpg);
698	/*
699	 * Wait for any active I/O references to percpu se_lun->lun_ref to
700	 * be released.  Also, se_lun->lun_ref is now used by PR and ALUA
701	 * logic when referencing a remote target port during ALL_TGT_PT=1
702	 * and generating UNIT_ATTENTIONs for ALUA access state transition.
703	 */
704	transport_clear_lun_ref(lun);
705
706	mutex_lock(&tpg->tpg_lun_mutex);
707	if (lun->lun_se_dev) {
708		target_detach_tg_pt_gp(lun);
709
710		spin_lock(&dev->se_port_lock);
711		list_del(&lun->lun_dev_link);
712		dev->export_count--;
713		rcu_assign_pointer(lun->lun_se_dev, NULL);
714		spin_unlock(&dev->se_port_lock);
715	}
716	if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
717		hlist_del_rcu(&lun->link);
718	mutex_unlock(&tpg->tpg_lun_mutex);
719
720	percpu_ref_exit(&lun->lun_ref);
721}
722