source: src/linux/universal/linux-4.9/drivers/target/target_core_tpg.c @ 31885

Last change on this file since 31885 was 31885, checked in by brainslayer, 5 weeks ago

update

File size: 17.9 KB
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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         * 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}
97EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);
98
99void 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}
113EXPORT_SYMBOL(core_allocate_nexus_loss_ua);
114
115/*      core_tpg_add_node_to_devs():
116 *
117 *
118 */
119void 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
171static void
172target_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
185static 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
220static 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
238bool 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}
255EXPORT_SYMBOL(target_tpg_has_node_acl);
256
257struct 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}
296EXPORT_SYMBOL(core_tpg_check_initiator_node_acl);
297
298void 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
304struct 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
339static void target_shutdown_sessions(struct se_node_acl *acl)
340{
341        struct se_session *sess;
342        unsigned long flags;
343
344restart:
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
360void 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 */
394int 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}
419EXPORT_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 */
427int 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}
442EXPORT_SYMBOL(core_tpg_set_initiator_node_tag);
443
444static 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_shutdown_comp);
449}
450
451int 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}
514EXPORT_SYMBOL(core_tpg_register);
515
516int 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}
557EXPORT_SYMBOL(core_tpg_deregister);
558
559struct 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_completion(&lun->lun_shutdown_comp);
575        INIT_LIST_HEAD(&lun->lun_deve_list);
576        INIT_LIST_HEAD(&lun->lun_dev_link);
577        atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
578        spin_lock_init(&lun->lun_deve_lock);
579        mutex_init(&lun->lun_tg_pt_md_mutex);
580        INIT_LIST_HEAD(&lun->lun_tg_pt_gp_link);
581        spin_lock_init(&lun->lun_tg_pt_gp_lock);
582        lun->lun_tpg = tpg;
583
584        return lun;
585}
586
587int core_tpg_add_lun(
588        struct se_portal_group *tpg,
589        struct se_lun *lun,
590        bool lun_access_ro,
591        struct se_device *dev)
592{
593        int ret;
594
595        ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release, 0,
596                              GFP_KERNEL);
597        if (ret < 0)
598                goto out;
599
600        ret = core_alloc_rtpi(lun, dev);
601        if (ret)
602                goto out_kill_ref;
603
604        if (!(dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH) &&
605            !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
606                target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);
607
608        mutex_lock(&tpg->tpg_lun_mutex);
609
610        spin_lock(&dev->se_port_lock);
611        lun->lun_index = dev->dev_index;
612        rcu_assign_pointer(lun->lun_se_dev, dev);
613        dev->export_count++;
614        list_add_tail(&lun->lun_dev_link, &dev->dev_sep_list);
615        spin_unlock(&dev->se_port_lock);
616
617        if (dev->dev_flags & DF_READ_ONLY)
618                lun->lun_access_ro = true;
619        else
620                lun->lun_access_ro = lun_access_ro;
621        if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
622                hlist_add_head_rcu(&lun->link, &tpg->tpg_lun_hlist);
623        mutex_unlock(&tpg->tpg_lun_mutex);
624
625        return 0;
626
627out_kill_ref:
628        percpu_ref_exit(&lun->lun_ref);
629out:
630        return ret;
631}
632
633void core_tpg_remove_lun(
634        struct se_portal_group *tpg,
635        struct se_lun *lun)
636{
637        /*
638         * rcu_dereference_raw protected by se_lun->lun_group symlink
639         * reference to se_device->dev_group.
640         */
641        struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
642
643        lun->lun_shutdown = true;
644
645        core_clear_lun_from_tpg(lun, tpg);
646        /*
647         * Wait for any active I/O references to percpu se_lun->lun_ref to
648         * be released.  Also, se_lun->lun_ref is now used by PR and ALUA
649         * logic when referencing a remote target port during ALL_TGT_PT=1
650         * and generating UNIT_ATTENTIONs for ALUA access state transition.
651         */
652        transport_clear_lun_ref(lun);
653
654        mutex_lock(&tpg->tpg_lun_mutex);
655        if (lun->lun_se_dev) {
656                target_detach_tg_pt_gp(lun);
657
658                spin_lock(&dev->se_port_lock);
659                list_del(&lun->lun_dev_link);
660                dev->export_count--;
661                rcu_assign_pointer(lun->lun_se_dev, NULL);
662                spin_unlock(&dev->se_port_lock);
663        }
664        if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
665                hlist_del_rcu(&lun->link);
666
667        lun->lun_shutdown = false;
668        mutex_unlock(&tpg->tpg_lun_mutex);
669
670        percpu_ref_exit(&lun->lun_ref);
671}
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