root/drivers/target/target_core_tpg.c

DEFINITIONS

1. __core_tpg_get_initiator_node_acl
2. core_tpg_get_initiator_node_acl
3. core_allocate_nexus_loss_ua
4. core_tpg_add_node_to_devs
5. target_set_nacl_queue_depth
6. target_alloc_node_acl
7. target_add_node_acl
8. target_tpg_has_node_acl
9. core_tpg_check_initiator_node_acl
10. core_tpg_wait_for_nacl_pr_ref
11. core_tpg_add_initiator_node_acl
12. target_shutdown_sessions
13. core_tpg_del_initiator_node_acl
14. core_tpg_set_initiator_node_queue_depth
15. core_tpg_set_initiator_node_tag
16. core_tpg_lun_ref_release
17. core_tpg_register
18. core_tpg_deregister
19. core_tpg_alloc_lun
20. core_tpg_add_lun
21. core_tpg_remove_lun

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * Filename:  target_core_tpg.c
   4  *
   5  * This file contains generic Target Portal Group related functions.
   6  *
   7  * (c) Copyright 2002-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  ******************************************************************************/
  12 
  13 #include <linux/net.h>
  14 #include <linux/string.h>
  15 #include <linux/timer.h>
  16 #include <linux/slab.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/in.h>
  19 #include <linux/export.h>
  20 #include <net/sock.h>
  21 #include <net/tcp.h>
  22 #include <scsi/scsi_proto.h>
  23 
  24 #include <target/target_core_base.h>
  25 #include <target/target_core_backend.h>
  26 #include <target/target_core_fabric.h>
  27 
  28 #include "target_core_internal.h"
  29 #include "target_core_alua.h"
  30 #include "target_core_pr.h"
  31 #include "target_core_ua.h"
  32 
  33 extern struct se_device *g_lun0_dev;
  34 
  35 static DEFINE_SPINLOCK(tpg_lock);
  36 static LIST_HEAD(tpg_list);
  37 
  38 /*      __core_tpg_get_initiator_node_acl():
  39  *
  40  *      mutex_lock(&tpg->acl_node_mutex); must be held when calling
  41  */
  42 struct se_node_acl *__core_tpg_get_initiator_node_acl(
  43         struct se_portal_group *tpg,
  44         const char *initiatorname)
  45 {
  46         struct se_node_acl *acl;
  47 
  48         list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
  49                 if (!strcmp(acl->initiatorname, initiatorname))
  50                         return acl;
  51         }
  52 
  53         return NULL;
  54 }
  55 
  56 /*      core_tpg_get_initiator_node_acl():
  57  *
  58  *
  59  */
  60 struct se_node_acl *core_tpg_get_initiator_node_acl(
  61         struct se_portal_group *tpg,
  62         unsigned char *initiatorname)
  63 {
  64         struct se_node_acl *acl;
  65         /*
  66          * Obtain se_node_acl->acl_kref using fabric driver provided
  67          * initiatorname[] during node acl endpoint lookup driven by
  68          * new se_session login.
  69          *
  70          * The reference is held until se_session shutdown -> release
  71          * occurs via fabric driver invoked transport_deregister_session()
  72          * or transport_free_session() code.
  73          */
  74         mutex_lock(&tpg->acl_node_mutex);
  75         acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
  76         if (acl) {
  77                 if (!kref_get_unless_zero(&acl->acl_kref))
  78                         acl = NULL;
  79         }
  80         mutex_unlock(&tpg->acl_node_mutex);
  81 
  82         return acl;
  83 }
  84 EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);
  85 
  86 void core_allocate_nexus_loss_ua(
  87         struct se_node_acl *nacl)
  88 {
  89         struct se_dev_entry *deve;
  90 
  91         if (!nacl)
  92                 return;
  93 
  94         rcu_read_lock();
  95         hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link)
  96                 core_scsi3_ua_allocate(deve, 0x29,
  97                         ASCQ_29H_NEXUS_LOSS_OCCURRED);
  98         rcu_read_unlock();
  99 }
 100 EXPORT_SYMBOL(core_allocate_nexus_loss_ua);
 101 
 102 /*      core_tpg_add_node_to_devs():
 103  *
 104  *
 105  */
 106 void core_tpg_add_node_to_devs(
 107         struct se_node_acl *acl,
 108         struct se_portal_group *tpg,
 109         struct se_lun *lun_orig)
 110 {
 111         bool lun_access_ro = true;
 112         struct se_lun *lun;
 113         struct se_device *dev;
 114 
 115         mutex_lock(&tpg->tpg_lun_mutex);
 116         hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link) {
 117                 if (lun_orig && lun != lun_orig)
 118                         continue;
 119 
 120                 dev = rcu_dereference_check(lun->lun_se_dev,
 121                                             lockdep_is_held(&tpg->tpg_lun_mutex));
 122                 /*
 123                  * By default in LIO-Target $FABRIC_MOD,
 124                  * demo_mode_write_protect is ON, or READ_ONLY;
 125                  */
 126                 if (!tpg->se_tpg_tfo->tpg_check_demo_mode_write_protect(tpg)) {
 127                         lun_access_ro = false;
 128                 } else {
 129                         /*
 130                          * Allow only optical drives to issue R/W in default RO
 131                          * demo mode.
 132                          */
 133                         if (dev->transport->get_device_type(dev) == TYPE_DISK)
 134                                 lun_access_ro = true;
 135                         else
 136                                 lun_access_ro = false;
 137                 }
 138 
 139                 pr_debug("TARGET_CORE[%s]->TPG[%u]_LUN[%llu] - Adding %s"
 140                         " access for LUN in Demo Mode\n",
 141                         tpg->se_tpg_tfo->fabric_name,
 142                         tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
 143                         lun_access_ro ? "READ-ONLY" : "READ-WRITE");
 144 
 145                 core_enable_device_list_for_node(lun, NULL, lun->unpacked_lun,
 146                                                  lun_access_ro, acl, tpg);
 147                 /*
 148                  * Check to see if there are any existing persistent reservation
 149                  * APTPL pre-registrations that need to be enabled for this dynamic
 150                  * LUN ACL now..
 151                  */
 152                 core_scsi3_check_aptpl_registration(dev, tpg, lun, acl,
 153                                                     lun->unpacked_lun);
 154         }
 155         mutex_unlock(&tpg->tpg_lun_mutex);
 156 }
 157 
 158 static void
 159 target_set_nacl_queue_depth(struct se_portal_group *tpg,
 160                             struct se_node_acl *acl, u32 queue_depth)
 161 {
 162         acl->queue_depth = queue_depth;
 163 
 164         if (!acl->queue_depth) {
 165                 pr_warn("Queue depth for %s Initiator Node: %s is 0,"
 166                         "defaulting to 1.\n", tpg->se_tpg_tfo->fabric_name,
 167                         acl->initiatorname);
 168                 acl->queue_depth = 1;
 169         }
 170 }
 171 
 172 static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg,
 173                 const unsigned char *initiatorname)
 174 {
 175         struct se_node_acl *acl;
 176         u32 queue_depth;
 177 
 178         acl = kzalloc(max(sizeof(*acl), tpg->se_tpg_tfo->node_acl_size),
 179                         GFP_KERNEL);
 180         if (!acl)
 181                 return NULL;
 182 
 183         INIT_LIST_HEAD(&acl->acl_list);
 184         INIT_LIST_HEAD(&acl->acl_sess_list);
 185         INIT_HLIST_HEAD(&acl->lun_entry_hlist);
 186         kref_init(&acl->acl_kref);
 187         init_completion(&acl->acl_free_comp);
 188         spin_lock_init(&acl->nacl_sess_lock);
 189         mutex_init(&acl->lun_entry_mutex);
 190         atomic_set(&acl->acl_pr_ref_count, 0);
 191 
 192         if (tpg->se_tpg_tfo->tpg_get_default_depth)
 193                 queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
 194         else
 195                 queue_depth = 1;
 196         target_set_nacl_queue_depth(tpg, acl, queue_depth);
 197 
 198         snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
 199         acl->se_tpg = tpg;
 200         acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
 201 
 202         tpg->se_tpg_tfo->set_default_node_attributes(acl);
 203 
 204         return acl;
 205 }
 206 
 207 static void target_add_node_acl(struct se_node_acl *acl)
 208 {
 209         struct se_portal_group *tpg = acl->se_tpg;
 210 
 211         mutex_lock(&tpg->acl_node_mutex);
 212         list_add_tail(&acl->acl_list, &tpg->acl_node_list);
 213         mutex_unlock(&tpg->acl_node_mutex);
 214 
 215         pr_debug("%s_TPG[%hu] - Added %s ACL with TCQ Depth: %d for %s"
 216                 " Initiator Node: %s\n",
 217                 tpg->se_tpg_tfo->fabric_name,
 218                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
 219                 acl->dynamic_node_acl ? "DYNAMIC" : "",
 220                 acl->queue_depth,
 221                 tpg->se_tpg_tfo->fabric_name,
 222                 acl->initiatorname);
 223 }
 224 
 225 bool target_tpg_has_node_acl(struct se_portal_group *tpg,
 226                              const char *initiatorname)
 227 {
 228         struct se_node_acl *acl;
 229         bool found = false;
 230 
 231         mutex_lock(&tpg->acl_node_mutex);
 232         list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
 233                 if (!strcmp(acl->initiatorname, initiatorname)) {
 234                         found = true;
 235                         break;
 236                 }
 237         }
 238         mutex_unlock(&tpg->acl_node_mutex);
 239 
 240         return found;
 241 }
 242 EXPORT_SYMBOL(target_tpg_has_node_acl);
 243 
 244 struct se_node_acl *core_tpg_check_initiator_node_acl(
 245         struct se_portal_group *tpg,
 246         unsigned char *initiatorname)
 247 {
 248         struct se_node_acl *acl;
 249 
 250         acl = core_tpg_get_initiator_node_acl(tpg, initiatorname);
 251         if (acl)
 252                 return acl;
 253 
 254         if (!tpg->se_tpg_tfo->tpg_check_demo_mode(tpg))
 255                 return NULL;
 256 
 257         acl = target_alloc_node_acl(tpg, initiatorname);
 258         if (!acl)
 259                 return NULL;
 260         /*
 261          * When allocating a dynamically generated node_acl, go ahead
 262          * and take the extra kref now before returning to the fabric
 263          * driver caller.
 264          *
 265          * Note this reference will be released at session shutdown
 266          * time within transport_free_session() code.
 267          */
 268         kref_get(&acl->acl_kref);
 269         acl->dynamic_node_acl = 1;
 270 
 271         /*
 272          * Here we only create demo-mode MappedLUNs from the active
 273          * TPG LUNs if the fabric is not explicitly asking for
 274          * tpg_check_demo_mode_login_only() == 1.
 275          */
 276         if ((tpg->se_tpg_tfo->tpg_check_demo_mode_login_only == NULL) ||
 277             (tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg) != 1))
 278                 core_tpg_add_node_to_devs(acl, tpg, NULL);
 279 
 280         target_add_node_acl(acl);
 281         return acl;
 282 }
 283 EXPORT_SYMBOL(core_tpg_check_initiator_node_acl);
 284 
 285 void core_tpg_wait_for_nacl_pr_ref(struct se_node_acl *nacl)
 286 {
 287         while (atomic_read(&nacl->acl_pr_ref_count) != 0)
 288                 cpu_relax();
 289 }
 290 
 291 struct se_node_acl *core_tpg_add_initiator_node_acl(
 292         struct se_portal_group *tpg,
 293         const char *initiatorname)
 294 {
 295         struct se_node_acl *acl;
 296 
 297         mutex_lock(&tpg->acl_node_mutex);
 298         acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
 299         if (acl) {
 300                 if (acl->dynamic_node_acl) {
 301                         acl->dynamic_node_acl = 0;
 302                         pr_debug("%s_TPG[%u] - Replacing dynamic ACL"
 303                                 " for %s\n", tpg->se_tpg_tfo->fabric_name,
 304                                 tpg->se_tpg_tfo->tpg_get_tag(tpg), initiatorname);
 305                         mutex_unlock(&tpg->acl_node_mutex);
 306                         return acl;
 307                 }
 308 
 309                 pr_err("ACL entry for %s Initiator"
 310                         " Node %s already exists for TPG %u, ignoring"
 311                         " request.\n",  tpg->se_tpg_tfo->fabric_name,
 312                         initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
 313                 mutex_unlock(&tpg->acl_node_mutex);
 314                 return ERR_PTR(-EEXIST);
 315         }
 316         mutex_unlock(&tpg->acl_node_mutex);
 317 
 318         acl = target_alloc_node_acl(tpg, initiatorname);
 319         if (!acl)
 320                 return ERR_PTR(-ENOMEM);
 321 
 322         target_add_node_acl(acl);
 323         return acl;
 324 }
 325 
 326 static void target_shutdown_sessions(struct se_node_acl *acl)
 327 {
 328         struct se_session *sess;
 329         unsigned long flags;
 330 
 331 restart:
 332         spin_lock_irqsave(&acl->nacl_sess_lock, flags);
 333         list_for_each_entry(sess, &acl->acl_sess_list, sess_acl_list) {
 334                 if (sess->sess_tearing_down)
 335                         continue;
 336 
 337                 list_del_init(&sess->sess_acl_list);
 338                 spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
 339 
 340                 if (acl->se_tpg->se_tpg_tfo->close_session)
 341                         acl->se_tpg->se_tpg_tfo->close_session(sess);
 342                 goto restart;
 343         }
 344         spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
 345 }
 346 
 347 void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
 348 {
 349         struct se_portal_group *tpg = acl->se_tpg;
 350 
 351         mutex_lock(&tpg->acl_node_mutex);
 352         if (acl->dynamic_node_acl)
 353                 acl->dynamic_node_acl = 0;
 354         list_del_init(&acl->acl_list);
 355         mutex_unlock(&tpg->acl_node_mutex);
 356 
 357         target_shutdown_sessions(acl);
 358 
 359         target_put_nacl(acl);
 360         /*
 361          * Wait for last target_put_nacl() to complete in target_complete_nacl()
 362          * for active fabric session transport_deregister_session() callbacks.
 363          */
 364         wait_for_completion(&acl->acl_free_comp);
 365 
 366         core_tpg_wait_for_nacl_pr_ref(acl);
 367         core_free_device_list_for_node(acl, tpg);
 368 
 369         pr_debug("%s_TPG[%hu] - Deleted ACL with TCQ Depth: %d for %s"
 370                 " Initiator Node: %s\n", tpg->se_tpg_tfo->fabric_name,
 371                 tpg->se_tpg_tfo->tpg_get_tag(tpg), acl->queue_depth,
 372                 tpg->se_tpg_tfo->fabric_name, acl->initiatorname);
 373 
 374         kfree(acl);
 375 }
 376 
 377 /*      core_tpg_set_initiator_node_queue_depth():
 378  *
 379  *
 380  */
 381 int core_tpg_set_initiator_node_queue_depth(
 382         struct se_node_acl *acl,
 383         u32 queue_depth)
 384 {
 385         struct se_portal_group *tpg = acl->se_tpg;
 386 
 387         /*
 388          * Allow the setting of se_node_acl queue_depth to be idempotent,
 389          * and not force a session shutdown event if the value is not
 390          * changing.
 391          */
 392         if (acl->queue_depth == queue_depth)
 393                 return 0;
 394         /*
 395          * User has requested to change the queue depth for a Initiator Node.
 396          * Change the value in the Node's struct se_node_acl, and call
 397          * target_set_nacl_queue_depth() to set the new queue depth.
 398          */
 399         target_set_nacl_queue_depth(tpg, acl, queue_depth);
 400 
 401         /*
 402          * Shutdown all pending sessions to force session reinstatement.
 403          */
 404         target_shutdown_sessions(acl);
 405 
 406         pr_debug("Successfully changed queue depth to: %d for Initiator"
 407                 " Node: %s on %s Target Portal Group: %u\n", acl->queue_depth,
 408                 acl->initiatorname, tpg->se_tpg_tfo->fabric_name,
 409                 tpg->se_tpg_tfo->tpg_get_tag(tpg));
 410 
 411         return 0;
 412 }
 413 EXPORT_SYMBOL(core_tpg_set_initiator_node_queue_depth);
 414 
 415 /*      core_tpg_set_initiator_node_tag():
 416  *
 417  *      Initiator nodeacl tags are not used internally, but may be used by
 418  *      userspace to emulate aliases or groups.
 419  *      Returns length of newly-set tag or -EINVAL.
 420  */
 421 int core_tpg_set_initiator_node_tag(
 422         struct se_portal_group *tpg,
 423         struct se_node_acl *acl,
 424         const char *new_tag)
 425 {
 426         if (strlen(new_tag) >= MAX_ACL_TAG_SIZE)
 427                 return -EINVAL;
 428 
 429         if (!strncmp("NULL", new_tag, 4)) {
 430                 acl->acl_tag[0] = '\0';
 431                 return 0;
 432         }
 433 
 434         return snprintf(acl->acl_tag, MAX_ACL_TAG_SIZE, "%s", new_tag);
 435 }
 436 EXPORT_SYMBOL(core_tpg_set_initiator_node_tag);
 437 
 438 static void core_tpg_lun_ref_release(struct percpu_ref *ref)
 439 {
 440         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
 441 
 442         complete(&lun->lun_shutdown_comp);
 443 }
 444 
 445 /* Does not change se_wwn->priv. */
 446 int core_tpg_register(
 447         struct se_wwn *se_wwn,
 448         struct se_portal_group *se_tpg,
 449         int proto_id)
 450 {
 451         int ret;
 452 
 453         if (!se_tpg)
 454                 return -EINVAL;
 455         /*
 456          * For the typical case where core_tpg_register() is called by a
 457          * fabric driver from target_core_fabric_ops->fabric_make_tpg()
 458          * configfs context, use the original tf_ops pointer already saved
 459          * by target-core in target_fabric_make_wwn().
 460          *
 461          * Otherwise, for special cases like iscsi-target discovery TPGs
 462          * the caller is responsible for setting ->se_tpg_tfo ahead of
 463          * calling core_tpg_register().
 464          */
 465         if (se_wwn)
 466                 se_tpg->se_tpg_tfo = se_wwn->wwn_tf->tf_ops;
 467 
 468         if (!se_tpg->se_tpg_tfo) {
 469                 pr_err("Unable to locate se_tpg->se_tpg_tfo pointer\n");
 470                 return -EINVAL;
 471         }
 472 
 473         INIT_HLIST_HEAD(&se_tpg->tpg_lun_hlist);
 474         se_tpg->proto_id = proto_id;
 475         se_tpg->se_tpg_wwn = se_wwn;
 476         atomic_set(&se_tpg->tpg_pr_ref_count, 0);
 477         INIT_LIST_HEAD(&se_tpg->acl_node_list);
 478         INIT_LIST_HEAD(&se_tpg->se_tpg_node);
 479         INIT_LIST_HEAD(&se_tpg->tpg_sess_list);
 480         spin_lock_init(&se_tpg->session_lock);
 481         mutex_init(&se_tpg->tpg_lun_mutex);
 482         mutex_init(&se_tpg->acl_node_mutex);
 483 
 484         if (se_tpg->proto_id >= 0) {
 485                 se_tpg->tpg_virt_lun0 = core_tpg_alloc_lun(se_tpg, 0);
 486                 if (IS_ERR(se_tpg->tpg_virt_lun0))
 487                         return PTR_ERR(se_tpg->tpg_virt_lun0);
 488 
 489                 ret = core_tpg_add_lun(se_tpg, se_tpg->tpg_virt_lun0,
 490                                 true, g_lun0_dev);
 491                 if (ret < 0) {
 492                         kfree(se_tpg->tpg_virt_lun0);
 493                         return ret;
 494                 }
 495         }
 496 
 497         spin_lock_bh(&tpg_lock);
 498         list_add_tail(&se_tpg->se_tpg_node, &tpg_list);
 499         spin_unlock_bh(&tpg_lock);
 500 
 501         pr_debug("TARGET_CORE[%s]: Allocated portal_group for endpoint: %s, "
 502                  "Proto: %d, Portal Tag: %u\n", se_tpg->se_tpg_tfo->fabric_name,
 503                 se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) ?
 504                 se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) : NULL,
 505                 se_tpg->proto_id, se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
 506 
 507         return 0;
 508 }
 509 EXPORT_SYMBOL(core_tpg_register);
 510 
 511 int core_tpg_deregister(struct se_portal_group *se_tpg)
 512 {
 513         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 514         struct se_node_acl *nacl, *nacl_tmp;
 515         LIST_HEAD(node_list);
 516 
 517         pr_debug("TARGET_CORE[%s]: Deallocating portal_group for endpoint: %s, "
 518                  "Proto: %d, Portal Tag: %u\n", tfo->fabric_name,
 519                 tfo->tpg_get_wwn(se_tpg) ? tfo->tpg_get_wwn(se_tpg) : NULL,
 520                 se_tpg->proto_id, tfo->tpg_get_tag(se_tpg));
 521 
 522         spin_lock_bh(&tpg_lock);
 523         list_del(&se_tpg->se_tpg_node);
 524         spin_unlock_bh(&tpg_lock);
 525 
 526         while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
 527                 cpu_relax();
 528 
 529         mutex_lock(&se_tpg->acl_node_mutex);
 530         list_splice_init(&se_tpg->acl_node_list, &node_list);
 531         mutex_unlock(&se_tpg->acl_node_mutex);
 532         /*
 533          * Release any remaining demo-mode generated se_node_acl that have
 534          * not been released because of TFO->tpg_check_demo_mode_cache() == 1
 535          * in transport_deregister_session().
 536          */
 537         list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) {
 538                 list_del_init(&nacl->acl_list);
 539 
 540                 core_tpg_wait_for_nacl_pr_ref(nacl);
 541                 core_free_device_list_for_node(nacl, se_tpg);
 542                 kfree(nacl);
 543         }
 544 
 545         if (se_tpg->proto_id >= 0) {
 546                 core_tpg_remove_lun(se_tpg, se_tpg->tpg_virt_lun0);
 547                 kfree_rcu(se_tpg->tpg_virt_lun0, rcu_head);
 548         }
 549 
 550         return 0;
 551 }
 552 EXPORT_SYMBOL(core_tpg_deregister);
 553 
 554 struct se_lun *core_tpg_alloc_lun(
 555         struct se_portal_group *tpg,
 556         u64 unpacked_lun)
 557 {
 558         struct se_lun *lun;
 559 
 560         lun = kzalloc(sizeof(*lun), GFP_KERNEL);
 561         if (!lun) {
 562                 pr_err("Unable to allocate se_lun memory\n");
 563                 return ERR_PTR(-ENOMEM);
 564         }
 565         lun->unpacked_lun = unpacked_lun;
 566         atomic_set(&lun->lun_acl_count, 0);
 567         init_completion(&lun->lun_shutdown_comp);
 568         INIT_LIST_HEAD(&lun->lun_deve_list);
 569         INIT_LIST_HEAD(&lun->lun_dev_link);
 570         atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
 571         spin_lock_init(&lun->lun_deve_lock);
 572         mutex_init(&lun->lun_tg_pt_md_mutex);
 573         INIT_LIST_HEAD(&lun->lun_tg_pt_gp_link);
 574         spin_lock_init(&lun->lun_tg_pt_gp_lock);
 575         lun->lun_tpg = tpg;
 576 
 577         return lun;
 578 }
 579 
 580 int core_tpg_add_lun(
 581         struct se_portal_group *tpg,
 582         struct se_lun *lun,
 583         bool lun_access_ro,
 584         struct se_device *dev)
 585 {
 586         int ret;
 587 
 588         ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release, 0,
 589                               GFP_KERNEL);
 590         if (ret < 0)
 591                 goto out;
 592 
 593         ret = core_alloc_rtpi(lun, dev);
 594         if (ret)
 595                 goto out_kill_ref;
 596 
 597         if (!(dev->transport->transport_flags &
 598              TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
 599             !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 600                 target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);
 601 
 602         mutex_lock(&tpg->tpg_lun_mutex);
 603 
 604         spin_lock(&dev->se_port_lock);
 605         lun->lun_index = dev->dev_index;
 606         rcu_assign_pointer(lun->lun_se_dev, dev);
 607         dev->export_count++;
 608         list_add_tail(&lun->lun_dev_link, &dev->dev_sep_list);
 609         spin_unlock(&dev->se_port_lock);
 610 
 611         if (dev->dev_flags & DF_READ_ONLY)
 612                 lun->lun_access_ro = true;
 613         else
 614                 lun->lun_access_ro = lun_access_ro;
 615         if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 616                 hlist_add_head_rcu(&lun->link, &tpg->tpg_lun_hlist);
 617         mutex_unlock(&tpg->tpg_lun_mutex);
 618 
 619         return 0;
 620 
 621 out_kill_ref:
 622         percpu_ref_exit(&lun->lun_ref);
 623 out:
 624         return ret;
 625 }
 626 
 627 void core_tpg_remove_lun(
 628         struct se_portal_group *tpg,
 629         struct se_lun *lun)
 630 {
 631         /*
 632          * rcu_dereference_raw protected by se_lun->lun_group symlink
 633          * reference to se_device->dev_group.
 634          */
 635         struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
 636 
 637         lun->lun_shutdown = true;
 638 
 639         core_clear_lun_from_tpg(lun, tpg);
 640         /*
 641          * Wait for any active I/O references to percpu se_lun->lun_ref to
 642          * be released.  Also, se_lun->lun_ref is now used by PR and ALUA
 643          * logic when referencing a remote target port during ALL_TGT_PT=1
 644          * and generating UNIT_ATTENTIONs for ALUA access state transition.
 645          */
 646         transport_clear_lun_ref(lun);
 647 
 648         mutex_lock(&tpg->tpg_lun_mutex);
 649         if (lun->lun_se_dev) {
 650                 target_detach_tg_pt_gp(lun);
 651 
 652                 spin_lock(&dev->se_port_lock);
 653                 list_del(&lun->lun_dev_link);
 654                 dev->export_count--;
 655                 rcu_assign_pointer(lun->lun_se_dev, NULL);
 656                 spin_unlock(&dev->se_port_lock);
 657         }
 658         if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 659                 hlist_del_rcu(&lun->link);
 660 
 661         lun->lun_shutdown = false;
 662         mutex_unlock(&tpg->tpg_lun_mutex);
 663 
 664         percpu_ref_exit(&lun->lun_ref);
 665 }