drivers/target/target_core_tpg.c

   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 static DEFINE_XARRAY_ALLOC(tpg_xa);
  35
  36 /*      __core_tpg_get_initiator_node_acl():
  37  *
  38  *      mutex_lock(&tpg->acl_node_mutex); must be held when calling
  39  */
  40 struct se_node_acl *__core_tpg_get_initiator_node_acl(
  41         struct se_portal_group *tpg,
  42         const char *initiatorname)
  43 {
  44         struct se_node_acl *acl;
  45
  46         list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
  47                 if (!strcmp(acl->initiatorname, initiatorname))
  48                         return acl;
  49         }
  50
  51         return NULL;
  52 }
  53
  54 /*      core_tpg_get_initiator_node_acl():
  55  *
  56  *
  57  */
  58 struct se_node_acl *core_tpg_get_initiator_node_acl(
  59         struct se_portal_group *tpg,
  60         unsigned char *initiatorname)
  61 {
  62         struct se_node_acl *acl;
  63         /*
  64          * Obtain se_node_acl->acl_kref using fabric driver provided
  65          * initiatorname[] during node acl endpoint lookup driven by
  66          * new se_session login.
  67          *
  68          * The reference is held until se_session shutdown -> release
  69          * occurs via fabric driver invoked transport_deregister_session()
  70          * or transport_free_session() code.
  71          */
  72         mutex_lock(&tpg->acl_node_mutex);
  73         acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
  74         if (acl) {
  75                 if (!kref_get_unless_zero(&acl->acl_kref))
  76                         acl = NULL;
  77         }
  78         mutex_unlock(&tpg->acl_node_mutex);
  79
  80         return acl;
  81 }
  82 EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);
  83
  84 void core_allocate_nexus_loss_ua(
  85         struct se_node_acl *nacl)
  86 {
  87         struct se_dev_entry *deve;
  88
  89         if (!nacl)
  90                 return;
  91
  92         rcu_read_lock();
  93         hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link)
  94                 core_scsi3_ua_allocate(deve, 0x29,
  95                         ASCQ_29H_NEXUS_LOSS_OCCURRED);
  96         rcu_read_unlock();
  97 }
  98 EXPORT_SYMBOL(core_allocate_nexus_loss_ua);
  99
 100 /*      core_tpg_add_node_to_devs():
 101  *
 102  *
 103  */
 104 void core_tpg_add_node_to_devs(
 105         struct se_node_acl *acl,
 106         struct se_portal_group *tpg,
 107         struct se_lun *lun_orig)
 108 {
 109         bool lun_access_ro = true;
 110         struct se_lun *lun;
 111         struct se_device *dev;
 112
 113         mutex_lock(&tpg->tpg_lun_mutex);
 114         hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link) {
 115                 if (lun_orig && lun != lun_orig)
 116                         continue;
 117
 118                 dev = rcu_dereference_check(lun->lun_se_dev,
 119                                             lockdep_is_held(&tpg->tpg_lun_mutex));
 120                 /*
 121                  * By default in LIO-Target $FABRIC_MOD,
 122                  * demo_mode_write_protect is ON, or READ_ONLY;
 123                  */
 124                 if (!tpg->se_tpg_tfo->tpg_check_demo_mode_write_protect(tpg)) {
 125                         lun_access_ro = false;
 126                 } else {
 127                         /*
 128                          * Allow only optical drives to issue R/W in default RO
 129                          * demo mode.
 130                          */
 131                         if (dev->transport->get_device_type(dev) == TYPE_DISK)
 132                                 lun_access_ro = true;
 133                         else
 134                                 lun_access_ro = false;
 135                 }
 136
 137                 pr_debug("TARGET_CORE[%s]->TPG[%u]_LUN[%llu] - Adding %s"
 138                         " access for LUN in Demo Mode\n",
 139                         tpg->se_tpg_tfo->fabric_name,
 140                         tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
 141                         lun_access_ro ? "READ-ONLY" : "READ-WRITE");
 142
 143                 core_enable_device_list_for_node(lun, NULL, lun->unpacked_lun,
 144                                                  lun_access_ro, acl, tpg);
 145                 /*
 146                  * Check to see if there are any existing persistent reservation
 147                  * APTPL pre-registrations that need to be enabled for this dynamic
 148                  * LUN ACL now..
 149                  */
 150                 core_scsi3_check_aptpl_registration(dev, tpg, lun, acl,
 151                                                     lun->unpacked_lun);
 152         }
 153         mutex_unlock(&tpg->tpg_lun_mutex);
 154 }
 155
 156 static void
 157 target_set_nacl_queue_depth(struct se_portal_group *tpg,
 158                             struct se_node_acl *acl, u32 queue_depth)
 159 {
 160         acl->queue_depth = queue_depth;
 161
 162         if (!acl->queue_depth) {
 163                 pr_warn("Queue depth for %s Initiator Node: %s is 0,"
 164                         "defaulting to 1.\n", tpg->se_tpg_tfo->fabric_name,
 165                         acl->initiatorname);
 166                 acl->queue_depth = 1;
 167         }
 168 }
 169
 170 static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg,
 171                 const unsigned char *initiatorname)
 172 {
 173         struct se_node_acl *acl;
 174         u32 queue_depth;
 175
 176         acl = kzalloc(max(sizeof(*acl), tpg->se_tpg_tfo->node_acl_size),
 177                         GFP_KERNEL);
 178         if (!acl)
 179                 return NULL;
 180
 181         INIT_LIST_HEAD(&acl->acl_list);
 182         INIT_LIST_HEAD(&acl->acl_sess_list);
 183         INIT_HLIST_HEAD(&acl->lun_entry_hlist);
 184         kref_init(&acl->acl_kref);
 185         init_completion(&acl->acl_free_comp);
 186         spin_lock_init(&acl->nacl_sess_lock);
 187         mutex_init(&acl->lun_entry_mutex);
 188         atomic_set(&acl->acl_pr_ref_count, 0);
 189
 190         if (tpg->se_tpg_tfo->tpg_get_default_depth)
 191                 queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
 192         else
 193                 queue_depth = 1;
 194         target_set_nacl_queue_depth(tpg, acl, queue_depth);
 195
 196         snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
 197         acl->se_tpg = tpg;
 198         acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
 199
 200         tpg->se_tpg_tfo->set_default_node_attributes(acl);
 201
 202         return acl;
 203 }
 204
 205 static void target_add_node_acl(struct se_node_acl *acl)
 206 {
 207         struct se_portal_group *tpg = acl->se_tpg;
 208
 209         mutex_lock(&tpg->acl_node_mutex);
 210         list_add_tail(&acl->acl_list, &tpg->acl_node_list);
 211         mutex_unlock(&tpg->acl_node_mutex);
 212
 213         pr_debug("%s_TPG[%hu] - Added %s ACL with TCQ Depth: %d for %s"
 214                 " Initiator Node: %s\n",
 215                 tpg->se_tpg_tfo->fabric_name,
 216                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
 217                 acl->dynamic_node_acl ? "DYNAMIC" : "",
 218                 acl->queue_depth,
 219                 tpg->se_tpg_tfo->fabric_name,
 220                 acl->initiatorname);
 221 }
 222
 223 bool target_tpg_has_node_acl(struct se_portal_group *tpg,
 224                              const char *initiatorname)
 225 {
 226         struct se_node_acl *acl;
 227         bool found = false;
 228
 229         mutex_lock(&tpg->acl_node_mutex);
 230         list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
 231                 if (!strcmp(acl->initiatorname, initiatorname)) {
 232                         found = true;
 233                         break;
 234                 }
 235         }
 236         mutex_unlock(&tpg->acl_node_mutex);
 237
 238         return found;
 239 }
 240 EXPORT_SYMBOL(target_tpg_has_node_acl);
 241
 242 struct se_node_acl *core_tpg_check_initiator_node_acl(
 243         struct se_portal_group *tpg,
 244         unsigned char *initiatorname)
 245 {
 246         struct se_node_acl *acl;
 247
 248         acl = core_tpg_get_initiator_node_acl(tpg, initiatorname);
 249         if (acl)
 250                 return acl;
 251
 252         if (!tpg->se_tpg_tfo->tpg_check_demo_mode(tpg))
 253                 return NULL;
 254
 255         acl = target_alloc_node_acl(tpg, initiatorname);
 256         if (!acl)
 257                 return NULL;
 258         /*
 259          * When allocating a dynamically generated node_acl, go ahead
 260          * and take the extra kref now before returning to the fabric
 261          * driver caller.
 262          *
 263          * Note this reference will be released at session shutdown
 264          * time within transport_free_session() code.
 265          */
 266         kref_get(&acl->acl_kref);
 267         acl->dynamic_node_acl = 1;
 268
 269         /*
 270          * Here we only create demo-mode MappedLUNs from the active
 271          * TPG LUNs if the fabric is not explicitly asking for
 272          * tpg_check_demo_mode_login_only() == 1.
 273          */
 274         if ((tpg->se_tpg_tfo->tpg_check_demo_mode_login_only == NULL) ||
 275             (tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg) != 1))
 276                 core_tpg_add_node_to_devs(acl, tpg, NULL);
 277
 278         target_add_node_acl(acl);
 279         return acl;
 280 }
 281 EXPORT_SYMBOL(core_tpg_check_initiator_node_acl);
 282
 283 void core_tpg_wait_for_nacl_pr_ref(struct se_node_acl *nacl)
 284 {
 285         while (atomic_read(&nacl->acl_pr_ref_count) != 0)
 286                 cpu_relax();
 287 }
 288
 289 struct se_node_acl *core_tpg_add_initiator_node_acl(
 290         struct se_portal_group *tpg,
 291         const char *initiatorname)
 292 {
 293         struct se_node_acl *acl;
 294
 295         mutex_lock(&tpg->acl_node_mutex);
 296         acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
 297         if (acl) {
 298                 if (acl->dynamic_node_acl) {
 299                         acl->dynamic_node_acl = 0;
 300                         pr_debug("%s_TPG[%u] - Replacing dynamic ACL"
 301                                 " for %s\n", tpg->se_tpg_tfo->fabric_name,
 302                                 tpg->se_tpg_tfo->tpg_get_tag(tpg), initiatorname);
 303                         mutex_unlock(&tpg->acl_node_mutex);
 304                         return acl;
 305                 }
 306
 307                 pr_err("ACL entry for %s Initiator"
 308                         " Node %s already exists for TPG %u, ignoring"
 309                         " request.\n",  tpg->se_tpg_tfo->fabric_name,
 310                         initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
 311                 mutex_unlock(&tpg->acl_node_mutex);
 312                 return ERR_PTR(-EEXIST);
 313         }
 314         mutex_unlock(&tpg->acl_node_mutex);
 315
 316         acl = target_alloc_node_acl(tpg, initiatorname);
 317         if (!acl)
 318                 return ERR_PTR(-ENOMEM);
 319
 320         target_add_node_acl(acl);
 321         return acl;
 322 }
 323
 324 static void target_shutdown_sessions(struct se_node_acl *acl)
 325 {
 326         struct se_session *sess;
 327         unsigned long flags;
 328
 329 restart:
 330         spin_lock_irqsave(&acl->nacl_sess_lock, flags);
 331         list_for_each_entry(sess, &acl->acl_sess_list, sess_acl_list) {
 332                 if (sess->cmd_cnt && atomic_read(&sess->cmd_cnt->stopped))
 333                         continue;
 334
 335                 list_del_init(&sess->sess_acl_list);
 336                 spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
 337
 338                 if (acl->se_tpg->se_tpg_tfo->close_session)
 339                         acl->se_tpg->se_tpg_tfo->close_session(sess);
 340                 goto restart;
 341         }
 342         spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
 343 }
 344
 345 void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
 346 {
 347         struct se_portal_group *tpg = acl->se_tpg;
 348
 349         mutex_lock(&tpg->acl_node_mutex);
 350         if (acl->dynamic_node_acl)
 351                 acl->dynamic_node_acl = 0;
 352         list_del_init(&acl->acl_list);
 353         mutex_unlock(&tpg->acl_node_mutex);
 354
 355         target_shutdown_sessions(acl);
 356
 357         target_put_nacl(acl);
 358         /*
 359          * Wait for last target_put_nacl() to complete in target_complete_nacl()
 360          * for active fabric session transport_deregister_session() callbacks.
 361          */
 362         wait_for_completion(&acl->acl_free_comp);
 363
 364         core_tpg_wait_for_nacl_pr_ref(acl);
 365         core_free_device_list_for_node(acl, tpg);
 366
 367         pr_debug("%s_TPG[%hu] - Deleted ACL with TCQ Depth: %d for %s"
 368                 " Initiator Node: %s\n", tpg->se_tpg_tfo->fabric_name,
 369                 tpg->se_tpg_tfo->tpg_get_tag(tpg), acl->queue_depth,
 370                 tpg->se_tpg_tfo->fabric_name, acl->initiatorname);
 371
 372         kfree(acl);
 373 }
 374
 375 /*      core_tpg_set_initiator_node_queue_depth():
 376  *
 377  *
 378  */
 379 int core_tpg_set_initiator_node_queue_depth(
 380         struct se_node_acl *acl,
 381         u32 queue_depth)
 382 {
 383         struct se_portal_group *tpg = acl->se_tpg;
 384
 385         /*
 386          * Allow the setting of se_node_acl queue_depth to be idempotent,
 387          * and not force a session shutdown event if the value is not
 388          * changing.
 389          */
 390         if (acl->queue_depth == queue_depth)
 391                 return 0;
 392         /*
 393          * User has requested to change the queue depth for a Initiator Node.
 394          * Change the value in the Node's struct se_node_acl, and call
 395          * target_set_nacl_queue_depth() to set the new queue depth.
 396          */
 397         target_set_nacl_queue_depth(tpg, acl, queue_depth);
 398
 399         /*
 400          * Shutdown all pending sessions to force session reinstatement.
 401          */
 402         target_shutdown_sessions(acl);
 403
 404         pr_debug("Successfully changed queue depth to: %d for Initiator"
 405                 " Node: %s on %s Target Portal Group: %u\n", acl->queue_depth,
 406                 acl->initiatorname, tpg->se_tpg_tfo->fabric_name,
 407                 tpg->se_tpg_tfo->tpg_get_tag(tpg));
 408
 409         return 0;
 410 }
 411 EXPORT_SYMBOL(core_tpg_set_initiator_node_queue_depth);
 412
 413 /*      core_tpg_set_initiator_node_tag():
 414  *
 415  *      Initiator nodeacl tags are not used internally, but may be used by
 416  *      userspace to emulate aliases or groups.
 417  *      Returns length of newly-set tag or -EINVAL.
 418  */
 419 int core_tpg_set_initiator_node_tag(
 420         struct se_portal_group *tpg,
 421         struct se_node_acl *acl,
 422         const char *new_tag)
 423 {
 424         if (strlen(new_tag) >= MAX_ACL_TAG_SIZE)
 425                 return -EINVAL;
 426
 427         if (!strncmp("NULL", new_tag, 4)) {
 428                 acl->acl_tag[0] = '\0';
 429                 return 0;
 430         }
 431
 432         return snprintf(acl->acl_tag, MAX_ACL_TAG_SIZE, "%s", new_tag);
 433 }
 434 EXPORT_SYMBOL(core_tpg_set_initiator_node_tag);
 435
 436 static void core_tpg_lun_ref_release(struct percpu_ref *ref)
 437 {
 438         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
 439
 440         complete(&lun->lun_shutdown_comp);
 441 }
 442
 443 static int target_tpg_register_rtpi(struct se_portal_group *se_tpg)
 444 {
 445         u32 val;
 446         int ret;
 447
 448         if (se_tpg->rtpi_manual) {
 449                 ret = xa_insert(&tpg_xa, se_tpg->tpg_rtpi, se_tpg, GFP_KERNEL);
 450                 if (ret) {
 451                         pr_info("%s_TPG[%hu] - Can not set RTPI %#x, it is already busy",
 452                                 se_tpg->se_tpg_tfo->fabric_name,
 453                                 se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg),
 454                                 se_tpg->tpg_rtpi);
 455                         return -EINVAL;
 456                 }
 457         } else {
 458                 ret = xa_alloc(&tpg_xa, &val, se_tpg,
 459                                XA_LIMIT(1, USHRT_MAX), GFP_KERNEL);
 460                 if (!ret)
 461                         se_tpg->tpg_rtpi = val;
 462         }
 463
 464         return ret;
 465 }
 466
 467 static void target_tpg_deregister_rtpi(struct se_portal_group *se_tpg)
 468 {
 469         if (se_tpg->tpg_rtpi && se_tpg->enabled)
 470                 xa_erase(&tpg_xa, se_tpg->tpg_rtpi);
 471 }
 472
 473 int target_tpg_enable(struct se_portal_group *se_tpg)
 474 {
 475         int ret;
 476
 477         ret = target_tpg_register_rtpi(se_tpg);
 478         if (ret)
 479                 return ret;
 480
 481         ret = se_tpg->se_tpg_tfo->fabric_enable_tpg(se_tpg, true);
 482         if (ret) {
 483                 target_tpg_deregister_rtpi(se_tpg);
 484                 return ret;
 485         }
 486
 487         se_tpg->enabled = true;
 488
 489         return 0;
 490 }
 491
 492 int target_tpg_disable(struct se_portal_group *se_tpg)
 493 {
 494         int ret;
 495
 496         target_tpg_deregister_rtpi(se_tpg);
 497
 498         ret = se_tpg->se_tpg_tfo->fabric_enable_tpg(se_tpg, false);
 499         if (!ret)
 500                 se_tpg->enabled = false;
 501
 502         return ret;
 503 }
 504
 505 /* Does not change se_wwn->priv. */
 506 int core_tpg_register(
 507         struct se_wwn *se_wwn,
 508         struct se_portal_group *se_tpg,
 509         int proto_id)
 510 {
 511         int ret;
 512
 513         if (!se_tpg)
 514                 return -EINVAL;
 515         /*
 516          * For the typical case where core_tpg_register() is called by a
 517          * fabric driver from target_core_fabric_ops->fabric_make_tpg()
 518          * configfs context, use the original tf_ops pointer already saved
 519          * by target-core in target_fabric_make_wwn().
 520          *
 521          * Otherwise, for special cases like iscsi-target discovery TPGs
 522          * the caller is responsible for setting ->se_tpg_tfo ahead of
 523          * calling core_tpg_register().
 524          */
 525         if (se_wwn)
 526                 se_tpg->se_tpg_tfo = se_wwn->wwn_tf->tf_ops;
 527
 528         if (!se_tpg->se_tpg_tfo) {
 529                 pr_err("Unable to locate se_tpg->se_tpg_tfo pointer\n");
 530                 return -EINVAL;
 531         }
 532
 533         INIT_HLIST_HEAD(&se_tpg->tpg_lun_hlist);
 534         se_tpg->proto_id = proto_id;
 535         se_tpg->se_tpg_wwn = se_wwn;
 536         atomic_set(&se_tpg->tpg_pr_ref_count, 0);
 537         INIT_LIST_HEAD(&se_tpg->acl_node_list);
 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                                 true, g_lun0_dev);
 550                 if (ret < 0) {
 551                         kfree(se_tpg->tpg_virt_lun0);
 552                         return ret;
 553                 }
 554         }
 555
 556         pr_debug("TARGET_CORE[%s]: Allocated portal_group for endpoint: %s, "
 557                  "Proto: %d, Portal Tag: %u\n", se_tpg->se_tpg_tfo->fabric_name,
 558                 se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) ?
 559                 se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) : NULL,
 560                 se_tpg->proto_id, se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
 561
 562         return 0;
 563 }
 564 EXPORT_SYMBOL(core_tpg_register);
 565
 566 int core_tpg_deregister(struct se_portal_group *se_tpg)
 567 {
 568         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 569         struct se_node_acl *nacl, *nacl_tmp;
 570         LIST_HEAD(node_list);
 571
 572         pr_debug("TARGET_CORE[%s]: Deallocating portal_group for endpoint: %s, "
 573                  "Proto: %d, Portal Tag: %u\n", tfo->fabric_name,
 574                 tfo->tpg_get_wwn(se_tpg) ? tfo->tpg_get_wwn(se_tpg) : NULL,
 575                 se_tpg->proto_id, tfo->tpg_get_tag(se_tpg));
 576
 577         while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
 578                 cpu_relax();
 579
 580         mutex_lock(&se_tpg->acl_node_mutex);
 581         list_splice_init(&se_tpg->acl_node_list, &node_list);
 582         mutex_unlock(&se_tpg->acl_node_mutex);
 583         /*
 584          * Release any remaining demo-mode generated se_node_acl that have
 585          * not been released because of TFO->tpg_check_demo_mode_cache() == 1
 586          * in transport_deregister_session().
 587          */
 588         list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) {
 589                 list_del_init(&nacl->acl_list);
 590
 591                 core_tpg_wait_for_nacl_pr_ref(nacl);
 592                 core_free_device_list_for_node(nacl, se_tpg);
 593                 kfree(nacl);
 594         }
 595
 596         if (se_tpg->proto_id >= 0) {
 597                 core_tpg_remove_lun(se_tpg, se_tpg->tpg_virt_lun0);
 598                 kfree_rcu(se_tpg->tpg_virt_lun0, rcu_head);
 599         }
 600
 601         target_tpg_deregister_rtpi(se_tpg);
 602
 603         return 0;
 604 }
 605 EXPORT_SYMBOL(core_tpg_deregister);
 606
 607 struct se_lun *core_tpg_alloc_lun(
 608         struct se_portal_group *tpg,
 609         u64 unpacked_lun)
 610 {
 611         struct se_lun *lun;
 612
 613         lun = kzalloc(sizeof(*lun), GFP_KERNEL);
 614         if (!lun) {
 615                 pr_err("Unable to allocate se_lun memory\n");
 616                 return ERR_PTR(-ENOMEM);
 617         }
 618         lun->unpacked_lun = unpacked_lun;
 619         atomic_set(&lun->lun_acl_count, 0);
 620         init_completion(&lun->lun_shutdown_comp);
 621         INIT_LIST_HEAD(&lun->lun_deve_list);
 622         INIT_LIST_HEAD(&lun->lun_dev_link);
 623         atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
 624         spin_lock_init(&lun->lun_deve_lock);
 625         mutex_init(&lun->lun_tg_pt_md_mutex);
 626         INIT_LIST_HEAD(&lun->lun_tg_pt_gp_link);
 627         spin_lock_init(&lun->lun_tg_pt_gp_lock);
 628         lun->lun_tpg = tpg;
 629
 630         return lun;
 631 }
 632
 633 int core_tpg_add_lun(
 634         struct se_portal_group *tpg,
 635         struct se_lun *lun,
 636         bool lun_access_ro,
 637         struct se_device *dev)
 638 {
 639         int ret;
 640
 641         ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release, 0,
 642                               GFP_KERNEL);
 643         if (ret < 0)
 644                 goto out;
 645
 646         if (!(dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
 647             !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 648                 target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);
 649
 650         mutex_lock(&tpg->tpg_lun_mutex);
 651
 652         spin_lock(&dev->se_port_lock);
 653         lun->lun_index = dev->dev_index;
 654         rcu_assign_pointer(lun->lun_se_dev, dev);
 655         dev->export_count++;
 656         list_add_tail(&lun->lun_dev_link, &dev->dev_sep_list);
 657         spin_unlock(&dev->se_port_lock);
 658
 659         if (dev->dev_flags & DF_READ_ONLY)
 660                 lun->lun_access_ro = true;
 661         else
 662                 lun->lun_access_ro = lun_access_ro;
 663         if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 664                 hlist_add_head_rcu(&lun->link, &tpg->tpg_lun_hlist);
 665         mutex_unlock(&tpg->tpg_lun_mutex);
 666
 667         return 0;
 668
 669 out:
 670         return ret;
 671 }
 672
 673 void core_tpg_remove_lun(
 674         struct se_portal_group *tpg,
 675         struct se_lun *lun)
 676 {
 677         /*
 678          * rcu_dereference_raw protected by se_lun->lun_group symlink
 679          * reference to se_device->dev_group.
 680          */
 681         struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
 682
 683         lun->lun_shutdown = true;
 684
 685         core_clear_lun_from_tpg(lun, tpg);
 686         /*
 687          * Wait for any active I/O references to percpu se_lun->lun_ref to
 688          * be released.  Also, se_lun->lun_ref is now used by PR and ALUA
 689          * logic when referencing a remote target port during ALL_TGT_PT=1
 690          * and generating UNIT_ATTENTIONs for ALUA access state transition.
 691          */
 692         transport_clear_lun_ref(lun);
 693
 694         mutex_lock(&tpg->tpg_lun_mutex);
 695         if (lun->lun_se_dev) {
 696                 target_detach_tg_pt_gp(lun);
 697
 698                 spin_lock(&dev->se_port_lock);
 699                 list_del(&lun->lun_dev_link);
 700                 dev->export_count--;
 701                 rcu_assign_pointer(lun->lun_se_dev, NULL);
 702                 spin_unlock(&dev->se_port_lock);
 703         }
 704         if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 705                 hlist_del_rcu(&lun->link);
 706
 707         lun->lun_shutdown = false;
 708         mutex_unlock(&tpg->tpg_lun_mutex);
 709
 710         percpu_ref_exit(&lun->lun_ref);
 711 }