drivers/target/target_core_tpg.c

   1 /*******************************************************************************
   2  * Filename:  target_core_tpg.c
   3  *
   4  * This file contains generic Target Portal Group related functions.
   5  *
   6  * (c) Copyright 2002-2013 Datera, Inc.
   7  *
   8  * Nicholas A. Bellinger <nab@kernel.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  *
  24  ******************************************************************************/
  25
  26 #include <linux/net.h>
  27 #include <linux/string.h>
  28 #include <linux/timer.h>
  29 #include <linux/slab.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/in.h>
  32 #include <linux/export.h>
  33 #include <net/sock.h>
  34 #include <net/tcp.h>
  35 #include <scsi/scsi_proto.h>
  36
  37 #include <target/target_core_base.h>
  38 #include <target/target_core_backend.h>
  39 #include <target/target_core_fabric.h>
  40
  41 #include "target_core_internal.h"
  42 #include "target_core_alua.h"
  43 #include "target_core_pr.h"
  44 #include "target_core_ua.h"
  45
  46 extern struct se_device *g_lun0_dev;
  47
  48 static DEFINE_SPINLOCK(tpg_lock);
  49 static LIST_HEAD(tpg_list);
  50
  51 /*      __core_tpg_get_initiator_node_acl():
  52  *
  53  *      mutex_lock(&tpg->acl_node_mutex); must be held when calling
  54  */
  55 struct se_node_acl *__core_tpg_get_initiator_node_acl(
  56         struct se_portal_group *tpg,
  57         const char *initiatorname)
  58 {
  59         struct se_node_acl *acl;
  60
  61         list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
  62                 if (!strcmp(acl->initiatorname, initiatorname))
  63                         return acl;
  64         }
  65
  66         return NULL;
  67 }
  68
  69 /*      core_tpg_get_initiator_node_acl():
  70  *
  71  *
  72  */
  73 struct se_node_acl *core_tpg_get_initiator_node_acl(
  74         struct se_portal_group *tpg,
  75         unsigned char *initiatorname)
  76 {
  77         struct se_node_acl *acl;
  78
  79         mutex_lock(&tpg->acl_node_mutex);
  80         acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
  81         mutex_unlock(&tpg->acl_node_mutex);
  82
  83         return acl;
  84 }
  85 EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);
  86
  87 void core_allocate_nexus_loss_ua(
  88         struct se_node_acl *nacl)
  89 {
  90         struct se_dev_entry *deve;
  91
  92         if (!nacl)
  93                 return;
  94
  95         rcu_read_lock();
  96         hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link)
  97                 core_scsi3_ua_allocate(deve, 0x29,
  98                         ASCQ_29H_NEXUS_LOSS_OCCURRED);
  99         rcu_read_unlock();
 100 }
 101 EXPORT_SYMBOL(core_allocate_nexus_loss_ua);
 102
 103 /*      core_tpg_add_node_to_devs():
 104  *
 105  *
 106  */
 107 void core_tpg_add_node_to_devs(
 108         struct se_node_acl *acl,
 109         struct se_portal_group *tpg,
 110         struct se_lun *lun_orig)
 111 {
 112         u32 lun_access = 0;
 113         struct se_lun *lun;
 114         struct se_device *dev;
 115
 116         mutex_lock(&tpg->tpg_lun_mutex);
 117         hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link) {
 118                 if (lun_orig && lun != lun_orig)
 119                         continue;
 120
 121                 dev = rcu_dereference_check(lun->lun_se_dev,
 122                                             lockdep_is_held(&tpg->tpg_lun_mutex));
 123                 /*
 124                  * By default in LIO-Target $FABRIC_MOD,
 125                  * demo_mode_write_protect is ON, or READ_ONLY;
 126                  */
 127                 if (!tpg->se_tpg_tfo->tpg_check_demo_mode_write_protect(tpg)) {
 128                         lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;
 129                 } else {
 130                         /*
 131                          * Allow only optical drives to issue R/W in default RO
 132                          * demo mode.
 133                          */
 134                         if (dev->transport->get_device_type(dev) == TYPE_DISK)
 135                                 lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;
 136                         else
 137                                 lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;
 138                 }
 139
 140                 pr_debug("TARGET_CORE[%s]->TPG[%u]_LUN[%llu] - Adding %s"
 141                         " access for LUN in Demo Mode\n",
 142                         tpg->se_tpg_tfo->get_fabric_name(),
 143                         tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
 144                         (lun_access == TRANSPORT_LUNFLAGS_READ_WRITE) ?
 145                         "READ-WRITE" : "READ-ONLY");
 146
 147                 core_enable_device_list_for_node(lun, NULL, lun->unpacked_lun,
 148                                                  lun_access, acl, tpg);
 149                 /*
 150                  * Check to see if there are any existing persistent reservation
 151                  * APTPL pre-registrations that need to be enabled for this dynamic
 152                  * LUN ACL now..
 153                  */
 154                 core_scsi3_check_aptpl_registration(dev, tpg, lun, acl,
 155                                                     lun->unpacked_lun);
 156         }
 157         mutex_unlock(&tpg->tpg_lun_mutex);
 158 }
 159
 160 /*      core_set_queue_depth_for_node():
 161  *
 162  *
 163  */
 164 static int core_set_queue_depth_for_node(
 165         struct se_portal_group *tpg,
 166         struct se_node_acl *acl)
 167 {
 168         if (!acl->queue_depth) {
 169                 pr_err("Queue depth for %s Initiator Node: %s is 0,"
 170                         "defaulting to 1.\n", tpg->se_tpg_tfo->get_fabric_name(),
 171                         acl->initiatorname);
 172                 acl->queue_depth = 1;
 173         }
 174
 175         return 0;
 176 }
 177
 178 static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg,
 179                 const unsigned char *initiatorname)
 180 {
 181         struct se_node_acl *acl;
 182
 183         acl = kzalloc(max(sizeof(*acl), tpg->se_tpg_tfo->node_acl_size),
 184                         GFP_KERNEL);
 185         if (!acl)
 186                 return NULL;
 187
 188         INIT_LIST_HEAD(&acl->acl_list);
 189         INIT_LIST_HEAD(&acl->acl_sess_list);
 190         INIT_HLIST_HEAD(&acl->lun_entry_hlist);
 191         kref_init(&acl->acl_kref);
 192         init_completion(&acl->acl_free_comp);
 193         spin_lock_init(&acl->nacl_sess_lock);
 194         mutex_init(&acl->lun_entry_mutex);
 195         atomic_set(&acl->acl_pr_ref_count, 0);
 196         if (tpg->se_tpg_tfo->tpg_get_default_depth)
 197                 acl->queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
 198         else
 199                 acl->queue_depth = 1;
 200         snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
 201         acl->se_tpg = tpg;
 202         acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
 203
 204         tpg->se_tpg_tfo->set_default_node_attributes(acl);
 205
 206         if (core_set_queue_depth_for_node(tpg, acl) < 0)
 207                 goto out_free_acl;
 208
 209         return acl;
 210
 211 out_free_acl:
 212         kfree(acl);
 213         return NULL;
 214 }
 215
 216 static void target_add_node_acl(struct se_node_acl *acl)
 217 {
 218         struct se_portal_group *tpg = acl->se_tpg;
 219
 220         mutex_lock(&tpg->acl_node_mutex);
 221         list_add_tail(&acl->acl_list, &tpg->acl_node_list);
 222         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
 235 struct 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 }
 265 EXPORT_SYMBOL(core_tpg_check_initiator_node_acl);
 266
 267 void 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
 273 struct 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
 308 void 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  */
 368 int 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 }
 473 EXPORT_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  */
 481 int 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 }
 496 EXPORT_SYMBOL(core_tpg_set_initiator_node_tag);
 497
 498 static 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
 505 int 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 }
 568 EXPORT_SYMBOL(core_tpg_register);
 569
 570 int 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 }
 612 EXPORT_SYMBOL(core_tpg_deregister);
 613
 614 struct 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
 641 int 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
 681 out_kill_ref:
 682         percpu_ref_exit(&lun->lun_ref);
 683 out:
 684         return ret;
 685 }
 686
 687 void 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 }