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          * 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 }
  97 EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);
  98
  99 void 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 }
 113 EXPORT_SYMBOL(core_allocate_nexus_loss_ua);
 114
 115 /*      core_tpg_add_node_to_devs():
 116  *
 117  *
 118  */
 119 void 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         u32 lun_access = 0;
 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 = TRANSPORT_LUNFLAGS_READ_WRITE;
 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 = TRANSPORT_LUNFLAGS_READ_ONLY;
 148                         else
 149                                 lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;
 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 == TRANSPORT_LUNFLAGS_READ_WRITE) ?
 157                         "READ-WRITE" : "READ-ONLY");
 158
 159                 core_enable_device_list_for_node(lun, NULL, lun->unpacked_lun,
 160                                                  lun_access, acl, tpg);
 161                 /*
 162                  * Check to see if there are any existing persistent reservation
 163                  * APTPL pre-registrations that need to be enabled for this dynamic
 164                  * LUN ACL now..
 165                  */
 166                 core_scsi3_check_aptpl_registration(dev, tpg, lun, acl,
 167                                                     lun->unpacked_lun);
 168         }
 169         mutex_unlock(&tpg->tpg_lun_mutex);
 170 }
 171
 172 static void
 173 target_set_nacl_queue_depth(struct se_portal_group *tpg,
 174                             struct se_node_acl *acl, u32 queue_depth)
 175 {
 176         acl->queue_depth = queue_depth;
 177
 178         if (!acl->queue_depth) {
 179                 pr_warn("Queue depth for %s Initiator Node: %s is 0,"
 180                         "defaulting to 1.\n", tpg->se_tpg_tfo->get_fabric_name(),
 181                         acl->initiatorname);
 182                 acl->queue_depth = 1;
 183         }
 184 }
 185
 186 static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg,
 187                 const unsigned char *initiatorname)
 188 {
 189         struct se_node_acl *acl;
 190         u32 queue_depth;
 191
 192         acl = kzalloc(max(sizeof(*acl), tpg->se_tpg_tfo->node_acl_size),
 193                         GFP_KERNEL);
 194         if (!acl)
 195                 return NULL;
 196
 197         INIT_LIST_HEAD(&acl->acl_list);
 198         INIT_LIST_HEAD(&acl->acl_sess_list);
 199         INIT_HLIST_HEAD(&acl->lun_entry_hlist);
 200         kref_init(&acl->acl_kref);
 201         init_completion(&acl->acl_free_comp);
 202         spin_lock_init(&acl->nacl_sess_lock);
 203         mutex_init(&acl->lun_entry_mutex);
 204         atomic_set(&acl->acl_pr_ref_count, 0);
 205
 206         if (tpg->se_tpg_tfo->tpg_get_default_depth)
 207                 queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
 208         else
 209                 queue_depth = 1;
 210         target_set_nacl_queue_depth(tpg, acl, queue_depth);
 211
 212         snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
 213         acl->se_tpg = tpg;
 214         acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
 215
 216         tpg->se_tpg_tfo->set_default_node_attributes(acl);
 217
 218         return acl;
 219 }
 220
 221 static void target_add_node_acl(struct se_node_acl *acl)
 222 {
 223         struct se_portal_group *tpg = acl->se_tpg;
 224
 225         mutex_lock(&tpg->acl_node_mutex);
 226         list_add_tail(&acl->acl_list, &tpg->acl_node_list);
 227         mutex_unlock(&tpg->acl_node_mutex);
 228
 229         pr_debug("%s_TPG[%hu] - Added %s ACL with TCQ Depth: %d for %s"
 230                 " Initiator Node: %s\n",
 231                 tpg->se_tpg_tfo->get_fabric_name(),
 232                 tpg->se_tpg_tfo->tpg_get_tag(tpg),
 233                 acl->dynamic_node_acl ? "DYNAMIC" : "",
 234                 acl->queue_depth,
 235                 tpg->se_tpg_tfo->get_fabric_name(),
 236                 acl->initiatorname);
 237 }
 238
 239 bool target_tpg_has_node_acl(struct se_portal_group *tpg,
 240                              const char *initiatorname)
 241 {
 242         struct se_node_acl *acl;
 243         bool found = false;
 244
 245         mutex_lock(&tpg->acl_node_mutex);
 246         list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
 247                 if (!strcmp(acl->initiatorname, initiatorname)) {
 248                         found = true;
 249                         break;
 250                 }
 251         }
 252         mutex_unlock(&tpg->acl_node_mutex);
 253
 254         return found;
 255 }
 256 EXPORT_SYMBOL(target_tpg_has_node_acl);
 257
 258 struct se_node_acl *core_tpg_check_initiator_node_acl(
 259         struct se_portal_group *tpg,
 260         unsigned char *initiatorname)
 261 {
 262         struct se_node_acl *acl;
 263
 264         acl = core_tpg_get_initiator_node_acl(tpg, initiatorname);
 265         if (acl)
 266                 return acl;
 267
 268         if (!tpg->se_tpg_tfo->tpg_check_demo_mode(tpg))
 269                 return NULL;
 270
 271         acl = target_alloc_node_acl(tpg, initiatorname);
 272         if (!acl)
 273                 return NULL;
 274         /*
 275          * When allocating a dynamically generated node_acl, go ahead
 276          * and take the extra kref now before returning to the fabric
 277          * driver caller.
 278          *
 279          * Note this reference will be released at session shutdown
 280          * time within transport_free_session() code.
 281          */
 282         kref_get(&acl->acl_kref);
 283         acl->dynamic_node_acl = 1;
 284
 285         /*
 286          * Here we only create demo-mode MappedLUNs from the active
 287          * TPG LUNs if the fabric is not explicitly asking for
 288          * tpg_check_demo_mode_login_only() == 1.
 289          */
 290         if ((tpg->se_tpg_tfo->tpg_check_demo_mode_login_only == NULL) ||
 291             (tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg) != 1))
 292                 core_tpg_add_node_to_devs(acl, tpg, NULL);
 293
 294         target_add_node_acl(acl);
 295         return acl;
 296 }
 297 EXPORT_SYMBOL(core_tpg_check_initiator_node_acl);
 298
 299 void core_tpg_wait_for_nacl_pr_ref(struct se_node_acl *nacl)
 300 {
 301         while (atomic_read(&nacl->acl_pr_ref_count) != 0)
 302                 cpu_relax();
 303 }
 304
 305 struct se_node_acl *core_tpg_add_initiator_node_acl(
 306         struct se_portal_group *tpg,
 307         const char *initiatorname)
 308 {
 309         struct se_node_acl *acl;
 310
 311         mutex_lock(&tpg->acl_node_mutex);
 312         acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
 313         if (acl) {
 314                 if (acl->dynamic_node_acl) {
 315                         acl->dynamic_node_acl = 0;
 316                         pr_debug("%s_TPG[%u] - Replacing dynamic ACL"
 317                                 " for %s\n", tpg->se_tpg_tfo->get_fabric_name(),
 318                                 tpg->se_tpg_tfo->tpg_get_tag(tpg), initiatorname);
 319                         mutex_unlock(&tpg->acl_node_mutex);
 320                         return acl;
 321                 }
 322
 323                 pr_err("ACL entry for %s Initiator"
 324                         " Node %s already exists for TPG %u, ignoring"
 325                         " request.\n",  tpg->se_tpg_tfo->get_fabric_name(),
 326                         initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
 327                 mutex_unlock(&tpg->acl_node_mutex);
 328                 return ERR_PTR(-EEXIST);
 329         }
 330         mutex_unlock(&tpg->acl_node_mutex);
 331
 332         acl = target_alloc_node_acl(tpg, initiatorname);
 333         if (!acl)
 334                 return ERR_PTR(-ENOMEM);
 335
 336         target_add_node_acl(acl);
 337         return acl;
 338 }
 339
 340 void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
 341 {
 342         struct se_portal_group *tpg = acl->se_tpg;
 343         LIST_HEAD(sess_list);
 344         struct se_session *sess, *sess_tmp;
 345         unsigned long flags;
 346         int rc;
 347
 348         mutex_lock(&tpg->acl_node_mutex);
 349         if (acl->dynamic_node_acl) {
 350                 acl->dynamic_node_acl = 0;
 351         }
 352         list_del(&acl->acl_list);
 353         mutex_unlock(&tpg->acl_node_mutex);
 354
 355         spin_lock_irqsave(&acl->nacl_sess_lock, flags);
 356         acl->acl_stop = 1;
 357
 358         list_for_each_entry_safe(sess, sess_tmp, &acl->acl_sess_list,
 359                                 sess_acl_list) {
 360                 if (sess->sess_tearing_down != 0)
 361                         continue;
 362
 363                 if (!target_get_session(sess))
 364                         continue;
 365                 list_move(&sess->sess_acl_list, &sess_list);
 366         }
 367         spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
 368
 369         list_for_each_entry_safe(sess, sess_tmp, &sess_list, sess_acl_list) {
 370                 list_del(&sess->sess_acl_list);
 371
 372                 rc = tpg->se_tpg_tfo->shutdown_session(sess);
 373                 target_put_session(sess);
 374                 if (!rc)
 375                         continue;
 376                 target_put_session(sess);
 377         }
 378         target_put_nacl(acl);
 379         /*
 380          * Wait for last target_put_nacl() to complete in target_complete_nacl()
 381          * for active fabric session transport_deregister_session() callbacks.
 382          */
 383         wait_for_completion(&acl->acl_free_comp);
 384
 385         core_tpg_wait_for_nacl_pr_ref(acl);
 386         core_free_device_list_for_node(acl, tpg);
 387
 388         pr_debug("%s_TPG[%hu] - Deleted ACL with TCQ Depth: %d for %s"
 389                 " Initiator Node: %s\n", tpg->se_tpg_tfo->get_fabric_name(),
 390                 tpg->se_tpg_tfo->tpg_get_tag(tpg), acl->queue_depth,
 391                 tpg->se_tpg_tfo->get_fabric_name(), acl->initiatorname);
 392
 393         kfree(acl);
 394 }
 395
 396 /*      core_tpg_set_initiator_node_queue_depth():
 397  *
 398  *
 399  */
 400 int core_tpg_set_initiator_node_queue_depth(
 401         struct se_node_acl *acl,
 402         u32 queue_depth)
 403 {
 404         LIST_HEAD(sess_list);
 405         struct se_portal_group *tpg = acl->se_tpg;
 406         struct se_session *sess, *sess_tmp;
 407         unsigned long flags;
 408         int rc;
 409
 410         /*
 411          * User has requested to change the queue depth for a Initiator Node.
 412          * Change the value in the Node's struct se_node_acl, and call
 413          * target_set_nacl_queue_depth() to set the new queue depth.
 414          */
 415         target_set_nacl_queue_depth(tpg, acl, queue_depth);
 416
 417         spin_lock_irqsave(&acl->nacl_sess_lock, flags);
 418         list_for_each_entry_safe(sess, sess_tmp, &acl->acl_sess_list,
 419                                  sess_acl_list) {
 420                 if (sess->sess_tearing_down != 0)
 421                         continue;
 422                 if (!target_get_session(sess))
 423                         continue;
 424                 spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
 425
 426                 /*
 427                  * Finally call tpg->se_tpg_tfo->close_session() to force session
 428                  * reinstatement to occur if there is an active session for the
 429                  * $FABRIC_MOD Initiator Node in question.
 430                  */
 431                 rc = tpg->se_tpg_tfo->shutdown_session(sess);
 432                 target_put_session(sess);
 433                 if (!rc) {
 434                         spin_lock_irqsave(&acl->nacl_sess_lock, flags);
 435                         continue;
 436                 }
 437                 target_put_session(sess);
 438                 spin_lock_irqsave(&acl->nacl_sess_lock, flags);
 439         }
 440         spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
 441
 442         pr_debug("Successfully changed queue depth to: %d for Initiator"
 443                 " Node: %s on %s Target Portal Group: %u\n", acl->queue_depth,
 444                 acl->initiatorname, tpg->se_tpg_tfo->get_fabric_name(),
 445                 tpg->se_tpg_tfo->tpg_get_tag(tpg));
 446
 447         return 0;
 448 }
 449 EXPORT_SYMBOL(core_tpg_set_initiator_node_queue_depth);
 450
 451 /*      core_tpg_set_initiator_node_tag():
 452  *
 453  *      Initiator nodeacl tags are not used internally, but may be used by
 454  *      userspace to emulate aliases or groups.
 455  *      Returns length of newly-set tag or -EINVAL.
 456  */
 457 int core_tpg_set_initiator_node_tag(
 458         struct se_portal_group *tpg,
 459         struct se_node_acl *acl,
 460         const char *new_tag)
 461 {
 462         if (strlen(new_tag) >= MAX_ACL_TAG_SIZE)
 463                 return -EINVAL;
 464
 465         if (!strncmp("NULL", new_tag, 4)) {
 466                 acl->acl_tag[0] = '\0';
 467                 return 0;
 468         }
 469
 470         return snprintf(acl->acl_tag, MAX_ACL_TAG_SIZE, "%s", new_tag);
 471 }
 472 EXPORT_SYMBOL(core_tpg_set_initiator_node_tag);
 473
 474 static void core_tpg_lun_ref_release(struct percpu_ref *ref)
 475 {
 476         struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
 477
 478         complete(&lun->lun_ref_comp);
 479 }
 480
 481 int core_tpg_register(
 482         struct se_wwn *se_wwn,
 483         struct se_portal_group *se_tpg,
 484         int proto_id)
 485 {
 486         int ret;
 487
 488         if (!se_tpg)
 489                 return -EINVAL;
 490         /*
 491          * For the typical case where core_tpg_register() is called by a
 492          * fabric driver from target_core_fabric_ops->fabric_make_tpg()
 493          * configfs context, use the original tf_ops pointer already saved
 494          * by target-core in target_fabric_make_wwn().
 495          *
 496          * Otherwise, for special cases like iscsi-target discovery TPGs
 497          * the caller is responsible for setting ->se_tpg_tfo ahead of
 498          * calling core_tpg_register().
 499          */
 500         if (se_wwn)
 501                 se_tpg->se_tpg_tfo = se_wwn->wwn_tf->tf_ops;
 502
 503         if (!se_tpg->se_tpg_tfo) {
 504                 pr_err("Unable to locate se_tpg->se_tpg_tfo pointer\n");
 505                 return -EINVAL;
 506         }
 507
 508         INIT_HLIST_HEAD(&se_tpg->tpg_lun_hlist);
 509         se_tpg->proto_id = proto_id;
 510         se_tpg->se_tpg_wwn = se_wwn;
 511         atomic_set(&se_tpg->tpg_pr_ref_count, 0);
 512         INIT_LIST_HEAD(&se_tpg->acl_node_list);
 513         INIT_LIST_HEAD(&se_tpg->se_tpg_node);
 514         INIT_LIST_HEAD(&se_tpg->tpg_sess_list);
 515         spin_lock_init(&se_tpg->session_lock);
 516         mutex_init(&se_tpg->tpg_lun_mutex);
 517         mutex_init(&se_tpg->acl_node_mutex);
 518
 519         if (se_tpg->proto_id >= 0) {
 520                 se_tpg->tpg_virt_lun0 = core_tpg_alloc_lun(se_tpg, 0);
 521                 if (IS_ERR(se_tpg->tpg_virt_lun0))
 522                         return PTR_ERR(se_tpg->tpg_virt_lun0);
 523
 524                 ret = core_tpg_add_lun(se_tpg, se_tpg->tpg_virt_lun0,
 525                                 TRANSPORT_LUNFLAGS_READ_ONLY, g_lun0_dev);
 526                 if (ret < 0) {
 527                         kfree(se_tpg->tpg_virt_lun0);
 528                         return ret;
 529                 }
 530         }
 531
 532         spin_lock_bh(&tpg_lock);
 533         list_add_tail(&se_tpg->se_tpg_node, &tpg_list);
 534         spin_unlock_bh(&tpg_lock);
 535
 536         pr_debug("TARGET_CORE[%s]: Allocated portal_group for endpoint: %s, "
 537                  "Proto: %d, Portal Tag: %u\n", se_tpg->se_tpg_tfo->get_fabric_name(),
 538                 se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) ?
 539                 se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) : NULL,
 540                 se_tpg->proto_id, se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
 541
 542         return 0;
 543 }
 544 EXPORT_SYMBOL(core_tpg_register);
 545
 546 int core_tpg_deregister(struct se_portal_group *se_tpg)
 547 {
 548         const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 549         struct se_node_acl *nacl, *nacl_tmp;
 550         LIST_HEAD(node_list);
 551
 552         pr_debug("TARGET_CORE[%s]: Deallocating portal_group for endpoint: %s, "
 553                  "Proto: %d, Portal Tag: %u\n", tfo->get_fabric_name(),
 554                 tfo->tpg_get_wwn(se_tpg) ? tfo->tpg_get_wwn(se_tpg) : NULL,
 555                 se_tpg->proto_id, tfo->tpg_get_tag(se_tpg));
 556
 557         spin_lock_bh(&tpg_lock);
 558         list_del(&se_tpg->se_tpg_node);
 559         spin_unlock_bh(&tpg_lock);
 560
 561         while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
 562                 cpu_relax();
 563
 564         mutex_lock(&se_tpg->acl_node_mutex);
 565         list_splice_init(&se_tpg->acl_node_list, &node_list);
 566         mutex_unlock(&se_tpg->acl_node_mutex);
 567         /*
 568          * Release any remaining demo-mode generated se_node_acl that have
 569          * not been released because of TFO->tpg_check_demo_mode_cache() == 1
 570          * in transport_deregister_session().
 571          */
 572         list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) {
 573                 list_del(&nacl->acl_list);
 574
 575                 core_tpg_wait_for_nacl_pr_ref(nacl);
 576                 core_free_device_list_for_node(nacl, se_tpg);
 577                 kfree(nacl);
 578         }
 579
 580         if (se_tpg->proto_id >= 0) {
 581                 core_tpg_remove_lun(se_tpg, se_tpg->tpg_virt_lun0);
 582                 kfree_rcu(se_tpg->tpg_virt_lun0, rcu_head);
 583         }
 584
 585         return 0;
 586 }
 587 EXPORT_SYMBOL(core_tpg_deregister);
 588
 589 struct se_lun *core_tpg_alloc_lun(
 590         struct se_portal_group *tpg,
 591         u64 unpacked_lun)
 592 {
 593         struct se_lun *lun;
 594
 595         lun = kzalloc(sizeof(*lun), GFP_KERNEL);
 596         if (!lun) {
 597                 pr_err("Unable to allocate se_lun memory\n");
 598                 return ERR_PTR(-ENOMEM);
 599         }
 600         lun->unpacked_lun = unpacked_lun;
 601         lun->lun_link_magic = SE_LUN_LINK_MAGIC;
 602         atomic_set(&lun->lun_acl_count, 0);
 603         init_completion(&lun->lun_ref_comp);
 604         INIT_LIST_HEAD(&lun->lun_deve_list);
 605         INIT_LIST_HEAD(&lun->lun_dev_link);
 606         atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
 607         spin_lock_init(&lun->lun_deve_lock);
 608         mutex_init(&lun->lun_tg_pt_md_mutex);
 609         INIT_LIST_HEAD(&lun->lun_tg_pt_gp_link);
 610         spin_lock_init(&lun->lun_tg_pt_gp_lock);
 611         lun->lun_tpg = tpg;
 612
 613         return lun;
 614 }
 615
 616 int core_tpg_add_lun(
 617         struct se_portal_group *tpg,
 618         struct se_lun *lun,
 619         u32 lun_access,
 620         struct se_device *dev)
 621 {
 622         int ret;
 623
 624         ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release, 0,
 625                               GFP_KERNEL);
 626         if (ret < 0)
 627                 goto out;
 628
 629         ret = core_alloc_rtpi(lun, dev);
 630         if (ret)
 631                 goto out_kill_ref;
 632
 633         if (!(dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH) &&
 634             !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 635                 target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);
 636
 637         mutex_lock(&tpg->tpg_lun_mutex);
 638
 639         spin_lock(&dev->se_port_lock);
 640         lun->lun_index = dev->dev_index;
 641         rcu_assign_pointer(lun->lun_se_dev, dev);
 642         dev->export_count++;
 643         list_add_tail(&lun->lun_dev_link, &dev->dev_sep_list);
 644         spin_unlock(&dev->se_port_lock);
 645
 646         if (dev->dev_flags & DF_READ_ONLY)
 647                 lun->lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;
 648         else
 649                 lun->lun_access = lun_access;
 650         if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 651                 hlist_add_head_rcu(&lun->link, &tpg->tpg_lun_hlist);
 652         mutex_unlock(&tpg->tpg_lun_mutex);
 653
 654         return 0;
 655
 656 out_kill_ref:
 657         percpu_ref_exit(&lun->lun_ref);
 658 out:
 659         return ret;
 660 }
 661
 662 void core_tpg_remove_lun(
 663         struct se_portal_group *tpg,
 664         struct se_lun *lun)
 665 {
 666         /*
 667          * rcu_dereference_raw protected by se_lun->lun_group symlink
 668          * reference to se_device->dev_group.
 669          */
 670         struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
 671
 672         core_clear_lun_from_tpg(lun, tpg);
 673         /*
 674          * Wait for any active I/O references to percpu se_lun->lun_ref to
 675          * be released.  Also, se_lun->lun_ref is now used by PR and ALUA
 676          * logic when referencing a remote target port during ALL_TGT_PT=1
 677          * and generating UNIT_ATTENTIONs for ALUA access state transition.
 678          */
 679         transport_clear_lun_ref(lun);
 680
 681         mutex_lock(&tpg->tpg_lun_mutex);
 682         if (lun->lun_se_dev) {
 683                 target_detach_tg_pt_gp(lun);
 684
 685                 spin_lock(&dev->se_port_lock);
 686                 list_del(&lun->lun_dev_link);
 687                 dev->export_count--;
 688                 rcu_assign_pointer(lun->lun_se_dev, NULL);
 689                 spin_unlock(&dev->se_port_lock);
 690         }
 691         if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
 692                 hlist_del_rcu(&lun->link);
 693         mutex_unlock(&tpg->tpg_lun_mutex);
 694
 695         percpu_ref_exit(&lun->lun_ref);
 696 }