Quelle  target_core_tpg.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
 * Filename:  target_core_tpg.c
 *
 * This file contains generic Target Portal Group related functions.
 *
 * (c) Copyright 2002-2013 Datera, Inc.
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 ******************************************************************************/

#include <linux/net.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/in.h>
#include <linux/export.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <scsi/scsi_proto.h>

#include <target/target_core_base.h>
#include <target/target_core_backend.h>
#include <target/target_core_fabric.h>

#include "target_core_internal.h"
#include "target_core_alua.h"
#include "target_core_pr.h"
#include "target_core_ua.h"

extern struct se_device *g_lun0_dev;
static DEFINE_XARRAY_ALLOC(tpg_xa);

/* __core_tpg_get_initiator_node_acl():
 *
 * mutex_lock(&tpg->acl_node_mutex); must be held when calling
 */
struct se_node_acl *__core_tpg_get_initiator_node_acl(
 struct se_portal_group *tpg,
 const char *initiatorname)
{
 struct se_node_acl *acl;

 list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
  if (!strcmp(acl->initiatorname, initiatorname))
   return acl;
 }

 return NULL;
}

/* core_tpg_get_initiator_node_acl():
 *
 *
 */
struct se_node_acl *core_tpg_get_initiator_node_acl(
 struct se_portal_group *tpg,
 unsigned char *initiatorname)
{
 struct se_node_acl *acl;
 /*
 * Obtain se_node_acl->acl_kref using fabric driver provided
 * initiatorname[] during node acl endpoint lookup driven by
 * new se_session login.
 *
 * The reference is held until se_session shutdown -> release
 * occurs via fabric driver invoked transport_deregister_session()
 * or transport_free_session() code.
 */
 mutex_lock(&tpg->acl_node_mutex);
 acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
 if (acl) {
  if (!kref_get_unless_zero(&acl->acl_kref))
   acl = NULL;
 }
 mutex_unlock(&tpg->acl_node_mutex);

 return acl;
}
EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);

void core_allocate_nexus_loss_ua(
 struct se_node_acl *nacl)
{
 struct se_dev_entry *deve;

 if (!nacl)
  return;

 rcu_read_lock();
 hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link)
  core_scsi3_ua_allocate(deve, 0x29,
   ASCQ_29H_NEXUS_LOSS_OCCURRED);
 rcu_read_unlock();
}
EXPORT_SYMBOL(core_allocate_nexus_loss_ua);

/* core_tpg_add_node_to_devs():
 *
 *
 */
void core_tpg_add_node_to_devs(
 struct se_node_acl *acl,
 struct se_portal_group *tpg,
 struct se_lun *lun_orig)
{
 bool lun_access_ro = true;
 struct se_lun *lun;
 struct se_device *dev;

 mutex_lock(&tpg->tpg_lun_mutex);
 hlist_for_each_entry_rcu(lun, &tpg->tpg_lun_hlist, link) {
  if (lun_orig && lun != lun_orig)
   continue;

  dev = rcu_dereference_check(lun->lun_se_dev,
         lockdep_is_held(&tpg->tpg_lun_mutex));
  /*
 * By default in LIO-Target $FABRIC_MOD,
 * demo_mode_write_protect is ON, or READ_ONLY;
 */
  if (!tpg->se_tpg_tfo->tpg_check_demo_mode_write_protect(tpg)) {
   lun_access_ro = false;
  } else {
   /*
 * Allow only optical drives to issue R/W in default RO
 * demo mode.
 */
   if (dev->transport->get_device_type(dev) == TYPE_DISK)
    lun_access_ro = true;
   else
    lun_access_ro = false;
  }

  pr_debug("TARGET_CORE[%s]->TPG[%u]_LUN[%llu] - Adding %s"
   " access for LUN in Demo Mode\n",
   tpg->se_tpg_tfo->fabric_name,
   tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
   lun_access_ro ? "READ-ONLY" : "READ-WRITE");

  core_enable_device_list_for_node(lun, NULL, lun->unpacked_lun,
       lun_access_ro, acl, tpg);
  /*
 * Check to see if there are any existing persistent reservation
 * APTPL pre-registrations that need to be enabled for this dynamic
 * LUN ACL now..
 */
  core_scsi3_check_aptpl_registration(dev, tpg, lun, acl,
          lun->unpacked_lun);
 }
 mutex_unlock(&tpg->tpg_lun_mutex);
}

static void
target_set_nacl_queue_depth(struct se_portal_group *tpg,
       struct se_node_acl *acl, u32 queue_depth)
{
 acl->queue_depth = queue_depth;

 if (!acl->queue_depth) {
  pr_warn("Queue depth for %s Initiator Node: %s is 0,"
   "defaulting to 1.\n", tpg->se_tpg_tfo->fabric_name,
   acl->initiatorname);
  acl->queue_depth = 1;
 }
}

static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg,
  const unsigned char *initiatorname)
{
 struct se_node_acl *acl;
 u32 queue_depth;

 acl = kzalloc(max(sizeof(*acl), tpg->se_tpg_tfo->node_acl_size),
   GFP_KERNEL);
 if (!acl)
  return NULL;

 INIT_LIST_HEAD(&acl->acl_list);
 INIT_LIST_HEAD(&acl->acl_sess_list);
 INIT_HLIST_HEAD(&acl->lun_entry_hlist);
 kref_init(&acl->acl_kref);
 init_completion(&acl->acl_free_comp);
 spin_lock_init(&acl->nacl_sess_lock);
 mutex_init(&acl->lun_entry_mutex);
 atomic_set(&acl->acl_pr_ref_count, 0);

 if (tpg->se_tpg_tfo->tpg_get_default_depth)
  queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
 else
  queue_depth = 1;
 target_set_nacl_queue_depth(tpg, acl, queue_depth);

 snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
 acl->se_tpg = tpg;
 acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);

 tpg->se_tpg_tfo->set_default_node_attributes(acl);

 return acl;
}

static void target_add_node_acl(struct se_node_acl *acl)
{
 struct se_portal_group *tpg = acl->se_tpg;

 mutex_lock(&tpg->acl_node_mutex);
 list_add_tail(&acl->acl_list, &tpg->acl_node_list);
 mutex_unlock(&tpg->acl_node_mutex);

 pr_debug("%s_TPG[%hu] - Added %s ACL with TCQ Depth: %d for %s"
  " Initiator Node: %s\n",
  tpg->se_tpg_tfo->fabric_name,
  tpg->se_tpg_tfo->tpg_get_tag(tpg),
  acl->dynamic_node_acl ? "DYNAMIC" : "",
  acl->queue_depth,
  tpg->se_tpg_tfo->fabric_name,
  acl->initiatorname);
}

bool target_tpg_has_node_acl(struct se_portal_group *tpg,
        const char *initiatorname)
{
 struct se_node_acl *acl;
 bool found = false;

 mutex_lock(&tpg->acl_node_mutex);
 list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
  if (!strcmp(acl->initiatorname, initiatorname)) {
   found = true;
   break;
  }
 }
 mutex_unlock(&tpg->acl_node_mutex);

 return found;
}
EXPORT_SYMBOL(target_tpg_has_node_acl);

struct se_node_acl *core_tpg_check_initiator_node_acl(
 struct se_portal_group *tpg,
 unsigned char *initiatorname)
{
 struct se_node_acl *acl;

 acl = core_tpg_get_initiator_node_acl(tpg, initiatorname);
 if (acl)
  return acl;

 if (!tpg->se_tpg_tfo->tpg_check_demo_mode(tpg))
  return NULL;

 acl = target_alloc_node_acl(tpg, initiatorname);
 if (!acl)
  return NULL;
 /*
 * When allocating a dynamically generated node_acl, go ahead
 * and take the extra kref now before returning to the fabric
 * driver caller.
 *
 * Note this reference will be released at session shutdown
 * time within transport_free_session() code.
 */
 kref_get(&acl->acl_kref);
 acl->dynamic_node_acl = 1;

 /*
 * Here we only create demo-mode MappedLUNs from the active
 * TPG LUNs if the fabric is not explicitly asking for
 * tpg_check_demo_mode_login_only() == 1.
 */
 if ((tpg->se_tpg_tfo->tpg_check_demo_mode_login_only == NULL) ||
     (tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg) != 1))
  core_tpg_add_node_to_devs(acl, tpg, NULL);

 target_add_node_acl(acl);
 return acl;
}
EXPORT_SYMBOL(core_tpg_check_initiator_node_acl);

void core_tpg_wait_for_nacl_pr_ref(struct se_node_acl *nacl)
{
 while (atomic_read(&nacl->acl_pr_ref_count) != 0)
  cpu_relax();
}

struct se_node_acl *core_tpg_add_initiator_node_acl(
 struct se_portal_group *tpg,
 const char *initiatorname)
{
 struct se_node_acl *acl;

 mutex_lock(&tpg->acl_node_mutex);
 acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
 if (acl) {
  if (acl->dynamic_node_acl) {
   acl->dynamic_node_acl = 0;
   pr_debug("%s_TPG[%u] - Replacing dynamic ACL"
    " for %s\n", tpg->se_tpg_tfo->fabric_name,
    tpg->se_tpg_tfo->tpg_get_tag(tpg), initiatorname);
   mutex_unlock(&tpg->acl_node_mutex);
   return acl;
  }

  pr_err("ACL entry for %s Initiator"
   " Node %s already exists for TPG %u, ignoring"
   " request.\n",  tpg->se_tpg_tfo->fabric_name,
   initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
  mutex_unlock(&tpg->acl_node_mutex);
  return ERR_PTR(-EEXIST);
 }
 mutex_unlock(&tpg->acl_node_mutex);

 acl = target_alloc_node_acl(tpg, initiatorname);
 if (!acl)
  return ERR_PTR(-ENOMEM);

 target_add_node_acl(acl);
 return acl;
}

static void target_shutdown_sessions(struct se_node_acl *acl)
{
 struct se_session *sess;
 unsigned long flags;

restart:
 spin_lock_irqsave(&acl->nacl_sess_lock, flags);
 list_for_each_entry(sess, &acl->acl_sess_list, sess_acl_list) {
  if (sess->cmd_cnt && atomic_read(&sess->cmd_cnt->stopped))
   continue;

  list_del_init(&sess->sess_acl_list);
  spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);

  if (acl->se_tpg->se_tpg_tfo->close_session)
   acl->se_tpg->se_tpg_tfo->close_session(sess);
  goto restart;
 }
 spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);
}

void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
{
 struct se_portal_group *tpg = acl->se_tpg;

 mutex_lock(&tpg->acl_node_mutex);
 if (acl->dynamic_node_acl)
  acl->dynamic_node_acl = 0;
 list_del_init(&acl->acl_list);
 mutex_unlock(&tpg->acl_node_mutex);

 target_shutdown_sessions(acl);

 target_put_nacl(acl);
 /*
 * Wait for last target_put_nacl() to complete in target_complete_nacl()
 * for active fabric session transport_deregister_session() callbacks.
 */
 wait_for_completion(&acl->acl_free_comp);

 core_tpg_wait_for_nacl_pr_ref(acl);
 core_free_device_list_for_node(acl, tpg);

 pr_debug("%s_TPG[%hu] - Deleted ACL with TCQ Depth: %d for %s"
  " Initiator Node: %s\n", tpg->se_tpg_tfo->fabric_name,
  tpg->se_tpg_tfo->tpg_get_tag(tpg), acl->queue_depth,
  tpg->se_tpg_tfo->fabric_name, acl->initiatorname);

 kfree(acl);
}

/* core_tpg_set_initiator_node_queue_depth():
 *
 *
 */
int core_tpg_set_initiator_node_queue_depth(
 struct se_node_acl *acl,
 u32 queue_depth)
{
 struct se_portal_group *tpg = acl->se_tpg;

 /*
 * Allow the setting of se_node_acl queue_depth to be idempotent,
 * and not force a session shutdown event if the value is not
 * changing.
 */
 if (acl->queue_depth == queue_depth)
  return 0;
 /*
 * User has requested to change the queue depth for a Initiator Node.
 * Change the value in the Node's struct se_node_acl, and call
 * target_set_nacl_queue_depth() to set the new queue depth.
 */
 target_set_nacl_queue_depth(tpg, acl, queue_depth);

 /*
 * Shutdown all pending sessions to force session reinstatement.
 */
 target_shutdown_sessions(acl);

 pr_debug("Successfully changed queue depth to: %d for Initiator"
  " Node: %s on %s Target Portal Group: %u\n", acl->queue_depth,
  acl->initiatorname, tpg->se_tpg_tfo->fabric_name,
  tpg->se_tpg_tfo->tpg_get_tag(tpg));

 return 0;
}
EXPORT_SYMBOL(core_tpg_set_initiator_node_queue_depth);

/* core_tpg_set_initiator_node_tag():
 *
 * Initiator nodeacl tags are not used internally, but may be used by
 * userspace to emulate aliases or groups.
 * Returns length of newly-set tag or -EINVAL.
 */
int core_tpg_set_initiator_node_tag(
 struct se_portal_group *tpg,
 struct se_node_acl *acl,
 const char *new_tag)
{
 if (strlen(new_tag) >= MAX_ACL_TAG_SIZE)
  return -EINVAL;

 if (!strncmp("NULL", new_tag, 4)) {
  acl->acl_tag[0] = '\0';
  return 0;
 }

 return snprintf(acl->acl_tag, MAX_ACL_TAG_SIZE, "%s", new_tag);
}
EXPORT_SYMBOL(core_tpg_set_initiator_node_tag);

static void core_tpg_lun_ref_release(struct percpu_ref *ref)
{
 struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);

 complete(&lun->lun_shutdown_comp);
}

static int target_tpg_register_rtpi(struct se_portal_group *se_tpg)
{
 u32 val;
 int ret;

 if (se_tpg->rtpi_manual) {
  ret = xa_insert(&tpg_xa, se_tpg->tpg_rtpi, se_tpg, GFP_KERNEL);
  if (ret) {
   pr_info("%s_TPG[%hu] - Can not set RTPI %#x, it is already busy",
    se_tpg->se_tpg_tfo->fabric_name,
    se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg),
    se_tpg->tpg_rtpi);
   return -EINVAL;
  }
 } else {
  ret = xa_alloc(&tpg_xa, &val, se_tpg,
          XA_LIMIT(1, USHRT_MAX), GFP_KERNEL);
  if (!ret)
   se_tpg->tpg_rtpi = val;
 }

 return ret;
}

static void target_tpg_deregister_rtpi(struct se_portal_group *se_tpg)
{
 if (se_tpg->tpg_rtpi && se_tpg->enabled)
  xa_erase(&tpg_xa, se_tpg->tpg_rtpi);
}

int target_tpg_enable(struct se_portal_group *se_tpg)
{
 int ret;

 ret = target_tpg_register_rtpi(se_tpg);
 if (ret)
  return ret;

 ret = se_tpg->se_tpg_tfo->fabric_enable_tpg(se_tpg, true);
 if (ret) {
  target_tpg_deregister_rtpi(se_tpg);
  return ret;
 }

 se_tpg->enabled = true;

 return 0;
}

int target_tpg_disable(struct se_portal_group *se_tpg)
{
 int ret;

 target_tpg_deregister_rtpi(se_tpg);

 ret = se_tpg->se_tpg_tfo->fabric_enable_tpg(se_tpg, false);
 if (!ret)
  se_tpg->enabled = false;

 return ret;
}

/* Does not change se_wwn->priv. */
int core_tpg_register(
 struct se_wwn *se_wwn,
 struct se_portal_group *se_tpg,
 int proto_id)
{
 int ret;

 if (!se_tpg)
  return -EINVAL;
 /*
 * For the typical case where core_tpg_register() is called by a
 * fabric driver from target_core_fabric_ops->fabric_make_tpg()
 * configfs context, use the original tf_ops pointer already saved
 * by target-core in target_fabric_make_wwn().
 *
 * Otherwise, for special cases like iscsi-target discovery TPGs
 * the caller is responsible for setting ->se_tpg_tfo ahead of
 * calling core_tpg_register().
 */
 if (se_wwn)
  se_tpg->se_tpg_tfo = se_wwn->wwn_tf->tf_ops;

 if (!se_tpg->se_tpg_tfo) {
  pr_err("Unable to locate se_tpg->se_tpg_tfo pointer\n");
  return -EINVAL;
 }

 INIT_HLIST_HEAD(&se_tpg->tpg_lun_hlist);
 se_tpg->proto_id = proto_id;
 se_tpg->se_tpg_wwn = se_wwn;
 atomic_set(&se_tpg->tpg_pr_ref_count, 0);
 INIT_LIST_HEAD(&se_tpg->acl_node_list);
 INIT_LIST_HEAD(&se_tpg->tpg_sess_list);
 spin_lock_init(&se_tpg->session_lock);
 mutex_init(&se_tpg->tpg_lun_mutex);
 mutex_init(&se_tpg->acl_node_mutex);

 if (se_tpg->proto_id >= 0) {
  se_tpg->tpg_virt_lun0 = core_tpg_alloc_lun(se_tpg, 0);
  if (IS_ERR(se_tpg->tpg_virt_lun0))
   return PTR_ERR(se_tpg->tpg_virt_lun0);

  ret = core_tpg_add_lun(se_tpg, se_tpg->tpg_virt_lun0,
    true, g_lun0_dev);
  if (ret < 0) {
   kfree(se_tpg->tpg_virt_lun0);
   return ret;
  }
 }

 pr_debug("TARGET_CORE[%s]: Allocated portal_group for endpoint: %s, "
   "Proto: %d, Portal Tag: %u\n", se_tpg->se_tpg_tfo->fabric_name,
  se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) ?
  se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg) : NULL,
  se_tpg->proto_id, se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));

 return 0;
}
EXPORT_SYMBOL(core_tpg_register);

int core_tpg_deregister(struct se_portal_group *se_tpg)
{
 const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
 struct se_node_acl *nacl, *nacl_tmp;
 LIST_HEAD(node_list);

 pr_debug("TARGET_CORE[%s]: Deallocating portal_group for endpoint: %s, "
   "Proto: %d, Portal Tag: %u\n", tfo->fabric_name,
  tfo->tpg_get_wwn(se_tpg) ? tfo->tpg_get_wwn(se_tpg) : NULL,
  se_tpg->proto_id, tfo->tpg_get_tag(se_tpg));

 while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
  cpu_relax();

 mutex_lock(&se_tpg->acl_node_mutex);
 list_splice_init(&se_tpg->acl_node_list, &node_list);
 mutex_unlock(&se_tpg->acl_node_mutex);
 /*
 * Release any remaining demo-mode generated se_node_acl that have
 * not been released because of TFO->tpg_check_demo_mode_cache() == 1
 * in transport_deregister_session().
 */
 list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) {
  list_del_init(&nacl->acl_list);

  core_tpg_wait_for_nacl_pr_ref(nacl);
  core_free_device_list_for_node(nacl, se_tpg);
  kfree(nacl);
 }

 if (se_tpg->proto_id >= 0) {
  core_tpg_remove_lun(se_tpg, se_tpg->tpg_virt_lun0);
  kfree_rcu(se_tpg->tpg_virt_lun0, rcu_head);
 }

 target_tpg_deregister_rtpi(se_tpg);

 return 0;
}
EXPORT_SYMBOL(core_tpg_deregister);

struct se_lun *core_tpg_alloc_lun(
 struct se_portal_group *tpg,
 u64 unpacked_lun)
{
 struct se_lun *lun;

 lun = kzalloc(sizeof(*lun), GFP_KERNEL);
 if (!lun) {
  pr_err("Unable to allocate se_lun memory\n");
  return ERR_PTR(-ENOMEM);
 }
 lun->unpacked_lun = unpacked_lun;
 atomic_set(&lun->lun_acl_count, 0);
 init_completion(&lun->lun_shutdown_comp);
 INIT_LIST_HEAD(&lun->lun_deve_list);
 INIT_LIST_HEAD(&lun->lun_dev_link);
 atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
 spin_lock_init(&lun->lun_deve_lock);
 mutex_init(&lun->lun_tg_pt_md_mutex);
 INIT_LIST_HEAD(&lun->lun_tg_pt_gp_link);
 spin_lock_init(&lun->lun_tg_pt_gp_lock);
 lun->lun_tpg = tpg;

 return lun;
}

int core_tpg_add_lun(
 struct se_portal_group *tpg,
 struct se_lun *lun,
 bool lun_access_ro,
 struct se_device *dev)
{
 int ret;

 ret = percpu_ref_init(&lun->lun_ref, core_tpg_lun_ref_release, 0,
         GFP_KERNEL);
 if (ret < 0)
  goto out;

 if (!(dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
     !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
  target_attach_tg_pt_gp(lun, dev->t10_alua.default_tg_pt_gp);

 mutex_lock(&tpg->tpg_lun_mutex);

 spin_lock(&dev->se_port_lock);
 lun->lun_index = dev->dev_index;
 rcu_assign_pointer(lun->lun_se_dev, dev);
 dev->export_count++;
 list_add_tail(&lun->lun_dev_link, &dev->dev_sep_list);
 spin_unlock(&dev->se_port_lock);

 if (dev->dev_flags & DF_READ_ONLY)
  lun->lun_access_ro = true;
 else
  lun->lun_access_ro = lun_access_ro;
 if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
  hlist_add_head_rcu(&lun->link, &tpg->tpg_lun_hlist);
 mutex_unlock(&tpg->tpg_lun_mutex);

 return 0;

out:
 return ret;
}

void core_tpg_remove_lun(
 struct se_portal_group *tpg,
 struct se_lun *lun)
{
 /*
 * rcu_dereference_raw protected by se_lun->lun_group symlink
 * reference to se_device->dev_group.
 */
 struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);

 lun->lun_shutdown = true;

 core_clear_lun_from_tpg(lun, tpg);
 /*
 * Wait for any active I/O references to percpu se_lun->lun_ref to
 * be released.  Also, se_lun->lun_ref is now used by PR and ALUA
 * logic when referencing a remote target port during ALL_TGT_PT=1
 * and generating UNIT_ATTENTIONs for ALUA access state transition.
 */
 transport_clear_lun_ref(lun);

 mutex_lock(&tpg->tpg_lun_mutex);
 if (lun->lun_se_dev) {
  target_detach_tg_pt_gp(lun);

  spin_lock(&dev->se_port_lock);
  list_del(&lun->lun_dev_link);
  dev->export_count--;
  rcu_assign_pointer(lun->lun_se_dev, NULL);
  spin_unlock(&dev->se_port_lock);
 }
 if (!(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
  hlist_del_rcu(&lun->link);

 lun->lun_shutdown = false;
 mutex_unlock(&tpg->tpg_lun_mutex);

 percpu_ref_exit(&lun->lun_ref);
}