target_core_tpg.c

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/*******************************************************************************
 * Filename:  target_core_tpg.c
 *
 * This file contains generic Target Portal Group related functions.
 *
 * Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc.
 * Copyright (c) 2005, 2006, 2007 SBE, Inc.
 * Copyright (c) 2007-2010 Rising Tide Systems
 * Copyright (c) 2008-2010 Linux-iSCSI.org
 *
 * Nicholas A. Bellinger <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 ******************************************************************************/

#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.h>
#include <scsi/scsi_cmnd.h>

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

#include "target_core_internal.h"

extern struct se_device *g_lun0_dev;

static DEFINE_SPINLOCK(tpg_lock);
static LIST_HEAD(tpg_list);

/*  core_clear_initiator_node_from_tpg():
 *
 *
 */
static void core_clear_initiator_node_from_tpg(
    struct se_node_acl *nacl,
    struct se_portal_group *tpg)
{
    int i;
    struct se_dev_entry *deve;
    struct se_lun *lun;

    spin_lock_irq(&nacl->device_list_lock);
    for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
        deve = nacl->device_list[i];

        if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS))
            continue;

        if (!deve->se_lun) {
            pr_err("%s device entries device pointer is"
                " NULL, but Initiator has access.\n",
                tpg->se_tpg_tfo->get_fabric_name());
            continue;
        }

        lun = deve->se_lun;
        spin_unlock_irq(&nacl->device_list_lock);
        core_disable_device_list_for_node(lun, NULL, deve->mapped_lun,
            TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg);

        spin_lock_irq(&nacl->device_list_lock);
    }
    spin_unlock_irq(&nacl->device_list_lock);
}

/*  __core_tpg_get_initiator_node_acl():
 *
 *  spin_lock_bh(&tpg->acl_node_lock); 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;

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

    return NULL;
}

/*  core_tpg_add_node_to_devs():
 *
 *
 */
void core_tpg_add_node_to_devs(
    struct se_node_acl *acl,
    struct se_portal_group *tpg)
{
    int i = 0;
    u32 lun_access = 0;
    struct se_lun *lun;
    struct se_device *dev;

    spin_lock(&tpg->tpg_lun_lock);
    for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
        lun = tpg->tpg_lun_list[i];
        if (lun->lun_status != TRANSPORT_LUN_STATUS_ACTIVE)
            continue;

        spin_unlock(&tpg->tpg_lun_lock);

        dev = lun->lun_se_dev;
        /*
         * 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 = TRANSPORT_LUNFLAGS_READ_WRITE;
        } 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 = TRANSPORT_LUNFLAGS_READ_ONLY;
            else
                lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;
        }

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

        core_enable_device_list_for_node(lun, NULL, lun->unpacked_lun,
                lun_access, acl, tpg);
        spin_lock(&tpg->tpg_lun_lock);
    }
    spin_unlock(&tpg->tpg_lun_lock);
}

/*      core_set_queue_depth_for_node():
 *
 *
 */
static int core_set_queue_depth_for_node(
    struct se_portal_group *tpg,
    struct se_node_acl *acl)
{
    if (!acl->queue_depth) {
        pr_err("Queue depth for %s Initiator Node: %s is 0,"
            "defaulting to 1.\n", tpg->se_tpg_tfo->get_fabric_name(),
            acl->initiatorname);
        acl->queue_depth = 1;
    }

    return 0;
}

void array_free(void *array, int n)
{
    void **a = array;
    int i;

    for (i = 0; i < n; i++)
        kfree(a[i]);
    kfree(a);
}

static void *array_zalloc(int n, size_t size, gfp_t flags)
{
    void **a;
    int i;

    a = kzalloc(n * sizeof(void*), flags);
    if (!a)
        return NULL;
    for (i = 0; i < n; i++) {
        a[i] = kzalloc(size, flags);
        if (!a[i]) {
            array_free(a, n);
            return NULL;
        }
    }
    return a;
}

/*      core_create_device_list_for_node():
 *
 *
 */
static int core_create_device_list_for_node(struct se_node_acl *nacl)
{
    struct se_dev_entry *deve;
    int i;

    nacl->device_list = array_zalloc(TRANSPORT_MAX_LUNS_PER_TPG,
            sizeof(struct se_dev_entry), GFP_KERNEL);
    if (!nacl->device_list) {
        pr_err("Unable to allocate memory for"
            " struct se_node_acl->device_list\n");
        return -ENOMEM;
    }
    for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
        deve = nacl->device_list[i];

        atomic_set(&deve->ua_count, 0);
        atomic_set(&deve->pr_ref_count, 0);
        spin_lock_init(&deve->ua_lock);
        INIT_LIST_HEAD(&deve->alua_port_list);
        INIT_LIST_HEAD(&deve->ua_list);
    }

    return 0;
}

/*  core_tpg_check_initiator_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 =  tpg->se_tpg_tfo->tpg_alloc_fabric_acl(tpg);
    if (!acl)
        return NULL;

    INIT_LIST_HEAD(&acl->acl_list);
    INIT_LIST_HEAD(&acl->acl_sess_list);
    kref_init(&acl->acl_kref);
    init_completion(&acl->acl_free_comp);
    spin_lock_init(&acl->device_list_lock);
    spin_lock_init(&acl->nacl_sess_lock);
    atomic_set(&acl->acl_pr_ref_count, 0);
    acl->queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg);
    snprintf(acl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);
    acl->se_tpg = tpg;
    acl->acl_index = scsi_get_new_index(SCSI_AUTH_INTR_INDEX);
    spin_lock_init(&acl->stats_lock);
    acl->dynamic_node_acl = 1;

    tpg->se_tpg_tfo->set_default_node_attributes(acl);

    if (core_create_device_list_for_node(acl) < 0) {
        tpg->se_tpg_tfo->tpg_release_fabric_acl(tpg, acl);
        return NULL;
    }

    if (core_set_queue_depth_for_node(tpg, acl) < 0) {
        core_free_device_list_for_node(acl, tpg);
        tpg->se_tpg_tfo->tpg_release_fabric_acl(tpg, acl);
        return NULL;
    }
    /*
     * 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);

    spin_lock_irq(&tpg->acl_node_lock);
    list_add_tail(&acl->acl_list, &tpg->acl_node_list);
    tpg->num_node_acls++;
    spin_unlock_irq(&tpg->acl_node_lock);

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

    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();
}

void core_tpg_clear_object_luns(struct se_portal_group *tpg)
{
    int i;
    struct se_lun *lun;

    spin_lock(&tpg->tpg_lun_lock);
    for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
        lun = tpg->tpg_lun_list[i];

        if ((lun->lun_status != TRANSPORT_LUN_STATUS_ACTIVE) ||
            (lun->lun_se_dev == NULL))
            continue;

        spin_unlock(&tpg->tpg_lun_lock);
        core_dev_del_lun(tpg, lun->unpacked_lun);
        spin_lock(&tpg->tpg_lun_lock);
    }
    spin_unlock(&tpg->tpg_lun_lock);
}
EXPORT_SYMBOL(core_tpg_clear_object_luns);

/*  core_tpg_add_initiator_node_acl():
 *
 *
 */
struct se_node_acl *core_tpg_add_initiator_node_acl(
    struct se_portal_group *tpg,
    struct se_node_acl *se_nacl,
    const char *initiatorname,
    u32 queue_depth)
{
    struct se_node_acl *acl = NULL;

    spin_lock_irq(&tpg->acl_node_lock);
    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->get_fabric_name(),
                tpg->se_tpg_tfo->tpg_get_tag(tpg), initiatorname);
            spin_unlock_irq(&tpg->acl_node_lock);
            /*
             * Release the locally allocated struct se_node_acl
             * because * core_tpg_add_initiator_node_acl() returned
             * a pointer to an existing demo mode node ACL.
             */
            if (se_nacl)
                tpg->se_tpg_tfo->tpg_release_fabric_acl(tpg,
                            se_nacl);
            goto done;
        }

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

    if (!se_nacl) {
        pr_err("struct se_node_acl pointer is NULL\n");
        return ERR_PTR(-EINVAL);
    }
    /*
     * For v4.x logic the se_node_acl_s is hanging off a fabric
     * dependent structure allocated via
     * struct target_core_fabric_ops->fabric_make_nodeacl()
     */
    acl = se_nacl;

    INIT_LIST_HEAD(&acl->acl_list);
    INIT_LIST_HEAD(&acl->acl_sess_list);
    kref_init(&acl->acl_kref);
    init_completion(&acl->acl_free_comp);
    spin_lock_init(&acl->device_list_lock);
    spin_lock_init(&acl->nacl_sess_lock);
    atomic_set(&acl->acl_pr_ref_count, 0);
    acl->queue_depth = 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);
    spin_lock_init(&acl->stats_lock);

    tpg->se_tpg_tfo->set_default_node_attributes(acl);

    if (core_create_device_list_for_node(acl) < 0) {
        tpg->se_tpg_tfo->tpg_release_fabric_acl(tpg, acl);
        return ERR_PTR(-ENOMEM);
    }

    if (core_set_queue_depth_for_node(tpg, acl) < 0) {
        core_free_device_list_for_node(acl, tpg);
        tpg->se_tpg_tfo->tpg_release_fabric_acl(tpg, acl);
        return ERR_PTR(-EINVAL);
    }

    spin_lock_irq(&tpg->acl_node_lock);
    list_add_tail(&acl->acl_list, &tpg->acl_node_list);
    tpg->num_node_acls++;
    spin_unlock_irq(&tpg->acl_node_lock);

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

    return acl;
}
EXPORT_SYMBOL(core_tpg_add_initiator_node_acl);

/*  core_tpg_del_initiator_node_acl():
 *
 *
 */
int core_tpg_del_initiator_node_acl(
    struct se_portal_group *tpg,
    struct se_node_acl *acl,
    int force)
{
    LIST_HEAD(sess_list);
    struct se_session *sess, *sess_tmp;
    unsigned long flags;
    int rc;

    spin_lock_irq(&tpg->acl_node_lock);
    if (acl->dynamic_node_acl) {
        acl->dynamic_node_acl = 0;
    }
    list_del(&acl->acl_list);
    tpg->num_node_acls--;
    spin_unlock_irq(&tpg->acl_node_lock);

    spin_lock_irqsave(&acl->nacl_sess_lock, flags);
    acl->acl_stop = 1;

    list_for_each_entry_safe(sess, sess_tmp, &acl->acl_sess_list,
                sess_acl_list) {
        if (sess->sess_tearing_down != 0)
            continue;

        target_get_session(sess);
        list_move(&sess->sess_acl_list, &sess_list);
    }
    spin_unlock_irqrestore(&acl->nacl_sess_lock, flags);

    list_for_each_entry_safe(sess, sess_tmp, &sess_list, sess_acl_list) {
        list_del(&sess->sess_acl_list);

        rc = tpg->se_tpg_tfo->shutdown_session(sess);
        target_put_session(sess);
        if (!rc)
            continue;
        target_put_session(sess);
    }
    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_clear_initiator_node_from_tpg(acl, tpg);
    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->get_fabric_name(),
        tpg->se_tpg_tfo->tpg_get_tag(tpg), acl->queue_depth,
        tpg->se_tpg_tfo->get_fabric_name(), acl->initiatorname);

    return 0;
}
EXPORT_SYMBOL(core_tpg_del_initiator_node_acl);

/*  core_tpg_set_initiator_node_queue_depth():
 *
 *
 */
int core_tpg_set_initiator_node_queue_depth(
    struct se_portal_group *tpg,
    unsigned char *initiatorname,
    u32 queue_depth,
    int force)
{
    struct se_session *sess, *init_sess = NULL;
    struct se_node_acl *acl;
    unsigned long flags;
    int dynamic_acl = 0;

    spin_lock_irq(&tpg->acl_node_lock);
    acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
    if (!acl) {
        pr_err("Access Control List entry for %s Initiator"
            " Node %s does not exists for TPG %hu, ignoring"
            " request.\n", tpg->se_tpg_tfo->get_fabric_name(),
            initiatorname, tpg->se_tpg_tfo->tpg_get_tag(tpg));
        spin_unlock_irq(&tpg->acl_node_lock);
        return -ENODEV;
    }
    if (acl->dynamic_node_acl) {
        acl->dynamic_node_acl = 0;
        dynamic_acl = 1;
    }
    spin_unlock_irq(&tpg->acl_node_lock);

    spin_lock_irqsave(&tpg->session_lock, flags);
    list_for_each_entry(sess, &tpg->tpg_sess_list, sess_list) {
        if (sess->se_node_acl != acl)
            continue;

        if (!force) {
            pr_err("Unable to change queue depth for %s"
                " Initiator Node: %s while session is"
                " operational.  To forcefully change the queue"
                " depth and force session reinstatement"
                " use the \"force=1\" parameter.\n",
                tpg->se_tpg_tfo->get_fabric_name(), initiatorname);
            spin_unlock_irqrestore(&tpg->session_lock, flags);

            spin_lock_irq(&tpg->acl_node_lock);
            if (dynamic_acl)
                acl->dynamic_node_acl = 1;
            spin_unlock_irq(&tpg->acl_node_lock);
            return -EEXIST;
        }
        /*
         * Determine if the session needs to be closed by our context.
         */
        if (!tpg->se_tpg_tfo->shutdown_session(sess))
            continue;

        init_sess = sess;
        break;
    }

    /*
     * 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
     * core_set_queue_depth_for_node() to add the requested queue depth.
     *
     * Finally call  tpg->se_tpg_tfo->close_session() to force session
     * reinstatement to occur if there is an active session for the
     * $FABRIC_MOD Initiator Node in question.
     */
    acl->queue_depth = queue_depth;

    if (core_set_queue_depth_for_node(tpg, acl) < 0) {
        spin_unlock_irqrestore(&tpg->session_lock, flags);
        /*
         * Force session reinstatement if
         * core_set_queue_depth_for_node() failed, because we assume
         * the $FABRIC_MOD has already the set session reinstatement
         * bit from tpg->se_tpg_tfo->shutdown_session() called above.
         */
        if (init_sess)
            tpg->se_tpg_tfo->close_session(init_sess);

        spin_lock_irq(&tpg->acl_node_lock);
        if (dynamic_acl)
            acl->dynamic_node_acl = 1;
        spin_unlock_irq(&tpg->acl_node_lock);
        return -EINVAL;
    }
    spin_unlock_irqrestore(&tpg->session_lock, flags);
    /*
     * If the $FABRIC_MOD session for the Initiator Node ACL exists,
     * forcefully shutdown the $FABRIC_MOD session/nexus.
     */
    if (init_sess)
        tpg->se_tpg_tfo->close_session(init_sess);

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

    spin_lock_irq(&tpg->acl_node_lock);
    if (dynamic_acl)
        acl->dynamic_node_acl = 1;
    spin_unlock_irq(&tpg->acl_node_lock);

    return 0;
}
EXPORT_SYMBOL(core_tpg_set_initiator_node_queue_depth);

static int core_tpg_setup_virtual_lun0(struct se_portal_group *se_tpg)
{
    /* Set in core_dev_setup_virtual_lun0() */
    struct se_device *dev = g_lun0_dev;
    struct se_lun *lun = &se_tpg->tpg_virt_lun0;
    u32 lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;
    int ret;

    lun->unpacked_lun = 0;
    lun->lun_status = TRANSPORT_LUN_STATUS_FREE;
    atomic_set(&lun->lun_acl_count, 0);
    init_completion(&lun->lun_shutdown_comp);
    INIT_LIST_HEAD(&lun->lun_acl_list);
    INIT_LIST_HEAD(&lun->lun_cmd_list);
    spin_lock_init(&lun->lun_acl_lock);
    spin_lock_init(&lun->lun_cmd_lock);
    spin_lock_init(&lun->lun_sep_lock);

    ret = core_tpg_post_addlun(se_tpg, lun, lun_access, dev);
    if (ret < 0)
        return ret;

    return 0;
}

static void core_tpg_release_virtual_lun0(struct se_portal_group *se_tpg)
{
    struct se_lun *lun = &se_tpg->tpg_virt_lun0;

    core_tpg_post_dellun(se_tpg, lun);
}

int core_tpg_register(
    struct target_core_fabric_ops *tfo,
    struct se_wwn *se_wwn,
    struct se_portal_group *se_tpg,
    void *tpg_fabric_ptr,
    int se_tpg_type)
{
    struct se_lun *lun;
    u32 i;

    se_tpg->tpg_lun_list = array_zalloc(TRANSPORT_MAX_LUNS_PER_TPG,
            sizeof(struct se_lun), GFP_KERNEL);
    if (!se_tpg->tpg_lun_list) {
        pr_err("Unable to allocate struct se_portal_group->"
                "tpg_lun_list\n");
        return -ENOMEM;
    }

    for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
        lun = se_tpg->tpg_lun_list[i];
        lun->unpacked_lun = i;
        lun->lun_status = TRANSPORT_LUN_STATUS_FREE;
        atomic_set(&lun->lun_acl_count, 0);
        init_completion(&lun->lun_shutdown_comp);
        INIT_LIST_HEAD(&lun->lun_acl_list);
        INIT_LIST_HEAD(&lun->lun_cmd_list);
        spin_lock_init(&lun->lun_acl_lock);
        spin_lock_init(&lun->lun_cmd_lock);
        spin_lock_init(&lun->lun_sep_lock);
    }

    se_tpg->se_tpg_type = se_tpg_type;
    se_tpg->se_tpg_fabric_ptr = tpg_fabric_ptr;
    se_tpg->se_tpg_tfo = tfo;
    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->se_tpg_node);
    INIT_LIST_HEAD(&se_tpg->tpg_sess_list);
    spin_lock_init(&se_tpg->acl_node_lock);
    spin_lock_init(&se_tpg->session_lock);
    spin_lock_init(&se_tpg->tpg_lun_lock);

    if (se_tpg->se_tpg_type == TRANSPORT_TPG_TYPE_NORMAL) {
        if (core_tpg_setup_virtual_lun0(se_tpg) < 0) {
            kfree(se_tpg);
            return -ENOMEM;
        }
    }

    spin_lock_bh(&tpg_lock);
    list_add_tail(&se_tpg->se_tpg_node, &tpg_list);
    spin_unlock_bh(&tpg_lock);

    pr_debug("TARGET_CORE[%s]: Allocated %s struct se_portal_group for"
        " endpoint: %s, Portal Tag: %u\n", tfo->get_fabric_name(),
        (se_tpg->se_tpg_type == TRANSPORT_TPG_TYPE_NORMAL) ?
        "Normal" : "Discovery", (tfo->tpg_get_wwn(se_tpg) == NULL) ?
        "None" : tfo->tpg_get_wwn(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)
{
    struct se_node_acl *nacl, *nacl_tmp;

    pr_debug("TARGET_CORE[%s]: Deallocating %s struct se_portal_group"
        " for endpoint: %s Portal Tag %u\n",
        (se_tpg->se_tpg_type == TRANSPORT_TPG_TYPE_NORMAL) ?
        "Normal" : "Discovery", se_tpg->se_tpg_tfo->get_fabric_name(),
        se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
        se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));

    spin_lock_bh(&tpg_lock);
    list_del(&se_tpg->se_tpg_node);
    spin_unlock_bh(&tpg_lock);

    while (atomic_read(&se_tpg->tpg_pr_ref_count) != 0)
        cpu_relax();
    /*
     * 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().
     */
    spin_lock_irq(&se_tpg->acl_node_lock);
    list_for_each_entry_safe(nacl, nacl_tmp, &se_tpg->acl_node_list,
            acl_list) {
        list_del(&nacl->acl_list);
        se_tpg->num_node_acls--;
        spin_unlock_irq(&se_tpg->acl_node_lock);

        core_tpg_wait_for_nacl_pr_ref(nacl);
        core_free_device_list_for_node(nacl, se_tpg);
        se_tpg->se_tpg_tfo->tpg_release_fabric_acl(se_tpg, nacl);

        spin_lock_irq(&se_tpg->acl_node_lock);
    }
    spin_unlock_irq(&se_tpg->acl_node_lock);

    if (se_tpg->se_tpg_type == TRANSPORT_TPG_TYPE_NORMAL)
        core_tpg_release_virtual_lun0(se_tpg);

    se_tpg->se_tpg_fabric_ptr = NULL;
    array_free(se_tpg->tpg_lun_list, TRANSPORT_MAX_LUNS_PER_TPG);
    return 0;
}
EXPORT_SYMBOL(core_tpg_deregister);

struct se_lun *core_tpg_pre_addlun(
    struct se_portal_group *tpg,
    u32 unpacked_lun)
{
    struct se_lun *lun;

    if (unpacked_lun > (TRANSPORT_MAX_LUNS_PER_TPG-1)) {
        pr_err("%s LUN: %u exceeds TRANSPORT_MAX_LUNS_PER_TPG"
            "-1: %u for Target Portal Group: %u\n",
            tpg->se_tpg_tfo->get_fabric_name(),
            unpacked_lun, TRANSPORT_MAX_LUNS_PER_TPG-1,
            tpg->se_tpg_tfo->tpg_get_tag(tpg));
        return ERR_PTR(-EOVERFLOW);
    }

    spin_lock(&tpg->tpg_lun_lock);
    lun = tpg->tpg_lun_list[unpacked_lun];
    if (lun->lun_status == TRANSPORT_LUN_STATUS_ACTIVE) {
        pr_err("TPG Logical Unit Number: %u is already active"
            " on %s Target Portal Group: %u, ignoring request.\n",
            unpacked_lun, tpg->se_tpg_tfo->get_fabric_name(),
            tpg->se_tpg_tfo->tpg_get_tag(tpg));
        spin_unlock(&tpg->tpg_lun_lock);
        return ERR_PTR(-EINVAL);
    }
    spin_unlock(&tpg->tpg_lun_lock);

    return lun;
}

int core_tpg_post_addlun(
    struct se_portal_group *tpg,
    struct se_lun *lun,
    u32 lun_access,
    void *lun_ptr)
{
    int ret;

    ret = core_dev_export(lun_ptr, tpg, lun);
    if (ret < 0)
        return ret;

    spin_lock(&tpg->tpg_lun_lock);
    lun->lun_access = lun_access;
    lun->lun_status = TRANSPORT_LUN_STATUS_ACTIVE;
    spin_unlock(&tpg->tpg_lun_lock);

    return 0;
}

static void core_tpg_shutdown_lun(
    struct se_portal_group *tpg,
    struct se_lun *lun)
{
    core_clear_lun_from_tpg(lun, tpg);
    transport_clear_lun_from_sessions(lun);
}

struct se_lun *core_tpg_pre_dellun(
    struct se_portal_group *tpg,
    u32 unpacked_lun)
{
    struct se_lun *lun;

    if (unpacked_lun > (TRANSPORT_MAX_LUNS_PER_TPG-1)) {
        pr_err("%s LUN: %u exceeds TRANSPORT_MAX_LUNS_PER_TPG"
            "-1: %u for Target Portal Group: %u\n",
            tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
            TRANSPORT_MAX_LUNS_PER_TPG-1,
            tpg->se_tpg_tfo->tpg_get_tag(tpg));
        return ERR_PTR(-EOVERFLOW);
    }

    spin_lock(&tpg->tpg_lun_lock);
    lun = tpg->tpg_lun_list[unpacked_lun];
    if (lun->lun_status != TRANSPORT_LUN_STATUS_ACTIVE) {
        pr_err("%s Logical Unit Number: %u is not active on"
            " Target Portal Group: %u, ignoring request.\n",
            tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
            tpg->se_tpg_tfo->tpg_get_tag(tpg));
        spin_unlock(&tpg->tpg_lun_lock);
        return ERR_PTR(-ENODEV);
    }
    spin_unlock(&tpg->tpg_lun_lock);

    return lun;
}

int core_tpg_post_dellun(
    struct se_portal_group *tpg,
    struct se_lun *lun)
{
    core_tpg_shutdown_lun(tpg, lun);

    core_dev_unexport(lun->lun_se_dev, tpg, lun);

    spin_lock(&tpg->tpg_lun_lock);
    lun->lun_status = TRANSPORT_LUN_STATUS_FREE;
    spin_unlock(&tpg->tpg_lun_lock);

    return 0;
}