/*******************************************************************************
 * 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>
 *
 * 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"
#include "target_core_pr.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);
        acl = __core_tpg_get_initiator_node_acl(tpg, initiatorname);
        spin_unlock_irq(&tpg->acl_node_lock);

        return acl;
}
EXPORT_SYMBOL(core_tpg_get_initiator_node_acl);

/*      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);
                /*
                 * 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);
                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);
        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);
                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);

        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);

/*      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_ref_comp);
}

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);
        spin_lock_init(&lun->lun_acl_lock);
        spin_lock_init(&lun->lun_sep_lock);
        init_completion(&lun->lun_ref_comp);

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

        return 0;
}

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_link_magic = SE_LUN_LINK_MAGIC;
                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);
                spin_lock_init(&lun->lun_acl_lock);
                spin_lock_init(&lun->lun_sep_lock);
                init_completion(&lun->lun_ref_comp);
        }

        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) {
                        array_free(se_tpg->tpg_lun_list,
                                   TRANSPORT_MAX_LUNS_PER_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_remove_lun(se_tpg, &se_tpg->tpg_virt_lun0);

        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_alloc_lun(
        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_add_lun(
        struct se_portal_group *tpg,
        struct se_lun *lun,
        u32 lun_access,
        struct se_device *dev)
{
        int ret;

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

        ret = core_dev_export(dev, tpg, lun);
        if (ret < 0) {
                percpu_ref_exit(&lun->lun_ref);
                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;
}

void core_tpg_remove_lun(
        struct se_portal_group *tpg,
        struct se_lun *lun)
{
        core_clear_lun_from_tpg(lun, tpg);
        transport_clear_lun_ref(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);

        percpu_ref_exit(&lun->lun_ref);
}