target_core_device.c

Go to the documentation of this file.

/*******************************************************************************
 * Filename:  target_core_device.c (based on iscsi_target_device.c)
 *
 * This file contains the TCM Virtual Device and Disk Transport
 * agnostic related functions.
 *
 * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
 * Copyright (c) 2005-2006 SBE, Inc.  All Rights Reserved.
 * 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/delay.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/kthread.h>
#include <linux/in.h>
#include <linux/export.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <scsi/scsi.h>
#include <scsi/scsi_device.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"

static void se_dev_start(struct se_device *dev);
static void se_dev_stop(struct se_device *dev);

static struct se_hba *lun0_hba;
static struct se_subsystem_dev *lun0_su_dev;
/* not static, needed by tpg.c */
struct se_device *g_lun0_dev;

int transport_lookup_cmd_lun(struct se_cmd *se_cmd, u32 unpacked_lun)
{
    struct se_lun *se_lun = NULL;
    struct se_session *se_sess = se_cmd->se_sess;
    struct se_device *dev;
    unsigned long flags;

    if (unpacked_lun >= TRANSPORT_MAX_LUNS_PER_TPG) {
        se_cmd->scsi_sense_reason = TCM_NON_EXISTENT_LUN;
        se_cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
        return -ENODEV;
    }

    spin_lock_irqsave(&se_sess->se_node_acl->device_list_lock, flags);
    se_cmd->se_deve = se_sess->se_node_acl->device_list[unpacked_lun];
    if (se_cmd->se_deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS) {
        struct se_dev_entry *deve = se_cmd->se_deve;

        deve->total_cmds++;
        deve->total_bytes += se_cmd->data_length;

        if ((se_cmd->data_direction == DMA_TO_DEVICE) &&
            (deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY)) {
            se_cmd->scsi_sense_reason = TCM_WRITE_PROTECTED;
            se_cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
            pr_err("TARGET_CORE[%s]: Detected WRITE_PROTECTED LUN"
                " Access for 0x%08x\n",
                se_cmd->se_tfo->get_fabric_name(),
                unpacked_lun);
            spin_unlock_irqrestore(&se_sess->se_node_acl->device_list_lock, flags);
            return -EACCES;
        }

        if (se_cmd->data_direction == DMA_TO_DEVICE)
            deve->write_bytes += se_cmd->data_length;
        else if (se_cmd->data_direction == DMA_FROM_DEVICE)
            deve->read_bytes += se_cmd->data_length;

        deve->deve_cmds++;

        se_lun = deve->se_lun;
        se_cmd->se_lun = deve->se_lun;
        se_cmd->pr_res_key = deve->pr_res_key;
        se_cmd->orig_fe_lun = unpacked_lun;
        se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
    }
    spin_unlock_irqrestore(&se_sess->se_node_acl->device_list_lock, flags);

    if (!se_lun) {
        /*
         * Use the se_portal_group->tpg_virt_lun0 to allow for
         * REPORT_LUNS, et al to be returned when no active
         * MappedLUN=0 exists for this Initiator Port.
         */
        if (unpacked_lun != 0) {
            se_cmd->scsi_sense_reason = TCM_NON_EXISTENT_LUN;
            se_cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
            pr_err("TARGET_CORE[%s]: Detected NON_EXISTENT_LUN"
                " Access for 0x%08x\n",
                se_cmd->se_tfo->get_fabric_name(),
                unpacked_lun);
            return -ENODEV;
        }
        /*
         * Force WRITE PROTECT for virtual LUN 0
         */
        if ((se_cmd->data_direction != DMA_FROM_DEVICE) &&
            (se_cmd->data_direction != DMA_NONE)) {
            se_cmd->scsi_sense_reason = TCM_WRITE_PROTECTED;
            se_cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
            return -EACCES;
        }

        se_lun = &se_sess->se_tpg->tpg_virt_lun0;
        se_cmd->se_lun = &se_sess->se_tpg->tpg_virt_lun0;
        se_cmd->orig_fe_lun = 0;
        se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
    }
    /*
     * Determine if the struct se_lun is online.
     * FIXME: Check for LUN_RESET + UNIT Attention
     */
    if (se_dev_check_online(se_lun->lun_se_dev) != 0) {
        se_cmd->scsi_sense_reason = TCM_NON_EXISTENT_LUN;
        se_cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
        return -ENODEV;
    }

    /* Directly associate cmd with se_dev */
    se_cmd->se_dev = se_lun->lun_se_dev;

    /* TODO: get rid of this and use atomics for stats */
    dev = se_lun->lun_se_dev;
    spin_lock_irqsave(&dev->stats_lock, flags);
    dev->num_cmds++;
    if (se_cmd->data_direction == DMA_TO_DEVICE)
        dev->write_bytes += se_cmd->data_length;
    else if (se_cmd->data_direction == DMA_FROM_DEVICE)
        dev->read_bytes += se_cmd->data_length;
    spin_unlock_irqrestore(&dev->stats_lock, flags);

    spin_lock_irqsave(&se_lun->lun_cmd_lock, flags);
    list_add_tail(&se_cmd->se_lun_node, &se_lun->lun_cmd_list);
    spin_unlock_irqrestore(&se_lun->lun_cmd_lock, flags);

    return 0;
}
EXPORT_SYMBOL(transport_lookup_cmd_lun);

int transport_lookup_tmr_lun(struct se_cmd *se_cmd, u32 unpacked_lun)
{
    struct se_dev_entry *deve;
    struct se_lun *se_lun = NULL;
    struct se_session *se_sess = se_cmd->se_sess;
    struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
    unsigned long flags;

    if (unpacked_lun >= TRANSPORT_MAX_LUNS_PER_TPG) {
        se_cmd->scsi_sense_reason = TCM_NON_EXISTENT_LUN;
        se_cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
        return -ENODEV;
    }

    spin_lock_irqsave(&se_sess->se_node_acl->device_list_lock, flags);
    se_cmd->se_deve = se_sess->se_node_acl->device_list[unpacked_lun];
    deve = se_cmd->se_deve;

    if (deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS) {
        se_tmr->tmr_lun = deve->se_lun;
        se_cmd->se_lun = deve->se_lun;
        se_lun = deve->se_lun;
        se_cmd->pr_res_key = deve->pr_res_key;
        se_cmd->orig_fe_lun = unpacked_lun;
    }
    spin_unlock_irqrestore(&se_sess->se_node_acl->device_list_lock, flags);

    if (!se_lun) {
        pr_debug("TARGET_CORE[%s]: Detected NON_EXISTENT_LUN"
            " Access for 0x%08x\n",
            se_cmd->se_tfo->get_fabric_name(),
            unpacked_lun);
        se_cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
        return -ENODEV;
    }
    /*
     * Determine if the struct se_lun is online.
     * FIXME: Check for LUN_RESET + UNIT Attention
     */
    if (se_dev_check_online(se_lun->lun_se_dev) != 0) {
        se_cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
        return -ENODEV;
    }

    /* Directly associate cmd with se_dev */
    se_cmd->se_dev = se_lun->lun_se_dev;
    se_tmr->tmr_dev = se_lun->lun_se_dev;

    spin_lock_irqsave(&se_tmr->tmr_dev->se_tmr_lock, flags);
    list_add_tail(&se_tmr->tmr_list, &se_tmr->tmr_dev->dev_tmr_list);
    spin_unlock_irqrestore(&se_tmr->tmr_dev->se_tmr_lock, flags);

    return 0;
}
EXPORT_SYMBOL(transport_lookup_tmr_lun);

/*
 * This function is called from core_scsi3_emulate_pro_register_and_move()
 * and core_scsi3_decode_spec_i_port(), and will increment &deve->pr_ref_count
 * when a matching rtpi is found.
 */
struct se_dev_entry *core_get_se_deve_from_rtpi(
    struct se_node_acl *nacl,
    u16 rtpi)
{
    struct se_dev_entry *deve;
    struct se_lun *lun;
    struct se_port *port;
    struct se_portal_group *tpg = nacl->se_tpg;
    u32 i;

    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;

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

        atomic_inc(&deve->pr_ref_count);
        smp_mb__after_atomic_inc();
        spin_unlock_irq(&nacl->device_list_lock);

        return deve;
    }
    spin_unlock_irq(&nacl->device_list_lock);

    return NULL;
}

int core_free_device_list_for_node(
    struct se_node_acl *nacl,
    struct se_portal_group *tpg)
{
    struct se_dev_entry *deve;
    struct se_lun *lun;
    u32 i;

    if (!nacl->device_list)
        return 0;

    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);

    array_free(nacl->device_list, TRANSPORT_MAX_LUNS_PER_TPG);
    nacl->device_list = NULL;

    return 0;
}

void core_dec_lacl_count(struct se_node_acl *se_nacl, struct se_cmd *se_cmd)
{
    struct se_dev_entry *deve;
    unsigned long flags;

    spin_lock_irqsave(&se_nacl->device_list_lock, flags);
    deve = se_nacl->device_list[se_cmd->orig_fe_lun];
    deve->deve_cmds--;
    spin_unlock_irqrestore(&se_nacl->device_list_lock, flags);
}

void core_update_device_list_access(
    u32 mapped_lun,
    u32 lun_access,
    struct se_node_acl *nacl)
{
    struct se_dev_entry *deve;

    spin_lock_irq(&nacl->device_list_lock);
    deve = nacl->device_list[mapped_lun];
    if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) {
        deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_ONLY;
        deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE;
    } else {
        deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_WRITE;
        deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_ONLY;
    }
    spin_unlock_irq(&nacl->device_list_lock);
}

/*      core_enable_device_list_for_node():
 *
 *
 */
int core_enable_device_list_for_node(
    struct se_lun *lun,
    struct se_lun_acl *lun_acl,
    u32 mapped_lun,
    u32 lun_access,
    struct se_node_acl *nacl,
    struct se_portal_group *tpg)
{
    struct se_port *port = lun->lun_sep;
    struct se_dev_entry *deve;

    spin_lock_irq(&nacl->device_list_lock);

    deve = nacl->device_list[mapped_lun];

    /*
     * Check if the call is handling demo mode -> explict LUN ACL
     * transition.  This transition must be for the same struct se_lun
     * + mapped_lun that was setup in demo mode..
     */
    if (deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS) {
        if (deve->se_lun_acl != NULL) {
            pr_err("struct se_dev_entry->se_lun_acl"
                   " already set for demo mode -> explict"
                   " LUN ACL transition\n");
            spin_unlock_irq(&nacl->device_list_lock);
            return -EINVAL;
        }
        if (deve->se_lun != lun) {
            pr_err("struct se_dev_entry->se_lun does"
                   " match passed struct se_lun for demo mode"
                   " -> explict LUN ACL transition\n");
            spin_unlock_irq(&nacl->device_list_lock);
            return -EINVAL;
        }
        deve->se_lun_acl = lun_acl;

        if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) {
            deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_ONLY;
            deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE;
        } else {
            deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_WRITE;
            deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_ONLY;
        }

        spin_unlock_irq(&nacl->device_list_lock);
        return 0;
    }

    deve->se_lun = lun;
    deve->se_lun_acl = lun_acl;
    deve->mapped_lun = mapped_lun;
    deve->lun_flags |= TRANSPORT_LUNFLAGS_INITIATOR_ACCESS;

    if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) {
        deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_ONLY;
        deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE;
    } else {
        deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_WRITE;
        deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_ONLY;
    }

    deve->creation_time = get_jiffies_64();
    deve->attach_count++;
    spin_unlock_irq(&nacl->device_list_lock);

    spin_lock_bh(&port->sep_alua_lock);
    list_add_tail(&deve->alua_port_list, &port->sep_alua_list);
    spin_unlock_bh(&port->sep_alua_lock);

    return 0;
}

/*      core_disable_device_list_for_node():
 *
 *
 */
int core_disable_device_list_for_node(
    struct se_lun *lun,
    struct se_lun_acl *lun_acl,
    u32 mapped_lun,
    u32 lun_access,
    struct se_node_acl *nacl,
    struct se_portal_group *tpg)
{
    struct se_port *port = lun->lun_sep;
    struct se_dev_entry *deve = nacl->device_list[mapped_lun];

    /*
     * If the MappedLUN entry is being disabled, the entry in
     * port->sep_alua_list must be removed now before clearing the
     * struct se_dev_entry pointers below as logic in
     * core_alua_do_transition_tg_pt() depends on these being present.
     *
     * deve->se_lun_acl will be NULL for demo-mode created LUNs
     * that have not been explicitly converted to MappedLUNs ->
     * struct se_lun_acl, but we remove deve->alua_port_list from
     * port->sep_alua_list. This also means that active UAs and
     * NodeACL context specific PR metadata for demo-mode
     * MappedLUN *deve will be released below..
     */
    spin_lock_bh(&port->sep_alua_lock);
    list_del(&deve->alua_port_list);
    spin_unlock_bh(&port->sep_alua_lock);
    /*
     * Wait for any in process SPEC_I_PT=1 or REGISTER_AND_MOVE
     * PR operation to complete.
     */
    while (atomic_read(&deve->pr_ref_count) != 0)
        cpu_relax();

    spin_lock_irq(&nacl->device_list_lock);
    /*
     * Disable struct se_dev_entry LUN ACL mapping
     */
    core_scsi3_ua_release_all(deve);
    deve->se_lun = NULL;
    deve->se_lun_acl = NULL;
    deve->lun_flags = 0;
    deve->creation_time = 0;
    deve->attach_count--;
    spin_unlock_irq(&nacl->device_list_lock);

    core_scsi3_free_pr_reg_from_nacl(lun->lun_se_dev, nacl);
    return 0;
}

/*      core_clear_lun_from_tpg():
 *
 *
 */
void core_clear_lun_from_tpg(struct se_lun *lun, struct se_portal_group *tpg)
{
    struct se_node_acl *nacl;
    struct se_dev_entry *deve;
    u32 i;

    spin_lock_irq(&tpg->acl_node_lock);
    list_for_each_entry(nacl, &tpg->acl_node_list, acl_list) {
        spin_unlock_irq(&tpg->acl_node_lock);

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

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

static struct se_port *core_alloc_port(struct se_device *dev)
{
    struct se_port *port, *port_tmp;

    port = kzalloc(sizeof(struct se_port), GFP_KERNEL);
    if (!port) {
        pr_err("Unable to allocate struct se_port\n");
        return ERR_PTR(-ENOMEM);
    }
    INIT_LIST_HEAD(&port->sep_alua_list);
    INIT_LIST_HEAD(&port->sep_list);
    atomic_set(&port->sep_tg_pt_secondary_offline, 0);
    spin_lock_init(&port->sep_alua_lock);
    mutex_init(&port->sep_tg_pt_md_mutex);

    spin_lock(&dev->se_port_lock);
    if (dev->dev_port_count == 0x0000ffff) {
        pr_warn("Reached dev->dev_port_count =="
                " 0x0000ffff\n");
        spin_unlock(&dev->se_port_lock);
        return ERR_PTR(-ENOSPC);
    }
again:
    /*
     * Allocate the next RELATIVE TARGET PORT IDENTIFIER for this struct se_device
     * Here is the table from spc4r17 section 7.7.3.8.
     *
     *    Table 473 -- RELATIVE TARGET PORT IDENTIFIER field
     *
     * Code      Description
     * 0h        Reserved
     * 1h        Relative port 1, historically known as port A
     * 2h        Relative port 2, historically known as port B
     * 3h to FFFFh    Relative port 3 through 65 535
     */
    port->sep_rtpi = dev->dev_rpti_counter++;
    if (!port->sep_rtpi)
        goto again;

    list_for_each_entry(port_tmp, &dev->dev_sep_list, sep_list) {
        /*
         * Make sure RELATIVE TARGET PORT IDENTIFIER is unique
         * for 16-bit wrap..
         */
        if (port->sep_rtpi == port_tmp->sep_rtpi)
            goto again;
    }
    spin_unlock(&dev->se_port_lock);

    return port;
}

static void core_export_port(
    struct se_device *dev,
    struct se_portal_group *tpg,
    struct se_port *port,
    struct se_lun *lun)
{
    struct se_subsystem_dev *su_dev = dev->se_sub_dev;
    struct t10_alua_tg_pt_gp_member *tg_pt_gp_mem = NULL;

    spin_lock(&dev->se_port_lock);
    spin_lock(&lun->lun_sep_lock);
    port->sep_tpg = tpg;
    port->sep_lun = lun;
    lun->lun_sep = port;
    spin_unlock(&lun->lun_sep_lock);

    list_add_tail(&port->sep_list, &dev->dev_sep_list);
    spin_unlock(&dev->se_port_lock);

    if (su_dev->t10_alua.alua_type == SPC3_ALUA_EMULATED) {
        tg_pt_gp_mem = core_alua_allocate_tg_pt_gp_mem(port);
        if (IS_ERR(tg_pt_gp_mem) || !tg_pt_gp_mem) {
            pr_err("Unable to allocate t10_alua_tg_pt"
                    "_gp_member_t\n");
            return;
        }
        spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
        __core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
            su_dev->t10_alua.default_tg_pt_gp);
        spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
        pr_debug("%s/%s: Adding to default ALUA Target Port"
            " Group: alua/default_tg_pt_gp\n",
            dev->transport->name, tpg->se_tpg_tfo->get_fabric_name());
    }

    dev->dev_port_count++;
    port->sep_index = port->sep_rtpi; /* RELATIVE TARGET PORT IDENTIFIER */
}

/*
 *  Called with struct se_device->se_port_lock spinlock held.
 */
static void core_release_port(struct se_device *dev, struct se_port *port)
    __releases(&dev->se_port_lock) __acquires(&dev->se_port_lock)
{
    /*
     * Wait for any port reference for PR ALL_TG_PT=1 operation
     * to complete in __core_scsi3_alloc_registration()
     */
    spin_unlock(&dev->se_port_lock);
    if (atomic_read(&port->sep_tg_pt_ref_cnt))
        cpu_relax();
    spin_lock(&dev->se_port_lock);

    core_alua_free_tg_pt_gp_mem(port);

    list_del(&port->sep_list);
    dev->dev_port_count--;
    kfree(port);
}

int core_dev_export(
    struct se_device *dev,
    struct se_portal_group *tpg,
    struct se_lun *lun)
{
    struct se_port *port;

    port = core_alloc_port(dev);
    if (IS_ERR(port))
        return PTR_ERR(port);

    lun->lun_se_dev = dev;
    se_dev_start(dev);

    atomic_inc(&dev->dev_export_obj.obj_access_count);
    core_export_port(dev, tpg, port, lun);
    return 0;
}

void core_dev_unexport(
    struct se_device *dev,
    struct se_portal_group *tpg,
    struct se_lun *lun)
{
    struct se_port *port = lun->lun_sep;

    spin_lock(&lun->lun_sep_lock);
    if (lun->lun_se_dev == NULL) {
        spin_unlock(&lun->lun_sep_lock);
        return;
    }
    spin_unlock(&lun->lun_sep_lock);

    spin_lock(&dev->se_port_lock);
    atomic_dec(&dev->dev_export_obj.obj_access_count);
    core_release_port(dev, port);
    spin_unlock(&dev->se_port_lock);

    se_dev_stop(dev);
    lun->lun_se_dev = NULL;
}

int target_report_luns(struct se_cmd *se_cmd)
{
    struct se_dev_entry *deve;
    struct se_session *se_sess = se_cmd->se_sess;
    unsigned char *buf;
    u32 lun_count = 0, offset = 8, i;

    if (se_cmd->data_length < 16) {
        pr_warn("REPORT LUNS allocation length %u too small\n",
            se_cmd->data_length);
        se_cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
        return -EINVAL;
    }

    buf = transport_kmap_data_sg(se_cmd);
    if (!buf)
        return -ENOMEM;

    /*
     * If no struct se_session pointer is present, this struct se_cmd is
     * coming via a target_core_mod PASSTHROUGH op, and not through
     * a $FABRIC_MOD.  In that case, report LUN=0 only.
     */
    if (!se_sess) {
        int_to_scsilun(0, (struct scsi_lun *)&buf[offset]);
        lun_count = 1;
        goto done;
    }

    spin_lock_irq(&se_sess->se_node_acl->device_list_lock);
    for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
        deve = se_sess->se_node_acl->device_list[i];
        if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS))
            continue;
        /*
         * We determine the correct LUN LIST LENGTH even once we
         * have reached the initial allocation length.
         * See SPC2-R20 7.19.
         */
        lun_count++;
        if ((offset + 8) > se_cmd->data_length)
            continue;

        int_to_scsilun(deve->mapped_lun, (struct scsi_lun *)&buf[offset]);
        offset += 8;
    }
    spin_unlock_irq(&se_sess->se_node_acl->device_list_lock);

    /*
     * See SPC3 r07, page 159.
     */
done:
    lun_count *= 8;
    buf[0] = ((lun_count >> 24) & 0xff);
    buf[1] = ((lun_count >> 16) & 0xff);
    buf[2] = ((lun_count >> 8) & 0xff);
    buf[3] = (lun_count & 0xff);
    transport_kunmap_data_sg(se_cmd);

    target_complete_cmd(se_cmd, GOOD);
    return 0;
}

/*  se_release_device_for_hba():
 *
 *
 */
void se_release_device_for_hba(struct se_device *dev)
{
    struct se_hba *hba = dev->se_hba;

    if ((dev->dev_status & TRANSPORT_DEVICE_ACTIVATED) ||
        (dev->dev_status & TRANSPORT_DEVICE_DEACTIVATED) ||
        (dev->dev_status & TRANSPORT_DEVICE_SHUTDOWN) ||
        (dev->dev_status & TRANSPORT_DEVICE_OFFLINE_ACTIVATED) ||
        (dev->dev_status & TRANSPORT_DEVICE_OFFLINE_DEACTIVATED))
        se_dev_stop(dev);

    if (dev->dev_ptr) {
        destroy_workqueue(dev->tmr_wq);
        if (dev->transport->free_device)
            dev->transport->free_device(dev->dev_ptr);
    }

    spin_lock(&hba->device_lock);
    list_del(&dev->dev_list);
    hba->dev_count--;
    spin_unlock(&hba->device_lock);

    core_scsi3_free_all_registrations(dev);
    se_release_vpd_for_dev(dev);

    kfree(dev);
}

void se_release_vpd_for_dev(struct se_device *dev)
{
    struct t10_vpd *vpd, *vpd_tmp;

    spin_lock(&dev->se_sub_dev->t10_wwn.t10_vpd_lock);
    list_for_each_entry_safe(vpd, vpd_tmp,
            &dev->se_sub_dev->t10_wwn.t10_vpd_list, vpd_list) {
        list_del(&vpd->vpd_list);
        kfree(vpd);
    }
    spin_unlock(&dev->se_sub_dev->t10_wwn.t10_vpd_lock);
}

/*  se_free_virtual_device():
 *
 *  Used for IBLOCK, RAMDISK, and FILEIO Transport Drivers.
 */
int se_free_virtual_device(struct se_device *dev, struct se_hba *hba)
{
    if (!list_empty(&dev->dev_sep_list))
        dump_stack();

    core_alua_free_lu_gp_mem(dev);
    se_release_device_for_hba(dev);

    return 0;
}

static void se_dev_start(struct se_device *dev)
{
    struct se_hba *hba = dev->se_hba;

    spin_lock(&hba->device_lock);
    atomic_inc(&dev->dev_obj.obj_access_count);
    if (atomic_read(&dev->dev_obj.obj_access_count) == 1) {
        if (dev->dev_status & TRANSPORT_DEVICE_DEACTIVATED) {
            dev->dev_status &= ~TRANSPORT_DEVICE_DEACTIVATED;
            dev->dev_status |= TRANSPORT_DEVICE_ACTIVATED;
        } else if (dev->dev_status &
               TRANSPORT_DEVICE_OFFLINE_DEACTIVATED) {
            dev->dev_status &=
                ~TRANSPORT_DEVICE_OFFLINE_DEACTIVATED;
            dev->dev_status |= TRANSPORT_DEVICE_OFFLINE_ACTIVATED;
        }
    }
    spin_unlock(&hba->device_lock);
}

static void se_dev_stop(struct se_device *dev)
{
    struct se_hba *hba = dev->se_hba;

    spin_lock(&hba->device_lock);
    atomic_dec(&dev->dev_obj.obj_access_count);
    if (atomic_read(&dev->dev_obj.obj_access_count) == 0) {
        if (dev->dev_status & TRANSPORT_DEVICE_ACTIVATED) {
            dev->dev_status &= ~TRANSPORT_DEVICE_ACTIVATED;
            dev->dev_status |= TRANSPORT_DEVICE_DEACTIVATED;
        } else if (dev->dev_status &
               TRANSPORT_DEVICE_OFFLINE_ACTIVATED) {
            dev->dev_status &= ~TRANSPORT_DEVICE_OFFLINE_ACTIVATED;
            dev->dev_status |= TRANSPORT_DEVICE_OFFLINE_DEACTIVATED;
        }
    }
    spin_unlock(&hba->device_lock);
}

int se_dev_check_online(struct se_device *dev)
{
    unsigned long flags;
    int ret;

    spin_lock_irqsave(&dev->dev_status_lock, flags);
    ret = ((dev->dev_status & TRANSPORT_DEVICE_ACTIVATED) ||
           (dev->dev_status & TRANSPORT_DEVICE_DEACTIVATED)) ? 0 : 1;
    spin_unlock_irqrestore(&dev->dev_status_lock, flags);

    return ret;
}

int se_dev_check_shutdown(struct se_device *dev)
{
    int ret;

    spin_lock_irq(&dev->dev_status_lock);
    ret = (dev->dev_status & TRANSPORT_DEVICE_SHUTDOWN);
    spin_unlock_irq(&dev->dev_status_lock);

    return ret;
}

static u32 se_dev_align_max_sectors(u32 max_sectors, u32 block_size)
{
    u32 aligned_max_sectors;
    u32 alignment;
    /*
     * Limit max_sectors to a PAGE_SIZE aligned value for modern
     * transport_allocate_data_tasks() operation.
     */
    alignment = max(1ul, PAGE_SIZE / block_size);
    aligned_max_sectors = rounddown(max_sectors, alignment);

    if (max_sectors != aligned_max_sectors)
        pr_info("Rounding down aligned max_sectors from %u to %u\n",
            max_sectors, aligned_max_sectors);

    return aligned_max_sectors;
}

void se_dev_set_default_attribs(
    struct se_device *dev,
    struct se_dev_limits *dev_limits)
{
    struct queue_limits *limits = &dev_limits->limits;

    dev->se_sub_dev->se_dev_attrib.emulate_dpo = DA_EMULATE_DPO;
    dev->se_sub_dev->se_dev_attrib.emulate_fua_write = DA_EMULATE_FUA_WRITE;
    dev->se_sub_dev->se_dev_attrib.emulate_fua_read = DA_EMULATE_FUA_READ;
    dev->se_sub_dev->se_dev_attrib.emulate_write_cache = DA_EMULATE_WRITE_CACHE;
    dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl = DA_EMULATE_UA_INTLLCK_CTRL;
    dev->se_sub_dev->se_dev_attrib.emulate_tas = DA_EMULATE_TAS;
    dev->se_sub_dev->se_dev_attrib.emulate_tpu = DA_EMULATE_TPU;
    dev->se_sub_dev->se_dev_attrib.emulate_tpws = DA_EMULATE_TPWS;
    dev->se_sub_dev->se_dev_attrib.emulate_reservations = DA_EMULATE_RESERVATIONS;
    dev->se_sub_dev->se_dev_attrib.emulate_alua = DA_EMULATE_ALUA;
    dev->se_sub_dev->se_dev_attrib.enforce_pr_isids = DA_ENFORCE_PR_ISIDS;
    dev->se_sub_dev->se_dev_attrib.is_nonrot = DA_IS_NONROT;
    dev->se_sub_dev->se_dev_attrib.emulate_rest_reord = DA_EMULATE_REST_REORD;
    /*
     * The TPU=1 and TPWS=1 settings will be set in TCM/IBLOCK
     * iblock_create_virtdevice() from struct queue_limits values
     * if blk_queue_discard()==1
     */
    dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count = DA_MAX_UNMAP_LBA_COUNT;
    dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count =
        DA_MAX_UNMAP_BLOCK_DESC_COUNT;
    dev->se_sub_dev->se_dev_attrib.unmap_granularity = DA_UNMAP_GRANULARITY_DEFAULT;
    dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
                DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT;
    /*
     * block_size is based on subsystem plugin dependent requirements.
     */
    dev->se_sub_dev->se_dev_attrib.hw_block_size = limits->logical_block_size;
    dev->se_sub_dev->se_dev_attrib.block_size = limits->logical_block_size;
    /*
     * Align max_hw_sectors down to PAGE_SIZE I/O transfers
     */
    limits->max_hw_sectors = se_dev_align_max_sectors(limits->max_hw_sectors,
                        limits->logical_block_size);
    dev->se_sub_dev->se_dev_attrib.hw_max_sectors = limits->max_hw_sectors;

    /*
     * Set fabric_max_sectors, which is reported in block limits
     * VPD page (B0h).
     */
    dev->se_sub_dev->se_dev_attrib.fabric_max_sectors = DA_FABRIC_MAX_SECTORS;
    /*
     * Set optimal_sectors from fabric_max_sectors, which can be
     * lowered via configfs.
     */
    dev->se_sub_dev->se_dev_attrib.optimal_sectors = DA_FABRIC_MAX_SECTORS;
    /*
     * queue_depth is based on subsystem plugin dependent requirements.
     */
    dev->se_sub_dev->se_dev_attrib.hw_queue_depth = dev_limits->hw_queue_depth;
    dev->se_sub_dev->se_dev_attrib.queue_depth = dev_limits->queue_depth;
}

int se_dev_set_max_unmap_lba_count(
    struct se_device *dev,
    u32 max_unmap_lba_count)
{
    dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count = max_unmap_lba_count;
    pr_debug("dev[%p]: Set max_unmap_lba_count: %u\n",
            dev, dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count);
    return 0;
}

int se_dev_set_max_unmap_block_desc_count(
    struct se_device *dev,
    u32 max_unmap_block_desc_count)
{
    dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count =
        max_unmap_block_desc_count;
    pr_debug("dev[%p]: Set max_unmap_block_desc_count: %u\n",
            dev, dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count);
    return 0;
}

int se_dev_set_unmap_granularity(
    struct se_device *dev,
    u32 unmap_granularity)
{
    dev->se_sub_dev->se_dev_attrib.unmap_granularity = unmap_granularity;
    pr_debug("dev[%p]: Set unmap_granularity: %u\n",
            dev, dev->se_sub_dev->se_dev_attrib.unmap_granularity);
    return 0;
}

int se_dev_set_unmap_granularity_alignment(
    struct se_device *dev,
    u32 unmap_granularity_alignment)
{
    dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment = unmap_granularity_alignment;
    pr_debug("dev[%p]: Set unmap_granularity_alignment: %u\n",
            dev, dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment);
    return 0;
}

int se_dev_set_emulate_dpo(struct se_device *dev, int flag)
{
    if (flag != 0 && flag != 1) {
        pr_err("Illegal value %d\n", flag);
        return -EINVAL;
    }

    if (flag) {
        pr_err("dpo_emulated not supported\n");
        return -EINVAL;
    }

    return 0;
}

int se_dev_set_emulate_fua_write(struct se_device *dev, int flag)
{
    if (flag != 0 && flag != 1) {
        pr_err("Illegal value %d\n", flag);
        return -EINVAL;
    }

    if (flag &&
        dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
        pr_err("emulate_fua_write not supported for pSCSI\n");
        return -EINVAL;
    }
    dev->se_sub_dev->se_dev_attrib.emulate_fua_write = flag;
    pr_debug("dev[%p]: SE Device Forced Unit Access WRITEs: %d\n",
            dev, dev->se_sub_dev->se_dev_attrib.emulate_fua_write);
    return 0;
}

int se_dev_set_emulate_fua_read(struct se_device *dev, int flag)
{
    if (flag != 0 && flag != 1) {
        pr_err("Illegal value %d\n", flag);
        return -EINVAL;
    }

    if (flag) {
        pr_err("ua read emulated not supported\n");
        return -EINVAL;
    }

    return 0;
}

int se_dev_set_emulate_write_cache(struct se_device *dev, int flag)
{
    if (flag != 0 && flag != 1) {
        pr_err("Illegal value %d\n", flag);
        return -EINVAL;
    }
    if (flag &&
        dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
        pr_err("emulate_write_cache not supported for pSCSI\n");
        return -EINVAL;
    }
    dev->se_sub_dev->se_dev_attrib.emulate_write_cache = flag;
    pr_debug("dev[%p]: SE Device WRITE_CACHE_EMULATION flag: %d\n",
            dev, dev->se_sub_dev->se_dev_attrib.emulate_write_cache);
    return 0;
}

int se_dev_set_emulate_ua_intlck_ctrl(struct se_device *dev, int flag)
{
    if ((flag != 0) && (flag != 1) && (flag != 2)) {
        pr_err("Illegal value %d\n", flag);
        return -EINVAL;
    }

    if (atomic_read(&dev->dev_export_obj.obj_access_count)) {
        pr_err("dev[%p]: Unable to change SE Device"
            " UA_INTRLCK_CTRL while dev_export_obj: %d count"
            " exists\n", dev,
            atomic_read(&dev->dev_export_obj.obj_access_count));
        return -EINVAL;
    }
    dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl = flag;
    pr_debug("dev[%p]: SE Device UA_INTRLCK_CTRL flag: %d\n",
        dev, dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl);

    return 0;
}

int se_dev_set_emulate_tas(struct se_device *dev, int flag)
{
    if ((flag != 0) && (flag != 1)) {
        pr_err("Illegal value %d\n", flag);
        return -EINVAL;
    }

    if (atomic_read(&dev->dev_export_obj.obj_access_count)) {
        pr_err("dev[%p]: Unable to change SE Device TAS while"
            " dev_export_obj: %d count exists\n", dev,
            atomic_read(&dev->dev_export_obj.obj_access_count));
        return -EINVAL;
    }
    dev->se_sub_dev->se_dev_attrib.emulate_tas = flag;
    pr_debug("dev[%p]: SE Device TASK_ABORTED status bit: %s\n",
        dev, (dev->se_sub_dev->se_dev_attrib.emulate_tas) ? "Enabled" : "Disabled");

    return 0;
}

int se_dev_set_emulate_tpu(struct se_device *dev, int flag)
{
    if ((flag != 0) && (flag != 1)) {
        pr_err("Illegal value %d\n", flag);
        return -EINVAL;
    }
    /*
     * We expect this value to be non-zero when generic Block Layer
     * Discard supported is detected iblock_create_virtdevice().
     */
    if (flag && !dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count) {
        pr_err("Generic Block Discard not supported\n");
        return -ENOSYS;
    }

    dev->se_sub_dev->se_dev_attrib.emulate_tpu = flag;
    pr_debug("dev[%p]: SE Device Thin Provisioning UNMAP bit: %d\n",
                dev, flag);
    return 0;
}

int se_dev_set_emulate_tpws(struct se_device *dev, int flag)
{
    if ((flag != 0) && (flag != 1)) {
        pr_err("Illegal value %d\n", flag);
        return -EINVAL;
    }
    /*
     * We expect this value to be non-zero when generic Block Layer
     * Discard supported is detected iblock_create_virtdevice().
     */
    if (flag && !dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count) {
        pr_err("Generic Block Discard not supported\n");
        return -ENOSYS;
    }

    dev->se_sub_dev->se_dev_attrib.emulate_tpws = flag;
    pr_debug("dev[%p]: SE Device Thin Provisioning WRITE_SAME: %d\n",
                dev, flag);
    return 0;
}

int se_dev_set_enforce_pr_isids(struct se_device *dev, int flag)
{
    if ((flag != 0) && (flag != 1)) {
        pr_err("Illegal value %d\n", flag);
        return -EINVAL;
    }
    dev->se_sub_dev->se_dev_attrib.enforce_pr_isids = flag;
    pr_debug("dev[%p]: SE Device enforce_pr_isids bit: %s\n", dev,
        (dev->se_sub_dev->se_dev_attrib.enforce_pr_isids) ? "Enabled" : "Disabled");
    return 0;
}

int se_dev_set_is_nonrot(struct se_device *dev, int flag)
{
    if ((flag != 0) && (flag != 1)) {
        printk(KERN_ERR "Illegal value %d\n", flag);
        return -EINVAL;
    }
    dev->se_sub_dev->se_dev_attrib.is_nonrot = flag;
    pr_debug("dev[%p]: SE Device is_nonrot bit: %d\n",
           dev, flag);
    return 0;
}

int se_dev_set_emulate_rest_reord(struct se_device *dev, int flag)
{
    if (flag != 0) {
        printk(KERN_ERR "dev[%p]: SE Device emulatation of restricted"
            " reordering not implemented\n", dev);
        return -ENOSYS;
    }
    dev->se_sub_dev->se_dev_attrib.emulate_rest_reord = flag;
    pr_debug("dev[%p]: SE Device emulate_rest_reord: %d\n", dev, flag);
    return 0;
}

/*
 * Note, this can only be called on unexported SE Device Object.
 */
int se_dev_set_queue_depth(struct se_device *dev, u32 queue_depth)
{
    if (atomic_read(&dev->dev_export_obj.obj_access_count)) {
        pr_err("dev[%p]: Unable to change SE Device TCQ while"
            " dev_export_obj: %d count exists\n", dev,
            atomic_read(&dev->dev_export_obj.obj_access_count));
        return -EINVAL;
    }
    if (!queue_depth) {
        pr_err("dev[%p]: Illegal ZERO value for queue"
            "_depth\n", dev);
        return -EINVAL;
    }

    if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
        if (queue_depth > dev->se_sub_dev->se_dev_attrib.hw_queue_depth) {
            pr_err("dev[%p]: Passed queue_depth: %u"
                " exceeds TCM/SE_Device TCQ: %u\n",
                dev, queue_depth,
                dev->se_sub_dev->se_dev_attrib.hw_queue_depth);
            return -EINVAL;
        }
    } else {
        if (queue_depth > dev->se_sub_dev->se_dev_attrib.queue_depth) {
            if (queue_depth > dev->se_sub_dev->se_dev_attrib.hw_queue_depth) {
                pr_err("dev[%p]: Passed queue_depth:"
                    " %u exceeds TCM/SE_Device MAX"
                    " TCQ: %u\n", dev, queue_depth,
                    dev->se_sub_dev->se_dev_attrib.hw_queue_depth);
                return -EINVAL;
            }
        }
    }

    dev->se_sub_dev->se_dev_attrib.queue_depth = dev->queue_depth = queue_depth;
    pr_debug("dev[%p]: SE Device TCQ Depth changed to: %u\n",
            dev, queue_depth);
    return 0;
}

int se_dev_set_fabric_max_sectors(struct se_device *dev, u32 fabric_max_sectors)
{
    if (atomic_read(&dev->dev_export_obj.obj_access_count)) {
        pr_err("dev[%p]: Unable to change SE Device"
            " fabric_max_sectors while dev_export_obj: %d count exists\n",
            dev, atomic_read(&dev->dev_export_obj.obj_access_count));
        return -EINVAL;
    }
    if (!fabric_max_sectors) {
        pr_err("dev[%p]: Illegal ZERO value for"
            " fabric_max_sectors\n", dev);
        return -EINVAL;
    }
    if (fabric_max_sectors < DA_STATUS_MAX_SECTORS_MIN) {
        pr_err("dev[%p]: Passed fabric_max_sectors: %u less than"
            " DA_STATUS_MAX_SECTORS_MIN: %u\n", dev, fabric_max_sectors,
                DA_STATUS_MAX_SECTORS_MIN);
        return -EINVAL;
    }
    if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
        if (fabric_max_sectors > dev->se_sub_dev->se_dev_attrib.hw_max_sectors) {
            pr_err("dev[%p]: Passed fabric_max_sectors: %u"
                " greater than TCM/SE_Device max_sectors:"
                " %u\n", dev, fabric_max_sectors,
                dev->se_sub_dev->se_dev_attrib.hw_max_sectors);
             return -EINVAL;
        }
    } else {
        if (fabric_max_sectors > DA_STATUS_MAX_SECTORS_MAX) {
            pr_err("dev[%p]: Passed fabric_max_sectors: %u"
                " greater than DA_STATUS_MAX_SECTORS_MAX:"
                " %u\n", dev, fabric_max_sectors,
                DA_STATUS_MAX_SECTORS_MAX);
            return -EINVAL;
        }
    }
    /*
     * Align max_sectors down to PAGE_SIZE to follow transport_allocate_data_tasks()
     */
    fabric_max_sectors = se_dev_align_max_sectors(fabric_max_sectors,
                              dev->se_sub_dev->se_dev_attrib.block_size);

    dev->se_sub_dev->se_dev_attrib.fabric_max_sectors = fabric_max_sectors;
    pr_debug("dev[%p]: SE Device max_sectors changed to %u\n",
            dev, fabric_max_sectors);
    return 0;
}

int se_dev_set_optimal_sectors(struct se_device *dev, u32 optimal_sectors)
{
    if (atomic_read(&dev->dev_export_obj.obj_access_count)) {
        pr_err("dev[%p]: Unable to change SE Device"
            " optimal_sectors while dev_export_obj: %d count exists\n",
            dev, atomic_read(&dev->dev_export_obj.obj_access_count));
        return -EINVAL;
    }
    if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
        pr_err("dev[%p]: Passed optimal_sectors cannot be"
                " changed for TCM/pSCSI\n", dev);
        return -EINVAL;
    }
    if (optimal_sectors > dev->se_sub_dev->se_dev_attrib.fabric_max_sectors) {
        pr_err("dev[%p]: Passed optimal_sectors %u cannot be"
            " greater than fabric_max_sectors: %u\n", dev,
            optimal_sectors, dev->se_sub_dev->se_dev_attrib.fabric_max_sectors);
        return -EINVAL;
    }

    dev->se_sub_dev->se_dev_attrib.optimal_sectors = optimal_sectors;
    pr_debug("dev[%p]: SE Device optimal_sectors changed to %u\n",
            dev, optimal_sectors);
    return 0;
}

int se_dev_set_block_size(struct se_device *dev, u32 block_size)
{
    if (atomic_read(&dev->dev_export_obj.obj_access_count)) {
        pr_err("dev[%p]: Unable to change SE Device block_size"
            " while dev_export_obj: %d count exists\n", dev,
            atomic_read(&dev->dev_export_obj.obj_access_count));
        return -EINVAL;
    }

    if ((block_size != 512) &&
        (block_size != 1024) &&
        (block_size != 2048) &&
        (block_size != 4096)) {
        pr_err("dev[%p]: Illegal value for block_device: %u"
            " for SE device, must be 512, 1024, 2048 or 4096\n",
            dev, block_size);
        return -EINVAL;
    }

    if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
        pr_err("dev[%p]: Not allowed to change block_size for"
            " Physical Device, use for Linux/SCSI to change"
            " block_size for underlying hardware\n", dev);
        return -EINVAL;
    }

    dev->se_sub_dev->se_dev_attrib.block_size = block_size;
    pr_debug("dev[%p]: SE Device block_size changed to %u\n",
            dev, block_size);
    return 0;
}

struct se_lun *core_dev_add_lun(
    struct se_portal_group *tpg,
    struct se_device *dev,
    u32 lun)
{
    struct se_lun *lun_p;
    int rc;

    if (atomic_read(&dev->dev_access_obj.obj_access_count) != 0) {
        pr_err("Unable to export struct se_device while dev_access_obj: %d\n",
            atomic_read(&dev->dev_access_obj.obj_access_count));
        return ERR_PTR(-EACCES);
    }

    lun_p = core_tpg_pre_addlun(tpg, lun);
    if (IS_ERR(lun_p))
        return lun_p;

    rc = core_tpg_post_addlun(tpg, lun_p,
                TRANSPORT_LUNFLAGS_READ_WRITE, dev);
    if (rc < 0)
        return ERR_PTR(rc);

    pr_debug("%s_TPG[%u]_LUN[%u] - Activated %s Logical Unit from"
        " CORE HBA: %u\n", tpg->se_tpg_tfo->get_fabric_name(),
        tpg->se_tpg_tfo->tpg_get_tag(tpg), lun_p->unpacked_lun,
        tpg->se_tpg_tfo->get_fabric_name(), dev->se_hba->hba_id);
    /*
     * Update LUN maps for dynamically added initiators when
     * generate_node_acl is enabled.
     */
    if (tpg->se_tpg_tfo->tpg_check_demo_mode(tpg)) {
        struct se_node_acl *acl;
        spin_lock_irq(&tpg->acl_node_lock);
        list_for_each_entry(acl, &tpg->acl_node_list, acl_list) {
            if (acl->dynamic_node_acl &&
                (!tpg->se_tpg_tfo->tpg_check_demo_mode_login_only ||
                 !tpg->se_tpg_tfo->tpg_check_demo_mode_login_only(tpg))) {
                spin_unlock_irq(&tpg->acl_node_lock);
                core_tpg_add_node_to_devs(acl, tpg);
                spin_lock_irq(&tpg->acl_node_lock);
            }
        }
        spin_unlock_irq(&tpg->acl_node_lock);
    }

    return lun_p;
}

/*      core_dev_del_lun():
 *
 *
 */
int core_dev_del_lun(
    struct se_portal_group *tpg,
    u32 unpacked_lun)
{
    struct se_lun *lun;

    lun = core_tpg_pre_dellun(tpg, unpacked_lun);
    if (IS_ERR(lun))
        return PTR_ERR(lun);

    core_tpg_post_dellun(tpg, lun);

    pr_debug("%s_TPG[%u]_LUN[%u] - Deactivated %s Logical Unit from"
        " device object\n", tpg->se_tpg_tfo->get_fabric_name(),
        tpg->se_tpg_tfo->tpg_get_tag(tpg), unpacked_lun,
        tpg->se_tpg_tfo->get_fabric_name());

    return 0;
}

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

    spin_lock(&tpg->tpg_lun_lock);
    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: %hu\n",
            tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
            TRANSPORT_MAX_LUNS_PER_TPG-1,
            tpg->se_tpg_tfo->tpg_get_tag(tpg));
        spin_unlock(&tpg->tpg_lun_lock);
        return NULL;
    }
    lun = tpg->tpg_lun_list[unpacked_lun];

    if (lun->lun_status != TRANSPORT_LUN_STATUS_FREE) {
        pr_err("%s Logical Unit Number: %u is not free on"
            " Target Portal Group: %hu, 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 NULL;
    }
    spin_unlock(&tpg->tpg_lun_lock);

    return lun;
}

/*      core_dev_get_lun():
 *
 *
 */
static struct se_lun *core_dev_get_lun(struct se_portal_group *tpg, u32 unpacked_lun)
{
    struct se_lun *lun;

    spin_lock(&tpg->tpg_lun_lock);
    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: %hu\n",
            tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
            TRANSPORT_MAX_LUNS_PER_TPG-1,
            tpg->se_tpg_tfo->tpg_get_tag(tpg));
        spin_unlock(&tpg->tpg_lun_lock);
        return NULL;
    }
    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: %hu, 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 NULL;
    }
    spin_unlock(&tpg->tpg_lun_lock);

    return lun;
}

struct se_lun_acl *core_dev_init_initiator_node_lun_acl(
    struct se_portal_group *tpg,
    u32 mapped_lun,
    char *initiatorname,
    int *ret)
{
    struct se_lun_acl *lacl;
    struct se_node_acl *nacl;

    if (strlen(initiatorname) >= TRANSPORT_IQN_LEN) {
        pr_err("%s InitiatorName exceeds maximum size.\n",
            tpg->se_tpg_tfo->get_fabric_name());
        *ret = -EOVERFLOW;
        return NULL;
    }
    nacl = core_tpg_get_initiator_node_acl(tpg, initiatorname);
    if (!nacl) {
        *ret = -EINVAL;
        return NULL;
    }
    lacl = kzalloc(sizeof(struct se_lun_acl), GFP_KERNEL);
    if (!lacl) {
        pr_err("Unable to allocate memory for struct se_lun_acl.\n");
        *ret = -ENOMEM;
        return NULL;
    }

    INIT_LIST_HEAD(&lacl->lacl_list);
    lacl->mapped_lun = mapped_lun;
    lacl->se_lun_nacl = nacl;
    snprintf(lacl->initiatorname, TRANSPORT_IQN_LEN, "%s", initiatorname);

    return lacl;
}

int core_dev_add_initiator_node_lun_acl(
    struct se_portal_group *tpg,
    struct se_lun_acl *lacl,
    u32 unpacked_lun,
    u32 lun_access)
{
    struct se_lun *lun;
    struct se_node_acl *nacl;

    lun = core_dev_get_lun(tpg, unpacked_lun);
    if (!lun) {
        pr_err("%s Logical Unit Number: %u is not active on"
            " Target Portal Group: %hu, ignoring request.\n",
            tpg->se_tpg_tfo->get_fabric_name(), unpacked_lun,
            tpg->se_tpg_tfo->tpg_get_tag(tpg));
        return -EINVAL;
    }

    nacl = lacl->se_lun_nacl;
    if (!nacl)
        return -EINVAL;

    if ((lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) &&
        (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE))
        lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;

    lacl->se_lun = lun;

    if (core_enable_device_list_for_node(lun, lacl, lacl->mapped_lun,
            lun_access, nacl, tpg) < 0)
        return -EINVAL;

    spin_lock(&lun->lun_acl_lock);
    list_add_tail(&lacl->lacl_list, &lun->lun_acl_list);
    atomic_inc(&lun->lun_acl_count);
    smp_mb__after_atomic_inc();
    spin_unlock(&lun->lun_acl_lock);

    pr_debug("%s_TPG[%hu]_LUN[%u->%u] - Added %s ACL for "
        " InitiatorNode: %s\n", tpg->se_tpg_tfo->get_fabric_name(),
        tpg->se_tpg_tfo->tpg_get_tag(tpg), unpacked_lun, lacl->mapped_lun,
        (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) ? "RW" : "RO",
        lacl->initiatorname);
    /*
     * Check to see if there are any existing persistent reservation APTPL
     * pre-registrations that need to be enabled for this LUN ACL..
     */
    core_scsi3_check_aptpl_registration(lun->lun_se_dev, tpg, lun, lacl);
    return 0;
}

/*      core_dev_del_initiator_node_lun_acl():
 *
 *
 */
int core_dev_del_initiator_node_lun_acl(
    struct se_portal_group *tpg,
    struct se_lun *lun,
    struct se_lun_acl *lacl)
{
    struct se_node_acl *nacl;

    nacl = lacl->se_lun_nacl;
    if (!nacl)
        return -EINVAL;

    spin_lock(&lun->lun_acl_lock);
    list_del(&lacl->lacl_list);
    atomic_dec(&lun->lun_acl_count);
    smp_mb__after_atomic_dec();
    spin_unlock(&lun->lun_acl_lock);

    core_disable_device_list_for_node(lun, NULL, lacl->mapped_lun,
        TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg);

    lacl->se_lun = NULL;

    pr_debug("%s_TPG[%hu]_LUN[%u] - Removed ACL for"
        " InitiatorNode: %s Mapped LUN: %u\n",
        tpg->se_tpg_tfo->get_fabric_name(),
        tpg->se_tpg_tfo->tpg_get_tag(tpg), lun->unpacked_lun,
        lacl->initiatorname, lacl->mapped_lun);

    return 0;
}

void core_dev_free_initiator_node_lun_acl(
    struct se_portal_group *tpg,
    struct se_lun_acl *lacl)
{
    pr_debug("%s_TPG[%hu] - Freeing ACL for %s InitiatorNode: %s"
        " Mapped LUN: %u\n", tpg->se_tpg_tfo->get_fabric_name(),
        tpg->se_tpg_tfo->tpg_get_tag(tpg),
        tpg->se_tpg_tfo->get_fabric_name(),
        lacl->initiatorname, lacl->mapped_lun);

    kfree(lacl);
}

int core_dev_setup_virtual_lun0(void)
{
    struct se_hba *hba;
    struct se_device *dev;
    struct se_subsystem_dev *se_dev = NULL;
    struct se_subsystem_api *t;
    char buf[16];
    int ret;

    hba = core_alloc_hba("rd_mcp", 0, HBA_FLAGS_INTERNAL_USE);
    if (IS_ERR(hba))
        return PTR_ERR(hba);

    lun0_hba = hba;
    t = hba->transport;

    se_dev = kzalloc(sizeof(struct se_subsystem_dev), GFP_KERNEL);
    if (!se_dev) {
        pr_err("Unable to allocate memory for"
                " struct se_subsystem_dev\n");
        ret = -ENOMEM;
        goto out;
    }
    INIT_LIST_HEAD(&se_dev->t10_wwn.t10_vpd_list);
    spin_lock_init(&se_dev->t10_wwn.t10_vpd_lock);
    INIT_LIST_HEAD(&se_dev->t10_pr.registration_list);
    INIT_LIST_HEAD(&se_dev->t10_pr.aptpl_reg_list);
    spin_lock_init(&se_dev->t10_pr.registration_lock);
    spin_lock_init(&se_dev->t10_pr.aptpl_reg_lock);
    INIT_LIST_HEAD(&se_dev->t10_alua.tg_pt_gps_list);
    spin_lock_init(&se_dev->t10_alua.tg_pt_gps_lock);
    spin_lock_init(&se_dev->se_dev_lock);
    se_dev->t10_pr.pr_aptpl_buf_len = PR_APTPL_BUF_LEN;
    se_dev->t10_wwn.t10_sub_dev = se_dev;
    se_dev->t10_alua.t10_sub_dev = se_dev;
    se_dev->se_dev_attrib.da_sub_dev = se_dev;
    se_dev->se_dev_hba = hba;

    se_dev->se_dev_su_ptr = t->allocate_virtdevice(hba, "virt_lun0");
    if (!se_dev->se_dev_su_ptr) {
        pr_err("Unable to locate subsystem dependent pointer"
            " from allocate_virtdevice()\n");
        ret = -ENOMEM;
        goto out;
    }
    lun0_su_dev = se_dev;

    memset(buf, 0, 16);
    sprintf(buf, "rd_pages=8");
    t->set_configfs_dev_params(hba, se_dev, buf, sizeof(buf));

    dev = t->create_virtdevice(hba, se_dev, se_dev->se_dev_su_ptr);
    if (IS_ERR(dev)) {
        ret = PTR_ERR(dev);
        goto out;
    }
    se_dev->se_dev_ptr = dev;
    g_lun0_dev = dev;

    return 0;
out:
    lun0_su_dev = NULL;
    kfree(se_dev);
    if (lun0_hba) {
        core_delete_hba(lun0_hba);
        lun0_hba = NULL;
    }
    return ret;
}


void core_dev_release_virtual_lun0(void)
{
    struct se_hba *hba = lun0_hba;
    struct se_subsystem_dev *su_dev = lun0_su_dev;

    if (!hba)
        return;

    if (g_lun0_dev)
        se_free_virtual_device(g_lun0_dev, hba);

    kfree(su_dev);
    core_delete_hba(hba);
}