Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus

[linux-btrfs-devel.git] / drivers / target / target_core_device.c

/*******************************************************************************
 * 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 <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/delay.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/kthread.h>
#include <linux/in.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_device.h>
#include <target/target_core_tpg.h>
#include <target/target_core_transport.h>
#include <target/target_core_fabric_ops.h>

#include "target_core_alua.h"
#include "target_core_hba.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_orig_obj_ptr = se_cmd->se_lun->lun_se_dev;
                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_orig_obj_ptr = se_cmd->se_lun->lun_se_dev;
                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);

        /*
         * Add the iscsi_cmd_t to the struct se_lun's cmd list.  This list is used
         * for tracking state of struct se_cmds during LUN shutdown events.
         */
        spin_lock_irqsave(&se_lun->lun_cmd_lock, flags);
        list_add_tail(&se_cmd->se_lun_node, &se_lun->lun_cmd_list);
        atomic_set(&se_cmd->transport_lun_active, 1);
        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;
                se_cmd->se_orig_obj_ptr = se_cmd->se_dev;
        }
        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_update_device_list_for_node(lun, NULL, deve->mapped_lun,
                        TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg, 0);
                spin_lock_irq(&nacl->device_list_lock);
        }
        spin_unlock_irq(&nacl->device_list_lock);

        kfree(nacl->device_list);
        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;

        spin_lock_irq(&se_nacl->device_list_lock);
        deve = &se_nacl->device_list[se_cmd->orig_fe_lun];
        deve->deve_cmds--;
        spin_unlock_irq(&se_nacl->device_list_lock);
}

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_update_device_list_for_node():
 *
 *
 */
int core_update_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,
        int enable)
{
        struct se_port *port = lun->lun_sep;
        struct se_dev_entry *deve = &nacl->device_list[mapped_lun];
        int trans = 0;
        /*
         * 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.
         */
        if (!enable) {
                /*
                 * deve->se_lun_acl will be NULL for demo-mode created LUNs
                 * that have not been explicitly concerted 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);
        }

        spin_lock_irq(&nacl->device_list_lock);
        if (enable) {
                /*
                 * 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;
                        trans = 1;
                } else {
                        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;
                }

                if (trans) {
                        spin_unlock_irq(&nacl->device_list_lock);
                        return 0;
                }
                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;
        }
        /*
         * Wait for any in process SPEC_I_PT=1 or REGISTER_AND_MOVE
         * PR operation to complete.
         */
        spin_unlock_irq(&nacl->device_list_lock);
        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_update_device_list_for_node(lun, NULL,
                                deve->mapped_lun, TRANSPORT_LUNFLAGS_NO_ACCESS,
                                nacl, tpg, 0);

                        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 IDENTIFER 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 IDENTIFER 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 IDENTIFER */
}

/*
 *      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 transport_core_report_lun_response(struct se_cmd *se_cmd)
{
        struct se_dev_entry *deve;
        struct se_lun *se_lun;
        struct se_session *se_sess = se_cmd->se_sess;
        struct se_task *se_task;
        unsigned char *buf;
        u32 cdb_offset = 0, lun_count = 0, offset = 8, i;

        list_for_each_entry(se_task, &se_cmd->t_task_list, t_list)
                break;

        if (!se_task) {
                pr_err("Unable to locate struct se_task for struct se_cmd\n");
                return PYX_TRANSPORT_LU_COMM_FAILURE;
        }

        buf = transport_kmap_first_data_page(se_cmd);

        /*
         * 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;
                se_lun = deve->se_lun;
                /*
                 * We determine the correct LUN LIST LENGTH even once we
                 * have reached the initial allocation length.
                 * See SPC2-R20 7.19.
                 */
                lun_count++;
                if ((cdb_offset + 8) >= se_cmd->data_length)
                        continue;

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

        /*
         * See SPC3 r07, page 159.
         */
done:
        transport_kunmap_first_data_page(se_cmd);
        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);

        return PYX_TRANSPORT_SENT_TO_TRANSPORT;
}

/*      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) {
                kthread_stop(dev->process_thread);
                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;
}

u32 se_dev_align_max_sectors(u32 max_sectors, u32 block_size)
{
        u32 tmp, aligned_max_sectors;
        /*
         * Limit max_sectors to a PAGE_SIZE aligned value for modern
         * transport_allocate_data_tasks() operation.
         */
        tmp = rounddown((max_sectors * block_size), PAGE_SIZE);
        aligned_max_sectors = (tmp / block_size);
        if (max_sectors != aligned_max_sectors) {
                printk(KERN_INFO "Rounding down aligned max_sectors from %u"
                                " to %u\n", max_sectors, aligned_max_sectors);
                return aligned_max_sectors;
        }

        return 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;
        /*
         * max_sectors is based on subsystem plugin dependent requirements.
         */
        dev->se_sub_dev->se_dev_attrib.hw_max_sectors = limits->max_hw_sectors;
        /*
         * Align max_sectors down to PAGE_SIZE to follow transport_allocate_data_tasks()
         */
        limits->max_sectors = se_dev_align_max_sectors(limits->max_sectors,
                                                limits->logical_block_size);
        dev->se_sub_dev->se_dev_attrib.max_sectors = limits->max_sectors;
        /*
         * Set optimal_sectors from max_sectors, which can be lowered via
         * configfs.
         */
        dev->se_sub_dev->se_dev_attrib.optimal_sectors = limits->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_task_timeout(struct se_device *dev, u32 task_timeout)
{
        if (task_timeout > DA_TASK_TIMEOUT_MAX) {
                pr_err("dev[%p]: Passed task_timeout: %u larger then"
                        " DA_TASK_TIMEOUT_MAX\n", dev, task_timeout);
                return -EINVAL;
        } else {
                dev->se_sub_dev->se_dev_attrib.task_timeout = task_timeout;
                pr_debug("dev[%p]: Set SE Device task_timeout: %u\n",
                        dev, task_timeout);
        }

        return 0;
}

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 (dev->transport->dpo_emulated == NULL) {
                pr_err("dev->transport->dpo_emulated is NULL\n");
                return -EINVAL;
        }
        if (dev->transport->dpo_emulated(dev) == 0) {
                pr_err("dev->transport->dpo_emulated not supported\n");
                return -EINVAL;
        }
        dev->se_sub_dev->se_dev_attrib.emulate_dpo = flag;
        pr_debug("dev[%p]: SE Device Page Out (DPO) Emulation"
                        " bit: %d\n", dev, dev->se_sub_dev->se_dev_attrib.emulate_dpo);
        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 (dev->transport->fua_write_emulated == NULL) {
                pr_err("dev->transport->fua_write_emulated is NULL\n");
                return -EINVAL;
        }
        if (dev->transport->fua_write_emulated(dev) == 0) {
                pr_err("dev->transport->fua_write_emulated not supported\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 (dev->transport->fua_read_emulated == NULL) {
                pr_err("dev->transport->fua_read_emulated is NULL\n");
                return -EINVAL;
        }
        if (dev->transport->fua_read_emulated(dev) == 0) {
                pr_err("dev->transport->fua_read_emulated not supported\n");
                return -EINVAL;
        }
        dev->se_sub_dev->se_dev_attrib.emulate_fua_read = flag;
        pr_debug("dev[%p]: SE Device Forced Unit Access READs: %d\n",
                        dev, dev->se_sub_dev->se_dev_attrib.emulate_fua_read);
        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 (dev->transport->write_cache_emulated == NULL) {
                pr_err("dev->transport->write_cache_emulated is NULL\n");
                return -EINVAL;
        }
        if (dev->transport->write_cache_emulated(dev) == 0) {
                pr_err("dev->transport->write_cache_emulated not supported\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 (!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 (!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)
{
        u32 orig_queue_depth = dev->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;
        if (queue_depth > orig_queue_depth)
                atomic_add(queue_depth - orig_queue_depth, &dev->depth_left);
        else if (queue_depth < orig_queue_depth)
                atomic_sub(orig_queue_depth - queue_depth, &dev->depth_left);

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

int se_dev_set_max_sectors(struct se_device *dev, u32 max_sectors)
{
        int force = 0; /* Force setting for VDEVS */

        if (atomic_read(&dev->dev_export_obj.obj_access_count)) {
                pr_err("dev[%p]: Unable to change SE Device"
                        " max_sectors while dev_export_obj: %d count exists\n",
                        dev, atomic_read(&dev->dev_export_obj.obj_access_count));
                return -EINVAL;
        }
        if (!max_sectors) {
                pr_err("dev[%p]: Illegal ZERO value for"
                        " max_sectors\n", dev);
                return -EINVAL;
        }
        if (max_sectors < DA_STATUS_MAX_SECTORS_MIN) {
                pr_err("dev[%p]: Passed max_sectors: %u less than"
                        " DA_STATUS_MAX_SECTORS_MIN: %u\n", dev, max_sectors,
                                DA_STATUS_MAX_SECTORS_MIN);
                return -EINVAL;
        }
        if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
                if (max_sectors > dev->se_sub_dev->se_dev_attrib.hw_max_sectors) {
                        pr_err("dev[%p]: Passed max_sectors: %u"
                                " greater than TCM/SE_Device max_sectors:"
                                " %u\n", dev, max_sectors,
                                dev->se_sub_dev->se_dev_attrib.hw_max_sectors);
                         return -EINVAL;
                }
        } else {
                if (!force && (max_sectors >
                                 dev->se_sub_dev->se_dev_attrib.hw_max_sectors)) {
                        pr_err("dev[%p]: Passed max_sectors: %u"
                                " greater than TCM/SE_Device max_sectors"
                                ": %u, use force=1 to override.\n", dev,
                                max_sectors, dev->se_sub_dev->se_dev_attrib.hw_max_sectors);
                        return -EINVAL;
                }
                if (max_sectors > DA_STATUS_MAX_SECTORS_MAX) {
                        pr_err("dev[%p]: Passed max_sectors: %u"
                                " greater than DA_STATUS_MAX_SECTORS_MAX:"
                                " %u\n", dev, max_sectors,
                                DA_STATUS_MAX_SECTORS_MAX);
                        return -EINVAL;
                }
        }
        /*
         * Align max_sectors down to PAGE_SIZE to follow transport_allocate_data_tasks()
         */
        max_sectors = se_dev_align_max_sectors(max_sectors,
                                dev->se_sub_dev->se_dev_attrib.block_size);

        dev->se_sub_dev->se_dev_attrib.max_sectors = max_sectors;
        pr_debug("dev[%p]: SE Device max_sectors changed to %u\n",
                        dev, 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.max_sectors) {
                pr_err("dev[%p]: Passed optimal_sectors %u cannot be"
                        " greater than max_sectors: %u\n", dev,
                        optimal_sectors, dev->se_sub_dev->se_dev_attrib.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_hba *hba,
        struct se_device *dev,
        u32 lun)
{
        struct se_lun *lun_p;
        u32 lun_access = 0;

        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 NULL;
        }

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

        if (dev->dev_flags & DF_READ_ONLY)
                lun_access = TRANSPORT_LUNFLAGS_READ_ONLY;
        else
                lun_access = TRANSPORT_LUNFLAGS_READ_WRITE;

        if (core_tpg_post_addlun(tpg, lun_p, lun_access, dev) < 0)
                return NULL;

        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(), 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;
        int ret = 0;

        lun = core_tpg_pre_dellun(tpg, unpacked_lun, &ret);
        if (!lun)
                return ret;

        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_update_device_list_for_node(lun, lacl, lacl->mapped_lun,
                        lun_access, nacl, tpg, 1) < 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_update_device_list_for_node(lun, NULL, lacl->mapped_lun,
                TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg, 0);

        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->se_dev_node);
        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);
}