/*******************************************************************************
 * Filename:  target_core_transport.c
 *
 * This file contains the Generic Target Engine Core.
 *
 * Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc.
 * Copyright (c) 2005, 2006, 2007 SBE, Inc.
 * Copyright (c) 2007-2010 Rising Tide Systems
 * Copyright (c) 2008-2010 Linux-iSCSI.org
 *
 * Nicholas A. Bellinger <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/delay.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/spinlock.h>
#include <linux/kthread.h>
#include <linux/in.h>
#include <linux/cdrom.h>
#include <linux/module.h>
#include <asm/unaligned.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_tcq.h>

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

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

static int sub_api_initialized;

static struct workqueue_struct *target_completion_wq;
static struct kmem_cache *se_sess_cache;
struct kmem_cache *se_tmr_req_cache;
struct kmem_cache *se_ua_cache;
struct kmem_cache *t10_pr_reg_cache;
struct kmem_cache *t10_alua_lu_gp_cache;
struct kmem_cache *t10_alua_lu_gp_mem_cache;
struct kmem_cache *t10_alua_tg_pt_gp_cache;
struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;

static int transport_generic_write_pending(struct se_cmd *);
static int transport_processing_thread(void *param);
static int __transport_execute_tasks(struct se_device *dev, struct se_cmd *);
static void transport_complete_task_attr(struct se_cmd *cmd);
static void transport_handle_queue_full(struct se_cmd *cmd,
                struct se_device *dev);
static void transport_free_dev_tasks(struct se_cmd *cmd);
static int transport_generic_get_mem(struct se_cmd *cmd);
static void transport_put_cmd(struct se_cmd *cmd);
static void transport_remove_cmd_from_queue(struct se_cmd *cmd);
static int transport_set_sense_codes(struct se_cmd *cmd, u8 asc, u8 ascq);
static void transport_generic_request_failure(struct se_cmd *);
static void target_complete_ok_work(struct work_struct *work);

int init_se_kmem_caches(void)
{
        se_tmr_req_cache = kmem_cache_create("se_tmr_cache",
                        sizeof(struct se_tmr_req), __alignof__(struct se_tmr_req),
                        0, NULL);
        if (!se_tmr_req_cache) {
                pr_err("kmem_cache_create() for struct se_tmr_req"
                                " failed\n");
                goto out;
        }
        se_sess_cache = kmem_cache_create("se_sess_cache",
                        sizeof(struct se_session), __alignof__(struct se_session),
                        0, NULL);
        if (!se_sess_cache) {
                pr_err("kmem_cache_create() for struct se_session"
                                " failed\n");
                goto out_free_tmr_req_cache;
        }
        se_ua_cache = kmem_cache_create("se_ua_cache",
                        sizeof(struct se_ua), __alignof__(struct se_ua),
                        0, NULL);
        if (!se_ua_cache) {
                pr_err("kmem_cache_create() for struct se_ua failed\n");
                goto out_free_sess_cache;
        }
        t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
                        sizeof(struct t10_pr_registration),
                        __alignof__(struct t10_pr_registration), 0, NULL);
        if (!t10_pr_reg_cache) {
                pr_err("kmem_cache_create() for struct t10_pr_registration"
                                " failed\n");
                goto out_free_ua_cache;
        }
        t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
                        sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
                        0, NULL);
        if (!t10_alua_lu_gp_cache) {
                pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
                                " failed\n");
                goto out_free_pr_reg_cache;
        }
        t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
                        sizeof(struct t10_alua_lu_gp_member),
                        __alignof__(struct t10_alua_lu_gp_member), 0, NULL);
        if (!t10_alua_lu_gp_mem_cache) {
                pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
                                "cache failed\n");
                goto out_free_lu_gp_cache;
        }
        t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
                        sizeof(struct t10_alua_tg_pt_gp),
                        __alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
        if (!t10_alua_tg_pt_gp_cache) {
                pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
                                "cache failed\n");
                goto out_free_lu_gp_mem_cache;
        }
        t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
                        "t10_alua_tg_pt_gp_mem_cache",
                        sizeof(struct t10_alua_tg_pt_gp_member),
                        __alignof__(struct t10_alua_tg_pt_gp_member),
                        0, NULL);
        if (!t10_alua_tg_pt_gp_mem_cache) {
                pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
                                "mem_t failed\n");
                goto out_free_tg_pt_gp_cache;
        }

        target_completion_wq = alloc_workqueue("target_completion",
                                               WQ_MEM_RECLAIM, 0);
        if (!target_completion_wq)
                goto out_free_tg_pt_gp_mem_cache;

        return 0;

out_free_tg_pt_gp_mem_cache:
        kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
out_free_tg_pt_gp_cache:
        kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
out_free_lu_gp_mem_cache:
        kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
out_free_lu_gp_cache:
        kmem_cache_destroy(t10_alua_lu_gp_cache);
out_free_pr_reg_cache:
        kmem_cache_destroy(t10_pr_reg_cache);
out_free_ua_cache:
        kmem_cache_destroy(se_ua_cache);
out_free_sess_cache:
        kmem_cache_destroy(se_sess_cache);
out_free_tmr_req_cache:
        kmem_cache_destroy(se_tmr_req_cache);
out:
        return -ENOMEM;
}

void release_se_kmem_caches(void)
{
        destroy_workqueue(target_completion_wq);
        kmem_cache_destroy(se_tmr_req_cache);
        kmem_cache_destroy(se_sess_cache);
        kmem_cache_destroy(se_ua_cache);
        kmem_cache_destroy(t10_pr_reg_cache);
        kmem_cache_destroy(t10_alua_lu_gp_cache);
        kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
        kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
        kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
}

/* This code ensures unique mib indexes are handed out. */
static DEFINE_SPINLOCK(scsi_mib_index_lock);
static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];

/*
 * Allocate a new row index for the entry type specified
 */
u32 scsi_get_new_index(scsi_index_t type)
{
        u32 new_index;

        BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));

        spin_lock(&scsi_mib_index_lock);
        new_index = ++scsi_mib_index[type];
        spin_unlock(&scsi_mib_index_lock);

        return new_index;
}

static void transport_init_queue_obj(struct se_queue_obj *qobj)
{
        atomic_set(&qobj->queue_cnt, 0);
        INIT_LIST_HEAD(&qobj->qobj_list);
        init_waitqueue_head(&qobj->thread_wq);
        spin_lock_init(&qobj->cmd_queue_lock);
}

void transport_subsystem_check_init(void)
{
        int ret;

        if (sub_api_initialized)
                return;

        ret = request_module("target_core_iblock");
        if (ret != 0)
                pr_err("Unable to load target_core_iblock\n");

        ret = request_module("target_core_file");
        if (ret != 0)
                pr_err("Unable to load target_core_file\n");

        ret = request_module("target_core_pscsi");
        if (ret != 0)
                pr_err("Unable to load target_core_pscsi\n");

        ret = request_module("target_core_stgt");
        if (ret != 0)
                pr_err("Unable to load target_core_stgt\n");

        sub_api_initialized = 1;
        return;
}

struct se_session *transport_init_session(void)
{
        struct se_session *se_sess;

        se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
        if (!se_sess) {
                pr_err("Unable to allocate struct se_session from"
                                " se_sess_cache\n");
                return ERR_PTR(-ENOMEM);
        }
        INIT_LIST_HEAD(&se_sess->sess_list);
        INIT_LIST_HEAD(&se_sess->sess_acl_list);
        INIT_LIST_HEAD(&se_sess->sess_cmd_list);
        INIT_LIST_HEAD(&se_sess->sess_wait_list);
        spin_lock_init(&se_sess->sess_cmd_lock);

        return se_sess;
}
EXPORT_SYMBOL(transport_init_session);

/*
 * Called with spin_lock_bh(&struct se_portal_group->session_lock called.
 */
void __transport_register_session(
        struct se_portal_group *se_tpg,
        struct se_node_acl *se_nacl,
        struct se_session *se_sess,
        void *fabric_sess_ptr)
{
        unsigned char buf[PR_REG_ISID_LEN];

        se_sess->se_tpg = se_tpg;
        se_sess->fabric_sess_ptr = fabric_sess_ptr;
        /*
         * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
         *
         * Only set for struct se_session's that will actually be moving I/O.
         * eg: *NOT* discovery sessions.
         */
        if (se_nacl) {
                /*
                 * If the fabric module supports an ISID based TransportID,
                 * save this value in binary from the fabric I_T Nexus now.
                 */
                if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
                        memset(&buf[0], 0, PR_REG_ISID_LEN);
                        se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
                                        &buf[0], PR_REG_ISID_LEN);
                        se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
                }
                spin_lock_irq(&se_nacl->nacl_sess_lock);
                /*
                 * The se_nacl->nacl_sess pointer will be set to the
                 * last active I_T Nexus for each struct se_node_acl.
                 */
                se_nacl->nacl_sess = se_sess;

                list_add_tail(&se_sess->sess_acl_list,
                              &se_nacl->acl_sess_list);
                spin_unlock_irq(&se_nacl->nacl_sess_lock);
        }
        list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);

        pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
                se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
}
EXPORT_SYMBOL(__transport_register_session);

void transport_register_session(
        struct se_portal_group *se_tpg,
        struct se_node_acl *se_nacl,
        struct se_session *se_sess,
        void *fabric_sess_ptr)
{
        spin_lock_bh(&se_tpg->session_lock);
        __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
        spin_unlock_bh(&se_tpg->session_lock);
}
EXPORT_SYMBOL(transport_register_session);

void transport_deregister_session_configfs(struct se_session *se_sess)
{
        struct se_node_acl *se_nacl;
        unsigned long flags;
        /*
         * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
         */
        se_nacl = se_sess->se_node_acl;
        if (se_nacl) {
                spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
                list_del(&se_sess->sess_acl_list);
                /*
                 * If the session list is empty, then clear the pointer.
                 * Otherwise, set the struct se_session pointer from the tail
                 * element of the per struct se_node_acl active session list.
                 */
                if (list_empty(&se_nacl->acl_sess_list))
                        se_nacl->nacl_sess = NULL;
                else {
                        se_nacl->nacl_sess = container_of(
                                        se_nacl->acl_sess_list.prev,
                                        struct se_session, sess_acl_list);
                }
                spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
        }
}
EXPORT_SYMBOL(transport_deregister_session_configfs);

void transport_free_session(struct se_session *se_sess)
{
        kmem_cache_free(se_sess_cache, se_sess);
}
EXPORT_SYMBOL(transport_free_session);

void transport_deregister_session(struct se_session *se_sess)
{
        struct se_portal_group *se_tpg = se_sess->se_tpg;
        struct se_node_acl *se_nacl;
        unsigned long flags;

        if (!se_tpg) {
                transport_free_session(se_sess);
                return;
        }

        spin_lock_irqsave(&se_tpg->session_lock, flags);
        list_del(&se_sess->sess_list);
        se_sess->se_tpg = NULL;
        se_sess->fabric_sess_ptr = NULL;
        spin_unlock_irqrestore(&se_tpg->session_lock, flags);

        /*
         * Determine if we need to do extra work for this initiator node's
         * struct se_node_acl if it had been previously dynamically generated.
         */
        se_nacl = se_sess->se_node_acl;
        if (se_nacl) {
                spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
                if (se_nacl->dynamic_node_acl) {
                        if (!se_tpg->se_tpg_tfo->tpg_check_demo_mode_cache(
                                        se_tpg)) {
                                list_del(&se_nacl->acl_list);
                                se_tpg->num_node_acls--;
                                spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);

                                core_tpg_wait_for_nacl_pr_ref(se_nacl);
                                core_free_device_list_for_node(se_nacl, se_tpg);
                                se_tpg->se_tpg_tfo->tpg_release_fabric_acl(se_tpg,
                                                se_nacl);
                                spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
                        }
                }
                spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
        }

        transport_free_session(se_sess);

        pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
                se_tpg->se_tpg_tfo->get_fabric_name());
}
EXPORT_SYMBOL(transport_deregister_session);

/*
 * Called with cmd->t_state_lock held.
 */
static void transport_all_task_dev_remove_state(struct se_cmd *cmd)
{
        struct se_device *dev = cmd->se_dev;
        struct se_task *task;
        unsigned long flags;

        if (!dev)
                return;

        list_for_each_entry(task, &cmd->t_task_list, t_list) {
                if (task->task_flags & TF_ACTIVE)
                        continue;

                spin_lock_irqsave(&dev->execute_task_lock, flags);
                if (task->t_state_active) {
                        pr_debug("Removed ITT: 0x%08x dev: %p task[%p]\n",
                                cmd->se_tfo->get_task_tag(cmd), dev, task);

                        list_del(&task->t_state_list);
                        atomic_dec(&cmd->t_task_cdbs_ex_left);
                        task->t_state_active = false;
                }
                spin_unlock_irqrestore(&dev->execute_task_lock, flags);
        }

}

/*      transport_cmd_check_stop():
 *
 *      'transport_off = 1' determines if t_transport_active should be cleared.
 *      'transport_off = 2' determines if task_dev_state should be removed.
 *
 *      A non-zero u8 t_state sets cmd->t_state.
 *      Returns 1 when command is stopped, else 0.
 */
static int transport_cmd_check_stop(
        struct se_cmd *cmd,
        int transport_off,
        u8 t_state)
{
        unsigned long flags;

        spin_lock_irqsave(&cmd->t_state_lock, flags);
        /*
         * Determine if IOCTL context caller in requesting the stopping of this
         * command for LUN shutdown purposes.
         */
        if (atomic_read(&cmd->transport_lun_stop)) {
                pr_debug("%s:%d atomic_read(&cmd->transport_lun_stop)"
                        " == TRUE for ITT: 0x%08x\n", __func__, __LINE__,
                        cmd->se_tfo->get_task_tag(cmd));

                atomic_set(&cmd->t_transport_active, 0);
                if (transport_off == 2)
                        transport_all_task_dev_remove_state(cmd);
                spin_unlock_irqrestore(&cmd->t_state_lock, flags);

                complete(&cmd->transport_lun_stop_comp);
                return 1;
        }
        /*
         * Determine if frontend context caller is requesting the stopping of
         * this command for frontend exceptions.
         */
        if (atomic_read(&cmd->t_transport_stop)) {
                pr_debug("%s:%d atomic_read(&cmd->t_transport_stop) =="
                        " TRUE for ITT: 0x%08x\n", __func__, __LINE__,
                        cmd->se_tfo->get_task_tag(cmd));

                if (transport_off == 2)
                        transport_all_task_dev_remove_state(cmd);

                /*
                 * Clear struct se_cmd->se_lun before the transport_off == 2 handoff
                 * to FE.
                 */
                if (transport_off == 2)
                        cmd->se_lun = NULL;
                spin_unlock_irqrestore(&cmd->t_state_lock, flags);

                complete(&cmd->t_transport_stop_comp);
                return 1;
        }
        if (transport_off) {
                atomic_set(&cmd->t_transport_active, 0);
                if (transport_off == 2) {
                        transport_all_task_dev_remove_state(cmd);
                        /*
                         * Clear struct se_cmd->se_lun before the transport_off == 2
                         * handoff to fabric module.
                         */
                        cmd->se_lun = NULL;
                        /*
                         * Some fabric modules like tcm_loop can release
                         * their internally allocated I/O reference now and
                         * struct se_cmd now.
                         *
                         * Fabric modules are expected to return '1' here if the
                         * se_cmd being passed is released at this point,
                         * or zero if not being released.
                         */
                        if (cmd->se_tfo->check_stop_free != NULL) {
                                spin_unlock_irqrestore(
                                        &cmd->t_state_lock, flags);

                                return cmd->se_tfo->check_stop_free(cmd);
                        }
                }
                spin_unlock_irqrestore(&cmd->t_state_lock, flags);

                return 0;
        } else if (t_state)
                cmd->t_state = t_state;
        spin_unlock_irqrestore(&cmd->t_state_lock, flags);

        return 0;
}

static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
{
        return transport_cmd_check_stop(cmd, 2, 0);
}

static void transport_lun_remove_cmd(struct se_cmd *cmd)
{
        struct se_lun *lun = cmd->se_lun;
        unsigned long flags;

        if (!lun)
                return;

        spin_lock_irqsave(&cmd->t_state_lock, flags);
        if (!atomic_read(&cmd->transport_dev_active)) {
                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
                goto check_lun;
        }
        atomic_set(&cmd->transport_dev_active, 0);
        transport_all_task_dev_remove_state(cmd);
        spin_unlock_irqrestore(&cmd->t_state_lock, flags);


check_lun:
        spin_lock_irqsave(&lun->lun_cmd_lock, flags);
        if (atomic_read(&cmd->transport_lun_active)) {
                list_del(&cmd->se_lun_node);
                atomic_set(&cmd->transport_lun_active, 0);
#if 0
                pr_debug("Removed ITT: 0x%08x from LUN LIST[%d]\n"
                        cmd->se_tfo->get_task_tag(cmd), lun->unpacked_lun);
#endif
        }
        spin_unlock_irqrestore(&lun->lun_cmd_lock, flags);
}

void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
{
        if (!cmd->se_tmr_req)
                transport_lun_remove_cmd(cmd);

        if (transport_cmd_check_stop_to_fabric(cmd))
                return;
        if (remove) {
                transport_remove_cmd_from_queue(cmd);
                transport_put_cmd(cmd);
        }
}

static void transport_add_cmd_to_queue(struct se_cmd *cmd, int t_state,
                bool at_head)
{
        struct se_device *dev = cmd->se_dev;
        struct se_queue_obj *qobj = &dev->dev_queue_obj;
        unsigned long flags;

        if (t_state) {
                spin_lock_irqsave(&cmd->t_state_lock, flags);
                cmd->t_state = t_state;
                atomic_set(&cmd->t_transport_active, 1);
                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
        }

        spin_lock_irqsave(&qobj->cmd_queue_lock, flags);

        /* If the cmd is already on the list, remove it before we add it */
        if (!list_empty(&cmd->se_queue_node))
                list_del(&cmd->se_queue_node);
        else
                atomic_inc(&qobj->queue_cnt);

        if (at_head)
                list_add(&cmd->se_queue_node, &qobj->qobj_list);
        else
                list_add_tail(&cmd->se_queue_node, &qobj->qobj_list);
        atomic_set(&cmd->t_transport_queue_active, 1);
        spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);

        wake_up_interruptible(&qobj->thread_wq);
}

static struct se_cmd *
transport_get_cmd_from_queue(struct se_queue_obj *qobj)
{
        struct se_cmd *cmd;
        unsigned long flags;

        spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
        if (list_empty(&qobj->qobj_list)) {
                spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
                return NULL;
        }
        cmd = list_first_entry(&qobj->qobj_list, struct se_cmd, se_queue_node);

        atomic_set(&cmd->t_transport_queue_active, 0);

        list_del_init(&cmd->se_queue_node);
        atomic_dec(&qobj->queue_cnt);
        spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);

        return cmd;
}

static void transport_remove_cmd_from_queue(struct se_cmd *cmd)
{
        struct se_queue_obj *qobj = &cmd->se_dev->dev_queue_obj;
        unsigned long flags;

        spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
        if (!atomic_read(&cmd->t_transport_queue_active)) {
                spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
                return;
        }
        atomic_set(&cmd->t_transport_queue_active, 0);
        atomic_dec(&qobj->queue_cnt);
        list_del_init(&cmd->se_queue_node);
        spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);

        if (atomic_read(&cmd->t_transport_queue_active)) {
                pr_err("ITT: 0x%08x t_transport_queue_active: %d\n",
                        cmd->se_tfo->get_task_tag(cmd),
                        atomic_read(&cmd->t_transport_queue_active));
        }
}

/*
 * Completion function used by TCM subsystem plugins (such as FILEIO)
 * for queueing up response from struct se_subsystem_api->do_task()
 */
void transport_complete_sync_cache(struct se_cmd *cmd, int good)
{
        struct se_task *task = list_entry(cmd->t_task_list.next,
                                struct se_task, t_list);

        if (good) {
                cmd->scsi_status = SAM_STAT_GOOD;
                task->task_scsi_status = GOOD;
        } else {
                task->task_scsi_status = SAM_STAT_CHECK_CONDITION;
                task->task_se_cmd->scsi_sense_reason =
                                TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;

        }

        transport_complete_task(task, good);
}
EXPORT_SYMBOL(transport_complete_sync_cache);

static void target_complete_failure_work(struct work_struct *work)
{
        struct se_cmd *cmd = container_of(work, struct se_cmd, work);

        transport_generic_request_failure(cmd);
}

/*      transport_complete_task():
 *
 *      Called from interrupt and non interrupt context depending
 *      on the transport plugin.
 */
void transport_complete_task(struct se_task *task, int success)
{
        struct se_cmd *cmd = task->task_se_cmd;
        struct se_device *dev = cmd->se_dev;
        unsigned long flags;

        spin_lock_irqsave(&cmd->t_state_lock, flags);
        task->task_flags &= ~TF_ACTIVE;

        /*
         * See if any sense data exists, if so set the TASK_SENSE flag.
         * Also check for any other post completion work that needs to be
         * done by the plugins.
         */
        if (dev && dev->transport->transport_complete) {
                if (dev->transport->transport_complete(task) != 0) {
                        cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
                        task->task_flags |= TF_HAS_SENSE;
                        success = 1;
                }
        }

        /*
         * See if we are waiting for outstanding struct se_task
         * to complete for an exception condition
         */
        if (task->task_flags & TF_REQUEST_STOP) {
                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
                complete(&task->task_stop_comp);
                return;
        }

        if (!success)
                cmd->t_tasks_failed = 1;

        /*
         * Decrement the outstanding t_task_cdbs_left count.  The last
         * struct se_task from struct se_cmd will complete itself into the
         * device queue depending upon int success.
         */
        if (!atomic_dec_and_test(&cmd->t_task_cdbs_left)) {
                spin_unlock_irqrestore(&cmd->t_state_lock, flags);
                return;
        }

        if (cmd->t_tasks_failed) {
                cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
                INIT_WORK(&cmd->work, target_complete_failure_work);
        } else {
                atomic_set(&cmd->t_transport_complete, 1);
                INIT_WORK(&cmd->work, target_complete_ok_work);
        }

        cmd->t_state = TRANSPORT_COMPLETE;
        atomic_set(&cmd->t_transport_active, 1);
        spin_unlock_irqrestore(&cmd->t_state_lock, flags);

        queue_work(target_completion_wq, &cmd->work);
}
EXPORT_SYMBOL(transport_complete_task);

/*
 * Called by transport_add_tasks_from_cmd() once a struct se_cmd's
 * struct se_task list are ready to be added to the active execution list
 * struct se_device

 * Called with se_dev_t->execute_task_lock called.
 */
static inline int transport_add_task_check_sam_attr(
        struct se_task *task,
        struct se_task *task_prev,
        struct se_device *dev)
{
        /*
         * No SAM Task attribute emulation enabled, add to tail of
         * execution queue
         */
        if (dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED) {
                list_add_tail(&task->t_execute_list, &dev->execute_task_list);
                return 0;
        }
        /*
         * HEAD_OF_QUEUE attribute for received CDB, which means
         * the first task that is associated with a struct se_cmd goes to
         * head of the struct se_device->execute_task_list, and task_prev
         * after that for each subsequent task
         */
        if (task->task_se_cmd->sam_task_attr == MSG_HEAD_TAG) {
                list_add(&task->t_execute_list,
                                (task_prev != NULL) ?
                                &task_prev->t_execute_list :
                                &dev->execute_task_list);

                pr_debug("Set HEAD_OF_QUEUE for task CDB: 0x%02x"
                                " in execution queue\n",
                                task->task_se_cmd->t_task_cdb[0]);
                return 1;
        }
        /*
         * For ORDERED, SIMPLE or UNTAGGED attribute tasks once they have been
         * transitioned from Dermant -> Active state, and are added to the end
         * of the struct se_device->execute_task_list
         */
        list_add_tail(&task->t_execute_list, &dev->execute_task_list);
        return 0;
}

/*      __transport_add_task_to_execute_queue():
 *
 *      Called with se_dev_t->execute_task_lock called.
 */
static void __transport_add_task_to_execute_queue(
        struct se_task *task,
        struct se_task *task_prev,
        struct se_device *dev)
{
        int head_of_queue;

        head_of_queue = transport_add_task_check_sam_attr(task, task_prev, dev);
        atomic_inc(&dev->execute_tasks);

        if (task->t_state_active)
                return;
        /*
         * Determine if this task needs to go to HEAD_OF_QUEUE for the
         * state list as well.  Running with SAM Task Attribute emulation
         * will always return head_of_queue == 0 here
         */
        if (head_of_queue)
                list_add(&task->t_state_list, (task_prev) ?
                                &task_prev->t_state_list :
                                &dev->state_task_list);
        else
                list_add_tail(&task->t_state_list, &dev->state_task_list);

        task->t_state_active = true;

        pr_debug("Added ITT: 0x%08x task[%p] to dev: %p\n",
                task->task_se_cmd->se_tfo->get_task_tag(task->task_se_cmd),
                task, dev);
}

static void transport_add_tasks_to_state_queue(struct se_cmd *cmd)
{
        struct se_device *dev = cmd->se_dev;
        struct se_task *task;
        unsigned long flags;

        spin_lock_irqsave(&cmd->t_state_lock, flags);
        list_for_each_entry(task, &cmd->t_task_list, t_list) {
                spin_lock(&dev->execute_task_lock);
                if (!task->t_state_active) {
                        list_add_tail(&task->t_state_list,
                                      &dev->state_task_list);
                        task->t_state_active = true;

                        pr_debug("Added ITT: 0x%08x task[%p] to dev: %p\n",
                                task->task_se_cmd->se_tfo->get_task_tag(
                                task->task_se_cmd), task, dev);
                }
                spin_unlock(&dev->execute_task_lock);
        }
        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
}

static void __transport_add_tasks_from_cmd(struct se_cmd *cmd)
{
        struct se_device *dev = cmd->se_dev;
        struct se_task *task, *task_prev = NULL;

        list_for_each_entry(task, &cmd->t_task_list, t_list) {
                if (!list_empty(&task->t_execute_list))
                        continue;
                /*
                 * __transport_add_task_to_execute_queue() handles the
                 * SAM Task Attribute emulation if enabled
                 */
                __transport_add_task_to_execute_queue(task, task_prev, dev);
                task_prev = task;
        }
}

static void transport_add_tasks_from_cmd(struct se_cmd *cmd)
{
        unsigned long flags;
        struct se_device *dev = cmd->se_dev;

        spin_lock_irqsave(&dev->execute_task_lock, flags);
        __transport_add_tasks_from_cmd(cmd);
        spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}

void __transport_remove_task_from_execute_queue(struct se_task *task,
                struct se_device *dev)
{
        list_del_init(&task->t_execute_list);
        atomic_dec(&dev->execute_tasks);
}

static void transport_remove_task_from_execute_queue(
        struct se_task *task,
        struct se_device *dev)
{
        unsigned long flags;

        if (WARN_ON(list_empty(&task->t_execute_list)))
                return;

        spin_lock_irqsave(&dev->execute_task_lock, flags);
        __transport_remove_task_from_execute_queue(task, dev);
        spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}

/*
 * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
 */

static void target_qf_do_work(struct work_struct *work)
{
        struct se_device *dev = container_of(work, struct se_device,
                                        qf_work_queue);
        LIST_HEAD(qf_cmd_list);
        struct se_cmd *cmd, *cmd_tmp;

        spin_lock_irq(&dev->qf_cmd_lock);
        list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
        spin_unlock_irq(&dev->qf_cmd_lock);

        list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
                list_del(&cmd->se_qf_node);
                atomic_dec(&dev->dev_qf_count);
                smp_mb__after_atomic_dec();

                pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
                        " context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
                        (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
                        (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
                        : "UNKNOWN");

                transport_add_cmd_to_queue(cmd, cmd->t_state, true);
        }
}

unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
{
        switch (cmd->data_direction) {
        case DMA_NONE:
                return "NONE";
        case DMA_FROM_DEVICE:
                return "READ";
        case DMA_TO_DEVICE:
                return "WRITE";
        case DMA_BIDIRECTIONAL:
                return "BIDI";
        default:
                break;
        }

        return "UNKNOWN";
}

void transport_dump_dev_state(
        struct se_device *dev,
        char *b,
        int *bl)
{
        *bl += sprintf(b + *bl, "Status: ");
        switch (dev->dev_status) {
        case TRANSPORT_DEVICE_ACTIVATED:
                *bl += sprintf(b + *bl, "ACTIVATED");
                break;
        case TRANSPORT_DEVICE_DEACTIVATED:
                *bl += sprintf(b + *bl, "DEACTIVATED");
                break;
        case TRANSPORT_DEVICE_SHUTDOWN:
                *bl += sprintf(b + *bl, "SHUTDOWN");
                break;
        case TRANSPORT_DEVICE_OFFLINE_ACTIVATED:
        case TRANSPORT_DEVICE_OFFLINE_DEACTIVATED:
                *bl += sprintf(b + *bl, "OFFLINE");
                break;
        default:
                *bl += sprintf(b + *bl, "UNKNOWN=%d", dev->dev_status);
                break;
        }

        *bl += sprintf(b + *bl, "  Execute/Max Queue Depth: %d/%d",
                atomic_read(&dev->execute_tasks), dev->queue_depth);
        *bl += sprintf(b + *bl, "  SectorSize: %u  MaxSectors: %u\n",
                dev->se_sub_dev->se_dev_attrib.block_size, dev->se_sub_dev->se_dev_attrib.max_sectors);
        *bl += sprintf(b + *bl, "        ");
}

void transport_dump_vpd_proto_id(
        struct t10_vpd *vpd,
        unsigned char *p_buf,
        int p_buf_len)
{
        unsigned char buf[VPD_TMP_BUF_SIZE];
        int len;

        memset(buf, 0, VPD_TMP_BUF_SIZE);
        len = sprintf(buf, "T10 VPD Protocol Identifier: ");

        switch (vpd->protocol_identifier) {
        case 0x00:
                sprintf(buf+len, "Fibre Channel\n");
                break;
        case 0x10:
                sprintf(buf+len, "Parallel SCSI\n");
                break;
        case 0x20:

                sprintf(buf+len, "SSA\n");
                break;
        case 0x30:
                sprintf(buf+len, "IEEE 1394\n");
                break;
        case 0x40:
                sprintf(buf+len, "SCSI Remote Direct Memory Access"
                                " Protocol\n");
                break;
        case 0x50:
                sprintf(buf+len, "Internet SCSI (iSCSI)\n");
                break;
        case 0x60:
                sprintf(buf+len, "SAS Serial SCSI Protocol\n");
                break;
        case 0x70:
                sprintf(buf+len, "Automation/Drive Interface Transport"
                                " Protocol\n");
                break;
        case 0x80:
                sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
                break;
        default:
                sprintf(buf+len, "Unknown 0x%02x\n",
                                vpd->protocol_identifier);
                break;
        }

        if (p_buf)
                strncpy(p_buf, buf, p_buf_len);
        else
                pr_debug("%s", buf);
}

void
transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
{
        /*
         * Check if the Protocol Identifier Valid (PIV) bit is set..
         *
         * from spc3r23.pdf section 7.5.1
         */
         if (page_83[1] & 0x80) {
                vpd->protocol_identifier = (page_83[0] & 0xf0);
                vpd->protocol_identifier_set = 1;
                transport_dump_vpd_proto_id(vpd, NULL, 0);
        }
}
EXPORT_SYMBOL(transport_set_vpd_proto_id);

int transport_dump_vpd_assoc(
        struct t10_vpd *vpd,
        unsigned char *p_buf,
        int p_buf_len)
{
        unsigned char buf[VPD_TMP_BUF_SIZE];
        int ret = 0;
        int len;

        memset(buf, 0, VPD_TMP_BUF_SIZE);
        len = sprintf(buf, "T10 VPD Identifier Association: ");

        switch (vpd->association) {
        case 0x00:
                sprintf(buf+len, "addressed logical unit\n");
                break;
        case 0x10:
                sprintf(buf+len, "target port\n");
                break;
        case 0x20:
                sprintf(buf+len, "SCSI target device\n");
                break;
        default:
                sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
                ret = -EINVAL;
                break;
        }

        if (p_buf)
                strncpy(p_buf, buf, p_buf_len);
        else
                pr_debug("%s", buf);

        return ret;
}

int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
{
        /*
         * The VPD identification association..
         *
         * from spc3r23.pdf Section 7.6.3.1 Table 297
         */
        vpd->association = (page_83[1] & 0x30);
        return transport_dump_vpd_assoc(vpd, NULL, 0);
}
EXPORT_SYMBOL(transport_set_vpd_assoc);

int transport_dump_vpd_ident_type(
        struct t10_vpd *vpd,
        unsigned char *p_buf,
        int p_buf_len)
{
        unsigned char buf[VPD_TMP_BUF_SIZE];
        int ret = 0;
        int len;

        memset(buf, 0, VPD_TMP_BUF_SIZE);
        len = sprintf(buf, "T10 VPD Identifier Type: ");

        switch (vpd->device_identifier_type) {
        case 0x00:
                sprintf(buf+len, "Vendor specific\n");
                break;
        case 0x01:
                sprintf(buf+len, "T10 Vendor ID based\n");
                break;
        case 0x02:
                sprintf(buf+len, "EUI-64 based\n");
                break;
        case 0x03:
                sprintf(buf+len, "NAA\n");
                break;
        case 0x04:
                sprintf(buf+len, "Relative target port identifier\n");
                break;
        case 0x08:
                sprintf(buf+len, "SCSI name string\n");
                break;
        default:
                sprintf(buf+len, "Unsupported: 0x%02x\n",
                                vpd->device_identifier_type);
                ret = -EINVAL;
                break;
        }

        if (p_buf) {
                if (p_buf_len < strlen(buf)+1)
                        return -EINVAL;
                strncpy(p_buf, buf, p_buf_len);
        } else {
                pr_debug("%s", buf);
        }

        return ret;
}

int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
{
        /*
         * The VPD identifier type..
         *
         * from spc3r23.pdf Section 7.6.3.1 Table 298
         */
        vpd->device_identifier_type = (page_83[1] & 0x0f);
        return transport_dump_vpd_ident_type(vpd, NULL, 0);
}
EXPORT_SYMBOL(transport_set_vpd_ident_type);

int transport_dump_vpd_ident(
        struct t10_vpd *vpd,
        unsigned char *p_buf,
        int p_buf_len)
{
        unsigned char buf[VPD_TMP_BUF_SIZE];
        int ret = 0;

        memset(buf, 0, VPD_TMP_BUF_SIZE);

        switch (vpd->device_identifier_code_set) {
        case 0x01: /* Binary */
                sprintf(buf, "T10 VPD Binary Device Identifier: %s\n",
                        &vpd->device_identifier[0]);
                break;
        case 0x02: /* ASCII */
                sprintf(buf, "T10 VPD ASCII Device Identifier: %s\n",
                        &vpd->device_identifier[0]);
                break;
        case 0x03: /* UTF-8 */
                sprintf(buf, "T10 VPD UTF-8 Device Identifier: %s\n",
                        &vpd->device_identifier[0]);
                break;
        default:
                sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
                        " 0x%02x", vpd->device_identifier_code_set);
                ret = -EINVAL;
                break;
        }

        if (p_buf)
                strncpy(p_buf, buf, p_buf_len);
        else
                pr_debug("%s", buf);

        return ret;
}

int
transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
{
        static const char hex_str[] = "0123456789abcdef";
        int j = 0, i = 4; /* offset to start of the identifer */

        /*
         * The VPD Code Set (encoding)
         *
         * from spc3r23.pdf Section 7.6.3.1 Table 296
         */
        vpd->device_identifier_code_set = (page_83[0] & 0x0f);
        switch (vpd->device_identifier_code_set) {
        case 0x01: /* Binary */
                vpd->device_identifier[j++] =
                                hex_str[vpd->device_identifier_type];
                while (i < (4 + page_83[3])) {
                        vpd->device_identifier[j++] =
                                hex_str[(page_83[i] & 0xf0) >> 4];
                        vpd->device_identifier[j++] =
                                hex_str[page_83[i] & 0x0f];
                        i++;
                }
                break;
        case 0x02: /* ASCII */
        case 0x03: /* UTF-8 */
                while (i < (4 + page_83[3]))
                        vpd->device_identifier[j++] = page_83[i++];
                break;
        default:
                break;
        }

        return transport_dump_vpd_ident(vpd, NULL, 0);
}
EXPORT_SYMBOL(transport_set_vpd_ident);

static void core_setup_task_attr_emulation(struct se_device *dev)
{
        /*
         * If this device is from Target_Core_Mod/pSCSI, disable the
         * SAM Task Attribute emulation.
         *
         * This is currently not available in upsream Linux/SCSI Target
         * mode code, and is assumed to be disabled while using TCM/pSCSI.
         */
        if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
                dev->dev_task_attr_type = SAM_TASK_ATTR_PASSTHROUGH;
                return;
        }

        dev->dev_task_attr_type = SAM_TASK_ATTR_EMULATED;
        pr_debug("%s: Using SAM_TASK_ATTR_EMULATED for SPC: 0x%02x"
                " device\n", dev->transport->name,
                dev->transport->get_device_rev(dev));
}

static void scsi_dump_inquiry(struct se_device *dev)
{
        struct t10_wwn *wwn = &dev->se_sub_dev->t10_wwn;
        char buf[17];
        int i, device_type;
        /*
         * Print Linux/SCSI style INQUIRY formatting to the kernel ring buffer
         */
        for (i = 0; i < 8; i++)
                if (wwn->vendor[i] >= 0x20)
                        buf[i] = wwn->vendor[i];
                else
                        buf[i] = ' ';
        buf[i] = '\0';
        pr_debug("  Vendor: %s\n", buf);

        for (i = 0; i < 16; i++)
                if (wwn->model[i] >= 0x20)
                        buf[i] = wwn->model[i];
                else
                        buf[i] = ' ';
        buf[i] = '\0';
        pr_debug("  Model: %s\n", buf);

        for (i = 0; i < 4; i++)
                if (wwn->revision[i] >= 0x20)
                        buf[i] = wwn->revision[i];
                else
                        buf[i] = ' ';
        buf[i] = '\0';
        pr_debug("  Revision: %s\n", buf);

        device_type = dev->transport->get_device_type(dev);
        pr_debug("  Type:   %s ", scsi_device_type(device_type));
        pr_debug("                 ANSI SCSI revision: %02x\n",
                                dev->transport->get_device_rev(dev));
}

struct se_device *transport_add_device_to_core_hba(
        struct se_hba *hba,
        struct se_subsystem_api *transport,
        struct se_subsystem_dev *se_dev,
        u32 device_flags,
        void *transport_dev,
        struct se_dev_limits *dev_limits,
        const char *inquiry_prod,
        const char *inquiry_rev)
{
        int force_pt;
        struct se_device  *dev;

        dev = kzalloc(sizeof(struct se_device), GFP_KERNEL);
        if (!dev) {
                pr_err("Unable to allocate memory for se_dev_t\n");
                return NULL;
        }

        transport_init_queue_obj(&dev->dev_queue_obj);
        dev->dev_flags          = device_flags;
        dev->dev_status         |= TRANSPORT_DEVICE_DEACTIVATED;
        dev->dev_ptr            = transport_dev;
        dev->se_hba             = hba;
        dev->se_sub_dev         = se_dev;
        dev->transport          = transport;
        INIT_LIST_HEAD(&dev->dev_list);
        INIT_LIST_HEAD(&dev->dev_sep_list);
        INIT_LIST_HEAD(&dev->dev_tmr_list);
        INIT_LIST_HEAD(&dev->execute_task_list);
        INIT_LIST_HEAD(&dev->delayed_cmd_list);
        INIT_LIST_HEAD(&dev->state_task_list);
        INIT_LIST_HEAD(&dev->qf_cmd_list);
        spin_lock_init(&dev->execute_task_lock);
        spin_lock_init(&dev->delayed_cmd_lock);
        spin_lock_init(&dev->dev_reservation_lock);
        spin_lock_init(&dev->dev_status_lock);
        spin_lock_init(&dev->se_port_lock);
        spin_lock_init(&dev->se_tmr_lock);
        spin_lock_init(&dev->qf_cmd_lock);
        atomic_set(&dev->dev_ordered_id, 0);

        se_dev_set_default_attribs(dev, dev_limits);

        dev->dev_index = scsi_get_new_index(SCSI_DEVICE_INDEX);
        dev->creation_time = get_jiffies_64();
        spin_lock_init(&dev->stats_lock);

        spin_lock(&hba->device_lock);
        list_add_tail(&dev->dev_list, &hba->hba_dev_list);
        hba->dev_count++;
        spin_unlock(&hba->device_lock);
        /*
         * Setup the SAM Task Attribute emulation for struct se_device
         */
        core_setup_task_attr_emulation(dev);
        /*
         * Force PR and ALUA passthrough emulation with internal object use.
         */
        force_pt = (hba->hba_flags & HBA_FLAGS_INTERNAL_USE);
        /*
         * Setup the Reservations infrastructure for struct se_device
         */
        core_setup_reservations(dev, force_pt);
        /*
         * Setup the Asymmetric Logical Unit Assignment for struct se_device
         */
        if (core_setup_alua(dev, force_pt) < 0)
                goto out;

        /*
         * Startup the struct se_device processing thread
         */
        dev->process_thread = kthread_run(transport_processing_thread, dev,
                                          "LIO_%s", dev->transport->name);
        if (IS_ERR(dev->process_thread)) {
                pr_err("Unable to create kthread: LIO_%s\n",
                        dev->transport->name);
                goto out;
        }
        /*
         * Setup work_queue for QUEUE_FULL
         */
        INIT_WORK(&dev->qf_work_queue, target_qf_do_work);
        /*
         * Preload the initial INQUIRY const values if we are doing
         * anything virtual (IBLOCK, FILEIO, RAMDISK), but not for TCM/pSCSI
         * passthrough because this is being provided by the backend LLD.
         * This is required so that transport_get_inquiry() copies these
         * originals once back into DEV_T10_WWN(dev) for the virtual device
         * setup.
         */
        if (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV) {
                if (!inquiry_prod || !inquiry_rev) {
                        pr_err("All non TCM/pSCSI plugins require"
                                " INQUIRY consts\n");
                        goto out;
                }

                strncpy(&dev->se_sub_dev->t10_wwn.vendor[0], "LIO-ORG", 8);
                strncpy(&dev->se_sub_dev->t10_wwn.model[0], inquiry_prod, 16);
                strncpy(&dev->se_sub_dev->t10_wwn.revision[0], inquiry_rev, 4);
        }
        scsi_dump_inquiry(dev);

        return dev;
out:
        kthread_stop(dev->process_thread);

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

        se_release_vpd_for_dev(dev);

        kfree(dev);

        return NULL;
}
EXPORT_SYMBOL(transport_add_device_to_core_hba);

/*      transport_generic_prepare_cdb():
 *
 *      Since the Initiator sees iSCSI devices as LUNs,  the SCSI CDB will
 *      contain the iSCSI LUN in bits 7-5 of byte 1 as per SAM-2.
 *      The point of this is since we are mapping iSCSI LUNs to
 *      SCSI Target IDs having a non-zero LUN in the CDB will throw the
 *      devices and HBAs for a loop.
 */
static inline void transport_generic_prepare_cdb(
        unsigned char *cdb)
{
        switch (cdb[0]) {
        case READ_10: /* SBC - RDProtect */
        case READ_12: /* SBC - RDProtect */
        case READ_16: /* SBC - RDProtect */
        case SEND_DIAGNOSTIC: /* SPC - SELF-TEST Code */
        case VERIFY: /* SBC - VRProtect */
        case VERIFY_16: /* SBC - VRProtect */
        case WRITE_VERIFY: /* SBC - VRProtect */
        case WRITE_VERIFY_12: /* SBC - VRProtect */
                break;
        default:
                cdb[1] &= 0x1f; /* clear logical unit number */
                break;
        }
}

static struct se_task *
transport_generic_get_task(struct se_cmd *cmd,
                enum dma_data_direction data_direction)
{
        struct se_task *task;
        struct se_device *dev = cmd->se_dev;

        task = dev->transport->alloc_task(cmd->t_task_cdb);
        if (!task) {
                pr_err("Unable to allocate struct se_task\n");
                return NULL;
        }

        INIT_LIST_HEAD(&task->t_list);
        INIT_LIST_HEAD(&task->t_execute_list);
        INIT_LIST_HEAD(&task->t_state_list);
        init_completion(&task->task_stop_comp);
        task->task_se_cmd = cmd;
        task->task_data_direction = data_direction;

        return task;
}

static int transport_generic_cmd_sequencer(struct se_cmd *, unsigned char *);

/*
 * Used by fabric modules containing a local struct se_cmd within their
 * fabric dependent per I/O descriptor.
 */
void transport_init_se_cmd(
        struct se_cmd *cmd,
        struct target_core_fabric_ops *tfo,
        struct se_session *se_sess,
        u32 data_length,
        int data_direction,
        int task_attr,
        unsigned char *sense_buffer)
{
        INIT_LIST_HEAD(&cmd->se_lun_node);
        INIT_LIST_HEAD(&cmd->se_delayed_node);
        INIT_LIST_HEAD(&cmd->se_qf_node);
        INIT_LIST_HEAD(&cmd->se_queue_node);
        INIT_LIST_HEAD(&cmd->se_cmd_list);
        INIT_LIST_HEAD(&cmd->t_task_list);
        init_completion(&cmd->transport_lun_fe_stop_comp);
        init_completion(&cmd->transport_lun_stop_comp);
        init_completion(&cmd->t_transport_stop_comp);
        init_completion(&cmd->cmd_wait_comp);
        spin_lock_init(&cmd->t_state_lock);
        atomic_set(&cmd->transport_dev_active, 1);

        cmd->se_tfo = tfo;
        cmd->se_sess = se_sess;
        cmd->data_length = data_length;
        cmd->data_direction = data_direction;
        cmd->sam_task_attr = task_attr;
        cmd->sense_buffer = sense_buffer;
}
EXPORT_SYMBOL(transport_init_se_cmd);

static int transport_check_alloc_task_attr(struct se_cmd *cmd)
{
        /*
         * Check if SAM Task Attribute emulation is enabled for this
         * struct se_device storage object
         */
        if (cmd->se_dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
                return 0;

        if (cmd->sam_task_attr == MSG_ACA_TAG) {
                pr_debug("SAM Task Attribute ACA"
                        " emulation is not supported\n");
                return -EINVAL;
        }
        /*
         * Used to determine when ORDERED commands should go from
         * Dormant to Active status.
         */
        cmd->se_ordered_id = atomic_inc_return(&cmd->se_dev->dev_ordered_id);
        smp_mb__after_atomic_inc();
        pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
                        cmd->se_ordered_id, cmd->sam_task_attr,
                        cmd->se_dev->transport->name);
        return 0;
}

/*      transport_generic_allocate_tasks():
 *
 *      Called from fabric RX Thread.
 */
int transport_generic_allocate_tasks(
        struct se_cmd *cmd,
        unsigned char *cdb)
{
        int ret;

        transport_generic_prepare_cdb(cdb);
        /*
         * Ensure that the received CDB is less than the max (252 + 8) bytes
         * for VARIABLE_LENGTH_CMD
         */
        if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
                pr_err("Received SCSI CDB with command_size: %d that"
                        " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
                        scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
                cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
                cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
                return -EINVAL;
        }
        /*
         * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
         * allocate the additional extended CDB buffer now..  Otherwise
         * setup the pointer from __t_task_cdb to t_task_cdb.
         */
        if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
                cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
                                                GFP_KERNEL);
                if (!cmd->t_task_cdb) {
                        pr_err("Unable to allocate cmd->t_task_cdb"
                                " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
                                scsi_command_size(cdb),
                                (unsigned long)sizeof(cmd->__t_task_cdb));
                        cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
                        cmd->scsi_sense_reason =
                                        TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
                        return -ENOMEM;
                }
        } else
                cmd->t_task_cdb = &cmd->__t_task_cdb[0];
        /*
         * Copy the original CDB into cmd->
         */
        memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
        /*
         * Setup the received CDB based on SCSI defined opcodes and
         * perform unit attention, persistent reservations and ALUA
         * checks for virtual device backends.  The cmd->t_task_cdb
         * pointer is expected to be setup before we reach this point.
         */
        ret = transport_generic_cmd_sequencer(cmd, cdb);
        if (ret < 0)
                return ret;
        /*
         * Check for SAM Task Attribute Emulation
         */
        if (transport_check_alloc_task_attr(cmd) < 0) {
                cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
                cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
                return -EINVAL;
        }
        spin_lock(&cmd->se_lun->lun_sep_lock);
        if (cmd->se_lun->lun_sep)
                cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
        spin_unlock(&cmd->se_lun->lun_sep_lock);
        return 0;
}
EXPORT_SYMBOL(transport_generic_allocate_tasks);

/*
 * Used by fabric module frontends to queue tasks directly.
 * Many only be used from process context only
 */
int transport_handle_cdb_direct(
        struct se_cmd *cmd)
{
        int ret;

        if (!cmd->se_lun) {
                dump_stack();
                pr_err("cmd->se_lun is NULL\n");
                return -EINVAL;
        }
        if (in_interrupt()) {
                dump_stack();
                pr_err("transport_generic_handle_cdb cannot be called"
                                " from interrupt context\n");
                return -EINVAL;
        }
        /*
         * Set TRANSPORT_NEW_CMD state and cmd->t_transport_active=1 following
         * transport_generic_handle_cdb*() -> transport_add_cmd_to_queue()
         * in existing usage to ensure that outstanding descriptors are handled
         * correctly during shutdown via transport_wait_for_tasks()
         *
         * Also, we don't take cmd->t_state_lock here as we only expect
         * this to be called for initial descriptor submission.
         */
        cmd->t_state = TRANSPORT_NEW_CMD;
        atomic_set(&cmd->t_transport_active, 1);
        /*
         * transport_generic_new_cmd() is already handling QUEUE_FULL,
         * so follow TRANSPORT_NEW_CMD processing thread context usage
         * and call transport_generic_request_failure() if necessary..
         */
        ret = transport_generic_new_cmd(cmd);
        if (ret < 0)
                transport_generic_request_failure(cmd);

        return 0;
}
EXPORT_SYMBOL(transport_handle_cdb_direct);

/**
 * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
 *
 * @se_cmd: command descriptor to submit
 * @se_sess: associated se_sess for endpoint
 * @cdb: pointer to SCSI CDB
 * @sense: pointer to SCSI sense buffer
 * @unpacked_lun: unpacked LUN to reference for struct se_lun
 * @data_length: fabric expected data transfer length
 * @task_addr: SAM task attribute
 * @data_dir: DMA data direction
 * @flags: flags for command submission from target_sc_flags_tables
 *
 * This may only be called from process context, and also currently
 * assumes internal allocation of fabric payload buffer by target-core.
 **/
void target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
                unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
                u32 data_length, int task_attr, int data_dir, int flags)
{
        struct se_portal_group *se_tpg;
        int rc;

        se_tpg = se_sess->se_tpg;
        BUG_ON(!se_tpg);
        BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
        BUG_ON(in_interrupt());
        /*
         * Initialize se_cmd for target operation.  From this point
         * exceptions are handled by sending exception status via
         * target_core_fabric_ops->queue_status() callback
         */
        transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
                                data_length, data_dir, task_attr, sense);
        /*
         * Obtain struct se_cmd->cmd_kref reference and add new cmd to
         * se_sess->sess_cmd_list.  A second kref_get here is necessary
         * for fabrics using TARGET_SCF_ACK_KREF that expect a second
         * kref_put() to happen during fabric packet acknowledgement.
         */
        target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
        /*
         * Signal bidirectional data payloads to target-core
         */
        if (flags & TARGET_SCF_BIDI_OP)
                se_cmd->se_cmd_flags |= SCF_BIDI;
        /*
         * Locate se_lun pointer and attach it to struct se_cmd
         */
        if (transport_lookup_cmd_lun(se_cmd, unpacked_lun) < 0) {
                transport_send_check_condition_and_sense(se_cmd,
                                se_cmd->scsi_sense_reason, 0);
                target_put_sess_cmd(se_sess, se_cmd);
                return;
        }
        /*
         * Sanitize CDBs via transport_generic_cmd_sequencer() and
         * allocate the necessary tasks to complete the received CDB+data
         */
        rc = transport_generic_allocate_tasks(se_cmd, cdb);
        if (rc != 0) {
                transport_generic_request_failure(se_cmd);
                return;
        }
        /*
         * Dispatch se_cmd descriptor to se_lun->lun_se_dev backend
         * for immediate execution of READs, otherwise wait for
         * transport_generic_handle_data() to be called for WRITEs
         * when fabric has filled the incoming buffer.
         */
        transport_handle_cdb_direct(se_cmd);
        return;
}
EXPORT_SYMBOL(target_submit_cmd);

/*
 * Used by fabric module frontends defining a TFO->new_cmd_map() caller
 * to  queue up a newly setup se_cmd w/ TRANSPORT_NEW_CMD_MAP in order to
 * complete setup in TCM process context w/ TFO->new_cmd_map().
 */
int transport_generic_handle_cdb_map(
        struct se_cmd *cmd)
{
        if (!cmd->se_lun) {
                dump_stack();
                pr_err("cmd->se_lun is NULL\n");
                return -EINVAL;
        }

        transport_add_cmd_to_queue(cmd, TRANSPORT_NEW_CMD_MAP, false);
        return 0;
}
EXPORT_SYMBOL(transport_generic_handle_cdb_map);

/*      transport_generic_handle_data():
 *
 *
 */
int transport_generic_handle_data(
        struct se_cmd *cmd)
{
        /*
         * For the software fabric case, then we assume the nexus is being
         * failed/shutdown when signals are pending from the kthread context
         * caller, so we return a failure.  For the HW target mode case running
         * in interrupt code, the signal_pending() check is skipped.
         */
        if (!in_interrupt() && signal_pending(current))
                return -EPERM;
        /*
         * If the received CDB has aleady been ABORTED by the generic
         * target engine, we now call transport_check_aborted_status()
         * to queue any delated TASK_ABORTED status for the received CDB to the
         * fabric module as we are expecting no further incoming DATA OUT
         * sequences at this point.
         */
        if (transport_check_aborted_status(cmd, 1) != 0)
                return 0;

        transport_add_cmd_to_queue(cmd, TRANSPORT_PROCESS_WRITE, false);
        return 0;
}
EXPORT_SYMBOL(transport_generic_handle_data);

/*      transport_generic_handle_tmr():
 *
 *
 */
int transport_generic_handle_tmr(
        struct se_cmd *cmd)
{
        transport_add_cmd_to_queue(cmd, TRANSPORT_PROCESS_TMR, false);
        return 0;
}
EXPORT_SYMBOL(transport_generic_handle_tmr);

/*
 * If the task is active, request it to be stopped and sleep until it
 * has completed.
 */
bool target_stop_task(struct se_task *task, unsigned long *flags)
{
        struct se_cmd *cmd = task->task_se_cmd;
        bool was_active = false;

        if (task->task_flags & TF_ACTIVE) {
                task->task_flags |= TF_REQUEST_STOP;
                spin_unlock_irqrestore(&cmd->t_state_lock, *flags);

                pr_debug("Task %p waiting to complete\n", task);
                wait_for_completion(&task->task_stop_comp);
                pr_debug("Task %p stopped successfully\n", task);

                spin_lock_irqsave(&cmd->t_state_lock, *flags);
                atomic_dec(&cmd->t_task_cdbs_left);
                task->task_flags &= ~(TF_ACTIVE | TF_REQUEST_STOP);
                was_active = true;
        }

        return was_active;
}

static int transport_stop_tasks_for_cmd(struct se_cmd *cmd)
{
        struct se_task *task, *task_tmp;
        unsigned long flags;
        int ret = 0;

        pr_debug("ITT[0x%08x] - Stopping tasks\n",
                cmd->se_tfo->get_task_tag(cmd));

        /*
         * No tasks remain in the execution queue
         */
        spin_lock_irqsave(&cmd->t_state_lock, flags);
        list_for_each_entry_safe(task, task_tmp,
                                &cmd->t_task_list, t_list) {
                pr_debug("Processing task %p\n", task);
                /*
                 * If the struct se_task has not been sent and is not active,
                 * remove the struct se_task from the execution queue.
                 */
                if (!(task->task_flags & (TF_ACTIVE | TF_SENT))) {
                        spin_unlock_irqrestore(&cmd->t_state_lock,
                                        flags);
                        transport_remove_task_from_execute_queue(task,
                                        cmd->se_dev);

                        pr_debug("Task %p removed from execute queue\n", task);
                        spin_lock_irqsave(&cmd->t_state_lock, flags);
                        continue;
                }

                if (!target_stop_task(task, &flags)) {
                        pr_debug("Task %p - did nothing\n", task);
                        ret++;
                }
        }
        spin_unlock_irqrestore(&cmd->t_state_lock, flags);

        return ret;
}

/*
 * Handle SAM-esque emulation for generic transport request failures.
 */
static void transport_generic_request_failure(struct se_cmd *cmd)
{
        int ret = 0;

        pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
                " CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
                cmd->t_task_cdb[0]);
        pr_debug("-----[ i_state: %d t_state: %d scsi_sense_reason: %d\n",
                cmd->se_tfo->get_cmd_state(cmd),
                cmd->t_state, cmd->scsi_sense_reason);
        pr_debug("-----[ t_tasks: %d t_task_cdbs_left: %d"
                " t_task_cdbs_sent: %d t_task_cdbs_ex_left: %d --"
                " t_transport_active: %d t_transport_stop: %d"
                " t_transport_sent: %d\n", cmd->t_task_list_num,
                atomic_read(&cmd->t_task_cdbs_left),
                atomic_read(&cmd->t_task_cdbs_sent),
                atomic_read(&cmd->t_task_cdbs_ex_left),
                atomic_read(&cmd->t_transport_active),
                atomic_read(&cmd->t_transport_stop),
                atomic_read(&cmd->t_transport_sent));

        /*
         * For SAM Task Attribute emulation for failed struct se_cmd
         */
        if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
                transport_complete_task_attr(cmd);

        switch (cmd->scsi_sense_reason) {
        case TCM_NON_EXISTENT_LUN:
        case TCM_UNSUPPORTED_SCSI_OPCODE:
        case TCM_INVALID_CDB_FIELD:
        case TCM_INVALID_PARAMETER_LIST:
        case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
        case TCM_UNKNOWN_MODE_PAGE:
        case TCM_WRITE_PROTECTED:
        case TCM_CHECK_CONDITION_ABORT_CMD:
        case TCM_CHECK_CONDITION_UNIT_ATTENTION:
        case TCM_CHECK_CONDITION_NOT_READY:
                break;
        case TCM_RESERVATION_CONFLICT:
                /*
                 * No SENSE Data payload for this case, set SCSI Status
                 * and queue the response to $FABRIC_MOD.
                 *
                 * Uses linux/include/scsi/scsi.h SAM status codes defs
                 */
                cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
                /*
                 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
                 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
                 * CONFLICT STATUS.
                 *
                 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
                 */
                if (cmd->se_sess &&
                    cmd->se_dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl == 2)
                        core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
                                cmd->orig_fe_lun, 0x2C,
                                ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);

                ret = cmd->se_tfo->queue_status(cmd);
                if (ret == -EAGAIN || ret == -ENOMEM)
                        goto queue_full;
                goto check_stop;
        default:
                pr_err("Unknown transport error for CDB 0x%02x: %d\n",
                        cmd->t_task_cdb[0], cmd->scsi_sense_reason);
                cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
                break;
        }
        /*
         * If a fabric does not define a cmd->se_tfo->new_cmd_map caller,
         * make the call to transport_send_check_condition_and_sense()
         * directly.  Otherwise expect the fabric to make the call to
         * transport_send_check_condition_and_sense() after handling
         * possible unsoliticied write data payloads.
         */
        ret = transport_send_check_condition_and_sense(cmd,
                        cmd->scsi_sense_reason, 0);
        if (ret == -EAGAIN || ret == -ENOMEM)
                goto queue_full;

check_stop:
        transport_lun_remove_cmd(cmd);
        if (!transport_cmd_check_stop_to_fabric(cmd))
                ;
        return;

queue_full:
        cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
        transport_handle_queue_full(cmd, cmd->se_dev);
}

static inline u32 transport_lba_21(unsigned char *cdb)
{
        return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
}

static inline u32 transport_lba_32(unsigned char *cdb)
{
        return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
}

static inline unsigned long long transport_lba_64(unsigned char *cdb)
{
        unsigned int __v1, __v2;

        __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
        __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];

        return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
}

/*
 * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 */
static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
{
        unsigned int __v1, __v2;

        __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
        __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];

        return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
}

static void transport_set_supported_SAM_opcode(struct se_cmd *se_cmd)
{
        unsigned long flags;

        spin_lock_irqsave(&se_cmd->t_state_lock, flags);
        se_cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
        spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
}

/*
 * Called from Fabric Module context from transport_execute_tasks()
 *
 * The return of this function determins if the tasks from struct se_cmd
 * get added to the execution queue in transport_execute_tasks(),
 * or are added to the delayed or ordered lists here.
 */
static inline int transport_execute_task_attr(struct se_cmd *cmd)
{
        if (cmd->se_dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
                return 1;
        /*
         * Check for the existence of HEAD_OF_QUEUE, and if true return 1
         * to allow the passed struct se_cmd list of tasks to the front of the list.
         */
         if (cmd->sam_task_attr == MSG_HEAD_TAG) {