drivers/target/target_core_transport.c

/*******************************************************************************
 * 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/version.h>
#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 <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_device.h>
#include <target/target_core_tmr.h>
#include <target/target_core_tpg.h>
#include <target/target_core_transport.h>
#include <target/target_core_fabric_ops.h>
#include <target/target_core_configfs.h>

#include "target_core_alua.h"
#include "target_core_hba.h"
#include "target_core_pr.h"
#include "target_core_scdb.h"
#include "target_core_ua.h"

/* #define DEBUG_CDB_HANDLER */
#ifdef DEBUG_CDB_HANDLER
#define DEBUG_CDB_H(x...) printk(KERN_INFO x)
#else
#define DEBUG_CDB_H(x...)
#endif

/* #define DEBUG_CMD_MAP */
#ifdef DEBUG_CMD_MAP
#define DEBUG_CMD_M(x...) printk(KERN_INFO x)
#else
#define DEBUG_CMD_M(x...)
#endif

/* #define DEBUG_MEM_ALLOC */
#ifdef DEBUG_MEM_ALLOC
#define DEBUG_MEM(x...) printk(KERN_INFO x)
#else
#define DEBUG_MEM(x...)
#endif

/* #define DEBUG_MEM2_ALLOC */
#ifdef DEBUG_MEM2_ALLOC
#define DEBUG_MEM2(x...) printk(KERN_INFO x)
#else
#define DEBUG_MEM2(x...)
#endif

/* #define DEBUG_SG_CALC */
#ifdef DEBUG_SG_CALC
#define DEBUG_SC(x...) printk(KERN_INFO x)
#else
#define DEBUG_SC(x...)
#endif

/* #define DEBUG_SE_OBJ */
#ifdef DEBUG_SE_OBJ
#define DEBUG_SO(x...) printk(KERN_INFO x)
#else
#define DEBUG_SO(x...)
#endif

/* #define DEBUG_CMD_VOL */
#ifdef DEBUG_CMD_VOL
#define DEBUG_VOL(x...) printk(KERN_INFO x)
#else
#define DEBUG_VOL(x...)
#endif

/* #define DEBUG_CMD_STOP */
#ifdef DEBUG_CMD_STOP
#define DEBUG_CS(x...) printk(KERN_INFO x)
#else
#define DEBUG_CS(x...)
#endif

/* #define DEBUG_PASSTHROUGH */
#ifdef DEBUG_PASSTHROUGH
#define DEBUG_PT(x...) printk(KERN_INFO x)
#else
#define DEBUG_PT(x...)
#endif

/* #define DEBUG_TASK_STOP */
#ifdef DEBUG_TASK_STOP
#define DEBUG_TS(x...) printk(KERN_INFO x)
#else
#define DEBUG_TS(x...)
#endif

/* #define DEBUG_TRANSPORT_STOP */
#ifdef DEBUG_TRANSPORT_STOP
#define DEBUG_TRANSPORT_S(x...) printk(KERN_INFO x)
#else
#define DEBUG_TRANSPORT_S(x...)
#endif

/* #define DEBUG_TASK_FAILURE */
#ifdef DEBUG_TASK_FAILURE
#define DEBUG_TF(x...) printk(KERN_INFO x)
#else
#define DEBUG_TF(x...)
#endif

/* #define DEBUG_DEV_OFFLINE */
#ifdef DEBUG_DEV_OFFLINE
#define DEBUG_DO(x...) printk(KERN_INFO x)
#else
#define DEBUG_DO(x...)
#endif

/* #define DEBUG_TASK_STATE */
#ifdef DEBUG_TASK_STATE
#define DEBUG_TSTATE(x...) printk(KERN_INFO x)
#else
#define DEBUG_TSTATE(x...)
#endif

/* #define DEBUG_STATUS_THR */
#ifdef DEBUG_STATUS_THR
#define DEBUG_ST(x...) printk(KERN_INFO x)
#else
#define DEBUG_ST(x...)
#endif

/* #define DEBUG_TASK_TIMEOUT */
#ifdef DEBUG_TASK_TIMEOUT
#define DEBUG_TT(x...) printk(KERN_INFO x)
#else
#define DEBUG_TT(x...)
#endif

/* #define DEBUG_GENERIC_REQUEST_FAILURE */
#ifdef DEBUG_GENERIC_REQUEST_FAILURE
#define DEBUG_GRF(x...) printk(KERN_INFO x)
#else
#define DEBUG_GRF(x...)
#endif

/* #define DEBUG_SAM_TASK_ATTRS */
#ifdef DEBUG_SAM_TASK_ATTRS
#define DEBUG_STA(x...) printk(KERN_INFO x)
#else
#define DEBUG_STA(x...)
#endif

static int sub_api_initialized;

static struct kmem_cache *se_cmd_cache;
static struct kmem_cache *se_sess_cache;
struct kmem_cache *se_tmr_req_cache;
struct kmem_cache *se_ua_cache;
struct kmem_cache *se_mem_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;

/* Used for transport_dev_get_map_*() */
typedef int (*map_func_t)(struct se_task *, u32);

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);
static void transport_complete_task_attr(struct se_cmd *cmd);
static void transport_direct_request_timeout(struct se_cmd *cmd);
static void transport_free_dev_tasks(struct se_cmd *cmd);
static u32 transport_generic_get_cdb_count(struct se_cmd *cmd,
		unsigned long long starting_lba, u32 sectors,
		enum dma_data_direction data_direction,
		struct list_head *mem_list, int set_counts);
static int transport_generic_get_mem(struct se_cmd *cmd, u32 length,
		u32 dma_size);
static int transport_generic_remove(struct se_cmd *cmd,
		int release_to_pool, int session_reinstatement);
static int transport_get_sectors(struct se_cmd *cmd);
static int transport_map_sg_to_mem(struct se_cmd *cmd,
		struct list_head *se_mem_list, struct scatterlist *sgl,
		u32 *se_mem_cnt);
static void transport_memcpy_se_mem_read_contig(struct se_cmd *cmd,
		unsigned char *dst, struct list_head *se_mem_list);
static void transport_release_fe_cmd(struct se_cmd *cmd);
static void transport_remove_cmd_from_queue(struct se_cmd *cmd,
		struct se_queue_obj *qobj);
static int transport_set_sense_codes(struct se_cmd *cmd, u8 asc, u8 ascq);
static void transport_stop_all_task_timers(struct se_cmd *cmd);

int init_se_kmem_caches(void)
{
	se_cmd_cache = kmem_cache_create("se_cmd_cache",
			sizeof(struct se_cmd), __alignof__(struct se_cmd), 0, NULL);
	if (!(se_cmd_cache)) {
		printk(KERN_ERR "kmem_cache_create for struct se_cmd failed\n");
		goto out;
	}
	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)) {
		printk(KERN_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)) {
		printk(KERN_ERR "kmem_cache_create() for struct se_session"
				" failed\n");
		goto out;
	}
	se_ua_cache = kmem_cache_create("se_ua_cache",
			sizeof(struct se_ua), __alignof__(struct se_ua),
			0, NULL);
	if (!(se_ua_cache)) {
		printk(KERN_ERR "kmem_cache_create() for struct se_ua failed\n");
		goto out;
	}
	se_mem_cache = kmem_cache_create("se_mem_cache",
			sizeof(struct se_mem), __alignof__(struct se_mem), 0, NULL);
	if (!(se_mem_cache)) {
		printk(KERN_ERR "kmem_cache_create() for struct se_mem failed\n");
		goto out;
	}
	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)) {
		printk(KERN_ERR "kmem_cache_create() for struct t10_pr_registration"
				" failed\n");
		goto out;
	}
	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)) {
		printk(KERN_ERR "kmem_cache_create() for t10_alua_lu_gp_cache"
				" failed\n");
		goto out;
	}
	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)) {
		printk(KERN_ERR "kmem_cache_create() for t10_alua_lu_gp_mem_"
				"cache failed\n");
		goto out;
	}
	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)) {
		printk(KERN_ERR "kmem_cache_create() for t10_alua_tg_pt_gp_"
				"cache failed\n");
		goto out;
	}
	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)) {
		printk(KERN_ERR "kmem_cache_create() for t10_alua_tg_pt_gp_"
				"mem_t failed\n");
		goto out;
	}

	return 0;
out:
	if (se_cmd_cache)
		kmem_cache_destroy(se_cmd_cache);
	if (se_tmr_req_cache)
		kmem_cache_destroy(se_tmr_req_cache);
	if (se_sess_cache)
		kmem_cache_destroy(se_sess_cache);
	if (se_ua_cache)
		kmem_cache_destroy(se_ua_cache);
	if (se_mem_cache)
		kmem_cache_destroy(se_mem_cache);
	if (t10_pr_reg_cache)
		kmem_cache_destroy(t10_pr_reg_cache);
	if (t10_alua_lu_gp_cache)
		kmem_cache_destroy(t10_alua_lu_gp_cache);
	if (t10_alua_lu_gp_mem_cache)
		kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
	if (t10_alua_tg_pt_gp_cache)
		kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
	if (t10_alua_tg_pt_gp_mem_cache)
		kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
	return -ENOMEM;
}

void release_se_kmem_caches(void)
{
	kmem_cache_destroy(se_cmd_cache);
	kmem_cache_destroy(se_tmr_req_cache);
	kmem_cache_destroy(se_sess_cache);
	kmem_cache_destroy(se_ua_cache);
	kmem_cache_destroy(se_mem_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;
}

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);
}
EXPORT_SYMBOL(transport_init_queue_obj);

static int transport_subsystem_reqmods(void)
{
	int ret;

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

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

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

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

	return 0;
}

int transport_subsystem_check_init(void)
{
	int ret;

	if (sub_api_initialized)
		return 0;
	/*
	 * Request the loading of known TCM subsystem plugins..
	 */
	ret = transport_subsystem_reqmods();
	if (ret < 0)
		return ret;

	sub_api_initialized = 1;
	return 0;
}

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)) {
		printk(KERN_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);

	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);

	printk(KERN_INFO "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;

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

	spin_lock_bh(&se_tpg->session_lock);
	list_del(&se_sess->sess_list);
	se_sess->se_tpg = NULL;
	se_sess->fabric_sess_ptr = NULL;
	spin_unlock_bh(&se_tpg->session_lock);

	/*
	 * 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_bh(&se_tpg->acl_node_lock);
		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_bh(&se_tpg->acl_node_lock);

				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_bh(&se_tpg->acl_node_lock);
			}
		}
		spin_unlock_bh(&se_tpg->acl_node_lock);
	}

	transport_free_session(se_sess);

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

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

	list_for_each_entry(task, &cmd->t_task.t_task_list, t_list) {
		dev = task->se_dev;
		if (!(dev))
			continue;

		if (atomic_read(&task->task_active))
			continue;

		if (!(atomic_read(&task->task_state_active)))
			continue;

		spin_lock_irqsave(&dev->execute_task_lock, flags);
		list_del(&task->t_state_list);
		DEBUG_TSTATE("Removed ITT: 0x%08x dev: %p task[%p]\n",
			cmd->se_tfo->tfo_get_task_tag(cmd), dev, task);
		spin_unlock_irqrestore(&dev->execute_task_lock, flags);

		atomic_set(&task->task_state_active, 0);
		atomic_dec(&cmd->t_task.t_task_cdbs_ex_left);
	}
}

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

		cmd->deferred_t_state = cmd->t_state;
		cmd->t_state = TRANSPORT_DEFERRED_CMD;
		atomic_set(&cmd->t_task.t_transport_active, 0);
		if (transport_off == 2)
			transport_all_task_dev_remove_state(cmd);
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

		complete(&cmd->t_task.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_task.t_transport_stop)) {
		DEBUG_CS("%s:%d atomic_read(&cmd->t_task.t_transport_stop) =="
			" TRUE for ITT: 0x%08x\n", __func__, __LINE__,
			cmd->se_tfo->get_task_tag(cmd));

		cmd->deferred_t_state = cmd->t_state;
		cmd->t_state = TRANSPORT_DEFERRED_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_task.t_state_lock, flags);

		complete(&cmd->t_task.t_transport_stop_comp);
		return 1;
	}
	if (transport_off) {
		atomic_set(&cmd->t_task.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.
			 */
			if (cmd->se_tfo->check_stop_free != NULL) {
				spin_unlock_irqrestore(
					&cmd->t_task.t_state_lock, flags);

				cmd->se_tfo->check_stop_free(cmd);
				return 1;
			}
		}
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

		return 0;
	} else if (t_state)
		cmd->t_state = t_state;
	spin_unlock_irqrestore(&cmd->t_task.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_task.t_state_lock, flags);
	if (!(atomic_read(&cmd->t_task.transport_dev_active))) {
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		goto check_lun;
	}
	atomic_set(&cmd->t_task.transport_dev_active, 0);
	transport_all_task_dev_remove_state(cmd);
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);


check_lun:
	spin_lock_irqsave(&lun->lun_cmd_lock, flags);
	if (atomic_read(&cmd->t_task.transport_lun_active)) {
		list_del(&cmd->se_lun_node);
		atomic_set(&cmd->t_task.transport_lun_active, 0);
#if 0
		printk(KERN_INFO "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)
{
	transport_remove_cmd_from_queue(cmd, &cmd->se_dev->dev_queue_obj);
	transport_lun_remove_cmd(cmd);

	if (transport_cmd_check_stop_to_fabric(cmd))
		return;
	if (remove)
		transport_generic_remove(cmd, 0, 0);
}

void transport_cmd_finish_abort_tmr(struct se_cmd *cmd)
{
	transport_remove_cmd_from_queue(cmd, &cmd->se_dev->dev_queue_obj);

	if (transport_cmd_check_stop_to_fabric(cmd))
		return;

	transport_generic_remove(cmd, 0, 0);
}

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

	INIT_LIST_HEAD(&cmd->se_queue_node);

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

	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
	list_add_tail(&cmd->se_queue_node, &qobj->qobj_list);
	atomic_inc(&cmd->t_task.t_transport_queue_active);
	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);

	atomic_inc(&qobj->queue_cnt);
	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_dec(&cmd->t_task.t_transport_queue_active);

	list_del(&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)
{
	struct se_cmd *t;
	unsigned long flags;

	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
	if (!(atomic_read(&cmd->t_task.t_transport_queue_active))) {
		spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
		return;
	}

	list_for_each_entry(t, &qobj->qobj_list, se_queue_node)
		if (t == cmd) {
			atomic_dec(&cmd->t_task.t_transport_queue_active);
			atomic_dec(&qobj->queue_cnt);
			list_del(&cmd->se_queue_node);
			break;
		}
	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);

	if (atomic_read(&cmd->t_task.t_transport_queue_active)) {
		printk(KERN_ERR "ITT: 0x%08x t_transport_queue_active: %d\n",
			cmd->se_tfo->get_task_tag(cmd),
			atomic_read(&cmd->t_task.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.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_error_status = PYX_TRANSPORT_ILLEGAL_REQUEST;
		task->task_se_cmd->transport_error_status =
					PYX_TRANSPORT_ILLEGAL_REQUEST;
	}

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

/*	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 = task->se_dev;
	int t_state;
	unsigned long flags;
#if 0
	printk(KERN_INFO "task: %p CDB: 0x%02x obj_ptr: %p\n", task,
			cmd->t_task.t_task_cdb[0], dev);
#endif
	if (dev)
		atomic_inc(&dev->depth_left);

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	atomic_set(&task->task_active, 0);

	/*
	 * 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_sense = 1;
			success = 1;
		}
	}

	/*
	 * See if we are waiting for outstanding struct se_task
	 * to complete for an exception condition
	 */
	if (atomic_read(&task->task_stop)) {
		/*
		 * Decrement cmd->t_task.t_se_count if this task had
		 * previously thrown its timeout exception handler.
		 */
		if (atomic_read(&task->task_timeout)) {
			atomic_dec(&cmd->t_task.t_se_count);
			atomic_set(&task->task_timeout, 0);
		}
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

		complete(&task->task_stop_comp);
		return;
	}
	/*
	 * If the task's timeout handler has fired, use the t_task_cdbs_timeout
	 * left counter to determine when the struct se_cmd is ready to be queued to
	 * the processing thread.
	 */
	if (atomic_read(&task->task_timeout)) {
		if (!(atomic_dec_and_test(
				&cmd->t_task.t_task_cdbs_timeout_left))) {
			spin_unlock_irqrestore(&cmd->t_task.t_state_lock,
				flags);
			return;
		}
		t_state = TRANSPORT_COMPLETE_TIMEOUT;
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

		transport_add_cmd_to_queue(cmd, t_state);
		return;
	}
	atomic_dec(&cmd->t_task.t_task_cdbs_timeout_left);

	/*
	 * 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.t_task_cdbs_left))) {
		if (!success)
			cmd->t_task.t_tasks_failed = 1;

		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		return;
	}

	if (!success || cmd->t_task.t_tasks_failed) {
		t_state = TRANSPORT_COMPLETE_FAILURE;
		if (!task->task_error_status) {
			task->task_error_status =
				PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
			cmd->transport_error_status =
				PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
		}
	} else {
		atomic_set(&cmd->t_task.t_transport_complete, 1);
		t_state = TRANSPORT_COMPLETE_OK;
	}
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

	transport_add_cmd_to_queue(cmd, t_state);
}
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);

		DEBUG_STA("Set HEAD_OF_QUEUE for task CDB: 0x%02x"
				" in execution queue\n",
				T_TASK(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 (atomic_read(&task->task_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);

	atomic_set(&task->task_state_active, 1);

	DEBUG_TSTATE("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;
	struct se_task *task;
	unsigned long flags;

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	list_for_each_entry(task, &cmd->t_task.t_task_list, t_list) {
		dev = task->se_dev;

		if (atomic_read(&task->task_state_active))
			continue;

		spin_lock(&dev->execute_task_lock);
		list_add_tail(&task->t_state_list, &dev->state_task_list);
		atomic_set(&task->task_state_active, 1);

		DEBUG_TSTATE("Added ITT: 0x%08x task[%p] to dev: %p\n",
			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_task.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;
	unsigned long flags;

	spin_lock_irqsave(&dev->execute_task_lock, flags);
	list_for_each_entry(task, &cmd->t_task.t_task_list, t_list) {
		if (atomic_read(&task->task_execute_queue))
			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);
		atomic_set(&task->task_execute_queue, 1);
		task_prev = task;
	}
	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}

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

	if (atomic_read(&task->task_execute_queue) == 0) {
		dump_stack();
		return;
	}

	spin_lock_irqsave(&dev->execute_task_lock, flags);
	list_del(&task->t_execute_list);
	atomic_set(&task->task_execute_queue, 0);
	atomic_dec(&dev->execute_tasks);
	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
}

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/Left/Max Queue Depth: %d/%d/%d",
		atomic_read(&dev->execute_tasks), atomic_read(&dev->depth_left),
		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, "        ");
}

/*	transport_release_all_cmds():
 *
 *
 */
static void transport_release_all_cmds(struct se_device *dev)
{
	struct se_cmd *cmd, *tcmd;
	int bug_out = 0, t_state;
	unsigned long flags;

	spin_lock_irqsave(&dev->dev_queue_obj.cmd_queue_lock, flags);
	list_for_each_entry_safe(cmd, tcmd, &dev->dev_queue_obj.qobj_list,
				se_queue_node) {
		t_state = cmd->t_state;
		list_del(&cmd->se_queue_node);
		spin_unlock_irqrestore(&dev->dev_queue_obj.cmd_queue_lock,
				flags);

		printk(KERN_ERR "Releasing ITT: 0x%08x, i_state: %u,"
			" t_state: %u directly\n",
			cmd->se_tfo->get_task_tag(cmd),
			cmd->se_tfo->get_cmd_state(cmd), t_state);

		transport_release_fe_cmd(cmd);
		bug_out = 1;

		spin_lock_irqsave(&dev->dev_queue_obj.cmd_queue_lock, flags);
	}
	spin_unlock_irqrestore(&dev->dev_queue_obj.cmd_queue_lock, flags);
#if 0
	if (bug_out)
		BUG();
#endif
}

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
		printk(KERN_INFO "%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
		printk("%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 {
		printk("%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
		printk("%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;
	DEBUG_STA("%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;
	int i, device_type;
	/*
	 * Print Linux/SCSI style INQUIRY formatting to the kernel ring buffer
	 */
	printk("  Vendor: ");
	for (i = 0; i < 8; i++)
		if (wwn->vendor[i] >= 0x20)
			printk("%c", wwn->vendor[i]);
		else
			printk(" ");

	printk("  Model: ");
	for (i = 0; i < 16; i++)
		if (wwn->model[i] >= 0x20)
			printk("%c", wwn->model[i]);
		else
			printk(" ");

	printk("  Revision: ");
	for (i = 0; i < 4; i++)
		if (wwn->revision[i] >= 0x20)
			printk("%c", wwn->revision[i]);
		else
			printk(" ");

	printk("\n");

	device_type = dev->transport->get_device_type(dev);
	printk("  Type:   %s ", scsi_device_type(device_type));
	printk("                 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)) {
		printk(KERN_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;
	atomic_set(&dev->active_cmds, 0);
	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->ordered_cmd_list);
	INIT_LIST_HEAD(&dev->state_task_list);
	spin_lock_init(&dev->execute_task_lock);
	spin_lock_init(&dev->delayed_cmd_lock);
	spin_lock_init(&dev->ordered_cmd_lock);
	spin_lock_init(&dev->state_task_lock);
	spin_lock_init(&dev->dev_alua_lock);
	spin_lock_init(&dev->dev_reservation_lock);
	spin_lock_init(&dev->dev_status_lock);
	spin_lock_init(&dev->dev_status_thr_lock);
	spin_lock_init(&dev->se_port_lock);
	spin_lock_init(&dev->se_tmr_lock);

	dev->queue_depth	= dev_limits->queue_depth;
	atomic_set(&dev->depth_left, dev->queue_depth);
	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)) {
		printk(KERN_ERR "Unable to create kthread: LIO_%s\n",
			dev->transport->name);
		goto out;
	}

	/*
	 * 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) {
			printk(KERN_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;
	unsigned long flags;

	task = dev->transport->alloc_task(cmd);
	if (!task) {
		printk(KERN_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_no = cmd->t_task.t_tasks_no++;
	task->task_se_cmd = cmd;
	task->se_dev = dev;
	task->task_data_direction = data_direction;

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	list_add_tail(&task->t_list, &cmd->t_task.t_task_list);
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

	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_ordered_node);

	INIT_LIST_HEAD(&cmd->t_task.t_mem_list);
	INIT_LIST_HEAD(&cmd->t_task.t_mem_bidi_list);
	INIT_LIST_HEAD(&cmd->t_task.t_task_list);
	init_completion(&cmd->t_task.transport_lun_fe_stop_comp);
	init_completion(&cmd->t_task.transport_lun_stop_comp);
	init_completion(&cmd->t_task.t_transport_stop_comp);
	spin_lock_init(&cmd->t_task.t_state_lock);
	atomic_set(&cmd->t_task.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) {
		DEBUG_STA("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();
	DEBUG_STA("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
			cmd->se_ordered_id, cmd->sam_task_attr,
			TRANSPORT(cmd->se_dev)->name);
	return 0;
}

void transport_free_se_cmd(
	struct se_cmd *se_cmd)
{
	if (se_cmd->se_tmr_req)
		core_tmr_release_req(se_cmd->se_tmr_req);
	/*
	 * Check and free any extended CDB buffer that was allocated
	 */
	if (se_cmd->t_task.t_task_cdb != se_cmd->t_task.__t_task_cdb)
		kfree(se_cmd->t_task.t_task_cdb);
}
EXPORT_SYMBOL(transport_free_se_cmd);

static void transport_generic_wait_for_tasks(struct se_cmd *, int, int);

/*	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);

	/*
	 * This is needed for early exceptions.
	 */
	cmd->transport_wait_for_tasks = &transport_generic_wait_for_tasks;

	/*
	 * 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) {
		printk(KERN_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);
		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.__t_task_cdb)) {
		cmd->t_task.t_task_cdb = kzalloc(scsi_command_size(cdb),
						GFP_KERNEL);
		if (!(cmd->t_task.t_task_cdb)) {
			printk(KERN_ERR "Unable to allocate cmd->t_task.t_task_cdb"
				" %u > sizeof(cmd->t_task.__t_task_cdb): %lu ops\n",
				scsi_command_size(cdb),
				(unsigned long)sizeof(cmd->t_task.__t_task_cdb));
			return -ENOMEM;
		}
	} else
		cmd->t_task.t_task_cdb = &cmd->t_task.__t_task_cdb[0];
	/*
	 * Copy the original CDB into cmd->t_task.
	 */
	memcpy(cmd->t_task.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.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 not defining a TFO->new_cmd_map()
 * to queue up a newly setup se_cmd w/ TRANSPORT_NEW_CMD statis
 */
int transport_generic_handle_cdb(
	struct se_cmd *cmd)
{
	if (!cmd->se_lun) {
		dump_stack();
		printk(KERN_ERR "cmd->se_lun is NULL\n");
		return -EINVAL;
	}

	transport_add_cmd_to_queue(cmd, TRANSPORT_NEW_CMD);
	return 0;
}
EXPORT_SYMBOL(transport_generic_handle_cdb);

/*
 * 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();
		printk(KERN_ERR "cmd->se_lun is NULL\n");
		return -EINVAL;
	}

	transport_add_cmd_to_queue(cmd, TRANSPORT_NEW_CMD_MAP);
	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);
	return 0;
}
EXPORT_SYMBOL(transport_generic_handle_data);

/*	transport_generic_handle_tmr():
 *
 *
 */
int transport_generic_handle_tmr(
	struct se_cmd *cmd)
{
	/*
	 * This is needed for early exceptions.
	 */
	cmd->transport_wait_for_tasks = &transport_generic_wait_for_tasks;

	transport_add_cmd_to_queue(cmd, TRANSPORT_PROCESS_TMR);
	return 0;
}
EXPORT_SYMBOL(transport_generic_handle_tmr);

void transport_generic_free_cmd_intr(
	struct se_cmd *cmd)
{
	transport_add_cmd_to_queue(cmd, TRANSPORT_FREE_CMD_INTR);
}
EXPORT_SYMBOL(transport_generic_free_cmd_intr);

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

	DEBUG_TS("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_task.t_state_lock, flags);
	list_for_each_entry_safe(task, task_tmp,
				&cmd->t_task.t_task_list, t_list) {
		DEBUG_TS("task_no[%d] - Processing task %p\n",
				task->task_no, task);
		/*
		 * If the struct se_task has not been sent and is not active,
		 * remove the struct se_task from the execution queue.
		 */
		if (!atomic_read(&task->task_sent) &&
		    !atomic_read(&task->task_active)) {
			spin_unlock_irqrestore(&cmd->t_task.t_state_lock,
					flags);
			transport_remove_task_from_execute_queue(task,
					task->se_dev);

			DEBUG_TS("task_no[%d] - Removed from execute queue\n",
				task->task_no);
			spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
			continue;
		}

		/*
		 * If the struct se_task is active, sleep until it is returned
		 * from the plugin.
		 */
		if (atomic_read(&task->task_active)) {
			atomic_set(&task->task_stop, 1);
			spin_unlock_irqrestore(&cmd->t_task.t_state_lock,
					flags);

			DEBUG_TS("task_no[%d] - Waiting to complete\n",
				task->task_no);
			wait_for_completion(&task->task_stop_comp);
			DEBUG_TS("task_no[%d] - Stopped successfully\n",
				task->task_no);

			spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
			atomic_dec(&cmd->t_task.t_task_cdbs_left);

			atomic_set(&task->task_active, 0);
			atomic_set(&task->task_stop, 0);
		} else {
			DEBUG_TS("task_no[%d] - Did nothing\n", task->task_no);
			ret++;
		}

		__transport_stop_task_timer(task, &flags);
	}
	spin_unlock_irqrestore(&cmd->t_task.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,
	struct se_device *dev,
	int complete,
	int sc)
{
	DEBUG_GRF("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
		cmd->t_task.t_task_cdb[0]);
	DEBUG_GRF("-----[ i_state: %d t_state/def_t_state:"
		" %d/%d transport_error_status: %d\n",
		cmd->se_tfo->get_cmd_state(cmd),
		cmd->t_state, cmd->deferred_t_state,
		cmd->transport_error_status);
	DEBUG_GRF("-----[ t_task_cdbs: %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.t_task_cdbs,
		atomic_read(&cmd->t_task.t_task_cdbs_left),
		atomic_read(&cmd->t_task.t_task_cdbs_sent),
		atomic_read(&cmd->t_task.t_task_cdbs_ex_left),
		atomic_read(&cmd->t_task.t_transport_active),
		atomic_read(&cmd->t_task.t_transport_stop),
		atomic_read(&cmd->t_task.t_transport_sent));

	transport_stop_all_task_timers(cmd);

	if (dev)
		atomic_inc(&dev->depth_left);
	/*
	 * 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);

	if (complete) {
		transport_direct_request_timeout(cmd);
		cmd->transport_error_status = PYX_TRANSPORT_LU_COMM_FAILURE;
	}

	switch (cmd->transport_error_status) {
	case PYX_TRANSPORT_UNKNOWN_SAM_OPCODE:
		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
		break;
	case PYX_TRANSPORT_REQ_TOO_MANY_SECTORS:
		cmd->scsi_sense_reason = TCM_SECTOR_COUNT_TOO_MANY;
		break;
	case PYX_TRANSPORT_INVALID_CDB_FIELD:
		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
		break;
	case PYX_TRANSPORT_INVALID_PARAMETER_LIST:
		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
		break;
	case PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES:
		if (!sc)
			transport_new_cmd_failure(cmd);
		/*
		 * Currently for PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES,
		 * we force this session to fall back to session
		 * recovery.
		 */
		cmd->se_tfo->fall_back_to_erl0(cmd->se_sess);
		cmd->se_tfo->stop_session(cmd->se_sess, 0, 0);

		goto check_stop;
	case PYX_TRANSPORT_LU_COMM_FAILURE:
	case PYX_TRANSPORT_ILLEGAL_REQUEST:
		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		break;
	case PYX_TRANSPORT_UNKNOWN_MODE_PAGE:
		cmd->scsi_sense_reason = TCM_UNKNOWN_MODE_PAGE;
		break;
	case PYX_TRANSPORT_WRITE_PROTECTED:
		cmd->scsi_sense_reason = TCM_WRITE_PROTECTED;
		break;
	case PYX_TRANSPORT_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);

		cmd->se_tfo->queue_status(cmd);
		goto check_stop;
	case PYX_TRANSPORT_USE_SENSE_REASON:
		/*
		 * struct se_cmd->scsi_sense_reason already set
		 */
		break;
	default:
		printk(KERN_ERR "Unknown transport error for CDB 0x%02x: %d\n",
			cmd->t_task.t_task_cdb[0],
			cmd->transport_error_status);
		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
		break;
	}

	if (!sc)
		transport_new_cmd_failure(cmd);
	else
		transport_send_check_condition_and_sense(cmd,
			cmd->scsi_sense_reason, 0);
check_stop:
	transport_lun_remove_cmd(cmd);
	if (!(transport_cmd_check_stop_to_fabric(cmd)))
		;
}

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

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	if (!(atomic_read(&cmd->t_task.t_transport_timeout))) {
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		return;
	}
	if (atomic_read(&cmd->t_task.t_task_cdbs_timeout_left)) {
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		return;
	}

	atomic_sub(atomic_read(&cmd->t_task.t_transport_timeout),
		   &cmd->t_task.t_se_count);
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
}

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

	/*
	 * Reset cmd->t_task.t_se_count to allow transport_generic_remove()
	 * to allow last call to free memory resources.
	 */
	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	if (atomic_read(&cmd->t_task.t_transport_timeout) > 1) {
		int tmp = (atomic_read(&cmd->t_task.t_transport_timeout) - 1);

		atomic_sub(tmp, &cmd->t_task.t_se_count);
	}
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

	transport_generic_remove(cmd, 0, 0);
}

static int
transport_generic_allocate_buf(struct se_cmd *cmd, u32 data_length)
{
	unsigned char *buf;

	buf = kzalloc(data_length, GFP_KERNEL);
	if (!(buf)) {
		printk(KERN_ERR "Unable to allocate memory for buffer\n");
		return -ENOMEM;
	}

	cmd->t_task.t_tasks_se_num = 0;
	cmd->t_task.t_task_buf = buf;

	return 0;
}

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

/*
 * Called from interrupt context.
 */
static void transport_task_timeout_handler(unsigned long data)
{
	struct se_task *task = (struct se_task *)data;
	struct se_cmd *cmd = task->task_se_cmd;
	unsigned long flags;

	DEBUG_TT("transport task timeout fired! task: %p cmd: %p\n", task, cmd);

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	if (task->task_flags & TF_STOP) {
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		return;
	}
	task->task_flags &= ~TF_RUNNING;

	/*
	 * Determine if transport_complete_task() has already been called.
	 */
	if (!(atomic_read(&task->task_active))) {
		DEBUG_TT("transport task: %p cmd: %p timeout task_active"
				" == 0\n", task, cmd);
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		return;
	}

	atomic_inc(&cmd->t_task.t_se_count);
	atomic_inc(&cmd->t_task.t_transport_timeout);
	cmd->t_task.t_tasks_failed = 1;

	atomic_set(&task->task_timeout, 1);
	task->task_error_status = PYX_TRANSPORT_TASK_TIMEOUT;
	task->task_scsi_status = 1;

	if (atomic_read(&task->task_stop)) {
		DEBUG_TT("transport task: %p cmd: %p timeout task_stop"
				" == 1\n", task, cmd);
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		complete(&task->task_stop_comp);
		return;
	}

	if (!(atomic_dec_and_test(&cmd->t_task.t_task_cdbs_left))) {
		DEBUG_TT("transport task: %p cmd: %p timeout non zero"
				" t_task_cdbs_left\n", task, cmd);
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		return;
	}
	DEBUG_TT("transport task: %p cmd: %p timeout ZERO t_task_cdbs_left\n",
			task, cmd);

	cmd->t_state = TRANSPORT_COMPLETE_FAILURE;
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

	transport_add_cmd_to_queue(cmd, TRANSPORT_COMPLETE_FAILURE);
}

/*
 * Called with cmd->t_task.t_state_lock held.
 */
static void transport_start_task_timer(struct se_task *task)
{
	struct se_device *dev = task->se_dev;
	int timeout;

	if (task->task_flags & TF_RUNNING)
		return;
	/*
	 * If the task_timeout is disabled, exit now.
	 */
	timeout = dev->se_sub_dev->se_dev_attrib.task_timeout;
	if (!(timeout))
		return;

	init_timer(&task->task_timer);
	task->task_timer.expires = (get_jiffies_64() + timeout * HZ);
	task->task_timer.data = (unsigned long) task;
	task->task_timer.function = transport_task_timeout_handler;

	task->task_flags |= TF_RUNNING;
	add_timer(&task->task_timer);
#if 0
	printk(KERN_INFO "Starting task timer for cmd: %p task: %p seconds:"
		" %d\n", task->task_se_cmd, task, timeout);
#endif
}

/*
 * Called with spin_lock_irq(&cmd->t_task.t_state_lock) held.
 */
void __transport_stop_task_timer(struct se_task *task, unsigned long *flags)
{
	struct se_cmd *cmd = task->task_se_cmd;

	if (!(task->task_flags & TF_RUNNING))
		return;

	task->task_flags |= TF_STOP;
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, *flags);

	del_timer_sync(&task->task_timer);

	spin_lock_irqsave(&cmd->t_task.t_state_lock, *flags);
	task->task_flags &= ~TF_RUNNING;
	task->task_flags &= ~TF_STOP;
}

static void transport_stop_all_task_timers(struct se_cmd *cmd)
{
	struct se_task *task = NULL, *task_tmp;
	unsigned long flags;

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	list_for_each_entry_safe(task, task_tmp,
				&cmd->t_task.t_task_list, t_list)
		__transport_stop_task_timer(task, &flags);
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
}

static inline int transport_tcq_window_closed(struct se_device *dev)
{
	if (dev->dev_tcq_window_closed++ <
			PYX_TRANSPORT_WINDOW_CLOSED_THRESHOLD) {
		msleep(PYX_TRANSPORT_WINDOW_CLOSED_WAIT_SHORT);
	} else
		msleep(PYX_TRANSPORT_WINDOW_CLOSED_WAIT_LONG);

	wake_up_interruptible(&dev->dev_queue_obj.thread_wq);
	return 0;
}

/*
 * 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) {
		atomic_inc(&cmd->se_dev->dev_hoq_count);
		smp_mb__after_atomic_inc();
		DEBUG_STA("Added HEAD_OF_QUEUE for CDB:"
			" 0x%02x, se_ordered_id: %u\n",
			cmd->t_task->t_task_cdb[0],
			cmd->se_ordered_id);
		return 1;
	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
		spin_lock(&cmd->se_dev->ordered_cmd_lock);
		list_add_tail(&cmd->se_ordered_node,
				&cmd->se_dev->ordered_cmd_list);
		spin_unlock(&cmd->se_dev->ordered_cmd_lock);

		atomic_inc(&cmd->se_dev->dev_ordered_sync);
		smp_mb__after_atomic_inc();

		DEBUG_STA("Added ORDERED for CDB: 0x%02x to ordered"
				" list, se_ordered_id: %u\n",
				cmd->t_task.t_task_cdb[0],
				cmd->se_ordered_id);
		/*
		 * Add ORDERED command to tail of execution queue if
		 * no other older commands exist that need to be
		 * completed first.
		 */
		if (!(atomic_read(&cmd->se_dev->simple_cmds)))
			return 1;
	} else {
		/*
		 * For SIMPLE and UNTAGGED Task Attribute commands
		 */
		atomic_inc(&cmd->se_dev->simple_cmds);
		smp_mb__after_atomic_inc();
	}
	/*
	 * Otherwise if one or more outstanding ORDERED task attribute exist,
	 * add the dormant task(s) built for the passed struct se_cmd to the
	 * execution queue and become in Active state for this struct se_device.
	 */
	if (atomic_read(&cmd->se_dev->dev_ordered_sync) != 0) {
		/*
		 * Otherwise, add cmd w/ tasks to delayed cmd queue that
		 * will be drained upon completion of HEAD_OF_QUEUE task.
		 */
		spin_lock(&cmd->se_dev->delayed_cmd_lock);
		cmd->se_cmd_flags |= SCF_DELAYED_CMD_FROM_SAM_ATTR;
		list_add_tail(&cmd->se_delayed_node,
				&cmd->se_dev->delayed_cmd_list);
		spin_unlock(&cmd->se_dev->delayed_cmd_lock);

		DEBUG_STA("Added CDB: 0x%02x Task Attr: 0x%02x to"
			" delayed CMD list, se_ordered_id: %u\n",
			cmd->t_task.t_task_cdb[0], cmd->sam_task_attr,
			cmd->se_ordered_id);
		/*
		 * Return zero to let transport_execute_tasks() know
		 * not to add the delayed tasks to the execution list.
		 */
		return 0;
	}
	/*
	 * Otherwise, no ORDERED task attributes exist..
	 */
	return 1;
}

/*
 * Called from fabric module context in transport_generic_new_cmd() and
 * transport_generic_process_write()
 */
static int transport_execute_tasks(struct se_cmd *cmd)
{
	int add_tasks;

	if (!(cmd->se_cmd_flags & SCF_SE_DISABLE_ONLINE_CHECK)) {
		if (se_dev_check_online(cmd->se_orig_obj_ptr) != 0) {
			cmd->transport_error_status =
				PYX_TRANSPORT_LU_COMM_FAILURE;
			transport_generic_request_failure(cmd, NULL, 0, 1);
			return 0;
		}
	}
	/*
	 * Call transport_cmd_check_stop() to see if a fabric exception
	 * has occurred that prevents execution.
	 */
	if (!(transport_cmd_check_stop(cmd, 0, TRANSPORT_PROCESSING))) {
		/*
		 * Check for SAM Task Attribute emulation and HEAD_OF_QUEUE
		 * attribute for the tasks of the received struct se_cmd CDB
		 */
		add_tasks = transport_execute_task_attr(cmd);
		if (!add_tasks)
			goto execute_tasks;
		/*
		 * This calls transport_add_tasks_from_cmd() to handle
		 * HEAD_OF_QUEUE ordering for SAM Task Attribute emulation
		 * (if enabled) in __transport_add_task_to_execute_queue() and
		 * transport_add_task_check_sam_attr().
		 */
		transport_add_tasks_from_cmd(cmd);
	}
	/*
	 * Kick the execution queue for the cmd associated struct se_device
	 * storage object.
	 */
execute_tasks:
	__transport_execute_tasks(cmd->se_dev);
	return 0;
}

/*
 * Called to check struct se_device tcq depth window, and once open pull struct se_task
 * from struct se_device->execute_task_list and
 *
 * Called from transport_processing_thread()
 */
static int __transport_execute_tasks(struct se_device *dev)
{
	int error;
	struct se_cmd *cmd = NULL;
	struct se_task *task = NULL;
	unsigned long flags;

	/*
	 * Check if there is enough room in the device and HBA queue to send
	 * struct se_transport_task's to the selected transport.
	 */
check_depth:
	if (!atomic_read(&dev->depth_left))
		return transport_tcq_window_closed(dev);

	dev->dev_tcq_window_closed = 0;

	spin_lock_irq(&dev->execute_task_lock);
	if (list_empty(&dev->execute_task_list)) {
		spin_unlock_irq(&dev->execute_task_lock);
		return 0;
	}
	task = list_first_entry(&dev->execute_task_list,
				struct se_task, t_execute_list);
	list_del(&task->t_execute_list);
	atomic_set(&task->task_execute_queue, 0);
	atomic_dec(&dev->execute_tasks);
	spin_unlock_irq(&dev->execute_task_lock);

	atomic_dec(&dev->depth_left);

	cmd = task->task_se_cmd;

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	atomic_set(&task->task_active, 1);
	atomic_set(&task->task_sent, 1);
	atomic_inc(&cmd->t_task.t_task_cdbs_sent);

	if (atomic_read(&cmd->t_task.t_task_cdbs_sent) ==
	    cmd->t_task.t_task_cdbs)
		atomic_set(&cmd->transport_sent, 1);

	transport_start_task_timer(task);
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
	/*
	 * The struct se_cmd->transport_emulate_cdb() function pointer is used
	 * to grab REPORT_LUNS and other CDBs we want to handle before they hit the
	 * struct se_subsystem_api->do_task() caller below.
	 */
	if (cmd->transport_emulate_cdb) {
		error = cmd->transport_emulate_cdb(cmd);
		if (error != 0) {
			cmd->transport_error_status = error;
			atomic_set(&task->task_active, 0);
			atomic_set(&cmd->transport_sent, 0);
			transport_stop_tasks_for_cmd(cmd);
			transport_generic_request_failure(cmd, dev, 0, 1);
			goto check_depth;
		}
		/*
		 * Handle the successful completion for transport_emulate_cdb()
		 * for synchronous operation, following SCF_EMULATE_CDB_ASYNC
		 * Otherwise the caller is expected to complete the task with
		 * proper status.
		 */
		if (!(cmd->se_cmd_flags & SCF_EMULATE_CDB_ASYNC)) {
			cmd->scsi_status = SAM_STAT_GOOD;
			task->task_scsi_status = GOOD;
			transport_complete_task(task, 1);
		}
	} else {
		/*
		 * Currently for all virtual TCM plugins including IBLOCK, FILEIO and
		 * RAMDISK we use the internal transport_emulate_control_cdb() logic
		 * with struct se_subsystem_api callers for the primary SPC-3 TYPE_DISK
		 * LUN emulation code.
		 *
		 * For TCM/pSCSI and all other SCF_SCSI_DATA_SG_IO_CDB I/O tasks we
		 * call ->do_task() directly and let the underlying TCM subsystem plugin
		 * code handle the CDB emulation.
		 */
		if ((dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV) &&
		    (!(task->task_se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB)))
			error = transport_emulate_control_cdb(task);
		else
			error = dev->transport->do_task(task);

		if (error != 0) {
			cmd->transport_error_status = error;
			atomic_set(&task->task_active, 0);
			atomic_set(&cmd->transport_sent, 0);
			transport_stop_tasks_for_cmd(cmd);
			transport_generic_request_failure(cmd, dev, 0, 1);
		}
	}

	goto check_depth;

	return 0;
}

void transport_new_cmd_failure(struct se_cmd *se_cmd)
{
	unsigned long flags;
	/*
	 * Any unsolicited data will get dumped for failed command inside of
	 * the fabric plugin
	 */
	spin_lock_irqsave(&se_cmd->t_task.t_state_lock, flags);
	se_cmd->se_cmd_flags |= SCF_SE_CMD_FAILED;
	se_cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
	spin_unlock_irqrestore(&se_cmd->t_task.t_state_lock, flags);

	se_cmd->se_tfo->new_cmd_failure(se_cmd);
}

static void transport_nop_wait_for_tasks(struct se_cmd *, int, int);

static inline u32 transport_get_sectors_6(
	unsigned char *cdb,
	struct se_cmd *cmd,
	int *ret)
{
	struct se_device *dev = cmd->se_dev;

	/*
	 * Assume TYPE_DISK for non struct se_device objects.
	 * Use 8-bit sector value.
	 */
	if (!dev)
		goto type_disk;

	/*
	 * Use 24-bit allocation length for TYPE_TAPE.
	 */
	if (dev->transport->get_device_type(dev) == TYPE_TAPE)
		return (u32)(cdb[2] << 16) + (cdb[3] << 8) + cdb[4];

	/*
	 * Everything else assume TYPE_DISK Sector CDB location.
	 * Use 8-bit sector value.
	 */
type_disk:
	return (u32)cdb[4];
}

static inline u32 transport_get_sectors_10(
	unsigned char *cdb,
	struct se_cmd *cmd,
	int *ret)
{
	struct se_device *dev = cmd->se_dev;

	/*
	 * Assume TYPE_DISK for non struct se_device objects.
	 * Use 16-bit sector value.
	 */
	if (!dev)
		goto type_disk;

	/*
	 * XXX_10 is not defined in SSC, throw an exception
	 */
	if (dev->transport->get_device_type(dev) == TYPE_TAPE) {
		*ret = -EINVAL;
		return 0;
	}

	/*
	 * Everything else assume TYPE_DISK Sector CDB location.
	 * Use 16-bit sector value.
	 */
type_disk:
	return (u32)(cdb[7] << 8) + cdb[8];
}

static inline u32 transport_get_sectors_12(
	unsigned char *cdb,
	struct se_cmd *cmd,
	int *ret)
{
	struct se_device *dev = cmd->se_dev;

	/*
	 * Assume TYPE_DISK for non struct se_device objects.
	 * Use 32-bit sector value.
	 */
	if (!dev)
		goto type_disk;

	/*
	 * XXX_12 is not defined in SSC, throw an exception
	 */
	if (dev->transport->get_device_type(dev) == TYPE_TAPE) {
		*ret = -EINVAL;
		return 0;
	}

	/*
	 * Everything else assume TYPE_DISK Sector CDB location.
	 * Use 32-bit sector value.
	 */
type_disk:
	return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
}

static inline u32 transport_get_sectors_16(
	unsigned char *cdb,
	struct se_cmd *cmd,
	int *ret)
{
	struct se_device *dev = cmd->se_dev;

	/*
	 * Assume TYPE_DISK for non struct se_device objects.
	 * Use 32-bit sector value.
	 */
	if (!dev)
		goto type_disk;

	/*
	 * Use 24-bit allocation length for TYPE_TAPE.
	 */
	if (dev->transport->get_device_type(dev) == TYPE_TAPE)
		return (u32)(cdb[12] << 16) + (cdb[13] << 8) + cdb[14];

type_disk:
	return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
		    (cdb[12] << 8) + cdb[13];
}

/*
 * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 */
static inline u32 transport_get_sectors_32(
	unsigned char *cdb,
	struct se_cmd *cmd,
	int *ret)
{
	/*
	 * Assume TYPE_DISK for non struct se_device objects.
	 * Use 32-bit sector value.
	 */
	return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
		    (cdb[30] << 8) + cdb[31];

}

static inline u32 transport_get_size(
	u32 sectors,
	unsigned char *cdb,
	struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;

	if (dev->transport->get_device_type(dev) == TYPE_TAPE) {
		if (cdb[1] & 1) { /* sectors */
			return dev->se_sub_dev->se_dev_attrib.block_size * sectors;
		} else /* bytes */
			return sectors;
	}
#if 0
	printk(KERN_INFO "Returning block_size: %u, sectors: %u == %u for"
			" %s object\n", dev->se_sub_dev->se_dev_attrib.block_size, sectors,
			dev->se_sub_dev->se_dev_attrib.block_size * sectors,
			dev->transport->name);
#endif
	return dev->se_sub_dev->se_dev_attrib.block_size * sectors;
}

unsigned char transport_asciihex_to_binaryhex(unsigned char val[2])
{
	unsigned char result = 0;
	/*
	 * MSB
	 */
	if ((val[0] >= 'a') && (val[0] <= 'f'))
		result = ((val[0] - 'a' + 10) & 0xf) << 4;
	else
		if ((val[0] >= 'A') && (val[0] <= 'F'))
			result = ((val[0] - 'A' + 10) & 0xf) << 4;
		else /* digit */
			result = ((val[0] - '0') & 0xf) << 4;
	/*
	 * LSB
	 */
	if ((val[1] >= 'a') && (val[1] <= 'f'))
		result |= ((val[1] - 'a' + 10) & 0xf);
	else
		if ((val[1] >= 'A') && (val[1] <= 'F'))
			result |= ((val[1] - 'A' + 10) & 0xf);
		else /* digit */
			result |= ((val[1] - '0') & 0xf);

	return result;
}
EXPORT_SYMBOL(transport_asciihex_to_binaryhex);

static void transport_xor_callback(struct se_cmd *cmd)
{
	unsigned char *buf, *addr;
	struct se_mem *se_mem;
	unsigned int offset;
	int i;
	/*
	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
	 *
	 * 1) read the specified logical block(s);
	 * 2) transfer logical blocks from the data-out buffer;
	 * 3) XOR the logical blocks transferred from the data-out buffer with
	 *    the logical blocks read, storing the resulting XOR data in a buffer;
	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
	 *    blocks transferred from the data-out buffer; and
	 * 5) transfer the resulting XOR data to the data-in buffer.
	 */
	buf = kmalloc(cmd->data_length, GFP_KERNEL);
	if (!(buf)) {
		printk(KERN_ERR "Unable to allocate xor_callback buf\n");
		return;
	}
	/*
	 * Copy the scatterlist WRITE buffer located at cmd->t_task.t_mem_list
	 * into the locally allocated *buf
	 */
	transport_memcpy_se_mem_read_contig(cmd, buf, &cmd->t_task.t_mem_list);
	/*
	 * Now perform the XOR against the BIDI read memory located at
	 * cmd->t_task.t_mem_bidi_list
	 */

	offset = 0;
	list_for_each_entry(se_mem, &cmd->t_task.t_mem_bidi_list, se_list) {
		addr = (unsigned char *)kmap_atomic(se_mem->se_page, KM_USER0);
		if (!(addr))
			goto out;

		for (i = 0; i < se_mem->se_len; i++)
			*(addr + se_mem->se_off + i) ^= *(buf + offset + i);

		offset += se_mem->se_len;
		kunmap_atomic(addr, KM_USER0);
	}
out:
	kfree(buf);
}

/*
 * Used to obtain Sense Data from underlying Linux/SCSI struct scsi_cmnd
 */
static int transport_get_sense_data(struct se_cmd *cmd)
{
	unsigned char *buffer = cmd->sense_buffer, *sense_buffer = NULL;
	struct se_device *dev;
	struct se_task *task = NULL, *task_tmp;
	unsigned long flags;
	u32 offset = 0;

	WARN_ON(!cmd->se_lun);

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		return 0;
	}

	list_for_each_entry_safe(task, task_tmp,
				&cmd->t_task.t_task_list, t_list) {

		if (!task->task_sense)
			continue;

		dev = task->se_dev;
		if (!(dev))
			continue;

		if (!dev->transport->get_sense_buffer) {
			printk(KERN_ERR "dev->transport->get_sense_buffer"
					" is NULL\n");
			continue;
		}

		sense_buffer = dev->transport->get_sense_buffer(task);
		if (!(sense_buffer)) {
			printk(KERN_ERR "ITT[0x%08x]_TASK[%d]: Unable to locate"
				" sense buffer for task with sense\n",
				cmd->se_tfo->get_task_tag(cmd), task->task_no);
			continue;
		}
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

		offset = cmd->se_tfo->set_fabric_sense_len(cmd,
				TRANSPORT_SENSE_BUFFER);

		memcpy(&buffer[offset], sense_buffer,
				TRANSPORT_SENSE_BUFFER);
		cmd->scsi_status = task->task_scsi_status;
		/* Automatically padded */
		cmd->scsi_sense_length =
				(TRANSPORT_SENSE_BUFFER + offset);

		printk(KERN_INFO "HBA_[%u]_PLUG[%s]: Set SAM STATUS: 0x%02x"
				" and sense\n",
			dev->se_hba->hba_id, dev->transport->name,
				cmd->scsi_status);
		return 0;
	}
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

	return -1;
}

static int transport_allocate_resources(struct se_cmd *cmd)
{
	u32 length = cmd->data_length;

	if ((cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) ||
	    (cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB))
		return transport_generic_get_mem(cmd, length, PAGE_SIZE);
	else if (cmd->se_cmd_flags & SCF_SCSI_CONTROL_NONSG_IO_CDB)
		return transport_generic_allocate_buf(cmd, length);
	else
		return 0;
}

static int
transport_handle_reservation_conflict(struct se_cmd *cmd)
{
	cmd->transport_wait_for_tasks = &transport_nop_wait_for_tasks;
	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
	cmd->se_cmd_flags |= SCF_SCSI_RESERVATION_CONFLICT;
	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);
	return -EINVAL;
}

/*	transport_generic_cmd_sequencer():
 *
 *	Generic Command Sequencer that should work for most DAS transport
 *	drivers.
 *
 *	Called from transport_generic_allocate_tasks() in the $FABRIC_MOD
 *	RX Thread.
 *
 *	FIXME: Need to support other SCSI OPCODES where as well.
 */
static int transport_generic_cmd_sequencer(
	struct se_cmd *cmd,
	unsigned char *cdb)
{
	struct se_device *dev = cmd->se_dev;
	struct se_subsystem_dev *su_dev = dev->se_sub_dev;
	int ret = 0, sector_ret = 0, passthrough;
	u32 sectors = 0, size = 0, pr_reg_type = 0;
	u16 service_action;
	u8 alua_ascq = 0;
	/*
	 * Check for an existing UNIT ATTENTION condition
	 */
	if (core_scsi3_ua_check(cmd, cdb) < 0) {
		cmd->transport_wait_for_tasks =
				&transport_nop_wait_for_tasks;
		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
		cmd->scsi_sense_reason = TCM_CHECK_CONDITION_UNIT_ATTENTION;
		return -EINVAL;
	}
	/*
	 * Check status of Asymmetric Logical Unit Assignment port
	 */
	ret = su_dev->t10_alua.alua_state_check(cmd, cdb, &alua_ascq);
	if (ret != 0) {
		cmd->transport_wait_for_tasks = &transport_nop_wait_for_tasks;
		/*
		 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
		 * The ALUA additional sense code qualifier (ASCQ) is determined
		 * by the ALUA primary or secondary access state..
		 */
		if (ret > 0) {
#if 0
			printk(KERN_INFO "[%s]: ALUA TG Port not available,"
				" SenseKey: NOT_READY, ASC/ASCQ: 0x04/0x%02x\n",
				cmd->se_tfo->get_fabric_name(), alua_ascq);
#endif
			transport_set_sense_codes(cmd, 0x04, alua_ascq);
			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
			cmd->scsi_sense_reason = TCM_CHECK_CONDITION_NOT_READY;
			return -EINVAL;
		}
		goto out_invalid_cdb_field;
	}
	/*
	 * Check status for SPC-3 Persistent Reservations
	 */
	if (su_dev->t10_pr.pr_ops.t10_reservation_check(cmd, &pr_reg_type) != 0) {
		if (su_dev->t10_pr.pr_ops.t10_seq_non_holder(
					cmd, cdb, pr_reg_type) != 0)
			return transport_handle_reservation_conflict(cmd);
		/*
		 * This means the CDB is allowed for the SCSI Initiator port
		 * when said port is *NOT* holding the legacy SPC-2 or
		 * SPC-3 Persistent Reservation.
		 */
	}

	switch (cdb[0]) {
	case READ_6:
		sectors = transport_get_sectors_6(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->transport_split_cdb = &split_cdb_XX_6;
		cmd->t_task.t_task_lba = transport_lba_21(cdb);
		cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;
		break;
	case READ_10:
		sectors = transport_get_sectors_10(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->transport_split_cdb = &split_cdb_XX_10;
		cmd->t_task.t_task_lba = transport_lba_32(cdb);
		cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;
		break;
	case READ_12:
		sectors = transport_get_sectors_12(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->transport_split_cdb = &split_cdb_XX_12;
		cmd->t_task.t_task_lba = transport_lba_32(cdb);
		cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;
		break;
	case READ_16:
		sectors = transport_get_sectors_16(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->transport_split_cdb = &split_cdb_XX_16;
		cmd->t_task.t_task_lba = transport_lba_64(cdb);
		cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;
		break;
	case WRITE_6:
		sectors = transport_get_sectors_6(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->transport_split_cdb = &split_cdb_XX_6;
		cmd->t_task.t_task_lba = transport_lba_21(cdb);
		cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;
		break;
	case WRITE_10:
		sectors = transport_get_sectors_10(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->transport_split_cdb = &split_cdb_XX_10;
		cmd->t_task.t_task_lba = transport_lba_32(cdb);
		cmd->t_task.t_tasks_fua = (cdb[1] & 0x8);
		cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;
		break;
	case WRITE_12:
		sectors = transport_get_sectors_12(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->transport_split_cdb = &split_cdb_XX_12;
		cmd->t_task.t_task_lba = transport_lba_32(cdb);
		cmd->t_task.t_tasks_fua = (cdb[1] & 0x8);
		cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;
		break;
	case WRITE_16:
		sectors = transport_get_sectors_16(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->transport_split_cdb = &split_cdb_XX_16;
		cmd->t_task.t_task_lba = transport_lba_64(cdb);
		cmd->t_task.t_tasks_fua = (cdb[1] & 0x8);
		cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;
		break;
	case XDWRITEREAD_10:
		if ((cmd->data_direction != DMA_TO_DEVICE) ||
		    !(cmd->t_task.t_tasks_bidi))
			goto out_invalid_cdb_field;
		sectors = transport_get_sectors_10(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->transport_split_cdb = &split_cdb_XX_10;
		cmd->t_task.t_task_lba = transport_lba_32(cdb);
		cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;
		passthrough = (dev->transport->transport_type ==
				TRANSPORT_PLUGIN_PHBA_PDEV);
		/*
		 * Skip the remaining assignments for TCM/PSCSI passthrough
		 */
		if (passthrough)
			break;
		/*
		 * Setup BIDI XOR callback to be run during transport_generic_complete_ok()
		 */
		cmd->transport_complete_callback = &transport_xor_callback;
		cmd->t_task.t_tasks_fua = (cdb[1] & 0x8);
		break;
	case VARIABLE_LENGTH_CMD:
		service_action = get_unaligned_be16(&cdb[8]);
		/*
		 * Determine if this is TCM/PSCSI device and we should disable
		 * internal emulation for this CDB.
		 */
		passthrough = (dev->transport->transport_type ==
					TRANSPORT_PLUGIN_PHBA_PDEV);

		switch (service_action) {
		case XDWRITEREAD_32:
			sectors = transport_get_sectors_32(cdb, cmd, &sector_ret);
			if (sector_ret)
				goto out_unsupported_cdb;
			size = transport_get_size(sectors, cdb, cmd);
			/*
			 * Use WRITE_32 and READ_32 opcodes for the emulated
			 * XDWRITE_READ_32 logic.
			 */
			cmd->transport_split_cdb = &split_cdb_XX_32;
			cmd->t_task.t_task_lba = transport_lba_64_ext(cdb);
			cmd->se_cmd_flags |= SCF_SCSI_DATA_SG_IO_CDB;

			/*
			 * Skip the remaining assignments for TCM/PSCSI passthrough
			 */
			if (passthrough)
				break;

			/*
			 * Setup BIDI XOR callback to be run during
			 * transport_generic_complete_ok()
			 */
			cmd->transport_complete_callback = &transport_xor_callback;
			cmd->t_task.t_tasks_fua = (cdb[10] & 0x8);
			break;
		case WRITE_SAME_32:
			sectors = transport_get_sectors_32(cdb, cmd, &sector_ret);
			if (sector_ret)
				goto out_unsupported_cdb;
			size = transport_get_size(sectors, cdb, cmd);
			cmd->t_task.t_task_lba = get_unaligned_be64(&cdb[12]);
			cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;

			/*
			 * Skip the remaining assignments for TCM/PSCSI passthrough
			 */
			if (passthrough)
				break;

			if ((cdb[10] & 0x04) || (cdb[10] & 0x02)) {
				printk(KERN_ERR "WRITE_SAME PBDATA and LBDATA"
					" bits not supported for Block Discard"
					" Emulation\n");
				goto out_invalid_cdb_field;
			}
			/*
			 * Currently for the emulated case we only accept
			 * tpws with the UNMAP=1 bit set.
			 */
			if (!(cdb[10] & 0x08)) {
				printk(KERN_ERR "WRITE_SAME w/o UNMAP bit not"
					" supported for Block Discard Emulation\n");
				goto out_invalid_cdb_field;
			}
			break;
		default:
			printk(KERN_ERR "VARIABLE_LENGTH_CMD service action"
				" 0x%04x not supported\n", service_action);
			goto out_unsupported_cdb;
		}
		break;
	case MAINTENANCE_IN:
		if (dev->transport->get_device_type(dev) != TYPE_ROM) {
			/* MAINTENANCE_IN from SCC-2 */
			/*
			 * Check for emulated MI_REPORT_TARGET_PGS.
			 */
			if (cdb[1] == MI_REPORT_TARGET_PGS) {
				cmd->transport_emulate_cdb =
				(su_dev->t10_alua.alua_type ==
				 SPC3_ALUA_EMULATED) ?
				core_emulate_report_target_port_groups :
				NULL;
			}
			size = (cdb[6] << 24) | (cdb[7] << 16) |
			       (cdb[8] << 8) | cdb[9];
		} else {
			/* GPCMD_SEND_KEY from multi media commands */
			size = (cdb[8] << 8) + cdb[9];
		}
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case MODE_SELECT:
		size = cdb[4];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
		break;
	case MODE_SELECT_10:
		size = (cdb[7] << 8) + cdb[8];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
		break;
	case MODE_SENSE:
		size = cdb[4];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case MODE_SENSE_10:
	case GPCMD_READ_BUFFER_CAPACITY:
	case GPCMD_SEND_OPC:
	case LOG_SELECT:
	case LOG_SENSE:
		size = (cdb[7] << 8) + cdb[8];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case READ_BLOCK_LIMITS:
		size = READ_BLOCK_LEN;
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case GPCMD_GET_CONFIGURATION:
	case GPCMD_READ_FORMAT_CAPACITIES:
	case GPCMD_READ_DISC_INFO:
	case GPCMD_READ_TRACK_RZONE_INFO:
		size = (cdb[7] << 8) + cdb[8];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
		break;
	case PERSISTENT_RESERVE_IN:
	case PERSISTENT_RESERVE_OUT:
		cmd->transport_emulate_cdb =
			(su_dev->t10_pr.res_type ==
			 SPC3_PERSISTENT_RESERVATIONS) ?
			core_scsi3_emulate_pr : NULL;
		size = (cdb[7] << 8) + cdb[8];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case GPCMD_MECHANISM_STATUS:
	case GPCMD_READ_DVD_STRUCTURE:
		size = (cdb[8] << 8) + cdb[9];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
		break;
	case READ_POSITION:
		size = READ_POSITION_LEN;
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case MAINTENANCE_OUT:
		if (dev->transport->get_device_type(dev) != TYPE_ROM) {
			/* MAINTENANCE_OUT from SCC-2
			 *
			 * Check for emulated MO_SET_TARGET_PGS.
			 */
			if (cdb[1] == MO_SET_TARGET_PGS) {
				cmd->transport_emulate_cdb =
				(su_dev->t10_alua.alua_type ==
					SPC3_ALUA_EMULATED) ?
				core_emulate_set_target_port_groups :
				NULL;
			}

			size = (cdb[6] << 24) | (cdb[7] << 16) |
			       (cdb[8] << 8) | cdb[9];
		} else  {
			/* GPCMD_REPORT_KEY from multi media commands */
			size = (cdb[8] << 8) + cdb[9];
		}
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case INQUIRY:
		size = (cdb[3] << 8) + cdb[4];
		/*
		 * Do implict HEAD_OF_QUEUE processing for INQUIRY.
		 * See spc4r17 section 5.3
		 */
		if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
			cmd->sam_task_attr = MSG_HEAD_TAG;
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case READ_BUFFER:
		size = (cdb[6] << 16) + (cdb[7] << 8) + cdb[8];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case READ_CAPACITY:
		size = READ_CAP_LEN;
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case READ_MEDIA_SERIAL_NUMBER:
	case SECURITY_PROTOCOL_IN:
	case SECURITY_PROTOCOL_OUT:
		size = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case SERVICE_ACTION_IN:
	case ACCESS_CONTROL_IN:
	case ACCESS_CONTROL_OUT:
	case EXTENDED_COPY:
	case READ_ATTRIBUTE:
	case RECEIVE_COPY_RESULTS:
	case WRITE_ATTRIBUTE:
		size = (cdb[10] << 24) | (cdb[11] << 16) |
		       (cdb[12] << 8) | cdb[13];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case RECEIVE_DIAGNOSTIC:
	case SEND_DIAGNOSTIC:
		size = (cdb[3] << 8) | cdb[4];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
/* #warning FIXME: Figure out correct GPCMD_READ_CD blocksize. */
#if 0
	case GPCMD_READ_CD:
		sectors = (cdb[6] << 16) + (cdb[7] << 8) + cdb[8];
		size = (2336 * sectors);
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
#endif
	case READ_TOC:
		size = cdb[8];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case REQUEST_SENSE:
		size = cdb[4];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case READ_ELEMENT_STATUS:
		size = 65536 * cdb[7] + 256 * cdb[8] + cdb[9];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case WRITE_BUFFER:
		size = (cdb[6] << 16) + (cdb[7] << 8) + cdb[8];
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case RESERVE:
	case RESERVE_10:
		/*
		 * The SPC-2 RESERVE does not contain a size in the SCSI CDB.
		 * Assume the passthrough or $FABRIC_MOD will tell us about it.
		 */
		if (cdb[0] == RESERVE_10)
			size = (cdb[7] << 8) | cdb[8];
		else
			size = cmd->data_length;

		/*
		 * Setup the legacy emulated handler for SPC-2 and
		 * >= SPC-3 compatible reservation handling (CRH=1)
		 * Otherwise, we assume the underlying SCSI logic is
		 * is running in SPC_PASSTHROUGH, and wants reservations
		 * emulation disabled.
		 */
		cmd->transport_emulate_cdb =
				(su_dev->t10_pr.res_type !=
				 SPC_PASSTHROUGH) ?
				core_scsi2_emulate_crh : NULL;
		cmd->se_cmd_flags |= SCF_SCSI_NON_DATA_CDB;
		break;
	case RELEASE:
	case RELEASE_10:
		/*
		 * The SPC-2 RELEASE does not contain a size in the SCSI CDB.
		 * Assume the passthrough or $FABRIC_MOD will tell us about it.
		*/
		if (cdb[0] == RELEASE_10)
			size = (cdb[7] << 8) | cdb[8];
		else
			size = cmd->data_length;

		cmd->transport_emulate_cdb =
				(su_dev->t10_pr.res_type !=
				 SPC_PASSTHROUGH) ?
				core_scsi2_emulate_crh : NULL;
		cmd->se_cmd_flags |= SCF_SCSI_NON_DATA_CDB;
		break;
	case SYNCHRONIZE_CACHE:
	case 0x91: /* SYNCHRONIZE_CACHE_16: */
		/*
		 * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
		 */
		if (cdb[0] == SYNCHRONIZE_CACHE) {
			sectors = transport_get_sectors_10(cdb, cmd, &sector_ret);
			cmd->t_task.t_task_lba = transport_lba_32(cdb);
		} else {
			sectors = transport_get_sectors_16(cdb, cmd, &sector_ret);
			cmd->t_task.t_task_lba = transport_lba_64(cdb);
		}
		if (sector_ret)
			goto out_unsupported_cdb;

		size = transport_get_size(sectors, cdb, cmd);
		cmd->se_cmd_flags |= SCF_SCSI_NON_DATA_CDB;

		/*
		 * For TCM/pSCSI passthrough, skip cmd->transport_emulate_cdb()
		 */
		if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
			break;
		/*
		 * Set SCF_EMULATE_CDB_ASYNC to ensure asynchronous operation
		 * for SYNCHRONIZE_CACHE* Immed=1 case in __transport_execute_tasks()
		 */
		cmd->se_cmd_flags |= SCF_EMULATE_CDB_ASYNC;
		/*
		 * Check to ensure that LBA + Range does not exceed past end of
		 * device.
		 */
		if (transport_get_sectors(cmd) < 0)
			goto out_invalid_cdb_field;
		break;
	case UNMAP:
		size = get_unaligned_be16(&cdb[7]);
		passthrough = (dev->transport->transport_type ==
				TRANSPORT_PLUGIN_PHBA_PDEV);
		/*
		 * Determine if the received UNMAP used to for direct passthrough
		 * into Linux/SCSI with struct request via TCM/pSCSI or we are
		 * signaling the use of internal transport_generic_unmap() emulation
		 * for UNMAP -> Linux/BLOCK disbard with TCM/IBLOCK and TCM/FILEIO
		 * subsystem plugin backstores.
		 */
		if (!(passthrough))
			cmd->se_cmd_flags |= SCF_EMULATE_SYNC_UNMAP;

		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	case WRITE_SAME_16:
		sectors = transport_get_sectors_16(cdb, cmd, &sector_ret);
		if (sector_ret)
			goto out_unsupported_cdb;
		size = transport_get_size(sectors, cdb, cmd);
		cmd->t_task.t_task_lba = get_unaligned_be16(&cdb[2]);
		passthrough = (dev->transport->transport_type ==
				TRANSPORT_PLUGIN_PHBA_PDEV);
		/*
		 * Determine if the received WRITE_SAME_16 is used to for direct
		 * passthrough into Linux/SCSI with struct request via TCM/pSCSI
		 * or we are signaling the use of internal WRITE_SAME + UNMAP=1
		 * emulation for -> Linux/BLOCK disbard with TCM/IBLOCK and
		 * TCM/FILEIO subsystem plugin backstores.
		 */
		if (!(passthrough)) {
			if ((cdb[1] & 0x04) || (cdb[1] & 0x02)) {
				printk(KERN_ERR "WRITE_SAME PBDATA and LBDATA"
					" bits not supported for Block Discard"
					" Emulation\n");
				goto out_invalid_cdb_field;
			}
			/*
			 * Currently for the emulated case we only accept
			 * tpws with the UNMAP=1 bit set.
			 */
			if (!(cdb[1] & 0x08)) {
				printk(KERN_ERR "WRITE_SAME w/o UNMAP bit not "
					" supported for Block Discard Emulation\n");
				goto out_invalid_cdb_field;
			}
		}
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
		break;
	case ALLOW_MEDIUM_REMOVAL:
	case GPCMD_CLOSE_TRACK:
	case ERASE:
	case INITIALIZE_ELEMENT_STATUS:
	case GPCMD_LOAD_UNLOAD:
	case REZERO_UNIT:
	case SEEK_10:
	case GPCMD_SET_SPEED:
	case SPACE:
	case START_STOP:
	case TEST_UNIT_READY:
	case VERIFY:
	case WRITE_FILEMARKS:
	case MOVE_MEDIUM:
		cmd->se_cmd_flags |= SCF_SCSI_NON_DATA_CDB;
		break;
	case REPORT_LUNS:
		cmd->transport_emulate_cdb =
				transport_core_report_lun_response;
		size = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
		/*
		 * Do implict HEAD_OF_QUEUE processing for REPORT_LUNS
		 * See spc4r17 section 5.3
		 */
		if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
			cmd->sam_task_attr = MSG_HEAD_TAG;
		cmd->se_cmd_flags |= SCF_SCSI_CONTROL_NONSG_IO_CDB;
		break;
	default:
		printk(KERN_WARNING "TARGET_CORE[%s]: Unsupported SCSI Opcode"
			" 0x%02x, sending CHECK_CONDITION.\n",
			cmd->se_tfo->get_fabric_name(), cdb[0]);
		cmd->transport_wait_for_tasks = &transport_nop_wait_for_tasks;
		goto out_unsupported_cdb;
	}

	if (size != cmd->data_length) {
		printk(KERN_WARNING "TARGET_CORE[%s]: Expected Transfer Length:"
			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
				cmd->data_length, size, cdb[0]);

		cmd->cmd_spdtl = size;

		if (cmd->data_direction == DMA_TO_DEVICE) {
			printk(KERN_ERR "Rejecting underflow/overflow"
					" WRITE data\n");
			goto out_invalid_cdb_field;
		}
		/*
		 * Reject READ_* or WRITE_* with overflow/underflow for
		 * type SCF_SCSI_DATA_SG_IO_CDB.
		 */
		if (!(ret) && (dev->se_sub_dev->se_dev_attrib.block_size != 512))  {
			printk(KERN_ERR "Failing OVERFLOW/UNDERFLOW for LBA op"
				" CDB on non 512-byte sector setup subsystem"
				" plugin: %s\n", dev->transport->name);
			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
			goto out_invalid_cdb_field;
		}

		if (size > cmd->data_length) {
			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
			cmd->residual_count = (size - cmd->data_length);
		} else {
			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
			cmd->residual_count = (cmd->data_length - size);
		}
		cmd->data_length = size;
	}

	transport_set_supported_SAM_opcode(cmd);
	return ret;

out_unsupported_cdb:
	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
	cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
	return -EINVAL;
out_invalid_cdb_field:
	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
	cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
	return -EINVAL;
}

static inline void transport_release_tasks(struct se_cmd *);

/*
 * This function will copy a contiguous *src buffer into a destination
 * struct scatterlist array.
 */
static void transport_memcpy_write_contig(
	struct se_cmd *cmd,
	struct scatterlist *sg_d,
	unsigned char *src)
{
	u32 i = 0, length = 0, total_length = cmd->data_length;
	void *dst;

	while (total_length) {
		length = sg_d[i].length;

		if (length > total_length)
			length = total_length;

		dst = sg_virt(&sg_d[i]);

		memcpy(dst, src, length);

		if (!(total_length -= length))
			return;

		src += length;
		i++;
	}
}

/*
 * This function will copy a struct scatterlist array *sg_s into a destination
 * contiguous *dst buffer.
 */
static void transport_memcpy_read_contig(
	struct se_cmd *cmd,
	unsigned char *dst,
	struct scatterlist *sg_s)
{
	u32 i = 0, length = 0, total_length = cmd->data_length;
	void *src;

	while (total_length) {
		length = sg_s[i].length;

		if (length > total_length)
			length = total_length;

		src = sg_virt(&sg_s[i]);

		memcpy(dst, src, length);

		if (!(total_length -= length))
			return;

		dst += length;
		i++;
	}
}

static void transport_memcpy_se_mem_read_contig(
	struct se_cmd *cmd,
	unsigned char *dst,
	struct list_head *se_mem_list)
{
	struct se_mem *se_mem;
	void *src;
	u32 length = 0, total_length = cmd->data_length;

	list_for_each_entry(se_mem, se_mem_list, se_list) {
		length = se_mem->se_len;

		if (length > total_length)
			length = total_length;

		src = page_address(se_mem->se_page) + se_mem->se_off;

		memcpy(dst, src, length);

		if (!(total_length -= length))
			return;

		dst += length;
	}
}

/*
 * Called from transport_generic_complete_ok() and
 * transport_generic_request_failure() to determine which dormant/delayed
 * and ordered cmds need to have their tasks added to the execution queue.
 */
static void transport_complete_task_attr(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	struct se_cmd *cmd_p, *cmd_tmp;
	int new_active_tasks = 0;

	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
		atomic_dec(&dev->simple_cmds);
		smp_mb__after_atomic_dec();
		dev->dev_cur_ordered_id++;
		DEBUG_STA("Incremented dev->dev_cur_ordered_id: %u for"
			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
			cmd->se_ordered_id);
	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
		atomic_dec(&dev->dev_hoq_count);
		smp_mb__after_atomic_dec();
		dev->dev_cur_ordered_id++;
		DEBUG_STA("Incremented dev_cur_ordered_id: %u for"
			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
			cmd->se_ordered_id);
	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
		spin_lock(&dev->ordered_cmd_lock);
		list_del(&cmd->se_ordered_node);
		atomic_dec(&dev->dev_ordered_sync);
		smp_mb__after_atomic_dec();
		spin_unlock(&dev->ordered_cmd_lock);

		dev->dev_cur_ordered_id++;
		DEBUG_STA("Incremented dev_cur_ordered_id: %u for ORDERED:"
			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
	}
	/*
	 * Process all commands up to the last received
	 * ORDERED task attribute which requires another blocking
	 * boundary
	 */
	spin_lock(&dev->delayed_cmd_lock);
	list_for_each_entry_safe(cmd_p, cmd_tmp,
			&dev->delayed_cmd_list, se_delayed_node) {

		list_del(&cmd_p->se_delayed_node);
		spin_unlock(&dev->delayed_cmd_lock);

		DEBUG_STA("Calling add_tasks() for"
			" cmd_p: 0x%02x Task Attr: 0x%02x"
			" Dormant -> Active, se_ordered_id: %u\n",
			T_TASK(cmd_p)->t_task_cdb[0],
			cmd_p->sam_task_attr, cmd_p->se_ordered_id);

		transport_add_tasks_from_cmd(cmd_p);
		new_active_tasks++;

		spin_lock(&dev->delayed_cmd_lock);
		if (cmd_p->sam_task_attr == MSG_ORDERED_TAG)
			break;
	}
	spin_unlock(&dev->delayed_cmd_lock);
	/*
	 * If new tasks have become active, wake up the transport thread
	 * to do the processing of the Active tasks.
	 */
	if (new_active_tasks != 0)
		wake_up_interruptible(&dev->dev_queue_obj.thread_wq);
}

static void transport_generic_complete_ok(struct se_cmd *cmd)
{
	int reason = 0;
	/*
	 * Check if we need to move delayed/dormant tasks from cmds on the
	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
	 * Attribute.
	 */
	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
		transport_complete_task_attr(cmd);
	/*
	 * Check if we need to retrieve a sense buffer from
	 * the struct se_cmd in question.
	 */
	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
		if (transport_get_sense_data(cmd) < 0)
			reason = TCM_NON_EXISTENT_LUN;

		/*
		 * Only set when an struct se_task->task_scsi_status returned
		 * a non GOOD status.
		 */
		if (cmd->scsi_status) {
			transport_send_check_condition_and_sense(
					cmd, reason, 1);
			transport_lun_remove_cmd(cmd);
			transport_cmd_check_stop_to_fabric(cmd);
			return;
		}
	}
	/*
	 * Check for a callback, used by amongst other things
	 * XDWRITE_READ_10 emulation.
	 */
	if (cmd->transport_complete_callback)
		cmd->transport_complete_callback(cmd);

	switch (cmd->data_direction) {
	case DMA_FROM_DEVICE:
		spin_lock(&cmd->se_lun->lun_sep_lock);
		if (cmd->se_lun->lun_sep) {
			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
					cmd->data_length;
		}
		spin_unlock(&cmd->se_lun->lun_sep_lock);
		/*
		 * If enabled by TCM fabirc module pre-registered SGL
		 * memory, perform the memcpy() from the TCM internal
		 * contigious buffer back to the original SGL.
		 */
		if (cmd->se_cmd_flags & SCF_PASSTHROUGH_CONTIG_TO_SG)
			transport_memcpy_write_contig(cmd,
				 cmd->t_task.t_task_pt_sgl,
				 cmd->t_task.t_task_buf);

		cmd->se_tfo->queue_data_in(cmd);
		break;
	case DMA_TO_DEVICE:
		spin_lock(&cmd->se_lun->lun_sep_lock);
		if (cmd->se_lun->lun_sep) {
			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
				cmd->data_length;
		}
		spin_unlock(&cmd->se_lun->lun_sep_lock);
		/*
		 * Check if we need to send READ payload for BIDI-COMMAND
		 */
		if (!list_empty(&cmd->t_task.t_mem_bidi_list)) {
			spin_lock(&cmd->se_lun->lun_sep_lock);
			if (cmd->se_lun->lun_sep) {
				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
					cmd->data_length;
			}
			spin_unlock(&cmd->se_lun->lun_sep_lock);
			cmd->se_tfo->queue_data_in(cmd);
			break;
		}
		/* Fall through for DMA_TO_DEVICE */
	case DMA_NONE:
		cmd->se_tfo->queue_status(cmd);
		break;
	default:
		break;
	}

	transport_lun_remove_cmd(cmd);
	transport_cmd_check_stop_to_fabric(cmd);
}

static void transport_free_dev_tasks(struct se_cmd *cmd)
{
	struct se_task *task, *task_tmp;
	unsigned long flags;

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	list_for_each_entry_safe(task, task_tmp,
				&cmd->t_task.t_task_list, t_list) {
		if (atomic_read(&task->task_active))
			continue;

		kfree(task->task_sg_bidi);
		kfree(task->task_sg);

		list_del(&task->t_list);

		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		if (task->se_dev)
			task->se_dev->transport->free_task(task);
		else
			printk(KERN_ERR "task[%u] - task->se_dev is NULL\n",
				task->task_no);
		spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	}
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
}

static inline void transport_free_pages(struct se_cmd *cmd)
{
	struct se_mem *se_mem, *se_mem_tmp;
	int free_page = 1;

	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
		free_page = 0;
	if (cmd->se_dev->transport->do_se_mem_map)
		free_page = 0;

	if (cmd->t_task.t_task_buf) {
		kfree(cmd->t_task.t_task_buf);
		cmd->t_task.t_task_buf = NULL;
		return;
	}

	/*
	 * Caller will handle releasing of struct se_mem.
	 */
	if (cmd->se_cmd_flags & SCF_CMD_PASSTHROUGH_NOALLOC)
		return;

	list_for_each_entry_safe(se_mem, se_mem_tmp,
			&cmd->t_task.t_mem_list, se_list) {
		/*
		 * We only release call __free_page(struct se_mem->se_page) when
		 * SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC is NOT in use,
		 */
		if (free_page)
			__free_page(se_mem->se_page);

		list_del(&se_mem->se_list);
		kmem_cache_free(se_mem_cache, se_mem);
	}
	cmd->t_task.t_tasks_se_num = 0;

	list_for_each_entry_safe(se_mem, se_mem_tmp,
				 &cmd->t_task.t_mem_bidi_list, se_list) {
		/*
		 * We only release call __free_page(struct se_mem->se_page) when
		 * SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC is NOT in use,
		 */
		if (free_page)
			__free_page(se_mem->se_page);

		list_del(&se_mem->se_list);
		kmem_cache_free(se_mem_cache, se_mem);
	}
	cmd->t_task.t_tasks_se_bidi_num = 0;
}

static inline void transport_release_tasks(struct se_cmd *cmd)
{
	transport_free_dev_tasks(cmd);
}

static inline int transport_dec_and_check(struct se_cmd *cmd)
{
	unsigned long flags;

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	if (atomic_read(&cmd->t_task.t_fe_count)) {
		if (!(atomic_dec_and_test(&cmd->t_task.t_fe_count))) {
			spin_unlock_irqrestore(&cmd->t_task.t_state_lock,
					flags);
			return 1;
		}
	}

	if (atomic_read(&cmd->t_task.t_se_count)) {
		if (!(atomic_dec_and_test(&cmd->t_task.t_se_count))) {
			spin_unlock_irqrestore(&cmd->t_task.t_state_lock,
					flags);
			return 1;
		}
	}
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

	return 0;
}

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

	if (transport_dec_and_check(cmd))
		return;

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

	transport_release_tasks(cmd);
free_pages:
	transport_free_pages(cmd);
	transport_free_se_cmd(cmd);
	cmd->se_tfo->release_cmd_direct(cmd);
}

static int transport_generic_remove(
	struct se_cmd *cmd,
	int release_to_pool,
	int session_reinstatement)
{
	unsigned long flags;

	if (transport_dec_and_check(cmd)) {
		if (session_reinstatement) {
			spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
			transport_all_task_dev_remove_state(cmd);
			spin_unlock_irqrestore(&cmd->t_task.t_state_lock,
					flags);
		}
		return 1;
	}

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

	transport_release_tasks(cmd);

free_pages:
	transport_free_pages(cmd);

	if (release_to_pool) {
		transport_release_cmd_to_pool(cmd);
	} else {
		transport_free_se_cmd(cmd);
		cmd->se_tfo->release_cmd_direct(cmd);
	}

	return 0;
}

/*
 * transport_generic_map_mem_to_cmd - Perform SGL -> struct se_mem map
 * @cmd:  Associated se_cmd descriptor
 * @mem:  SGL style memory for TCM WRITE / READ
 * @sg_mem_num: Number of SGL elements
 * @mem_bidi_in: SGL style memory for TCM BIDI READ
 * @sg_mem_bidi_num: Number of BIDI READ SGL elements
 *
 * Return: nonzero return cmd was rejected for -ENOMEM or inproper usage
 * of parameters.
 */
int transport_generic_map_mem_to_cmd(
	struct se_cmd *cmd,
	struct scatterlist *sgl,
	u32 sgl_count,
	struct scatterlist *sgl_bidi,
	u32 sgl_bidi_count)
{
	u32 mapped_sg_count = 0;
	int ret;

	if (!sgl || !sgl_count)
		return 0;

	/*
	 * Convert sgls (sgl, sgl_bidi) to list of se_mems
	 */
	if ((cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) ||
	    (cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB)) {
		/*
		 * For CDB using TCM struct se_mem linked list scatterlist memory
		 * processed into a TCM struct se_subsystem_dev, we do the mapping
		 * from the passed physical memory to struct se_mem->se_page here.
		 */
		ret = transport_map_sg_to_mem(cmd,
			&cmd->t_task.t_mem_list, sgl, &mapped_sg_count);
		if (ret < 0)
			return -ENOMEM;

		cmd->t_task.t_tasks_se_num = mapped_sg_count;
		/*
		 * Setup BIDI READ list of struct se_mem elements
		 */
		if (sgl_bidi && sgl_bidi_count) {
			mapped_sg_count = 0;
			ret = transport_map_sg_to_mem(cmd,
				&cmd->t_task.t_mem_bidi_list, sgl_bidi,
				&mapped_sg_count);
			if (ret < 0)
				return -ENOMEM;

			cmd->t_task.t_tasks_se_bidi_num = mapped_sg_count;
		}
		cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;

	} else if (cmd->se_cmd_flags & SCF_SCSI_CONTROL_NONSG_IO_CDB) {
		if (sgl_bidi || sgl_bidi_count) {
			printk(KERN_ERR "BIDI-Commands not supported using "
				"SCF_SCSI_CONTROL_NONSG_IO_CDB\n");
			return -ENOSYS;
		}
		/*
		 * For incoming CDBs using a contiguous buffer internall with TCM,
		 * save the passed struct scatterlist memory.  After TCM storage object
		 * processing has completed for this struct se_cmd, TCM core will call
		 * transport_memcpy_[write,read]_contig() as necessary from
		 * transport_generic_complete_ok() and transport_write_pending() in order
		 * to copy the TCM buffer to/from the original passed *mem in SGL ->
		 * struct scatterlist format.
		 */
		cmd->se_cmd_flags |= SCF_PASSTHROUGH_CONTIG_TO_SG;
		cmd->t_task.t_task_pt_sgl = sgl;
		/* don't need sgl count? We assume it contains cmd->data_length data */
	}

	return 0;
}
EXPORT_SYMBOL(transport_generic_map_mem_to_cmd);


static inline long long transport_dev_end_lba(struct se_device *dev)
{
	return dev->transport->get_blocks(dev) + 1;
}

static int transport_get_sectors(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;

	cmd->t_task.t_tasks_sectors =
		(cmd->data_length / dev->se_sub_dev->se_dev_attrib.block_size);
	if (!(cmd->t_task.t_tasks_sectors))
		cmd->t_task.t_tasks_sectors = 1;

	if (dev->transport->get_device_type(dev) != TYPE_DISK)
		return 0;

	if ((cmd->t_task.t_task_lba + cmd->t_task.t_tasks_sectors) >
	     transport_dev_end_lba(dev)) {
		printk(KERN_ERR "LBA: %llu Sectors: %u exceeds"
			" transport_dev_end_lba(): %llu\n",
			cmd->t_task.t_task_lba, cmd->t_task.t_tasks_sectors,
			transport_dev_end_lba(dev));
		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
		cmd->scsi_sense_reason = TCM_SECTOR_COUNT_TOO_MANY;
		return PYX_TRANSPORT_REQ_TOO_MANY_SECTORS;
	}

	return 0;
}

static int transport_new_cmd_obj(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	u32 task_cdbs = 0, rc;

	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB)) {
		task_cdbs++;
		cmd->t_task.t_task_cdbs++;
	} else {
		int set_counts = 1;

		/*
		 * Setup any BIDI READ tasks and memory from
		 * cmd->t_task.t_mem_bidi_list so the READ struct se_tasks
		 * are queued first for the non pSCSI passthrough case.
		 */
		if (!list_empty(&cmd->t_task.t_mem_bidi_list) &&
		    (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV)) {
			rc = transport_generic_get_cdb_count(cmd,
				cmd->t_task.t_task_lba,
				cmd->t_task.t_tasks_sectors,
				DMA_FROM_DEVICE, &cmd->t_task.t_mem_bidi_list,
				set_counts);
			if (!(rc)) {
				cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
				cmd->scsi_sense_reason =
					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
				return PYX_TRANSPORT_LU_COMM_FAILURE;
			}
			set_counts = 0;
		}
		/*
		 * Setup the tasks and memory from cmd->t_task.t_mem_list
		 * Note for BIDI transfers this will contain the WRITE payload
		 */
		task_cdbs = transport_generic_get_cdb_count(cmd,
				cmd->t_task.t_task_lba,
				cmd->t_task.t_tasks_sectors,
				cmd->data_direction, &cmd->t_task.t_mem_list,
				set_counts);
		if (!(task_cdbs)) {
			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
			cmd->scsi_sense_reason =
					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
			return PYX_TRANSPORT_LU_COMM_FAILURE;
		}
		cmd->t_task.t_task_cdbs += task_cdbs;

#if 0
		printk(KERN_INFO "data_length: %u, LBA: %llu t_tasks_sectors:"
			" %u, t_task_cdbs: %u\n", obj_ptr, cmd->data_length,
			cmd->t_task.t_task_lba, cmd->t_task.t_tasks_sectors,
			cmd->t_task.t_task_cdbs);
#endif
	}

	atomic_set(&cmd->t_task.t_task_cdbs_left, task_cdbs);
	atomic_set(&cmd->t_task.t_task_cdbs_ex_left, task_cdbs);
	atomic_set(&cmd->t_task.t_task_cdbs_timeout_left, task_cdbs);
	return 0;
}

static int
transport_generic_get_mem(struct se_cmd *cmd, u32 length, u32 dma_size)
{
	unsigned char *buf;
	struct se_mem *se_mem;

	/*
	 * If the device uses memory mapping this is enough.
	 */
	if (cmd->se_dev->transport->do_se_mem_map)
		return 0;

	while (length) {
		se_mem = kmem_cache_zalloc(se_mem_cache, GFP_KERNEL);
		if (!(se_mem)) {
			printk(KERN_ERR "Unable to allocate struct se_mem\n");
			goto out;
		}

/* #warning FIXME Allocate contigous pages for struct se_mem elements */
		se_mem->se_page = alloc_pages(GFP_KERNEL, 0);
		if (!(se_mem->se_page)) {
			printk(KERN_ERR "alloc_pages() failed\n");
			goto out;
		}

		buf = kmap_atomic(se_mem->se_page, KM_IRQ0);
		if (!(buf)) {
			printk(KERN_ERR "kmap_atomic() failed\n");
			goto out;
		}
		INIT_LIST_HEAD(&se_mem->se_list);
		se_mem->se_len = (length > dma_size) ? dma_size : length;
		memset(buf, 0, se_mem->se_len);
		kunmap_atomic(buf, KM_IRQ0);

		list_add_tail(&se_mem->se_list, &cmd->t_task.t_mem_list);
		cmd->t_task.t_tasks_se_num++;

		DEBUG_MEM("Allocated struct se_mem page(%p) Length(%u)"
			" Offset(%u)\n", se_mem->se_page, se_mem->se_len,
			se_mem->se_off);

		length -= se_mem->se_len;
	}

	DEBUG_MEM("Allocated total struct se_mem elements(%u)\n",
			cmd->t_task.t_tasks_se_num);

	return 0;
out:
	if (se_mem)
		__free_pages(se_mem->se_page, 0);
	kmem_cache_free(se_mem_cache, se_mem);
	return -ENOMEM;
}

int transport_init_task_sg(
	struct se_task *task,
	struct se_mem *in_se_mem,
	u32 task_offset)
{
	struct se_cmd *se_cmd = task->task_se_cmd;
	struct se_device *se_dev = se_cmd->se_dev;
	struct se_mem *se_mem = in_se_mem;
	struct target_core_fabric_ops *tfo = se_cmd->se_tfo;
	u32 sg_length, task_size = task->task_size, task_sg_num_padded;

	while (task_size != 0) {
		DEBUG_SC("se_mem->se_page(%p) se_mem->se_len(%u)"
			" se_mem->se_off(%u) task_offset(%u)\n",
			se_mem->se_page, se_mem->se_len,
			se_mem->se_off, task_offset);

		if (task_offset == 0) {
			if (task_size >= se_mem->se_len) {
				sg_length = se_mem->se_len;

				if (!(list_is_last(&se_mem->se_list,
						&se_cmd->t_task.t_mem_list)))
					se_mem = list_entry(se_mem->se_list.next,
							struct se_mem, se_list);
			} else {
				sg_length = task_size;
				task_size -= sg_length;
				goto next;
			}

			DEBUG_SC("sg_length(%u) task_size(%u)\n",
					sg_length, task_size);
		} else {
			if ((se_mem->se_len - task_offset) > task_size) {
				sg_length = task_size;
				task_size -= sg_length;
				goto next;
			 } else {
				sg_length = (se_mem->se_len - task_offset);

				if (!(list_is_last(&se_mem->se_list,
						&se_cmd->t_task.t_mem_list)))
					se_mem = list_entry(se_mem->se_list.next,
							struct se_mem, se_list);
			}

			DEBUG_SC("sg_length(%u) task_size(%u)\n",
					sg_length, task_size);

			task_offset = 0;
		}
		task_size -= sg_length;
next:
		DEBUG_SC("task[%u] - Reducing task_size to(%u)\n",
			task->task_no, task_size);

		task->task_sg_num++;
	}
	/*
	 * Check if the fabric module driver is requesting that all
	 * struct se_task->task_sg[] be chained together..  If so,
	 * then allocate an extra padding SG entry for linking and
	 * marking the end of the chained SGL.
	 */
	if (tfo->task_sg_chaining) {
		task_sg_num_padded = (task->task_sg_num + 1);
		task->task_padded_sg = 1;
	} else
		task_sg_num_padded = task->task_sg_num;

	task->task_sg = kzalloc(task_sg_num_padded *
			sizeof(struct scatterlist), GFP_KERNEL);
	if (!(task->task_sg)) {
		printk(KERN_ERR "Unable to allocate memory for"
				" task->task_sg\n");
		return -ENOMEM;
	}
	sg_init_table(&task->task_sg[0], task_sg_num_padded);
	/*
	 * Setup task->task_sg_bidi for SCSI READ payload for
	 * TCM/pSCSI passthrough if present for BIDI-COMMAND
	 */
	if (!list_empty(&se_cmd->t_task.t_mem_bidi_list) &&
	    (se_dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)) {
		task->task_sg_bidi = kzalloc(task_sg_num_padded *
				sizeof(struct scatterlist), GFP_KERNEL);
		if (!(task->task_sg_bidi)) {
			kfree(task->task_sg);
			task->task_sg = NULL;
			printk(KERN_ERR "Unable to allocate memory for"
				" task->task_sg_bidi\n");
			return -ENOMEM;
		}
		sg_init_table(&task->task_sg_bidi[0], task_sg_num_padded);
	}
	/*
	 * For the chaining case, setup the proper end of SGL for the
	 * initial submission struct task into struct se_subsystem_api.
	 * This will be cleared later by transport_do_task_sg_chain()
	 */
	if (task->task_padded_sg) {
		sg_mark_end(&task->task_sg[task->task_sg_num - 1]);
		/*
		 * Added the 'if' check before marking end of bi-directional
		 * scatterlist (which gets created only in case of request
		 * (RD + WR).
		 */
		if (task->task_sg_bidi)
			sg_mark_end(&task->task_sg_bidi[task->task_sg_num - 1]);
	}

	DEBUG_SC("Successfully allocated task->task_sg_num(%u),"
		" task_sg_num_padded(%u)\n", task->task_sg_num,
		task_sg_num_padded);

	return task->task_sg_num;
}

static inline int transport_set_tasks_sectors_disk(
	struct se_task *task,
	struct se_device *dev,
	unsigned long long lba,
	u32 sectors,
	int *max_sectors_set)
{
	if ((lba + sectors) > transport_dev_end_lba(dev)) {
		task->task_sectors = ((transport_dev_end_lba(dev) - lba) + 1);

		if (task->task_sectors > dev->se_sub_dev->se_dev_attrib.max_sectors) {
			task->task_sectors = dev->se_sub_dev->se_dev_attrib.max_sectors;
			*max_sectors_set = 1;
		}
	} else {
		if (sectors > dev->se_sub_dev->se_dev_attrib.max_sectors) {
			task->task_sectors = dev->se_sub_dev->se_dev_attrib.max_sectors;
			*max_sectors_set = 1;
		} else
			task->task_sectors = sectors;
	}

	return 0;
}

static inline int transport_set_tasks_sectors_non_disk(
	struct se_task *task,
	struct se_device *dev,
	unsigned long long lba,
	u32 sectors,
	int *max_sectors_set)
{
	if (sectors > dev->se_sub_dev->se_dev_attrib.max_sectors) {
		task->task_sectors = dev->se_sub_dev->se_dev_attrib.max_sectors;
		*max_sectors_set = 1;
	} else
		task->task_sectors = sectors;

	return 0;
}

static inline int transport_set_tasks_sectors(
	struct se_task *task,
	struct se_device *dev,
	unsigned long long lba,
	u32 sectors,
	int *max_sectors_set)
{
	return (dev->transport->get_device_type(dev) == TYPE_DISK) ?
		transport_set_tasks_sectors_disk(task, dev, lba, sectors,
				max_sectors_set) :
		transport_set_tasks_sectors_non_disk(task, dev, lba, sectors,
				max_sectors_set);
}

/*
 * Convert a sgl into a linked list of se_mems.
 */
static int transport_map_sg_to_mem(
	struct se_cmd *cmd,
	struct list_head *se_mem_list,
	struct scatterlist *sg,
	u32 *sg_count)
{
	struct se_mem *se_mem;
	u32 cmd_size = cmd->data_length;

	WARN_ON(!sg);

	while (cmd_size) {
		/*
		 * NOTE: it is safe to return -ENOMEM at any time in creating this
		 * list because transport_free_pages() will eventually be called, and is
		 * smart enough to deallocate all list items for sg and sg_bidi lists.
		 */
		se_mem = kmem_cache_zalloc(se_mem_cache, GFP_KERNEL);
		if (!(se_mem)) {
			printk(KERN_ERR "Unable to allocate struct se_mem\n");
			return -ENOMEM;
		}
		INIT_LIST_HEAD(&se_mem->se_list);
		DEBUG_MEM("sg_to_mem: Starting loop with cmd_size: %u"
			" sg_page: %p offset: %d length: %d\n", cmd_size,
			sg_page(sg), sg->offset, sg->length);

		se_mem->se_page = sg_page(sg);
		se_mem->se_off = sg->offset;

		if (cmd_size > sg->length) {
			se_mem->se_len = sg->length;
			sg = sg_next(sg);
		} else
			se_mem->se_len = cmd_size;

		cmd_size -= se_mem->se_len;
		(*sg_count)++;

		DEBUG_MEM("sg_to_mem: sg_count: %u cmd_size: %u\n",
				sg_count, cmd_size);
		DEBUG_MEM("sg_to_mem: Final se_page: %p se_off: %d se_len: %d\n",
				se_mem->se_page, se_mem->se_off, se_mem->se_len);

		list_add_tail(&se_mem->se_list, se_mem_list);
	}

	DEBUG_MEM("task[0] - Mapped(%u) struct scatterlist segments\n", sg_count);

	return 0;
}

/*	transport_map_mem_to_sg():
 *
 *
 */
int transport_map_mem_to_sg(
	struct se_task *task,
	struct list_head *se_mem_list,
	void *in_mem,
	struct se_mem *in_se_mem,
	struct se_mem **out_se_mem,
	u32 *se_mem_cnt,
	u32 *task_offset)
{
	struct se_cmd *se_cmd = task->task_se_cmd;
	struct se_mem *se_mem = in_se_mem;
	struct scatterlist *sg = (struct scatterlist *)in_mem;
	u32 task_size = task->task_size, sg_no = 0;

	if (!sg) {
		printk(KERN_ERR "Unable to locate valid struct"
				" scatterlist pointer\n");
		return -EINVAL;
	}

	while (task_size != 0) {
		/*
		 * Setup the contigious array of scatterlists for
		 * this struct se_task.
		 */
		sg_assign_page(sg, se_mem->se_page);

		if (*task_offset == 0) {
			sg->offset = se_mem->se_off;

			if (task_size >= se_mem->se_len) {
				sg->length = se_mem->se_len;

				if (!(list_is_last(&se_mem->se_list,
						&se_cmd->t_task.t_mem_list))) {
					se_mem = list_entry(se_mem->se_list.next,
							struct se_mem, se_list);
					(*se_mem_cnt)++;
				}
			} else {
				sg->length = task_size;
				/*
				 * Determine if we need to calculate an offset
				 * into the struct se_mem on the next go around..
				 */
				task_size -= sg->length;
				if (!(task_size))
					*task_offset = sg->length;

				goto next;
			}

		} else {
			sg->offset = (*task_offset + se_mem->se_off);

			if ((se_mem->se_len - *task_offset) > task_size) {
				sg->length = task_size;
				/*
				 * Determine if we need to calculate an offset
				 * into the struct se_mem on the next go around..
				 */
				task_size -= sg->length;
				if (!(task_size))
					*task_offset += sg->length;

				goto next;
			} else {
				sg->length = (se_mem->se_len - *task_offset);

				if (!(list_is_last(&se_mem->se_list,
						&se_cmd->t_task.t_mem_list))) {
					se_mem = list_entry(se_mem->se_list.next,
							struct se_mem, se_list);
					(*se_mem_cnt)++;
				}
			}

			*task_offset = 0;
		}
		task_size -= sg->length;
next:
		DEBUG_MEM("task[%u] mem_to_sg - sg[%u](%p)(%u)(%u) - Reducing"
			" task_size to(%u), task_offset: %u\n", task->task_no, sg_no,
			sg_page(sg), sg->length, sg->offset, task_size, *task_offset);

		sg_no++;
		if (!(task_size))
			break;

		sg = sg_next(sg);

		if (task_size > se_cmd->data_length)
			BUG();
	}
	*out_se_mem = se_mem;

	DEBUG_MEM("task[%u] - Mapped(%u) struct se_mem segments to total(%u)"
		" SGs\n", task->task_no, *se_mem_cnt, sg_no);

	return 0;
}

/*
 * This function can be used by HW target mode drivers to create a linked
 * scatterlist from all contiguously allocated struct se_task->task_sg[].
 * This is intended to be called during the completion path by TCM Core
 * when struct target_core_fabric_ops->check_task_sg_chaining is enabled.
 */
void transport_do_task_sg_chain(struct se_cmd *cmd)
{
	struct scatterlist *sg_head = NULL, *sg_link = NULL, *sg_first = NULL;
	struct scatterlist *sg_head_cur = NULL, *sg_link_cur = NULL;
	struct scatterlist *sg, *sg_end = NULL, *sg_end_cur = NULL;
	struct se_task *task;
	struct target_core_fabric_ops *tfo = cmd->se_tfo;
	u32 task_sg_num = 0, sg_count = 0;
	int i;

	if (tfo->task_sg_chaining == 0) {
		printk(KERN_ERR "task_sg_chaining is diabled for fabric module:"
				" %s\n", tfo->get_fabric_name());
		dump_stack();
		return;
	}
	/*
	 * Walk the struct se_task list and setup scatterlist chains
	 * for each contiguosly allocated struct se_task->task_sg[].
	 */
	list_for_each_entry(task, &cmd->t_task.t_task_list, t_list) {
		if (!(task->task_sg) || !(task->task_padded_sg))
			continue;

		if (sg_head && sg_link) {
			sg_head_cur = &task->task_sg[0];
			sg_link_cur = &task->task_sg[task->task_sg_num];
			/*
			 * Either add chain or mark end of scatterlist
			 */
			if (!(list_is_last(&task->t_list,
					&cmd->t_task.t_task_list))) {
				/*
				 * Clear existing SGL termination bit set in
				 * transport_init_task_sg(), see sg_mark_end()
				 */
				sg_end_cur = &task->task_sg[task->task_sg_num - 1];
				sg_end_cur->page_link &= ~0x02;

				sg_chain(sg_head, task_sg_num, sg_head_cur);
				sg_count += task->task_sg_num;
				task_sg_num = (task->task_sg_num + 1);
			} else {
				sg_chain(sg_head, task_sg_num, sg_head_cur);
				sg_count += task->task_sg_num;
				task_sg_num = task->task_sg_num;
			}

			sg_head = sg_head_cur;
			sg_link = sg_link_cur;
			continue;
		}
		sg_head = sg_first = &task->task_sg[0];
		sg_link = &task->task_sg[task->task_sg_num];
		/*
		 * Check for single task..
		 */
		if (!(list_is_last(&task->t_list, &cmd->t_task.t_task_list))) {
			/*
			 * Clear existing SGL termination bit set in
			 * transport_init_task_sg(), see sg_mark_end()
			 */
			sg_end = &task->task_sg[task->task_sg_num - 1];
			sg_end->page_link &= ~0x02;
			sg_count += task->task_sg_num;
			task_sg_num = (task->task_sg_num + 1);
		} else {
			sg_count += task->task_sg_num;
			task_sg_num = task->task_sg_num;
		}
	}
	/*
	 * Setup the starting pointer and total t_tasks_sg_linked_no including
	 * padding SGs for linking and to mark the end.
	 */
	cmd->t_task.t_tasks_sg_chained = sg_first;
	cmd->t_task.t_tasks_sg_chained_no = sg_count;

	DEBUG_CMD_M("Setup cmd: %p cmd->t_task.t_tasks_sg_chained: %p and"
		" t_tasks_sg_chained_no: %u\n", cmd, cmd->t_task.t_tasks_sg_chained,
		cmd->t_task.t_tasks_sg_chained_no);

	for_each_sg(cmd->t_task.t_tasks_sg_chained, sg,
			cmd->t_task.t_tasks_sg_chained_no, i) {

		DEBUG_CMD_M("SG[%d]: %p page: %p length: %d offset: %d\n",
			i, sg, sg_page(sg), sg->length, sg->offset);
		if (sg_is_chain(sg))
			DEBUG_CMD_M("SG: %p sg_is_chain=1\n", sg);
		if (sg_is_last(sg))
			DEBUG_CMD_M("SG: %p sg_is_last=1\n", sg);
	}
}
EXPORT_SYMBOL(transport_do_task_sg_chain);

static int transport_do_se_mem_map(
	struct se_device *dev,
	struct se_task *task,
	struct list_head *se_mem_list,
	void *in_mem,
	struct se_mem *in_se_mem,
	struct se_mem **out_se_mem,
	u32 *se_mem_cnt,
	u32 *task_offset_in)
{
	u32 task_offset = *task_offset_in;
	int ret = 0;
	/*
	 * se_subsystem_api_t->do_se_mem_map is used when internal allocation
	 * has been done by the transport plugin.
	 */
	if (dev->transport->do_se_mem_map) {
		ret = dev->transport->do_se_mem_map(task, se_mem_list,
				in_mem, in_se_mem, out_se_mem, se_mem_cnt,
				task_offset_in);
		if (ret == 0)
			task->task_se_cmd->t_task.t_tasks_se_num += *se_mem_cnt;

		return ret;
	}

	BUG_ON(list_empty(se_mem_list));
	/*
	 * This is the normal path for all normal non BIDI and BIDI-COMMAND
	 * WRITE payloads..  If we need to do BIDI READ passthrough for
	 * TCM/pSCSI the first call to transport_do_se_mem_map ->
	 * transport_init_task_sg() -> transport_map_mem_to_sg() will do the
	 * allocation for task->task_sg_bidi, and the subsequent call to
	 * transport_do_se_mem_map() from transport_generic_get_cdb_count()
	 */
	if (!(task->task_sg_bidi)) {
		/*
		 * Assume default that transport plugin speaks preallocated
		 * scatterlists.
		 */
		ret = transport_init_task_sg(task, in_se_mem, task_offset);
		if (ret <= 0)
			return ret;
		/*
		 * struct se_task->task_sg now contains the struct scatterlist array.
		 */
		return transport_map_mem_to_sg(task, se_mem_list, task->task_sg,
					in_se_mem, out_se_mem, se_mem_cnt,
					task_offset_in);
	}
	/*
	 * Handle the se_mem_list -> struct task->task_sg_bidi
	 * memory map for the extra BIDI READ payload
	 */
	return transport_map_mem_to_sg(task, se_mem_list, task->task_sg_bidi,
				in_se_mem, out_se_mem, se_mem_cnt,
				task_offset_in);
}

static u32 transport_generic_get_cdb_count(
	struct se_cmd *cmd,
	unsigned long long lba,
	u32 sectors,
	enum dma_data_direction data_direction,
	struct list_head *mem_list,
	int set_counts)
{
	unsigned char *cdb = NULL;
	struct se_task *task;
	struct se_mem *se_mem = NULL, *se_mem_lout = NULL;
	struct se_mem *se_mem_bidi = NULL, *se_mem_bidi_lout = NULL;
	struct se_device *dev = cmd->se_dev;
	int max_sectors_set = 0, ret;
	u32 task_offset_in = 0, se_mem_cnt = 0, se_mem_bidi_cnt = 0, task_cdbs = 0;

	if (!mem_list) {
		printk(KERN_ERR "mem_list is NULL in transport_generic_get"
				"_cdb_count()\n");
		return 0;
	}
	/*
	 * While using RAMDISK_DR backstores is the only case where
	 * mem_list will ever be empty at this point.
	 */
	if (!(list_empty(mem_list)))
		se_mem = list_first_entry(mem_list, struct se_mem, se_list);
	/*
	 * Check for extra se_mem_bidi mapping for BIDI-COMMANDs to
	 * struct se_task->task_sg_bidi for TCM/pSCSI passthrough operation
	 */
	if (!list_empty(&cmd->t_task.t_mem_bidi_list) &&
	    (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV))
		se_mem_bidi = list_first_entry(&cmd->t_task.t_mem_bidi_list,
					struct se_mem, se_list);

	while (sectors) {
		DEBUG_VOL("ITT[0x%08x] LBA(%llu) SectorsLeft(%u) EOBJ(%llu)\n",
			cmd->se_tfo->get_task_tag(cmd), lba, sectors,
			transport_dev_end_lba(dev));

		task = transport_generic_get_task(cmd, data_direction);
		if (!(task))
			goto out;

		transport_set_tasks_sectors(task, dev, lba, sectors,
				&max_sectors_set);

		task->task_lba = lba;
		lba += task->task_sectors;
		sectors -= task->task_sectors;
		task->task_size = (task->task_sectors *
				   dev->se_sub_dev->se_dev_attrib.block_size);

		cdb = dev->transport->get_cdb(task);
		if ((cdb)) {
			memcpy(cdb, cmd->t_task.t_task_cdb,
				scsi_command_size(cmd->t_task.t_task_cdb));
			cmd->transport_split_cdb(task->task_lba,
					&task->task_sectors, cdb);
		}

		/*
		 * Perform the SE OBJ plugin and/or Transport plugin specific
		 * mapping for cmd->t_task.t_mem_list. And setup the
		 * task->task_sg and if necessary task->task_sg_bidi
		 */
		ret = transport_do_se_mem_map(dev, task, mem_list,
				NULL, se_mem, &se_mem_lout, &se_mem_cnt,
				&task_offset_in);
		if (ret < 0)
			goto out;

		se_mem = se_mem_lout;
		/*
		 * Setup the cmd->t_task.t_mem_bidi_list -> task->task_sg_bidi
		 * mapping for SCSI READ for BIDI-COMMAND passthrough with TCM/pSCSI
		 *
		 * Note that the first call to transport_do_se_mem_map() above will
		 * allocate struct se_task->task_sg_bidi in transport_do_se_mem_map()
		 * -> transport_init_task_sg(), and the second here will do the
		 * mapping for SCSI READ for BIDI-COMMAND passthrough with TCM/pSCSI.
		 */
		if (task->task_sg_bidi != NULL) {
			ret = transport_do_se_mem_map(dev, task,
				&cmd->t_task.t_mem_bidi_list, NULL,
				se_mem_bidi, &se_mem_bidi_lout, &se_mem_bidi_cnt,
				&task_offset_in);
			if (ret < 0)
				goto out;

			se_mem_bidi = se_mem_bidi_lout;
		}
		task_cdbs++;

		DEBUG_VOL("Incremented task_cdbs(%u) task->task_sg_num(%u)\n",
				task_cdbs, task->task_sg_num);

		if (max_sectors_set) {
			max_sectors_set = 0;
			continue;
		}

		if (!sectors)
			break;
	}

	if (set_counts) {
		atomic_inc(&cmd->t_task.t_fe_count);
		atomic_inc(&cmd->t_task.t_se_count);
	}

	DEBUG_VOL("ITT[0x%08x] total %s cdbs(%u)\n",
		cmd->se_tfo->get_task_tag(cmd), (data_direction == DMA_TO_DEVICE)
		? "DMA_TO_DEVICE" : "DMA_FROM_DEVICE", task_cdbs);

	return task_cdbs;
out:
	return 0;
}

static int
transport_map_control_cmd_to_task(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	unsigned char *cdb;
	struct se_task *task;
	int ret;

	task = transport_generic_get_task(cmd, cmd->data_direction);
	if (!task)
		return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;

	cdb = dev->transport->get_cdb(task);
	if (cdb)
		memcpy(cdb, cmd->t_task.t_task_cdb,
			scsi_command_size(cmd->t_task.t_task_cdb));

	task->task_size = cmd->data_length;
	task->task_sg_num =
		(cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB) ? 1 : 0;

	atomic_inc(&cmd->t_task.t_fe_count);
	atomic_inc(&cmd->t_task.t_se_count);

	if (cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB) {
		struct se_mem *se_mem = NULL, *se_mem_lout = NULL;
		u32 se_mem_cnt = 0, task_offset = 0;

		if (!list_empty(&cmd->t_task.t_mem_list))
			se_mem = list_first_entry(&cmd->t_task.t_mem_list,
					struct se_mem, se_list);

		ret = transport_do_se_mem_map(dev, task,
				&cmd->t_task.t_mem_list, NULL, se_mem,
				&se_mem_lout, &se_mem_cnt, &task_offset);
		if (ret < 0)
			return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;

		if (dev->transport->map_task_SG)
			return dev->transport->map_task_SG(task);
		return 0;
	} else if (cmd->se_cmd_flags & SCF_SCSI_CONTROL_NONSG_IO_CDB) {
		if (dev->transport->map_task_non_SG)
			return dev->transport->map_task_non_SG(task);
		return 0;
	} else if (cmd->se_cmd_flags & SCF_SCSI_NON_DATA_CDB) {
		if (dev->transport->cdb_none)
			return dev->transport->cdb_none(task);
		return 0;
	} else {
		BUG();
		return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
	}
}

/*	 transport_generic_new_cmd(): Called from transport_processing_thread()
 *
 *	 Allocate storage transport resources from a set of values predefined
 *	 by transport_generic_cmd_sequencer() from the iSCSI Target RX process.
 *	 Any non zero return here is treated as an "out of resource' op here.
 */
	/*
	 * Generate struct se_task(s) and/or their payloads for this CDB.
	 */
static int transport_generic_new_cmd(struct se_cmd *cmd)
{
	struct se_portal_group *se_tpg;
	struct se_task *task;
	struct se_device *dev = cmd->se_dev;
	int ret = 0;

	/*
	 * Determine is the TCM fabric module has already allocated physical
	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
	 * to setup beforehand the linked list of physical memory at
	 * cmd->t_task.t_mem_list of struct se_mem->se_page
	 */
	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)) {
		ret = transport_allocate_resources(cmd);
		if (ret < 0)
			return ret;
	}

	ret = transport_get_sectors(cmd);
	if (ret < 0)
		return ret;

	ret = transport_new_cmd_obj(cmd);
	if (ret < 0)
		return ret;

	/*
	 * Determine if the calling TCM fabric module is talking to
	 * Linux/NET via kernel sockets and needs to allocate a
	 * struct iovec array to complete the struct se_cmd
	 */
	se_tpg = cmd->se_lun->lun_sep->sep_tpg;
	if (se_tpg->se_tpg_tfo->alloc_cmd_iovecs != NULL) {
		ret = se_tpg->se_tpg_tfo->alloc_cmd_iovecs(cmd);
		if (ret < 0)
			return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
	}

	if (cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
		list_for_each_entry(task, &cmd->t_task.t_task_list, t_list) {
			if (atomic_read(&task->task_sent))
				continue;
			if (!dev->transport->map_task_SG)
				continue;

			ret = dev->transport->map_task_SG(task);
			if (ret < 0)
				return ret;
		}
	} else {
		ret = transport_map_control_cmd_to_task(cmd);
		if (ret < 0)
			return ret;
	}

	/*
	 * For WRITEs, let the iSCSI Target RX Thread know its buffer is ready..
	 * This WRITE struct se_cmd (and all of its associated struct se_task's)
	 * will be added to the struct se_device execution queue after its WRITE
	 * data has arrived. (ie: It gets handled by the transport processing
	 * thread a second time)
	 */
	if (cmd->data_direction == DMA_TO_DEVICE) {
		transport_add_tasks_to_state_queue(cmd);
		return transport_generic_write_pending(cmd);
	}
	/*
	 * Everything else but a WRITE, add the struct se_cmd's struct se_task's
	 * to the execution queue.
	 */
	transport_execute_tasks(cmd);
	return 0;
}

/*	transport_generic_process_write():
 *
 *
 */
void transport_generic_process_write(struct se_cmd *cmd)
{
#if 0
	/*
	 * Copy SCSI Presented DTL sector(s) from received buffers allocated to
	 * original EDTL
	 */
	if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
		if (!cmd->t_task.t_tasks_se_num) {
			unsigned char *dst, *buf =
				(unsigned char *)cmd->t_task.t_task_buf;

			dst = kzalloc(cmd->cmd_spdtl), GFP_KERNEL);
			if (!(dst)) {
				printk(KERN_ERR "Unable to allocate memory for"
						" WRITE underflow\n");
				transport_generic_request_failure(cmd, NULL,
					PYX_TRANSPORT_REQ_TOO_MANY_SECTORS, 1);
				return;
			}
			memcpy(dst, buf, cmd->cmd_spdtl);

			kfree(cmd->t_task.t_task_buf);
			cmd->t_task.t_task_buf = dst;
		} else {
			struct scatterlist *sg =
				(struct scatterlist *sg)cmd->t_task.t_task_buf;
			struct scatterlist *orig_sg;

			orig_sg = kzalloc(sizeof(struct scatterlist) *
					cmd->t_task.t_tasks_se_num,
					GFP_KERNEL))) {
			if (!(orig_sg)) {
				printk(KERN_ERR "Unable to allocate memory"
						" for WRITE underflow\n");
				transport_generic_request_failure(cmd, NULL,
					PYX_TRANSPORT_REQ_TOO_MANY_SECTORS, 1);
				return;
			}

			memcpy(orig_sg, cmd->t_task.t_task_buf,
					sizeof(struct scatterlist) *
					cmd->t_task.t_tasks_se_num);

			cmd->data_length = cmd->cmd_spdtl;
			/*
			 * FIXME, clear out original struct se_task and state
			 * information.
			 */
			if (transport_generic_new_cmd(cmd) < 0) {
				transport_generic_request_failure(cmd, NULL,
					PYX_TRANSPORT_REQ_TOO_MANY_SECTORS, 1);
				kfree(orig_sg);
				return;
			}

			transport_memcpy_write_sg(cmd, orig_sg);
		}
	}
#endif
	transport_execute_tasks(cmd);
}
EXPORT_SYMBOL(transport_generic_process_write);

/*	transport_generic_write_pending():
 *
 *
 */
static int transport_generic_write_pending(struct se_cmd *cmd)
{
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	cmd->t_state = TRANSPORT_WRITE_PENDING;
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
	/*
	 * For the TCM control CDBs using a contiguous buffer, do the memcpy
	 * from the passed Linux/SCSI struct scatterlist located at
	 * se_cmd->t_task.t_task_pt_buf to the contiguous buffer at
	 * se_cmd->t_task.t_task_buf.
	 */
	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_CONTIG_TO_SG)
		transport_memcpy_read_contig(cmd,
				cmd->t_task.t_task_buf,
				cmd->t_task.t_task_pt_sgl);
	/*
	 * Clear the se_cmd for WRITE_PENDING status in order to set
	 * cmd->t_task.t_transport_active=0 so that transport_generic_handle_data
	 * can be called from HW target mode interrupt code.  This is safe
	 * to be called with transport_off=1 before the cmd->se_tfo->write_pending
	 * because the se_cmd->se_lun pointer is not being cleared.
	 */
	transport_cmd_check_stop(cmd, 1, 0);

	/*
	 * Call the fabric write_pending function here to let the
	 * frontend know that WRITE buffers are ready.
	 */
	ret = cmd->se_tfo->write_pending(cmd);
	if (ret < 0)
		return ret;

	return PYX_TRANSPORT_WRITE_PENDING;
}

/*	transport_release_cmd_to_pool():
 *
 *
 */
void transport_release_cmd_to_pool(struct se_cmd *cmd)
{
	BUG_ON(!cmd->se_tfo);

	transport_free_se_cmd(cmd);
	cmd->se_tfo->release_cmd_to_pool(cmd);
}
EXPORT_SYMBOL(transport_release_cmd_to_pool);

/*	transport_generic_free_cmd():
 *
 *	Called from processing frontend to release storage engine resources
 */
void transport_generic_free_cmd(
	struct se_cmd *cmd,
	int wait_for_tasks,
	int release_to_pool,
	int session_reinstatement)
{
	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD))
		transport_release_cmd_to_pool(cmd);
	else {
		core_dec_lacl_count(cmd->se_sess->se_node_acl, cmd);

		if (cmd->se_lun) {
#if 0
			printk(KERN_INFO "cmd: %p ITT: 0x%08x contains"
				" cmd->se_lun\n", cmd,
				cmd->se_tfo->get_task_tag(cmd));
#endif
			transport_lun_remove_cmd(cmd);
		}

		if (wait_for_tasks && cmd->transport_wait_for_tasks)
			cmd->transport_wait_for_tasks(cmd, 0, 0);

		transport_free_dev_tasks(cmd);

		transport_generic_remove(cmd, release_to_pool,
				session_reinstatement);
	}
}
EXPORT_SYMBOL(transport_generic_free_cmd);

static void transport_nop_wait_for_tasks(
	struct se_cmd *cmd,
	int remove_cmd,
	int session_reinstatement)
{
	return;
}

/*	transport_lun_wait_for_tasks():
 *
 *	Called from ConfigFS context to stop the passed struct se_cmd to allow
 *	an struct se_lun to be successfully shutdown.
 */
static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
{
	unsigned long flags;
	int ret;
	/*
	 * If the frontend has already requested this struct se_cmd to
	 * be stopped, we can safely ignore this struct se_cmd.
	 */
	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	if (atomic_read(&cmd->t_task.t_transport_stop)) {
		atomic_set(&cmd->t_task.transport_lun_stop, 0);
		DEBUG_TRANSPORT_S("ConfigFS ITT[0x%08x] - t_transport_stop =="
			" TRUE, skipping\n", cmd->se_tfo->get_task_tag(cmd));
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		transport_cmd_check_stop(cmd, 1, 0);
		return -EPERM;
	}
	atomic_set(&cmd->t_task.transport_lun_fe_stop, 1);
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

	wake_up_interruptible(&cmd->se_dev->dev_queue_obj.thread_wq);

	ret = transport_stop_tasks_for_cmd(cmd);

	DEBUG_TRANSPORT_S("ConfigFS: cmd: %p t_task_cdbs: %d stop tasks ret:"
			" %d\n", cmd, cmd->t_task.t_task_cdbs, ret);
	if (!ret) {
		DEBUG_TRANSPORT_S("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
				cmd->se_tfo->get_task_tag(cmd));
		wait_for_completion(&cmd->t_task.transport_lun_stop_comp);
		DEBUG_TRANSPORT_S("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
				cmd->se_tfo->get_task_tag(cmd));
	}
	transport_remove_cmd_from_queue(cmd, &cmd->se_dev->dev_queue_obj);

	return 0;
}

/* #define DEBUG_CLEAR_LUN */
#ifdef DEBUG_CLEAR_LUN
#define DEBUG_CLEAR_L(x...) printk(KERN_INFO x)
#else
#define DEBUG_CLEAR_L(x...)
#endif

static void __transport_clear_lun_from_sessions(struct se_lun *lun)
{
	struct se_cmd *cmd = NULL;
	unsigned long lun_flags, cmd_flags;
	/*
	 * Do exception processing and return CHECK_CONDITION status to the
	 * Initiator Port.
	 */
	spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
	while (!list_empty(&lun->lun_cmd_list)) {
		cmd = list_first_entry(&lun->lun_cmd_list,
		       struct se_cmd, se_lun_node);
		list_del(&cmd->se_lun_node);

		atomic_set(&cmd->t_task.transport_lun_active, 0);
		/*
		 * This will notify iscsi_target_transport.c:
		 * transport_cmd_check_stop() that a LUN shutdown is in
		 * progress for the iscsi_cmd_t.
		 */
		spin_lock(&cmd->t_task.t_state_lock);
		DEBUG_CLEAR_L("SE_LUN[%d] - Setting cmd->t_task.transport"
			"_lun_stop for  ITT: 0x%08x\n",
			cmd->se_lun->unpacked_lun,
			cmd->se_tfo->get_task_tag(cmd));
		atomic_set(&cmd->t_task.transport_lun_stop, 1);
		spin_unlock(&cmd->t_task.t_state_lock);

		spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);

		if (!(cmd->se_lun)) {
			printk(KERN_ERR "ITT: 0x%08x, [i,t]_state: %u/%u\n",
				cmd->se_tfo->get_task_tag(cmd),
				cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
			BUG();
		}
		/*
		 * If the Storage engine still owns the iscsi_cmd_t, determine
		 * and/or stop its context.
		 */
		DEBUG_CLEAR_L("SE_LUN[%d] - ITT: 0x%08x before transport"
			"_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
			cmd->se_tfo->get_task_tag(cmd));

		if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
			continue;
		}

		DEBUG_CLEAR_L("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
			"_wait_for_tasks(): SUCCESS\n",
			cmd->se_lun->unpacked_lun,
			cmd->se_tfo->get_task_tag(cmd));

		spin_lock_irqsave(&cmd->t_task.t_state_lock, cmd_flags);
		if (!(atomic_read(&cmd->t_task.transport_dev_active))) {
			spin_unlock_irqrestore(&cmd->t_task.t_state_lock, cmd_flags);
			goto check_cond;
		}
		atomic_set(&cmd->t_task.transport_dev_active, 0);
		transport_all_task_dev_remove_state(cmd);
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, cmd_flags);

		transport_free_dev_tasks(cmd);
		/*
		 * The Storage engine stopped this struct se_cmd before it was
		 * send to the fabric frontend for delivery back to the
		 * Initiator Node.  Return this SCSI CDB back with an
		 * CHECK_CONDITION status.
		 */
check_cond:
		transport_send_check_condition_and_sense(cmd,
				TCM_NON_EXISTENT_LUN, 0);
		/*
		 *  If the fabric frontend is waiting for this iscsi_cmd_t to
		 * be released, notify the waiting thread now that LU has
		 * finished accessing it.
		 */
		spin_lock_irqsave(&cmd->t_task.t_state_lock, cmd_flags);
		if (atomic_read(&cmd->t_task.transport_lun_fe_stop)) {
			DEBUG_CLEAR_L("SE_LUN[%d] - Detected FE stop for"
				" struct se_cmd: %p ITT: 0x%08x\n",
				lun->unpacked_lun,
				cmd, cmd->se_tfo->get_task_tag(cmd));

			spin_unlock_irqrestore(&cmd->t_task.t_state_lock,
					cmd_flags);
			transport_cmd_check_stop(cmd, 1, 0);
			complete(&cmd->t_task.transport_lun_fe_stop_comp);
			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
			continue;
		}
		DEBUG_CLEAR_L("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
			lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));

		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, cmd_flags);
		spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
	}
	spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
}

static int transport_clear_lun_thread(void *p)
{
	struct se_lun *lun = (struct se_lun *)p;

	__transport_clear_lun_from_sessions(lun);
	complete(&lun->lun_shutdown_comp);

	return 0;
}

int transport_clear_lun_from_sessions(struct se_lun *lun)
{
	struct task_struct *kt;

	kt = kthread_run(transport_clear_lun_thread, lun,
			"tcm_cl_%u", lun->unpacked_lun);
	if (IS_ERR(kt)) {
		printk(KERN_ERR "Unable to start clear_lun thread\n");
		return PTR_ERR(kt);
	}
	wait_for_completion(&lun->lun_shutdown_comp);

	return 0;
}

/*	transport_generic_wait_for_tasks():
 *
 *	Called from frontend or passthrough context to wait for storage engine
 *	to pause and/or release frontend generated struct se_cmd.
 */
static void transport_generic_wait_for_tasks(
	struct se_cmd *cmd,
	int remove_cmd,
	int session_reinstatement)
{
	unsigned long flags;

	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) && !(cmd->se_tmr_req))
		return;

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	/*
	 * If we are already stopped due to an external event (ie: LUN shutdown)
	 * sleep until the connection can have the passed struct se_cmd back.
	 * The cmd->t_task.transport_lun_stopped_sem will be upped by
	 * transport_clear_lun_from_sessions() once the ConfigFS context caller
	 * has completed its operation on the struct se_cmd.
	 */
	if (atomic_read(&cmd->t_task.transport_lun_stop)) {

		DEBUG_TRANSPORT_S("wait_for_tasks: Stopping"
			" wait_for_completion(&cmd->t_tasktransport_lun_fe"
			"_stop_comp); for ITT: 0x%08x\n",
			cmd->se_tfo->get_task_tag(cmd));
		/*
		 * There is a special case for WRITES where a FE exception +
		 * LUN shutdown means ConfigFS context is still sleeping on
		 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
		 * We go ahead and up transport_lun_stop_comp just to be sure
		 * here.
		 */
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		complete(&cmd->t_task.transport_lun_stop_comp);
		wait_for_completion(&cmd->t_task.transport_lun_fe_stop_comp);
		spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);

		transport_all_task_dev_remove_state(cmd);
		/*
		 * At this point, the frontend who was the originator of this
		 * struct se_cmd, now owns the structure and can be released through
		 * normal means below.
		 */
		DEBUG_TRANSPORT_S("wait_for_tasks: Stopped"
			" wait_for_completion(&cmd->t_tasktransport_lun_fe_"
			"stop_comp); for ITT: 0x%08x\n",
			cmd->se_tfo->get_task_tag(cmd));

		atomic_set(&cmd->t_task.transport_lun_stop, 0);
	}
	if (!atomic_read(&cmd->t_task.t_transport_active) ||
	     atomic_read(&cmd->t_task.t_transport_aborted))
		goto remove;

	atomic_set(&cmd->t_task.t_transport_stop, 1);

	DEBUG_TRANSPORT_S("wait_for_tasks: Stopping %p ITT: 0x%08x"
		" i_state: %d, t_state/def_t_state: %d/%d, t_transport_stop"
		" = TRUE\n", cmd, cmd->se_tfo->get_task_tag(cmd),
		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state,
		cmd->deferred_t_state);

	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

	wake_up_interruptible(&cmd->se_dev->dev_queue_obj.thread_wq);

	wait_for_completion(&cmd->t_task.t_transport_stop_comp);

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	atomic_set(&cmd->t_task.t_transport_active, 0);
	atomic_set(&cmd->t_task.t_transport_stop, 0);

	DEBUG_TRANSPORT_S("wait_for_tasks: Stopped wait_for_compltion("
		"&cmd->t_task.t_transport_stop_comp) for ITT: 0x%08x\n",
		cmd->se_tfo->get_task_tag(cmd));
remove:
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
	if (!remove_cmd)
		return;

	transport_generic_free_cmd(cmd, 0, 0, session_reinstatement);
}

static int transport_get_sense_codes(
	struct se_cmd *cmd,
	u8 *asc,
	u8 *ascq)
{
	*asc = cmd->scsi_asc;
	*ascq = cmd->scsi_ascq;

	return 0;
}

static int transport_set_sense_codes(
	struct se_cmd *cmd,
	u8 asc,
	u8 ascq)
{
	cmd->scsi_asc = asc;
	cmd->scsi_ascq = ascq;

	return 0;
}

int transport_send_check_condition_and_sense(
	struct se_cmd *cmd,
	u8 reason,
	int from_transport)
{
	unsigned char *buffer = cmd->sense_buffer;
	unsigned long flags;
	int offset;
	u8 asc = 0, ascq = 0;

	spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
		spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);
		return 0;
	}
	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
	spin_unlock_irqrestore(&cmd->t_task.t_state_lock, flags);

	if (!reason && from_transport)
		goto after_reason;

	if (!from_transport)
		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
	/*
	 * Data Segment and SenseLength of the fabric response PDU.
	 *
	 * TRANSPORT_SENSE_BUFFER is now set to SCSI_SENSE_BUFFERSIZE
	 * from include/scsi/scsi_cmnd.h
	 */
	offset = cmd->se_tfo->set_fabric_sense_len(cmd,
				TRANSPORT_SENSE_BUFFER);
	/*
	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
	 * SENSE KEY values from include/scsi/scsi.h
	 */
	switch (reason) {
	case TCM_NON_EXISTENT_LUN:
	case TCM_UNSUPPORTED_SCSI_OPCODE:
	case TCM_SECTOR_COUNT_TOO_MANY:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ILLEGAL REQUEST */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
		/* INVALID COMMAND OPERATION CODE */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x20;
		break;
	case TCM_UNKNOWN_MODE_PAGE:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ILLEGAL REQUEST */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
		/* INVALID FIELD IN CDB */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x24;
		break;
	case TCM_CHECK_CONDITION_ABORT_CMD:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ABORTED COMMAND */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
		/* BUS DEVICE RESET FUNCTION OCCURRED */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x29;
		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x03;
		break;
	case TCM_INCORRECT_AMOUNT_OF_DATA:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ABORTED COMMAND */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
		/* WRITE ERROR */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x0c;
		/* NOT ENOUGH UNSOLICITED DATA */
		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x0d;
		break;
	case TCM_INVALID_CDB_FIELD:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ABORTED COMMAND */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
		/* INVALID FIELD IN CDB */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x24;
		break;
	case TCM_INVALID_PARAMETER_LIST:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ABORTED COMMAND */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
		/* INVALID FIELD IN PARAMETER LIST */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x26;
		break;
	case TCM_UNEXPECTED_UNSOLICITED_DATA:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ABORTED COMMAND */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
		/* WRITE ERROR */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x0c;
		/* UNEXPECTED_UNSOLICITED_DATA */
		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x0c;
		break;
	case TCM_SERVICE_CRC_ERROR:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ABORTED COMMAND */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
		/* PROTOCOL SERVICE CRC ERROR */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x47;
		/* N/A */
		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x05;
		break;
	case TCM_SNACK_REJECTED:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ABORTED COMMAND */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
		/* READ ERROR */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x11;
		/* FAILED RETRANSMISSION REQUEST */
		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x13;
		break;
	case TCM_WRITE_PROTECTED:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* DATA PROTECT */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
		/* WRITE PROTECTED */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x27;
		break;
	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* UNIT ATTENTION */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
		buffer[offset+SPC_ASC_KEY_OFFSET] = asc;
		buffer[offset+SPC_ASCQ_KEY_OFFSET] = ascq;
		break;
	case TCM_CHECK_CONDITION_NOT_READY:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* Not Ready */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = NOT_READY;
		transport_get_sense_codes(cmd, &asc, &ascq);
		buffer[offset+SPC_ASC_KEY_OFFSET] = asc;
		buffer[offset+SPC_ASCQ_KEY_OFFSET] = ascq;
		break;
	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
	default:
		/* CURRENT ERROR */
		buffer[offset] = 0x70;
		/* ILLEGAL REQUEST */
		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
		/* LOGICAL UNIT COMMUNICATION FAILURE */
		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x80;
		break;
	}
	/*
	 * This code uses linux/include/scsi/scsi.h SAM status codes!
	 */
	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
	/*
	 * Automatically padded, this value is encoded in the fabric's
	 * data_length response PDU containing the SCSI defined sense data.
	 */
	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER + offset;

after_reason:
	cmd->se_tfo->queue_status(cmd);
	return 0;
}
EXPORT_SYMBOL(transport_send_check_condition_and_sense);

int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
{
	int ret = 0;

	if (atomic_read(&cmd->t_task.t_transport_aborted) != 0) {
		if (!(send_status) ||
		     (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
			return 1;
#if 0
		printk(KERN_INFO "Sending delayed SAM_STAT_TASK_ABORTED"
			" status for CDB: 0x%02x ITT: 0x%08x\n",
			cmd->t_task.t_task_cdb[0],
			cmd->se_tfo->get_task_tag(cmd));
#endif
		cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
		cmd->se_tfo->queue_status(cmd);
		ret = 1;
	}
	return ret;
}
EXPORT_SYMBOL(transport_check_aborted_status);

void transport_send_task_abort(struct se_cmd *cmd)
{
	/*
	 * If there are still expected incoming fabric WRITEs, we wait
	 * until until they have completed before sending a TASK_ABORTED
	 * response.  This response with TASK_ABORTED status will be
	 * queued back to fabric module by transport_check_aborted_status().
	 */
	if (cmd->data_direction == DMA_TO_DEVICE) {
		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
			atomic_inc(&cmd->t_task.t_transport_aborted);
			smp_mb__after_atomic_inc();
			cmd->scsi_status = SAM_STAT_TASK_ABORTED;
			transport_new_cmd_failure(cmd);
			return;
		}
	}
	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
#if 0
	printk(KERN_INFO "Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
		" ITT: 0x%08x\n", cmd->t_task.t_task_cdb[0],
		cmd->se_tfo->get_task_tag(cmd));
#endif
	cmd->se_tfo->queue_status(cmd);
}

/*	transport_generic_do_tmr():
 *
 *
 */
int transport_generic_do_tmr(struct se_cmd *cmd)
{
	struct se_cmd *ref_cmd;
	struct se_device *dev = cmd->se_dev;
	struct se_tmr_req *tmr = cmd->se_tmr_req;
	int ret;

	switch (tmr->function) {
	case TMR_ABORT_TASK:
		ref_cmd = tmr->ref_cmd;
		tmr->response = TMR_FUNCTION_REJECTED;
		break;
	case TMR_ABORT_TASK_SET:
	case TMR_CLEAR_ACA:
	case TMR_CLEAR_TASK_SET:
		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
		break;
	case TMR_LUN_RESET:
		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
					 TMR_FUNCTION_REJECTED;
		break;
	case TMR_TARGET_WARM_RESET:
		tmr->response = TMR_FUNCTION_REJECTED;
		break;
	case TMR_TARGET_COLD_RESET:
		tmr->response = TMR_FUNCTION_REJECTED;
		break;
	default:
		printk(KERN_ERR "Uknown TMR function: 0x%02x.\n",
				tmr->function);
		tmr->response = TMR_FUNCTION_REJECTED;
		break;
	}

	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
	cmd->se_tfo->queue_tm_rsp(cmd);

	transport_cmd_check_stop(cmd, 2, 0);
	return 0;
}

/*
 *	Called with spin_lock_irq(&dev->execute_task_lock); held
 *
 */
static struct se_task *
transport_get_task_from_state_list(struct se_device *dev)
{
	struct se_task *task;

	if (list_empty(&dev->state_task_list))
		return NULL;

	list_for_each_entry(task, &dev->state_task_list, t_state_list)
		break;

	list_del(&task->t_state_list);
	atomic_set(&task->task_state_active, 0);

	return task;
}

static void transport_processing_shutdown(struct se_device *dev)
{
	struct se_cmd *cmd;
	struct se_task *task;
	unsigned long flags;
	/*
	 * Empty the struct se_device's struct se_task state list.
	 */
	spin_lock_irqsave(&dev->execute_task_lock, flags);
	while ((task = transport_get_task_from_state_list(dev))) {
		if (!task->task_se_cmd) {
			printk(KERN_ERR "task->task_se_cmd is NULL!\n");
			continue;
		}
		cmd = task->task_se_cmd;

		spin_unlock_irqrestore(&dev->execute_task_lock, flags);

		spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);

		DEBUG_DO("PT: cmd: %p task: %p ITT/CmdSN: 0x%08x/0x%08x,"
			" i_state/def_i_state: %d/%d, t_state/def_t_state:"
			" %d/%d cdb: 0x%02x\n", cmd, task,
			cmd->se_tfo->get_task_tag(cmd), cmd->cmd_sn,
			cmd->se_tfo->get_cmd_state(cmd), cmd->deferred_i_state,
			cmd->t_state, cmd->deferred_t_state,
			cmd->t_task.t_task_cdb[0]);
		DEBUG_DO("PT: ITT[0x%08x] - t_task_cdbs: %d t_task_cdbs_left:"
			" %d t_task_cdbs_sent: %d -- t_transport_active: %d"
			" t_transport_stop: %d t_transport_sent: %d\n",
			cmd->se_tfo->get_task_tag(cmd),
			cmd->t_task.t_task_cdbs,
			atomic_read(&cmd->t_task.t_task_cdbs_left),
			atomic_read(&cmd->t_task.t_task_cdbs_sent),
			atomic_read(&cmd->t_task.t_transport_active),
			atomic_read(&cmd->t_task.t_transport_stop),
			atomic_read(&cmd->t_task.t_transport_sent));

		if (atomic_read(&task->task_active)) {
			atomic_set(&task->task_stop, 1);
			spin_unlock_irqrestore(
				&cmd->t_task.t_state_lock, flags);

			DEBUG_DO("Waiting for task: %p to shutdown for dev:"
				" %p\n", task, dev);
			wait_for_completion(&task->task_stop_comp);
			DEBUG_DO("Completed task: %p shutdown for dev: %p\n",
				task, dev);

			spin_lock_irqsave(&cmd->t_task.t_state_lock, flags);
			atomic_dec(&cmd->t_task.t_task_cdbs_left);

			atomic_set(&task->task_active, 0);
			atomic_set(&task->task_stop, 0);
		} else {
			if (atomic_read(&task->task_execute_queue) != 0)
				transport_remove_task_from_execute_queue(task, dev);
		}
		__transport_stop_task_timer(task, &flags);

		if (!(atomic_dec_and_test(&cmd->t_task.t_task_cdbs_ex_left))) {
			spin_unlock_irqrestore(
					&cmd->t_task.t_state_lock, flags);

			DEBUG_DO("Skipping task: %p, dev: %p for"
				" t_task_cdbs_ex_left: %d\n", task, dev,
				atomic_read(&cmd->t_task.t_task_cdbs_ex_left));

			spin_lock_irqsave(&dev->execute_task_lock, flags);
			continue;
		}

		if (atomic_read(&cmd->t_task.t_transport_active)) {
			DEBUG_DO("got t_transport_active = 1 for task: %p, dev:"
					" %p\n", task, dev);

			if (atomic_read(&cmd->t_task.t_fe_count)) {
				spin_unlock_irqrestore(
					&cmd->t_task.t_state_lock, flags);
				transport_send_check_condition_and_sense(
					cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE,
					0);
				transport_remove_cmd_from_queue(cmd,
					&cmd->se_dev->dev_queue_obj);

				transport_lun_remove_cmd(cmd);
				transport_cmd_check_stop(cmd, 1, 0);
			} else {
				spin_unlock_irqrestore(
					&cmd->t_task.t_state_lock, flags);

				transport_remove_cmd_from_queue(cmd,
					&cmd->se_dev->dev_queue_obj);

				transport_lun_remove_cmd(cmd);

				if (transport_cmd_check_stop(cmd, 1, 0))
					transport_generic_remove(cmd, 0, 0);
			}

			spin_lock_irqsave(&dev->execute_task_lock, flags);
			continue;
		}
		DEBUG_DO("Got t_transport_active = 0 for task: %p, dev: %p\n",
				task, dev);

		if (atomic_read(&cmd->t_task.t_fe_count)) {
			spin_unlock_irqrestore(
				&cmd->t_task.t_state_lock, flags);
			transport_send_check_condition_and_sense(cmd,
				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
			transport_remove_cmd_from_queue(cmd,
				&cmd->se_dev->dev_queue_obj);

			transport_lun_remove_cmd(cmd);
			transport_cmd_check_stop(cmd, 1, 0);
		} else {
			spin_unlock_irqrestore(
				&cmd->t_task.t_state_lock, flags);

			transport_remove_cmd_from_queue(cmd,
				&cmd->se_dev->dev_queue_obj);
			transport_lun_remove_cmd(cmd);

			if (transport_cmd_check_stop(cmd, 1, 0))
				transport_generic_remove(cmd, 0, 0);
		}

		spin_lock_irqsave(&dev->execute_task_lock, flags);
	}
	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
	/*
	 * Empty the struct se_device's struct se_cmd list.
	 */
	while ((cmd = transport_get_cmd_from_queue(&dev->dev_queue_obj))) {

		DEBUG_DO("From Device Queue: cmd: %p t_state: %d\n",
				cmd, cmd->t_state);

		if (atomic_read(&cmd->t_task.t_fe_count)) {
			transport_send_check_condition_and_sense(cmd,
				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);

			transport_lun_remove_cmd(cmd);
			transport_cmd_check_stop(cmd, 1, 0);
		} else {
			transport_lun_remove_cmd(cmd);
			if (transport_cmd_check_stop(cmd, 1, 0))
				transport_generic_remove(cmd, 0, 0);
		}
	}
}

/*	transport_processing_thread():
 *
 *
 */
static int transport_processing_thread(void *param)
{
	int ret;
	struct se_cmd *cmd;
	struct se_device *dev = (struct se_device *) param;

	set_user_nice(current, -20);

	while (!kthread_should_stop()) {
		ret = wait_event_interruptible(dev->dev_queue_obj.thread_wq,
				atomic_read(&dev->dev_queue_obj.queue_cnt) ||
				kthread_should_stop());
		if (ret < 0)
			goto out;

		spin_lock_irq(&dev->dev_status_lock);
		if (dev->dev_status & TRANSPORT_DEVICE_SHUTDOWN) {
			spin_unlock_irq(&dev->dev_status_lock);
			transport_processing_shutdown(dev);
			continue;
		}
		spin_unlock_irq(&dev->dev_status_lock);

get_cmd:
		__transport_execute_tasks(dev);

		cmd = transport_get_cmd_from_queue(&dev->dev_queue_obj);
		if (!cmd)
			continue;

		switch (cmd->t_state) {
		case TRANSPORT_NEW_CMD_MAP:
			if (!(cmd->se_tfo->new_cmd_map)) {
				printk(KERN_ERR "cmd->se_tfo->new_cmd_map is"
					" NULL for TRANSPORT_NEW_CMD_MAP\n");
				BUG();
			}
			ret = cmd->se_tfo->new_cmd_map(cmd);
			if (ret < 0) {
				cmd->transport_error_status = ret;
				transport_generic_request_failure(cmd, NULL,
						0, (cmd->data_direction !=
						    DMA_TO_DEVICE));
				break;
			}
			/* Fall through */
		case TRANSPORT_NEW_CMD:
			ret = transport_generic_new_cmd(cmd);
			if (ret < 0) {
				cmd->transport_error_status = ret;
				transport_generic_request_failure(cmd, NULL,
					0, (cmd->data_direction !=
					 DMA_TO_DEVICE));
			}
			break;
		case TRANSPORT_PROCESS_WRITE:
			transport_generic_process_write(cmd);
			break;
		case TRANSPORT_COMPLETE_OK:
			transport_stop_all_task_timers(cmd);
			transport_generic_complete_ok(cmd);
			break;
		case TRANSPORT_REMOVE:
			transport_generic_remove(cmd, 1, 0);
			break;
		case TRANSPORT_FREE_CMD_INTR:
			transport_generic_free_cmd(cmd, 0, 1, 0);
			break;
		case TRANSPORT_PROCESS_TMR:
			transport_generic_do_tmr(cmd);
			break;
		case TRANSPORT_COMPLETE_FAILURE:
			transport_generic_request_failure(cmd, NULL, 1, 1);
			break;
		case TRANSPORT_COMPLETE_TIMEOUT:
			transport_stop_all_task_timers(cmd);
			transport_generic_request_timeout(cmd);
			break;
		default:
			printk(KERN_ERR "Unknown t_state: %d deferred_t_state:"
				" %d for ITT: 0x%08x i_state: %d on SE LUN:"
				" %u\n", cmd->t_state, cmd->deferred_t_state,
				cmd->se_tfo->get_task_tag(cmd),
				cmd->se_tfo->get_cmd_state(cmd),
				cmd->se_lun->unpacked_lun);
			BUG();
		}

		goto get_cmd;
	}

out:
	transport_release_all_cmds(dev);
	dev->process_thread = NULL;
	return 0;
}